N-(trans-1-Propenyl)carbazole: an excellent dienophile for cation radical Diels–Alder cycloadditions

The efficient, regiospecific, and periselective Diels–Alder cycloadditions of N-(trans-1-propenyl)carbazole, a highly electron rich dienophile, to both acyclic and cyclic conjugated dienes is found to be induced by tris(4-bromophenyl)aminium hexachloroantimonate.