有机催化实现含硫高分子的精确合成

Metal-free Access to Precise Synthesis of Sulfur-containing Polymers

脂肪族含硫高分子是一类重要的功能聚合物材料.催化含硫一碳化合物(氧硫化碳(COS)、二硫化碳(CS2))与环氧化物共聚制备含硫高分子是近年迅速发展起来的合成路线.最近,张兴宏等使用由有机Lewis碱和硫脲构成的无金属催化体系,实现了COS与环氧化合物室温"活性"阴离子共聚,得到了100%交替、头尾结构含量>99%、数均分子量近1×105和窄分布(1.13~1.23)的聚单硫代碳酸酯,催化剂活性达112 h-1,揭示了硫脲和Lewis碱分别选择性活化环氧和COS并协同催化共聚的反应机制.

Sulfur-containing polymers are important functional materials and can be used as optical, anticorrosion and antifouling materials. Using C1 monomers（i.e. carbonyl sulfide（COS）, carbon disulfide（CS2）） to copolymerize with epoxides have been rapidly developed in very recent years. Recently, Xing-Hong Zhang et al.reported a metal-free living copolymerization of COS with epoxides via the cooperative catalysis of organic Lewis pairs including organic bases and thioureas as hydrogen-bond donors, afforded poly（monothiocarbonate）s with100% alternating degree, 〉99% tail-to-head content, high molecular weight（up to 9.84 × 105） and narrow molecular weight distributions（1.13 – 1.23）. The turnover frequencies（TOFs） of the catalyst are as high as112 h-1 at 25 °C. Kinetic and mechanistic results suggest that the supramolecular specific recognition of thiourea to epoxide and base to COS promoted the copolymerization cooperatively. The synthesis of sulfur-containing polymer developed by Xing-Hong Zhang and co-workers is very promising to the utilization of C1 monomers derived from the use of oil and coal.