Ethynylsulfone-Based Spontaneous Amino-yne Click Polymerization: A Facile Tool toward Regio- and Stereoregular Dynamic Polymers

Development of efficient polymerizations is crucial for polymer science from which polymeric materials with versatile properties could be produced. In this work, a new and efficient spontaneous amino-yne click polymerization is successfully established by using activated diynes of bis(ethynylsulfone)s. Compared with the ester-activated diynes, that is, dipropiolates, bis(ethynylsulfone)s could polymerize with all kinds of diamines including aliphatic and aromatic primary and secondary ones under very mild reaction conditions, and soluble and thermally stable poly(β-aminovinylsulfone)s (PAVSs) with high weight-average molecular weights (Mw up to 160,000) and excellent regio- and stereoregularity (the ratio of E isomers up to 100%) were obtained in high yields (up to 99%). Due to the strong electron-withdrawing ability of sulfonyl groups, the resultant PAVSs show a dynamic property and could undergo the amine exchange, which makes the polymers readily degrade upon addition of monoamines. Moreover, this highly efficient spontaneous amino-yne click reaction could be used to facilely label and decorate proteins. Thus, this work not only establishes a more efficient amino-yne click polymerization, which could be used to label bioconjugates, but also provides a novel strategy to construct regio- and stereoregular dynamic polymers.