Ferrocence-based phosphine-triazine ligands for highly efficient Suzuki-Miyaura cross-coupling reaction of aryl chlorides

A series of ferrocene-based phosphine-triazine ligands were successfully employed in the Pd-catalyzed Suzuki-Miyaura cross-coupling reaction of aryl chlorides with arylboronic acids, with ligand 1b was demonstrated to be the most effective one. Under optimized reaction conditions, the catalytic system displayed a remarkable tolerance towards electron-donating substituents and electron-withdrawing substituents.     

Biphenylene-substituted ruthenocenylphosphine for Suzuki-Miyaura coupling of aryl chlorides

High activity in the palladium-catalyzed Suzuki-Miyaura reactions of aryl chlorides with arylboronic acids was furnished using biphenylene-substituted di- tert-butylruthenocenylphosphine (R-Phos) as a supporting ligand. Substrate combinations even for the construction of highly hindered tetra- ortho-substituted biaryls can be achieved in good to excellent yields with low catalyst loadings in short reaction times.     

A new family of tunable indolylphosphine ligands by one-pot assembly and their applications in Suzuki-Miyaura coupling of aryl chlorides

This study describes a new class of indolylphosphine ligands, which can be easily accessed by a simple one-pot assembly from commercially available indoles, acid chlorides, and chlorophosphines. A combination of these three starting materials provides a high diversification of the ligand structure. The application of this ligand array in palladium-catalyzed Suzuki-Miyaura coupling reaction of aryl chlorides with arylboronic acids is described. A catalyst loading down to 0.01 mol % of Pd can be achieved.     

Ferrocenyl monophosphine ligands: synthesis and applications in the Suzuki-Miyaura coupling of aryl chlorides

Ferrocenyl monophosphine ligands have been developed by a method based on palladium-catalyzed Suzuki-Miyaura coupling. The modular procedure creates a rapid synthesis of phosphines with diverse properties. The electron-rich phosphines have been successfully applied to the Suzuki-Miyaura coupling of activated and deactivated aryl chlorides, with low catalyst loading being feasible in the synthesis of tris-ortho-substituted biaryls.     

A functionalized phosphine ligand with a pentaarylbenzene moiety in palladium-catalyzed Suzuki-Miyaura coupling of aryl chlorides

A functionalized phosphine with a pentaarylbenzene moiety was found to facilitate the palladium-catalyzed Suzuki-Miyaura coupling of aryl chlorides. The new ligand achieved high turnover numbers (up to TON 5000).     

Triazole-based monophosphines for Suzuki-Miyaura coupling and amination reactions of aryl chlorides

[reaction: see text] A new class of triazole-based monophosphine 1 (ClickPhos) has been prepared via efficient 1,3-dipolar cycloadditions of readily available azides and acetylenes. Palladium complexes derived from these ligands provide highly active catalysts for Suzuki-Miyaura coupling and amination reactions of aryl chlorides.     

Efficient catalyst for the Suzuki-Miyaura coupling of potassium aryl trifluoroborates with aryl chlorides

Palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of aryl- and heteroaryl chlorides with potassium aryl- and heteroaryltrifluoroborates have been accomplished with the supporting ligand S-Phos in good to excellent yield. Hindered biaryls and substrates containing a variety of functional groups can be prepared. Suzuki-Miyaura couplings of a 3-pyridyl boron-based nucleophile with aryl- and heteroaryl chlorides proceed in good to very good yield. [reaction: see text]     

P,N-Type benzimidazolyl phosphine ligands for the palladium-catalyzed Suzuki coupling of potassium aryltrifluoroborates and aryl chlorides

This study describes the efficacy of P,N-type benzimidazolyl phosphine ligands, which can be easily synthesized from commercially available and inexpensive starting materials. The application of this ligand array in palladium-catalyzed Suzuki-Miyaura coupling reaction of aryl chlorides with potassium aryltrifluoroborates is described. The air stable benzimidazolyl phosphines in combination with a palladium metal precursor provides highly effective catalysts for the Suzuki-Miyaura coupling of unactivated aryl chlorides and can achieve a catalyst loading of only 0.05 mol %.     

Efficient palladium-catalyzed Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids using benzoferrocenyl phosphines as supporting ligands

Four monodentate benzoferrocenyl phosphines were studied as supporting ligands in palladium-catalyzed Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids. Of these ligands, the more electron-rich and steric demanding benzoferrocenyl dicyclohexyl phosphine was found highly effective for the reaction followed by the benzoferrocenyl diisopropyl phosphine. The corresponding diethyl and diphenyl phosphines are much less active. When the dicyclohexyl phosphine was used, both electron-rich and electron-poor aryl chlorides were coupled with arylboronic acids within 1 h giving good to excellent yields. Chloro-substituted pyridines were also found highly reactive under these conditions giving excellent yields of biaryl products. Sterically hindered biaryls can also be prepared using the dicyclohexyl phosphine as ligand.     

Design and synthesis of thioether-imidazolium chlorides as efficient ligands for palladium-catalyzed Suzuki-Miyaura coupling of aryl bromides with arylboronic acids

The catalyst composed of 0.25-0.025 mol % of [Pd(allyl)Cl]₂ and 0.5-0.05 mol % of the thioether-imidazolium chloride 3c was proven to be efficient in the Suzuki-Miyaura cross-coupling reactions of aryl bromides with arylboronic acids.     

Suzuki-Miyaura coupling of aryl tosylates catalyzed by an array of indolyl phosphine-palladium catalysts

A family of indolyl phosphine ligands was applied to Suzuki-Miyaura cross-coupling of aryl tosylates. Catalyst loading can be reduced to 0.2 mol % for coupling of nonactivated aryl tosylate. A challenging example for room temperature coupling is realized. The scope of this highly active Pd/L2 system can be extended to other boron nucleophiles, including trifluoroborate salts and boronate esters. The ligand structural comparisons toward the reactivity in tosylate couplings are also described.     

Novel bulky pyrazolylphosphine ligands for the Suzuki coupling of aryl chlorides

Bulky 1-(3,5-di-tert-butyl)pyrazolyl-dicyclohexylphosphine and 1-(3,5-di-tert-butyl)pyrazolyl-di-tert-butylphosphine were prepared from the reactions of 3,5-di-tert-butylpyrazolide and corresponding chlorodialkylphosphines. They were successfully employed as ligands in the Suzuki coupling reactions of phenylboronic acid and various aryl bromides and chlorides.     

A bowl-shaped phosphine as a ligand in palladium-catalyzed Suzuki-Miyaura coupling of aryl chlorides: effect of the depth of the bowl

[reaction: see text] Bowl-shaped phosphine ligands were found to be highly effective in Suzuki-Miyaura coupling of unactivated aryl chlorides, in which the depth of the bowl affected the catalytic activity considerably.     

Ferrocenylmethylphosphines as ligands for room temperature Ni(0)-catalyzed Suzuki-Miyaura cross-coupling reactions of aryl arenesulfonates and aryl chlorides

Readily available ferrocenylmethylphosphine was found as an efficient ligand for room temperature Ni(0)-catalyzed Suzuki-Miyaura cross-couplings of aryl arenesulfonates. Ferrocenylmethylphosphine and its polymeric form were also found as useful ligands for Ni(0)-catalyzed Suzuki-Miyaura couplings of deactivated aryl chlorides.     

Nickel(II) complexes of bidentate N-heterocyclic carbene/phosphine ligands: efficient catalysts for Suzuki coupling of aryl chlorides

Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/phosphane ligand L were prepared and structurally characterized. Unlike palladium, which forms [PdCl(2)(L)], the stable nickel product isolated is the ionic [Ni(L)(2)]Cl(2). These Ni(II) complexes are highly robust in air. Among different N-substituents on the ligand framework, the nickel complex of ligand L bearing N-1-naphthylmethyl groups (2 a) is a highly effective catalyst for Suzuki cross-coupling between phenylboronic acid and a range of aryl halides, including unreactive aryl chlorides. The activities of 2 a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts. Unlike the previously reported [NiCl(2)(dppe)] (dppe=1,2-bis(diphenylphosphino)ethane), 2 a can effectively catalyze the cross-coupling reaction without the need for a catalytic amount of PPh(3), and this suggests that the PPh(2) functionality of hybrid NHC ligand L can partially take on the role of free PPh(3). However, for unreactive aryl chlorides at low catalyst loading, the presence of PPh(3) accelerates the reaction.     

Suzuki-Miyaura coupling reaction of aryl chlorides using di(2,6-dimethylmorpholino)phenylphosphine as ligand

Suzuki-Miyaura coupling was achieved on a variety of aryl chlorides by using di(2,6-dimethylmorpholino)phenylphosphine (L1) as a bulky electron-rich monoaryl phosphine ligand. We report the couplings of various chlorobenzenes and heteroaryl chlorides.     

Abnormal N-heterocyclic carbene palladium complex: living catalyst for activation of aryl chlorides in Suzuki-Miyaura cross coupling

Palladium complexes bearing abnormal N-heterocyclic carbene were used as catalysts in Suzuki-Miyaura cross coupling of aryl chlorides at 25 °C. The catalyst remained active for 10 successive catalytic runs and can activate 4-chlorotoluene at 25 °C with 0.01 mol% catalyst loading resulting in a TON of 9500 within 6 h.     

Practical synthesis of new and highly efficient ligands for the Suzuki reaction of aryl chlorides

A practical synthesis of a novel class of phosphine ligands, phosphino substituted N-aryl pyrroles (PAP ligands), has been developed. These ligands are applied in the palladium-catalyzed coupling of a variety of aryl and heteroaryl chlorides with phenylboronic acid showing exceedingly high turnover numbers at mild reaction temperatures and even at room temperature.     

New catalysts for Suzuki-Miyaura coupling reactions of heteroatom-substituted heteroaryl chlorides

The new air-stable PdCl2[PR2(Ph-R')]2 complexes, readily prepared from commercial reagents, exhibit unique efficiency as catalysts for the Suzuki-Miyaura coupling reactions of a variety of heteroatom-substituted heteroaryl chlorides with a diverse range of aryl/heteroaryl boronic acids. The coupling reactions catalyzed by the new complexes exhibit high product yields (88-99%) and high catalyst turnover numbers (up to 10,000 TON).