Study On The Catalytic Reaction Of Perylenequinonoid Pigments As Organic Photocatalyst Under Visible Light

Visible light is a green resource,and the visible light-induced reaction has been widely concerned due to its mild reaction conditions and simple operation.The organic dye photocatalyst has better solubility,lower cost and less environmental pollution than the transition metal catalyst.In this paper,two kinds of reactions were realized by using the fermentation product of cercosporin,a compound of quinone structure as a photocatalyst.This work laid the foundation for the reaction and subsequent research of cercosporin as an organic photocatalyst.The specific work is as follows:The first part of the work is based on C–H arylation under visible light using cercosporin as a catalyst,and a series of substrates are synthesized.By optimizing the reaction conditions of catalysts,reaction solvents,light sources,etc.,we have developed a method for the direct arylation of visible light-induced(het)aromatic hydrocarbons under mild conditions using a new class of organic photocatalysts.Substrate expansion experiments found that this C–H direct arylation method is compatible with a variety of functional groups,enabling efficient reaction with aromatic hydrocarbons,electron-deficient heteroaromatics,and electron-rich heteroaromatics,with excellent regioselectivity and broad substrate range.At the same time,through the experiments of mechanism exploration experiment and intermolecular competition,the possible reaction mechanism is given.This work provides a simple and efficient method for achieving direct C–H direct arylation of aromatic hydrocarbons.The second part of the work is selective oxidation reaction under visible light-mediated mild conditions,and a series of ketones,aldehydes and sulfoxide products are synthesized.By using cercosporin as a catalyst for the reaction,we selectively oxidize the benzylic C–H bond to the carbonyl group,selectively oxidize the amine to the aldehyde,and selectively oxidize the sulfide to the sulfoxide in high yield and high selectivity.Cercosporin is a multifunctional and environmentally friendly photocatalyst.And through a series of mechanism control experiments,three possible reaction mechanisms are presented.The method uses inexpensive light source under very mild conditions,and the cheap photocatalyst can realize selective oxidative conversion,which is sustainable and environmentally friendly,and provides reference for subsequent research.