Search results
Search for "glycoside" in Full Text gives 143 result(s) in Beilstein Journal of Organic Chemistry.
Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins
- Zhongwei Hua,
- Nan Liu and
- Xiaohui Yan
Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68
- pharmaceutical industries [5]. They exhibit a broad spectrum of pharmacological activity, including antitumor [6], anti-inflammatory [7], hepatoprotective [8], nephroprotective [9], antidepressant [10], antioxidant [11], and antidiabetic [12] properties. The Saffron Multi-glycoside Tablet (Xihonghua Zonggan Pian
Graphical Abstract
Figure 1: Principal structure of crocin and crocetin derivatives, including common substituents of the crocet...
Figure 2: The pharmacological activity and mechanisms of action of crocins.
Figure 3: Crocin biosynthetic pathways in C. sativus and G. jasminoides. Enzyme abbreviations are as follows:...
Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium
- Kairi Umeda,
- Naoaki Kurisawa,
- Ghulam Jeelani,
- Tomoyoshi Nozaki,
- Kiyotake Suenaga and
- Arihiro Iwasaki
Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57
- polycavernosides. Keywords: macrolide glycoside; marine cyanobacterium; marine natural products; polycavernosides; terminal alkyne; Introduction In 1991, an outbreak of food poisoning caused by a species of red algae known as ‘Polycavernosa tsudai’ occurred in Guam, which resulted in killing of three people. Two
Graphical Abstract
Figure 1: Structures of compounds 1, 2, and 5.
Figure 2: Planar structure of polycavernoside E (1) based on 2D NMR analysis.
Figure 3: Relative configuration of the THP ring and disaccharide moiety of 1.
Figure 4: ECD spectrum of 1 in MeOH.
Synthesis of ether lipids: natural compounds and analogues
- Marco Antônio G. B. Gomes,
- Alicia Bauduin,
- Chloé Le Roux,
- Romain Fouinneteau,
- Wilfried Berthe,
- Mathieu Berchel,
- Hélène Couthon and
- Paul-Alain Jaffrès
Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96
Graphical Abstract
Figure 1: Chemical structure of some natural ether lipids (ELs).
Figure 2: Synthesis of lyso-PAF and PAF from 1-O-alkylglycerol [64].
Figure 3: Synthesis of lyso-PAF from 1,3-benzylideneglycerol 3.1 [69].
Figure 4: A) Synthesis of the two enantiomers of octadecylglycerol (4.6 and 4.10) from ᴅ-mannitol (4.1); B) s...
Figure 5: Four-step synthesis of PAF 5.6 from (S)-glycidol [73].
Figure 6: Synthesis of 1-O-alkylglycerol A) from solketal, B) from ᴅ- or ʟ-tartaric acid and the intermediate ...
Figure 7: Synthesis of EL building blocks starting from substituted glycidol 7.1a–c [82].
Figure 8: Synthesis of PAF 8.5 by using phosphoramidite 8.2 [86].
Figure 9: Synthesis of oleyl-PAF 9.7 from ʟ-serine [88].
Figure 10: Synthesis of racemic analogues of lyso-PAF 10.8 and PAF 10.9 featuring a phenyl group between the g...
Figure 11: Synthesis of racemic deoxy-lyso-PAF 11.7 and deoxy-PAF 11.8 [91].
Figure 12: Synthesis of racemic thio-PAF 12.8 [93].
Figure 13: Racemic synthesis of 13.6 to illustrate the modification of the glycerol backbone by adding a methy...
Figure 14: Racemic synthesis of 14.5 as an illustration of the introduction of methyl substituents on the glyc...
Figure 15: Synthesis of functionalized sn-2-acyl chains of PC-EL; A) Steglich esterification or acylation reac...
Figure 16: Synthesis of racemic mc-PAF (16.3), a carbamate analogue of PAF [102].
Figure 17: A) Synthesis of (R)-17.2 and (S)-17.6 starting from (S)-solketal (17.1); B) synthesis of N3-PAF (17...
Figure 18: Modification of the phosphocholine polar head to produce PAF analogues [81].
Figure 19: Racemic PAF analogues 19.3 and 19.5 characterized by the absence of the phosphate group [107].
Figure 20: Synthesis of PIP3-PAF (20.7) [108].
Figure 21: Large-scale synthesis of C18-edelfosine (21.8) [116].
Figure 22: Synthesis of C16-edelfosine (22.10) starting from isopropylidene-ʟ-glyceric acid methyl ester (22.1...
Figure 23: Phosphocholine moiety installation by the use of chlorophosphite 23.2 as key reagent [119].
Figure 24: Synthesis of rac-1-alkyl-2-O-methylglycerol (AMG) [120].
Figure 25: Synthesis of stereocontrolled 1-alkyl-2-O-methyl glycerol 25.9 (AMG) from dimethyl ᴅ-tartrate [81].
Figure 26: A) Racemic synthesis of thioether 26.4 [129,130], B) structure of sulfone analogue 26.5 [129].
Figure 27: Stereocontrolled synthesis of C18-edelfosine thioether analogue 27.8 [118].
Figure 28: Synthesis of thioether 28.4 that include a thiophosphate function [134].
Figure 29: Synthesis of ammonium thioether 29.4 and 29.6 [135].
Figure 30: Synthesis of the N-methylamino analogue of edelfosine 30.6 (BN52211) [138].
Figure 31: Synthesis of 1-desoxy analogues of edelfosine; A) with a saturated alkyl chain; B) synthesis of the...
Figure 32: Stereocontrolled synthesis of edelfosine analogue (S)-32.8 featuring a C18:1 lipid chain [142].
Figure 33: Synthesis of edelfosine analogues with modulation of the lipid chain; A) illustration with the synt...
Figure 34: Synthesis of phospholipid featuring a carbamate function to link the lipid chain to the glycerol un...
Figure 35: Synthesis of sesquiterpene conjugates of phospho glycero ether lipids [148].
Figure 36: Racemic synthesis of methyl-substituted glycerol analogues 36.7 and 36.10: A) synthesis of diether ...
Figure 37: Racemic synthesis of ilmofosine (37.6) [155,156].
Figure 38: A) Stereoselective synthesis of 38.5 via a stereoselective hydroboration reaction; B) synthesis of ...
Figure 39: Racemic synthesis of SRI62-834 (39.6) featuring a spiro-tetrahydrofurane heterocycle in position 2 ...
Figure 40: Racemic synthesis of edelfosine analogue 40.5 featuring an imidazole moiety in sn-2 position [160].
Figure 41: Racemic synthesis of fluorine-functionalized EL: A) Synthesis of 41.6 and B) synthesis of 41.8 [161-163].
Figure 42: A) Synthesis of the β-keto-ester 42.6 that also features a decyl linker between the phosphate and t...
Figure 43: Synthesis of phosphonate-based ether lipids; A) edelfosine phosphonate analogue 43.7 and B) thioeth...
Figure 44: Enantioselective synthesis of phosphonates 44.3 and 44.4 [171].
Figure 45: Racemic synthesis of phosphinate-based ether lipid 45.10 [172].
Figure 46: Racemic synthesis of edelfosine arsonium analogue 46.5 [173].
Figure 47: Synthesis of edelfosine dimethylammonium analogue 47.2 [118].
Figure 48: Synthesis of rac-C18-edelfosine methylammonium analogue 48.4 [176].
Figure 49: A) Synthesis of edelfosine N-methylpyrrolidinium analogue 49.2 or N-methylmorpholinium analogue 49.3...
Figure 50: A) Synthesis of edelfosine’s analogue 50.4 with a PE polar group; B) illustration of a pyridinium d...
Figure 51: A) Synthesis of 51.4 featuring a thiazolium cationic moiety; B) synthesis of thiazolium-based EL 51...
Figure 52: Synthesis of cationic ether lipids 52.3, 52.4 and 52.6 [135,183].
Figure 53: Synthesis of cationic carbamate ether lipid 53.5 [184].
Figure 54: Synthesis of cationic sulfonamide 54.5 [185].
Figure 55: Chemical structure of ONO-6240 (55.1) and SRI-63-119 (55.2).
Figure 56: Synthesis of non-ionic ether lipids 56.2–56.9 [188].
Figure 57: Synthesis of ether lipid conjugated to foscarnet 57.6 [189].
Figure 58: A) Synthesis of ether lipid conjugated to arabinofuranosylcytosine; B) synthesis of AZT conjugated ...
Figure 59: Synthesis of quercetin conjugate to edelfosine [191].
Figure 60: Synthesis of 60.8 (Glc-PAF) [194].
Figure 61: A) Synthesis of amino ether lipid 61.7 functionalized with a rhamnose unit and its amide analogue 6...
Figure 62: A) Synthesis of glucose ether lipid 62.4; B) structure of ether lipid 62.5 possessing a maltose uni...
Figure 63: A) Synthesis of glucuronic methyl ester 63.8; B) structure of cellobiose 63.9 and maltose 63.10 ana...
Figure 64: A) Synthesis of maltosyl glycerolipid 64.7; B) structure of lactose analogue 64.8 prepared followin...
Figure 65: A) Asymmetric synthesis of the aglycone moiety starting from allyl 4-methoxyphenyl ether; B) glycos...
Figure 66: A) Synthesis of ohmline possessing a lactose moiety. B) Structure of other glyco glycero lipids pre...
Figure 67: A) Synthesis of lactose-glycerol ether lipid 67.5; B) analogues possessing a maltose (67.6) or meli...
Figure 68: Synthesis of digalactosyl EL 68.6, A) by using trityl, benzyl and acetyl protecting groups, B) by u...
Figure 69: A) Synthesis of α-ohmline; B) structure of disaccharide ether lipids prepared by using similar meth...
Figure 70: Synthesis of lactose ether lipid 70.3 and its analogue 70.6 featuring a carbamate function as linke...
Figure 71: Synthesis of rhamnopyranoside diether 71.4 [196].
Figure 72: Synthesis of 1-O-hexadecyl-2-O-methyl-3-S-(α-ᴅ-1'-thioglucopyranosyl)-sn-glycerol (72.5) [225].
Figure 73: A) Preparation of lipid intermediate 73.4; B) synthesis of 2-desoxy-C-glycoside 73.10 [226].
Figure 74: Synthesis of galactose-pyridinium salt 74.3 [228].
Figure 75: Synthesis of myo-inositol derivative Ino-C2-PAF (75.10) [230].
Figure 76: A) Synthesis of myo-inositol phosphate building block 76.7; B) synthesis of myo-inositolphosphate d...
Figure 77: A) Synthesis of phosphatidyl-3-desoxy-inositol 77.4; B) synthesis of phosphono-3-desoxyinositol 77.9...
Figure 78: A) Structure of diether phosphatidyl-myo-inositol-3,4-diphosphate 78.1; B) synthesis of phosphatidy...
Figure 79: A) Synthesis of diether-phosphatidyl derivative 79.4 featuring a hydroxymethyl group in place of a ...
Figure 80: Synthesis of Glc-amine-PAF [78].
Figure 81: Synthesis of glucosamine ether lipid 81.4 and its analogues functionalized in position 3 of the ami...
Figure 82: Synthesis of fully deprotected aminoglucoside ether lipid 82.5 [246].
Figure 83: Synthesis of C-aminoglycoside 83.12 using Ramberg–Bäcklund rearrangement as a key step [250].
Figure 84: A) List of the most important glyco lipids and amino glyco lipids included in the study of Arthur a...
Figure 85: Synthesis of mannosamine ether lipid 85.6 [254].
Figure 86: A) Synthesis of glucosamine ether lipids with a non-natural ʟ-glucosamine moiety; B) synthesis of e...
Figure 87: A) Structure of the most efficient anticancer agents 87.1–87.4 featuring a diamino glyco ether lipi...
Figure 88: A) Synthesis of diamino glyco ether lipid 87.4; B) synthesis of bis-glycosylated ether lipid 88.10 [256]....
Figure 89: Synthesis of triamino ether lipid 89.4 [260].
Figure 90: Synthesis of chlorambucil conjugate 90.7 [261].
Figure 91: Three main methods for the preparation of glycerol ether lipid 91.3; A) from solketal and via a tri...
Figure 92: Four different methods for the installation of the phosphocholine polar head group; A) method using...
Figure 93: Illustration of two methods for the installation of saccharides or aminosaccharides; A) O-glycosyla...
Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea
- Winnie Chemutai Sum,
- Sherif S. Ebada,
- Didsanutda Gonkhom,
- Cony Decock,
- Rémy Bertrand Teponno,
- Josphat Clement Matasyoh and
- Marc Stadler
Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84
- inducing cytotoxicity. In addition, another study demonstrated that a lanostanoid glycoside derivative with a glucosyl ester at the C-21 carboxylic acid group was active in a cytotoxic activity assay, whereas the galactosyl ester counterpart was inactive [36]. Similarly, the carboxylic acid group at C-21
Graphical Abstract
Figure 1: Chemical structures of compounds 1–4.
Figure 2: Key 1H,1H COSY, HMBC, and ROESY correlations of compounds 1 and 2.
Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles
- Péter Kisszékelyi and
- Radovan Šebesta
Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44
- :1). Additional transformation of compound 230 following an A–AB–ABC synthetic strategy resulted in the desired complex tricyclic skeleton opening the door for the total synthesis of 12-epi-JBIR-23/24 (Scheme 61). The sulfated β-glycoside peyssonnoside A was isolated only recently from the red algae
Graphical Abstract
Scheme 1: General scheme depicting tandem reactions based on an asymmetric conjugate addition followed by an ...
Scheme 2: Cu-catalyzed tandem conjugate addition of R2Zn/aldol reaction with chiral acetals.
Scheme 3: Cu-catalyzed asymmetric desymmetrization of cyclopentene-1,3-diones using a tandem conjugate additi...
Scheme 4: Stereocontrolled assembly of dialkylzincs, cyclic enones, and sulfinylimines utilizing a Cu-catalyz...
Scheme 5: Cu-catalyzed tandem conjugate addition/Mannich reaction (A). Access to chiral isoindolinones and tr...
Scheme 6: Cu-catalyzed tandem conjugate addition/nitro-Mannich reaction (A) with syn–anti or syn–syn selectiv...
Figure 1: Various chiral ligands utilized for the tandem conjugate addition/Michael reaction sequences.
Scheme 7: Cu-catalyzed tandem conjugate addition/Michael reaction: side-product formation with chalcone (A) a...
Scheme 8: Zn enolate trapping using allyl iodides (A), Stork–Jung vinylsilane reagents (B), and allyl bromide...
Scheme 9: Cu-catalyzed tandem conjugate addition/acylation through Li R2Zn enolate (A). A four-component coup...
Scheme 10: Selected examples for the Cu-catalyzed tandem conjugate addition/trifluoromethylthiolation sequence....
Scheme 11: Zn enolates trapped by vinyloxiranes: synthesis of allylic alcohols.
Scheme 12: Stereoselective cyclopropanation of Mg enolates formed by ACA of Grignard reagents to chlorocrotona...
Scheme 13: Domino aldol reactions of Mg enolates formed from coumarin and chromone.
Scheme 14: Oxidative coupling of ACA-produced Mg enolates.
Scheme 15: Tandem ACA of Grignard reagents to enones and Mannich reaction.
Scheme 16: Diastereodivergent Mannich reaction of Mg enolates with differently N-protected imines.
Scheme 17: Tandem Grignard–ACA–Mannich using Taddol-based phosphine-phosphite ligands.
Scheme 18: Tandem reaction of Mg enolates with aminomethylating reagents.
Scheme 19: Tandem reaction composed of Grignard ACA to alkynyl enones.
Scheme 20: Rh/Cu-catalyzed tandem reaction of diazo enoates leading to cyclobutanes.
Scheme 21: Tandem Grignard-ACA of cyclopentenones and alkylation of enolates.
Scheme 22: Tandem ACA of Grignard reagents followed by enolate trapping reaction with onium compounds.
Scheme 23: Mg enolates generated from unsaturated lactones in reaction with activated alkenes.
Scheme 24: Lewis acid mediated ACA to amides and SN2 cyclization of a Br-appended enolate.
Scheme 25: Trapping reactions of aza-enolates with Michael acceptors.
Scheme 26: Si enolates generated by TMSOTf-mediated ACA of Grignard reagents and enolate trapping reaction wit...
Scheme 27: Trapping reactions of enolates generated from alkenyl heterocycles (A) and carboxylic acids (B) wit...
Scheme 28: Reactions of heterocyclic Mg enolates with onium compounds.
Scheme 29: Synthetic transformations of cycloheptatrienyl and benzodithiolyl substituents.
Scheme 30: Aminomethylation of Al enolates generated by ACA of trialkylaluminum reagents.
Scheme 31: Trapping reactions of enolates with activated alkenes.
Scheme 32: Alkynylation of racemic aluminum or magnesium enolates.
Scheme 33: Trapping reactions of Zr enolates generated by Cu-ACA of organozirconium reagents.
Scheme 34: Chloromethylation of Zr enolates using the Vilsmeier–Haack reagent.
Scheme 35: Tandem conjugate borylation with subsequent protonation or enolate trapping by an electrophile.
Scheme 36: Tandem conjugate borylation/aldol reaction of cyclohexenones.
Scheme 37: Selected examples for the tandem asymmetric borylation/intramolecular aldol reaction; synthesis of ...
Scheme 38: Cu-catalyzed tandem methylborylation of α,β-unsaturated phosphine oxide in the presence of (R,Sp)-J...
Scheme 39: Cu-catalyzed tandem transannular conjugated borylation/aldol cyclization of macrocycles containing ...
Scheme 40: Stereoselective tandem conjugate borylation/Mannich cyclization: selected examples (A) and a multi-...
Scheme 41: Some examples of Cu-catalyzed asymmetric tandem borylation/aldol cyclization (A). Application to di...
Scheme 42: Atropisomeric P,N-ligands used in tandem conjugate borylation/aldol cyclization sequence.
Scheme 43: Selected examples for the enantioselective Cu-catalyzed borylation/intramolecular Michael addition ...
Scheme 44: Selected examples for the preparation of enantioenriched spiroindanes using a Cu-catalyzed tandem c...
Scheme 45: Enantioselective conjugate borylation of cyclobutene-1-carboxylic acid diphenylmethyl ester 175 wit...
Scheme 46: Cu-catalyzed enantioselective tandem conjugate silylation of α,β-unsaturated ketones with subsequen...
Scheme 47: Cu-catalyzed enantioselective tandem conjugate silylation of α,β-unsaturated ketones with subsequen...
Scheme 48: Cu-catalyzed tandem conjugate silylation/aldol condensation. The diastereoselectivity is controlled...
Scheme 49: Chiral Ru-catalyzed three-component coupling reaction.
Scheme 50: Rh-Phebox complex-catalyzed reductive cyclization and subsequent reaction with Michael acceptors th...
Scheme 51: Rh-catalyzed tandem asymmetric conjugate alkynylation/aldol reaction (A) and subsequent spiro-cycli...
Scheme 52: Rh-bod complex-catalyzed tandem asymmetric conjugate arylation/intramolecular aldol addition (A). S...
Scheme 53: Co-catalyzed C–H-bond activation/asymmetric conjugate addition/aldol reaction.
Scheme 54: (Diisopinocampheyl)borane-promoted 1,4-hydroboration of α,β-unsaturated morpholine carboxamides and...
Figure 2: Some examples of total syntheses that have been recently reviewed.
Scheme 55: Stereoselective synthesis of antimalarial prodrug (+)-artemisinin utilizing a tandem conjugate addi...
Scheme 56: Amphilectane and serrulatane diterpenoids: preparation of chiral starting material via asymmetric t...
Scheme 57: Various asymmetric syntheses of pleuromutilin and related compounds based on a tandem conjugate add...
Scheme 58: Total synthesis of glaucocalyxin A utilizing a tandem conjugate addition/acylation reaction sequenc...
Scheme 59: Installation of the exocyclic double bond using a tandem conjugate addition/aminomethylation sequen...
Scheme 60: Synthesis of the taxol core using a tandem conjugate addition/enolate trapping sequence with Vilsme...
Scheme 61: Synthesis of the tricyclic core of 12-epi-JBIR-23/24 utilizing a Rh-catalyzed asymmetric conjugate ...
Scheme 62: Total synthesis of (−)-peyssonoside A utilizing a Cu-catalyzed enantioselective tandem conjugate ad...
Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis
- Nicoleta G. Hădărugă,
- Gabriela Popescu,
- Dina Gligor (Pane),
- Cristina L. Mitroi,
- Sorin M. Stanciu and
- Daniel Ioan Hădărugă
Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30
- [64][65][66]. The goal of this study was the synthesis of β-CD/hazelnut (Corylus avellana L.) oil/flavonoid glycoside or flavonolignan ternary complexes (Figure 1) and the discrimination of these complexes by FTIR–PCA. These innovative ternary complexes were synthesized for the first time and can
- kneading method as the most appropriate one for obtaining β-CD/hazelnut (Corylus avellana L.) oil/flavonoid glycoside or flavonolignan ternary complexes. Kneading allows for higher recovery yields of complexes in comparison with the co-crystallization method because only small amounts of solvent are needed
- discrimination of such ternary complexes on the basis of FTIR. The evaluation of the encapsulation competitiveness of such multicomponent mixtures is very challenging (highly hydrophobic FA triglycerides, mono- and diglycerides, free FAs, as well as more hydrophilic flavonoid glycoside, namely hesperidin
Graphical Abstract
Figure 1: Hypothetical interactions between the β-cyclodextrin host and guest molecules (flavonoid glycoside/...
Figure 2: Superposition of the FTIR spectra for the β-cyclodextrin/Corylus avellana oil/hesperidin ternary co...
Figure 3: Superposition of the FTIR spectra for the β-cyclodextrin/Corylus avellana oil/hesperidin ternary co...
Figure 4: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the flavonoid glycoside and flavonolignan ...
Figure 5: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 6: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 7: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 8: PC3 versus PC1 scores plot from the FTIR-PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 9: PC3 versus PC2 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 10: PC2 versus PC1 loadings plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary ...
Figure 11: PC3 versus PC1 loadings plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary ...
Figure 12: Eigenvalues of the correlation matrix from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid...
Preparation of β-cyclodextrin/polysaccharide foams using saponin
- Max Petitjean and
- José Ramón Isasi
Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7
- molecules into the cavity of the glycoside micelles should be taken into account. Our main goal in this part of the study is to guarantee that the prepared foams remain stable at least until the crosslinking reaction takes place. Once the six experimental synthetic paths were set (see Experimental section
Graphical Abstract
Figure 1: Quillaja saponin foamability (left) and foam stability over time for the β-cyclodextrin/polysacchar...
Figure 2: SEM images of crushed β-c-LBG as a function of the synthesis pathways (see below, Experimental sect...
Figure 3: SEM of β-csp after crosslinking with or without washing the sample.
Figure 4: β-csp (left) and c-CSsp (right) matrices unwashed showing the “foam-like” morphologies.
Figure 5: Values (in mg/g) of equivalent ‘free β-cyclodextrin’ in the polysaccharide (PS) matrices, as a func...
Figure 6: 1-Naphthol isotherms of crosslinked β-cyclodextrin/polysaccharides (blue curves for chitosan, red f...
Figure 7: Sorption of phenols (V, vanillin; Ph, phenol; m-c, m-cresol; 4eP, 4-ethylphenol; Eu, eugenol) in β-...
Figure 8: Six synthesis routes (*lyophilized matrices) used to prepare samples β-c-XGsp; β-c-LBGsp; β-c-CSsp ...
Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase
- Peterson de Andrade,
- Sanaz Ahmadipour and
- Robert A. Field
Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24
- typically found as a terminal unit of surface glycoconjugates and is crucial to various cellular recognition events in both physiological and pathological processes [1]. This distinctive negatively charged monosaccharide is the natural substrate for sialidases, which belong to different glycoside hydrolase
- anomeric configuration of 1 was based on the chemical shift of H3eq, which is located in lower magnetic field (over 2.5 ppm) when compared to a β-glycoside (under 2.5 ppm) [27]. Additionally, the anomeric configuration can be determined through the coupling pattern of C-1 in a selective proton decoupled
Graphical Abstract
Figure 1: Chemical structures and reported activities of viral (A), human neuraminidases (B) and Trypanosoma ...
Figure 2: Design and synthesis of potential neuraminidase and trans-sialidase inhibitors exploiting a moiety ...
Figure 3: TcTS and neuraminidase hydrolase activity (A) as well as TcTS transferase activity (B) in the prese...
Figure 4: TcTS and neuraminidase inhibition by 1,2,3-triazole-linked sialic acid derivatives 3a–h (1 mM) usin...
Figure 5: Crystal structure of TcTS (PDB code 1MS1 – coloured red) (A) and neuraminidase (PDB code 2VK6 – col...
Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities
- Meifang Wu,
- Xiangdong Su,
- Yichuang Wu,
- Yuanjing Luo,
- Ying Guo and
- Yongbo Xue
Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23
- 106.8, 103.0, 79.0, 78.9, 77.9, 75.4, 74.8, 71.4, 71.5), as well as two oxygenated methylenes resonated at δC 70.6, and 67.7, respectively. The aforementioned information suggested that compound 1 is likely a bis-coumarin glycoside [9]. The substructures A and B (Figure 2 and Figure 3) were elucidated
Graphical Abstract
Figure 1: Chemical structures of compounds 1–17 from W. nutans.
Figure 2: The key correlations observed in the 1H-1H COSY (bold bonds), HMBC (blue) correlations of 1 (record...
Figure 3: The key correlations observed in the 1H-1H COSY (bold bonds), HMBC (blue), ROESY (red) of 1 (record...
Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes
- Shun Saito,
- Kanji Indo,
- Naoya Oku,
- Hisayuki Komaki,
- Masashi Kawasaki and
- Yasuhiro Igarashi
Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203
- Streptomyces, are especially noted, accounting for more than 800 metabolites of actinomycetes origin [11], which include the antiinfective aminoglycoside gentamicin [13], antidiabetic glycoside acarbose [14], glycopeptide antibiotic teicoplanin [15], enediyne antitumor component of drug-antibody conjugate
Graphical Abstract
Figure 1: Structures of 1–6.
Figure 2: COSY, key HMBC and NOESY correlations of 1–5.
Figure 3: 1H NMR spectra and partial chemical shift assignments for MPA esters 4'a–4'd. Upper: (R)-MPA acylat...
Figure 4: Chiral phase HPLC analysis of methyl ester 4'. Italicized numbers indicate peak areas.
Figure 5: COSY and key HMBC correlations observed for 6.
Figure 6: ΔδH(S-R) values in ppm calculated from PGME amides 6a and 6b.
Figure 7: Selected examples of the related compounds derived from the strains in the genus Streptomyces (a) a...
Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies
- Tanmoy Halder and
- Somnath Yadav
Beilstein J. Org. Chem. 2021, 17, 2915–2921, doi:10.3762/bjoc.17.199
- was then deprotected and N-acetylated to finally afford the desired trisaccharide repeating unit as its α-p-methoxyphenyl glycoside. Keywords: capsular polysaccharide; carbohydrate vaccines; O-antigen; oligosaccharide synthesis; one-pot synthesis; Introduction O-antigens or O-specific
- -methoxyphenyl glycoside form 1 was synthesized through a linear [1 + (1 + 1 = 2)] strategy. The target trisaccharide was synthesized as its p-methoxyphenyl glycoside that offered the unaltered stereochemistry of the sugar at the reducing end to mimic the glycosidic linkage of the natural polysaccharide. The
- stereoselective glycosylations. The work provides an access to the trisaccharide repeating unit of the O-polysaccharide of Providencia stuartii O49 with the stereospecific α-p-methoxyphenyl glycoside. Structure of the repeating unit of the lipopolysaccharide of Providencia stuartii O49 serotype. Retrosynthetic
Graphical Abstract
Figure 1: Structure of the repeating unit of the lipopolysaccharide of Providencia stuartii O49 serotype.
Scheme 1: Retrosynthetic analysis for the synthesis of the target trisaccharide 1.
Scheme 2: Synthesis of the monosaccharide building blocks 3, 6, and 7.
Scheme 3: Linear synthesis of trisaccharide derivative 2.
Scheme 4: Synthesis of ᴅ-galactose donor 12.
Scheme 5: One-pot synthesis of trisaccharide derivative 2.
Scheme 6: Synthesis of trisaccharide derivative 1.
Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol
- Lin Zhang,
- Jun Zheng,
- Guangyan Luo,
- Xiaoyue Li,
- Yunqian Zhang,
- Zhu Tao and
- Qianjun Zhang
Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194
- , Figure 1B) form via the polymerization of multiple glycoside units. The ports on both sides of these compounds are surrounded by carbonyl oxygen atoms, which form a hydrophobic cavity and two hydrophilic ports [20]. The outer surface of the cucurbit[n]uril is composed of a large number of nitrogen atoms
Graphical Abstract
Figure 1: The structures of chloramphenicol (A) and cucurbit[n]urils (B).
Figure 2: (A) CPE and Q[8] structural model diagram, (B) interaction between CPE and Q[8], (C) CPE@Q[8] stack...
Figure 3: UV–vis absorption spectra of CPE with Q[8] in aqueous solution (A) or hydrochloric acid solution (C...
Figure 4: ITC data obtained for the binding of Q[8] with CPE in an aqueous solution at 25 °C.
Figure 5: 1H NMR spectra of CPE, CPE@Q[8] and Q[8] (VD2O/VDCl = 3:2).
Figure 6: IR spectra recorded for Q[8] (a), CPE (b), a physical mixture of Q[8] and CPE (c), and the CPE@Q[8]...
Figure 7: UV absorption intensity of CPE and CPE@Q[8] changes with time in the artificial gastrointestinal ju...
Figure 8: Release curve of CPE and CPE@Q[8] in artificial gastrointestinal juice (pH 1.2, pH 6.8).
Synthetic strategies toward 1,3-oxathiolane nucleoside analogues
- Umesh P. Aher,
- Dhananjai Srivastava,
- Girij P. Singh and
- Jayashree B. S
Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182
- stereoselectivity during β-selective glycosidic bond formation. The general pathway for glycosidic bond formation (Figure 4) shows that the glycoside donor moiety has to be activated using an appropriate activator to form an oxonium ion. The attack of a nucleobase (glycosyl acceptor) may occur on either side of the
- oxonium ion, which can result in two anomers, i.e., an α- and a β-anomer. The factors affecting such stereocontrolled glycoside bond formations are also discussed in this review. The preparation of the racemate 1c was reported by Belleau et al. in 1989 (Scheme 26) [38]. The method involved the coupling of
Graphical Abstract
Figure 1: Representative modified 1,3-oxathiolane nucleoside analogues.
Figure 2: Mechanism of antiviral action of 1,3-oxathiolane nucleosides, 3TC (1) and FTC (2), as chain termina...
Figure 3: Synthetic strategies for the construction of the 1,3-oxathiolane sugar ring.
Scheme 1: Synthesis of 4 from benzoyloxyacetaldehyde (3a) and 2-mercapto-substituted dimethyl acetal 3na.
Scheme 2: Synthesis of 8 from protected glycolic aldehyde 3b and 2-mercaptoacetic acid (3o).
Scheme 3: Synthesis of 20 from ᴅ-mannose (3c).
Scheme 4: Synthesis of 20 from 1,6-thioanhydro-ᴅ-galactose (3d).
Scheme 5: Synthesis of 8 from 2-(tert-butyldiphenylsilyloxy)methyl-5-oxo-1,2-oxathiolane (3m).
Scheme 6: Synthesis of 20a from ʟ-gulose derivative 3f.
Scheme 7: Synthesis of 31 from (+)-thiolactic acid 3p and 2-benzoyloxyacetaldehyde (3a).
Scheme 8: Synthesis of 35a from 1,4-dithiane-2,5-diol (3q) and glyoxylic acid (3g) hydrate.
Scheme 9: Synthetic routes toward 41 through Pummerer reaction from methyl 2-mercaptoacetate (3j) and bromoac...
Scheme 10: Strategy for the synthesis of 2,5-substituted 1,3-oxathiolane 41a using 4-nitrobenzyl glyoxylate an...
Scheme 11: Synthesis of 44 by a resolution method using Mucor miehei lipase.
Scheme 12: Synthesis of 45 from benzoyloxyacetaldehyde (3a) and 2-mercaptoacetaldehyde bis(2-methoxyethyl) ace...
Scheme 13: Synthesis of 46 from 2-mercaptoacetaldehyde bis(2-methoxyethyl) acetal (3nc) and diethyl 3-phosphon...
Scheme 14: Synthesis of 48 from 1,3-dihydroxyacetone dimer 3l.
Scheme 15: Approach toward 52 from protected alkene 3rb and lactic acid derivative 51 developed by Snead et al....
Scheme 16: Recent approach toward 56a developed by Kashinath et al.
Scheme 17: Synthesis of 56a from ʟ-menthyl glyoxylate (3h) hydrate by DKR.
Scheme 18: Possible mechanism with catalytic TEA for rapid interconversion of isomers.
Scheme 19: Synthesis of 35a by a classical resolution method through norephedrine salt 58 formation.
Scheme 20: Synthesis of 63 via [1,2]-Brook rearrangement from silyl glyoxylate 61 and thiol 3nb.
Scheme 21: Combined use of STS and CAL-B as catalysts to synthesize an enantiopure oxathiolane precursor 65.
Scheme 22: Synthesis of 1 and 1a from glycolaldehyde dimer 64 and 1,4-dithiane-2,5-diol (3q) using STS and CAL...
Scheme 23: Synthesis of 68 by using Klebsiella oxytoca.
Scheme 24: Synthesis of 71 and 72 using Trichosporon taibachii lipase and kinetic resolution.
Scheme 25: Synthesis of 1,3-oxathiolan-5-ones 77 and 78 via dynamic covalent kinetic resolution.
Figure 4: Pathway for glycosidic bond formation.
Scheme 26: First synthesis of (±)-BCH-189 (1c) by Belleau et al.
Scheme 27: Enantioselective synthesis of 3TC (1).
Scheme 28: Synthesis of cis-diastereomer 3TC (1) from oxathiolane propionate 44.
Scheme 29: Synthesis of (±)-BCH-189 (1c) via SnCl4-mediated N-glycosylation of 8.
Scheme 30: Synthesis of (+)-BCH-189 (1a) via TMSOTf-mediated N-glycosylation of 20.
Scheme 31: Synthesis of 3TC (1) from oxathiolane precursor 20a.
Scheme 32: Synthesis of 83 via N-glycosylation of 20 with pyrimidine bases.
Scheme 33: Synthesis of 85 via N-glycosylation of 20 with purine bases.
Scheme 34: Synthesis of 86 and 87 via N-glycosylation using TMSOTf and pyrimidines.
Scheme 35: Synthesis of 90 and 91 via N-glycosylation using TMSOTf and purines.
Scheme 36: Synthesis of 3TC (1) via TMSI-mediated N-glycosylation.
Scheme 37: Stereoselective N-glycosylation for the synthesis of 1 by anchimeric assistance of a chiral auxilia...
Scheme 38: Whitehead and co-workers’ approach for the synthesis of 1 via direct N-glycosylation without an act...
Scheme 39: ZrCl4-mediated stereoselective N-glycosylation.
Scheme 40: Plausible reaction mechanism for stereoselective N-glycosylation using ZrCl4.
Scheme 41: Synthesis of enantiomerically pure oxathiolane nucleosides 1 and 2.
Scheme 42: Synthesis of tetrazole analogues of 1,3-oxathiolane nucleosides 97.
Scheme 43: Synthetic approach toward 99 from 1,3-oxathiolane 45 by Camplo et al.
Scheme 44: Synthesis of 100 from oxathiolane phosphonate analogue 46.
Scheme 45: Synthetic approach toward 102 and the corresponding cyclic thianucleoside monophosphate 102a by Cha...
Scheme 46: Synthesis of emtricitabine (2) from 1,4-dithiane-2,5-diol (3q) and glyoxylic acid (3g).
Scheme 47: Synthesis of 1 and 2, respectively, from 56a–d using iodine-mediated N-glycosylation.
Scheme 48: Plausible mechanism for silane- and I2-mediated N-glycosylation.
Scheme 49: Pyridinium triflate-mediated N-glycosylation of 35a.
Scheme 50: Possible pathway for stereoselective N-glycosylation via in situ chelation with a metal ligand.
Scheme 51: Synthesis of novel 1,3-oxathiolane nucleoside 108 from oxathiolane precursor 8 and 3-benzyloxy-2-me...
Scheme 52: Synthesis of 110 using T-705 as a nucleobase and 1,3-oxathiolane derivative 8 via N-glycosylation.
Scheme 53: Synthesis of 1 using an asymmetric leaving group and N-glycosylation with bromine and mesitylene.
Scheme 54: Cytidine deaminase for enzymatic separation of 1c.
Scheme 55: Enzymatic resolution of the monophosphate derivative 116 for the synthesis of (−)-BCH-189 (1) and (...
Scheme 56: Enantioselective resolution by PLE-mediated hydrolysis to obtain FTC (2).
Scheme 57: (+)-Menthyl chloroformate as a resolving agent to separate a racemic mixture 120.
Scheme 58: Separation of racemic mixture 1c by cocrystal 123 formation with (S)-(−)-BINOL.
Phenolic constituents from twigs of Aleurites fordii and their biological activities
- Kyoung Jin Park,
- Won Se Suh,
- Da Hye Yoon,
- Chung Sub Kim,
- Sun Yeou Kim and
- Kang Ro Lee
Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151
- of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea 10.3762/bjoc.17.151 Abstract Three new neolignan glycosides (1–3), a new phenolic glycoside (15), and a new cyanoglycoside (16) were isolated and characterized from the twigs of Aleurites fordii together with
- fordii; antineuroinflammation; Euphorbiaceae; neolignan glycoside; neuroprotective activity; phenolic compound; Introduction Aleurites fordii Hemsl. (= Vernicia fordii Hemsl., Euphorbiaceae), known as tung oil tree, is widely distributed throughout Northeast Asia [1]. The fruits, leaves, and roots of
- (1–3), a new phenolic glycoside (15), a new cyanoglucoside (16), and 14 known compounds (4–14 and 17–19) (Figure 1). Compound 1 was obtained as a colorless gum. The molecular formula was determined to be C25H32O11 from the [M + Na]+ molecular ion peak in the positive mode HRFABMS. The 1H NMR data
Graphical Abstract
Figure 1: Chemical structures of compounds 1–19.
Figure 2: Key COSY and HMBC correlations of compounds 1–3, 15, and 16 and key NOESY correlation of 2.
Progress and challenges in the synthesis of sequence controlled polysaccharides
- Giulio Fittolani,
- Theodore Tyrikos-Ergas,
- Denisa Vargová,
- Manishkumar A. Chaube and
- Martina Delbianco
Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129
- digestion. This compound was then chemically transformed to the corresponding glycosyl donors (4-methoxyphenyl- or fluoro-glycoside) to chemoenzymatically produce complex XGs. Compounds with different substitution patterns were obtained using a glycosynthase from Humicola insolens [105][106]. This approach
Graphical Abstract
Figure 1: Overview of the methods available for the synthesis of polysaccharides. For each method, advantages...
Figure 2: Overview of the classes of polysaccharides discussed in this review. Each section deals with polysa...
Scheme 1: Enzymatic and chemical polymerization approaches provide cellulose oligomers with a non-uniform dis...
Scheme 2: AGA of a collection of cellulose analogues obtained using BBs 6–9. Specifically placed modification...
Figure 3: Chemical structure of the different branches G, X, L, F commonly found in XGs. Names are given foll...
Scheme 3: AGA of XG analogues with defined side chains. The AGA cycle includes coupling (TMSOTf), Fmoc deprot...
Figure 4: Synthetic strategies and issues associated to the formation of the β(1–3) linkage.
Scheme 4: Convergent synthesis of β(1–3)-glucans using a regioselective glycosylation strategy.
Scheme 5: DMF-mediated 1,2-cis glycosylation. A) General mechanism and B) examples of α-glucans prepared usin...
Scheme 6: Synergistic glycosylation strategy employing a nucleophilic modulation strategy (TMSI and Ph3PO) in...
Scheme 7: Different approaches to produce xylans. A) Polymerization techniques including ROP, and B) enzymati...
Scheme 8: A) Synthesis of arabinofuranosyl-decorated xylan oligosaccharides using AGA. Representative compoun...
Scheme 9: Chemoenzymatic synthesis of COS utilizing a lysozyme-catalyzed transglycosylation reaction followed...
Scheme 10: Synthesis of COS using an orthogonal glycosylation strategy based on the use of two different LGs.
Scheme 11: Orthogonal N-PGs permitted the synthesis of COS with different PA.
Scheme 12: AGA of well-defined COS with different PA using two orthogonally protected BBs. The AGA cycle inclu...
Scheme 13: A) AGA of β(1–6)-N-acetylglucosamine hexasaccharide and dodecasaccharide. AGA includes cycles of co...
Figure 5: ‘Double-faced’ chemistry exemplified for ᴅ-Man and ʟ-Rha. Constructing β-Man linkages is considerab...
Figure 6: Implementation of a capping step after each glycosylation cycle for the AGA of a 50mer oligomannosi...
Scheme 14: AGA enabled the synthesis of a linear α(1–6)-mannoside 100mer 93 within 188 h and with an average s...
Scheme 15: The 151mer branched polymannoside was synthesized by a [30 + 30 + 30 + 30 + 31] fragment coupling. ...
Figure 7: PG stereocontrol strategy to obtain β-mannosides. A) The mechanism of the β-mannosylation reaction ...
Scheme 16: A) Mechanism of 1,2-cis stereoselective glycosylation using ManA donors. Once the ManA donor is act...
Figure 8: A) The preferred 4H3 conformation of the gulosyl oxocarbenium ion favors the attack of the alcohol ...
Scheme 17: AGA of type I rhamnans up to 16mer using disaccharide BB 115 and CNPiv PG. The AGA cycle includes c...
Figure 9: Key BBs for the synthesis of the O-antigen of Bacteroides vulgatus up to a 128mer (A) and the CPS o...
Figure 10: Examples of type I and type II galactans synthesized to date.
Figure 11: A) The DTBS PG stabilizes the 3H4 conformation of the Gal oxocarbenium ion favoring the attack of t...
Figure 12: Homogalacturonan oligosaccharides synthesized to date. Access to different patterns of methyl-ester...
Figure 13: GlfT2 from Mycobacterium tuberculosis catalyzes the sequential addition of UPD-Galf donor to a grow...
Figure 14: The poor reactivity of acceptor 137 hindered a stepwise synthesis of the linear galactan backbone a...
Scheme 18: AGA of a linear β(1–5) and β(1–6)-linked galactan 20mer. The AGA cycle includes coupling (NIS/TfOH)...
Figure 15: The 92mer arabinogalactan was synthesized using a [31 + 31 + 30] fragment coupling between a 31mer ...
Scheme 19: Synthesis of the branched arabinofuranose fragment using a six component one-pot synthesis. i) TTBP...
Figure 16: A) Chemical structure and SNFG of the representative disaccharide units forming the GAG backbones, ...
Figure 17: Synthetic challenges associated to the H/HS synthesis.
Scheme 20: Degradation of natural heparin and heparosan generated valuable disaccharides 150 and 151 that can ...
Scheme 21: A) The one-step conversion of cyanohydrin 156 to ʟ-iduronamide 157 represent the key step for the s...
Scheme 22: A) Chemoenzymatic synthesis of heparin structures, using different types of UDP activated natural a...
Scheme 23: Synthesis of the longest synthetic CS chain 181 (24mer) using donor 179 and acceptor 180 in an iter...
Scheme 24: AGA of a collection of HA with different lengths. The AGA cycle includes coupling (TfOH) and Lev de...
Asymmetric organocatalyzed synthesis of coumarin derivatives
- Natália M. Moreira,
- Lorena S. R. Martelli and
- Arlene G. Corrêa
Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128
- hydroquinolinone, chromene, piperidine, peptide, lipid, and glycoside moieties (Scheme 2). Bojanowski and co-workers developed a methodology to synthetize 3,4-dihydrocoumarins 10 through a decarboxylative and dearomatizative cascade reaction [33]. This reaction was carried out using coumarin-3-carboxylic acids 8
Graphical Abstract
Figure 1: Coumarin-derived commercially available drugs.
Figure 2: Inhibition of acetylcholinesterase by coumarin derivatives.
Scheme 1: Michael addition of 4-hydroxycoumarins 1 to α,β‐unsaturated enones 2.
Scheme 2: Organocatalytic conjugate addition of 4-hydroxycoumarin 1 to α,β-unsaturated aldehydes 2 followed b...
Scheme 3: Synthesis of 3,4-dihydrocoumarin derivatives 10 through decarboxylative and dearomatizative cascade...
Scheme 4: Total synthesis of (+)-smyrindiol (17).
Scheme 5: Michael addition of 4-hydroxycoumarin (1) to enones 2 through a bifunctional modified binaphthyl or...
Scheme 6: Michael addition of ketones 20 to 3-aroylcoumarins 19 using a cinchona alkaloid-derived primary ami...
Scheme 7: Enantioselective reaction of cyclopent-2-enone-derived MBH alcohols 24 with 4-hydroxycoumarins 1.
Scheme 8: Sequential Michael addition/hydroalkoxylation one-pot approach to annulated coumarins 28 and 30.
Scheme 9: Michael addition of 4-hydroxycoumarins 1 to enones 2 using a binaphthyl diamine catalyst 31.
Scheme 10: Asymmetric Michael addition of 4-hydroxycoumarin 1 with α,β-unsaturated ketones 2 catalyzed by a ch...
Scheme 11: Catalytic asymmetric β-C–H functionalization of ketones via enamine oxidation.
Scheme 12: Enantioselective synthesis of polycyclic coumarin derivatives 37 catalyzed by an primary amine-imin...
Scheme 13: Allylic alkylation reaction between 3-cyano-4-methylcoumarins 39 and MBH carbonates 40.
Scheme 14: Enantioselective synthesis of cyclopropa[c]coumarins 45.
Scheme 15: NHC-catalyzed lactonization of 2-bromoenals 46 with 4-hydroxycoumarin (1).
Scheme 16: NHC-catalyzed enantioselective synthesis of dihydrocoumarins 51.
Scheme 17: Domino reaction of enals 2 with hydroxylated malonate 53 catalyzed by NHC 55.
Scheme 18: Oxidative [4 + 2] cycloaddition of enals 57 to coumarins 56 catalyzed by NHC 59.
Scheme 19: Asymmetric [3 + 2] cycloaddition of coumarins 43 to azomethine ylides 60 organocatalyzed by quinidi...
Scheme 20: Synthesis of α-benzylaminocoumarins 64 through Mannich reaction between 4-hydroxycoumarins (1) and ...
Scheme 21: Asymmetric addition of malonic acid half-thioesters 67 to coumarins 66 using the sulphonamide organ...
Scheme 22: Enantioselective 1,4-addition of azadienes 71 to 3-homoacyl coumarins 70.
Scheme 23: Michael addition/intramolecular cyclization of 3-acylcoumarins 43 to 3-halooxindoles 74.
Scheme 24: Enantioselective synthesis of 3,4-dihydrocoumarins 78 catalyzed by squaramide 73.
Scheme 25: Organocatalyzed [4 + 2] cycloaddition between 2,4-dienals 79 and 3-coumarincarboxylates 43.
Scheme 26: Enantioselective one-pot Michael addition/intramolecular cyclization for the synthesis of spiro[dih...
Scheme 27: Michael/hemiketalization addition enantioselective of hydroxycoumarins (1) to: (a) enones 2 and (b)...
Scheme 28: Synthesis of 2,3-dihydrofurocoumarins 89 through Michael addition of 4-hydroxycoumarins 1 to β-nitr...
Scheme 29: Synthesis of pyrano[3,2-c]chromene derivatives 93 via domino reaction between 4-hydroxycoumarins (1...
Scheme 30: Conjugated addition of 4-hydroxycoumarins 1 to nitroolefins 95.
Scheme 31: Michael addition of 4-hydroxycoumarin 1 to α,β-unsaturated ketones 2 promoted by primary amine thio...
Scheme 32: Enantioselective synthesis of functionalized pyranocoumarins 99.
Scheme 33: 3-Homoacylcoumarin 70 as 1,3-dipole for enantioselective concerted [3 + 2] cycloaddition.
Scheme 34: Synthesis of warfarin derivatives 107 through addition of 4-hydroxycoumarins 1 to β,γ-unsaturated α...
Scheme 35: Asymmetric multicatalytic reaction sequence of 2-hydroxycinnamaldehydes 109 with 4-hydroxycoumarins ...
Scheme 36: Mannich asymmetric addition of cyanocoumarins 39 to isatin imines 112 catalyzed by the amide-phosph...
Scheme 37: Enantioselective total synthesis of (+)-scuteflorin A (119).
On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets
- Renato L. Carvalho,
- Amanda S. de Miranda,
- Mateus P. Nunes,
- Roberto S. Gomes,
- Guilherme A. M. Jardim and
- Eufrânio N. da Silva Júnior
Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126
Graphical Abstract
Scheme 1: Schematic overview of transition metals studied in C–H activation processes.
Scheme 2: (A) Known biological activities related to benzimidazole-based compounds; (B and C) an example of a...
Scheme 3: (A) Known biological activities related to quinoline-based compounds; (B and C) an example of a sca...
Scheme 4: (A) Known biological activities related to sulfur-containing compounds; (B and C) an example of a s...
Scheme 5: (A) Known biological activities related to aminoindane derivatives; (B and C) an example of a scand...
Scheme 6: (A) Known biological activities related to norbornane derivatives; (B and C) an example of a scandi...
Scheme 7: (A) Known biological activities related to aniline derivatives; (B and C) an example of a titanium-...
Scheme 8: (A) Known biological activities related to cyclohexylamine derivatives; (B) an example of an intram...
Scheme 9: (A) Known biologically active benzophenone derivatives; (B and C) photocatalytic oxidation of benzy...
Scheme 10: (A) Known bioactive fluorine-containing compounds; (B and C) vanadium-mediated C(sp3)–H fluorinatio...
Scheme 11: (A) Known biologically active Lythraceae alkaloids; (B) synthesis of (±)-decinine (30).
Scheme 12: (A) Synthesis of (R)- and (S)-boehmeriasin (31); (B) synthesis of phenanthroindolizidines by vanadi...
Scheme 13: (A) Known bioactive BINOL derivatives; (B and C) vanadium-mediated oxidative coupling of 2-naphthol...
Scheme 14: (A) Known antiplasmodial imidazopyridazines; (B) practical synthesis of 41.
Scheme 15: (A) Gold-catalyzed drug-release mechanism using 2-alkynylbenzamides; (B and C) chromium-mediated al...
Scheme 16: (A) Examples of anti-inflammatory benzaldehyde derivatives; (B and C) chromium-mediated difunctiona...
Scheme 17: (A and B) Manganese-catalyzed chemoselective intramolecular C(sp3)–H amination; (C) late-stage modi...
Scheme 18: (A and B) Manganese-catalyzed C(sp3)–H amination; (C) late-stage modification of a leelamine deriva...
Scheme 19: (A) Known bioactive compounds containing substituted N-heterocycles; (B and C) manganese-catalyzed ...
Scheme 20: (A) Known indoles that present GPR40 full agonist activity; (B and C) manganese-catalyzed C–H alkyl...
Scheme 21: (A) Examples of known biaryl-containing drugs; (B and C) manganese-catalyzed C–H arylation through ...
Scheme 22: (A) Known zidovudine derivatives with potent anti-HIV properties; (B and C) manganese-catalyzed C–H...
Scheme 23: (A and B) Manganese-catalyzed C–H organic photo-electrosynthesis; (C) late-stage modification.
Scheme 24: (A) Example of a known antibacterial silylated dendrimer; (B and C) manganese-catalyzed C–H silylat...
Scheme 25: (A and B) Fe-based small molecule catalyst applied for selective aliphatic C–H oxidations; (C) late...
Scheme 26: (A) Examples of naturally occurring gracilioethers; (B) the first total synthesis of gracilioether ...
Scheme 27: (A and B) Selective aliphatic C–H oxidation of amino acids; (C) late-stage modification of proline-...
Scheme 28: (A) Examples of Illicium sesquiterpenes; (B) first chemical synthesis of (+)-pseudoanisatin (80) in...
Scheme 29: (A and B) Fe-catalyzed deuteration; (C) late-stage modification of pharmaceuticals.
Scheme 30: (A and B) Biomimetic Fe-catalyzed aerobic oxidation of methylarenes to benzaldehydes (PMHS, polymet...
Scheme 31: (A) Known tetrahydroquinolines with potential biological activities; (B and C) redox-selective Fe c...
Scheme 32: (A) Known drugs containing a benzofuran unit; (B and C) Fe/Cu-catalyzed tandem O-arylation to acces...
Scheme 33: (A) Known azaindolines that act as M4 muscarinic acetylcholine receptor agonists; (B and C) intramo...
Scheme 34: (A) Known indolinones with anticholinesterase activity; (B and C) oxidative C(sp3)–H cross coupling...
Scheme 35: (A and B) Cobalt-catalyzed C–H alkenylation of C-3-peptide-containing indoles; (C) derivatization b...
Scheme 36: (A) Cobalt-Cp*-catalyzed C–H methylation of known drugs; (B and C) scope of the o-methylated deriva...
Scheme 37: (A) Known lasalocid A analogues; (B and C) three-component cobalt-catalyzed C–H bond addition; (D) ...
Scheme 38: (A and B) Cobalt-catalyzed C(sp2)–H amidation of thiostrepton.
Scheme 39: (A) Known 4H-benzo[d][1,3]oxazin-4-one derivatives with hypolipidemic activity; (B and C) cobalt-ca...
Scheme 40: (A and B) Cobalt-catalyzed C–H arylation of pyrrole derivatives; (C) application for the synthesis ...
Scheme 41: (A) Known 2-phenoxypyridine derivatives with potent herbicidal activity; (B and C) cobalt-catalyzed...
Scheme 42: (A) Natural cinnamic acid derivatives; (B and C) cobalt-catalyzed C–H carboxylation of terminal alk...
Scheme 43: (A and B) Cobalt-catalyzed C–H borylation; (C) application to the synthesis of flurbiprofen.
Scheme 44: (A) Benzothiazoles known to present anticonvulsant activities; (B and C) cobalt/ruthenium-catalyzed...
Scheme 45: (A and B) Cobalt-catalyzed oxygenation of methylene groups towards ketone synthesis; (C) synthesis ...
Scheme 46: (A) Known anticancer tetralone derivatives; (B and C) cobalt-catalyzed C–H difluoroalkylation of ar...
Scheme 47: (A and B) Cobalt-catalyzed C–H thiolation; (C) application in the synthesis of quetiapine (153).
Scheme 48: (A) Known benzoxazole derivatives with anticancer, antifungal, and antibacterial activities; (B and...
Scheme 49: (A and B) Cobalt-catalyzed C–H carbonylation of naphthylamides; (C) BET inhibitors 158 and 159 tota...
Scheme 50: (A) Known bioactive pyrrolo[1,2-a]quinoxalin-4(5H)-one derivatives; (B and C) cobalt-catalyzed C–H ...
Scheme 51: (A) Known antibacterial cyclic sulfonamides; (B and C) cobalt-catalyzed C–H amination of propargyli...
Scheme 52: (A and B) Cobalt-catalyzed intramolecular 1,5-C(sp3)–H amination; (C) late-stage functionalization ...
Scheme 53: (A and B) Cobalt-catalyzed C–H/C–H cross-coupling between benzamides and oximes; (C) late-state syn...
Scheme 54: (A) Known anticancer natural isoquinoline derivatives; (B and C) cobalt-catalyzed C(sp2)–H annulati...
Scheme 55: (A) Enantioselective intramolecular nickel-catalyzed C–H activation; (B) bioactive obtained motifs;...
Scheme 56: (A and B) Nickel-catalyzed α-C(sp3)–H arylation of ketones; (C) application of the method using kno...
Scheme 57: (A and B) Nickel-catalyzed C(sp3)–H acylation of pyrrolidine derivatives; (C) exploring the use of ...
Scheme 58: (A) Nickel-catalyzed C(sp3)–H arylation of dioxolane; (B) library of products obtained from biologi...
Scheme 59: (A) Intramolecular enantioselective nickel-catalyzed C–H cycloalkylation; (B) product examples, inc...
Scheme 60: (A and B) Nickel-catalyzed C–H deoxy-arylation of azole derivatives; (C) late-stage functionalizati...
Scheme 61: (A and B) Nickel-catalyzed decarbonylative C–H arylation of azole derivatives; (C) application of t...
Scheme 62: (A and B) Another important example of nickel-catalyzed C–H arylation of azole derivatives; (C) app...
Scheme 63: (A and B) Another notable example of a nickel-catalyzed C–H arylation of azole derivatives; (C) lat...
Scheme 64: (A and B) Nickel-based metalorganic framework (MOF-74-Ni)-catalyzed C–H arylation of azole derivati...
Scheme 65: (A) Known commercially available benzothiophene-based drugs; (B and C) nickel-catalyzed C–H arylati...
Scheme 66: (A) Known natural tetrahydrofuran-containing substances; (B and C) nickel-catalyzed photoredox C(sp3...
Scheme 67: (A and B) Another notable example of a nickel-catalyzed photoredox C(sp3)–H alkylation/arylation; (...
Scheme 68: (A) Electrochemical/nickel-catalyzed C–H alkoxylation; (B) achieved scope, including three using na...
Scheme 69: (A) Enantioselective photoredox/nickel catalyzed C(sp3)–H arylation; (B) achieved scope, including ...
Scheme 70: (A) Known commercially available trifluoromethylated drugs; (B and C) nickel-catalyzed C–H trifluor...
Scheme 71: (A and B) Stereoselective nickel-catalyzed C–H difluoroalkylation; (C) late-stage functionalization...
Scheme 72: (A) Cu-mediated ortho-amination of oxalamides; (B) achieved scope, including derivatives obtained f...
Scheme 73: (A) Electro-oxidative copper-mediated amination of 8-aminoquinoline-derived amides; (B) achieved sc...
Scheme 74: (A and B) Cu(I)-mediated C–H amination with oximes; (C) derivatization using telmisartan (241) as s...
Scheme 75: (A and B) Cu-mediated amination of aryl amides using ammonia; (C) late-stage modification of proben...
Scheme 76: (A and B) Synthesis of purine nucleoside analogues using copper-mediated C(sp2)–H activation.
Scheme 77: (A) Copper-mediated annulation of acrylamide; (B) achieved scope, including the synthesis of the co...
Scheme 78: (A) Known bioactive compounds containing a naphthyl aryl ether motif; (B and C) copper-mediated eth...
Scheme 79: (A and B) Cu-mediated alkylation of N-oxide-heteroarenes; (C) late-stage modification.
Scheme 80: (A) Cu-mediated cross-dehydrogenative coupling of polyfluoroarenes and alkanes; (B) scope from know...
Scheme 81: (A) Known anticancer acrylonitrile compounds; (B and C) Copper-mediated cyanation of unactivated al...
Scheme 82: (A) Cu-mediated radiofluorination of 8-aminoquinoline-derived aryl amides; (B) achieved scope, incl...
Scheme 83: (A) Examples of natural β-carbolines; (B and C) an example of a zinc-catalyzed C–H functionalizatio...
Scheme 84: (A) Examples of anticancer α-aminophosphonic acid derivatives; (B and C) an example of a zinc-catal...
Chemical synthesis of C6-tetrazole ᴅ-mannose building blocks and access to a bioisostere of mannuronic acid 1-phosphate
- Eleni Dimitriou and
- Gavin J. Miller
Beilstein J. Org. Chem. 2021, 17, 1527–1532, doi:10.3762/bjoc.17.110
- overall yield for the route increased from 9 to 21%. To demonstrate capability for anomeric linker attachment and conversion to a biologically relevant analogue of mannuronic acid 1-phosphate, 3-aminopropyl glycoside 20 and glycosyl 1-phosphate 21 were synthesised (Scheme 4). The mixture 18/19 was used
Graphical Abstract
Figure 1: a) Chemical structure of alginate showing constituent M and G residues and C2/C3 acetylation for on...
Scheme 1: a) H2N(CH2)2CN, PyBOP, DIPEA, CH2Cl2, 0 °C, 40 min, 47% (+44% 3); b) TBSOTf, imidazole, DMAP, DMF, ...
Scheme 2: a) BzCl, DMAP, pyridine, CH2Cl2, rt, 24 h, 90%; b) TBSOTf, imidazole, DMAP, DMF, 40 °C, 24 h, 78%; ...
Scheme 3: a) PMBCl, KI, K2CO3, DMF, rt, 53% for 11 and 12; b) BnBr, DMF, Et3N, DCM, rt, 31% for 13 and 14.
Scheme 4: a) DMSO, SO3·pyridine, Et3N, rt, 1 h, 96%; b) H2NOH·HCl, THF, H2O, Na2CO3, 89%; c) POCl3, MeCN, 65 ...
Metal-free glycosylation with glycosyl fluorides in liquid SO2
- Krista Gulbe,
- Jevgeņija Lugiņina,
- Edijs Jansons,
- Artis Kinens and
- Māris Turks
Beilstein J. Org. Chem. 2021, 17, 964–976, doi:10.3762/bjoc.17.78
- dioxide was deactivated (Table 2, entries 2 and 5), while in less polar solvents (toluene, DCM) the presence of sulfur dioxide was clearly advantageous and glycoside 3a was isolated in good yields (Table 2, entries 7 and 10). Next, the reactivity of various mannosyl halides α-1a–c towards O- and S
- cyclobutanol (2s) that further reacts with the glycosyl donor. Additionally, our glycosylation approach in liquid SO2 was applied for the synthesis of C-glycoside 3q by employing electron-rich 1,2,3-trimethoxybenzene (2q). Also binucleophiles 7a and 7b were glycosylated with a slight excess of mannosyl
Graphical Abstract
Scheme 1: Scope of glycosyl acceptors for glycosylation with pivaloyl-protected mannosyl fluoride α-1a in liq...
Scheme 2: Glycosylation of binucleophiles 7a,b in liquid SO2.
Scheme 3: Pivaloyl-protected glucosyl fluoride β-9 as a glycosyl donor in liquid SO2.
Scheme 4: Benzyl protected manno- and glucopyranosyl fluorides α-15 and 16 as glycosyl donors in liquid SO2. ...
Scheme 5: 2-Deoxy glycosyl fluoride α-19 as a glycosyl donor in liquid SO2.
Figure 1: Detection of the FSO2− species by 19F NMR (471 MHz, D2O).
Figure 2: Computational study of reaction mechanism α-11 + MeOH → α-13c in the presence of and in absence of ...
Regioselective chemoenzymatic syntheses of ferulate conjugates as chromogenic substrates for feruloyl esterases
- Olga Gherbovet,
- Fernando Ferreira,
- Apolline Clément,
- Mélanie Ragon,
- Julien Durand,
- Sophie Bozonnet,
- Michael J. O'Donohue and
- Régis Fauré
Beilstein J. Org. Chem. 2021, 17, 325–333, doi:10.3762/bjoc.17.30
- groups of the glycoside and the O-acetyl group of the ferulate moiety. The fact that lipase-catalyzed transesterification obviates the need for protection and deprotection is a considerable advantage because the final deprotection in the chemical pathway is complicated by the presence of another ester
Graphical Abstract
Figure 1: Alternative syntheses (A) and full structures (B) of the 5-bromo-4-chloro-3-indolyl or 4-nitropheny...
Scheme 1: Chemoenzymatic synthesis of (±)-4-O-(2-hydroxy-4-nitrophenyl)-1-O-trans-feruloyl-1,2,4-butanetriol ...
Figure 2: (A) Spectrometric monitoring (at 530 nm) of 4NTC released after the action of Fae on 12 in the pres...
Chemical constituents of Chaenomeles sinensis twigs and their biological activity
- Joon Min Cha,
- Dong Hyun Kim,
- Lalita Subedi,
- Zahra Khan,
- Sang Un Choi,
- Sun Yeou Kim and
- Chung Sub Kim
Beilstein J. Org. Chem. 2020, 16, 3078–3085, doi:10.3762/bjoc.16.257
- Chemical Technology, Daejeon 34114, Republic of Korea Gachon Institute of Pharmaceutical Science, Gachon University, Incheon 21936, Republic of Korea 10.3762/bjoc.16.257 Abstract A new megastigmane-type norsesquiterpenoid glycoside, chaemeloside (1), was isolated from the twigs of Chaenomeles sinensis
- a new megastigmane-type norsesquiterpenoid glycoside 1 along with 11 known compounds (2–12, Figure 1). The structure of the new compound 1 was established on the basis of spectroscopic and spectrometric data analysis, and chiral derivatization coupled with NMR or LC–MS experiments. All isolated
- compounds, only compound 8 (apigenin) exhibited a weak activity on the NGF release with a stimulation level of 127.8 ± 2.0% without displaying cell toxicity (100.9 ± 0.6%). Conclusion A new megastigmane-type norsesquiterpenoid glycoside 1 was isolated along with 11 known compounds from the MeOH extract of C
Graphical Abstract
Figure 1: Chemical structures of compounds 1–13.
Figure 2: Structure elucidation of compound 1. (A) Key COSY (blue bold) and HMBC (red arrows) correlations of ...
Anion exchange resins in phosphate form as versatile carriers for the reactions catalyzed by nucleoside phosphorylases
- Julia N. Artsemyeva,
- Ekaterina A. Remeeva,
- Tatiana N. Buravskaya,
- Irina D. Konstantinova,
- Roman S. Esipov,
- Anatoly I. Miroshnikov,
- Natalia M. Litvinko and
- Igor A. Mikhailopulo
Beilstein J. Org. Chem. 2020, 16, 2607–2622, doi:10.3762/bjoc.16.212
- increased the time required for the complete breakdown of the glycoside bond of the starting nucleoside. In order to find optimal conditions for the phosphorolysis reaction in the presence of Dowex-nPi, we analyzed some of the results of previous studies in terms of the role of the amount of bioсatalyst
Graphical Abstract
Scheme 1: General scheme of the suggested synthesis of nucleosides employing the enzymatic phosphorolysis of ...
Figure 1: Phosphorolysis (5.0 mM K-phosphate buffer, pH 7.0; 23 °C) of Ara-U and thymidine (Thd) catalyzed by...
Scheme 2: Transarabinosylation of O6-methylguanine (OMG) employing Ara-U as a donor of the Ara-1Pi (1:1.5 mol...
Figure 2: Optimized conditions of phosphorolysis of Ara-U: 0.20 mmol of Ara-U in distilled water (30 mL) cont...
Scheme 3: Synthesis of nelarabine with intermediate preparation of crude Ara-1Pi.
Scheme 4: Synthesis of kinetin riboside with intermediate preparation of crude Rib-1Pi.
Recent synthesis of thietanes
- Jiaxi Xu
Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116
Graphical Abstract
Figure 1: Examples of biologically active thietane-containing molecules.
Figure 2: The diverse methods for the synthesis of thietanes.
Scheme 1: Synthesis of 1-(thietan-2-yl)ethan-1-ol (10) from 3,5-dichloropentan-2-ol (9).
Scheme 2: Synthesis of thietanose nucleosides 2,14 from 2,2-bis(bromomethyl)propane-1,3-diol (11).
Scheme 3: Synthesis of methyl 3-vinylthietane-3-carboxylate (19).
Scheme 4: Synthesis of 1,6-thiazaspiro[3.3]heptane (24).
Scheme 5: Synthesis of 6-amino-2-thiaspiro[3.3]heptane hydrochloride (28).
Scheme 6: Synthesis of optically active thietane 31 from vitamin C.
Scheme 7: Synthesis of an optically active thietane nucleoside from diethyl L-tartrate (32).
Scheme 8: Synthesis of thietane-containing spironucleoside 40 from 5-aldo-3-O-benzyl-1,2-O-isopropylidene-α-D...
Scheme 9: Synthesis of optically active 2-methylthietane-containing spironucleoside 43.
Scheme 10: Synthesis of a double-linked thietane-containing spironucleoside 48.
Scheme 11: Synthesis of two diastereomeric thietanose nucleosides via 2,4-di(benzyloxymethyl)thietane (49).
Scheme 12: Synthesis of the thietane-containing PI3k inhibitor candidate 54.
Scheme 13: Synthesis of the spirothietane 57 as the key intermediate to Nuphar sesquiterpene thioalkaloids.
Scheme 14: Synthesis of spirothietane 61 through a direct cyclic thioetherification of 3-mercaptopropan-1-ol.
Scheme 15: Synthesis of thietanes 66 from 1,3-diols 62.
Scheme 16: Synthesis of thietanylbenzimidazolone 75 from (iodomethyl)thiazolobenzimidazole 70.
Scheme 17: Synthesis of 2-oxa-6-thiaspiro[3.3]heptane (80) from bis(chloromethyl)oxetane 76 and thiourea.
Scheme 18: Synthesis of the thietane-containing glycoside, 2-O-p-toluenesulfonyl-4,6-thioanhydro-α-D-gulopyran...
Scheme 19: Synthesis of methyl 4,6-thioanhydro-α-D-glucopyranoside (89).
Scheme 20: Synthesis of thietane-fused α-D-galactopyranoside 93.
Scheme 21: Synthesis of thietane-fused α-D-gulopyranoside 100.
Scheme 22: Synthesis of 3,5-anhydro-3-thiopentofuranosides 104.
Scheme 23: Synthesis of anhydro-thiohexofuranosides 110, 112 and 113 from from 1,2:4,5-di-O-isopropylidene D-f...
Scheme 24: Synthesis of optically active thietanose nucleosides from D- and L-xyloses.
Scheme 25: Synthesis of thietane-fused nucleosides.
Scheme 26: Synthesis of 3,5-anhydro-3-thiopentofuranosides.
Scheme 27: Synthesis of 2-amino-3,5-anhydro-3-thiofuranoside 141.
Scheme 28: Synthesis of thietane-3-ols 145 from (1-chloromethyl)oxiranes 142 and hydrogen sulfide.
Scheme 29: Synthesis of thietane-3-ol 145a from chloromethyloxirane (142a).
Scheme 30: Synthesis of thietane-3-ols 145 from 2-(1-haloalkyl)oxiranes 142 and 147 with ammonium monothiocarb...
Scheme 31: Synthesis of 7-deoxy-5(20)thiapaclitaxel 154a, a thietane derivative of taxoids.
Scheme 32: Synthesis of 5(20)-thiadocetaxel 158 from 10-deacetylbaccatin III (155).
Scheme 33: Synthesis of thietane derivatives 162 as precursors for deoxythiataxoid synthesis through oxiraneme...
Scheme 34: Synthesis of 7-deoxy 5(20)-thiadocetaxel 154b.
Scheme 35: Mechanism for the formation of the thietane ring in 171 from oxiranes with vicinal leaving groups 1...
Scheme 36: Synthesis of cis-2,3-disubstituted thietane 175 from thiirane-2-methanol 172.
Scheme 37: Synthesis of a bridged thietane 183 from aziridine cyclohexyl tosylate 179 and ammonium tetrathiomo...
Scheme 38: Synthesis of thietanes via the photochemical [2 + 2] cycloaddition of thiobenzophenone 184a with va...
Scheme 39: Synthesis of spirothietanes through the photo [2 + 2] cycloaddition of cyclic thiocarbonyls with ol...
Scheme 40: Photochemical synthesis of spirothietane-thioxanthenes 210 from thioxanthenethione (208) and butatr...
Scheme 41: Synthesis of thietanes 213 from 2,4,6-tri(tert-butyl)thiobenzaldehyde (211) with substituted allene...
Scheme 42: Photochemical synthesis of spirothietanes 216 and 217 from N-methylthiophthalimide (214) with olefi...
Scheme 43: Synthesis of fused thietanes from quadricyclane with thiocarbonyl derivatives 219.
Scheme 44: Synthesis of tricyclic thietanes via the photo [2 + 2] cycloaddition of N-methyldithiosuccinimides ...
Scheme 45: Synthesis of tricyclic thietanes via the photo [2 + 2] cycloaddition of N-methylthiosuccinimide/thi...
Scheme 46: Synthesis of tricyclic thietanes via the photo [2 + 2] cycloaddition of N-alkylmonothiophthalimides...
Scheme 47: Synthesis of spirothietanes from dithiosuccinimides 223 with 2,3-dimethyl-2-butene (215a).
Scheme 48: Synthesis of thietanes 248a,b from diaryl thione 184b and ketene acetals 247a,b.
Scheme 49: Photocycloadditions of acridine-9-thiones 249 and pyridine-4(1H)-thione (250) with 2-methylacrynitr...
Scheme 50: Synthesis of thietanes via the photo [2 + 2] cycloaddition of mono-, di-, and trithiobarbiturates 2...
Scheme 51: Synthesis of spirothietanes via the photo [2 + 2] cycloaddition of 1,1,3-trimethyl-2-thioxo-1,2-dih...
Scheme 52: Synthesis of spirothietanes via the photo [2 + 2] cycloaddition of thiocoumarin 286 with olefins.
Scheme 53: Photochemical synthesis of thietanes 296–299 from semicyclic and acyclic thioimides 292–295 and 2,3...
Scheme 54: Photochemical synthesis of spirothietane 301 from 1,3,3-trimethylindoline-2-thione (300) and isobut...
Scheme 55: Synthesis of spirobenzoxazolethietanes 303 via the photo [2 + 2] cycloaddition of alkyl and aryl 2-...
Scheme 56: Synthesis of spirothietanes from tetrahydrothioxoisoquinolines 306 and 307 with olefins.
Scheme 57: Synthesis of spirothietanes from 1,3-dihydroisobenzofuran-1-thiones 311 and benzothiophene-1-thione...
Scheme 58: Synthesis of 2-triphenylsilylthietanes from phenyl triphenylsilyl thioketone (316) with electron-po...
Scheme 59: Diastereoselective synthesis of spiropyrrolidinonethietanes 320 via the photo [2 + 2] cycloaddition...
Scheme 60: Synthesis of bicyclic thietane 323 via the photo [2 + 2] cycloaddition of 2,4-dioxo-3,4-dihydropyri...
Scheme 61: Photo-induced synthesis of fused thietane-2-thiones 325 and 326 from silacyclopentadiene 324 and ca...
Scheme 62: Synthesis of highly strained tricyclic thietanes 328 via the intramolecular photo [2 + 2] cycloaddi...
Scheme 63: Synthesis of tri- and pentacyclic thietanes 330 and 332, respectively, through the intramolecular p...
Scheme 64: Synthesis of tricyclic thietanes 334 via the intramolecular photo [2 + 2] cycloaddition of N-vinylt...
Scheme 65: Synthesis of tricyclic thietanes 336 via the intramolecular photo [2 + 2] cycloaddition of N-but-3-...
Scheme 66: Synthesis of tricyclic thietanes via the intramolecular photo [2 + 2] cycloaddition of N-but-3-enyl...
Scheme 67: Synthesis of tetracyclic thietane 344 through the intramolecular photo [2 + 2] cycloaddition of N-[...
Scheme 68: Synthesis of tri- and tetracyclic thietanes 348, 350, and 351, through the intramolecular photo [2 ...
Scheme 69: Synthesis of tetracyclic fused thietane 354 via the photo [2 + 2] cycloaddition of vinyl 2-thioxo-3H...
Scheme 70: Synthesis of highly rigid thietane-fused β-lactams via the intramolecular photo [2 + 2] cycloadditi...
Scheme 71: Asymmetric synthesis of a highly rigid thietane-fused β-lactam 356a via the intramolecular photo [2...
Scheme 72: Diastereoselective synthesis of the thietane-fused β-lactams via the intramolecular photo [2 + 2] c...
Scheme 73: Asymmetric synthesis of thietane-fused β-lactams 356 via the intramolecular photo [2 + 2] cycloaddi...
Scheme 74: Synthesis of the bridged bis(trifluoromethyl)thietane from 2,2,4,4-tetrakis(trifluoromethyl)-1,3-di...
Scheme 75: Synthesis of the bridged-difluorothietane 368 from 2,2,4,4-tetrafluoro-1,3-dithietane (367) and qua...
Scheme 76: Synthesis of bis(trifluoromethyl)thietanes from 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithietane (3...
Scheme 77: Synthesis of 2,2-dimethylthio-4,4-di(trifluoromethyl)thietane (378) from 2,2,4,4-tetrakis(trifluoro...
Scheme 78: Formation of bis(trifluoromethyl)thioacetone (381) through nucleophilic attack of dithietane 363 by...
Scheme 79: Synthesis of 2,2-bis(trifluoromethyl)thietanes from 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithietan...
Scheme 80: Synthesis of the bridged bis(trifluoromethyl)thietane 364 from of 2,2,4,4-tetrakis(trifluoromethyl)...
Scheme 81: Synthesis of 2,4-diiminothietanes 390 from alkenimines and 4-methylbenzenesulfonyl isothiocyanate (...
Scheme 82: Synthesis of arylidene 2,4-diiminothietanes 393 starting from phosphonium ylides 391 and isothiocya...
Scheme 83: Synthesis of thietane-2-ylideneacetates 397 through a DABCO-catalyzed formal [2 + 2] cycloaddition ...
Scheme 84: Synthesis of 3-substituted thietanes 400 from (1-chloroalkyl)thiiranes 398.
Scheme 85: Synthesis of N-(thietane-3-yl)azaheterocycles 403 and 404 through reaction of chloromethylthiirane (...
Scheme 86: Synthesis of 3-sulfonamidothietanes 406 from sulfonamides and chloromethylthiirane (398a).
Scheme 87: Synthesis of N-(thietane-3-yl)isatins 408 from chloromethylthiirane (398a) and isatins 407.
Scheme 88: Synthesis of 3-(nitrophenyloxy)thietanes 410 from nitrophenols 409 and chloromethylthiirane (398a).
Scheme 89: Synthesis of N-aryl-N-(thietane-3-yl)cyanamides 412 from N-arylcyanamides 411 and chloromethylthiir...
Scheme 90: Synthesis of 1-(thietane-3-yl)pyrimidin-2,4(1H,3H)-diones 414 from chloromethylthiirane (398a) and ...
Scheme 91: Synthesis of 2,4-diiminothietanes 418 from 2-iminothiiranes 416 and isocyanoalkanes 415.
Scheme 92: Synthesis of 2-vinylthietanes 421 from thiiranes 419 and 3-chloroallyl lithium (420).
Scheme 93: Synthesis of thietanes from thiiranes 419 and trimethyloxosulfonium iodide 424.
Scheme 94: Mechanism for synthesis of thietanes 425 from thiiranes 419 and trimethyloxosulfonium iodide 424.
Scheme 95: Synthesis of functionalized thietanes from thiiranes and dimethylsulfonium acylmethylides.
Scheme 96: Mechanism for the rhodium-catalyzed synthesis of functionalized thietanes 429 from thiiranes 419 an...
Scheme 97: Synthesis of 3-iminothietanes 440 through thermal isomerization from 4,5-dihydro-1,3-oxazole-4-spir...
Scheme 98: Synthesis of thietanes 443 from 3-chloro-2-methylthiolane (441) through ring contraction.
Scheme 99: Synthesis of an optically active thietanose 447 from D-xylose involving a ring contraction.
Scheme 100: Synthesis of optically thietane 447 via the DAST-mediated ring contraction of 448.
Scheme 101: Synthesis of the optically thietane nucleoside 451 via the ring contraction of thiopentose in 450.
Scheme 102: Synthesis of spirothietane 456 from 3,3,5,5-tetramethylthiolane-2,4-dithione (452) and benzyne (453...
Scheme 103: Synthesis of thietanes 461 via photoisomerization of 2H,6H-thiin-3-ones 459.
Scheme 104: Phosphorodithioate-mediated synthesis of 1,4-diarylthietanes 465.
Scheme 105: Mechanism of the phosphorodithioate-mediated synthesis of 1,4-diarylthietanes 465.
Scheme 106: Phosphorodithioate-mediated synthesis of trisubstituted thietanes (±)-470.
Scheme 107: Mechanism on the phosphorodithioate-mediated synthesis of trisubstituted thietanes.
Scheme 108: Phosphorodithioate-mediated synthesis of thietanes (±)-475.
Scheme 109: Phosphorodithioate-mediated synthesis of 1,2-disubstituted thietanes from aldehydes 476 and acrylon...
Scheme 110: Phosphorodithioate-mediated synthesis of 1,2-disubstituted thietanes via a one-pot three-component ...
Scheme 111: Mechanism for the phosphorodithioate-mediated synthesis of 1,2-disubstituted thietanes via three-co...
Scheme 112: Phosphorodithioate-mediated synthesis of substituted 3-nitrothietanes.
Scheme 113: Mechanism on the phosphorodithioate-mediated synthesis of 1,2-disubstituted thietanes (±)-486.
Scheme 114: Asymmetric synthesis of (S)-2-phenylthietane (497).
Scheme 115: Asymmetric synthesis of optically active 2,4-diarylthietanes.
Scheme 116: Synthesis of 3-acetamidothietan-2-one 503 via the intramolecular thioesterification of 3-mercaptoal...
Scheme 117: Synthesis of 4-substituted thietan-2-one via the intramolecular thioesterification of 3-mercaptoalk...
Scheme 118: Synthesis of 4,4-disubstituted thietan-2-one 511 via the intramolecular thioesterification of the 3...
Scheme 119: Synthesis of a spirothietan-2-one 514 via the intramolecular thioesterification of 3-mercaptoalkano...
Scheme 120: Synthesis of thiatetrahydrolipstatin starting from (S)-(−)-epichlorohydrin ((S)-142a).
Scheme 121: Synthesis of 2-phenethyl-4-(propan-2-ylidene)thietane (520) from 5-bromo-6-methyl-1-phenylhept-5-en...
Scheme 122: Synthesis of 2-phenethyl-4-(propan-2-ylidene)thietane (520) directly from S-(5-bromo-6-methyl-1-phe...
Scheme 123: Synthesis of 2-alkylidenethietanes from S-(2-bromoalk-1-en-4-yl)thioacetates.
Scheme 124: Synthesis of 2-alkylidenethietanes from S-(2-bromo/chloroalk-1-en-4-yl)thiols.
Scheme 125: Synthesis of spirothietan-3-ol 548 from enone 545 and ammonium hydrosulfide.
Scheme 126: Asymmetric synthesis of the optically active thietanoside from cis-but-2-ene-1,4-diol (47).
Scheme 127: Synthesis of 2-alkylidenethietan-3-ols 557 via the fluoride-mediated cyclization of thioacylsilanes ...
Scheme 128: Synthesis of 2-iminothietanes via the reaction of propargylbenzene (558) and isothiocyanates 560 in...
Scheme 129: Synthesis of 2-benzylidenethietane 567 via the nickel complex-catalyzed electroreductive cyclizatio...
Scheme 130: Synthesis of 2-iminothietanes 569 via the photo-assisted electrocyclic reaction of N-monosubstitute...
Scheme 131: Synthesis of ethyl 3,4-diiminothietane-2-carboxylates from ethyl thioglycolate (570) and bis(imidoy...
Scheme 132: Synthesis of N-(thietan-3-yl)-α-oxoazaheterocycles from azaheterocyclethiones and chloromethyloxira...
Scheme 133: Synthesis of thietan-3-yl benzoate (590) via the nickel-catalyzed intramolecular reductive thiolati...
Scheme 134: Synthesis of 2,2-bis(trifluoromethyl)thietane from 3,3-bis(trifluoromethyl)-1,2-dithiolane.
Scheme 135: Synthesis of thietanes from enamines and sulfonyl chlorides.
Scheme 136: Synthesis of spirothietane 603 via the [2 + 3] cycloaddition of 2,2,4,4-tetramethylcyclobutane-1,3-...
Scheme 137: Synthesis of thietane (605) from 1-bromo-3-chloropropane and sulfur.
Oxime radicals: generation, properties and application in organic synthesis
- Igor B. Krylov,
- Stanislav A. Paveliev,
- Alexander S. Budnikov and
- Alexander O. Terent’ev
Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107
Graphical Abstract
Figure 1: Imine-N-oxyl radicals (IV) discussed in the present review and other classes of N-oxyl radicals (I–...
Figure 2: The products of decomposition of iminoxyl radicals generated from oximes by oxidation with Ag2O.
Scheme 1: Generation of oxime radicals and study of the kinetics of their decay by photolysis of the solution...
Scheme 2: Synthesis of di-tert-butyliminoxyl radical and its decomposition products.
Scheme 3: The proposed reaction pathway of the decomposition of di-tert-butyliminoxyl radical (experimentally...
Scheme 4: Monomolecular decomposition of the tert-butyl(triethylmethyl)oxime radical.
Scheme 5: The synthesis and stability of the most stable dialkyl oxime radicals – di-tert-butyliminoxyl and d...
Scheme 6: The formation of iminoxyl radicals from β-diketones under the action of NO2.
Scheme 7: Synthesis of the diacetyliminoxyl radical.
Scheme 8: Examples of long-living oxime radicals with electron-withdrawing groups and the conditions for thei...
Figure 3: The electronic structure iminoxyl radicals and their geometry compared to the corresponding oximes.
Figure 4: Bond dissociation enthalpies (kcal/mol) of oximes and N,N-disubstituted hydroxylamines calculated o...
Scheme 9: Examples demonstrating the low reactivity of the di-tert-butyliminoxyl radical towards the substrat...
Scheme 10: The reactions of di-tert-butyliminoxyl radical with unsaturated hydrocarbons involving hydrogen ato...
Scheme 11: Possible mechanisms of reaction of di-tert-butyliminoxyl radical with alkenes.
Scheme 12: Products of the reaction between di-tert-butyliminoxyl radical and phenol derivatives.
Scheme 13: The reaction of di-tert-butyliminoxyl radical with amines.
Scheme 14: Reaction of di-tert-butyliminoxyl radicals with organolithium reagents.
Scheme 15: Cross-dehydrogenative C–O coupling of 1,3-dicarbonyl compounds with oximes under the action of mang...
Scheme 16: Cross-dehydrogenative C–O coupling of 1,3-dicarbonyl compounds with oximes under the action of Cu(BF...
Scheme 17: Oxidative C–O coupling of benzylmalononitrile (47) with 3-(hydroxyimino)pentane-2,4-dione (19).
Scheme 18: The proposed mechanism of the oxidative coupling of benzylmalononitrile (47) with diacetyl oxime (19...
Scheme 19: Oxidative C–O coupling of pyrazolones with oximes under the action of Fe(ClO4)3.
Scheme 20: The reaction of diacetyliminoxyl radical with pyrazolones.
Scheme 21: Oxidative C–O coupling of oximes with acetonitrile, ketones, and esters.
Scheme 22: Intramolecular cyclizations of oxime radicals to form substituted isoxazolines or cyclic nitrones.
Scheme 23: TEMPO-mediated oxidative cyclization of oximes with C–H bond cleavage.
Scheme 24: Proposed reaction mechanism of oxidative cyclization of oximes with C–H bond cleavage.
Scheme 25: Selectfluor/Bu4NI-mediated C–H oxidative cyclization of oximes.
Scheme 26: Oxidative cyclization of N-benzyl amidoximes to 1,2,4-oxadiazoles.
Scheme 27: The formation of quinazolinone 73a from 5-phenyl-4,5-dihydro-1,2,4-oxadiazole 74 under air.
Scheme 28: DDQ-mediated oxidative cyclization of thiohydroximic acids.
Scheme 29: Plausible mechanism of the oxidative cyclization of thiohydroximic acids.
Scheme 30: Silver-mediated oxidative cyclization of α-halogenated ketoximes and 1,3-dicarbonyl compounds.
Scheme 31: Possible pathway of one-pot oxidative cyclization of α-halogenated ketoximes and 1,3-dicarbonyl com...
Scheme 32: T(p-F)PPT-catalyzed oxidative cyclization of oximes with the formation of 1,2,4-oxadiazolines.
Scheme 33: Intramolecular cyclization of iminoxyl radicals involving multiple C=C and N=N bonds.
Scheme 34: Oxidative cyclization of β,γ- and γ,δ-unsaturated oximes employing the DEAD or TEMPO/DEAD system wi...
Scheme 35: Cobalt-catalyzed aerobic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 36: Manganese-catalyzed aerobic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 37: Visible light photocatalytic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 38: TBAI/TBHP-mediated radical cascade cyclization of the β,γ-unsaturated oximes.
Scheme 39: TBAI/TBHP-mediated radical cascade cyclization of vinyl isocyanides with β,γ-unsaturated oximes.
Scheme 40: tert-Butylnitrite-mediated oxidative cyclization of unsaturated oximes with the introduction of an ...
Scheme 41: Transformation of unsaturated oxime to oxyiminomethylisoxazoline via the confirmed dimeric nitroso ...
Scheme 42: tert-Butylnitrite-mediated oxidative cyclization of unsaturated oximes with the introduction of a n...
Scheme 43: Synthesis of cyano-substituted oxazolines from unsaturated oximes using the TBN/[RuCl2(p-cymene)]2 ...
Scheme 44: Synthesis of trifluoromethylthiolated isoxazolines from unsaturated oximes.
Scheme 45: Copper-сatalyzed oxidative cyclization of β,γ-unsaturated oximes with the introduction of an azido ...
Scheme 46: TBHP-mediated oxidative cascade cyclization of β,γ-unsaturated oximes and unsaturated N-arylamides.
Scheme 47: Copper-сatalyzed oxidative cyclization of unsaturated oximes with the introduction of an amino grou...
Scheme 48: TEMPO-mediated oxidative cyclization of unsaturated oximes followed by elimination.
Scheme 49: Oxidative cyclization of β,γ-unsaturated oximes with the introduction of a trifluoromethyl group.
Scheme 50: Oxidative cyclization of unsaturated oximes with the introduction of a nitrile group.
Scheme 51: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a nitrile ...
Scheme 52: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a sulfonyl...
Scheme 53: Oxidative cyclization of β,γ- and γ,δ-unsaturated oximes to isoxazolines with the introduction of a...
Scheme 54: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a thiocyan...
Scheme 55: PhI(OAc)2-mediated oxidative cyclization of oximes with C–S and C–Se bond formation.
Scheme 56: PhI(OAc)2-mediated oxidative cyclization of unsaturated oximes accompanied by alkoxylation.
Scheme 57: PhI(OAc)2-mediated cyclization of unsaturated oximes to methylisoxazolines.
Scheme 58: Oxidative cyclization-alkynylation of unsaturated oximes.
Scheme 59: TEMPO-mediated oxidative cyclization of C-glycoside ketoximes to C-glycosylmethylisoxazoles.
Scheme 60: Silver-сatalyzed oxidative cyclization of β,γ-unsaturated oximes with formation of fluoroalkyl isox...
Scheme 61: Oxidative cyclization of β,γ-unsaturated oximes with the formation of haloalkyl isoxazolines.
Scheme 62: Cyclization of β,γ-unsaturated oximes into haloalkyl isoxazolines under the action of the halogenat...
Scheme 63: Synthesis of haloalkyl isoxazoles and cyclic nitrones via oxidative cyclization and 1,2-halogen shi...
Scheme 64: Electrochemical oxidative cyclization of diaryl oximes.
Scheme 65: Copper-сatalyzed cyclization and dioxygenation oximes containing a triple C≡C bond.
Scheme 66: Photoredox-catalyzed sulfonylation of β,γ-unsaturated oximes by sulfonyl hydrazides.
Scheme 67: Oxidative cyclization of β,γ-unsaturated oximes with introduction of sulfonate group.
Scheme 68: Ultrasound-promoted oxidative cyclization of β,γ-unsaturated oximes.
Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules
- Valerian Dragutan,
- Ileana Dragutan,
- Albert Demonceau and
- Lionel Delaude
Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68
- Kaliappan et al. [93] described a highly efficient synthesis of C-aryl glycosides, which are naturally occurring compounds of biological relevance. Starting from a glycoside precursor, the intermolecular enyne metathesis with ethylene gas in the presence of the second-generation Grubbs catalyst allowed the
- installation of the1,3-diene units at the anomeric center of the future C-aryl glycoside (23) in high yields (94–98%, Scheme 24). Alternatively, an intramolecular enyne metathesis promoted by the first-generation Grubbs catalyst produced the spiro-C-aryl glycoside 24 from sugar enyne precursors (Scheme 25
- of this concept to obtain the core structure of gilvocarcin, a natural C-aryl glycoside, was also reported. Moreover, the authors attempted a tandem enyne metathesis/Diels–Alder/aromatization to directly prepare the C-aryl glycosides in a one-pot protocol. (−)-Exiguolide The first stereoselective
Graphical Abstract
Scheme 1: Intramolecular (A) and intermolecular (B) enyne metathesis reactions.
Scheme 2: Ene–yne and yne–ene mechanisms for intramolecular enyne metathesis reactions.
Scheme 3: Metallacarbene mechanism in intermolecular enyne metathesis.
Scheme 4: The Oguri strategy for accessing artemisinin analogs 1a–c through enyne metathesis.
Scheme 5: Access to the tetracyclic core of nanolobatolide (2) via tandem enyne metathesis followed by an Eu(...
Scheme 6: Synthesis of (−)-amphidinolide E (3) using an intermolecular enyne metathesis as the key step.
Scheme 7: Synthesis of amphidinolide K (4) by an enyne metathesis route.
Scheme 8: Trost synthesis of des-epoxy-amphidinolide N (5) [72].
Scheme 9: Enyne metathesis between the propargylic derivative and the allylic alcohol in the synthesis of the...
Scheme 10: Synthetic route to amphidinolide N (6a).
Scheme 11: Synthesis of the stereoisomeric precursors of amphidinolide V (7a and 7b) through alkyne ring-closi...
Scheme 12: Synthesis of the anthramycin precursor 8 from ʟ-methionine by a tandem enyne metathesis–cross metat...
Scheme 13: Synthesis of (−)‐clavukerin A (9) and (−)‐isoclavukerin A (10) by an enyne metathesis route startin...
Scheme 14: Synthesis of (−)-isoguaiene (11) through an enyne metathesis as the key step.
Scheme 15: Synthesis of erogorgiaene (12) by a tandem enyne metathesis/cross metathesis sequence using the sec...
Scheme 16: Synthesis of (−)-galanthamine (13) from isovanilin by an enyne metathesis.
Scheme 17: Application of enyne metathesis for the synthesis of kempene diterpenes 14a–c.
Scheme 18: Synthesis of the alkaloid (+)-lycoflexine (15) through enyne metathesis.
Scheme 19: Synthesis of the AB subunits of manzamine A (16a) and E (16b) by enyne metathesis.
Scheme 20: Jung's synthesis of rhodexin A (17) by enyne metathesis/cross metathesis reactions.
Scheme 21: Total synthesis of (−)-flueggine A (18) and (+)-virosaine B (19) from Weinreb amide by enyne metath...
Scheme 22: Access to virgidivarine (20) and virgiboidine (21) by an enyne metathesis route.
Scheme 23: Enyne metathesis approach to (−)-zenkequinone B (22).
Scheme 24: Access to C-aryl glycoside 23 by an intermolecular enyne metathesis/Diels–Alder cycloaddition.
Scheme 25: Synthesis of spiro-C-aryl glycoside 24 by a tandem intramolecular enyne metathesis/Diels–Alder reac...
Scheme 26: Pathways to (−)-exiguolide (25) by Trost’s Ru-catalyzed enyne cross-coupling and cross-metathesis [94].
