Orchestrated triple C-H activation reactions using two directing groups: rapid assembly of complex pyrazoles
Weibo Yang1, Shengqing Ye, Dewey Fanning
1Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA).
Abstract:
A sequential triple C-H activation reaction directed by a pyrazole and an amide group leads to the well-controlled construction of sterically congested dihydrobenzo[e]indazole derivatives. This cascade reaction demonstrates that the often problematic competing C-H activation pathways in the presence of multiple directing groups can be harvested by design to improve step economy in synthesis. Pyrazole as a relatively weak coordinating group is shown to direct Csp3-H activation for the first time.
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