Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

• Natalie Lagesse,
• Luca Pisciottani,
• Maxime Douarre,
• Pascale Godard,
• Brice Kauffmann,
• Vicente Martí-Centelles and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

• conformation in the rotaxane placed the two ferrocene groups with a metal centre-to-metal centre distance of 20.7 Å. Conclusion A five-component, one-pot reaction gave rise to an electroactive [2]rotaxane, through four amidination reactions between two ferrocene-grafted isophthalic acid derivatives and two 1,4

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• the homogeneous photocatalyst. The flow synthesis also prevented the formation of a chlorinated byproduct identified on the batch resins as an intermediate, and purification could be applied to wash out reactants from the first step of the one-pot synthesis, a potentially useful synthetic advantage of

One-pot synthesis of 1,3,5-triazine-2,4-dithione derivatives via three-component reactions

• Gui-Feng Kang and
• Gang Zhang

Beilstein J. Org. Chem. 2020, 16, 1447–1455, doi:10.3762/bjoc.16.120

• 100050, China 10.3762/bjoc.16.120 Abstract A catalyst-free one-pot synthetic methodology was developed for the preparation of 1,3,5-triazine-2,4-dithione derivatives through three-component reactions of arylaldehydes, thiourea, and orthoformates. The procedure tolerated a diverse range of arylaldehydes

• . The products were obtained in moderate to good yields by the one-pot reaction of substituted aldehydes, thiourea, and trialkyl orthoformates. The strategy exhibits the use of inexpensive and easily available reagents and substrates to afford the targeted substituted triazinethione derivatives

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• ]. In addition, we reported that the reaction proceeded smoothly by starting with 1,3-diketones (1) to give 3 in excellent yields in a one-pot reaction. As part of a wider research program aimed at the applications of fluorinated 5-membered heteroaromatic systems, in this paper, we report the

• FL (c) spectra at different solvent compositions of THF/H2O upon excitation at 365 nm (1.0 × 10−5 M); (d–f) F-BKI 9b: photograph (d), UV–vis (e), and FL (f) spectra at different solvent compositions of THF/H2O upon excitation at 380 nm (1.0 × 10−5 M). Selective fluorination of isoxazoles and one-pot

• synthesis of 4-fluoroisoxazoles. One-pot reaction for the synthesis of 3,5-disubstituted 4-fluoroisoxazoles 3. aIsolated yield. bIsolated yield by using conventional heating (oil bath) at 150 °C for 1 h. Synthesis of BKIs 6 either from 1,3-diketones 1 or from isoxazoles 2. Synthesis of enaminoketones 5 and

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

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

•  29). Later, DDQ-mediated oxidative cyclization of amidoximes with the formation of 1,2,4-oxadiazoles (analogous transformation with K3PO4/O2 system was shown above in Scheme 26) was realized without the addition of TsOH [120]. Isoxazolines 82 were synthesized by a one-pot sequence, which included the

Synthesis of pyrrolidinedione-fused hexahydropyrrolo[2,1-a]isoquinolines via three-component [3 + 2] cycloaddition followed by one-pot N-allylation and intramolecular Heck reactions

• Xiaoming Ma,
• Suzhi Meng,
• Xiaofeng Zhang,
• Qiang Zhang,
• Shenghu Yan,
• Yue Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2020, 16, 1225–1233, doi:10.3762/bjoc.16.106

• Two kinds of [3 + 2] cycloaddition intermediates generated from the three-component reactions of 2-bromobenzaldehydes and maleimides with amino esters or amino acids were used for a one-pot N-allylation and intramolecular Heck reactions to form pyrrolidinedione-fused hexahydropyrrolo[2,1-a

• ]isoquinolines. The multicomponent reaction was combined with one-pot reactions to make a synthetic method with good pot, atom and step economy. MeCN was used as a preferable green solvent for the reactions. Keywords: [3 + 2] cycloaddition; Heck reaction; hexahydropyrrolo[2,1-a]isoquinoline; one-pot reactions

• , triazolobenzodiazepines and tetrahydrochromeno[3,4-b]pyrrolizine (Scheme 2) [30][31][32][33][34][35][36][37][38][39]. Many of these scaffolds were synthesized through the combination of MCR and one-pot synthesis. A literature search indicated that a [3 + 2] cycloaddition-initiated method has also been used for the

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• generation of aryl radicals. Although inaccessible to date, a two-step strategy was recently developed by the Procter group. They reported a one-pot organophotocatalytic strategy for the heteroarylation of nonprefunctionalized arenes (Scheme 15) [87]. First, a triaryl sulfonium salt 15.3 is generated from

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• were selected in the build-up of the new electroactive compounds. The commonly used carbazole, phenothiazine, and dimethyldihydroacridine donor units and the scarcely used quinazoline unit as the electron acceptor were chosen for the design of the compounds (Scheme 1). A facile and reliable one-pot

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• in situ generation of a CuCF2H species to access high value-added difluoromethylthiolated molecules starting from organothiocyanates [43]. With this approach, they then developed a one pot, two-step sequence (generation of the organothiocyanates followed by the difluoromethylation step) for the

• standard. A one pot, two-step sequence for the difluoromethylthiolation of various classes of compounds via the in situ generation of CuCF2H from TMSCF2H. A copper-mediated oxidative difluoromethylation of terminal alkynes via the in situ generation of a CuCF2H complex. A copper-mediated oxidative

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• useful Boc-(R)-amino acids 38a,b [44] (Scheme 8). A one-pot double alkylation of the chiral auxiliary 39 with benzyl iodides 40a,b gave cis-dialkyl derivatives 41a,b in 70–72% yield. The subsequent removal of the auxiliary followed by treatment with Fmoc-OSu gave the N-protected 2-fluoro- and 2,6

• affecting the newly introduced fluorine atom was attempted by a two-step, one-pot protocol involving an in situ esterification of a highly electrophilic pyridinium triflate intermediate [77] and afforded the anti-β-fluoro-α-amino acid methyl ester 160a in 52% yield and with 98.8% ee (Scheme 39). On the

Copper-catalysed alkylation of heterocyclic acceptors with organometallic reagents

• Yafei Guo and
• Syuzanna R. Harutyunyan

Beilstein J. Org. Chem. 2020, 16, 1006–1021, doi:10.3762/bjoc.16.90

• enantioselectivity (up to 99% ee) and yield (up to 95%). Remarkably, both alkyl and aromatic Grignard reagents provided a high yield and enantioselectivity in this methodology. Furthermore, the same group reported a one-pot conjugate addition to alkenylheteroarenes with subsequent trapping of the resulting

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• platform for dual catalysis due to their ability to promote both metallocatalysis and photocatalysis in a one-pot system [36][37][38][39]. Martin and co-workers carried out the C–O bond cleavage of alcohols using a cobalt porphyrin under visible light irradiation and a carbon monoxide atmosphere (Scheme 11

• application in the synthesis of quinazolin-4-(3H)-ones by the one-pot reaction between alcohols and 2-aminobenzamide under an oxidative quenching, visible light irradiation using air or oxygen as oxidant (60–81% yields). The authors propose the generation of the superoxide radical anion with the MOF. The

Diversity-oriented synthesis of 17-spirosteroids

• Benjamin Laroche,
• Thomas Bouvarel,
• Martin Louis-Sylvestre and
• Bastien Nay

Beilstein J. Org. Chem. 2020, 16, 880–887, doi:10.3762/bjoc.16.79

• Paris, Palaiseau Cedex, France 10.3762/bjoc.16.79 Abstract A diversity-oriented synthesis (DOS) approach has been used to functionalize 17-ethynyl-17-hydroxysteroids through a one-pot procedure involving a ring-closing enyne metathesis (RCEYM) and a Diels–Alder reaction on the resulting diene, under

• A one-pot RCEYM/Diels–Alder reaction sequence was used to generate a new type of structural diversity in steroids, taking benefit of the propargylic alcohol group of 17-ethynyl-17-hydroxysteroids. After an alkenylation of the alcohol present on the commercially available steroids, providing with

• enyne substrates, the one-pot reaction manifold enabled the anchorage of non-steroidal spirocyclic moieties at C-17. The procedure proved efficient and stereoselective with mestranol and lynestrenol derivatives incorporating a 2-tetrahydrofuranyl spirocycle at C-17. It was more difficult with 2-oxepanyl

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

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

• dienyne precursors in three steps, from (S)- and (R)-citronellal, through a diastereoselective Michael addition, chemoselective dibromoolefination, and a one-pot Wittig olefination/alkyne-bond formation. The enantiopure dienynes were then converted into the enantiomeric hydroazulenes in 53% and 55% yield

• 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

• -metathesis, and a one-pot, two-step stereoselective conjugated allylic alcohol substitution (Scheme 26). It should be emphasized that in this convergent synthesis of (−)-exiguolide, the authors achieved a rigorous stereocontrol of both the exocyclic and endocyclic double bond geometries, as well as the

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• coordination of (t-Bu)3P to CuCl is far greater than that with the diboron species, which results in an enhancement of the catalytic activity (Scheme 65) [128]. The one-pot borylation/protodeboronation of α,β-unsaturated ketones 405 in the presence of CuBr, B2pin2 and H2O as the hydrogen source was developed

Microwave-assisted efficient and facile synthesis of tetramic acid derivatives via a one-pot post-Ugi cascade reaction

• Yong Li,
• Zheng Huang,
• Jia Xu,
• Yong Ding,
• Dian-Yong Tang,
• Jie Lei,
• Hong-yu Li,
• Zhong-Zhu Chen and
• Zhi-Gang Xu

Beilstein J. Org. Chem. 2020, 16, 663–669, doi:10.3762/bjoc.16.63

• developed through an Ugi/Dieckmann cyclization strategy with DBU. This two-step one-pot procedure afforded the targeted tetramic acid analogues in good yields. With commercially available Ugi starting materials, microwave irradiation, a simple operation, excellent yields, and a broad scope, this reaction

• has the potential to produce a large number of tetramic acid analogues, which cannot be easily accessed by the classic synthetic methods. Keywords: Dieckmann cyclization; multicomponent reactions; nitrogen heterocycles; one-pot reaction; Ugi reaction; Introduction Nitrogen-containing heterocycles

• ][28][29] of complex heterocyclic compounds. Recent advance has been focused in the area toward the development of one-pot [30][31][32] Ugi cascade protocol [33][34] as the powerful synthetic strategy for the construction of increasingly complex heterocyclic compounds in the absence of metal catalysts

Cascade trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles

• Ming-Xi Bi,
• Shuai Liu,
• Yangen Huang,
• Xiu-Hua Xu and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2020, 16, 657–662, doi:10.3762/bjoc.16.62

• . Recently, the development of efficient methods for the synthesis of pyrrolo[1,2-a]indol-3-one derivatives has attracted considerable attention. For instance, Song [21] and Liang [22] reported the one-pot synthesis of novel phosphorylated and sulfonylated pyrrolo[1,2-a]indol-3-ones from N-[(3-phenyl

Asymmetric synthesis of CF₂-functionalized aziridines by combined strong Brønsted acid catalysis

• Xing-Fa Tan,
• Fa-Guang Zhang and
• Jun-An Ma

Beilstein J. Org. Chem. 2020, 16, 638–644, doi:10.3762/bjoc.16.60

• hinges upon the discovery of a combined strong Brønsted acid system comprised of a chiral disulfonimide and 2-carboxyphenylboronic acid. Results and Discussion We commenced the desired one-pot transformation by conducting the model reaction between phenylglyoxal monohydrate (1a), 4-methoxyaniline (2a

• with excellent enantiopurity as a single diastereoisomer (>99% ee, >50:1 dr, Scheme 2). By the aid of the developed one-pot aza-Darzens reaction and dissolution–filtration operation, a series of optically-pure CF2-aziridines 4b–h were furnished in moderate overall yields with uniformly excellent ee and

Synthesis of disparlure and monachalure enantiomers from 2,3-butanediacetals

• Adam Drop,
• Hubert Wojtasek and
• Bożena Frąckowiak-Wojtasek

Beilstein J. Org. Chem. 2020, 16, 616–620, doi:10.3762/bjoc.16.57

• , giving compounds 22 and 23. The butanediacetal groups were then removed with p-toluenesulfonic acid and diols 5 and 6 were obtained with 79% and 64% yield, respectively. They were then used in a well-established three-step, one-pot procedure for epoxide ring closure [26][30][40][41]. Pure (+)-disparlure

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

• Takahide Shimada,
• Shigeki Mori,
• Masatoshi Ishida and
• Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

• -monosubstituted dipyrrin 3a, was obtained via a one-pot reaction in 18% yield (in three steps from 2). On the other hand, the β,β'-diethynyl-substituted BODIPY derivatives 5a and 6a, were synthesized by a similar gold-catalyzed reaction of unsubstituted BODIPY 1a in 38% and 2% yields, respectively, in the

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• ) and Cu(II)@IPSi (1b) was investigated in the one-pot three-component condensation of various benzyl bromides, various phenylacetylenes, and sodium azide (Scheme 1). The authors stated that benzyl azide was formed in situ by the nucleophilic addition of the benzyl bromide and sodium azide. Subsequently

• synthesize benzimidazole–triazole derivatives through a one‐pot sequence of activation of the alkyne, [3 + 2] condensation, cyclization, and aromatization under mild reaction conditions (Scheme 2). Moreover, the BS–Cu(II)@SiO2 (11) catalyst could be recovered and recycled for seven cycles without a notable

• 100 °C for one day, cooled, and filtered. The material Pd–Cu@rGO (78), as heterogeneous nanocatalyst, was prepared by anchoring Pd(OAc)2 on Cu@rGO in toluene via pyrolysis. The catalyst was highly active in one-pot condensations of alkyl/aryl-substituted triazole heterocycles with cycloadditions and

Synthesis of triphenylene-fused phosphole oxides via C–H functionalizations

• Md. Shafiqur Rahman and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2020, 16, 524–529, doi:10.3762/bjoc.16.48

• and the carbohelicene moieties (Scheme 1) [16]. The approach focused on the regioselective one-pot synthesis of a 7-hydroxybenzo[b]phosphole derivative from an 3-alkoxyphenylzinc reagent, an alkyne, and dichlorophenylphosphine [17]. The hydroxy group of this key intermediate served as a handle for the

• catalyst (Scheme 2). This one-pot construction of the benzo[b]phosphole core ensured the preferential phosphole ring closure in proximity of the alkoxy group of the arylzinc reagent 1 (regioselectivity of ≈3:1), presumably due to a secondary interaction between the MOM group and the cobalt catalyst during

Regio- and stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction

• Svetlana V. Amosova,
• Andrey A. Filippov,
• Nataliya A. Makhaeva,
• Alexander I. Albanov and
• Vladimir A. Potapov

Beilstein J. Org. Chem. 2020, 16, 515–523, doi:10.3762/bjoc.16.47

• exhibits unusual properties in nucleophilic reactions. This reagent was obtained [30][31][32] in high yield and with high purity by a one-pot synthesis from divinyl sulfide [33][34][35] and selenium dibromide. The structure of compound 1 suggests the possibility of formation of both seleniranium 2 and

• % yields, respectively. The one-pot synthesis of hitherto unknown bis(1,3-thiaselenol-2-ylmethyl) diselenide (8) in 90% yield from thiaselenole 1 was developed (Scheme 10). The reaction proceeded via the formation of thiaselenole selenocyanate 4, which was in situ converted into diselenide 8. This compound

• alkyl propiolates (77Se NMR data are included). One-pot synthesis of diselenide 8 from thiaselenole 1 (77Se NMR data are included). Synthesis of compounds 6a–j from diselenide 8. Results the reaction of thiaselenole 1 with KSeCN based on 1H NMR spectroscopy monitoring (Figure 1).a Supporting