1. Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China, Fax: +86‐21‐64166128
2. Wisdom Pharmaceutical Co., Ltd., 601 East, Xiu‐shan Road, Haimen, Jiangsu Province 226100, China
3. College of Chemistry and Chemistry Engineering, Donghua University, 2999 North Renmin Lu, Shanghai 201620, China