2562-78-9

Upstream product

• 2751-84-0 2-(4-bromophenyl)-1-methyl-1H-benzo[d]imidazole 
• 98-80-6 phenylboronic acid 
• 4760-34-3 N-methyl-1,2-phenylenediamine 
• 1632-83-3 1-Methylbenzimidazole 
• 613-37-6 4-methoxylbiphenyl 
• 701-56-4 4-methoxy-N,N-dimethylanilne 

Relevant academic research and scientific papers

Solid-phase synthesis of benzazoles, quinazolines, and quinazolinones using an alkoxyamine linker

An alkoxyamine linker was applied for the solid-phase synthesis of benzazoles, quinazolines, and quinazolinones. Aromatic aldehydes were anchored by aldoxime linkage. After some reactions on a solid support, the products were cleaved with paraformaldehyde under the acidic conditions to afford the corresponding aldehydes, which were subsequently subjected to oxidative coupling with 2-substituted anilines under air atmosphere to give the desired compounds.

Nickel-Catalyzed Heteroarenes Cross Coupling via Tandem C-H/C-O Activation

Inert aryl methyl ethers as coupling components via C-O activation have been established with a Ni catalyst for C-H activation of heteroarene. The key to simultaneous C-H/C-O bond activation is the use of sterically demanding o-tolylMgBr. The protocol is effective for a wide scope of substrates including naphthyl methyl ethers, anisoles, and a variety of other heteroarene derivatives. Detailed mechanistic studies indicated that the C-O cleavage is assisted via synergistic effect of nickel and Grignard reagent in this C-H/C-O reaction, which is supported by DFT calculation. At this stage, single-electron transfer can be ruled out as a main operative process for this tandem strategy.

C-H arylation and alkenylation of imidazoles by nickel catalysis: Solvent-accelerated imidazole C-H activation

The first nickel-catalyzed C-H arylations and alkenylations of imidazoles with phenol and enol derivatives are described. Under the influence of Ni(OTf)2/dcype/K3PO4 (dcype: 1,2-bis(dicyclohexylphosphino)ethane) in t-amyl alcohol, imidazoles can undergo C-H arylation with phenol derivatives. The C-H arylation of imidazoles with chloroarenes as well as that of thiazoles and oxazoles with phenol derivatives can also be achieved with this catalytic system. By changing the ligand to dcypt (3,4-bis(dicyclohexylphosphino)thiophene), enol derivatives could also be employed as coupling partners achieving the C-H alkenylation of imidazoles as well as thiazoles and oxazoles. Thus, a range of C2-arylated and alkenylated azoles can be synthesized using this newly developed nickel-based catalytic system. The key to the success of the C-H coupling of imidazoles is the use of a tertiary alcohol as solvent. This also allows the use of an air-stable nickel(ii) salt as the catalyst precursor.

Synthesis of 1-methylbenzimidazoles from carbonitriles

The NaH-mediated N-methylbenzimidazole formation starting from carbonitriles and N-methyl-1,2-phenylenediamine is reported to be a procedure compatible with acid-labile acetal protective groups within the starting materials. Products were further converte

Ligand coupling and neighbouring-group effects in the alkaline hydrolysis of arylphosphonium salts: new stable tetraarylphosphonium benzimidazolate betaines

The reactions with aqueous alkali of a series of 2-(o- and p-triphenylphosphoniophenyl)-benzimidazoles and -benzothiazoles have been investigated.Evidence of a neighbouring-group hypervalent interaction between the pyridine-like nitrogen of the benzazole and the 2-(o-triphenylphosphoniophenyl) substituent is presented from the results of a study of the course of alkaline hydrolysis of the salts and a comparison with that of the related 2-(p-triphenylphosphoniophenyl) systems in which such hypervalent interactions are not possible.Hydrolysis of the latter proceeds abnormally, in some cases, with formation of biaryl coupling products in addition to the expected hydrolysis products.Similar results have been obtained from a comparison of the products of hydrolysis of o- and p-(benzoylphenyl)triphenylphosphonium salts, hydrolysis of the latter also giving rise to a biaryl coupling product, 4-benzoylbiphenyl.Traces of 4-cyanobiphenyl were also detected in the products of hydrolysis of p-cyanophenyl(triphenyl)phosphonium bromide.The kinetics of hydrolysis of the above range of salts has been investigated in an ethanol-water solvent system (80:20 v/v).Whereas the benzoylphenylphosphonium salts undergo hydrolysis according to the usual third-order rate law, both series of salts derived from 1-methyl-2-phenylbenzimidazole and 2-phenylbenzothiazole are hydrolysed according to a second-order rate law, perhaps attributable to the interaction of the azole nitrogen with the solvent.Treatment of both 2-(o- and p-triphenylphosphoniophenyl)benzimidazoles with 1 equivalent of aqueous alkali results in the formation of the related tetraarylphosphonium benzimidazolate betaines.The ortho-isomer exhibits a marked shielding of the 31P nucleus (δp - 14.7) compared with the para-isomer (δp 22.6), consistent with a hypervalent interaction of the phosphonium centre with the benzimidazolate moiety.

LIGAND-COUPLING IN THE ALKALINE HYDROLYSIS OF ARYLPHOSPHONIUM SALTS

Biaryls are formed via a ligand-coupling process in the alkaline hydrolysis of a series of tetraarylphosphonium salts which bear electron-withdrawing substituents in the para position of one of the aryl rings.Key words: Biaryls; tetraarylphosphonium salt hydrolysis; hypervalent intermediates.