Synthesis of substituted naphthalenes by the palladium-catalyzed annulation of internal alkynes

[reaction: see text] A variety of substituted naphthalenes have been prepared by the palladium-catalyzed carboannulation of internal alkynes. This method (1) forms two new carbon-carbon bonds in a single step, (2) accommodates a variety of functional groups, and (3) affords excellent yields of highly substituted naphthalenes.