Palladium-catalyzed multi-acetoxylation of 1,3-disubstituted 1H-pyrazole-5-carboxylates via direct C(sp^2)-H or C(sp^3)-H bond activation  

作　　者：Jun Ding Ying Guo Ling-Yan Shao Fei-Yi Zhao Dao-Hua Liao Hong-Wei Liu Ya-Fei Ji 

机构地区：[1]School of Pharmacy,East China University of Science & Technology

出　　处：《Chinese Chemical Letters》2016年第10期1617-1621,共5页中国化学快报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.21176074 and 21476074);the Research Fund for the Doctoral Program of Higher Education of China(No.20130074110009)for financial support

摘　　要：A palladium-catalyzed multi-acetoxylation of 1,3-disubstituted 1H-pyrazole-5-carboxylate derivatives containing multiple potential reactive sites is described. Therein, the sequence of this process has been appropriately investigated. The protocol mainly provides the di- and tri-acetoxylated products for 1,3- diarylpyrazoles. Besides, it is found that the acetoxylation of C（sp3）-H bond is prior to that of C（sp2）-H bond under structurally competitive conditions.A palladium-catalyzed multi-acetoxylation of 1,3-disubstituted 1H-pyrazole-5-carboxylate derivatives containing multiple potential reactive sites is described. Therein, the sequence of this process has been appropriately investigated. The protocol mainly provides the di- and tri-acetoxylated products for 1,3- diarylpyrazoles. Besides, it is found that the acetoxylation of C（sp3）-H bond is prior to that of C（sp2）-H bond under structurally competitive conditions.

关 键 词：Palladium catalysisFunctionalized pyrazolesMulti-acetoxylationC-H activationMonodentate directing group 

分 类 号：O621.251[理学—有机化学]