Oxidative addition of an alkyl halide to form a stable Cu(III) product.
- Resource Type
- Article
- Authors
- Yongrui Luo; Yuli Li; Jian Wu; Xiao-Song Xue, ; Hartwig, John F., ; Qilong Shen,
- Source
- Science; 9/8/2023, Vol. 381 Issue 6662, p1072-1079, 8p, 4 Graphs
- Subject
- Oxidative coupling
Haloalkanes
Copper
Oxidative addition
Electrophiles
Azoles
Oxidation-reduction reaction
- Language
- ISSN
- 00368075
The step that cleaves the carbon-halogen bond in copper-catalyzed cross-coupling reactions remains ill defined because of the multiple redox manifolds available to copper and the instability of the high-valent copper product formed. We report the oxidative addition of a-haloacetonitrile to ionic and neutral copper(I) complexes to form previously elusive but here fully characterized copper(III) complexes. The stability of these complexes stems from the strong Cu−CF3 bond and the high barrier for C(CF3)−C(CH2CN) bond-forming reductive elimination. The mechanistic studies we performed suggest that oxidative addition to ionic and neutral copper(I) complexes proceeds by means of two different pathways: an SN2-type substitution to the ionic complex and a halogen-atom transfer to the neutral complex. We observed a pronounced ligand acceleration of the oxidative addition, which correlates with that observed in the copper-catalyzed couplings of azoles, amines, or alkynes with alkyl electrophiles. [ABSTRACT FROM AUTHOR]