DDQ-catalyzed oxidative α-allylation of isochromans under aerobic conditions.

The allylation of isochromans at the α-position aerobic DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) catalysis is described. This process involves the DDQ oxidation of various isochromans under mild conditions to generate oxocarbenium intermediates, which are effectively stabilized in equilibration in the presence of acid before undergoing allylation. Molecular oxygen and -butyl nitrite are employed as an environmentally benign oxidant and mediator, respectively, in the catalytic cycle. The transformation of an allylated product to biologically active molecules has also been successfully demonstrated.