1. Department of Chemistry; Innovative Drug Research Center Shanghai University; Shanghai 200444 P. R. China
2. Laboratory for Microstructures; Instrumental Analysis and Research Center of Shanghai University; Shanghai 200444 P. R. China
3. Key Laboratory of Organofluorine Chemistry; Shanghai Institute of Organic Chemistry Chinese Academy of Sciences; Shanghai 200032 P. R. China
4. Key Laboratory of Synthetic Organic Chemistry of Natural Substances; Shanghai Institute of Organic Chemistry Chinese Academy of Sciences; Shanghai 200032 P. R. China
5. State Key Laboratory of Organometallic Chemistry; Shanghai Institute of Organic Chemistry Chinese Academy of Sciences; Shanghai 200032 P. R. China