ABSTRACT
Reactions involving C(sp3)-H bonds of azaarenes have been widely studied in recent years as they allow direct functionalization of these N-heterocycles without the use of harsh reaction conditions. In this work, we describe the C(sp3)-H functionalization of 4-methylquinazolines and 1-benzylisoquinolines, employing α-substituted ß-nitrostyrenes catalyzed by inexpensive copper acetate. Under the optimized condition, 21 pyrrolo[1,2-c]quinazolines, as well as an imidazo[1,2-c]quinazoline and 4 pyrrolo[2,1-a]isoquinolines, were obtained in moderate to good yields. Furthermore, the biological activity of the pyrrolo[1,2-c]quinazolines was evaluated against Plasmodium falciparum, and promising results were obtained.
Subject(s)
Antimalarials , Quinazolines , Copper/pharmacology , Copper/chemistry , Isoquinolines/chemistry , CatalysisABSTRACT
Ultrasound is an essential technique to improve organic synthesis from the point of view of green chemistry, as it can promote better yields and selectivities, in addition to shorter reaction times when compared to the conventional methods. Heterogeneous catalysis is another pillar of sustainable chemistry being the recycling and reuse of the catalysts one of its great advantage. In the other hand, multicomponent reactions provide the synthesis of structurally diverse compounds, in a one-pot fashion, without isolation and purification of intermediates. Thus, the combination of these protocols has proved to be a powerful tool to obtain biologically active organic compounds with lower costs, time and energy consumption. Herein, we provide a comprehensive overview of advances on methods of organic synthesis that have been reported over the past ten years with focus on ultrasound-assisted multicomponent reactions under heterogeneous catalysis. In particular, we present pharmacologically important N- and O-heterocyclic compounds, considering their synthetic methods using green solvents, and catalyst recycling.
