Use of a Traceless Activating and Directing Group for the Construction of Trifluoromethylpyrazoles: One-Pot Transformation of Nitroolefins and Trifluorodiazoethane

Zhen Chen; Yan Zheng; Jun-An Ma

doi:10.1002/anie.201700955

Use of a Traceless Activating and Directing Group for the Construction of Trifluoromethylpyrazoles: One-Pot Transformation of Nitroolefins and Trifluorodiazoethane

Angew Chem Int Ed Engl. 2017 Apr 10;56(16):4569-4574. doi: 10.1002/anie.201700955. Epub 2017 Mar 22.

Authors

Zhen Chen¹, Yan Zheng¹, Jun-An Ma¹

Affiliation

¹ Department of Chemistry, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, Collaborative, Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, P. R. of China.

PMID: 28328171
DOI: 10.1002/anie.201700955

Abstract

We disclose an efficient one-pot transformation of trifluorodiazoethane and higher perfluorinated homologues with various nitroolefins. This method takes advantage of the nitro group as a traceless activating and directing group (TADG) that is released in the aromatization step to produce 4-substituted 3-perfluoroalkyl pyrazoles with complete regioselectivity. The potential of this method is further demonstrated by the synthesis of penthiopyrad.

Keywords: diazo compounds; nitroolefins; pyrazoles; regioselectivity; traceless directing groups.

Publication types

Research Support, Non-U.S. Gov't