Radical Reactions Of 3-halooxindoles Via Visible-light Photocatalysis

Halide compounds are abundant in nature,easy to access and low-cost.Because of the high reactivity of C-X bond,they have been always the most important precusors for transformations of functional groups.In the past decades,visible light photocatalysis regained much attention from organic chemists due to their unique characters in catalyzing organic reactions.3-halooxindole plays a key role in the total synthesis of many important natural products,but radical reactions of them induced by visible light are rarely reported.So,we used 3-halooxindole as radical precursors and systematically studied their radical reactions.As following:1.The radical-addition reactions of 3-halooxindoles with unsatured organic compounds under visible light were explored.The results indicated that 3-oxindole radicals were too stable to add to unsaturated bonds.2.The dehalogenerated dimerization of 3-halooxindoles catalyzed by visible light were achieved,giving many key intermediates for the total synthesis of 3,3-dipyrroloindole-structured natural products.3.The radical-radical cross-coupling reactions of 3-halooxindoles with other radical precursors were researched,laying foundation for the manipulation of complex indole-based structure driven by visible light.