Synfacts 2005(1): 0125-0125  
DOI: 10.1055/s-2005-872192
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Protic Functionality-Tolerant Decarboxylative Thioester syn-Aldol Reactions

Contributor(s): Mark Lautens, Andrew Martins
D. Magdziak, G. Lalic, H. M. Lee, K. C. Fortner, A. D. Aloise, M. D. Shair*
Harvard University, Cambridge, USA
Further Information

Publication History

Publication Date:
21 September 2005 (online)

Significance

Traditional aldol reactions use quite basic conditions; often requiring protecting groups on protic functionalities. Aldol reactions under neutral conditions avoid this requirement, and an efficient precursor for such reactions is methyl malonic acid half thioester (MeMAHT). In the presence of Cu(OTf)2, (R,R)-Phbox, and an enolizable aldehyde (which can contain unprotected protic functional groups), MeMAHT undergoes syn-aldol reaction in good yield, with excellent enantioselectivity and moderate to excellent dia­stereoselectivity. The reaction is insensitive to other reactive functionalities including methyl ketones, acetals, ketals, and acid-sensitive indole-containing aldehydes.