Mono-functionalization of porous aromatic frameworks to use as compatible heterogeneous catalysts in one-pot cascade reactions

Abstract

Porous aromatic frameworks (PPAFs) prepared by microwave assisted synthesis can be easily functionalized to obtain solid acid (sulfonic acid) and base (primary amine) catalysts. This porous material demonstrated to be an excellent support of different functional groups. The combination of these functionalized PPAFs was successfully applied as compatible heterogeneous catalysts for cascade reaction of hydrolysis of dimethoxymethylbenzene, acid catalyzed, and Knoevenagel catalyzed by base. The advantages of this catalytic system are its easy synthesis, good catalytic activity, coexistence of incompatible functional groups in homogeneous conditions, with different acid/base ratio, and is recycled up seven times without significant loss of activity. Our concept can be extended to other various one-pot incompatible homogeneous systems and make a contribution toward the creation of environmentally inspired chemical processes through the promotion of multiple reactions in a single reactor. © 2013 Elsevier B.V. All rights reserved.