Highly Regio‐ and Enantioselective Nitroso Diels−Alder Reaction of 1,3‐Diene‐1‐carbamates Catalyzed by Chiral N,N′‐Dioxide/Copper(II) Complex

A chiral N,N'-dioxide/Copper(II) complex-catalyzed highly regio- and enantioselective nitroso Diels-Alder (NDA) reaction of 2-nitrosopyridines with 1,3-diene-1-carbamates was described. A series of 3,6-dihydro-1,2-oxazines were obtained in good to excellent yields and ee values. On the basis of the control experiments, ESI-MS analysis and the absolute configuration of the product, a possible transition state model was proposed to explain the stereocontrol.