Synthesis 2015; 47(14): 2113-2124
DOI: 10.1055/s-0034-1379914
paper
© Georg Thieme Verlag Stuttgart · New York

Phosphine Oxide Catalyzed, Tetrachlorosilane-Mediated Enantioselective Direct Aldol Reactions of Thioesters

Sergio Rossi*
Dipartimento di Chimica, Universita degli Studi di Milano, via Golgi 19, 20133 Milano, Italy   Email: sergio.rossi@unimi.it
,
Rita Annunziata
Dipartimento di Chimica, Universita degli Studi di Milano, via Golgi 19, 20133 Milano, Italy   Email: sergio.rossi@unimi.it
,
Franco Cozzi
Dipartimento di Chimica, Universita degli Studi di Milano, via Golgi 19, 20133 Milano, Italy   Email: sergio.rossi@unimi.it
,
Laura Maria Raimondi
Dipartimento di Chimica, Universita degli Studi di Milano, via Golgi 19, 20133 Milano, Italy   Email: sergio.rossi@unimi.it
› Author Affiliations
Further Information

Publication History

Received: 09 February 2015

Accepted after revision: 24 March 2015

Publication Date:
13 May 2015 (online)


Abstract

The stereoselective direct aldol reaction of S-phenyl thioesters and aromatic aldehydes promoted by tetrachlorosilane was realized for the first time; the proposed mechanism involves the formation of a chiral cationic hypervalent silicon species and requires the presence of catalytic amounts of a Lewis base, like a chiral phosphine oxide. The reaction affords syn β-hydroxy thioesters as major isomers in good yields, high diastereoselectivity (up to 99:1), and up to 92% enantiomeric excess. The absolute configuration of the major isomer was established by converting the product into the corresponding β-hydroxy ester. The scope of the reaction was also investigated by employing differently substituted thioesters in combination with different aromatic aldehydes.

Supporting Information