Dynamic Covalent Reactions Of The Heminaminal Ether And Dibenzaldehyde

Depending on the environment,dynamic covalent bonds are dual in nature,they can be as unstable as non-covalent bonds,and they can be as strong as covalent bonds.They combine the ability of supramolecular chemistry to be regulated and the’stability of covalent bonds.Under the influence of external reagents,through the reversible chemical reaction of component exchange or recombination,can respond to physical stimuli or chemical effectors and behave as an adaptive material.Dynamic covalent chemistry plays an important role in the fields of molecular switch regulation,functional material assembly,and biomolecular regulation.Therefore,the exploration of the dynamic assembly system is of great significance not only in the field of chemistry but also in the intersection of various disciplines.First,the dynamic assembly system based on cyclic hemiacetal ethers was synthesized.Its dynamics,assembly process,and product analysis were further explored.Secondly,biphenyl aromatic aldehydes with different substituents were synthesized and studied in this work.The dynamic imine formed by reacted these compounds with different amines was realized.The effect of aromatic ring substituents to achieve the regulation of the reaction equilibrium and stability.The research content mainly includes two aspects:(1)This chapter designs and synthesizes dynamically reversibly exchangeable cyclic hemiacetal ether derivatives.Using this as a model,it explores the dynamic covalent reversibility and competition with different amines through classical methods such as aldehyde exchange and amine exchange reaction.The product and its distribution were determined by crystal structure and IH-NMR spectrum analysis.The products were mainly cyclic hemiacetaminoethers.By exploring the reaction mechanisms of such hemiacetal ethers,determine the feasibility and practicality of such reactions.(2)By synthesizing biphenyl aromatic aldehyde series compounds with different substituents and reacting with different amines in the organic phase,the reactivity of the aldehyde compounds and the stability of the imine products were explored.First,by the amine exchange reaction,the equilibrium constants of the amine exchange and the aldehyde exchange between the components were calculated and the stability of the coupling product was explored.Secondly,this dissertation systematically studies the substituents on the aromatic rings and discusses the effect of substituents on the dynamic assembly system.Finally,the best reactive compounds screened out were introduced into water-soluble groups for amino acid modification and their reactivity and product stability were explored in the aqueous phase,which is an application of the molecules in the regulation of biological functions.