Copper-Catalyzed Polycoupling of Diynes, Primary Amines, and Aldehydes: A New One-Pot Multicomponent Polymerization Tool to Functional Polymers

Development of new methodology for the preparation of functional polymers with practical applications is a fundamental important research area in macromolecular science. In this paper, a new polymerization route for the synthesis of functional polymers is developed. The three-component polycoupling reactions of diynes [HC≡C–R–C≡CH, R = (C6H5)2C═C(C6H5)2, (C6H5)4SiC4(C4H9)2, (C6H5)4SiC4(C6H5)2, C12H8(OCH2)2, (CH2)4], primary amines, and aldehydes are catalyzed by copper(I) chloride in toluene at 100 °C for 2 h, affording soluble and regular poly(dipropargyl amine)s (PDAs) with high molecular weights (Mw up to 43 800) in high yields (up to 89%). The polymerization reaction is insensitive to moisture. All the PDAs are thermally stable and film forming. Their thin films show good optical transparency and high refractive indices (RI = 1.8322–1.7458) with low optical dispersions (D down to 0.0117). The tetraphenylethene or silole-containing PDAs exhibit a phenomenon of aggregation-induced emission. The PDAs are photosensitive and cross-link upon UV irradiation, generating negative photoresist fluorescent patterns. The polymer aggregates can function as sensitive fluorescent chemosensors for detecting explosives, such as picric acid, 2,4-dinitrotoluene, and 4-nitrobenzoyl chloride, with large quenching constants of up to 2.7 × 105 L/mol.