1. School of Pharmaceutical Sciences Key Laboratory of Bioorganic Phosphorous Chemistry & Chemical Biology (Ministry of Education) Tsinghua University Beijing 100084 P. R. China
2. The Eighth Affiliated Hospital Sun Yat‐sen University Shenzhen Guangdong 518033 P. R. China
3. Department of Chemistry Renmin University of China Beijing 100872 P. R. China
4. Department of Chemistry Capital Normal University Beijing 100048 P. R. China