A comparative study of high pressure versus other activation modes in the asymmetric Michael reaction of chiral imines

Abstract

The Michael reaction of chiral imines under neutral conditions has emerged as an efficient method for the elaboration of quaternary carbon centers in the alpha position relative to a carbonyl group. It was established early on that this reaction could be accelerated by thermal activation without altering its remarkable features, namely its high regio- and stereoselectivities, Michael adducts being obtained typically in high yield and with 90–98% ee. In this article, a comparative study of high-pressure activation versus thermal, microwave or catalytic activation of this reaction will be reported, highlighting the specificity of each activation mode.

Keywords:

• Asymmetric synthesis
• Michael reaction
• High pressure
• Microwave
• Catalysis
• Activation mode

Acknowledgements

Pr Jean d'Angelo (CEP, Université Paris Sud, France), Gérard Hamel and Jean-Claude Chervin (Université Paris VI) for their valuable technical assistance and stimulating discussions. Dr Robert Dodd (CNRS, Gif sur Yvette, France) and Elisabeth Fallon (Le Plessis Robinson, France) for their improvements to the manuscript.