Polystyrene‐supported Pd(II) complex‐catalysed carboacylation of 2‐arylpyridines with alcohols via C─H bond activation under solvent‐free conditions

Abstract

Polystyrene‐supported N,N‐dimethylethylenediamine Pd(II) complex C was used as an efficient catalyst for the synthesis of aromatic ketones via ortho‐acylation of sp2 C─H bonds of 2‐arylpyridines with alcohols as effective coupling partners. The alcohols were oxidized with tert‐butyl hydroperoxide to their corresponding aldehydes in situ and efficiently coupled with 2‐arylpyridines to form aryl ketones under solvent‐free conditions. Furthermore, catalyst C could be easily recovered by simple filtration and reused for five cycles without any significant decrease in its activity.

Polymer‐Supported Palladium(II) Carbene Complexes: Catalytic Activity, Recyclability, and Selectivity in C−H Acetoxylation of Arenes

“…However, metal leaching, reduction of the Pd II species during preparation steps and catalysis and aggregation of Pd 0 nanoparticles inside the polymer matrixes remains an unsolved problem in many cases . However, although directed C−H activation over supported Pd complexes has been reported, there are no examples of the application of such catalysts for undirected C−H activation reactions …”

Circular Design and Functionalized Upcycling of Waste Commodity Polystyrene via C-H Activation Using Microwave-Assisted Multicomponent Synthesis

“…Functional derivatives of polystyrene have great value and application in water purification systems as ion-exchange resins or in biomedical applications as solid-phase support for peptide synthesis (Merrifield resin) [ 22 ], bovine serum separation, and purification or catalysis [ 23 ]. They are also actively used in organic synthesis [ 24 ], functionalized nanoparticles [ 25 ], electroactivity, and the emission and absorption of light [ 26 ], as well as for realizing green chemistries, including solvent-free synthesis, [ 27 ] click chemistry [ 28 , 29 ], cross-coupling reactions [ 30 ], ionic liquids grafting [ 31 ], laser and ultraviolet (UV)-based methods [ 32 ], and microwave-assisted synthesis [ 33 ]. However, these functional materials are synthesized from chloromethylated polystyrene synthesized from divinylbenzene [ 34 , 35 , 36 ], and functionalization occurs on the aromatic ring [ 37 ] due to the reactivity at this site [ 35 , 38 ].…”