Summary: Formic acid is shown to be a particularly effective hydrogen donor for the rapid removal of peptide benzyl and benzyloxycarbonyl protecting groups by catalytic transfer hydrogenation.Sir: Catalytic transfer hydrogenation has been shown to be a useful procedure for the removal of benzyl and benzyloxycarbonyl protecting groups in peptide synthesis.1-4 Good yields of deprotected products have been obtained under relatively mild conditionsusing both. © 1979, American Chemical Society. All rights reserved.