Coupling of carboxylic acids with internal alkynes by supported ruthenium catalysts: direct and selective syntheses of multi-substituted phthalide derivatives.

Abstract

Supported ruthenium catalysts promote coupling of various kinds of aromatic carboxylic acids with internal alkynes, giving the corresponding multi-substituted phthalide derivatives in high yields. The supported Ru catalyst can be recycled at least five times with no loss of activity.