Study On Carboamination And Carboxygenation Of Alkenes Based On Designing Reaction Strategy

Carboamination and carboxygenation reaction of alkenes have been employed as an economic and simple method that can simultaneously introduce two different types of functional groups into double bonds,thus leading to a wide range of applications in pharmaceutical,agrochemical,and material science fields.Meanwhile,the design,development and application of new reactions and new strategies always serve as a driving force for organic synthesis.Therefore,in this thesis,we established two distinct strategies to achieve carboamination and carboxygenation of alkenes.This thesis can be divided into two parts according to different strategies.Part 1.Design of a new strategy for transformation of alkenes based on manganese catalysis and its application in carboamination of alkenesThe exploration of new chemical reactions has led to the discovery of many widely used and reliable named reactions.The understanding and application of key intermediates provide a basis for the continuous development and improvement of these significant reactions.As these named reactions have undergone a long-term synthetic practice,it is a outstanding challenge to establish a distinct approach based on classic named reaction conditions.Through a rational analysis of the nature of these named reactions,we envisioned that controlling the different reactivities of intermediate would open up a new door to discover new reactions.The addition of suitable competitive reagents to the typical reaction conditions would enable trapping of the reactive intermediate in a distinct way in contrast to classical reaction pathway.Therefore,the precise control of chemoselectivity results in the generation of new species to participate in the reaction,thus overriding the classical pathway and establishing a new reationAs a practice of our idea,we established a new alkene transformation strategy based on Jacobsen-Katsuki epoxidation reaction,a classical reaction with a research history of more than thirty years.The reactive oxomanganese(?)species can readily a hydrogen atom from C-H bonds to generate a substrate-derived radical and a hydroxomanganese(?)intermediate,thus shutting down the highly competitive epoxidation pathway and establishing a manganese-catalyzed new strategy for transformation of alkenes.Part 2.Design of a new strategy for transformation of alkenes based on iodonium ylides and its application in carboamination and carboxygenation of alkenesIodonium ylides have been widely used to generate carbene or carbenoid species.These ylide compounds could be applied in transformations in which they act as nucleophiles or electrophiles.However,the application of iodonium ylides in single-electron-transfer processes remains largely elusive.To uncover exceptional property of iodonium ylides,we aimed at developing unprecedented transformations between Lewis bases and iodonium ylides through a single electron transfer process.We envisioned that the halogen-bonding complex between iodonium ylides and Lewis bases could induce a single-electron-transfer process to generate radical ion pair.The trapping of these radical ion pair by alkenes would achive new chemical transformation.As an application of this strategy,we established a new approach to achieve a three-component carboamination of alkenes with simple primary and secondary amines and iodonium ylides,directly leading to the generation of ?-amino acid derivatives.In this transformation,C-N bond formation was realized via trapping of transient aminium radical cations in the presence of a catalytic amount of succinimide as a proton shuttle.The application of amines to a carboamination process via trapping of aminium radical cations remains an unsolved problem.Transformation of simple amines based on iodonium ylides provides a promising solution to the controllable generation and application of aminium radical cations.In order to further develop this strategy,we established a new approach to carboxygenation of alkenes using alkenes,hydroxylamines(or oximes),and iodonium ylides as reactants.This reaction was generally finished within only a few minutes in the absence of any additive.This transformation has a broad substrate scope as aliphatic,aromatic,and heterocyclic olefins are tolerated.