铜催化氧化环化吡啶/异喹啉与查尔酮构建咪唑啉酮

IIn traditional transition-metal catalyzed oxidative coupling reaction, the expensive, scarce and toxic metal catalysts such as palladium, rhodium, iridium and gold are most used. Considering the sustainability and environmental standards, it is important in practical application to use the rich, cheap and non-toxic copper as a transition metal catalyst in catalytic synthesis. Here, we report a novel and efficient copper catalyzed direct tandem [3+2] cycloaddition/oxidation reaction from pyridines/isoquinoline, chalcones, ethyl chloroacetate and molecular oxygen under mild conditions to construct indolizines with molecular oxygen. And molecular oxygen is an ideal and green oxidant for catalytic chemistry. The direct utilization of molecular oxygen for the construction of valuable nitrogen-containing organic compounds is of great value in both academic and industrial communities due to its economic and environmentally benign features..