Domino Heck-C-H activation reaction of unsymmetrically substituted [3]cumulene.

The Heck reaction of an unsymmetrically substituted [3]cumulene has been investigated. Although a carbonyl conjugated alkene is present, the arylpalladium species selectively inserts into the C3-4 double bond, and a subsequent C-H activation reaction with a neighboring phenyl group gives the indene derivatives with a tetrasubstituted olefin moiety.