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Orchestrated triple C-H activation reactions using two directing groups: rapid assembly of complex pyrazoles.

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.

SUBMITTER: Yang W

PROVIDER: S-EPMC4426881 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature

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Orchestrated triple C-H activation reactions using two directing groups: rapid assembly of complex pyrazoles.

Yang Weibo W Ye Shengqing S Fanning Dewey D Coon Timothy T Schmidt Yvonne Y Krenitsky Paul P Stamos Dean D Yu Jin-Quan JQ

Angewandte Chemie (International ed. in English) 20150116 8

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. ...[more]

PMID: 25641121

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