In the pursuit of advanced functional polymer materials, polymers with fused heterocycles have received tremendous attention owing to their unique photoelectric properties, good thermal properties, stimuli-responsive properties, and high refractive indices. However, their synthesis mainly relies on fused heterocycle-containing monomers and precursors, which has hindered the exploration of new polymer materials. Herein, transition-metal-catalyst-free multicomponent polymerizations (MCPs) of diisocyanides, dialdehydes, and 2-aminopyridine in ethanol were developed, which were featured with high efficiency and specificity, high atom economy, environmental benefits, and product structural diversity. The MCPs could not only generate long polymer chains but also build the fused heterocycle, imidazo[1,2-a]pyridine, from simple monomers, demonstrating great synthetic efficiency and simplicity. Six imidazo[1,2-a]pyridine-containing polymers with high molecular weights (M_w up to 41,700 g/mol) were obtained in high yields (up to 98%), which generally possessed good solubility, high thermal stability, unique fluorescence property, and acid/base-triggered reversible fluorescence switch behavior. The MCPs have provided an effective approach for the construction of functional polymers with complex structures, which may accelerate the development of fused heterocyclic polymer materials.

中文翻译：

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异氰化物、醛和 2-氨基吡啶的多组分聚合制备含咪唑并[1,2-a]吡啶的稠合杂环聚合物

在追求先进功能聚合物材料的过程中，具有稠合杂环的聚合物由于其独特的光电性能、良好的热性能、刺激响应性能和高折射率而受到了极大的关注。然而，它们的合成主要依赖于稠合的含杂环单体和前体，阻碍了新型高分子材料的探索。在此，开发了二异氰化物、二醛和2-氨基吡啶在乙醇中的无过渡金属催化剂多组分聚合（MCPs），具有高效和特异性、高原子经济性、环境效益和产品结构多样性等特点。MCPs 不仅可以生成长聚合物链，还可以构建稠合杂环，咪唑并[1,2- a]吡啶，来自简单的单体，表现出极大的合成效率和简单性。以高收率（高达 98%）获得了六种具有高分子量（M _w高达 41,700 g/mol）的含咪唑并[1,2 - a ]吡啶聚合物，它们普遍具有良好的溶解性、高热稳定性、独特的荧光特性和酸/碱触发的可逆荧光开关行为。MCPs为构建具有复杂结构的功能聚合物提供了一种有效的途径，可能会加速稠合杂环聚合物材料的发展。