A facile stereoselective synthesis of α-glycosyl ureas

alpha-Glycosyl ureas can be synthesised directly from tetra-O-benzyl glycosyl azides and isocyanates, using a one-pot procedure that is simple and general in scope. The benzyl protecting groups are easily removed from the urea products by catalytic hydrogenation. The synthesised alpha-glycosyl ureas represent a new class of neo-glycoconjugates with the potential of being resistant towards carbohydrate processing enzymes.