75601-34-2

Usage

Chemical class

Pyridine compound

Physical state

Colorless to pale yellow liquid

Odor

Strong, sweet

Primary use

Reagent in organic synthesis

Applications

Production of pharmaceuticals, agrochemicals, specialty chemicals, coordination chemistry

Versatility

Significant applications in various industries

Upstream product

• 626-55-1 3-Bromopyridine 
• 5980-97-2 mesitylboronic acid 
• 576-83-0 2,4,6-trimethylphenyl bromide 
• 1692-25-7 3-pyridylboronic acid 
• 626-60-8 3-Chloropyridine 
• 2633-66-1 2-mesitylmagnesium bromide 

Relevant academic research and scientific papers

Mild negishi cross-coupling reactions catalyzed by acenaphthoimidazolylidene palladium complexes at low catalyst loadings

Considering that the strong σ-donor property of ylidenes derived from π-extended imidazolium salts is conducive to increasing the catalytic activity of the resulting palladium N-heterocyclic carbene complexes, robust acenaphthoimidazol-ylidene palladium complexes 3a-c with varying bulky substituted groups were prepared from the corresponding acenaphthoimidazolium chlorides by heating with PdCl2 and K2CO3 in neat 3-chloropyridine in satisfactory yields. Even at a catalyst loading as low as 0.25 mol %, complex 3a exhibited extremely high catalytic activity toward Negishi cross-coupling of alkylzinc reagents with a wide range of (hetero)aryl halides under mild reaction conditions within 30 min. Besides a great number of bromoarenes, various less expensive and inactive (hetero)aryl chlorides were coupled successfully with the alkyl- and arylzinc reagents, in which active functional groups (such as -NH2) were well tolerated even in one-pot dicoupling transformations without protection. In addition, in the case of coupling with secondary alkylzinc reagents, undesired β-hydride elimination leading to isomerized linear products was efficaciously suppressed. The catalyst system also displayed superiority in the construction of heterobiaryls through the coupling of heteroarylzinc reagents and heterocylic chloroarenes which were hardly accessible from the corresponding organoboron reagents by Suzuki-coupling reactions. Therefore, the protocol described in this paper represents a mild, general, and scalable approach to access various structurally intriguing and functionalized (hetero)aryls.

Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates

Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.

Kumada-Tamao-Corriu coupling of heteroaromatic chlorides and aryl ethers catalyzed by (IPr)Ni(allyl)Cl

The complex (IPr)Ni(allyl)Cl (IPr = 1,3-bis(2,6-diisopropylphenyl) imidazolidene) catalyzes the cross-coupling reactions of heteroaromatic chlorides with aryl Grignard reagents. Catalyst loadings as low as 0.1 mol % have been used to afford the products in excellent yields. This nickel-based catalytic system also promotes the activation of the CAr-O bond of anisoles in the Kumada-Tamao-Corriu reaction under fairly mild conditions.

A general and special catalyst for suzuki-miyaura coupling processes

(Figure Presented) Biaryl monophosphorus ligands containing a 2,3-dihydrobenzo[d][1,3]oxaphosphole framework are highly effective for the palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of a wide range of substrates. Ligand 1 has demonstrated excellent performance for coupling reactions of extremely hindered arylboronic acids.

Efficient diphosphane-based catalyst for the palladium-catalyzed suzuki cross-coupling reaction of 3-pyridylboronic acids

A highly active catalyst system derived from PdCl2 and 2,2',6,6'- tetramethoxy-4,4'-bis(diphenylphosphanyl)-3,3'-bi- pyridine (P-Phos) has been developed for the Suzuki cross- coupling reaction of pyridylboronic acid with a variety of aryl halides in good to excellent yields, even in the presence of hindered and functional groups. In addition, P-Phos also exhibited high activity in the palladium-catalyzed Suzuki reaction of 2,6-dimethoxypyridylboronic acid in excellent yields with a fast rate. The steric and electronic effects of the P- Phos-palladium complex to this cross-coupling reaction were also discussed.

Catalysts for Suzuki-Miyaura coupling processes: Scope and studies of the effect of ligand structure

Suzuki-Miyaura coupling reactions of aryl and heteroaryl halides with aryl-, heteroaryl- and vinylboronic acids proceed in very good to excellent yield with the use of 2-(2′,6′-dimethoxybiphenyl) dicyclohexylphosphine, SPhos (1). This ligand confers unprecedented activity for these processes, allowing reactions to be performed at low catalyst levels, to prepare extremely hindered biaryls and to be carried out, in general, for reactions of aryl chlorides at room temperature. Additionally, structural studies of various 1·Pd complexes are presented along with computational data that help elucidate the efficacy that 1 imparts on Suzuki-Miyaura coupling processes. Moreover, a comparison of the reactions with 1 and with 2-(2′,4′,6′-triisopropylbiphenyl)diphenylphosphine (2) is presented that is informative in determining the relative importance of ligand bulk and electron-donating ability in the high activity of catalysts derived from ligands of this type. Further, when the aryl bromide becomes too hindered, an interesting C-H bond functionalization-cross-coupling sequence intervenes to provide product in high yield.

Suzuki coupling reactions of heteroarylboronic acids with aryl halides and arylboronic acids with heteroaryl bromides using a tetraphosphine/palladium catalyst

cix,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/ [PdCl(C3H5)]2 efficiently catalyses the Suzuki reaction of heteroarylboronic acids with aryl bromides and also the coupling of arylboronic acids with heteroaryl bromides. The coupling of thiopheneboronic acids, 3-furanboronic acid and 3-pyridineboronic acid with a variety of aryl bromides gave the corresponding adducts in good yields. However, in most cases, better results in terms of substrate/catalyst ratio were obtained for the reaction of heteroaryl bromides with arylboronic acids. Georg Thieme Verlag Stuttgart.