The Study Of Visible Light-induced Radical Aryl Migration Reaction

In recent years, along with the people’s deepening understanding of the visible light induced reaction process in free radical organic synthesis chemistry, the visible light-induced reactions have been widely applied in organic synthesis. Free radical migration reactions have been known as an effective method to construct the new chemical bond. But stoichiometric unenvirenmentally free radical initiator such as metal organic compounds and peroxide compounds were often used in the traditional aryl migration reactions. What’s more, the reactions were usually occurred under high temperature. These shortcomings clearly did not meet the requirements of green chemistry. In this paper, we have developed a visible light induced rearrangement to construct C-C bonds via intramolecular aryl migration and desulfonylation process to form a variety of multi-substituted N,2-diarylacetamide. This reaction condition was characterized by its operational simplicity and high yields under mild conditions. This paper mainly includes the following parts.1. According to different free radical reaction mechanism, we have simply introduced visible light induced catalytic reaction of current researches. This paper briefly introduced the applications of free aryl migration reaction in organic synthesis. According to the type of reaction, some research progresses of visible light induced catalysis were simply introduced. The applications of aryl transfer reaction in organic synthesis were briefly introduced.2. A series of ligands were synthesized such as 2-(4-t-Butylphenyl) pyridine, bipyrazinyl and so on. Some commonly used photocatalysts for instance Ru(bpz)3(PF6)2, [Ir(ppy)2bpy](PF6), [Ir(tb-ppy)2bpy](PF6), fac-Ir(ppy)3 were introduced in this paper.3. Based on the free radical reduction quenching mechanism, a kind of visible light-induced aryl migration reaction under very mild condition was developed. The amide compounds was formed with the action of visible light catalyst fac-Ir(ppy)3, while 2-bromine-2-methyl-N-phenyl-N-(benzenesulfonyl)propionamide could occur dehalogenation to form α-carbonyl radicals and then undergone a intramolecular 5-ipso addition. The desulfonylation progress could occurr to form a series of a variety of multi-substituted N,2-diarylacetamide. A visible light-induced aryl migration reaction has been introduced in this paper. In addition, solvent was used as the reduction quencher instead of the traditional photoredox reaction quencher such as Hansenester. The NMR, HR-MS, method have been used to characterize of various compounds. The byproducts were also analysised by HPLC-MS.