Direct Regioselective [3 + 2] Cycloaddition Reactions of Masked Difluorodiazoethane with Electron-Deficient Alkynes and Alkenes: Synthesis of Difluoromethyl-Substituted Pyrazoles

Jun-Liang Zeng; Zhen Chen; Fa-Guang Zhang; Jun-An Ma

doi:10.1021/acs.orglett.8b01854

Direct Regioselective [3 + 2] Cycloaddition Reactions of Masked Difluorodiazoethane with Electron-Deficient Alkynes and Alkenes: Synthesis of Difluoromethyl-Substituted Pyrazoles

Org Lett. 2018 Aug 3;20(15):4562-4565. doi: 10.1021/acs.orglett.8b01854. Epub 2018 Jul 17.

Authors

Jun-Liang Zeng¹, Zhen Chen¹, Fa-Guang Zhang¹, Jun-An Ma¹

Affiliation

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

PMID: 30014703
DOI: 10.1021/acs.orglett.8b01854

Abstract

Phenylsulfone difluorodiazoethane (PhSO₂CF₂CHN₂), an easy-to-prepare and bench-stable masked CF₂-building block, has been developed. The synthetic utility of this reagent is demonstrated by a direct regioselective [3 + 2] cycloaddition with electron-deficient alkynes and alkenes. This protocol enables facile construction of an array of difluoromethyl-substituted pyrazoles in good to high yields under mild reaction conditions.

Publication types

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