Nickel Catalyst Radical Reaction Of Iododifluoromethyl Ketones With Alkenes

Fluorine,as ever,imparts difluoroketones with unique properties,both in terms of their reactivity and in their physical properties,as the introduction of fluorine can effectively change a series of biologically relevant properties such as metabolic stability,alkalinity,bioavailability,and lipophilicity of the compounds.Recently,a number of efficient catalytic methods for installation of ?,?-difluoroketones into organic compounds have been developed and most of these reactions involve radical processes,in which transition metal catalysis and photoinduced catalysis are recognized as the most effective systems for generating difluoroalkyl radical intermediates under mild reaction conditions.In this paper,we described a Ni-catalysed radical difunctionalization of alkenes for installation of?,?-Difluoroketones into organic molecules.?,?,?-Iododifluoromethylketone reagents were utilized as the radical precursors.Whilst,a diverse of heterocyles have been accessed via this protocol,such as hydrofurans,benzohydrofurans,indolinones,etc.The first part introduces the atom transfer radical addition reaction between?,?,?-Iododifluoromethylketone reagents and unactivated olefins under Ni-catalysis.The types of the catalyst,ligand,base,solvent and reaction temperature involved in the system were screened to obtain optimized reaction conditions.Specifically,under the protection of nitrogen,when Ni(acac)2(5mol%)was used as a catalyst,1,10-phenanthroline(6 mol%)was as a ligand,K2CO3 and cyclopentyl methyl ether were used as a base and a solvent respectively,the difluoroketones reacted with the unactivated olefin in an oil bath at 100? for 5-8 h to obtain 20 different types of difluoroalkylated products.In the second part the application of the above nickel catalyst system in organic synthesis were described.The regulation of alkali reagents realizes the radical cyclization reactions of ?,?,?-Iododifluoromethylketone reagents with enol,enoic acid,enamine or allylphenol.Six difluoromethylated heterocyclic compounds such as hydrogen furan,benzofuran and anthrone were obtained respectively.