The first catalytic enantioselective aldol reaction of various unprotected carboxylic acids is described. In the presence of ac hiral bis(phosphine oxide) as aL ewis 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 aketone to produce b-hydroxycarboxylic acids in high enantioselectivities of up to 92 %ee. Scheme 1. Enantioselective aldol reactions of carboxylic acids.[*] Dr.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Asymmetric catalytic transformations of N-unprotected cyclic carboxyimides such as succinimides, hydantoins, oxazolidinediones, and glitazones, is a powerful way of directly accessing variety of biologically valuable chiral compounds. Herein, a bis(trichlorosilyl) nucleophilic intermediate formed from cyclic carboxyimides was reacted with aldehydes via (S)-SEGPHOS dioxide (SEGPHOSO), proceeding the aldol reaction in highly enantioselective fashion through a cyclic transition state. Furthermore, N-unprotected carboxyimides were chemoselectively activated, even in the presence of N-alkylated carboxyimides, to undergo stereoselective and chemoselective aldol reactions via in situ silicon tetrachloride activation. The functionalized cyclic carboxyimides is readily derived to the several synthetic units derivatization to various chiral building blocks without unnecessary protection/deprotection steps.

The first catalytic enantioselective aldol reaction of various unprotected carboxylic acids is described. In the presence of ac hiral bis(phosphine oxide) as aL ewis 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 aketone to produce b-hydroxycarboxylic acids in high enantioselectivities of up to 92 %ee. Scheme 1. Enantioselective aldol reactions of carboxylic acids.[*] Dr.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.