Synthesis Of Amine Compounds Based On Hydrogen Transfer/Dehydrogenation Strategy

As an important class of nitrogen-containing compounds,amines have many applications in industry,agriculture and biomedicine.Conventional methods for synthesizing amines are generally based on either pre-preparation of substrates or the use of halogen-containing reagents,thereby contaminating the environment.In consideration of sustainable development,how to achieve the synthesis of amine compounds with efficient and green synthetic strategies has always been a hot topic of basic research.At present,hydrogen transfer and dehydrogenation strategies are two economical,efficient,and green approaches to achieve the construction of fatty and aromatic amines.Therefore,the research contents of this dissertation mainly focus on the synthesis of a variety of amines by using hydrogen transfer or dehydrogenation strategy through a simple and effective catalytic system.First,the thesis describes the synthesis of anthranilamides and anthranilates,a class of compounds widely used in the field of organic synthesis and found in numerous natural medicines,via the transfer hydrogenative coupling of a variety of different o-nitrobenzyl alcohols with readily available alcohols or amines in a highly efficient and green one-step way by using cesium carbonate as a catalyst.The advantage of this method is that it avoids the use of transition metal catalyst in the reaction,and has the characteristics of simple operation,wide substrate adaptability and good functional groups tolerance.It provides a new way for the synthesis of amino acid derivatives.Mechanistic studies have shown that the nitro group was transformed into amino group through two intramolecular MPV-O hydrogen transfer processes,and another substrate alcohol or amine acts as a nucleophile to attack the carbonyl group to form the target product.In addition,by employing dehydrogenation as a substrate-activating strategy,a series of incompletely aromatized coupling products were synthesized through the coupling reaction between two molecules of 1,2,3,4-tetrahydroquinoline derivatives by using CuCl as a catalyst and TBHP as an oxidant.Benzocycloamines,because of its ubiquitous presence in natural products,synthetic drugs,and fine chemicals,have important application value.This strategy undoubtedly provides a new idea for their derivatization.Mechanism studies indicate that the reaction undergoes a free radical process.Therefore,hydrogen transfer and dehydrogenation strategies can provide scientists with more green and efficient catalytic systems,thereby building amine compounds.