Our group are interested in developing new catalysts for cleaner organic transformations. This includes new types of catalytic reactions, and developing catalytic chemistry that does not work effectively at present. Solving these difficult problems often involves using skills in several chemical disciplines including organic synthesis, organometallic, mechanistic, supramolecular, co-ordination, and main group chemistry. As a general philosophy, the group likes to work on 'difficult reactions', and therefore designs catalysts from the bottom up, gaining a greater understanding of factors affecting catalytic activity and reaction mechanisms, prior to designing new catalysts for new / modified /difficult catalytic reactions.

Homogeneous Catalysis

We carry out a lot of work on carbonylation chemistry, ranging from trying to understand mechanistic issues, through to applying new catalysts in new applications that should prove useful organic syntheses. We are very interested in cross-coupling of poor nucleophiles, an overlooked aspect of this busy research field. We have also introduced various new asymmetric catalysts that are described further below.

Asymmetric Catalysis

A lot of our work is in asymmetric synthesis. Asymmetric synthesis has developed into one of the most important fields of modern chemistry. The most efficient method to prepare an enantiomerically pure compound is to use a tiny amount of a chiral catalyst to mediate an asymmetric transformation. We are interested in developing new families of chiral catalysts (both metal based, and purely organic catalysts) for a range of metal catalysed asymmetric reactions, including asymmetric hydrogenation, hydroformylation, hydroxycarbonylation, cross-coupling, Ene, and Michael additions. For example, we introduced Ru complexes of tridentate phosphine-diamine ligands as new family of catalysts able to hydrogenate poorly reactive ketones to enantiomerically enriched alcohols. We have also developed new applications for asymmetric hydroformylation in Organic synthesis, and developed new catalysts. A more fundamental interest has been the rational design of co-catalysts that can interact and enhance various catalysts using non-covalent bonding. The scheme below show this general approach (right), along with one of our chiral tridentate hydrogenation catalysts discussed above (left).

The group is supported by EPSRC, Leverhulme Trust, and several industrial companies, and tries to solve synthetic problems of industrial significance.

SELECTED RECENT PUBLICATIONS

1. Highly regioselective rhodium catalysed hydroformylation of unsaturated esters: the first practical method for quaternary selective carbonylation. M. L. Clarke and G. J. Roff, Chemistry: A Euro Journal, 2006, 12, 7978.
2. Palladium complexes of new bulky bidentate phosphines are active and highly regioselective catalysts for the hydroxycarbonylation of styrene, J. J. R. Frew, K. Damian, H. V. Rensburg, A. M. Z. Slawin, R. P. Tooze and M. L. Clarke Chemistry: A Euro. Journal 2009, 15, 10504.
3. Palladium-catalysed C-O bond formation using alkoxysilanes as nucleophiles, E. J. Milton, J. A. Fuentes and M. L. Clarke, Org. Bio. Chem. 2009, 7, 2645.
4. Enantioselective hydrogenation and transfer hydrogenation of bulky ketones catalysed by ruthenium complex of a chiral tridentate ligand, M. B. Diaz-Venezuela, S. D. Phillips, M. B. France, M. E. Gunn and M. L. Clarke, Chemistry; A Euro. Journal 2009, 15, 1227.
5. Self- Assembly of organocatalysts: a new approach to fine-tuning organocatalytic reactions. M. L. Clarke and J. A. Fuentes, Angew. Chem. Int. Ed. 2007, 46, 930