DFT Studies of Alkene Insertions into Cu−B Bonds in Copper(I) Boryl Complexes.

DFT calculations have been carried out to study the insertion reactions of alkenes into the Cu−B bond in (NHC)Cu(boryl) complexes (NHC N-heterocyclic carbene). The nature of the insertion reactions and the relevant regiochemistry have been examined along with -hydride eliminations, which are followed by reinsertion of the alkene into the Cu−H bond. Hyperconjugation (i.e., bonding) between the Cu−C bond and the “empty” pzorbital on boron has been identified as the cause of the unexpectedly small Cu−C−B angle found experimentally by X-ray diffraction in -borylalkyl Cu(I) complexes. [ABSTRACT FROM AUTHOR]