A New Multifunctional Heterobimetallic Asymmetric Catalyst for Michael Additions and Tandem Michael-Aldol Reactions

摘要

Although numerous asymmetric catalysts (chemzymes) have been developed utilizing nearly all the elements in the periodic table, the abilities of chemzymes have, in general, proven inferior to those of enzymes, probably because chemzymes have only onefunction with which to control asymmetric reactions. It is possible that multifunctional heterobimetallic asymmetric catalysts could compensate for the shortcomings of chemzymes by providing positive cooperation between different metals. Recently, for catalytic asymmetric carbon- carbon bond-forming reactions we introduced a new class of heterobimetallic complexes that consist of a rare earth metal center, an alkali metal center (Li. Na, K), and 2,2'dihydroxy-l,1'-binaphthyl (BINOL).