Catalytic Asymmetric Inverse-Electron-Demand Diels−Alder Reaction of N-Sulfonyl-1-Aza-1,3-Dienes

An efficient chiral Lewis acid-catalyzed inverse-electron-demand Diels−Alder reaction of 1-azadienes is described. This procedure is based on the combination of NiII-DBFOX complex as catalyst and the use of a metal-coordinating (8-quinolyl)sulfonyl moiety at the iminic nitrogen of the N-sulfonyl 1-aza-1,3-diene, providing highly functionalized piperidine derivatives in good yields with excellent endo-selectivity, and enantioselectivities typically in the range of 77−92% ee.