有機触媒を利用するエナミン機構に基づく反応：アルドラーゼ抗体から低分子のアミノ酸およびアミン触媒まで

Abstract

Enamines are key intermediates in both organic chemistry and enzyme catalysis. Natural aldolase enzymes form an enamine intermediate from aldehydes and ketones in order to catalyze aldol reactions under mild ambient conditions. We have developed man-made aldolase catalytic antibodies and small peptides that catalyze aldol reactions, in which catalyst molecules form enamines from aldehydes and ketones in situ, like natural aldolase enzymes do. Through these studies, we have also developed small amine- and amino acid-catalyzed bond-forming reactions that use an enamine mechanism and that can be performed under mild ambient conditions. These low molecular weight amines form enamine intermediates in situ and the enamine reacts with electrophiles to afford products with high diastereo- and enantioselectivities. Our organocatalytic methodologies include catalytic asymmetric aldol, Mannich, Michael, and Diels-Alder reactions. Our catalysts, from aldolase antibodies to small organic amine and amino acid catalyst molecules, emulate many of the features of nature's enzymes.