Facile Activation of Triarylboranes by Rhenium(V) Oxo Imido Complexes

Trevor D Lohrey; Emmanuel A Cortes; Robert G Bergman; John Arnold

doi:10.1021/acs.inorgchem.0c00658

Facile Activation of Triarylboranes by Rhenium(V) Oxo Imido Complexes

Inorg Chem. 2020 May 18;59(10):7216-7226. doi: 10.1021/acs.inorgchem.0c00658. Epub 2020 Apr 27.

Authors

Trevor D Lohrey^{1

2}, Emmanuel A Cortes¹, Robert G Bergman¹, John Arnold^{1

2}

Affiliations

¹ Department of Chemistry, University of California, Berkeley, California 94720, United States.
² Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.

PMID: 32339452
DOI: 10.1021/acs.inorgchem.0c00658

Abstract

We report the synthesis and reactivity studies of a pair of rhenium(V) oxo imido complexes. Oxidation of the rhenium(III) terminal oxo ORe(η²-DHF)(BDI) (DHF = dihydrofulvalene, BDI = N,N'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate) with organic azides R-N₃ (R = ^tBu, 2,6-diisopropylphenyl) yields the title complexes. Computational studies confirm that the rhenium oxo moieties of these complexes are polarized and correspondingly nucleophilic, owing to the preferential π bonding of the imido ligand to the Re center. This asymmetry in the metal-ligand multiple bond electronic structure facilitates the ready activation of B-C bonds in triarylboranes (BPh₃ and B(C₆F₅)₃), yielding rhenium(V) aryl borinate complexes. In the case of BPh₃, subsequent cyclometalation of the 1,2-addition products was found to take place upon heating, ejecting benzene to form bidentate diphenylborinate complexes.