Work

Oxidative C–C Bond Formation Reactivity of Organometallic Ni(II), Ni(III), and Ni(IV) Complexes

Year: 2016

Type: article

Abstract: The use of the tridentate ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3tacn) and the cyclic alkyl/aryl C-donor ligand -CH2CMe2-o-C6H4- (cycloneophyl) allows for the synthesis of isolable organometallic NiII, NiIII, and NiIV complexes. Surprisingly, the five-coordinate NiIII complex is stable both in solution and the solid state, and exhibits limited C-C bond formation reactivity. Oxidation by one electron of this NiIII species generates a six-coordinate NiIV complex, with an acetonitrile molecule bound to Ni. Interestingly, illumination of the NiIV complex with blue LEDs results in rapid formation of the cyclic C-C product at room temperature. This reactivity has important implications for the recently developed dual Ni/photoredox catalytic systems proposed to involve high-valent organometallic Ni intermediates. Additional reactivity studies show the corresponding NiII species undergoes oxidative addition with alkyl halides, as well as rapid oxidation by O2, to generate detectable NiIII and/or NiIV intermediates and followed by C-C bond formation.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.6b10303

Authors: Michael B. Watson, Nigam P. Rath, Liviu M. Mirica

Institutions: Washington University in St. Louis, University of Missouri–St. Louis

Language: English

Topic: Organometallic Complex Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Division of Chemistry