“On Water” Effect for Green Click Reaction: Spontaneous Polymerization of Activated Alkyne with “Inert” Aromatic Amine in Aqueous Media

Organic reactions in water have attracted great attention due to their advantages such as unique reaction performance and environmental friendliness. Organic reactions as well as polymerizations in aqueous media have been extensively investigated, and so far, there has been a massive amount of reporting about polymerizations in water. However, reports about click polymerization in water have been rare. Herein, click polymerization of activated alkyne and aromatic amine in aqueous media is developed. The “on water” effect facilitates polymerization in aqueous media better than in organic solvents, and its mechanism is deciphered through experimental data and theoretical calculations. Water participates in the reaction and reduces the energy barrier to some extent. Besides, polymerization makes it possible for aromatic amine with low reactivity to be linked. By using this strategy, polymers with high molecular weights can be obtained in high yields (up to 95.4%). They show good thermal stability and high refractivity. They can be photodegraded. The polymers with tetraphenylethylene moieties show aggregation-induced emission and can be used as materials for generating photopatterns and visualizing agents for specific staining of lysosome in living cells.