Direct catalytic asymmetric aldol reactions promoted by novel heterobimetallic catalysts possessing strong Brønsted base: a new strategy for the development of Lewis acid–Brønsted base bifunctional catalysts

Novel heterobimetallic catalysts possessing lithium alkoxide as Brønsted base have been developed. The catalysts were found to be effective in the direct asymmetric aldol reaction of less acidic dialkyl ketones as well as aromatic ketones, affording the aldol products in moderate yield and ee. Attempts at diastereo- and enantioselective direct catalytic aldol reaction of ethyl ketone using small molecule catalysts are reported for the first time.