A convenient synthesis of aziridine-2-carboxylic esters
作者:Johan Legters、Lambertus Thijs、Binne Zwanenburg
DOI:10.1002/recl.19921110101
日期:——
Optically active oxirane-2-carboxylic esters, prepared from allylic alcohols employing the Sharpless epoxidation, were treated with sodium azide. The azido alcohols obtained were subsequently converted into aziridine-2-carboxylicesters by reaction with triphenylphosphine, in good yields and with high optical purity. Various racemic oxirane-2-carboxylic esters were subjected to the same sequence of
β-hydroxy esters in the presence of catalytic amounts of the NiBr2(2,2′-bipyridine) complex has been developped from mixed electrolysis of methallylchloride, or methylchloroacetate with several carbonylcompounds, using a one-compartment cell equiped of a sacrificial zinc anode.
Carboxylate-stabilised sulfur ylides (thetin salts) in asymmetric epoxidation for the synthesis of glycidic acids. Mechanism and implications
作者:Varinder K. Aggarwal、Christina Hebach
DOI:10.1039/b418740g
日期:——
The reaction of carboxylate-stabilised sulfur ylides (thetinsalts) with aldehydes and ketones has been investigated. Using both achiral and chiral sulfur ylides, good yields were obtained with dimsylsodium or LHMDS as bases in DMSO or THF-DMSO mixtures. However, the enantioselectivities observed with a camphor-based sulfide were only moderate (up to 67%). The reaction was studied mechanistically by
Isomerization of glycidic esters and nitriles to the corresponding 2-hydroxy-3-alkenoates and their nitrile derivatives occurred on treatment with triphenylsilyl perchlorate or electrogenerated acid (EG acid). The cyanohydrin moiety of the nitriles 4 was transformed to a formyl group, giving the corresponding enals on treatment with weak base.
Method for producing polydienes and polydiene copolymers with reduced cold flow
申请人:BRIDGESTONE CORPORATION
公开号:US10301397B2
公开(公告)日:2019-05-28
A method for preparing a coupled polymer, the method comprising the steps of (i) polymerizing monomers to form a reactive polymer, and (ii) reacting the reactive polymer with a glycidic ester.