C(sp³)–H Polyamination of Internal Alkynes toward Regio- and Stereoregular Functional Poly(allylic tertiary amine)s

The heteroatom-containing polymers are important components of advanced functional materials. Among the tremendous synthetic methodologies, polymerization via C–H activation is a powerful tool for the preparation of functional heteroatom-containing polymers, which should be further enriched, especially via C(sp3)–H activation. In this work, a new atom economic Pd(0)/benzoic acid catalyzed polymerization of internal diynes and secondary diamines via C(sp3)–H activation; i.e., C(sp3)–H polyamination of internal alkynes was successfully established. A series of regio- and stereoregular functional poly(allylic tertiary amine)s with high weight-average molecular weights (Mw, up to 25 600) were synthesized in excellent yields (up to 98%). The resultant polymers possess good solubility and film-forming ability, and their thin films exhibit high refraction indices (RI) with the range of 1.7207–1.6797 at 632.8 nm. Moreover, all the poly(allylic tertiary amine)s are emissive in solution and solid states. Thanks to the tolerance to functional groups of this polymerization, the tetraphenylethene (TPE) moiety could be facilely incorporated to endow the resultant polymers with the unique aggregation-enhanced emission (AEE) characteristics. Thus, this work not only establishes a powerful C(sp3)–H polyamination but also provides a strategy to facilely prepare functional nitrogen-containing acetylenic polymers.