Building N -hydroxyphthalimide organocatalytic sites into a covalent organic framework for metal-free and selective oxidation of silanes.

A novel crystalline covalent organic framework COF-NHPI was built by a bottom-up strategy to guarantee highly ordered embedment of the N -hydroxyphthalimide (NHPI) units as nitroxyl radical organocatalytic sites. The COF-NHPI was demonstrated to be a metal-free, highly selective and heterogeneous catalyst for the efficient oxidation of various silanes to the corresponding silanols. Mechanistic studies revealed that the critical phthalimido N -oxyl radical was generated in situ to govern the catalysis.