The protease-catalyzed synthesis of amino acid ester-carbohydrate conjugate
s as glycopeptide analogues has been achieved in a highly regioselective an
d carbohydrate-specific manner using amino acid vinyl ester acyl donors and
minimally or completely unprotected carbohydrate acyl acceptors, which tog
ether probed active sites of proteases to reveal yield efficiencies that ar
e modulated by the carbohydrate C-2 substituent, and that may be exploited
to allow selective one-pot syntheses.