Cleavage of C(sp3)-F Bonds in Trifluoromethylarenes Using a Bis(NHC)nickel(0) Complex

Hiroaki Iwamoto; Hiroto Imiya; Masato Ohashi; Sensuke Ogoshi

doi:10.1021/jacs.0c09639

Cleavage of C(sp³)-F Bonds in Trifluoromethylarenes Using a Bis(NHC)nickel(0) Complex

J Am Chem Soc. 2020 Nov 11;142(45):19360-19367. doi: 10.1021/jacs.0c09639. Epub 2020 Oct 28.

Authors

Hiroaki Iwamoto¹, Hiroto Imiya¹, Masato Ohashi², Sensuke Ogoshi¹

Affiliations

¹ Department of Applied Chemistry, Osaka University, Suita, Osaka 565-0871, Japan.
² Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.

PMID: 33112128
DOI: 10.1021/jacs.0c09639

Abstract

The first example of the oxidative addition of a C(sp³)-F bond in trifluoromethylarenes to a nickel(0) complex is described. A nickel(0) complex that bears two N-heterocyclic carbene (NHC) ligands of low steric demand is able to cleave C(sp³)-F bonds of trifluoromethylarenes to afford the corresponding trans-difluorobenzyl nickel(II) fluoride complexes. Isolation and characterization studies suggested that the cleavage of the C(sp³)-F bond proceeds via an η²-arene nickel(0) complex. Taking advantage of the reactivity of these nickel(II) fluoride complexes, we developed a catalytic hydrodefluorination of trifluoromethylarenes using hydrosilanes. A computational study indicated that the electron-rich nickel(0) center supported by two relatively small NHC ligands cleaves the C(sp³)-F bond via a syn-S_N2' mechanism.