Premium
Single‐Pore versus Dual‐Pore Bipyridine‐Based Covalent–Organic Frameworks: An Insight into the Heterogeneous Catalytic Activity for Selective CH Functionalization
Author(s) -
Vardhan Harsh,
AlEnizi Abdullah M.,
Nafady Ayman,
Pan Yanxiong,
Yang Zhongyu,
Gutiérrez Humberto R.,
Han Xiaolong,
Ma Shengqian
Publication year - 2021
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202003970
Subject(s) - imine , surface modification , catalysis , covalent bond , bipyridine , steric effects , palladium , materials science , covalent organic framework , chemistry , combinatorial chemistry , polymer chemistry , organic chemistry , crystal structure
Exponential growth in the field of covalent–organic frameworks (COFs) is emanating from the direct correlation between designing principles and desired properties. The comparison of catalytic activity between single‐pore and dual‐pore COFs is of importance to establish structure–function relationship. Herein, the synthesis of imine‐linked dual‐pore [(BPyDC)] x % ‐ETTA COFs ( x = 0%, 25%, 50%, 75%, 100%) with controllable bipyridine content is fulfilled by three‐component condensation of 4,4′,4″,4′″‐(ethene‐1,1,2,2‐tetrayl)tetraaniline (ETTA), 4,4′‐biphenyldialdehyde, and 2,2′‐bipyridyl‐5,5′‐dialdehyde in different stoichiometric ratio. The strong coordination of bipyridine moieties of [(BPyDC)] x % ‐ETTA COFs with palladium imparts efficient catalytic active sites for selective functionalization of sp 2 CH bond to CX (X = Br, Cl) or CO bonds in good yield. To broaden the scope of regioselective CH functionalization, a wide range of electronically and sterically substituted substrates under optimized catalytic condition are investigated. A comparison of the catalytic activity of palladium decorated dual‐pore frameworks with single‐pore imine‐linked Pd(II) @ Py‐2,2′‐BPyDC framework is undertaken. The finding of this work provides a sporadic example of chelation‐assisted CH functionalization and disclosed an in‐depth comparison of the relationship between superior catalytic activity and core properties of rationally designed imine linked frameworks.