Copper-Catalyzed Annulation or Homocoupling of Sulfoxonium Ylides: Synthesis of 2,3-Diaroylquinolines or α,α,β-Tricarbonyl Sulfoxonium Ylides.

An unprecedented copper-catalyzed reaction of sulfoxonium ylides and anthranils is reported that enables an easy access to 2,3-diaroylquinolines through a [4+1+1] annulation. Copper-catalyzed homocoupling of sulfoxonium ylides provided α,α,β-tricarbonyl sulfoxonium ylides, which provides a strategy to extend the carbon chain through C-C bond formation. The utility of the products as well as the mechanistic details of the process are presented.