Zn(II)-Catalyzed Synthesis of Piperidines from Propargyl Amines and Cyclopropanes

The reaction of benzyl-protected propargyl amines and 1,1-cyclopropane diesters in the presence of catalytic Zn(NTf2)2 allows access to highly functionalized piperidines in excellent yields. The process proceeds via a tandem cyclopropane ring-opening/Conia−ene cyclization.