Synthesis Of Novel Atropisomeric Bisphosphine Ligands And Their Applications In Asymmetric Hydrogenation

In the research process of asymmetric catalytic hydrogenation synthesis,the existence of chiral catalyst is the reason for the high efficiency and high selectivity of the reaction.Chiral phosphorus ligands are an important part of catalysts and have been extensively studied,with atropisomeric bisphosphine ligands as the most.However,most of the atropisomeric bisphosphine ligands based on biphenyls or binaphthalenes have long synthesis steps and low yields,and the industrial application value is greatly reduced.Therefore,a new class of novel atropisomeric bisphosphine ligands is designed which have high yields,and have high efficiency and high selectivity.It is very necessary for industrial application.This study analyzes the reasons for the difficulty in the synthesis of atropisomeric bisphosphine ligands.Based on the design concept and synthetic route of NUPHOS,a new type of novel atropisomeric bisphosphine ligands was designed and synthesized using metallacycle transfer from zirconium and dialkyne cyclization.The specific research content is as follows: Using(R,R)-1,2-cycloxylene as raw materials,two new ligands were synthesized t hrough three-step or four-step reaction,reaching 66% yield.When acetophenone is used as the reaction substrate,only when the new ligand is made into a bisphosphine diamine catalytic system,the asymmetric reduction of the catalytic hydrogenation of acetophenone and its derivatives has achieved good results,reachi ng a catalytic activity comparable to the BINAP bisphosphine diamine catalyst system.2-pivalamido-1-indanone is the standard substrate.The catalytic activity and enantioselectivity of new ligands are detected and good results are obtained by asymmetric reduction.The conversion rate reaches 99%,and the product are obtained with 96% ee.They are very useful chiral amino ketone compounds in organic synthesis.The application scope of the reaction substrate is expanded.The asymmetric catalytic hydrogenation experiment of 16 substrates is completed,and the enantiomeric excess of the product can reach 99% ee.