Synthesis Of Chiral Phosphoryloxy Organic Luminescent Materials

Circularly polarized luminescent(CPL)materials have great potential applications in areas such as biological probes,information storage,3D displays,CPL sensors,and CPL lasers.Thus,the development and application of such materials is a current research hotspot in the field of organic synthesis and materials.In comparison to chiral complexes of transition metals,organic small molecules are considered ideal CPL materials because they are easier to synthesize,modify and derivatize,and therefore,can facilitate a more accurate study of the relationship between structure and performance.Moreover,they exhibit high luminous efficiency and the emission wavelength can be adjusted.In the past few decades,the research on central chiral CPL organic small molecules has mainly focused on carbon-centered chiral CPL organic small molecules,while there are no reports on phosphine-centered chiral CPL materials due to the lack of efficient methods for constructing such compounds.In this work,we aimed to explore a simple and efficient way to construct phosphine-centered chiral organic small molecules and synthesize new CPL materials.Based on the above,we utilized cheap metal nickel to catalyze and have realized the asymmetric cross-coupling reaction of racemic secondary phosphine oxides with alkenyl bromides or aryl bromides,The reaction underwent a kinetic resolution process,and a series of phosphine-centered chiral compounds were obtained with excellent yield and excellent enantioselectivity.This method has mild reaction conditions,good tolerance of functional groups,cheap and easy to obtain raw materials,and a wide range of substrates.At the same time,using this method,we simply and efficiently introduced the chirality of the phosphine center into the pyrene-based luminescent group to synthesize the phosphine-centered chiral CPL small molecule material.1.We used nickel catalyst and ferrocene-based chiral nitrogen-phosphorus ligand,KOAc as a base,and used alkenyl bromide to perform kinetic resolution of racemic secondary phosphine oxides.A series of phosphine-centered chiral alkenyl phosphine oxides were obtained with excellent yield and enantioselectivity,and phosphine-centered chiral secondary phosphine oxides were recovered.This work provides a new method for the construction of the important skeleton of phosphorus-centered chiral alkenylphosphine oxides,which is helpful for its further derivative applications.2.On the basis of the first part of the study,we further optimized the reaction conditions,using K2HPO4 as base,ethyl acetate as solvent,at 40℃,the asymmetric cross-coupling reaction of tert-butylphosphine oxide and aryl bromide was realized.This work provides a new strategy for the construction of phosphorus-centered chiral phosphine oxides and has great application potential in the synthesis of phosphorus chiral ligands.3.We successfully introduced the pyrene-based luminescent group and synthesized the phosphorus-centered chiral circularly polarized luminescent molecule S-5zi and its enantiomers by using the catalytic method developed by ourselves.The optical properties of UV-visible light,fluorescence,CD and CPL were studied,showing the potential application value of phosphorus-centered chiral luminescent small molecules in the field of CPL materials.