The Use of Lewis Acids for Repairing Chemoselectivity of the Organocatalyzed Morita-Baylis-Hillman Reaction

A substantial improvement in the chemoselectivity of the Morita-Baylis-Hillman reaction was realized by adding a diimino- or diaminopyridine coordination site within the backbone of bis-imidazole organocatalysts and using Lewis acids situated at this coordination site. The optimal outcome of 90–95% selectivity was achieved by proper matching of the catalyst/additive pair, as well as their respective amount (0.4 equiv. of AgOAc per 1 equiv. of diaminopyridine-incorporating catalyst).