Dr Ben Ward - D.Phil. MRSC
Research in the Ward group is concerned with the catalytic applications of main group and early transition metal organometallic and coordination complexes. Our research specifically concentrates on the Alkaline Earth metals (magnesium, calcium and strontium) and the lanthanide metals.
- Preparation of new ligand environments for S-block and early transition metals
- Development of asymmetric catalytic reactions using alkaline earth and lanthanide metals
- Analysis of the coordination chemistry of alkaline earth and lanthanide metals when supported by chiral ligand environments
- Reaction mechanism determination using spectroscopic analysis of catalytic intermediates
One of our recent highlights has been the development of chiral calcium complexes for the asymmetric hydroamination of amino-olefins.[1,2] In our latest publications, we reported the highest enantioselectivity for this reaction when using calcium as an environmentally friendly and inexpensive alternative to precious metal catalysts.
One of the major challenges associated with the coordination complexes of calcium is their propensity to undergo ligands redistribution, or “Schlenk” equilibria. This is a significant problem in relation to their catalytic performance, and ligands need to be designed that are able to control or supress these processes.
In order to achieve our aims in catalysis, a significant amount of effort is spent on the development of new chiral ligands: we have recently reported a general route to a class of N-functionalised ethylene diamines, which can be employed either as ligands in their own right, or as precursors for preparing imidazoline ligands.
1. “Chiral calcium catalysts for asymmetric hydroamination/cyclisation”, J. S. Wixey and B. D. Ward, Chem. Commun., 2011, 47, 5449. DOI: 10.1039/c1cc11229e
2. “Modular ligand variation in calcium bisimidazoline complexes: effects on ligands redistribution and hydroamination catalysis”, J. S. Wixey and B. D. Ward, Dalton Trans., 2011, 40, 7693. DOI: 10.1039/c1dt10732a