An Ionic Liquid on a Porous Organic Framework Support: A Recyclable Catalyst for the Knoevenagel Condensation in an Aqueous System.

Porous aromatic frameworks (PAFs) that feature a high density of phenyl rings in their robust frameworks are attractive platforms for catalysis because of their extremely high stability, high surface area, and adjustable pore size. In this paper, two PAF-supported ionic liquids were constructed by introducing ionic liquid units onto the framework of a PAF material PAF-111 using a series of stepwise post-synthetic modifications. The basic PAF-supported ionic liquid with a hydroxy anion exhibited high catalytic activity and high stability, and could undergo at least 10 cycles without any activity loss when catalyzing Knoevenagel condensation reaction under aqueous conditions. It is expected that our study will further promote the development of designing and applying functional PAF materials for catalysis in aqueous systems.