Method for Producing Hydroxymethyl Diphenyloxiranes and Corresponding 1-azolylmethyl-1,2-diphenyloxiranes
申请人:Noack Rainer
公开号:US20110295019A1
公开(公告)日:2011-12-01
The present invention relates to a method for producing 1-hydroxymethyl-1,2-diphenyloxiranes from 2,3-diphenylpropenals by means of epoxidation and reduction. The formation of objectionable by-products can be suppressed in that the reduction is started before the 2,3-5 diphenylpropenal is completely converted. The hydroxymethyl diphenyloxiranes represent valuable intermediate products for producing 1-azolylmethyl-1,2-diphenyloxiranes, wherein the latter can be easily produced from said intermediate products by introducing the azolyl group.
Process for producing epoxyalcohols of high optical purity
申请人:ARCO Chemical Technology, L.P.
公开号:EP0454463A2
公开(公告)日:1991-10-30
A process for enriching or improving the optical purity of an asymmetric epoxidation reaction mixture is provided wherein one chiral epoxy alcohol enantiomer, preferably the one present in minor amounts, is effectively separated from the other chiral epoxy alcohol enantiomer by converting the former to an epoxy ester by stereoselective transesterification using a carboxylic acid derivative such as an enol ester and a lipase enzyme and then recovering the desired chiral epoxy alcohol enantiomer or reacting it in situ to form a chiral epoxy alcohol derivative.
Tungsten-Catalyzed Regioselective and Stereospecific Ring Opening of 2,3-Epoxy Alcohols and 2,3-Epoxy Sulfonamides
作者:Chuan Wang、Hisashi Yamamoto
DOI:10.1021/ja5029809
日期:2014.5.14
The first catalytic, highly C3-selective, stereosepecific ring-opening reaction of 2,3-epoxy alcohols and 2,3-epoxy sulfonamides has been accomplished. This process was efficiently promoted by W-salts, and the developed method was applicable to various epoxides with diverse N- and O-nucleophiles affording the products in good to excellent yields (up to 95%) and generally with high regioselectivities (C3:C2 up to >99:1).
Mechanism of asymmetric epoxidation. 1. Kinetics
作者:Scott S. Woodard、M. G. Finn、K. Barry Sharpless
DOI:10.1021/ja00001a018
日期:1991.1
The rate of titanium-tartrate-catalyzed asymmetric epoxidation of allylic alcohols is shown to be first-order in substrate and oxidant, and inverse second order in inhibitor alcohol, under pseudo-first conditions in catalyst. The rate is slowed by substitution of electron-withdrawing substituents on the olefin and varies slightly with solvent, CH2Cl2 being the solvent of choice. Asymmetric induction suffers when the size of the alkyl hydroperoxide is reduced. Kinetic resolution of secondary allylic alcohols is shown to be sensitive to the size of the tartrate ester group and insensitive to the steric nature of inhibitor alcohol. Most importantly, the species containing equimolar amounts of Ti and tartrate is shown to be the most active catalyst in the reaction mixture, mediating reaction at much faster rates that titanium tetraalkoxide alone.