A highly active palladium(II)–bis(oxazoline) catalyst for Suzuki–Miyaura, Mizoroki–Heck and sonogashira coupling reactions in aqueous dimethylformamide

Abstract

An efficient catalytic system based on a new palladium-bis(oxazoline) (Pd-BOX-1) complex has been developed. The complex Pd-BOX-1 adopts a legless chair-type structure where the distorted square planar [PdN 2 Cl 2 ] moiety and the benzene ring spacer represent the seat and the chair back, respectively. The catalytic activity of Pd-BOX-1 has been investigated in dimethylformamide-water under aerobic and mild conditions in Suzuki-Miyaura coupling reactions of arylboronic acids with aryl iodides, aryl bromides and aryl chlorides, Mizoroki-Heck coupling reactions of aryl halides with styrene derivatives, and Sonogashira coupling reactions of aryl halides with terminal alkynes. A wide range of functional groups as substituents on the arylboronic acids and aryl halides were considered. Pd-BOX-1 demonstrates exceptional air and moisture stability. Of note, the catalyst system based on Pd-BOX-1 shows high recycling ability in Suzuki-Miyaura coupling reactions in dimethylformamide-water without any loss in catalytic activity.

Novel (N‐heterocyclic carbene)Pd(pyridine)Br2 complexes for carbonylative Sonogashira coupling reactions: Catalytic efficiency and scope for arylalkynes, alkylalkynes and dialkynes

“…We have previously reported the synthesis and catalytic activities of palladium(II) bis(oxazoline) complexes, and recently triazole‐derived NHC–palladium(II) complexes . In the present paper, we report the synthesis and crystal structures of two new mixed ligand palladium–carbene–pyridine (Pd–NHC–Py) complexes.…”

“…Recently, much attention has been paid to the development of N‐heterocyclic carbene (NHC) metal complexes, and notable advances have been made especially for their applications as organometallic catalysts . This is attributed to the ability of NHC ligands to provide highly active and stable transition metal catalysts for various organic transformations.…”

Amidophosphine‐stabilized palladium complexes catalyse Suzuki–Miyaura cross‐couplings in aqueous media

“…However, an efficient Suzuki–Miyaura protocol in aqueous media is often restricted due to limited solubility and the decreased stability of the catalyst in water . Therefore, a way to improve the efficiency of Suzuki–Miyaura catalysis in water is by the employment of hydrophilic ligands …”

PdNPs@ZIF-8 Micro-Nanostructured Catalyst of Regioselective Mizoriki-Heck Olefination

“…In addition, biphenyl (<10%) was observed to form in the case of the reaction with bromobenzene (entry #6, entry #8, entry #10, and entry #12). These obtained data were compared well with the standard catalysts (entry #12 and entry #15) . Recyclability studies were performed using the optimized conditions with styrene and iodobenzene.…”