Catalytic enantioselective synthesis of α-aryl α-hydrazino esters and amides

Catalysts generated by combinations of Pd(TFA)2 and pyridine-hydrazone ligands have allowed the asymmetric 1,2-addition of aryl boronic acids to N-carbamoyl (Cbz and Fmoc) protected glyoxylate-derived hydrazones, yielding α-aryl α-hydrazino esters/amides in high enantioselectivities. Subsequent removal of the carbamoyl moiety affords key building blocks en route to hydrazinopeptides, N-aminopeptides and peptidomimetics thereof.