Easy Access to 2,4-Disubstituted Cyclopentenones by a Gold(III)-Catalyzed A3-Coupling/Cyclization Cascade.

An efficient and convenient synthesis of 2,4-disubstituted cyclopentenones has been achieved through a Au(III)-catalyzed isomerization-A3-coupling/cyclization cascade. A possible mechanism involving an initial Au(III)-catalyzed isomerization, A3-type coupling, and cyclization via an enol intermediate is postulated.