Synthesis of polymers containing chiral 1,2-diamine derivatives and their application to asymmetric reactions*
Shinichi Itsuno, Miyuki Takahashi, Yukihiro Arakawa, and Naoki Haraguchi
Department of Materials Science, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580, Japan
Abstract: Polymer-supported chiral 1,2-diamine derivatives have been prepared. The polymers containing free 1,2-diamine moiety were applied to enantioselective hydrogenation catalyst by combination with RuCl2-BINAP complex. Asymmetric hydrogenation of aromatic ketones was performed by means of the polymeric catalyst derived from these polymers to give the chiral secondary alcohols with high ee in quantitative conversion. The polymers containing 1,2-diamine monosulfonamide were applied to enantioselective transfer hydrogenation catalyst by combination with RuCl2-p-cymene complex. Asymmetric transfer hydrogenation of aromatic ketones was performed by means of the polymeric catalyst to afford the chiral secondary alcohols. A high level of enantioselectivities up to 99 % ee was attained in neat water by using the polymeric catalyst prepared from quaternary ammonium salt-type polymer support.
Keywords: polymer support; asymmetric catalysis; hydrogenation; transfer hydrogenation; aromatic ketones; RuCl2.
*Paper based on a presentation at the 12th International Conference on Polymers and Organic Chemistry 2006 (POC'06), 2-7 July 2006, Okazaki, Japan. Other presentations are published in this issue, pp. 1471-1582.