Synthesis of Vinylene-Linked Covalent Organic Frameworks from Acetonitrile: Combining Cyclotrimerization and Aldol Condensation in One Pot

Combining two or more consecutive reactions in one pot is a common approach for process development, as such a method involves cheap starting materials and allows in situ generation of a reactive intermediate, to undergo further reaction, without isolation. Herein, we report the synthesis of a vinylene-linked (−CH═CH−) covalent organic framework, COF-701, directly from acetonitrile, a cheap commodity solvent, by combining/telescoping two consecutive reactions—cyclotrimerization of nitrile and subsequent aldol condensation with aldehydes—in one pot. Acetonitrile is trimerized to generate protonated 2,4,6-trimethyl-s-triazine tautomers in situ, which undergo Aldol condensation with 4,4′-biphenyldicarbaldehyde in one pot to form crystalline COF-701. COF-701 is obtained as a polycrystalline powder and possesses permanent microporosity and a BET surface area (SA BET ) of 736 m 2 ·g –1 . This strategy can be further extended to generate other porous vinylene-linked frameworks.