Herein, we describe an intermolecular direct branched‐selective α‐alkylation of cyclicketones with simple alkenes as the alkylation agents. Through an enamine‐transition metal cooperative catalysis mode, the α‐alkylation is realized in an atom‐ and step‐economic manner with excellent branched selectivity for preparing β‐branched ketones. Employment of a pair of bulky Brønsted acid and base as additives
Indium-catalyzed coupling reaction between silyl enolates and alkyl chlorides or alkyl ethers
作者:Yoshihiro Nishimoto、Takahiro Saito、Makoto Yasuda、Akio Baba
DOI:10.1016/j.tet.2009.03.106
日期:2009.7
The coupling reactions of alkyl chlorides with silyl enolates catalyzed by InBr3, and the coupling reactions of alkylethers with silyl enolates catalyzed by the combined Lewis acid of InBr3/Me3SiBr are described. In both reaction systems, various types of silyl enolates were used to give corresponding α-alkylated esters, ketones, carboxylic acids, amides, thioesters, and aldehydes.
描述了烷基氯化物与InBr 3催化的烯醇硅酸酯的偶联反应,以及烷基醚与InBr 3 / Me 3 SiBr的路易斯酸催化的烯醇硅酸酯的偶联反应。在两个反应系统中,都使用了各种类型的甲硅烷基烯酸酯,以生成相应的α-烷基化的酯,酮,羧酸,酰胺,硫代酯和醛。
Copper-Catalyzed Asymmetric Conjugate Addition to α-Alkylidene Cycloalkanones
The asymmetriccopper-catalyzedconjugateaddition to α-alkylidene cycloalkanones, substituted at their terminal position with aromatic and aliphatic groups, is reported. While high enantioselectivity is reached using chiral phosphoramidite ligands, with R3Al reagents, moderate diastereoselectivity was observed upon hydrolysis of the aluminium enolates. A Grignard reagent also react with high diastereoselectivity
Coupling Reaction of Alkyl Chlorides with Silyl Enolates Catalyzed by Indium Trihalide
作者:Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1021/ol701684n
日期:2007.11.1
Indium(III) halide catalyzed not only the coupling of alkyl chlorides with silyl enolates derived from esters, ketones, and aldehydes to give a variety of alpha-alkylated carbonylcompounds but also one-pot, three-component reactions of aldehyde enolate, alkyl chloride, and allylsilane or alkynylsilane.
Branched-Selective Intermolecular Ketone α-Alkylation with Unactivated Alkenes via an Enamide Directing Strategy
作者:Dong Xing、Guangbin Dong
DOI:10.1021/jacs.7b08581
日期:2017.10.4
We describe a strategy for intermolecular branched-selective α-alkylation of ketones using simple alkenes as the alkylating agents. Enamides derived from isoindolin-1-one provide an excellent directing template for catalytic activation of ketone α-positions. High branched selectivity is obtained for both aliphatic and aromatic alkenesusing a cationic iridium catalyst. Preliminary mechanistic study