Chiral Zirconium Complex as Bronsted Base Catalyst in Asymmetric Direct-type Mannich Reactions

摘要

Development of efficient methods for preparation of optically active amino acids is one of the most important topics in synthetic organic chemistry. Asymmetric Mannich-type reactions have been recognized as one of the most efficient methods to provide optically active beta-amino esters, because new carbon-carbon bond formation and chiral induction are achieved at the same time in a single reaction step. Recently, several types of catalytic asymmetric Mannich-type reactions have been reported; among them, direct-type Mannich reactions are the most attractive from an atom economical point of view, because no stoichiometric amounts of bases or metals for pre-activation of carbonyl donors are required.