An iridium-catalyzed annulation of chalcones with sulfonylazides via cascade C–H amidation and intramolecular aza-Michael addition was developed, affording a variety of 2-aryl-2,3-dihydro-4-quinolones in moderate to good yields. This reaction features easy operation, readily available starting materials, and the cascade formation of two C–N bonds in one pot.
Selective C-C bonds formation, N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite
作者:Guanxin Zhu、Zheng-Chao Duan、Haiyan Zhu、Dongdong Ye、Dawei Wang
DOI:10.1016/j.cclet.2021.06.060
日期:2022.1
reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds
A new type of C(2)-symmetric chiral bisguanidine was designed as a highly efficient catalyst in the inverse-electron-demandhetero-Diels-Alderreaction of chalcones with azlactones for the first time. A wide variety of gamma,delta-unsaturated delta-lactone derivatives with alpha-quaternary-beta-tertiary stereocenters were obtained in high yields (up to 88%) with excellent enantioselectivities (up to
Highly enantioselective synthesis of γ-substituted butenolides via the vinylogous Mukaiyama–Michael reaction catalyzed by a chiral scandium(iii)–N,N′-dioxide complex
A highly efficient catalytic asymmetric vinylogous Mukaiyama–Michael reaction of the 2-silyloxyfuran with chalcone derivatives, catalyzed by a chiralN,N′-dioxide–scandium(III) complex, has been accomplished which tolerates a wide range of substrates. The reaction proceeds with complete regioselectivities, excellent diastereoselectivities (up to >99 : 1 dr) and good to excellent enantioselectivities
Addition reactions of organic carbanion equivalents via hydrazones in water
作者:Yi-Zhan Wang、Qi Liu、Liang Cheng、Song-Chen Yu、Li Liu、Chao-Jun Li
DOI:10.1016/j.tet.2020.131889
日期:2021.1
The addition of organometallic reagents to unsaturated bonds is one of the most powerful tools for carbon–carbon bondformations. Alkylation throughorganometallic reagents requires stoichiometric quantity of metal and tedious anhydrous operation in most cases. Here, we report “umpolung” nucleophilic additions of hydrazones to Michael acceptors, carbonyls and imines in water. Under the catalysis of