Synthesis Of Helical Poly(phenylacetylene) Derivatives And Their Resolution Ability As Chiral Stationary Phase

In this work, N-（4-ethynylphenylamidyl）-L-leucine ethyl ester （PACL） and3-（N-（4-ethy-nyl phenylamidyl））-aminopropyltriethoxysilane （PACS） were designed and synthesized，thencharacterized by¹H NMR. Another monomer N-（4-ethynylphenylureayl）-leucine ethyl ester（PAUL） was used directly. Poly（N-（4-ethynylphenylureayl）-leucine ethyl ester）（HP-PAUL）,poly（N-（4-ethynylphenylamidyl）-L-leucine ethyl ester）（HP-PACL）, copoly（（N-（4-ethynylphenylamidyl）-L-leucine ethyl ester））（CP-PACL） and thermal polymer （TP-PACL）were produced by several kinds of polymeration. These polymers were charactered through¹H NMR spectrum. The Mnand Mw/Mnwere tested by GPC. The properties of the polymers,such as Cotton effect and chiral separation ability as chiral stationary phases （CSPs）, wereresearched by TG, OR, CD and HPLC.Firstly, the monomers PACL and PACS were prepared with Sonagashira couplingreaction and elimitation reation, esterification reaction, amidation reation. The structure andpurity of monomers was confirmed by^<sup>1H NMR. Rh（nbd）[BPh4] was used as castalyst toobtain polymer HP-PAUL and HP-PACL, and PACL was polymered to obtain TP-PACL inhigh temperature. Through the test of OR and CD sepctrun, effect of the solvents and additionof ammonium salts to helial chain regularity of polymers was tested. The results showed thatpolymers HP-PAUL and HP-PACL had strong optically active property and controlled helicalconformation of chain, and TP-PACL possessed no chain helical regularity and belonged tothe nonhelical polymers.Secondly, serval coated CSPs were prepared with the two kinds of homopolymers. Theeffect of coating solvents to the chiral separation ability was tested. The results showed TheCPMs of HP-PAUL had poor chiral resolution to the racemates, coated with THF, DMF orDMAc. CSPs TP-PACL showed no chiral recognition ability in HPLC. CSPs HP-PACLcoated with FCHCl₃showed best chiral recognition ability in HPLC among the apronticsolvents. Prontic solvent MeOH greatly improved the chiral recognition ability. The effect ofMeOH in mixture coating solvent including MeOH and CHCl₃was tested by¹H NMR, tostudy the mechanism of effect of prontic solvent to chiral recognition ability. The CSPsHP-PACL coated with mixed solvent （MeOH/CHCl₃,3/7, v/v） showed the best chiralrecognition ability. Finally, copolymeration of PACL and PACS was used to produce CP-PACL. ImmobiledCSPs CP-PACL were prepared by immobiled reaction that provided the influence of theaddition of PACS to immobiled efficiency.The CSPs was immobiled on the surface of silicalgel, which was designed as a novel method to immobization of chiral separation phases.Effect of the proportion of PACS and ammonium salts to chiral resolution ability was tested.The results showed that immobiled efficiency increased and chiral separation abilitydeminished with the increasing propertion of PACS. The addition of ammonium salt TBAAgreatly improved the chiral separation ability of immobiled-type CSPs CP-PACL.