A Ru-Complex Tethered to a N-Rich Covalent Triazine Framework for Tandem Aerobic Oxidation-Knoevenagel Condensation Reactions

Abstract

Herein, a highly N-rich covalent triazine framework (CTF) is applied as support for a RuIII complex. The bipyridine sites within the CTF provide excellent anchoring points for the [Ru(acac)2(CH3CN)2]PF6 complex. The obtained robust RuIII@bipy-CTF material was applied for the selective tandem aerobic oxidation–Knoevenagel condensation reaction. The presented system shows a high catalytic performance (>80% conversion of alcohols to α, β-unsaturated nitriles) without the use of expensive noble metals. The bipy-CTF not only acts as the catalyst support but also provides the active sites for both aerobic oxidation and Knoevenagel condensation reactions. This work highlights a new perspective for the development of highly efficient and robust heterogeneous catalysts applying CTFs for cascade catalysis.

A Porphyrin-Based Covalent Organic Framework as Metal-Free Visible-LED-Light Photocatalyst for One-Pot Tandem Benzyl Alcohol Oxidation/Knoevenagel Condensation

“…Tandem reactions usually require multifunctional catalysts that are able to promote more than one single reaction [ 30 ]. The formation of a carbon–carbon bond through the selective aerobic oxidation of alcohols and consecutive Knoevenagel condensation reaction is one of the most fundamental transformations in organic chemistry [ 31 , 32 , 33 , 34 ]. In this context, various heterogeneous catalysts have been reported but possess numerous shortcomings, including poor stability, precious metals, and/or metal contamination, thereby hampering their practical applications [ 7 , 8 , 35 , 36 ].…”

Efficient Visible Light Active Photocatalyst: Magnesium Oxide-Doped Graphitic Carbon Nitride for the Knoevenagel Condensation Reaction

“…During the past few years, light-assisted organic synthesis has grown rapidly. , One of the most fundamental transformations in organic chemistry is the formation of a carbon–carbon bond in Knoevenagel condensation reactions. − Many classical acid–base or base-catalyzed heterogeneous systems have been reported in this context. − Despite their advantages, these systems suffer from numerous drawbacks such as high temperatures, longer reaction times, poor selectivity, and low energy efficiency; therefore, they are not practical. Thus, it is imperative to develop heterogeneous photocatalytic systems that are greener, more efficient, and more sustainable.…”

Chitosan bead containing metal–organic framework encapsulated heteropolyacid as an efficient catalyst for cascade condensation reaction

“…In this regard, cascade reactions 2 that combine consecutive synthetic steps in one-pot and benefit from advantages, such as less energy consumption, less waste production and avoiding intermediate separation and purification are great tools for developing sustainable chemistry. To promote cascade reactions, multifunctional catalysts are required 3 , in which several catalytic active sites are introduced on a recyclable supporting material. In this context, wise choice of the support and immobilization strategy can provide synergistic effects and furnish catalysts with high efficiency.…”