Cobalt-catalyzed annulation of styrenes with α-bromoacetic acids

We report a method for addition of alpha-bromophenylacetic acids to vinyl C = C bonds in styrenes to afford gamma-lactones. Reactions employed a simple cobalt catalyst Co(NO3)(2)center dot 6H(2)O in the presence of dipivaloylmethane (dpm) ligand. Many functionalities including halogen, ester, and nitro groups were compatible with reaction conditions. If alpha-bromoesters were used, vinylacetates were the major products.

Automated summary

This method involves the addition of alpha-bromophenylacetic acids to vinyl C = C bonds in styrenes to produce gamma-lactones, using a cobalt catalyst and dipivaloylmethane (dpm) ligand. The reaction conditions are compatible with various functionalities including halogen, ester, and nitro groups. When using alpha-bromoesters, the major products obtained are vinylacetates.