The Applications Of A Zwitterionic Cu(â…¡)/Calix[4]Arene Complex In Water-phase Catalytic Oxidation And Oxidative Cyclization

The unique π system cavities and the multiple phenol oxygen atoms of calixarenes make these compounds capable of coordination with almost all metals. Owing to the good catalytic properties of these complexes, extensive efforts have been focused on the application of them in catalyzing organic reactions. In this thesis, we studied the applications of one zwitterionic Cu(II)/calix[4]arene complex in water phase oxidation and oxidative cyclization. The works include the following parts:1. A water-soluble cationic mononuclear copper(II) complex [Cu(II)L(H2O)]I2(1, H4 L = 5,11,17,23-tetrakis(trimethylammonium)-25,26,27,28-tetrahydroxycalix[4]arene) was employed as a catalyst in the oxidation of benzyl alcohols to benzaldehydes in water. The influence of the base, the oxidant, the temperature, the time interval and the molar ratio of catalyst on the course of the reaction were explored. Complex 1 exhibited good catalytic activity towards primary benzyl alcohols. The isolated yields of the aldehydes achieved 63-98% under relatively mild condition. 1H NMR, 13 C NMR of the aldehydes and the catalytic mechanism for the above reactions were also studied.2. Compound 1 was also employed as a catalyst in the oxidation of deoxybenzoin. It is further explored in catalyzing the preparation of quinoxalines via the oxidative cyclization. In water, 1 displayed effective reactivity for the oxidation of deoxybenzoin, and the oxidative cyclization of deoxybenzoin with 1,2-diamines. The yields of electron-donating substrates are higher than the withdrawing substrates.