The aerobic oxidation of α-hydroxy ketones into α-diketones catalyzed by CaO is compared with the same reaction catalyzed by other metal oxides. The catalytic activities of the various metal oxides were proportional to their surface basicities. The direct conversion of α-hydroxy ketones into quinoxalines via CaO-catalyzed aerobic oxidation followed by in situ reaction with 1,2-diaminoaromatics is also achieved. Various types of quinoxalines were synthesized in the presence of the CaO catalyst and molecular oxygen. It was also found that the CaO catalyst was reusable without any loss of its catalytic activity.
通过比较CaO与其他金属氧化物催化α-羟基酮到α-二酮的好氧氧化反应,研究了CaO的催化活性。各种金属氧化物的催化活性与其表面碱性成正比。通过CaO催化的好氧氧化反应,直接将α-羟基酮转化为喹喉,并在原位与1,2-二
氨基芳香化合物反应,也实现了这一转化。在CaO催化剂和分子氧的存在下,合成了各种类型的
喹喔啉。还发现CaO催化剂可以重复使用,且没有任何催化活性的损失。