Organic Preparations and Procedures International | 2019
One-Pot Synthesis of Polyhydroquinolines Catalyzed by ZnCl2 Supported on Nano Fe3O4@SiO2
Abstract
The development of an atom-economical approach for the efficient construction of diversely functionalized molecules from easily accessible starting materials is always a special issue for synthetic organic chemists. The 4-substituted 1,4-dihydropyridine (1,4-DHP) nucleus is a rich source of biological molecules which are useful as antihypertensive, vasodilator, antitherosclerotic, antitumor, geroprotective and antidiabetic agents. These compounds also have activities as neuroprotectants and as platelet anti-aggregants. They have cerebral antischaemic activity in the treatment of Alzheimer’s disease and chemosensitizer behavior in tumor therapy. The valuable cardiovascular agents nifepidin, felodipine and amlodipine belong to this category of compounds, and they play important roles in hypertension treatments. They have shown usefulness in the treatment of angina pectoris and other cardiovascular diseases. The best methods for the synthesis of polyhydroquinolines are multicomponent reactions. These advantageous reactions are in agreement with green chemistry principles such as atom economy and resource-effectiveness bond-forming efficiency. There are many approaches in the literature for the preparation of polyhydroquinolines. They include the use of such catalysts as Co3O4-CNTs, 18 Ni0.35Cu0.25Zn0.4Fe2O4 MNPs, ceric ammonium nitrate, cetyltrimethylammonium bromide, MCM-41, p-TSA, scolecite, hafnium(IV)bis(perfluorooctanesulfonyl)imide, PPA-SiO2, 26