Guanidine/Pd(OAc)₂-Catalyzed Room Temperature Suzuki Cross-Coupling Reaction in Aqueous Media under Aerobic Conditions

Abstract

A highly efficient Pd(OAc)2/guanidine aqueous system for the room temperature Suzuki cross-coupling reaction has been developed. The new water-soluble and air-stable catalyst Pd(OAc)2.(1f)2 from Pd(OAc)2 and 1,1,3,3-tetramethyl-2-n-butylguanidine (1f) was synthesized and characterized by X-ray crystallography. In the presence of Pd(OAc)2.(1f)2, coupling of arylboronic acids with a wide range of aryl halides, including aryl iodides, aryl bromides, even activated aryl chlorides, was carried out smoothly in aqueous solvent to afford the cross-coupling products in good to excellent yields and high turnover numbers (TONs) (TONs up to 850,000 for the reaction of 1-iodo-4-nitrobenzene and phenylboronic acid). Furthermore, this mild protocol could tolerate a broad range of functional groups.

Polymer precursors from catalytic reactions of natural oils

“…A very original approach from Zhang and co-workers on developing a guanidine-derived ligand was carried out. 253 The catalyst is then soluble in water, but permits also the Suzuki-Miyaura coupling of aryle chlorides at very low catalyst loading at ambient temperature.…”

Synthesis, Coordination Chemistry and Bonding of Strong N‐Donor Ligands Incorporating the 1H‐Pyridin‐(2E)‐Ylidene (PYE) Motif

“…[41][42][43][44][45][46] For PYE-type compounds, conjugation between the pyridine and imine moieties suggests that, as ligands, these compounds could exhibit strong donation owing to a contribution of the pyridinium-amido resonance structure to the metal-ligand bond (B in Scheme 1). In this regard, a recent report by Johnson describes the selective nickel-mediated C À F activation of aryl fluorides by using isopropyl(1-methyl-1H-pyridin-4-ylidene)amine (Scheme 2) and direct comparison is made with strong donors such as N-heterocyclic carbenes (NHCs).…”

The Suzuki–Miyaura Cross-Coupling as a Versatile Tool for Peptide Diversification and Cyclization

“…For example, 3,3′,3″-phosphanetriyltris(benzene sulfonic acid) trisodium salt (TPPTS 77a, Figure 12) [18,64], its xylene analogue TXPTS 77b [64,133], sodium 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl-3'-sulfonate (SSPhos 78) [10,96], and water-soluble NHC-ligands (N-heterocyclic carbene), such as 79 [134][135][136][137], have been proposed for Pd-catalysis in aqueous media (Figure 12). Suzuki-Miyaura reactions encompassing other water soluble ligands [11,12,138], or additives such as polyethyleneglycol and surfactants were also applied [11,34,139] Notably for Suzuki-Miyaura reaction in aqueous conditions, ligands containing the guanidine functionality, such as 2-aminopyrimidine-4,6-diol disodium salt (ADHP 80a) [63,140], its dimethylated analogue (N,N-diMeADHP 80b) [34], and (methyl)guanidines 81 and 82 [34,141,142], have been reported. The development of peptide diversification through Suzuki-Miyaura reactions in a purely aqueous environment was first reported by Vilaró et al [143].…”