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

Novel heterobimetallic catalysts possessing lithium alkoxide as Bronsted ba se have been developed. The catalysts were found to be effective in the dir ect asymmetric aldol reaction of less acidic dialkyl ketones as well as aro matic ketones, affording the aldol products in moderate yield and ee. Attem pts at diastereo- and enantioselective direct catalytic aldol reaction of e thyl ketone using small molecule catalysts are reported for the first time. (C) 2001 Published by Elsevier Science Ltd.