One-Pot Palladium Reactions 

A New Reactivity Pattern for Vinyl Bromides; Cine-Substitution via Palladium Catalysed C-N Coupling/Michael Addition Reactions

Michael C. Willis, Jay Chauhan and William G. Whittingham  

Michael Willis and co-workers at the University of Bath have developed an efficient new one-pot carbon-carbon bond forming reaction, catalysed by palladium. 

The reaction proceeds via the palladium-catalysed conversion of a vinyl halide to an enamine, which then undergoes a Michael-type addition with an electron-poor alkene. The key benefit of the new one-pot procedure is that the unstable enamine does not have to be isolated, avoiding this potentially significant loss of material.

Adding significantly to the utility of the reaction, the new carbon-carbon bond is installed adjacent to the original carbon-halide bond. This complements the raft of traditional palladium-catalysed C-C bond forming reactions that introduce the new bond in the same position as the carbon-halide bond.

"In the future these types of processes will develop to deliver enantiomerically enriched products using chiral catalysts" commented Willis. The reaction is tolerant to a wide range of functional groups, suggesting that this conversion could find use in combinatorial and diversity-oriented synthesis.