Extending the 2D conjugated microporous polymers linked by thiazolo[5,4-d]thiazole for green light-driven selective aerobic oxidation of amines

Abstract

Conjugated microporous polymers (CMPs) have emerged as multifaceted photocatalysts whose properties can be precisely tuned at the molecular level. Herein, donor–π–acceptor (D–π–A) type CMPs linked by the electron-deficient thiazolo[5,4-d]thiazole (TzTz, i.e. the acceptor) were designed by extending the donor from benzene to pyrene to broaden the visible light activity. Subsequently, two-dimensional (2D) CMPs, TzTz–CMP–Be and TzTz–CMP–Py, were constructed via a solvothermal process. Notably, the more extended π-conjugation and planar pyrene bestow upon TzTz–CMP–Py with broader absorption of visible light and higher efficiency of charge transfer than TzTz–CMP–Be. Significantly, TzTz–CMP–Py outperformed TzTz–CMP–Be in the green light-driven selective aerobic oxidation of amines. Remarkable photocatalytic performance was observed in converting a wealth of primary and secondary amines to corresponding imines with molecular oxygen (O₂) over TzTz–CMP–Py. This work suggests that CMPs can be rationally designed for extensive visible light-driven selective organic transformations.