膦手性丙炔胺脯氨酸磷酸酯螺旋聚合物的合成与表征

通过添加对映体拆分剂,合成了4种含膦手性的丙炔胺磷酸酯单体HC帒CC H2NH(PO)R1R2].单体1,R1=OPh,R2=NC4H7COOCH3;单体2,R1=OPh,R2=NC4H7COOCH2CH3;单体3,R1=OPh,R2=NC4H7-COOC(CH3)3;单体4,R1=Ph,R2=NC4H7COOC(CH3)3].1H-NMR和31P-NMR表征可知对映体(单体1)不能被拆分剂拆分,而单体2、单体3、单体4通过拆分剂可以制得单一手性的磷化合物.以(nbd)Rh+η6-C6H5B--(C6H5)3]为催化剂,以三氯甲烷为溶剂成功得到聚合物分子量范围在0.4×10-4～0.7×10-4,分子量分布在1.26～1.98范围的3种含手性膦侧基的丙炔胺类聚合物.比旋光度(α]D)、圆二色谱(CD)对聚合物的不同侧基及温度对光学活性的影响表明,聚合物具有良好的光学活性且能够形成单一方向的螺旋构象,说明膦手性在构建螺旋聚合物具有重要作用.

SYNTHESIS AND CHARACTERIZATION OF PROPARGYLPHOSPHONAMIDE HELICAL POLYMERS

Phosphorus has a structure with five coordination,this compound is easy to form enantiomers and can hardly be separated.In this paper,four propargylphosphonamide monomers HCCCH2 NH(PO)-R1R2.Monomer 1:R1=OPh,R2=NC4H7COOCH3;monomer 2:R1=OPh,R2=NC4H7COOCH2CH3;monomer 3:R1=OPh,R2=NC4H7COOC(CH3)3 and monomer 4:R1=Ph,R2=NC4H7COOC(CH3)3] were designed and synthesized.1H-NMR and 31 P-NMR show that monomer 1 can only form enantiomer and cannot be separated.But monomer 2,monomer 3 and monomer 4 can be separated by resolving agent to form P-chiral diastereomeric monomers.Polymerization was carried out with(nbd)Rh+η6-C6H5B——(C6H5)3] as catalyst in CHCl3 giving four polymers with moderate molecular weights(Mn)(0.4×104~0.7×104) and Mw/Mn(1.26~1.98) by GPC,two factors(the pendent group and temperature) were observed to affect the helix structure of polymers.The optical activity and secondary structure of the polymers were characterized by specific rotations(α]D),circular dichroism(CD) spectra and UV-Vis.It shows that the polymers have good optical activity and can form a single direction of the helical conformation.It was found that the secondary structure stability of the copolymer is better than homopolymer's in different mixed solvents,when the methanol quantity was up to 50%,CD spectra of poly3 and poly4 change largely,which shows methanol broke the hydrogen bond between phosphorus-oxygen bond and nitrogen-hydrogen bond.