Nickel-Catalyzed Deallylation for Sustainable Solution and Solid-Phase Peptide Synthesis

We report a one-step, nickel-catalyzed allyl/alloc deprotection compatible with solid-phase peptide synthesis (SPPS) to address the reliance on costly palladium conditions and limited on-resin compatibility of base-metal alternatives. Our two-component system employs an air-stable Ni(PPh 3 ) 2 Br 2 precatalyst and NH 3 BH 3 reductant and operates rapidly in SPPS-compatible solvents under inertion. This protocol efficiently and chemoselectively deprotects allyl- and alloc-protected amino acids, small molecules, and peptides in solution and has been extended to on-resin deprotection, showing promise for SPPS applications.