l-Threonine-derived phosphine-sulfonamide 4 was identified as the most efficient catalyst to promote enantioselective aza-Morita-Baylis-Hillman (MBH) reactions, affording the desired aza-MBH adducts with excellent enantioselectivities. Density functional theory (DFT) studies were carried out to elucidate the origin of the observed enantioselectivity. The importance of the intramolecular N-H⋯O hydrogen-bonding interaction between the sulfonamide and enolate groups was identified to be crucial in inducing a high degree of stereochemical control in both the enolate addition to imine and the subsequent proton transfer step, affording aza-MBH reactions with excellent enantioselectivity. © 2013 The Royal Society of Chemistry.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We are grateful for the generous financial support from King Abdullah University of Science and Technology to K.-W.H. and from the National University of Singapore and the Ministry of Education (MOE) of Singapore (R-143-000-494-112) to Y. L.
ASJC Scopus subject areas
- Organic Chemistry
- Physical and Theoretical Chemistry