已经开发了通过 CC 键裂解的 Cu 催化的简单酮的有氧氧化酯化。各种常见的酮,甚至是惰性的芳基长链烷基酮,都被选择性地转化为酯。该反应耐受多种醇,包括伯醇和仲醇、保留构型的手性醇、缺电子酚以及各种天然醇。使用廉价的铜催化剂、广泛的基材范围以及中性和露天条件使该协议非常实用。(18)O 标记实验表明,在这种转化过程中发生了氧化作用。初步机制研究表明,该过程主要涉及两条新途径。
SuperQuat 5,5-dimethyl-4-iso-propyloxazolidin-2-one as a mimic of Evans 4-tert-butyloxazolidin-2-one
作者:Steven D. Bull、Stephen G. Davies、A. Christopher Garner、Dennis Kruchinin、Min-Suk Key、Paul M. Roberts、Edward D. Savory、Andrew D. Smith、James E. Thomson
DOI:10.1039/b605244d
日期:——
The incorporation of a gem-dimethyl group at the 5-position of a chiral oxazolidinone biases the conformation of the adjacent C(4)-stereodirecting group such that the gem-dimethyl-4-iso-propyl combination mimics a C(4)-tert-butyl group, providing higher levels of stereocontrol than a simple 4-iso-propyloxazolidinone. The generality of this principle is demonstrated with applications in stereoselective enolate alkylations, kinetic resolutions, Diels–Alder cycloadditions and Pd-catalysed asymmetric acetalisation reactions.
Photochemically Immobilized 4-Methylbenzoyl Cellulose as a Powerful Chiral Stationary Phase for Enantioselective Chromatography
作者:Eric Francotte、Dan Huynh、Tong Zhang
DOI:10.3390/molecules21121740
日期:——
prepare chiralstationaryphases (CSPs) for enantioselectivechromatography. The immobilization was achieved by simple irradiation of the polysaccharide derivative with ultraviolet light after coating on a silica gel support. The influence of parameters such as irradiation time and solvent on immobilization effectiveness were investigated. The performance of the prepared immobilized phases were evaluated
New optical resolution method based on the formation of a solid solution. Optical resolution of racemic 1-(4-methylthiophenyl)-2-phenylpropan-1-one by co-crystallization with (+)-1-(4-methoxyphenyl)-2-phenylpropan-1-one.
作者:Chantal Garcia、André Collet
DOI:10.1016/s0957-4166(00)80275-x
日期:1992.1
solid solution containing 8% of S-(+)-2; the latter was isolated in enantiomerically pure form by column chromatography. This simple optical resolution procedure may represent an alternative to chiral HPLC for the preparation of small quantities of pure enantiomers, and the determination of their absolute configurations.
Convenient Method for the Preparation of Carboxylic Esters Using (Chloromethylene)dimethylammonium Chloride
作者:Hitoshi Nagao、Makoto Michida、Teruaki Mukaiyama
DOI:10.1080/00397910802109299
日期:2008.8.29
Abstract (Chloromethylene)dimethylammonium chloride (Vilsmeierreagent) works as an efficient condensation reagent in the formation of carboxylic esters from carboxylic acids and alcohols under mild conditions in a one-pot procedure. Secondary alcohols are converted successively into the corresponding esters in moderate to high yields with inversion of configurations.