Bis(phenolate)-functionalized N-heterocyclic carbene complexes of oxo- and imido-vanadium(V)

Oxo- and imido-vanadium(V) metal complexes supported by bis(phenolate)-functionalized N-heterocyclic carbene (NHC) ligands were synthesized structurally identified. In the presence of [(Ph3P)2N]Cl ([PPN]Cl), saturated NHC oxo-vanadium showed activity in coupling CO2 cyclohexene oxide (CHO) into cis-cyclohexene carbonate (cis-CHC). More importantly, complex bearing less electron-donating benzannulated ligand was found to be more active CHO conversion poly(cyclohexene carbonate) (PCHC) addition cis-CHC, highlighting beneficial effect weak ability latter vs. within such vanadium catalysts. Evaluation imido-vanadium catalyst performance led same selectivity as analogous catalysts owing its reactivity with via a [2 + 2] cycloaddition reaction forming an species.