Study On The Tandem Reaction Of Synthetic Anthracenyl Esters And Chiral 3-Substituted

In the last hundred years,people pay high attention to organic synthetic chemistry for the reason that it can provide us drugs,materials and other necessities in our daily life.However,the development of organic synthetic chemistry also results in heavy environmental pollution,and the huge waste of resources and energy,etc.Thus,it is important to develop highly efficient,green and atom-economical synthetic methodologies in modern organic synthetic chemistry.There is no doubt that tandem reaction can be one efficient methodology to solve the problems of low yield,time consuming and cumbersome steps in organic synthesis.Tandem reactions are sequences of chemical transformations in which the starting substrate is designed to undergo a reaction whose product becomes the substrate for the next step,and whose product again becomes the substrate for the next step,and so on,until a product stable to the reaction conditions is reached.Here we report two new tandem organic reactions.Firstly,we developed a novel three-step tandem reaction containing intra-molecular Friedel-Crafts acylation,enolization and esterification.Bulky anthracenyl esters could be simply approached by the efficient reaction from 2-benzylbenzoic acids in the presence of TCT,pyridine and AICl3.Secondly,a chiral thiophosphoramide ligand 35d was applied as an efficient chiral ligand in the catalytic asymmetric arylation reactions of varied aromatic aldehydes.Under the optimum reaction conditions,the diaryl alcohol product could be obtained with up to 98%yield and 98%ee value.35d could be quantitatively recovered and reused without the loss of catalytic efficiency.Thirdly,using chiral phosphoramide ligand 42d as the catalyst,we developed efficient catalytic asymmetric 1,2-addition/lactonization tandem reactions of diverse organozinc reagents with varied methyl 2-formylbenzoates for the construction of optically enriched 3-aryl or alkyl substituted phthalides,which are significant building blocks of many important chiral pharmaceuticals and nature products.Under the optimum reaction conditions,the final product could be obtained with up to 95%yield and 87%ee value.