Candida Rugosa lipase-catalyzed kinetic resolution of β-hydroxy-β-arylpropionates and δ-hydroxy-δ-aryl-β-oxo-pentanoates
摘要:
A simple and convenient method was reported for the preparation of optically active beta-hydroxy-beta-arylpropionates, delta-hydroxy-delta-aryl-beta-oxo-pentanoates and their butyryl derivatives via CRL-catalyzed hydrolysis. The optically active products are potential precursors of some chiral pharmaceuticals and natural products. (C) 2005 Elsevier Ltd. All rights reserved.
Visible-Light-Driven, Metal-Free Divergent Difunctionalization of Alkenes Using Alkyl Formates
作者:Ming Zheng、Jing Hou、Le-Wu Zhan、Yan Huang、Ling Chen、Li-Li Hua、Yan Li、Wan-Ying Tang、Bin-Dong Li
DOI:10.1021/acscatal.0c04332
日期:2021.1.15
difunctionalization of alkenes has received considerable attention as an efficient and straightforward way to increase molecular complexity. However, examples of the difunctionalization of alkenes initiated by the intermolecular addition of alkoxycarbonyl radicals providing substituted alkanoates are still rare. Herein, we present the visible light-driven metal-free divergent difunctionalization of alkenes triggered
A General Method for the Formation of Zinc Enolate Equivalents from Iodoacetates by Diisopropylzinc-Iodine Exchange Reaction: Preparation of<b><i>β</i></b>-Hydroxy Esters
作者:Itaru Sato、Yoshiko Takizawa、Kenso Soai
DOI:10.1246/bcsj.73.2825
日期:2000.12
Diisopropylzinc is found to be a highly efficient reagent for the formation of zinc enolate equivalents from various iodoacetates via iodine-zinc exchange reaction at roomtemperature, affording β-hydroxy esters in highyields by the reaction with aldehydes and ketones.
(R)-(+)-N-Methylbenzoguanidine ((R)-NMBG) catalyzed acylative kinetic resolution of racemic 3-hydroxy-3-aryl-propanoates
作者:Akira Yamada、Kenya Nakata
DOI:10.1016/j.tetlet.2016.09.014
日期:2016.10
cyclohexane carboxylic anhydride under mild reaction conditions. A tert-butyl ester moiety is necessary to achieve a high selectivity. The effects of the substituents on the aromatic rings of the substrates were systematically investigated, and diverse substrates participated in the reaction with good s-values (>20) irrespective of the type of substituents and their patterns, except for o-methoxy group
Optically active 3-aryl-3-hydroxyesters of high enantiomeric excess (80–92% e.e.) are obtained by the reduction of 3-aryl-3-oxoesters with lithiumborohydride which has been chirally modified with N,N′-dibenzoylcystine and t-butyl alcohol.
It was found that thioboronite reacted with substituted ketene (produced from α-haloacyl halide and zinc dust) and carbonyl compounds to give the corresponding α-substituted β-hydroxyalkanethioates in good yields. Also, it was established that β-hydroxyalkanoates were obtained in good yields by utilizing aluminum alkoxide in place of thioboronite in the above reaction.