Catalytic Enantioselective Aldol Reactions of Unprotected Carboxylic Acids under Phosphine Oxide Catalysis. Issue 48 (5th November 2018)

• Record Type: Journal Article
• Authors: Kotani, Shunsuke; Yoshiwara, Yusaku; Ogasawara, Masamichi; Sugiura, Masaharu; Nakajima, Makoto
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 48(2018)
• Page Start: 15877
• Page End: 15881
• Publication Date: 2018-11-05
• Subjects: aldol reaction -- carboxylic acids -- hypervalent silicon -- organocatalysis -- phosphine oxides; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201810599
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The first catalytic enantioselective aldol reaction of various unprotected carboxylic acids is described. In the presence of a chiral bis(phosphine oxide) as a Lewis base catalyst, carboxylic acids were activated with silicon tetrachloride to form the corresponding bis(trichlorosilyl)enediolates in situ, which subsequently underwent an aldol reaction with an aldehyde or a ketone to produce β‐hydroxycarboxylic acids in high enantioselectivities of up to 92 % ee . Abstract : Various unprotected carboxylic acids undergo enantioselective aldol reactions in the presence of a chiral phosphine oxide as a Lewis base catalyst. The carboxylic acids were activated with silicon tetrachloride to form the bis(trichlorosilyl)enediolates in situ, which subsequently underwent an aldol reaction with an aldehyde or a ketone to produce β‐hydroxycarboxylic acids in high enantioselectivities of up to 92 % ee .