The sequential arrangement of multiple monomer units in a polymer chain remains a major challenge in synthetic chemistry. Here we describe a versatile route to the novel polyester-polythiocarbonate block copolymer from commercially available lactones, epoxides, and carbonyl sulfide (COS). A bicomponent organocatalyst combining triazabicyclodecene (TBD) with triethyl borane (TEB) generates two types of tunable active sites, i.e., TBD-capped alcohol via hydrogen bond and TEB-capped alcohol via O→B coordination bond, which can successively catalyze ring-opening polymerization of lactones and ring-opening copolymerization of COS and epoxides from mixed monomers in one pot. Because of the reversible activated propagating anions and fast activity exchange between the active and dormant species, all of the polymer chains are enchained with both polyester and polythiocarbonate blocks. Kinetic determination quantitatively confirms the proposed mechanism. This method enables diverse lactones and epoxides to form sulfur-containing block copolymers with readily tunable structures.

聚合物链中多个单体单元的顺序排列仍然是合成化学中的主要挑战。在这里，我们描述了从市售内酯，环氧化物和羰基硫（COS）到新型聚酯-聚硫代碳酸酯嵌段共聚物的通用途径。将三氮杂双环癸烯（TBD）与三乙基硼烷（TEB）结合使用的双组分有机催化剂可产生两种类型的可调活性位点，即通过氢键的TBD封端的醇和通过氢键的TEB封端的醇。O→B配位键，可在一锅中连续催化内酯的开环聚合以及COS和环氧化物的开环共聚反应。由于可逆的活化传播阴离子以及活性和休眠物种之间的快速活性交换，所有的聚合物链都被聚酯和聚硫代碳酸酯嵌段连接在一起。动力学测定定量证实了所提出的机理。该方法使各种内酯和环氧化物形成具有易于调节结构的含硫嵌段共聚物。