1. Department of Chemistry, Norwegian University of Science and Technology (NTNU), NO‐7491 Trondheim, Norway;2. Department of Chemistry, Faculty of Science, University of Troms?, NO‐9037 Troms?, Norway
Abstract:
A series of N‐sulfinyl dienophiles 1c‐i has been screened in asymmetric hetero‐Diels‐Alder reactions using chiral bis(oxazoline)copper(II) and ‐zinc(II) triflates. The survey pointed out N‐sulfine 1c (R ? P(?O)(OPh)2) as the most promising N‐sulfine regarding yield and stereoselectivity (up to 97% ee). The relative configurations, and in one case the absolute configuration, of the HDA adducts were established by X‐ray analysis.
