Synthesis of 2-Arylpiperidines by Palladium Couplings of Aryl Bromides with Organozinc Species Derived from Deprotonation of N-Boc-Piperidine

The organolithium species derived from proton abstraction of N-Boc-piperidine with s-BuLi and TMEDA can be transmetalated to the organozinc reagent, and this organometallic species can be coupled directly with aryl bromides in a Negishi-type reaction using palladium catalysis with the ligand tri-tert-butylphosphine (t-Bu3P-HBF4). The chemistry was applied to a very short synthesis of the alkaloid anabasine.