Photocatalytic Energy Transfer Mediated Bifunctional Reaction Of Olefines

Photochemistry used visible light as a green energy source features simple operations and mild conditions,thus attracting much attention from many scientists recently.Visible-light induced bifunctionalization of olefines could transform cheap and readily available industrial raw materials into high-valued compounds.The development of new bifunctional reagents which are suitable for photocatalyzed bifunctionalization of olefines is highly desirable.In this paper,three new bifunctional reagents based on benzophenone imide were designed and synthesized.Under photo conditions,bifunctionalization of various alkenes has been established through energy transfer process.The research work of this thesis is mainly divided into the following three parts:1)Novel dibenzoone oxime esters were designed and synthesized as diamination reagents.Diamination of alkenes were accomplished with thioxane as cheap and accessible photosensitizer under illumination of405 nm LEDs.This reaction was featured with mild condition and broad scope.More importantly,by fully taking advantage of reactivity difference between two kinds of nitrogen centered radicals,regioselectivity of this reaction was excellent.There is no doubt that this work will give a new dimension to better understanding of N-centered radicals.2)1,2-Sulfonylamination of alkenes were accomplished with sulfonylimides as new bifunctional reagents.A series ofβ-amino sulfonates were obtained in good to excellent yields with thioxane as photosensiter under illumination of 405 nm LEDs.In addition,race-Apremilast was synthesized in three steps by employing this method,which further demonstrated the practicability of the reaction.Under the auxiliary of computational chemistry,a possible reaction mechanism.was proposed.3)A bench-stable and readily accessible carboamination reagent N-（diphenylmethylene）-1,1,1-trifluoromethanesulfonamidewas synthesized.Enabled by an energy transfer（En T）process,an array of alkenes were able to be facilely CF₃-iminated under metal-free photocatalytic conditions.Crucial to the success of this strategy is the rational incorporation of diphenylmethanimine as the En T acceptor core in terms of compatible triplet energy.The mild reaction conditions and good functional group compatibility render this protocol highly valuable for the difunctionalization of olefines with structural complexity and diversity.These metal-free difucntianalization of alkenes have good substrate tolerance and mild conditions,witch hold promising applications in pharmacological studies.