N-tert-Butylbenzenesulfenamide (1)-catalyzed oxidation of various primary and secondary alcohols to the corresponding aldehydes and ketones was efficiently carried out by using N-chlorosuccinimide (NCS) in the coexistence of potassium carbonate and molecular sieves 4 Å at easy-to-control temperatures ranging from 0°C to room temperature. The present catalytic oxidation was performed without giving any
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
Catalytic asymmetric epoxidation and kinetic resolution: modified procedures including in situ derivatization
作者:Yun Gao、Janice M. Klunder、Robert M. Hanson、Hiroko Masamune、Soo Y. Ko、K. Barry Sharpless
DOI:10.1021/ja00253a032
日期:1987.9
The use of 3A or 4A molecularsieves (zeolites) substantially increases the scope of the titanium(IV)-catalyzed asymmetricepoxidation of primary allylicalcohols. Whereas without molecularsievesepoxidations employing only 5 to 10 mol % Ti(O-i-Pr)/sub 4/ generally lead to low conversion or low enantioselectivity, in the presence of molecularsieves such reactions generally lead to high conversion