Palladium-catalyzed multi-acetoxylation of 1,3-disubstituted 1H-pyrazole-5-carboxylates via direct C(sp2)H or C(sp3)H bond activation
作者:Jun Ding、Ying Guo、Ling-Yan Shao、Fei-Yi Zhao、Dao-Hua Liao、Hong-Wei Liu、Ya-Fei Ji
DOI:10.1016/j.cclet.2016.04.007
日期:2016.10
1,3-disubstituted 1 H -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(sp 3 ) Hbond is prior to that of C(sp 2 ) Hbond under structurally