1. Laboratory of Asymmetric Synthesis, College of Chemistry and Environmental Engineering Chongqing University of Arts and Sciences 319 Honghe Ave., Yongchuan Chongqing 402160 P.R. China
2. School of Chemistry and Chemical Engineering Chongqing University of Science and Technology Chongqing 402160 P.R. China
3. Present address: College of Pharmacy Harbin Medical University Harbin 150081 China