Synthesis of sulfur karrikin bioisosteres as potential neuroprotectives

• Martin Pošta,
• Václav Zima,
• Lenka Poštová Slavětínská,
• Marika Matoušová and
• Petr Beier

Beilstein J. Org. Chem. 2022, 18, 549–554, doi:10.3762/bjoc.18.57

• closure (Scheme 1). A plausible mechanism for the cyclization of compounds 7 is the Darzens reaction to episulfide, followed by Barton–Kellogg-type reaction with triphenylphosphine and elimination of triphenylphosphine sulfide. Compound 8 showed lower germination activity than KAR1 [22], but achieved IC50

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• ligands (Figure 7a). The normally used analogous smaller-sized host was assembled with naphthalene-walled ligands, which had been used widely in mediating various reactions, including dehydration reaction [65], aza-Darzens reaction [66], and reductive amination [67], etc. [28]. The anionic cage host

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• produced the 2-chloroaziridines 28 with relative cis configuration. The absolute proposed configurations were confirmed by X-ray crystallographic analysis (Scheme 10). An interesting asymmetric vinylogous aza-Darzens reaction was employed to access cis-vinylaziridines 30 and 31. The group of Njardarson

• rearrangement, N-silyllithiumenamide 35 was formed. This strongly nucleophilic species could be traped by the chiral imine (RS)-14, producing 2-chloro-2-aroylaziridines via and aza-Darzens reaction [73]. Importantly, the structure of the final aziridine is determined by the silyl group, and the order of the

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

• , and difluoromethyl vinyl sulfonium salts as the fluorinating partner en route to various CF2-substituted aziridines [27][28][29][30][31], and a general protocol to chiral CF2-aziridines remains an unsolved challenge. Thus, herein we report a diastereo- and enantioselective aza-Darzens reaction between

• 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

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• 1.84 as the nucleophile has been successfully conducted (Scheme 15) [49]. The nitrile unit is partially reduced and hydrolysed to the benzaldehyde 1.71 using Raney-Ni under transfer hydrogenation conditions in wet formic acid. A Darzens reaction between this aldehyde and ethyl chloroacetate in the

Facile synthesis of functionalized spiro[indoline-3,2'-oxiran]-2-ones by Darzens reaction

• Qin Fu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 918–924, doi:10.3762/bjoc.9.105

• Qin Fu Chao-Guo Yan College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China 10.3762/bjoc.9.105 Abstract A series of functionalized spiro[indoline-3,2'-oxiran]-2-ones was efficiently synthesized by Darzens reaction of phenacyl bromides with isatins both with N

• -alkyl groups and without N-substituent in the presence of potassium carbonate as a base catalyst. When two equivalents phenacyl bromides were used in the reaction, the N-substitution reaction of isatin also finished with the formation of spiro-oxirane-oxindoles. Keywords: Darzens reaction; isatin

• ratios. It is known that the closure of the epoxy ring would form cis/trans isomers in the Darzens reaction process. Here the N-benzyl and the N-butyl group in the oxindole moiety may decrease the steric effect of formation of the epoxy ring and lead to the easier formation of the relatively unstable cis

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• utilizes the natural negative polarity of the C9 carbon for the construction of an advanced intermediate en route to a mitomycin [147]. A Darzens reaction using the azomethine electrophile 200 provided an easy entry for the construction of the starting cis aziridine 202 which was converted in five steps to