ASYMMETRIC HYDROGENATION OF ALPHAAAMINOACRYLIC ACID DERIVATIVE

摘要

PURPOSE:To prepare an optically active alpha-amino acid having high optical purity, easily, in high yield, by the asymmetric hydrogenation of an alpha-aminoacrylic acid derivative in the presence of a specific cationic rhodium complex as a catalyst. CONSTITUTION:An alpha-aminoacrylic acid derivative of formula I (R<1>,<3> are H, alkyl, or aryl; R<2> is alkyl or aryl) is subjected to the asymmetric hydrogenation reaction with hydrogen gas (0.5-3atm partial pressure), in the presence of a cationic rhodium complex catalyst of formula II (R<4> is H, alkyl, aryl or alkoxy; X<-> is inorganic anion), in a solvent such as alcohol, ether, etc., at -20-+50 deg.C, pref. at room temp. Addition of an amine such as triethylamine to the reaction system further improves the optical purity of the product.