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(PPh3)2Br2 precatalyst and NH3BH3 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.
Aguilera et al. (Tue,) studied this question.