Titanium-based nanoparticles: A novel, facile and efficient catalytic system for one-pot synthesis of quinoline derivatives

Abstract

Abstract Recently, the synthesis and application of metal nano particles have received considerable attention in view of their unique properties compared to the bulk metals. Metal nano particles have a characteristic high surface area that translates into more active sites per unit area, and can maximize the reaction rates and minimize consumption of the catalyst. In the present work, we have explored a novel, convenient, highly versatile and eco-friendly protocol for the synthesis of quinolines. This protocol is based on the use of TiO2 Al2O3 ZrO2 as an efficient and reusable nano-structured catalyst. A variety of anilines reacts with ethyl acetoacetate afforded the substituted quinolines in excellent yields. The advantages of method are short reaction times with milder conditions, easy work-up and purification of products by non-chromatographic methods. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency. The methodology presented offers significant improvements for the synthesis of quinolines with regard to yield of products, simplicity in operation and green aspects by avoiding toxic conventional catalysts.