Chiral Epoxides via Borane Reduction of 2-Haloketones Catalyzed by Spiroborate Ester: Application to the Synthesis of Optically Pure 1,2-Hydroxy Ethers and 1,2-Azido Alcohols
作者:Kun Huang、Haiyang Wang、Viatcheslav Stepanenko、Melvin De Jesús、Carilyn Torruellas、Wildeliz Correa、Margarita Ortiz-Marciales
DOI:10.1021/jo102294j
日期:2011.3.18
with 10% spiroaminoborate ester 1 as catalyst is described. By a simple basic workup of 2-halohydrins, optically active epoxides are obtained in high yield and with excellent enantiopurity (up to 99% ee). Ring-opening of oxiranes with phenoxides or sodium azide is investigated under different reaction conditions affording nonracemic 1,2-hydroxy ethers and 1,2-azido alcohols with excellent enantioselectivity
Highly Regioselective Ring Opening of Epoxides with Polymer Supported Phenoxide and Naphthoxide Anions
作者:B. Tamami、N. Iranpoor、R. Rezaei
DOI:10.1081/scc-200026220
日期:2004.1
Abstract Amberlite IRA‐400 supported phenoxide and naphthoxide anions are easily prepared. These polymer supported reagents that are highly air stable are used for the regioselective ringopening reactions of different epoxides to give aryl ether alcohols in high yields under mild reaction conditions.
A catalyst-free regio- and stereoselective ring-opening of epoxides with phenoxides has been carried out efficiently using polyethyleneglycol as the reaction medium to form the corresponding β-aryloxyalcohols in high yields at room temperature.