Copper( i )/TF-BiphamPhos catalyzed asymmetric nitroso Diels–Alder reaction

A highly efficient enantioselective nitroso Diels-Alder reaction of 6-methyl-2-nitroso pyridine with various 1,3-dienes was successfully developed using a Cu(i)/(S)-TF-BiphamPhos complex as the catalyst. For most of the cyclic dienes, synthetically important heterocyclic 3,6-dihydro-1,2-oxazines were obtained in high yields with excellent regio-, diastereo- and enantioselectivities. Acyclic 2-silyloxy-1,3-diene also worked well in the reaction.