An Efficient Recyclable Catalytic System for Asymmetric Dihydroxylation of Olefins

Ru Jiang, Yongqing Kuang, Xiaoli Sun, and Shengyong Zhang*
Department of Chemistry, Fourth Military Medical University, 710032 Xi’an, China. E-mail: syzhang@fmmu.edu.cn

Abstract
A recoverable and reusable catalytic system for asymmetric dihydroxylation of olefins was developed by using TentaGel-OsO₄ 1 and mono-quaternized bis-cinchona alkaloid chiral ligand 2 combined with ionic liquid [bmim]PF₆. Both the osmium and ligand could be recovered efficiently. It could be recycled ten times with only 0.5 mol% of 1 and 2.0 mol% of 2. The system is effective in the AD reactions of a range of olefins.

Key words: chiral ligand, TentaGel-OsO₄, ionic liquid, asymmetric dihydroxylation