Wu Jie group of Fudan University: using the strategy of free radical relay to insert sulfur dioxide to construct sulfonyl compounds

For a long time, the large-scale use of fossil fuels has led to the increase of sulfur dioxide in the atmosphere, which can promote the formation of acid rain and cause continuous damage to human production and life Therefore, the conversion of sulfur dioxide into harmless or available raw materials is an urgent problem to be solved In the field of organic chemistry, the attempt to introduce sulfur dioxide into small organic molecules has been going on, and a series of achievements have been made Due to the difficult operability of gaseous sulfur dioxide in organic synthesis, researchers later developed a series of solid sulfur dioxide substitutes for organic reactions In recent years, some substitutes, such as dabso, pyrosulfite, carving white powder, have been developed and widely used in organic synthesis Recently, Professor Wu Jie's research group of Fudan University has used the strategy of free radical relay to insert sulfur dioxide to construct sulfonyl compounds Relevant research results were published in org Lett (DOI: 10.1021/acs.orglett.9b00100) Introduction to Professor Wu Jie, professor and doctoral supervisor Mainly engaged in organic synthesis, pharmaceutical chemistry and related research In 2007, he was selected into the Ministry of education's "new century talent support plan" and Shanghai's "Pujiang talent plan", in 2010, he was awarded "Thieme Chemistry Journals Award", in 2013, he was awarded "do Innovation Challenge Award", in 2014-2018, he was successively selected into Elsevier's "China's top cited scholars" list, and in 2016-2017, he was successively selected into the Royal chemical society（ RSC) "top 1% high cited Chinese authors" list At present, he is the editorial board member of ACS combinatorial science of American Chemical Society and the young editorial board member of China Chemical express Since his independent work, he has published more than 280 SCI papers (including 140 if > 5.0 papers), cited more than 10000 times, participated in the preparation of four monographs, wrote one monograph, and obtained 2 US invention patents and 10 Chinese invention patents Prof Wu Jie, the research group has 6 doctors and 1 master The research focus is on the construction of sulfonyl compounds using sulfur dioxide insertion strategy The previous work focused on the early discovery of dabso as a source of sulfur dioxide for organic reactions, and developed a highly applicable free radical reaction system; developed some reaction types initiated by electrophilic reagents such as aryldiazonium salt and halogenated hydrocarbon, electrophilic reagents such as potassium fluoborate, which can realize the construction of a variety of sulfonyl compounds The follow-up work will continue to work in this area to explore the simple and easy sources of sulfur dioxide (such as pyrosulfite, carved white powder, etc.) for the construction of sulfonyl compounds, and explore more applications Leading scientific research achievements: Wu Jie group of Fudan University, which uses the free radical relay strategy to insert sulfur dioxide to construct the Methanesulphonic compounds, recently reported a case of using sodium methanesulphonate as the initiator to construct 3-methanesulphonylbenzothiazole compounds under visible light conditions The 2-alkynylbenzenesulfide used in this reaction is the key factor to realize the free radical relay strategy In previous reports, the substrate is easy to carry out its own 5-endo cyclization reaction to get benzothiophene and leave a molecular methyl segment It is noted that the atomic economy of this kind of cyclization can be improved by using the methyl fragments which are left Therefore, the strategy of free radical relay is proposed to capture the methyl fragments for subsequent transformation Figure 1 Project concept: at the beginning of sulfur dioxide insertion (source: org Lett.) research by using free radical relay strategy, the author hopes that the raw material 2-alkynylbenzenesulfide can provide methyl free radical through self cyclization, and the combination of methyl free radical and sulfur dioxide can generate methanesulfonyl free radical, which is in combination with 2-alkynylbenzenesulfide- After the addition and cyclization of alkynylbenzenesulfide, the target product is generated again to form methyl radicals for subsequent similar cycles The idea did not succeed (Figure 1) Fig 2 Template reaction (source: org Lett.) then, the author adopted the strategy of introducing the formyl radical externally to realize the reaction (Fig 2), that is, using the oxidized photosensitizer sodium methylsulfite under the condition of visible light to generate the formyl radical Sodium methylsulfite was used as the initiator 30% was selected as the standard condition and 81% yield was used to realize the template reaction Fig 3 shows the possible reaction mechanism After being oxidized by photosensitizer, sodium methylsulfite can obtain the methylsulfonyl radical Its attack on the three bonds of substrate 1 promotes the cyclization of substrate 1 and leaves one molecule of methyl radical The free methyl radical reacts with sodium pyrosulfite to get the methylsulfonyl radical again After a similar process, the product and the methyl radicals of the relay can be obtained Fig 3 Mechanism of free radical relay reaction (source: org Lett.) in summary, Wu Jie's group reported an example of using the strategy of free radical relay to construct 3-methylsulfonylbenzothiazole In this reaction, the catalytic amount of sodium methylsulfite was used as the initiator to realize the formation of methyl sulfonyl radical under the condition of light, which was added to the substrate and cyclized to obtain methyl radical, which reacted with pyrosulfite to generate methyl sulfonyl radical, and further reacted In this reaction, pyrosulfite and sodium methanesulphonate, which are easy to obtain, are used as reaction reagents to realize the efficient utilization of 2-alkynylbenzenesulfide, which embodies the atomic economy This article was published in org Lett (DOI: 10.1021/acs.orglett.9b00100) The author of this paper is Xinxing Gong, Mengjing Wang, Shengqing ye, and Jie Wu Review of previous reports: Professor Wu Jie's research group of Fudan University: sulfonation of C-H bond of aniline by sulfur dioxide insertion under the condition of no metal People and scientific research are increasingly valued in the economic life of scientific and technological elements Today, China has ushered in the "node of scientific and technological explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeangoapp, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the column of "people and scientific research", approach the domestic representative research group, pay attention to their research, listen to their stories, record their demeanor, and explore their scientific research spirit.