Palladium-catalyzed late-stage mono-aroylation of the fully substituted pyrazoles via aromatic C–H bond activation

• Published in: Chinese chemical letters Vol. 30; no. 3; pp. 702 - 706
• Main Authors: Chen, Miao-Miao, Shao, Ling-Yan, Lun, Li-Jun, Wu, Yu-Liang, Fu, Xiao-Pan, Ji, Ya-Fei
• Format: Journal Article
• Language: English
• Published: NEW YORK Elsevier B.V 01.03.2019; Elsevier; School of Pharmacy, East China University of Science&Technology, Shanghai 200237, China%Shandong Keyuan Pharmaceutical Co., Ltd., Shandong Shanghe Economic Development Zone, Jinan 251601, China
• Subjects: AroYlation; C[sbnd]H bond activation; Chemistry; Chemistry, Multidisciplinary; Cyclopalladated intermediate; Fully substituted pyrazoles; Late-stage functionalization; Palladium-catalysis; Physical Sciences; Science & Technology; AroYlation; Cyclopalladated intermediate; Fully substituted pyrazoles; CH bond activation; Late-stage functionalization; Palladium-catalysis; FRIEDEL-CRAFTS ACYLATION; OXIDATIVE ACYLATION; C-H bond activation; ALDEHYDES; DIRECT ACCESS; FUNCTIONALIZATION; BIOLOGICAL EVALUATION; ALPHA-OXOCARBOXYLIC ACIDS; DECARBOXYLATIVE ORTHO-ACYLATION; O-METHYL OXIMES; DERIVATIVES; C > H bond activation
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2018.09.022

A Pd-catalyzed late-stage aroylation of 4-methyl-1,5-diaryl-1 H-pyrazole-3-carboxylates has been developed via direct Csp2−H bond activation with exclusive site-selectivity, broad substrate scope and good functional group tolerance. [Display omitted] The palladium-catalyzed late-stage aroylation of 4-methyl-1,5-diaryl-1H-pyrazole-3-carboxylates has been developed via direct and exclusive mono-Csp2H bond activation with broad substrate scope and good functional group tolerance. A dual-core dimeric palladacycle is confirmed by X-ray single crystal crystallography, and probably serves as an active species in the catalytic cycle.