Transition metal catalyst complexes play important roles in organic synthesis. These complexes contain a central transition metal such as palladium as well as ligands that associate with the metal. The catalysts are used in a wide variety of carbon-carbon and carbon-heteroatom bond forming reactions.
The properties of the catalysts are recognized as being influenced by the nature of the central metal and also by the structure of the ligands. The structure of the ligands is believed to have an effect on rate constants and regioselectivity of the reactions, for example. Phosphine ligands including trivalent phosphorus are known for use with transition metals such as palladium. However, current ligands still require significant catalyst loading and are not optimal in either reaction completion or reaction rate. There is therefore a need for new and more effective phosphine ligands.