Three-Component Reactions of Aldehydes, Amines, and Alkynes/Alkenes Catalyzed by Trifluoromethanesulfonic Acid: An Efficient Route to Substituted Quinolines

Abstract

Herein, we have developed a facile and economic HOTf-catalyzed synthesis for the construction of quinolines from aldehydes, amines, and alkynes/alkenes, which are readily available from commercial vendors. The electronic properties of the substituents on the aldehydes, amines, and alkynes/alkenes have been investigated. It was found that molecules with both electron-donating and electron-withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is important for the development of new atom-economic strategies and this strategy is efficient in building complex structures from simple starting materials in an environmentally benign fashion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.