Xia Chengfeng, a team of researchers from Yunnan University, published research results on Asymmetric Total Synthesis of indole alkaloids induced by visible light

Recently, Xia Chengfeng, a research team of Yunnan University, took the cyclization reaction induced by visible light as a key step to complete the asymmetric total synthesis of indole alkaloid (+ - flavisiamine f) of pistil for the first time The research results were published in angel Chem Int ed (DOI: 10.1002 / anie 201901241) under the title of "enioselective total synthesis of (+ - flavisiamine f via late stage visible light induced photochemical cycling" Dr Tong Xiaogang, a young teacher, is the first author of the paper Shi bingfei, Liu Qian, a graduate student, and Liang kangjiang, a postdoctoral student, are the co authors Xia Chengfeng, a researcher, is the corresponding author of the paper The complex indole alkaloids are the characteristic chemical constituents of Oleaceae, and these alkaloids have important physiological activities, which are the focus of natural product chemists and pharmacologists In this paper, we report a complex and rigid (+ - flavisiamine F-ring system, which consists of five continuous fused rings and one bridge ring At the same time, the molecule contains five continuous chiral centers, among which two all carbon quaternary carbon centers at C20 and C7 positions make the asymmetric total synthesis of target molecules very challenging Xia Chengfeng's team of researchers at Yunnan University constructed two challenging all carbon quaternary carbon chiral centers at C20 and C7 positions respectively through two consecutive 3,3-sigma-tropic rearrangement reactions and visible light-mediated free radical cyclization reactions, and for the first time realized the asymmetric total synthesis of indole alkaloid natural product (+ - flavisiamine f) In the synthesis strategy, the double bond in the molecule is cleverly designed to participate in two consecutive rearrangements and one cyclization reaction, which improves the synthesis efficiency and atomic economy At the same time, the author took the lead in using the visible light initiated cyclization reaction to construct the all carbon quaternary carbon chiral center C7 with high steric hindrance and fused ring structure, which provided a new strategy for the total synthesis of other all carbon quaternary carbon indole alkaloids with C7 position The above research was supported by NSFC, Yunnan applied basic research program, Western light of Chinese Academy of Sciences and innovation team development program of Ministry of education.