Reactions of an anionic chelate phosphane/borata-alkene ligand with [Rh(nbd)Cl](2), [Rh(CO)(2)Cl](2) and [Ir(cod)Cl](2)

Borata-alkenes can serve as anionic olefin equivalent ligands in transition metal chemistry. A chelate ligand of this type is described and used for metal coordination. Deprotonation of the Mes(2)P(CH(2))(2)B(C(6)F(5))(2) frustrated Lewis pair in the α-CH[B] position gave the methylene-bridged phosphane/borata-alkene anion. It reacted with the [Rh(nbd)Cl] or [Rh(CO)(2)Cl] dimers to give the respective neutral chelate [P/C[double bond, length as m-dash]B][Rh] complexes. The reaction of the [P/C[double bond, length as m-dash]B](–) anion with [Ir(cod)Cl](2) proceeded similarly, only that the complex underwent a subsequent oxidative addition reaction at the mesityl substituent. Both the resulting Ir(iii)hydride complex 15 and the P/borata-alkene Rh system 12 were used as hydrogenation catalysts. The [P/C[double bond, length as m-dash]B(C(6)F(5))(2)]Rh(nbd) complex 12 served as a catalyst for arylacetylene polymerization.