Synthesis Of Chiral Cyclometalated Complexes And Their Applications In Asymmetric Hydrophosphination Reactions

Chiral phosphine compounds have broad applications in the pharmaceutical industry as both active pharmaceutical ingredients and ligands for asymmetric reactions.Asymmetric hydrophosphination provides a one-step synthesis of chiral phosphine compounds from achiral starting materials with high atom efficiency.The structure of the catalyst plays a critical role in achieving high efficiency and selectivity in the reaction.The purpose of this paper is to study the method and mechanism of using chiral cyclometalated complexes to catalyze the synthesis of chiral phosphine compounds by asymmetric hydrophosphination,to explore the influence of reaction conditions,catalyst selection in the reaction system,the influence of coordination groups and other factors on the reaction,and to characterize and evaluate the synthesized chiral phosphine compounds.Through this study,new ideas and methods can be provided for the synthesis of chiral phosphine compounds1,In this study,we synthesized 8 chiral cyclometalated complexes by oxidative addition of halogenated aromatic compounds with Pd or Ni metals.The synthesized complexes were characterized by NMR,X-ray crystallography,and high-resolution mass spectrometry.2,We then evaluated the catalytic ability of these complexes in the asymmetric hydrophosphination of phenylphosphine and various trans-chalcones.We found that a palladium complex with a N-heterocyclic carbene(NHC-Pd-C,P-ring)showed the best performance under optimized reaction conditions(-20℃,K2CO3 as base,CH2Cl2 as solvent).The catalyst exhibited high yields and enantioselectivities for the synthesis of chiral phosphine products with different types of trans-chalcones.3,Finally,we tested the catalytic ability of these complexes in the asymmetric hydrophosphination of diphenylphosphine and various trans-chalcone.Thepalladium c yclometalated complex showed high efficiency in this reaction under optimized conditions(0℃,KO Ac as a base,THF as a solvent).Most of them tested produced chiral phosphine produ cts with near-quantitative yield and 99%enantiomeric excess.This study provides a new approach and method for the synthesis of chiral phosphine compounds and offers insights into the factors affecting the efficiency and selectivity of the reaction.