Photocatalytic Decomposition Of Benzophenone Acyloxy Oxime Esters And Its Application In C_sp3-H Functionalization

Carbon-nitrogen bond is one of the most common carbon-heteroatom bonds.The formation of carbon-nitrogen bond is important in modern organic synthesis.The development of a more moderate reaction conditions,cheap and sustainable way of catalytic conforms to the development trend of green chemistry and atom economy.Through the use of photosensitizer absorb photons produce excited state of reactive implementation chow ring,atomic extraction reaction or different synthetic reactions such as isomerization process has been widely reported.Mediated by visible light energy transfer(En T)photocatalysis can be a more moderate reaction conditions to obtain excited reaction instead of direct light.Energy transfer photocatalytic compared with single electron transfer(SET)photocatalytic have higher atom utilization,more in line with the atom economy.Energy transfer photocatalytic need to select the matching triplet energy substrate and light catalyst.Activate the activity of free radicals by N-O bond intermediates is the key to realize the functional molecules,dual functional oxime ester compounds through energy transfer light catalyst for olefin selectivity of functionalization reaction has been widely reported.Saturated C-H bonds is difficult to achieve the C(sp~3)-H bonds substrate for the functionalization due to its low reactivity and poor regioselectivity,Hydrogen transfer mediated by light is currently the most important way to realize the C(sp~3)-H bonds functional.This article used the Thioxanthone as photocatalyst,through the energy transfer photocatalytic process under visible light irradiation carboxylic acid oxime ester realized N-O bond homolysis and decarboxylation.By producing the active carbon radical intermediates and the steady state nitrogen radical intermediates to realized oxime esters compounds decomposition decarboxylation and the functionalization of saturated C-H bonds compounds.The first part:this part of the preparation of three kinds of oxime ester compounds,namely Diphenylmethanone O-(2-phenylacetyl)oxime,Diphenylmethanone O-cyclohexanecarbonyl oxime,Diphenylmethanone O-benzoyl oxime,and through the nuclear magnetic spectrum,infrared spectroscopy and mass spectrum for material analysis.Then,using the Thioxanthone as photocatalyst to explore three oxime ester compounds reaction of decomposition decarboxylation.Results show that the Diphenylmethanone O-(2-phenylacetyl)oxime and Diphenylmethanone O-cyclohexanecarbonyl oxime can implement decomposition decarboxylation,generate the corresponding decarboxylation products.After the optimized reaction conditions,the productive rate of N-benzyl-1,1-diphenylmethanimin and N-cyclohexyl-1,1-diphenylmethanimine is respectively:53.8%and 60.8%.The second part:With the Thioxanthone as photocatalyst,Diphenylmethanone O-benzoyl oxime reaction with toluene and acetonitrile.Results show that the Diphenylmethanone O-benzoyl oxime can react with toluene and acetonitrile to generate the corresponding functionalized products.After the optimized reaction conditions,the productive rate of N-benzyl-1,1-diphenylmethanimin and 2-((diphenylmethylene)amino)acetonitrile is respectively:48.3%and 61.4%.