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 Ni-II-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 endoselectivity, and enantioselectivities typically in the range of 77-92% ee.