[EN] CATALYTIC ASYMMETRIC SYNTHESIS OF OPTICALLY ACTIVE alpha-HALO-CARBONYL COMPOUNDS<br/>[FR] SYNTHESE ASYMETRIQUE CATALYTIQUE DE COMPOSES DE DOLLAR G(A)-HALO-CARBONYLE OPTIQUEMENT ACTIFS
申请人:HALLAND NIS
公开号:WO2005080298A1
公开(公告)日:2005-09-01
A process for the catalytic asymmetric synthesis of an optically active compound of the formula (la) or (lb): wherein R is an organic group; X is halogen; Rl and R2which may the same or different represents H, or an organic group or Rl and R2 may be bridged together forming part of a ring system; R and R2 may be bridged together forming part of a ring system; with the provisio that R and Rl are different and R2, when different from H, is attached though a carbon-carbon bond, comprising the step of reacting a compound of the formula (2): with a halogenation agent in the presence of a catalytic amount of a chiral nitrogen containing organic compound.
General Approach to the Synthesis of the Chlorosulfolipids Danicalipin A, Mytilipin A, and Malhamensilipin A in Enantioenriched Form
作者:Won-jin Chung、Joseph S. Carlson、Christopher D. Vanderwal
DOI:10.1021/jo5000829
日期:2014.3.7
A second-generation synthesis of three structurally related chlorosulfolipids has been developed. Key advances include highly stereocontrolled additions to α,β-dichloroaldehydes, kinetic resolutions of complex chlorinated vinyl epoxide intermediates, and Z-selective alkene cross metatheses of cis-vinyl epoxides. This strategy facilitated the synthesis of enantioenriched danicalipin A, mytilipin A,
已开发出三种结构相关的氯硫脂的第二代合成方法。主要进展包括对 α,β-二氯醛的高度立体控制添加、复杂氯化乙烯基环氧化物中间体的动力学分辨率以及顺式乙烯基环氧化物的Z-选择性烯烃交叉复分解。该策略分别通过 9、8 和 11 个步骤促进了对映体富集的 danicalipin A、mytilipin A 和 malhamensilipin A 的合成。
Direct Organocatalytic Asymmetric α-Chlorination of Aldehydes
The direct organocatalytic enantioselective α-chlorination of aldehydes has been developed. The reaction proceeds for a series of different aldehydes with NCS as the chlorine source using easily available catalysts such as l-proline amide and (2R,5R)-diphenylpyrrolidine. The α-chloro aldehydes are obtained in up to 99% yield and up to 95% ee. The synthetic utility of the enantioselective α-chlorination
Chlorine, an atom economical auxiliary for asymmetric aldol reactions
作者:Shira D. Halperin、Robert Britton
DOI:10.1039/c3ob27462d
日期:——
An auxiliary strategy has been developed for asymmetricreactions of aldehydes in which the auxiliary itself is not chiral, but a single chlorine atom introduced via organocatalytic α-chlorination. The stereodirecting influence of the chlorine atom is then exploited prior to its removal by radical reduction. This strategy is demonstrated in the synthesis of several aldols (92–99% ee) and the natural