Carbon annulation of ortho-vinylanilines with dimethyl sulfoxide to access 4-aryl quinolines.

A palladium-catalyzed annulation of ortho-vinylanilines with dimethyl sulfoxide was developed to access 4-aryl quinolines in moderate to good yields. Activated by 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct (DABSO), DMSO served as a "[double bond, length as m-dash]CH-" fragment in this transformation. It represents a facile pathway leading to 4-aryl quinolines.