A simple and highly efficient strategy for the synthesis
of 3-substituted
isocoumarins through a copper(I)-catalyzed reaction of 1-(2-halophenyl)-1,3-diones
has been developed. The procedure is based on a cascade copper-catalyzed
intramolecular Ullmann-type C-arylation and rearrangement process.
This methodology is tolerant of a wide range of substrates and applicable
to library synthesis.