Enantioselective synthesis of allenecarboxylates from phenyl acetates through CC bond forming reactions
摘要:
A variety of optically active 4,4-disubstituted allenecarboxylic acid methyl esters were prepared from simple alpha,alpha -disubstituted phenyl acetate through base treatment of the esters to generate ketenes, followed by successive Horner-Wadsworth-Emmons reaction. The transformation was further developed as a one-pot procedure with satisfactory yields and high enantioselectivity. (C) 2001 EIsevier Science Ltd. All rights reserved.
Pd-Catalyzed Regiodivergent Hydroesterification of Aryl Olefins with Phenyl Formate
作者:Wenlong Ren、Wenju Chang、Yang Wang、Jingfu Li、Yian Shi
DOI:10.1021/acs.orglett.5b01630
日期:2015.7.17
An effective Pd-catalyzed regiodivergent hydroesterification of aryl olefins with phenyl formate is described. Either linear or branched phenyl arylpropanoates can be obtained in good yields with high regioselectivities by the judicious choice of ligand without the use of toxic CO gas.
Disclosed are certain compounds according to the general formula (I)
and their use as flavoring and fragrancing compounds, as well as fragranced and flavored compositions comprising the compounds of formula (I), and methods for providing a flavor or fragrance to compositions and articles utilizing the compounds of formula (I).
Disclosed are certain compounds according to the general formula (I)
and their use as flavoring and fragrancing compounds, as well as fragranced and flavored compositions comprising the compounds of formula (I), and methods for providing a flavor or fragrance to compositions and articles utilizing the compounds of formula (I).
Described herein is the development of a visible-light-driven carbonylation of alkyl halides. The exploitation of visible light to activate Pd complexes and the use of formates to serve the dual role of a CO surrogate and a phenoxide source allow the preparation of esters in moderate to good yields. Its relatively mild reaction conditions and the ability to perform this transformation without direct
本文描述了可见光驱动的卤代烷羰基化的发展。利用可见光激活 Pd 配合物,并使用甲酸盐发挥 CO 替代物和酚盐源的双重作用,可以以中等至良好的产率制备酯。其相对温和的反应条件以及无需直接处理有毒CO气体即可进行这种转化的能力,为从烷基卤化物中获取酯提供了一种实用的方法。
Organocatalytic enantioselective decarboxylative protonation of α-alkyl-α-aryl malonate monoesters
enzymatic enantioselectivedecarboxylative protonation (EDP), the corresponding chemocatalytic reactions of acyclic malonic acid derivatives remain challenging. Herein, we developed a biomimetic EDP of α-alkyl-α-aryl malonate monoesters using a chiral 1,2-trans-diaminocyclohexane-based N-sulfonamide as an organocatalyst. The method demonstrates excellent chemical yields, good enantioselectivity, mild reaction