Visible Light Induced Organic Dyes Catalyzed Synthesis Of α-Aryl Ketones And Derivatives

a-aryl ketone,as an important compound,is widely used in organic synthesis,medicinal chemistry,agricultural science and other fields.In those kinds of compounds,especially some nitrogen-containing amino ketones exhibit some special effect such as antibacterial,pain-inhibiting,neuro-inhibition and other pharmacological effects.Eosin Y without transition metal atoms is cheap and easy to obtain,which occupies an important position in photocatalysis.In this paper,Na2-eosin Y catalyzed alkylation of enol acetates by radical decarboxylation of N-hydroxyphthalimide esters was studied.Using the disodium salt of the eosin Y as a photosensitizer,the reaction could proceed well with enol acetates as an aryl source and N-hydroxyphthalimide esters(NHP)as the alkyl source,in N,N-dimethylformamide(DMF),at room temperature under green light irradiation.With its wide substrate applicability,excellent functional group tolerance and convenient operation,the catalytic system could afford desired a-aryl ketone products with high yields.Moreover,no additional base or oxidant is required in the reaction.The main research contents are as follows:Using 1,3-dioxoisoindolin-2-yl cyclohexanecarboxylate and 1-(4methoxyphenyl)vinyl acetate as template reaction substrates,we investigated the various parameters that influence the reaction and obtained the optimal reaction conditions.Then,under the optimal conditions,a wide range of substituted Nhydroxyphthalimide esters(NHP)and enol acetates were explored well affording the corresponding products up to 87%yield(Scheme 1).Base on a results from series of control experiments and free radical captire experiments,it is speculated that the reaction may involve free radical mechanism and provided the possible reaction mechanism.Scheme 1...