Synthesis Of Novel Chiral Tridentate Pincer Metal Complexes And Their Application In Asymmetric Catalytic Reactions

Chiral tridentate pincer metal complexes have attracted much attention in organic synthesis and green chemistry due to their good stability and easy modification.By adjusting the structure of chiral tridentate pincer ligands and choosing different metals are the two main ways for chiral tridentate pincer metal complexes to improve reactivity and stereoselectivity in asymmetric catalytic reactions.The asymmetric phosphine hydrogen addition reaction has always been one of the research hotspots in the field of asymmetric catalysis due to its good atom economy and potential applications.This paper mainly focused on the synthesis of novel chiral pincer metal complexes and their application in asymmetric catalytic synthesis of chiral phosphine compounds,as follows:1.Different types of chiral tridentate pincer ligands(including PCN type and PCP type)were designed and synthesized by using the synthesis method of chiral phosphine compounds developed by our group.After further carbon metalization process,9 chiral tridentate pincer metal complexes were finally synthesized.We also performed various basic data characterization of the synthesized chiral pincer metal complexes,including hydrogen,carbon and phosphorus spectrum,X-Ray single crystal diffraction and high resolution mass spectrometry analysis.2.Application of novel chiral tridentate pincer metal complexes in asymmetrically catalyzed addition reaction of diphenylphosphine and electron-deficient ketene.In the presence of 10%potassium acetate and a reaction temperature of-20℃,the new chiral pincer PCN-nickel complexes catalyzes the asymmetric addition reaction of diphenylphosphine and electron-deficient ketene in MeCN solvent,with an excellent yield of up to 99%and an excellent enantioselectivity of up to 99%ee synthesis of chiral phosphine compounds with a carbon chiral center.3.Application of new chiral tridentate pincer metal complexes in the asymmetric catalysis of the addition reaction of phenylphosphine and electron-deficient ketene.In the presence of 10%potassium acetate and a reaction temperature of-40℃,the new chiral pincer PCP-nickel complexes catalyzes the asymmetric addition reaction of phenylphosphine and electron-deficient ketene in DCM solvent,with an excellent yield of up to 92%and an excellent enantioselectivity of up to 99%ee and stereoselectivity greater than 20:1 generate chiral phosphine compounds with the phosphine and carbon chiral centers,which provides an efficient and convenient way to obtain chiral phosphine compounds.