1389313-51-2

Upstream product

• 288-32-4 1H-imidazole 
• 16932-44-8 2-iodo-1,3-dimethoxybenzene 
• 23112-96-1 (2,6-dimethoxyphenyl)boronic acid 

Downstream Products

• 1449509-05-0 1-benzyl-3-(2,6-dimethoxyphenyl)imidazolium bromide 

Relevant academic research and scientific papers

Chan-Lam cross-coupling reaction based on the Cu2S/TMEDA system

A catalyst based on the readily available Cu2S/TMEDA system using a stable copper(I) source was developed for the Chan-Lam cross-coupling reaction. The capability of the catalyst was demonstrated with 1H-benzo[d]imidazol-2(3H)-one, 1H-benzo[d]imidazole, and 1H-imidazole together with electron-deficient, electron-rich, and sterically demanding boronic acids at room temperature in the presence of atmospheric oxygen to give the cross-coupling products in moderate to excellent yields. In addition, the coupling reaction of 1H-benzo[d]imidazole with several pinacol or neopentylglycol boronates indicated further potential of the catalyst. The reaction conditions tolerate the hydroxyl and bromo functional groups. The catalytic system also enables to synthesize the mono-N-substituted anilines from primary aliphatic amines. However, the two model compounds for the secondary and aromatic amines, piperidine and aniline, do not react. Two sterically demanding products with the restricted C–N bond rotation, synthesized by the N-arylation of 1H-benzo[d]imidazol-2(3H)-one with o-tolylboronic acid, enabled to confirm the atropisomers prepared by the Chan-Lam cross-coupling reaction. Furthermore, an example of one-pot Chan-Lam and Suzuki-Miyaura reaction has been reported.

Barbier–Negishi Coupling of Secondary Alkyl Bromides with Aryl and Alkenyl Triflates and Nonaflates

A mild and practical Barbier–Negishi coupling of secondary alkyl bromides with aryl and alkenyl triflates and nonaflates has been developed. This challenging reaction was enabled by the use of a very bulky imidazole-based phosphine ligand, which resulted in good yields as well as good chemo- and site selectivities for a broad range of substrates at room temperature and under non-aqueous conditions. This reaction was extended to primary alkyl bromides by using an analogous pyrazole-based ligand.

Air-stable palladium(0) phosphine sulfide catalysts for Ullmann-type C-N and C-O coupling reactions

This paper describes an efficient procedure for palladium(0)-catalyzed N-arylation and O-arylation of aryl halides by Ullmann-type cross coupling reaction under mild reaction conditions in a short reaction time. Two phosphine sulphide ligands and their corresponding Pd(0) complexes namely [Pd(p2S2)(dba)] and [Pd(pp3S4)(dba)], were synthesized, where p2S2 is 1,2-bis(diphenylphosphino)ethane disulfide, pp3S4 is tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide and dba is dibenzylideneacetone. Optimal reaction conditions were determined for the arylation reactions using iodobenzene and benzimidazole by varying temperature, solvent, base and catalyst loading. The cross coupling reactions were carried out taking iodobenzenes/bromobenzenes and a wide variety of substituted aryl amines/phenols/alcohols with different steric and electronic properties to afford the desired N-aryl amines/diaryl ethers/alkyl aryl ethers in good to excellent yield (70-94%).

Resorcinarene-Functionalised Imidazolium Salts as Ligand Precursors for Palladium-Catalysed Suzuki-Miyaura Cross-Couplings

Three imidazolium salts based on a rigid resorcinarene platform (1-3) were synthesised and used as catalyst precursors in the Suzuki-Miyaura cross-coupling of aryl halides with phenylboronic acid. In these pro-carbene ligands, the heterocyclic moiety has one N atom connected to a C2 atom of a resorcinolic ring, and the other is substituted by an alkyl group (R=n-propyl, iso-propyl, benzyl). The methinic C atoms of the macrocyclic core are all substituted by a pentyl group. The best catalytic performances were obtained by using an imidazolium/Pd ratio of 1:1. The catalytic systems displayed high activities, which increased in the order R=n-propyl(1)-1h-1 in the arylation of bromotoluene at 100°C in dioxane. Comparative studies showed that the performance of imidazolium salt 3 is significantly superior to that of related salts devoid of a cavity-shaped substituent. These experiments illustrate the role of the bulky resorcinarene unit, which facilitates the reductive elimination step. Modification of the cavitand structure by replacement of the pentyl substituents with phenyl groups further revealed that the catalytic outcome is influenced by the nature of the lower belt-substituents. The results strongly suggest that the Pd catalysts obtained from 1-3 have the metal centre preferentially located outside the cavity.