Ligandless heterogeneous palladium: an efficient and recyclable catalyst for Suzuki‐type cross‐coupling reaction

Abstract

A mild and efficient ligand‐free Suzuki‐type cross‐coupling reaction of benzoyl chlorides and arylboronic acids catalyzed by heterogeneous Pd/C was developed. Benzoyl chlorides undergo cross‐coupling with electronically diverse arylboronic acids to give biaryl ketones in excellent yield, under aqueous media and optimum temperature. The application of 3 mol% of 10 wt% Pd/C to the cross‐coupling delivers utmost efficiency, and could be reused up to many consecutive cycles without any loss in activity. This method proceeds under aqueous media and a recyclable catalytic system, offering an environmentally benign alternative to the existing protocols. Copyright © 2014 John Wiley & Sons, Ltd.

Intercalation of copper salt to montmorillonite K‐10 and its application as a reusable catalyst for Chan–Lam cross‐coupling reaction

“…The hot reaction mixture was filtered to remove the Cu(II)@MMT catalyst, the filtrate was allowed to further react and the progress of the reaction was monitored by TLC. Product formation was observed in the filtrate, which suggests a quasi‐homogeneous process with a reversible dissolution–precipitation of Cu(II) species during the course of the reaction …”

“…Product formation was observed in the filtrate, which suggests a quasi-homogeneous process with a reversible dissolution-precipitation of Cu(II) species during the course of the reaction. [46,47] To further confirm the structural stability and reusability of Cu(II)@MMT in the C-N coupling reaction, the recovered catalyst was characterized using powder XRD and field emission SEM. The powder XRD pattern of the sample was recorded over a 2θ range of 10-80 ( Figure 5a).…”

A versatile method for the synthesis of diaryl and alkyl aryl ketones via palladium‐catalysed cross‐coupling reaction of arylboronic acids with acyl chlorides

“…When methanol is used as solvent, methyl benzoate is obtained in significant amounts. A lower yield of benzophenone is produced in aqueous solvents and water due to the partial hydrolysis of benzoyl chloride and formation of significant amounts of benzylic anhydride and benzoic acid as by‐products . Moderate yields are afforded using the bases Cs 2 CO 3 , Na 2 CO 3 , NaHCO 3 , K 3 PO 4 and t ‐BuOK.…”

“…A lower yield of benzophenone is produced in aqueous solvents and water due to the partial hydrolysis of benzoyl chloride and formation of significant amounts of benzylic anhydride and benzoic acid as by-products. [46] Moderate yields are afforded using the bases Cs 2 CO 3 , Na 2 CO 3 , NaHCO 3 , K 3 PO 4 and t-BuOK. No desired product is observed when Et 3 N is used in this coupling reaction.…”

Polystyrene‐supported Pd(II)–N‐heterocyclic carbene complex as a heterogeneous and recyclable precatalyst for cross‐coupling of acyl chlorides with arylboronic acids

“…Although significant developments have been achieved in this field, there are only a few reports of heterogeneous palladium complexes being employed as catalysts for the acylation reaction of boronic acids. For example, Pd/C catalytic system, silica‐supported phosphine palladium(0) complex and palladium catalyst anchored to SiO 2 functionalized with Si(CH 2 ) 3 NHCH 2 SMe have been applied to the phenylation of acyl chlorides. However, disadvantages including long reaction times, moderate yields and formation of homocoupling adducts have limited the application of these strategies.…”