Ligation of Boratabenzene and 9-Borataphenanthrene to Coinage Metals

Abstract

The reactions of boratabenzene and borataphenanthrene anions with group 11 Ph 3 PMCl reagents furnished η 2 coordination complexes, with the exception of the copper boratabenzene species that adopted an η 6 mode. The binding of arene ligands to copper in an η 6 manner is rare, and altering the ancillary ligand on copper to an N-heterocyclic carbene switched the binding of the boratabenzene to η 2 , indicating that such ligands are capable of vacating coordination sites. The η 2 coordination complexes bind side-on, akin to olefins, via a borataalkene unit, although with the carbon atom much more proximal to the metal center than boron.

Borataalkenes, boraalkenes, and the η2-B,C coordination mode in coordination chemistry and catalysis

“…Building upon this work, Martin subsequently reported the complete series of group 11 borataalkene complexes derived from boratabenzene and borataphenanthrene anions (Scheme 14). 28 Boratabenzene 58 was reacted with group 11 metal chlorides to give the corresponding η 2 -B,C borataalkene complexes 59–61 . In all cases the M–C bond distances were shorter than the M–B bond distances.…”

The BC bond: some recent developments

“…The examples 16 and 17 , in contrast, were prepared in a more convenient way, namely by the reaction of the respective borataalkene anion with the metal halides. 11,12…”

Borataalkenes and the η2-B,C Coordination Mode in Coordination Chemistry and Catalysis

“…Building upon this work, Martin subsequently reported the complete series of group 11 borataalkene complexes derived from boratabenzene and borataphenanthrene anions. 20 Boratabenzene 31 was reacted with group 11 metal chlorides to give the corresponding η 2 -B,C borataalkene complexes 32-34 (Scheme 7). In all cases the M-C bond distances were shorter than the M-B bond distances, reflecting the high electronegativity of late transition metals.…”