Dehydrative Coupling of 1,1-Diarylalkenes and Cyclohexa-2,5-diene-1-carbaldehyde Derivatives Induced by a B(C 6 F 5 ) 3 -Initiated [1,2]-Alkyl Migration.

A four-step formal ipso allylation of benzoic acid derivatives involving a B(C 6 F 5 ) 3 -initiated and proton-catalyzed [1,2]-alkyl shift as part of a dehydrative coupling of cyclohexa-2,5-diene-1-carbaldehyde derivatives and 1,1-diarylalkenes is reported. By this, a series of allyl arenes can be regioselectively obtained from readily available benzoic acids in good yields.