两种铜盐(Cu(CF 3 CO 2)2和IMesCuCl)被鉴定为是地球上丰富的,廉价的但有效的金属催化剂,与重氮丙二酸酯一起用于各种环氧化物的化学/区域选择性和立体定向脱氧反应,并具有常见的官能团耐受性(烯烃,酮,酯,对甲氧基苄基,苄基,叔丁基二甲基甲硅烷基和三异丙基甲硅烷基)。特别是,空前的区域选择性使二环氧化物首次单脱氧为烯基环氧化物。密度泛函理论的机理研究表明,脱氧是通过折叠游离的叶立德而发生的,不利于通过可能的氧杂环丁烷的环还原而产生的直观途径。
Selective oxidation with t-butyl hydroperoxide and aluminium reagents
作者:Kazuhiko Takai、Koichiro Oshima、Hitosi Nozaki
DOI:10.1016/s0040-4039(00)77778-1
日期:1980.1
Stereoselective epoxidation of allylic alcohols is achieved with organoaluminium peroxides. Transformation of secondary alcohols to ketones with same reagents is also disclosed.
An efficient catalytic asymmetric synthesis of the CPB pheromone [(S)-1,3-dihydroxy-3,7-dimethy1-6-octen-2-one] and its enantiomer was accomplished with 99% ee and in gram quantities from geraniol. The key steps in this procedure involve Sharpless asymmetric epoxidation and recrystallization of the 4-bromobenzoate from the CPB pheromone to improve its enantiomeric purity. Furthermore, the absolute configuration of the CPB pheromone enantiomer was confirmed as (R) for the first time by the X-ray crystallographic structure of its benzoate. (C) 2014 Elsevier Ltd. All rights reserved.
Enantioselective Syntheses of <i>trans</i>-3,4-Difluoropyrrolidines and Investigation of Their Applications in Catalytic Asymmetric Synthesis
作者:Charles M. Marson、Robert C. Melling
DOI:10.1021/jo0513414
日期:2005.11.1
Asymmetric Syntheses of enantiopure trans-3,4-difluoropyrrolidines have been prepared by the introduction of fluorine at both centers in a single operation; asymmetric epoxidations and additions to benzaldehyde were conducted using catalysts whose chirality depends on organofluorine asymmetry.