One-pot Synthesis Of Chiral Phenethylamine Based On Asymmetric Transfer Hydrogenation And Dynamic Kinetic Resolution To Construct Chiral Phenethylamine

Chiral alcohols and chiral amines are very important compounds,which have been used in medicine and daily cosmetics.Their synthesis and enrichment are also the goal of scientists' continuous exploration.Firstly,asymmetric transfer hydrogenation(ATH)is proposed to obtain chiral benzenethanols.ATH uses sodium formate as hydrogen source,which is safer than the unstable hydrogen used in asymmetric hydrogenation.Secondly,chiral phenylethylamine compounds were obtained by dynamic kinetic resolution.In addition,the two methods in this paper both involve biological enzyme catalysis,which is more in line with atomic economics and meet the characteristics of green environmental protection,and more in line with the requirements of "green chemistry".In the first part,chiral benzyl alcohol was obtained from racemic benzyl alcohol by means of one pot oxidation/asymmetric transfer hydrogenation series reaction.The specific process was as follows: firstly,laccase /TEMPO system was used for the oxidation of benzene ethanol.Due to the specificity of biological enzyme,the reaction was thorough.Then,asymmetric transfer hydrogenation catalyst and sodium formate were added to the system for ATH reaction.The substrate expansion of the system was also carried out,and the highest yield reached 97%,and the enantiomer equivalent was also at a high value,with the highest 97% and the lowest 80%.In the second part,chiral phenylacetamide was obtained from racemic phenylethylamine by dynamic kinetic resolution.For the specific process,the design and synthesis of heterogeneous despun Pd catalyst @ PMOs transistor,and the catalysts were characterized,and tested the despun reaction were verified the correctness of the catalyst,after screening the reaction conditions,with candida Antarctica lipase B(Cal B)concerted catalysis,has carried on the dynamic kinetic resolution of phenethylamine reaction,The high yield(83%)and high enantioselectivity(EE value 99%)benzoacetamide was obtained by breaking the 50%yield limit of conventional kinetic resolution,and the derivatization experiments were carried out,which also proved the universality of the catalytic system.