Benzimidazole‐Containing Porous Organic Polymers as Highly Active Heterogeneous Solid‐Base Catalysts

Abstract

To develop efficient heterogeneous catalytic systems for base‐catalyzed reactions, two benzimidazole‐containing porous organic polymers, BPOP‐1 and BPOP‐2, were synthesized. As a result of the difference in building units, BPOP‐1 exhibits a granular morphology, and BPOP‐2 is composed of tiny particles. N2 adsorption measurements show that BPOP‐1 is a nonporous framework, whereas BPOP‐2 displays good adsorption abilities towards N2, H2, and CO2. Both BPOP‐1 and BPOP‐2 exhibit a higher catalytic activity in the Knoevenagel condensation reaction than their homogeneous molecular counterpart, and the activity of BPOP‐2 is superior to that of BPOP‐1. Theoretical calculations show that the Lewis basicity of the N atoms in BPOP‐1 is identical to that in BPOP‐2. The prominent catalytic performance of BPOP‐2 is mainly attributed to its high specific surface area and microporous character. Moreover, the permanent chemical stability of the structural framework endows BPOP‐2 with an outstanding recyclability.

One‐Pot Synthesis of Polyhydroquinoline Derivatives through Organic‐Solid‐Acid‐Catalyzed Hantzsch Condensation Reaction

“…The synthesized PPN polymer shows a strong signal at δ =132.25 ppm, which is attributed to the nonsubstituted carbons of the aromatic rings. The two strong signals at δ =150.23 ppm and δ =141.23 ppm arise from the N‐substituted aromatic carbon atoms of triphenylamine and C‐substituted aromatic carbon atoms, respectively . The additional signal at δ =42 ppm is attributed to the carbon atom of the methylene linker.…”

Design and Catalytic Application of Functional Porous Organic Polymers: Opportunities and Challenges

“…Pd@CPP‐C and Pd@CPP‐Y showed H 2 uptake of 2.10 and 1.87 mmol g −1 , respectively. A large number of preparation methods have been developed for the efficient synthesis of POPs . Apart from this the post‐synthetic modification of the organic functional groups has been explored by numerous research groups in order to examine the inherent extraordinary stability of the as‐prepared POPs.…”

Water-stable fluorinated metal–organic frameworks (F-MOFs) with hydrophobic properties as efficient and highly active heterogeneous catalysts in aqueous solution

“…It is the most popular reaction used to investigate coordination polymers and MOFs containing basic functionalized structures. Furthermore, it is one of the most important reactions for the formation of C=C bond, for the synthesis of several fine chemicals and medical intermediates, In general, it is a highly useful reaction in synthetic chemistry [20][21][22][23][24][25][26][27][28].…”