Research project: Whitby: Invention of new transition metal catalysed reactions
Developing new transition metal catalysed processes forms an important part of our work.
Project Overview
One example is the zirconium mediated 2-aluminoethylalumination reaction (Eq. 1)[1] and related transformations of organomagnesium reagents.[2]
Recently we have developed a palladium catalysed multi-component synthesis of aryl amidines and imidates (Eq. 2).[3][4] The method extends to intramolecular cases,[5] the use of alkenyl halides,[6] and can be optimized to form unusual alpha-iminoimidates (1).[7]
Currently our aim (in collaboration with Dr. Andreas Danopoulos) is to find a catalytic version (Eq. 3) of the zirconium mediated stoichiometric amine synthesis we reported over a decade ago.[8]
With Dr. Andreas Danopoulos we are also developing the use of N-heterocyclic carbene nickel complexes as catalysts.
[1] Zirconium-catalysed enantioselective 2-aluminoethylalumination of alkenes. Dawson, G.; Durrant, C. A.; Kirk, G. G.; Whitby, R. J.; Jones, R. V. H.; Standen, M. C. H. Tetrahedron Lett. 1997, 38, 2335-2338.
[2] Asymmetric ethylmagnesiation of alkenes using a novel zirconium catalyst. Bell, L.; Brookings, D. C.; Dawson, G. J.; Whitby, R. J.; Raymond, V. H.; Michael, C. H. Tetrahedron 1998, 54, 14617-14634.
[3] A palladium-catalyzed synthesis of amidines from aryl halides. Saluste, C. G.; Whitby, R. J.; Furber, M. Angew. Chem. Int. Ed. 2000, 39, 4156-4158.
[4] Palladium-catalysed synthesis of imidates, thioimidates and amidines from aryl halides. Saluste, C. G.; Whitby, R. J.; Furber, M. Tetrahedron Lett. 2001, 42, 6191-6194.
[5] Palladium catalysed synthesis of cyclic amidines and imidates. Saluste, C. G.; Crumpler, S.; Furber, M.; Whitby, R. J. Tetrahedron Lett. 2004, 45, 6995-6996.
[6] Palladium-catalysed three component synthesis of alpha,beta- unsaturated amidines and imidates. Kishore, K.; Tetala, R.; Whitby, R. J.; Light, M. E.; Hursthouse, M. B. Tetrahedron Lett. 2004, 45, 6991-6994.
[7] Synthesis of alpha-iminoimidates by palladium catalysed double isonitrile insertion. Whitby, R. J.; Saluste, C. G.; Furber, M. Org. Biomol. Chem. 2004, 2, 1974-1976.
[8] Structure-Reactivity Correlations for the Formation of Zirconocene Eta-2-Imine Complexes from Amines. Coles, N.; Harris, M. C. J.; Whitby, R. J.; Blagg, J. Organometallics 1994, 13, 190-199.