Synthesis, characterization and application of Ru(BINAP)(Acac)(MNAA)(MeOH), a highly effective catalyst for the asymmetric hydrogenation of 2-(6′-methoxynaphth-2′-yl)acrylic acid

摘要

Ru(S-BINAP)(Acac)(MNAA)(MeOH) (1) (where MNAA (2) = 2-(6′-methoxynaphth-2′-yl)acrylate anion), a highly effective catalyst for the asymmetric hydrogenation of 2-(6′-methoxynaphth-2′-yl)acrylic acid (3), was isolated from a dichloromethane/methanol (vol./vol. = 1/4) solution of Ru(S-BINAP)(Acac)2 and excess of 2-(6′-methoxynaphth-2′-yl)acrylic acid after the solution was exposed to visible light for 2 weeks. On side by side comparison studies, the rate of the hydrogenation of 3 catalyzed by 1 was found to be substantially faster than the same reaction catalyzed by Ru(S-BINAP)(OAc)2. The molecular structure of 1 was unambiguously characterized by single crystal X-ray diffraction.