Straightforward Approach towards Piperidines via Stille Coupling and Subsequent 1,4-Addition of Amines

Substituted 4-piperidones are easily obtained from alkynes via molybdenum-catalyzed regioselective hydrostannation and subsequent Stille-coupling of the vinyl stannanes obtained with (alpha),(beta)-unsaturated acyl chlorides. The resulting divinylketones can undergo a double 1,4-addition of amines giving rise to the required 4piperidones. The best results are obtained if the Stille couplings and the 1,4-additions are combined in a one-pot procedure.