Stereoselective Tandem Synthesis of Pyrrolidine Derivatives under Gold Catalysis: An Asymmetric Synthesis of (-)-Lepadiformine A.

A Au-catalyzed tandem alkyne hydroamination/iminium ion formation/allylation reaction was developed for expedient access to pyrrolidine derivatives bearing a tetrasubstituted carbon stereocenter. The tandem reaction was successfully applied to a 12-step asymmetric synthesis of (-)-lepadiformine A, a marine cytotoxic tricyclic alkaloid.