Phosphabenzenes as electron withdrawing phosphine ligands in catalysis
Abstract
The utility of phosphabenzenes as ligands in late transition metal catalysis is examined. Molecular orbital calculations indicate that phosphabenzenes possess a low lying LUMO permitting π-back bonding interactions. The resultant electron withdrawing nature of the phosphabenzenes is beneficial for reactions in which reductive elimination steps are rate-limiting. For example, phosphabenzenes were found to function well in nickel catalyzed [4 + 2] cycloadditions.