p-TSA.H2O-Catalyzed Synthesis of 2,3-Diarylquinoline Derivatives via One-Pot Three-Component Reaction

An environmentally benign synthesis of 2,3-diarylquinolines is reported via a one-pot three-component reaction from arylamines, benzaldehyde, and styrene oxide in the presence of 20 mol% p-TSA center dot H2O at 120 degrees C. This protocol does not require metal catalysts, additives, and extra oxidants. Mechanistic studies confirm the crucial role of p-TSA center dot H2O and the use of air as the sole oxidant makes this transformation very attractive. The salient feature of this protocol is easy handling, broad substrates scope, shorter reaction time, high atom economy, regioselectivity, and good yields; and the formation of one C-N and two C-C bonds takes place in a single step.