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Search for "serine" in Full Text gives 148 result(s) in Beilstein Journal of Organic Chemistry.
Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds
- Ekaterina V. Berezhnaya,
- Alexander I. Ponyaev,
- Vitali M. Boitsov and
- Alexander V. Stepakov
Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55
- -serine, ʟ-methionine, β-naphthylalanine, phenylglycine, 4-iodophenylalanine, on the achiral Cu(I)/L17 complex leads to the formation of enolates with copper-centered chirality in the form of complex D. Next, complex D interacts with dipolarophiles 53, including fumaronitrile, N-substituted maleimides, β
Graphical Abstract
Scheme 1: Strategies for the preparation of pyrrolidine derivatives by (3 + 2) cycloaddition of azomethine yl...
Scheme 2: (3 + 2) Cycloaddition of iminoesters to dimethylmaleate.
Scheme 3: Cycloaddition of 1 with various dipolarophiles catalyzed by Ag(I)-L1.
Scheme 4: Cycloaddition of 1 with tert-butyl acrylate catalyzed by Ag(I)-L2.
Scheme 5: Cycloaddition of 1 with dimethyl maleate catalyzed by Cu(I)-L3.
Scheme 6: Cycloaddition of 1 with alkenes catalyzed by Zn(II)-t-Bu-BOX (L4).
Scheme 7: (3 + 2) Cycloaddition of iminoesters to acrylates.
Scheme 8: Catalytic double (3 + 2) cycloaddition to form pyrrolizidine derivatives.
Scheme 9: (3 + 2) Cycloaddition of iminoethers to vinyl phenyl sulfone.
Scheme 10: Regiodivergent and enantioselective synthesis of pyrrolidines 16 and 17.
Scheme 11: Substrate-controlled regioreversible "normal" and "incomplete" 1,3-dipolar cycloaddition.
Scheme 12: Enantioselective synthesis of exo-/endo-pyrrolidines.
Scheme 13: (3 + 2) Cycloaddition of iminoethers 21 to dipolarophiles 22–24.
Scheme 14: Synthesis of bicyclic pyrrolidines 29 from cyclopentene-1,3-diones.
Scheme 15: (3 + 2) Cycloaddition of aldimine esters and allyl alcohols using copper-ruthenium catalysis.
Scheme 16: Synthesis of 3,3-difluoro- and 3,3,4-trifluoropyrrolidine derivatives.
Scheme 17: Use of iminoesters from natural compounds and pharmaceuticals for reactions with 1,1-difluoro- and ...
Scheme 18: Reaction of iminoesters with 1,3-enynes.
Scheme 19: Synthesis of pyrrolidines from iminoesters and vinyl(hetero)arenes.
Scheme 20: Synthesis of exo-pyrrolidines 42 and 43.
Scheme 21: Enantioselective synthesis of heteroarylpyrrolidines 45 and 46.
Scheme 22: Catalytic reaction of (3 + 2) cycloaddition of imines 12 to benzofulvenes 47.
Scheme 23: Fullerene as a dipolarophile in (3 + 2) cycloaddition reactions.
Scheme 24: Asymmetric synthesis of optically active tetrasubstituted pyrrolidines 54.
Scheme 25: (3 + 2) Cycloaddition reaction of imines 55 and α,β-unsaturated aldehydes.
Scheme 26: Probable mechanism of enantioselective (3 + 2) cycloaddition of azomethine ylides to α,β-unsaturate...
Scheme 27: Cycloaddition between iminoesters 12 and sulfinylimines 58.
Scheme 28: (3 + 2) Cycloaddition between triarylideneacetylacetone and azomethine ylides in the presence of ti...
Scheme 29: Stereoselective synthesis of decahydropyrrolo[2,1,5-cd]indolizine 66.
Scheme 30: Synthesis of policyclic derivatives 71 and 72.
Scheme 31: Catalytic аsymmetric (3 + 2) сycloaddition of 2-pyridylimines with N-methylmaleimide.
Scheme 32: Catalytic аsymmetric (3 + 2) сycloaddition of 2-pyridylimines 1 with other dipolarophiles.
Scheme 33: Enantioselective (3 + 2) cycloaddition of silylimine with various dipolarophiles.
Scheme 34: Proposed mechanism of formation of pyrrolidines 78.
Scheme 35: Synthesis of polyheterocyclic pyrrolidines 82–91.
Scheme 36: Synthesis of spirocyclic (95) and fused (96) pyrrolidines.
Scheme 37: (3 + 2) Cycloaddition involving aromatic aldehydes 97, N-propargylmaleimide (98) and α-amino acids ...
Scheme 38: Synthesis of pyrrolizidines 106 and by-product 107.
Scheme 39: Iridium-catalyzed three-component cascade (3 + 2) cycloaddition.
Scheme 40: Intramolecular (3 + 2) cycloaddition of N-alkenylpyrrole-2-carbaldehyde 110 and α-amino acids.
Scheme 41: Three-component (3 + 2) cycloaddition involving fullerene.
Scheme 42: Four-component stereoselective one-pot synthesis of spiro-cycloadducts 119–122.
Scheme 43: Reactions of azomethine ylide 123 with cyclopropenes.
Scheme 44: Three-component reactions involving ninhydrin, cyclopropenes and acyclic α-amino acids.
Scheme 45: Reaction of cyclopropenes 138 with the N-protonated form of Ruhemann purple 137.
Scheme 46: Enantioselective (3 + 2) cycloaddition of azomethine ylides generated in situ from isatins and amin...
Scheme 47: (3 + 2) Cycloaddition of cyclohexenone 143, isatins 140 and aminomalonic diesters 141, catalyzed by...
Scheme 48: Enantioselective (3 + 2) cycloaddition of azomethine ylides generated in situ from isatins and amin...
Scheme 49: Enantioselective (3 + 2) cycloaddition of azomethine ylides generated in situ from isatins and benz...
Scheme 50: (3 + 2) Cycloaddition involving isatins, azetidine-2-carboxylic acid, maleimides or itaconimides.
Scheme 51: (3 + 2) Cycloaddition involving isatins, amino acids and tetraethylvinylidenebis(phosphonate).
Scheme 52: Synthesis of spirooxindoles 156 from triarylideneacetylacetones 155.
Scheme 53: Synthesis of spirooxindole derivatives 157–160.
Scheme 54: Synthesis of hybrid spiro-heterocycles 164–166.
Scheme 55: Formation of azomethine ylide from isatin and sarcosine.
Scheme 56: (3 + 2) Cycloaddition involving isatins, amino acids and trans-3-benzoylacrylic acid.
Scheme 57: Regioselective synthesis of spirooxindoles 170.
Scheme 58: Synthesis of hybrid spiro-heterocycles 86.
Scheme 59: (3 + 2) Cycloaddition involving acenaphthenequinones, amino acids and cyclopropenes.
Scheme 60: Synthesis of hybrid glyco-3-nitrochromane cycloadducts 179.
Scheme 61: Synthesis of spiro[indenoquinoxaline-(thia)pyrrolizidines] 90a.
Scheme 62: Three-component reactions of cyclopropenes, 11H-indeno[1,2-b]quinoxalin-11-onesand α-amino acids, s...
Scheme 63: Synthesis of hybrid glyco-3-nitrochromane cycloadducts 92.
Scheme 64: (3 + 2) Cycloaddition of 11H-benzo[4,5]imidazo[1,2-a]indol-11-one (189) with cyclopropenes and male...
Scheme 65: Diastereoselective synthesis of spiro derivatives of barbituric acid from alloxan 193, α-amino acid...
Scheme 66: Probable mechanism of formation of azomethine ylide from alloxan and ʟ-proline.
Scheme 67: Three-component reactions involving tryptanthrin 196, α-amino acids and cyclopropenes.
Advantages of PROTACs in achieving selective degradation of homologous protein families
- Luxi Yang,
- Xinfei Mao,
- Jingyi Zhang,
- Jing Shu,
- Wenhai Huang,
- Xiaowu Dong,
- Yinqiao Chen and
- Mingfei Wu
Beilstein J. Org. Chem. 2026, 22, 628–661, doi:10.3762/bjoc.22.49
- overall selectivity of PROTACs, utilizing several high-profile targets as illustrative examples. CDK Cyclin-dependent kinases (CDKs) are members of the serine/threonine (S/T) kinase subfamily comprising 21 CDK enzymes [44]. CDK1, 2, 3, 4, and 6 play a key role in cell cycle regulation. CDK7, 8, 9, and 11
Graphical Abstract
Figure 1: Mechanism of a PROTAC-mediated targeted protein degradation. Created in BioRender. Wu, M. (2026) ht...
Figure 2: CDK4/6 PROTACs with alkyl or PEG chains as linkers.
Figure 3: CDK4/6 PROTACs with triazole-containing linkers.
Figure 4: Structures of AT-7519 (7) and FN-1501 (8), and CDK9 degrading PROTACs based on compound 8 with vari...
Figure 5: CDK9 PROTACs with alkane chain as linkers or triazole linkers.
Figure 6: Structures of HDAC6 inhibitors ACY1215 (17) and ACY-241 (18), as well as the structure of PROTACs 1...
Figure 7: C4-linked-series and C5-linked-series of HDAC6 PROTACs.
Figure 8: Structures of VHL-based degraders.
Figure 9: Structures of VHL-based and CRBN-based selective HDAC PROTACs.
Figure 10: Structures of the “amide series” and “phenyl series” PROTACs studied by Crews et al.
Figure 11: Structures of the “amide series” PROTACs.
Figure 12: Structures of the “phenyl series” PROTACs.
Figure 13: Structures of JQ1 (34) and MZ1 (35).
Figure 14: Structures of macro-PROTAC-1 and SHD913.
Figure 15: Commonly utilized thalidomide-derived CRBN ligands and possible linker attachment styles. A1, A2: p...
Figure 16: VHL ligands frequently used in PROTACs. Linker attachment options are represented with curly bonds ...
Figure 17: Varying the inhibitor warhead and the recruited E3 ligase permits targets to be accessed for degrad...
Figure 18: Structures of YX-2-233 (42) and YX-2-107 (43).
Figure 19: Structures of compounds 44 and 45.
Figure 20: Design of the SGK3 PROTACs.
Figure 21: CRBN, VHL, and IAP ligands used when designing HDAC-PROTACs.
Figure 22: CDK4/6-PROTACs with different E3 ligands targeting the same E3 ubiquitin ligase.
Figure 23: Structural basis for the selective degradation of CDK6 over CDK4 by PROTAC 2. (A) CDK4–molecule 2–C...
Figure 24: Regarding the PPI-driven selectivity mechanism of two PROTAC molecules, SJF-α and SJF-δ, for p38α a...
Figure 25: Co-crystal structure and ultra-high selectivity of the STAT6 PROTAC degrader AK-1690. (A) STAT6–AK-...
Towards the targeted protein degradation of CK2: design and synthesis of CAM4066-based PROTACs
- Sophie Day-Riley,
- Sona Krajcovicova,
- Aryaman Raj Sokhal,
- Jan L. Venne,
- Paul Brear,
- Marko Hyvönen,
- Benjamin C. Whitehurst,
- Jason S. Carroll and
- David R. Spring
Beilstein J. Org. Chem. 2026, 22, 611–619, doi:10.3762/bjoc.22.47
- Cambridge Institute, Robinson Way, Cambridge, CB2 0RE, United Kingdom 10.3762/bjoc.22.47 Abstract Human protein kinase CK2 is a constitutively active serine/threonine kinase implicated in numerous cancers. Although ATP-competitive inhibitors such as CX-4945 show therapeutic potential, they are limited by
- regulate key cellular processes through the phosphorylation of protein substrates. Dysregulation of kinase activity, often through mutation or altered expression, is associated with numerous malignancies [1]. CK2 (previously called casein kinase 2), a constitutively active serine/threonine kinase
Graphical Abstract
Figure 1: Design strategy and validation. A) Structure of CAM4066 (1) that served as a model design for the d...
Scheme 1: Synthesis of the key ligand-linker PROTAC precursors. For compound 14, HATU/DIPEA has been used ins...
Scheme 2: (A) Synthesis of final VHL PROTACs; (B) Synthesis of final CRBN PROTACs. Abbreviations: Boc = tert-...
Figure 2: Full structures of final VHL PROTACs 23–26 and CRBN PROTACs 28 and 29.
Structural reassignment of compound 968, an allosteric glutaminase inhibitor
- Lindsey A. Albertelli,
- Sainabou Jallow,
- Chun Li and
- Scott M. Ulrich
Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33
- inhibits glutaminase by covalently labeling the catalytic serine [8]. DON inhibits other glutamine-utilizing enzymes such as asparagine synthetase and has activity against a wide range of cancer cell lines [9][10]. BPTES is a potent allosteric inhibitor of GAC/KGA that binds at the dimer–dimer interface
Graphical Abstract
Figure 1: The glutaminase enzymes GLS1 and GLS2 catalyze the hydrolysis of glutamine to glutamate and ammonia...
Figure 2: The cycloaddition reaction between an arylaldehyde (shown here is the specific aldehyde that produc...
Figure 3: A) 1H NMR spectra of compound 968 purchased from Sigma-Aldrich (top), the same compound synthesized...
Figure 4: The cyclocondensation reaction that produces compound 968 and related compounds.
Total synthesis of asperdinones B, C, D, E and terezine D
- Ravi Devarajappa and
- Stephen Hanessian
Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210
- prenylindoles (Figure 1, approach B) which would rely on a Negishi cross-coupling reaction [37][38] using Jackson’s iodozinc N-Boc-ʟ-serine methyl ester [39] and 3-iodoallyl- or 3-iodoprenylindoles (Figure 3). Related Negishi cross-coupling reactions have been reported for bromoindoles [40] and 3-iodo-N-Boc-7
- amino acid reagent that could be removed under non-acidic conditions after the cross-coupling reaction. To this end, we prepared iodo N-Fmoc-ᴅ-alanyl anthranilamide methyl ester 29 from ᴅ-serine. Treatment of prenylindoles 14–17 with iodine and KOH followed by acetylation afforded the corresponding
Graphical Abstract
Figure 1: Structures of prenylindole alkaloids derived from tryptophan.
Figure 2: Representative retrosynthetic considerations for 7-prenyl- and 7-allyltryptophan.
Scheme 1: C-7 Functionalization of 7-iodo-Nα-Boc-tryptophan methyl ester.
Scheme 2: C-7 Prenylation via C–H activation.
Figure 3: Negishi cross-coupling of allyl- and prenyl(iodo)indoles.
Scheme 3: Synthesis of prenyl- and allylindoles.
Scheme 4: Markovnikov hydrochlorination and hydrotrifluoroacetylation.
Scheme 5: Synthesis of asperdinones B–E 1–4.
Scheme 6: Control experiment.
Scheme 7: Control experiment of the Negishi cross-coupling reaction.
Scheme 8: Synthesis of terezine D and ent-asperdinone E.
Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis
- Lihua Wei,
- Rui Yang,
- Zhifeng Shi and
- Zhiqiang Ma
Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151
- . Lipases commonly share typical sequences of α-helices and β-strands and possess a catalytic triad consisting of serine (Ser), histidine (His), and aspartate (Asp) or glutamate (Glu). These three amino residues function as a nucleophile-base–acid catalytic system to facilitate esterification, and the
Graphical Abstract
Scheme 1: General mechanism of a lipase-catalyzed esterification.
Scheme 2: Shishido’s synthesis of (−)-xanthorrhizol (4) and (+)-heliannuol D (8).
Scheme 3: Shishido’s synthesis of a) (−)-heliannuol A (15) and b) heliannuol G (20) and heliannuol H (21).
Scheme 4: Deska’s synthesis of hyperione A (30) and ent-hyperione B (31).
Scheme 5: Huang’s synthesis of (+)-brazilin (37).
Scheme 6: Shishido’s synthesis of (−)-heliannuol D (42) and (+)-heliannuol A (43).
Scheme 7: Chênevert’s synthesis of (S)-α-tocotrienol (49).
Scheme 8: Kita’s synthesis of monoester 53.
Scheme 9: Kita’s synthesis of fredericamycin A (60).
Scheme 10: Takabe’s synthesis of (E)-3,7-dimethyl-2-octene-1,8-diol (64).
Scheme 11: Takabe’s synthesis of (18S)-variabilin (70).
Scheme 12: Kawasaki’s synthesis of (S)-Rosaphen (74) and (R)-Rosaphen (75).
Scheme 13: Tokuyama’s synthesis of a) (−)-petrosin (84) and b) (+)-petrosin (86).
Scheme 14: Fukuyama’s synthesis of leustroducsin B (96).
Scheme 15: Nanda’s synthesis of a) fragment 100, b) fragment 106 and c) (−)-rasfonin (109).
Scheme 16: Davies’ synthesis of (+)-pilocarpine (115) and (+)-isopilocarpine (116).
Scheme 17: Ōmura’s synthesis of salinosporamide A (125).
Scheme 18: Kang’s synthesis of ʟ-cladinose (124) and its derivative.
Scheme 19: Kang’s preparation of fragment 139.
Scheme 20: Kang’s synthesis of azithromycin (149).
Scheme 21: Kang’s synthesis of (−)-dysiherbaine (156).
Scheme 22: Kang’s synthesis of (−)-kaitocephalin (166).
Scheme 23: Kang’s synthesis of laidlomycin (180).
Scheme 24: Snyder’s synthesis of arboridinine (190).
Scheme 25: Ma’s synthesis of (+)-alstrostine G (203).
Scheme 26: Trost’s synthesis of (−)-18-epi-peloruside A (215).
Scheme 27: Lindel’s synthesis of (–)-dihydroraputindole (223).
Scheme 28: Iwata’s synthesis of a) (−)-talaromycin B (232) and b) (+)-talaromycin A (235).
Scheme 29: Cook’s synthesis of a) (−)-vincamajinine (240) and b) (−)-11-methoxy-17-epivincamajine (245).
Scheme 30: Cook’s synthesis of (+)-dehydrovoachalotine (249) and voachalotine (250).
Scheme 31: Cook’s synthesis of a) (−)-12-methoxy-Nb-methylvoachalotine (257) and b) (+)-polyneuridine, macusin...
Scheme 32: Trauner’s synthesis of stephadiamine (273).
Scheme 33: Garg’s synthesis of (–)-ψ-akuammigine (285).
Scheme 34: Ding’s synthesis of (+)-18-benzoyldavisinol (293) and (+)-davisinol (294).
Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads
- Scott Rice,
- Julian Chesti,
- William R. T. Mosedale,
- Megan H. Wright,
- Stephen P. Marsden,
- Terry K. Smith and
- Adam Nelson
Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150
- the synthesis of structurally diverse reactive probes bearing S(VI) electrophiles. Proteome-wide screens have shown that S(VI) electrophiles predominantly target lysine and tyrosine [12], although other residues (e.g. serine) may also be targeted within enzyme active sites [13]. It was envisaged that
Graphical Abstract
Figure 1: Envisaged connective synthesis of reactive probes 3 bearing S(VI) electrophilic warheads (WH). Dive...
Scheme 1: Synthesis of α-diazoamide substrates D1–5 of general structure 2 bearing S(VI) electrophiles. Panel...
Figure 2: Structures and reactions of co-substrates. Panel A: structures of the 16 selected co-substrates C1–...
Figure 3: Structures and structure elucidation of intermolecular reaction products. The relevant reactivity m...
Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs
- Almaz A. Zagidullin,
- Emil R. Bulatov,
- Mikhail N. Khrizanforov,
- Damir R. Davletshin,
- Elvina M. Gilyazova,
- Ivan A. Strelkov and
- Vasily A. Miluykov
Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148
- HSA in aqueous medium shows a characteristic oxidation wave that begins to rise around +0.5 V and significantly increases up to +1.2 V vs Ag/AgCl (Figure 3). This wave is attributed to oxidation processes at peptide bonds or specific side chains (such as cysteine, methionine, tyrosine, serine
- . When these agents alkylate the HSA amino acid residues (particularly reactive sites like lysine, cysteine, serine NH2, SH, OH-side chains, and possibly other nucleophilic groups), the resulting covalent modification can disrupt the electroactive centers responsible for the protein’s oxidation peaks
Graphical Abstract
Figure 1: Structures of some pharmacological important phosphorus-containing molecules with oxirane or azirid...
Scheme 1: Synthesis of glycidyl esters of phosphorus acids 1–3.
Figure 2: Dose–response curves for the cytotoxic effects of glycidyl esters of phosphorus acids 1–3 on human ...
Figure 3: Linear sweep voltammograms of 1 × 10−4 М HSA (black) and HSA mixed with each of the three alkylatin...
Figure 4: Chemical structure of alkylating fragment of 1–3 and the associated chemical pathway of its covalen...
Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages
- Keith G. Andrews
Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30
- ”, or “proton wire” [103][104][105][106] or equivalent to balance the electron redistribution, which may explain the low activity of Cram’s model serine protease in Figure 3A [107]. Polarization was addressed by the creative “molecular clefts” of Rebek [108][109]. Although not a cavity per se, clefts
- active site (binding a substrate in an orientation that directs internally catalyzed reactivity) [347][348]. The examples of cavities with functionality discussed above, from Cram’s “full serine protease model” [87], to MOCs with flexible peripheral groups [349], to frameworks with internal proline
- reactivity. (B) Macrocycles with functional sites that react with bound substrates directly. (A) Cram’s serine protease model system [87][88]. The macrocycle showed strong substrate binding (organization), but the model did not show strong acceleration for a hydrolysis reaction. The “organized” catalytic
Graphical Abstract
Figure 1: Catalytic rate enhancements from a reduction in the Gibbs free energy transition barrier can be fra...
Figure 2: Typical catalysis modes using macrocycle cavities performing (non-specific) hydrophobic substrate b...
Figure 3: (A) Cram’s serine protease model system [87,88]. The macrocycle showed strong substrate binding (organizat...
Figure 4: (A) Self-assembling capsules can perform hydrophobic catalysis [116,117]. (B) Resorcin[4]arene building bloc...
Figure 5: (A) Metal-organic cages and key modes in catalysis. (B) Charged metals or ligands can result in +/−...
Figure 6: (A) Frameworks (MOFs, COFs) can be catalysts. (B) Example of a 2D-COF, assembled by dynamic covalen...
Figure 7: (A) Examples of dynamic covalent chemistry used to synthesize organic cages. (B) Organic cages are ...
Figure 8: (A) Design and development of soluble, functionalized, robust organic cages. (B) Examples of modula...
Figure 9: (A) There are 13 metastable conformers (symmetry-corrected) for cage 1 due to permutations of amide...
Recent advances in electrochemical copper catalysis for modern organic synthesis
- Yemin Kim and
- Won Jun Jang
Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9
- enantioselectivity is the introduction of serine-derived bisoxazoline ligands L8 (sBOX). Upon coordination with a copper catalyst, these ligands present second-sphere ester groups, which facilitate the additional stabilization of noncovalent interactions at the penta-coordinated Cu(III) intermediate 82 in the
Graphical Abstract
Figure 1: General mechanisms of traditional and radical-mediated cross-coupling reactions.
Figure 2: Types of electrocatalysis (using anodic oxidation).
Figure 3: Recent developments and features of electrochemical copper catalysis.
Figure 4: Scheme and proposed mechanism for Cu-catalyzed alkynylation and annulation of benzamide.
Figure 5: Scheme and proposed mechanism for Cu-catalyzed asymmetric C–H alkynylation.
Figure 6: Scheme for Cu/TEMPO-catalyzed C–H alkenylation of THIQs.
Figure 7: Scheme and proposed mechanism for Cu-catalyzed electrophotochemical enantioselective cyanation of b...
Figure 8: Scheme and proposed mechanism for Cu-catalyzed electrophotochemical asymmetric heteroarylcyanation ...
Figure 9: Scheme and proposed mechanism for Cu-catalyzed enantioselective regiodivergent cross-dehydrogenativ...
Figure 10: Scheme and proposed mechanism for Cu/Ni-catalyzed stereodivergent homocoupling of benzoxazolyl acet...
Figure 11: Scheme and proposed mechanism for Cu-catalyzed electrochemical amination.
Figure 12: Scheme and proposed mechanism for Cu-catalyzed electrochemical azidation of N-arylenamines and annu...
Figure 13: Scheme and proposed mechanism for Cu-catalyzed electrochemical halogenation.
Figure 14: Scheme and proposed mechanism for Cu-catalyzed asymmetric cyanophosphinoylation of vinylarenes.
Figure 15: Scheme and proposed mechanism for Cu/Co dual-catalyzed asymmetric hydrocyanation of alkenes.
Figure 16: Scheme and proposed mechanism for Cu-catalyzed electrochemical diazidation of olefins.
Figure 17: Scheme and proposed mechanism for Cu-catalyzed electrochemical azidocyanation of alkenes.
Figure 18: Scheme and proposed mechanism for Cu-catalyzed electrophotochemical asymmetric decarboxylative cyan...
Figure 19: Scheme and proposed mechanism for electrocatalytic Chan–Lam coupling.
Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond
- Thomas Ma and
- John Chu
Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253
- ], requires the presence of a nucleophile at the β-position of the amino acid and occurs exclusively on select amino acids. Specifically, cyclodehydration of a serine or threonine (followed by oxidation or reduction) generates an oxazole, oxazoline, or oxazolidine moiety in the NRP backbone, and the analogous
Graphical Abstract
Figure 1: In BGF for microbial natural product discovery, the culture extract is fractionated using chromatog...
Figure 2: In light of BGF’s decreasing return-on-investment, scientists have developed new natural product di...
Figure 3: a) Incorporation of the first five amino acid BBs in daptomycin (highlighted in blue) is illustrate...
Figure 4: Syn-BNPs were synthesized in accordance to predicted NRP structures; shown herein are hits from var...
Figure 5: a) “Offloading” is the final step of NRP biosynthesis, wherein the mature NRP is released from the ...
Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels
- Connor R. M. MacDonald and
- Emily R. Draper
Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220
- ]. The work by Alakpa et al. highlights how important it is to consider how one assesses the impact of co-assembly on a molecular system [20]. AFM suggested that the addition of the surfactant-like Fmoc-serine (Fmoc-S) to the fibrous Fmoc-diphenylalanine (Fmoc-FF) did not impact the structure of the Fmoc
Graphical Abstract
Figure 1: Hierarchical assembly occurring across length scales. Molecular interactions result in fibres which...
Figure 2: Three-dimensional CLSM image of a multicomponent supramolecular structure. The three-dimensional CL...
Figure 3: AFM images of air-dried aqueous Fmoc-FF, Fmoc-S, and 1:1 Fmoc-FF:Fmoc-S solutions. Figure 3 was reprinted f...
Figure 4: (a) 3D CLSM images of macroscopically a self-sorting gel network, where all fibres were stained gre...
Figure 5: (a) 3D AFM topographic image of dried elastin fibre. (b) Indicative height and diameter profile plo...
Figure 6: The nano-to-micro imaging range of SEM and TEM [30]. Cartoons represent the nanoparticles, pores, nanow...
Figure 7: Cartoon of artifacts caused by blotting and thinning. a) Alignment of threadlike micelles (left) [32] a...
Figure 8: (a) Chemical structures of monomer compounds and a schematic of the resulting chiral helical struct...
Figure 9: Commonly observed entanglements of urea-based supramolecular helices. (a) Double helix, (b) quadrup...
Figure 10: (a) SEM image of a single three-stranded braid showing a defect in which the braid separates into s...
Figure 11: Visualization of individual atoms at 1.25 Å resolution. Three apoferritin residues are shown at hig...
Figure 12: Cartoon of a general small-angle scattering setup.
Figure 13: (a) SAXS data and fits for solution in H2O (open symbols) and D2O (closed symbols). Cryo-TEM data f...
Figure 14: (a) A cartoon illustrating the orientation phases caused by shear alignment of WLMs. (b) Rheologica...
Figure 15: (a) Chemical structure of 2NapFF and (b) a cartoon cross-section of the hollow cylinder structure f...
Figure 16: Length scales of scattering and imaging techniques [16,54,55].
Figure 17: A schematic of a hydrogel network showing the significance of various parameters extracted from SAN...
Figure 18: The morphologies of a co-assembled complex dependent on the solvent composition. Figure 18 is from [89] and was ...
Figure 19: Allowed and forbidden crossings of entangled helices. Figure 19 is from [44] and was adapted by permission from ...
Figure 20: (a) Cryo-TEM density map of self-assembled (ʟ,ʟ)-2NapFF. (b) Computational model fit to cryo-TEM ma...
Figure 21: Map showing an incomplete list of global scientific centres providing access to (a) cryo-EM in red ...
Figure 22: SANS at a range of times. Solid lines are fits to a hollow cylinder model (T = 114 min and T = 202 ...
Figure 23: SAXS data of 5 mg/mL alanine-functionalised perylene bisimide (PBI-A) in 20 v/v % MeOH at pH (a) 2;...
Figure 24: Cryo-TEM sample prepared using plunge freezing in liquid nitrogen slush and sublimed for 30 minutes...
A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis
- Nian Li,
- Ruzal Sitdikov,
- Ajit Prabhakar Kale,
- Joost Steverlynck,
- Bo Li and
- Magnus Rueping
Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214
- and cross-coupling of different kinds of amines for approaching symmetric and unsymmetric imines [76]. This method achieved the bioconjugation of several amino acids with benzylamine, the use of phenylalanine (Phe), serine (Ser), and isoleucine (Ile) as substrates led to 85%, 59%, and 29% yield
Graphical Abstract
Figure 1: Classification of LSF reactions in this review.
Scheme 1: C(sp2)–H trifluoromethylation of heteroarenes.
Scheme 2: C(sp2)–H and C(sp3)–H alkylation of complex molecules.
Scheme 3: Electrochemical oxidation-induced intermolecular aromatic C–H sulfonamidation.
Scheme 4: Bioconjugation of tyrosine with (a) phenothiazine and (b) urazole derivatives.
Scheme 5: Electrochemical iodoamination of indoles using unactivated amines.
Scheme 6: Allylic C(sp3)–H aminations with sulfonamides.
Scheme 7: Electrochemical benzylic oxidation of C–H bonds.
Scheme 8: Site-selective electrooxidation of methylarenes to aromatic acetals.
Scheme 9: Electrochemical activation of C–H by electron-deficient W2C nanocrystals.
Scheme 10: α-Acyloxy sulfide preparation via C–H/OH cross-dehydrogenative coupling.
Scheme 11: Aromatic C–H-bond thiolation.
Scheme 12: C(sp2)–H functionalization for the installation of sulfonamide groups.
Scheme 13: Preparation of (hetero)aryl chlorides and vinyl chloride with 1,2-dichloroethane. aCu(OAc)2 (0.05 e...
Scheme 14: Electrochemical dual-oxidation enables access to α-chlorosulfoxides.
Scheme 15: Regio- and chemoselective formyloxylation–bromination/chlorination/trifluoromethylation of alkenes.
Scheme 16: Aziridine formation by coupling amines and alkenes.
Scheme 17: Formation of iminosulfide ethers via difunctionalization of an isocyanide.
Scheme 18: Synthesis of 1,3-difunctionalized molecules via C–C-bond cleavage of arylcyclopropane.
Scheme 19: Electrooxidative amino- and oxyselenation of alkenes. VBImBr = 1-butyl-3-vinylimidazolium bromide.
Scheme 20: Electrooxidative dehydrogenative [4 + 2] annulation of indole derivatives.
Scheme 21: Electrochemical cyclization combined with alkoxylation of triticonazole.
Scheme 22: Electrochemically tuned oxidative [4 + 2] annulation of olefins with hydroxamic acids.
Scheme 23: Electrosynthesis of indole derivatives via cyclization of 2-ethynylanilines.
Scheme 24: Allylic C–H oxidation of mono-, di-, and sesquiterpenes.
Scheme 25: Oxidation of unactivated C–H bonds.
Scheme 26: Fluorination of C(sp3)–H bonds. rAP = rapid alternating polarity.
Scheme 27: C(sp3)–H α-cyanation of secondary piperidines.
Scheme 28: Selective electrochemical hydrolysis of hydrosilanes to silanols.
Scheme 29: Organocatalytic electrochemical amination of benzylic C–H bonds.
Scheme 30: Iodide ion-initiated anodic oxidation reactions.
Scheme 31: Mn(III/IV) electro-catalyzed C(sp3)–H azidation.
Scheme 32: Tailored cobalt–salen complexes enable electrocatalytic intramolecular allylic C–H functionalizatio...
Scheme 33: Cobalt–salen complexes-induced electrochemical (cyclo)additions.
Scheme 34: Electrochemical 1,2-diarylation of alkenes enabled by direct dual C–H functionalization of electron...
Scheme 35: Cobalt-electrocatalyzed atroposelective C–H annulation.
Scheme 36: Nickel-electrocatalyzed C(sp2)–H alkoxylation with secondary alcohols.
Scheme 37: Nickel-catalyzed electrochemical enantioselective amination.
Scheme 38: Ruthenium-electrocatalyzed C(sp2)–H mono- and diacetoxylation.
Scheme 39: Rhodium(III)-catalyzed aryl-C–H phosphorylation enabled by anodic oxidation-induced reductive elimi...
Scheme 40: Asymmetric Lewis-acid catalysis for the synthesis of non-racemic 1,4-dicarbonyl compounds.
Scheme 41: Electrochemical enantioselective C(sp3)–H alkenylation.
Scheme 42: Palladium-catalyzed electrochemical dehydrogenative cross-coupling.
Scheme 43: Ir-electrocatalyzed vinylic C(sp2)–H activation for the annulation between acrylic acids and alkyne...
Scheme 44: Electrochemical gold-catalyzed C(sp3)–C(sp) coupling of alkynes and arylhydrazines.
Scheme 45: Photoelectrochemical alkylation of C–H heteroarenes using organotrifluoroborates.
Scheme 46: Mn-catalyzed photoelectro C(sp3)–H azidation.
Scheme 47: Photoelectrochemical undirected C–H trifluoromethylations of (Het)arenes.
Scheme 48: Photoelectrochemical dehydrogenative cross-coupling of heteroarenes with aliphatic C–H bonds.
Scheme 49: C–H amination via photoelectrochemical Ritter-type reaction.
Scheme 50: Photoelectrochemical multiple oxygenation of C–H bonds.
Scheme 51: Accelerated C(sp3)–H heteroarylations by the f-EPC system.
Scheme 52: Photoelectrochemical cross-coupling of amines.
Scheme 53: Birch electroreduction of arenes. GSW = galvanized steel wire.
Scheme 54: Electroreductive deuterations.
Scheme 55: Chemoselective electrosynthesis using rapid alternating polarity.
Scheme 56: Electroreductive olefin–ketone coupling.
Scheme 57: Electroreductive approach to radical silylation.
Scheme 58: Electrochemical borylation of alkyl halides. CC = carbon close.
Scheme 59: Radical fluoroalkylation of alkenes.
Scheme 60: Electrochemical defluorinative hydrogenation/carboxylation.
Scheme 61: Electrochemical decarboxylative olefination.
Scheme 62: Electrochemical decarboxylative Nozaki–Hiyama–Kishi coupling.
Scheme 63: Nickel-catalyzed electrochemical reductive relay cross-coupling.
Scheme 64: Electrochemical chemo- and regioselective difunctionalization of 1,3-enynes.
Scheme 65: Electrocatalytic doubly decarboxylative crosscoupling.
Scheme 66: Electrocatalytic decarboxylative crosscoupling with aryl halides.
Scheme 67: Nickel-catalyzed electrochemical reductive coupling of halides.
Scheme 68: Nickel-electrocatalyzed enantioselective carboxylation with CO2.
Scheme 69: Reductive electrophotocatalysis for borylation.
Scheme 70: Electromediated photoredox catalysis for selective C(sp3)–O cleavages of phosphinated alcohols to c...
Scheme 71: Stereoselective electro-2-deoxyglycosylation from glycals. MFE = methyl nonafluorobutyl ether.
Scheme 72: Electrochemical peptide modifications.
Scheme 73: Electrochemical α-deuteration of amides.
Scheme 74: Electrochemical synthesis of gem-diselenides.
Scheme 75: Site-selective electrochemical aromatic C–H amination.
Scheme 76: Electrochemical coupling of heteroarenes with heteroaryl phosphonium salts.
Scheme 77: Redox-neutral strategy for the dehydroxyarylation reaction.
Scheme 78: Nickel-catalyzed electrochemical C(sp3)–C(sp2) cross-coupling of benzyl trifluoroborate and halides....
Scheme 79: Paired electrocatalysis for C(sp3)–C(sp2) coupling.
Scheme 80: Redox-neutral strategy for amination of aryl bromides.
Scheme 81: Redox-neutral cross-coupling of aryl halides with weak N-nucleophiles. aProtocol with (+) RVC | RVC...
Scheme 82: Nickel-catalyzed N-arylation of NH-sulfoximines with aryl halides.
Scheme 83: Esterification of carboxylic acids with aryl halides.
Scheme 84: Electrochemically promoted nickel-catalyzed carbon–sulfur-bond formation. GFE = graphite felt elect...
Scheme 85: Electrochemical deoxygenative thiolation by Ni-catalysis. GFE = graphite felt electrode; NFE = nick...
Scheme 86: Electrochemical coupling of peptides with aryl halides.
Scheme 87: Paired electrolysis for the phosphorylation of aryl halides. GFE = graphite felt electrode, FNE = f...
Scheme 88: Redox-neutral alkoxyhalogenation of alkenes.
Computational toolbox for the analysis of protein–glycan interactions
- Ferran Nieto-Fabregat,
- Maria Pia Lenza,
- Angela Marseglia,
- Cristina Di Carluccio,
- Antonio Molinaro,
- Alba Silipo and
- Roberta Marchetti
Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180
- glycosylation: i) N-glycosylation, where a N-acetylglucosamine (GlcNAc) is linked to the nitrogen atom of an asparagine side chain [28]; ii) O-glycosylation, where a GlcNAc or N-acetylgalactosamine (GalNAc) is linked to the hydroxy group of a serine or threonine residue [29]; iii) C-glycosylation, where a
Graphical Abstract
Figure 1: Carbohydrate conformational variability. a) Illustration of Φ, Ψ and ω dihedral angles for a repres...
Figure 2: Monosaccharides diversity in eukaryotes and bacteria. a) Eukaryotic monosaccharides. b) Examples of...
Figure 3: Different glycan representations. The 3’-sialyllactosamine is depicted according to the a) IUPAC no...
Figure 4: Visualisation programs. Different representation of a protein–ligand complex by using the most used...
Figure 5: A schematic representation of useful computational methods to study protein–glycan interactions. a)...
The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)
- Cristina Martini,
- Muhammad Idham Darussalam Mardjan and
- Andrea Basso
Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162
- work described below, KTGS was applied to multicomponent reactions in limited cases [25]. Van der Veken et al. selected as template the protein urokinase plasminogen activator, a serine protease targeted in oncology and inhibited by imidazopyridines [26]. The main challenges of this project were the
Graphical Abstract
Scheme 1: Mechanism of the GBB reaction.
Scheme 2: Comparison of the performance of Sc(OTf)3 with some RE(OTf)3 in a model GBB reaction. Conditions: a...
Scheme 3: Comparison of the performance of various Brønsted acid catalysts in the synthesis of GBB adduct 6. ...
Scheme 4: Synthesis of Brønsted acidic ionic liquid catalyst 7. Conditions: a) neat, 60 °C, 24 h; b) TfOH, DC...
Scheme 5: Aryliodonium derivatives as organic catalysts in the GBB reaction. In the box the proposed binding ...
Scheme 6: DNA-encoded GBB reaction in micelles made of amphiphilic polymer 13. Conditions: a) 13 (50 equiv), ...
Scheme 7: GBB reaction catalyzed by cyclodextrin derivative 14. Conditions: a) 14 (1 mol %), water, 100 °C, 4...
Scheme 8: Proposed mode of activation of CALB. a) activation of the substrates; b) activation of the imine; c...
Scheme 9: One-pot GBB reaction–Suzuki coupling with a bifunctional hybrid biocatalyst. Conditions: a) Pd(0)-C...
Scheme 10: GBB reaction employing 5-HMF (23) as carbonyl component. Conditions: a) TFA (20 mol %), EtOH, 60 °C...
Scheme 11: GBB reaction with β-C-glucopyranosyl aldehyde 26. Conditions: a) InCl3 (20 mol %), MeOH, 70 °C, 2–3...
Scheme 12: GBB reaction with diacetylated 5-formyldeoxyuridine 29, followed by deacetylation of GBB adduct 30....
Scheme 13: GBB reaction with glycal aldehydes 32. Conditions: a) HFIP, 25 °C, 2–4 h.
Scheme 14: Vilsmeier–Haack formylation of 6-β-acetoxyvouacapane (34) and subsequent GBB reaction. Conditions: ...
Scheme 15: GBB reaction of 4-formlyl-PCP 37. Conditions: a) HOAc or HClO4, MeOH/DCM (2:3), rt, 3 d.
Scheme 16: GBB reaction with HexT-aldehyde 39. Conditions: a) 39 (20 nmol) and amidine (20 μmol), MeOH, rt, 6 ...
Scheme 17: GBB reaction of 2,4-diaminopirimidine 41. Conditions: a) Sc(OTf)3 (20 mol %), MeCN, 120 °C (MW), 1 ...
Scheme 18: Synthesis of N-edited guanine derivatives from 3,6-diamine-1,2,4-triazin-5-one 44. Conditions: a) S...
Scheme 19: Synthesis of 2-aminoimidazoles 49 by a Mannich-3CR followed by a one-pot intramolecular oxidative a...
Scheme 20: On DNA Suzuki–Miyaura reaction followed by GBB reaction. Conditions: a) CsOH, sSPhos-Pd-G2; b) AcOH...
Scheme 21: One-pot cascade synthesis of 5-iminoimidazoles. Conditions: a) Na2SO4, DMF, 220 °C (MW).
Scheme 22: GBB reaction of 5-amino-1H-imidazole-4-carbonile 57. Conditions: a) HClO4 (5 mol %), MeOH, rt, 24 h....
Scheme 23: One-pot cascade synthesis of indole-imidazo[1,2,a]pyridine hybrids. In blue the structural motif in...
Scheme 24: One-pot cascade synthesis of fused polycyclic indoles 67 or 69 from indole-3-carbaldehyde. Conditio...
Scheme 25: One-pot cascade synthesis of linked- and bridged polycyclic indoles from indole-2-carbaldehyde (70)...
Scheme 26: One-pot cascade synthesis of pentacyclic dihydroisoquinolines (X = N or CH). In blue the structural...
Scheme 27: One-pot stepwise synthesis of imidazopyridine-fused benzodiazepines 85. Conditions: a) p-TsOH (20 m...
Scheme 28: One-pot stepwise synthesis of benzoxazepinium-fused imidazothiazoles 89. Conditions: a) Yb(OTf)3 (2...
Scheme 29: One-pot stepwise synthesis of fused imidazo[4,5,b]pyridines 95. Conditions: a) HClO4, MeOH, rt, ove...
Scheme 30: Synthesis of heterocyclic polymers via the GBB reaction. Conditions: a) p-TsOH, EtOH, 70 °C, 24 h.
Scheme 31: One-pot multicomponent reaction towards the synthesis of covalent organic frameworks via the GBB re...
Scheme 32: One-pot multicomponent reaction towards the synthesis of covalent organic frameworks via the GBB re...
Scheme 33: GBB-like multicomponent reaction towards the synthesis of benzothiazolpyrroles (X = S) and benzoxaz...
Scheme 34: GBB-like multicomponent reaction towards the formation of imidazo[1,2,a]pyridines. Conditions: a) I2...
Scheme 35: Post-functionalization of GBB products via Ugi reaction. Conditions a) HClO4, DMF, rt, 24 h; b) MeO...
Scheme 36: Post-functionalization of GBB products via Click reaction. Conditions: a) solvent-free, 150 °C, 24 ...
Scheme 37: Post-functionalization of GBB products via cascade alkyne–allene isomerization–intramolecular nucle...
Scheme 38: Post-functionalization of GBB products via metal-catalyzed intramolecular N-arylation. In red and b...
Scheme 39: Post-functionalization of GBB products via isocyanide insertion (X = N or CH). Conditions: a) HClO4...
Scheme 40: Post-functionalization of GBB products via intramolecular nucleophilic addition to nitriles. Condit...
Scheme 41: Post-functionalization of GBB products via Pictet–Spengler cyclization. Conditions: a) 4 N HCl/diox...
Scheme 42: Post-functionalization of GBB products via O-alkylation. Conditions: a) TFA (20 mol %), EtOH, 120 °...
Scheme 43: Post-functionalization of GBB products via macrocyclization (X = -CH2CH2O-, -CH2-, -(CH2)4-). Condi...
Figure 1: Antibacterial activity of GBB-Ugi adducts 113 on both Gram-negative and Gram-positive strains.
Scheme 44: GBB multicomponent reaction using trimethoprim as the precursor. Conditions: a) Yb(OTf)3 or Y(OTf)3...
Figure 2: Antibacterial activity of GBB adducts 152 against MRSA and VRE; NA = not available.
Figure 3: Antibacterial activity of GBB adduct 153 against Leishmania amazonensis promastigotes and amastigot...
Figure 4: Antiviral and anticancer evaluation of the GBB adducts 154a and 154b. In vitro antiproliferative ac...
Figure 5: Anticancer activity of the GBB-furoxan hybrids 145b, 145c and 145d determined through antiprolifera...
Scheme 45: Synthesis and anticancer activity of the GBB-gossypol conjugates. Conditions: a) Sc(OTf)3 (10 mol %...
Figure 6: Anticancer activity of polyheterocycles 133a and 136a against human neuroblastoma. Clonogenic assay...
Figure 7: Development of GBB-adducts 158a and 158b as PD-L1 antagonists. HTRF assays were carried out against...
Figure 8: Development of imidazo[1,2-a]pyridines and imidazo[1,2-a]pyrazines as TDP1 inhibitors. The SMM meth...
Figure 9: GBB adducts 164a–c as anticancer through in vitro HDACs inhibition assays. Additional cytotoxic ass...
Figure 10: GBB adducts 165, 166a and 166b as anti-inflammatory agents through HDAC6 inhibition; NA = not avail...
Scheme 46: GBB reaction of triphenylamine 167. Conditions: a) NH4Cl (10 mol %), MeOH, 80 °C (MW), 1 h.
Scheme 47: 1) Modified GBB-3CR. Conditions: a) TMSCN (1.0 equiv), Sc(OTf)3 (0.2 equiv), MeOH, 140 °C (MW), 20 ...
Scheme 48: GBB reaction to assemble imidazo-fused heterocycle dimers 172. Conditions: a) Sc(OTf)3 (20 mol %), ...
Figure 11: Model compounds 173 and 174, used to study the acid/base-triggered reversible fluorescence response...
Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity
- Moisés Alejandro Alejo Hernandez,
- Katia Pamela Villavicencio Sánchez,
- Rosendo Sánchez Morales,
- Karla Georgina Hernández-Magro Gil,
- David Silverio Moreno-Gutiérrez,
- Eddie Guillermo Sanchez-Rueda,
- Yanet Teresa-Cruz,
- Brian Choi,
- Armando Hernández Garcia,
- Alba Romero-Rodríguez,
- Oscar Juárez,
- Siseth Martínez-Caballero,
- Mario Figueroa and
- Corina-Diana Ceapă
Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159
- resulting peptides exhibit unique structural features due to thioether bridges between dehydrated serine or threonine (Dha/Dhb) and cysteine (Cys). These thioether bridges lead to cyclic peptides with the modified amino acid lanthionine (Dha-Cys) or methyllanthionine (Dhb-Cys). The strong antimicrobial
- physicochemical characteristics, number of predicted cycles (one cycle or more was required), the presence of serine (Ser) and threonine (Thr) residues, and the characteristic cleavage site of the C39 peptidases domain (GG or GA) (Table S2 in Supporting Information File 1) obtained in RiPPMiner [5]. The nine
Graphical Abstract
Figure 1: Phylogenetic trees of the LanM synthetase amino acid sequences. Unrooted phylogenetic tree of all t...
Figure 2: The phylogenetic tree was built by concatenating 1000 shared clostridial genes (left) between the s...
Figure 3: A. Similarity network created with the ESI web tool with the precursor peptide amino acid sequences...
Figure 4: Mass-spectrometric analysis of purified clostrisin and cellulosin (ESIMS spectra). A1 and A2: CloA2...
Figure 5: Growth curves of the strains with the bacterial activity of the samples. A. Precursor peptide for C...
Figure 6: Atomic force microscopy images (peak force mode) of S. epidermidis MIQ43 incubated with the differe...
Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry
- Maria-Paula Schröder,
- Isabel P.-M. Pfeiffer and
- Silja Mordhorst
Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147
- -serine, which provides the methyl group in this case. Another methyl donor that provides a C1 building block for ʟ-methionine and subsequent SAM synthesis is betaine. Betaine-homocysteine MT remethylates ʟ-homocysteine to ʟ-methionine. Non-SAM-dependent MTs catalyse B12-dependent methylations using the
- with N-terminal alanine, serine, threonine, glycine, and methionine residues, as well as the antibiotics nisin and haloduracin with good efficiency. Nisin was methylated on its N-terminal isoleucine and on the side chain of Lys12, where two methylations occurred. It is important to note that N
Graphical Abstract
Figure 1: Schematic representation of the different acceptor regions for the methylation of RiPPs discussed i...
Figure 2: Schematic overview of different methylation strategies for amino acids and peptides. There are seve...
Figure 3: Biological methylation. A) Methyl donors from biological systems. The transferred methyl group is h...
Figure 4: Chemical structures of RiPPs with diverse O-, N-, C-, and S-methylations. Amino acids of lassomycin...
Figure 5: The three-dimensional structures of the conventional O-MTs OlvSA (model structure calculated by Col...
Figure 6: Reaction scheme of the PAMT´s catalysis, leading to the enzymatic conversion of aspartate to aspart...
Figure 7: Structural organisation of the OphMA homodimer. A) Schematic representation. The MT domain is colou...
Figure 8: Overview of the protein architectures and core peptide compositions of borosin N-MTs as defined by ...
Figure 9: Radical SAM C-methyltransferases. A) The different rSAM MT classes containing different functional ...
Figure 10: The three-dimensional structures of the rSAM C-MTs TsrM with bound cobalamin and [4Fe-4S] cluster (...
Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty
- Weimao Zhong and
- Vinayak Agarwal
Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146
- substituted saccharides. The vast diversity among CEs is organized into 16 different families [123]. Members of the CE6 family are typical serine-type esterases. A cold-adapted CE6 enzyme, CEST, was cloned and expressed in E. coli from Microbulbifer thermotolerans DAU221 with a temperature optimum of 15 °C
Graphical Abstract
Figure 1: Oceanic distribution and marine holobiont sources of Microbulbifer strains described in the literat...
Figure 2: The chemical structure of agarose with the key β-1,4 linkage denoted.
Figure 3: The chemical structure of the biopolymer alginate.
Figure 4: The chemical structure of chitin.
Figure 5: Chemical structures of sulfated polysaccharides κ-, ι-, and λ-carrageenans.
Figure 6: Chemical structures of 4HBA (1) and parabens (2–14) isolated from Microbulbifer strains, and synthe...
Figure 7: Chemical structures of nucleosides 18–20 isolated from Microbulbifer strains.
Figure 8: Chemical structures of alkaloids 21–24 isolated from Microbulbifer strains.
Figure 9: Chemical structures of (2Z,4E)-3-methyl-2,4-decadienoic acid (25) and 4-BP (26) natural products is...
Figure 10: Chemical structures of bulbiferamides 27–30 and pseudobulbiferamides 31–35.
Figure 11: Proposed NRPS assembly lines for the biosynthesis of (A) bulbiferamide A (27) and (B) pseudobulbife...
Figure 12: Chemical structures of 2-heptyl-1H-quinolin-4-one (36, HHQ), 2-heptyl-1-hydroxyquinolin-4-one (37, ...
Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors
- Simone Gräßle,
- Laura Holzhauer,
- Nicolai Wippert,
- Olaf Fuhr,
- Martin Nieger,
- Nicole Jung and
- Stefan Bräse
Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121
- strategies to explore access to triazole–pyrazole hybrids. Triazole–pyrazole hybrids, particularly non-fused heterocycles of this class, have not been investigated systematically. Selected known derivatives (Figure 1, 1–4) inhibit the serine-threonine kinase ERK3 [12] or the cholera-causing bacterium Vibrio
Graphical Abstract
Figure 1: Biologically active pyrazole–triazole hybrids 1–4: inhibitory effect on cholera bacteria [13], antimicr...
Scheme 1: Literature-reported synthetic routes to pyrazole–triazole hybrids: synthesis of azides 7 or 8 from ...
Scheme 2: Synthesis of pyrazolyl azides 19a–v via cleavage of the protecting triazene moiety. For compounds 1...
Scheme 3: Synthesis of pyrazole–triazole hybrids via CuAAC and ORTEP diagrams of triazole products 21sd and 2...
Figure 2: Synthesized triazole–pyrazole hybrids 21aa–vg.
Scheme 4: One-pot synthesis of triazole–pyrazole hybrid 21gd. aOne-pot setup yielded 21gd with unknown impuri...
Scheme 5: Solid-phase synthesis of azidopyrazole 19g and triazole–pyrazole hybrid 21gd by immobilization of a...
New variochelins from soil-isolated Variovorax sp. H002
- Jabal Rahmat Haedar,
- Aya Yoshimura and
- Toshiyuki Wakimoto
Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63
- serine (Ser), a β-hydroxyaspartic acid (Hya), and a unique γ-amino acid biosynthetically originating from an arginine and a methyl malonate (4-amino-7-guanidino-3-hydroxy-2-methylheptanoic acid), with the amino group acylated by a saturated fatty acid. Subsequent HMBC and MS/MS analyses indicated that
- , Ser: serine, Pro: proline, Orn: ornithine). (b) Validation of var biosynthetic gene cluster. The plasmid constructed for the generation of the varG null-mutant strain (varG::cmR) using the cmR gene cassette (left), and HPLC-profile comparison of the Variovorax sp. H002 wild type strain and the varG
Graphical Abstract
Figure 1: (a) Chemical structures and (b) ESIMS/MS of variochelins A–E (1–5) isolated from Variovorax sp. H00...
Figure 2: EIMS of DMOX derivatized free fatty acids derived from variochelins C–E (3–5). (a) 3, (b) 4, and (c...
Figure 3: (a) Plausible biosynthetic pathway of variochelin A–E (1–5). The circles represent domains: A: aden...
Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds
- Xiaofeng Zhang,
- Xiaoming Ma and
- Wei Zhang
Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123
- , serine, and norvaline to give products 11a–f in 53–88% yields with greater than 8.5 dr (Scheme 7). The reactions with leucine and phenylglycine (R2 = iPr and Ph) as amino acids gave mainly mono-cycloaddition products and very little double cycloaddition products 11g and 11h due to the steric hindrance of
Graphical Abstract
Figure 1: Classification of AMYs.
Scheme 1: Aminoester- and amino acid-based AMYs for single and double [3+2] cycloadditions.
Scheme 2: Formation of semi-stabilized AMYs B1 from pyrrolidines.
Scheme 3: Cyclic amine-based AMYs A3 and B1 for [3 + 2] cycloadditions.
Scheme 4: Proposed double cycloaddition reactions involving semi-stabilized AMYs.
Scheme 5: [3 + 2] Cycloaddition for the synthesis of trifluoromethylated pyrrolidines 9.
Figure 2: Biologically interesting pyrrolizidines.
Scheme 6: Double cycloadditions with glycine for the synthesis of products 10 (dr > 9:1).
Scheme 7: Double cycloadditions with α-substituted amino acids leading to products 11 (≈8.5:1 dr).
Scheme 8: Stereochemistry for the formation of products 10 or 11.
Scheme 9: One-pot and stepwise double cycloadditions. Conditions: i) MeCN (0.02 M), 90 °C, 6 h; ii) then AcOH...
Figure 3: Biologically interesting spirooxindole-pyrrolizidines.
Scheme 10: Double cycloadditions for the synthesis of bis[spirooxindole-pyrrolizidine]s.
Scheme 11: Mechanism for the diastereoselective synthesis of bis[spirooxindole-pyrrolizidine]s.
Scheme 12: Stepwise synthesis of triazolobenzodiazepine 21a.
Scheme 13: One-pot synthesis of triazolobenzodiazepines.
Figure 4: Bioactive triazolobenzodiazepine derivatives.
Scheme 14: One-pot synthesis of tetrahydropyrroloquinazolines.
Scheme 15: One-pot synthesis of tetrahydropyrrolobenzodiazepines.
Figure 5: Bioactive pyrroloquinazolines and pyrrolobenzodiazepines.
Scheme 16: Stepwise synthesis of pyrrolo[2,1-a]isoquinolines.
Figure 6: Bioactive pyrrolo[2,1-a]isoquinolines and hexahydropyrrolo[2,1-a]isoquinolines.
Figure 7: Bioactive tetrahydropyrrolothiazoles.
Scheme 17: Pseudo-four-component reaction for the synthesis of tetrahydropyrrolothiazoles 29 and 30 (>4:1 dr).
Scheme 18: One-pot two-step synthesis of spirooxindole-pyrrolothiazoles 31 (>4:1 dr).
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
- -enyl) lipid chain (Figure 9) [88]. The synthesis starts from serine 9.1 and produce (R)-solketal (9.2) following a three-step protocol [89] that was recently revisited [90] (diazotation, esterification, acetalization). Then, the incorporation of the oleyl chain (C18H35) was achieved by the
- amine with acetic anhydride. It is worth noticing that acetamido-PAF 17.13 was previously reported following a different synthesis scheme starting from serine as chiral precursor [96][105]. Recently, is was reported that the acetamido-PAF 17.13 is an activator of the TRPV2 channel leading to
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...
Photoredox catalysis harvesting multiple photon or electrochemical energies
- Mattia Lepori,
- Simon Schmid and
- Joshua P. Barham
Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81
Graphical Abstract
Figure 1: Oxidative and reductive activations of organic compounds harvesting photoredox catalysis.
Figure 2: General catalytic cycles of radical ion conPET (left) and radical ion e-PRC (right).
Figure 3: “Beginner’s guide”: comparison between advantages, capacities, and prospectives of conPET and PEC.
Figure 4: A) conPET reductive dehalogenation of aryl halides with PDI. B) Reductive C–H arylation with pyrrol...
Figure 5: A) Chromoselective mono- and disubstitution or polybrominated pyrimidines with pyrroles. B) Sequent...
Figure 6: A) Synthesis of pyrrolo[1,2-a]quinolines. B) Synthesis of ullazines.
Figure 7: A) Reductive phosphorylation of aryl halides via conPET. B) Selected examples from the substrate sc...
Figure 8: A) Reductive dehalogenation of aryl halides via conPET and selected examples from the substrate sco...
Figure 9: A) Reductive C–H arylation of aryl halides via conPET (top) and selected examples from the substrat...
Figure 10: A) Reductive hydrodehalogenation of aryl halides with Mes-Acr-BF4. B) Selected examples from the su...
Figure 11: A) Reductive hydrodechlorination of aryl chlorides with 4-DPAIPN. B) Proposed formation of CO2•−. C...
Figure 12: A) Reductive conPET borylation with 3CzEPAIPN (top) and selected examples from the substrate scope ...
Figure 13: Scale-up of conPET phosphorylation with 3CzEPAIPN.
Figure 14: A) Borylation of 1d. B) Characteristics and structure of PC1 with green and red parts showing the l...
Figure 15: A) Reductive C–H arylation scope with polysulfide conPET (top) and selected examples from the subst...
Figure 16: Scale-up of A) C–H arylation and B) dehaloborylation with polysulfide photocatalysis in continuous-...
Figure 17: A) Formation of [Ir1]0 and [Ir2]0 upon PET between [Ir1]+ and Et3N. B) Mechanism of multi-photon ta...
Figure 18: A) Reductive hydrodehalogenation of aryl halides via multi-photon tandem photocatalysis. B) Selecte...
Figure 19: A) Carbonylative amidation of aryl halides in continuous flow. B) Selected examples from the substr...
Figure 20: A) General scheme for reductive (RQ) and oxidative quenching (OQ) protocols using [FeIII(btz)3](PF6)...
Figure 21: A) Carbonylative amidation of alkyl iodides with [IrIII(ppy)2(dtbbpy)]PF6. B) Selected examples fro...
Figure 22: A) Carboxylative C–N bond cleavage in cyclic amines. B) Selected examples from the substrate scope....
Figure 23: A) Formal reduction of alkenes to alkanes via transfer hydrogenation. B) Selected examples from the...
Figure 24: A) Birch-type reduction of benzenes with PMP-BPI. B) Selected examples from the substrate scope (sc...
Figure 25: Proposed mechanism of the OH− mediated conPET Birch-type reduction of benzene via generation of sol...
Figure 26: Reductive detosylation of N-tosylated amides with Mes-Acr-BF4. B) Selected examples from the substr...
Figure 27: A) Reductive detosylation of N-tosyl amides by dual PRC. B) Selected examples from the substrate sc...
Figure 28: A) Mechanism of the dual PRC based on PET between [Cu(dap)2]+ and DCA. B) Mechanism of the dual PRC...
Figure 29: A) N–O bond cleavage in Weinreb amides with anthracene. B) N–O bond cleavage in Weinreb amides rely...
Figure 30: A) Pentafluorosulfanylation and fluoride elimination. B) Mechanism of the pentafluorosulfanylation ...
Figure 31: A) α-Alkoxypentafluorosulfanylation (top) and selected examples from the substrate scope (bottom). ...
Figure 32: A) Oxidative amination of arenes with azoles catalyzed by N-Ph PTZ. B) Selected examples from the s...
Figure 33: A) C(sp3)–H bond activation by HAT via chloride oxidation by *N-Ph PTZ•+. B) Proposed mechanism for...
Figure 34: A) Recycling e-PRC C–H azolation of electron-rich arenes with pyrazoles using Mes-Acr+ as a photoca...
Figure 35: A) Radical ion e-PRC direct oxidation of unactivated arenes using TAC+ as an electro-activated phot...
Figure 36: A) Radical ion e-PRC direct oxidation of unactivated arenes using TPA as an electro-activated photo...
Figure 37: Proposed mechanism (top) and mode of preassembly (bottom).
Figure 38: A) Possible preassemblies of reactive (left) vs unreactive (right) arenes. B) Calculated spin densi...
Figure 39: A) Recycling e-PRC C(sp2 )–H acetoxylation of arenes using DDQ as a photocatalyst. B) Proposed cata...
Figure 40: Gram scale hydroxylation of benzene in a recirculated flow setup.
Figure 41: A) Radical ion e-PRC vicinal diamination of alkylarenes using TAC+ as an electro-activated photocat...
Figure 42: A) Sequential oxygenation of multiple adjacent C–H bonds under radical ion e-PRC using TAC+ as an e...
Figure 43: A) Enantioselective recycling e-PRC cyanation of benzylic C–H bonds using ADQS as photocatalyst. B)...
Figure 44: Proposed tandem mechanism by Xu and co-workers.
Figure 45: A) Enantioselective recycling e-PRC decarboxylative cyanation using Cu(acac)2, Ce(OTf)3 and a box l...
Figure 46: A) Enantioselective recycling e-PRC benzylic cyanation using Cu(MeCN)4BF4, box ligand and anthraqui...
Figure 47: A) Radical ion e-PRC acetoxyhydroxylation of aryl olefins using TAC+ as an electro-activated photoc...
Figure 48: Selected examples from the substrate scope.
Figure 49: Photoelectrochemical acetoxyhydroxylation in a recirculated flow setup.
Figure 50: A) Radical ion e-PRC aminooxygenation of aryl olefins using TAC+ as an electro-activated photocatal...
Figure 51: A) Recycling e-PRC C–H alkylation of heteroarenes with organic trifluoroborates using Mes-Acr+ as p...
Figure 52: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using CeCl3·7H2O as catalyst. B) ...
Figure 53: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using Fe(NH4)2(SO4)2·6H2O as cata...
Figure 54: A) Recycling e-PRC C–H alkylation of heteroarenes with alkyl oxalates and 4CzIPN as photocatalyst. ...
Figure 55: A) Recycling e-PRC decarboxylative C–H carbamoylation of heteroarenes using 4CzIPN as photocatalyst...
Figure 56: A) Photoelectrochemical HAT-mediated hydrocarbon activation via the chlorine radical. B) Proposed m...
Figure 57: A) Selected examples from the substrate scope. B) Gram and decagram scale semi-continuous flow PEC ...
Figure 58: A) Photoelectrochemical HAT-mediated dehydrogenative coupling of benzothiazoles with aliphatic C–H ...
Figure 59: A) Photoelectrochemical HAT activation of ethers using electro-activated TAC+ as photocatalyst. B) ...
Figure 60: Selected examples from the substrate scope.
Figure 61: A) Photoelectrochemical HAT-mediated synthesis of alkylated benzimidazo-fused isoquinolinones using...
Figure 62: A) Decoupled photoelectrochemical cerium-catalyzed oxydichlorination of alkynes using CeCl3 as cata...
Figure 63: Proposed decoupled photoelectrochemical mechanism.
Figure 64: A) Decoupled photoelectrochemical ring-opening bromination of tertiary cycloalkanols using MgBr2 as...
Figure 65: A) Recycling e-PRC ring-opening functionalization of cycloalkanols using CeCl3 as catalyst. B) Prop...
Figure 66: Selected examples from the substrate scope of the PEC ring-opening functionalization.
Figure 67: A) Radical ion e-PRC reduction of chloro- and bromoarenes using DCA as catalyst and various accepto...
Figure 68: A) Screening of different phthalimide derivatives as catalyst for the e-PRC reduction of aryl halid...
Figure 69: Screening of different organic catalysts for the e-PRC reduction of trialkylanilium salts.
Figure 70: A) e-PRC reduction of phosphonated phenols and anilinium salts. B) Selected examples from the subst...
Figure 71: A) ConPET and e-PRC reduction of 4-bromobenzonitrile using a naphthalene diimide (NDI) precatalyst ...
Figure 72: A) Radical ion e-PRC reduction of phosphinated aliphatic alcohols with n-BuO-NpMI as catalyst. B) C...
Figure 73: Selected examples from the substrate scope.
Figure 74: A) Recycling e-PRC reductive dimerization of benzylic chlorides using a [Cu2] catalyst. B) Proposed...
Figure 75: A) Decoupled photoelectrochemical C–H alkylation of heteroarenes through deamination of Katritzky s...
Figure 76: Proposed mechanism by Chen and co-workers.
A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes
- Alena V. Dmitrieva,
- Oleg A. Levitskiy,
- Yuri K. Grishin and
- Tatiana V. Magdesieva
Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41
- )-1-benzylpyrrolidine-2-carboxamide) and its Ni(II)–Schiff base complexes formed of glycine, serine, and dehydroalanine are reported. A bulky tert-butyl substituent in the phenylene fragment precludes unwanted oxidative dimerization of the Schiff base complex, making it suitable for targeted
- structurally advantageous (S)-N-benzylproline-derived ligand containing the bulky tert-butyl substituent in the phenylene fragment (L7) is reported. Three Ni(II)–Schiff base derivatives of the new ligand (containing glycine, serine, and dehydroalanine) were obtained. Complexes of this type are most often used
- . Results and Discussion Synthesis The synthetic approach to the chiral ligand L7 as well as to its Ni–Schiff base derivatives containing glycine, serine, dehydroalanine, and cysteine is given in Scheme 2. Commercially available (S)-proline was used as the starting material. To obtain the starting t-Bu
Graphical Abstract
Scheme 1: Selected examples of the chiral ligands used for synthesis of the Ni(II)–Schiff base complexes.
Scheme 2: Synthesis of the chiral ligand L7 and its Ni(II) complexes with glycine, serine, dehydroalanine, an...
Figure 1: Fragment of the NOESY spectrum of the ʟ-(oBrCysNi)L7 complex indicating the correlation between the...
Figure 2: Low-gradient isosurfaces with low densities (blue color of the isosurface corresponds to the hydrog...
Figure 3: Saturated solutions of (GlyNi)L1 (left) and (GlyNi)L7 (right) in diethyl ether.
Figure 4: The CV curves observed for (GlyNi)L7 and (ΔAlaNi)L7 in the anodic and cathodic regions (Pt, CH3CN, ...
Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C
- Karolina Wątroba,
- Małgorzata Pawełczak and
- Marcin Kaźmierczak
Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33
- in chemotherapies to support traditional anticancer drugs. Moreover, there is a growing interest in the topic of cathepsin C inhibition, which directly affects serine protease activity [5][6]. Inhibitors of cathepsin C can be cystatins that show activity against a large group of cysteine proteases [7
Graphical Abstract
Scheme 1: Synthetic strategy towards 5 and 7.
Scheme 2: Synthesis of 9 and 11. (a) R = -CH3; (b) R = -CH(CH3)2; (c) R = -CH2CH(CH3)2; (d) R = -CH(CH3)CH2CH3...
Figure 1: Dixon plot for the hydrolysis of Gly-Phe-pNA substrate catalyzed by bovine cathepsin C in the prese...
