The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide
作者:Olga Lifchits、Manuel Mahlau、Corinna M. Reisinger、Anna Lee、Christophe Farès、Iakov Polyak、Gopinadhanpillai Gopakumar、Walter Thiel、Benjamin List
DOI:10.1021/ja402058v
日期:2013.5.1
Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogenperoxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonylcompounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and
Organozinc reagents in synthesis: the facile generation of 2-(trialkylsilyl)prop-2-enylzinc from 2-bromo-1-trimethylsilylprop-2-ene
作者:James J. Eshelby、Philip J. Parsons、Patrick J. Crowley
DOI:10.1039/p19960000191
日期:——
A range of electrophiles react with 2-(trimethylsilyl)prop-2-enylzinc chloride, which is prepared by sequentially treating 2-bromo-1-trimethylsilylprop-2-ene with ButLi and then zinc chloride. The addition of transition metal catalysts can alter the reactivity of the organometallic compound from prop-2-enylation to prop-1-en-2-ylation.
The construction of 1,3-dienes containing an E-double bond and an exo-methylene group
作者:James J. Eshelby、Philip J. Parsons、Nan C. Sillars、Patrick J. Crowley
DOI:10.1039/c39950001497
日期:——
The use of a tandem Ireland Claisen rearrangement followed by an in situ silicon mediated epoxide fragmentation provides an efficient entry into 1,3-dienes containing an E-double bond and an exo-methylene group; initial results regarding remote chirality control are reported.
利用串联爱尔兰克莱森重排,再通过硅介导的原位环氧化物破碎,可以有效地进入含有一个 E 双键和一个外亚甲基的 1,3-二烯;报告了有关远程手性控制的初步结果。
A short stereoselective synthesis of (−)-serricornin
作者:Isao Shimizu、Kaoruko Hayashi、Masato Oshima
DOI:10.1016/s0040-4039(00)97725-6
日期:1990.1
Palladium-catalyzed reduction of (+)-(E)-(6S, 7S)-4,6-dimethyl-6,7-epoxy-4-nonen-3-one with formic acid gave (−)-(E)-(6S, 7S)-4,6-dimethyl-7-hydroxy-4-nonen-3-one, which was hydrogenated to give (−)-serricornin.
Upon treatment with lithiumorganic nucleophiles, trans-configured oxiranyl carbaldimines are transformed into anti-configured cis-aziridinyl alcohols with excellent diastereoselectivity. This conversion may be explained by a new type of the aza-Payne rearrangement, including first a nucleophilic attack on the imine carbon atom with diastereofacial differentiation followed by an intramolecular nucleophilic opening of the oxiranyl ring with simultaneous formation of the aziridine ring.