Release of Isonitrile- and NHC-Stabilized Borylenes from Group VI Terminal Borylene Complexes

Marco Nutz; Bitupon Borthakur; Conor Pranckevicius; Rian D Dewhurst; Marius Schäfer; Theresa Dellermann; Fabian Glaab; Melanie Thaler; Ashwini K Phukan; Holger Braunschweig

doi:10.1002/chem.201800593

Release of Isonitrile- and NHC-Stabilized Borylenes from Group VI Terminal Borylene Complexes

Chemistry. 2018 May 7;24(26):6843-6847. doi: 10.1002/chem.201800593. Epub 2018 Apr 23.

Authors

Marco Nutz^{1

2}, Bitupon Borthakur³, Conor Pranckevicius^{1

2}, Rian D Dewhurst^{1

2}, Marius Schäfer^{1

2}, Theresa Dellermann^{1

2}, Fabian Glaab^{1

2}, Melanie Thaler^{1

2}, Ashwini K Phukan³, Holger Braunschweig^{1

2}

Affiliations

¹ Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
² Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
³ Department of Chemical Sciences, Tezpur University, Napaam, 784028, Assam, India.

PMID: 29498441
DOI: 10.1002/chem.201800593

Abstract

A family of doubly isonitrile-stabilized terphenyl borylenes could be obtained by addition of three equivalents of isonitrile to the corresponding Cr and W terminal terphenyl-borylene complexes. The mechanism of isonitrile- and carbon-monoxide-induced borylene liberation was investigated computationally and found to be significantly exergonic in both cases. Furthermore, addition of a small N-heterocyclic carbene (NHC) to a terminal Cr borylene complex results in release of an NHC-stabilized borylene carbonyl species, whereas the analogous reaction with bulkier phosphines results in metal-centered substitution.

Keywords: Lewis bases; boron; borylenes; imine ligands; transition-metal complexes.