1019-90-5

Upstream product

• 65-85-0 benzoic acid 
• 95-85-2 2-hydroxy-5-chloro-aniline 
• 41981-24-2 methyl benzenecarbimidothioate hydroiodide 
• 29644-82-4 N-benzylidene-2-hydroxy-5-chloroaniline 
• 591-50-4 iodobenzene 
• 17200-29-2 5-chloro-benzoxazole 
• 28443-50-7 2-amino-5-chlorophenol 
• 6004-21-3 3'-chloro-benzanilide 
• 100-52-7 benzaldehyde 
• 6373-47-3 2-(benzyloxy)-5-chloroaniline 
• 1679-18-1 4-Chlorophenylboronic acid 
• 3240-34-4 [bis(acetoxy)iodo]benzene 
• 89-64-5 p-chloro-o-nitrophenol 
• 100-51-6 benzyl alcohol 

Relevant academic research and scientific papers

Iron-Catalyzed Sulfur-Promoted Decyanative Redox Condensation of o-Nitrophenols and Arylacetonitriles: An Unprecedented Route to 2-Arylbenzoxazoles

Elemental sulfur in the presence of a catalytic amount of FeCl2·4H2O was found to be highly efficient for the promotion of decyanative redox condensation reactions of o-nitrophenols with arylacetonitriles, to give a wide range of 2-arylbenzoxazoles. The utility of elemental sulfur was highlighted by its role as cyanide scavenger and external reducing agent.

Oxidation of N-benzylidene-2-hydroxyaniline by dioxygen catalysed by a dicobalt complex

The oxidation of N-benzylidene-2-hydroxyaniline and its related derivatives by O2 catalysed by [Co2L(μ-OH)] {H3L = 2,6-bis[(2-hydroxyphenyl)iminomethyl]-4-methylphenol} in DMF at 363 K was investigated. The oxidation products were the corresponding 2-substituted benzoxazoles. However, a side reaction leading to 2-aminophenoxazine-3-one via hydrolysis of the starting compound with water produced in the oxidation, followed by the oxidation of aminophenol, was established. If a dehydrating agent such as anhydrous Na2SO4 or 4 A molecular sieves was present in the reaction mixture the isolated product yields were above 87%. The fact that the reaction rate of the oxidation process in the presence of a radical scavenger was similar to that without suggests that it was a non-radical process. The initial oxidation rates depended linearly on the concentration of catalyst. The rates also depended linearly on the concentration of the organic substrate N-benzylidene-2-hydroxyaniline and O2 pressure when these variables were small ([substrate] 2 pressure 2 pressure the rate showed saturation behavior. These kinetic data could be satisfactorily accounted for by a mechanism with initial co-ordination of substrate to [Co2L(μ-OH)], followed by the co-ordination of O2 to the catalyst, then the rate limiting step of oxidation of substrate. The formation of the adduct between N-benzylidene-2-hydroxyaniline and catalyst at 298 K was characterized by UV-Vis spectroscopy. The variation of the initial rates among the organic substrates could be explained by stereoelectronic effects. Moreover, the influence of acetic acid which slowed the initial rate of oxidation and weak base (2,6-di-tert-butylpyridine) which had little effect on the rate could also be satisfactorily accounted for based on the acid-base properties of the proposed reaction intermediates.

Mechanistic exploration of the palladium-catalyzed process for the synthesis of benzoxazoles and benzothiazoles

A convenient one-pot palladium-catalyzed cascade process for the preparation of both benzoxazoles and benzothiazoles has been developed. While these reactions proceed to give similar compounds the mechanisms governing the processes are different as are the experimental conditions employed.

Sulfur/DABCO Promoted Reductive Coupling/Annulation Cascade Reaction between o -Hydroxy/Amino Nitrobenzenes and Benzaldehydes

Sulfur/DABCO was found to be an efficient reagent in promoting- the reductive coupling/annulation of o -nitrophenols or o -nitroanilines with benzaldehydes. This method represents a simple, straightforward, and green approach to the construction of benz-oxazoles and benzimidazoles.

Iron-catalyzed 2-arylbenzoxazole formation from o-nitrophenols and benzylic alcohols

The iron-catalyzed 2-arylbenzoxazole formation from o-nitrophenols and benzylic alcohols using hydrogen transfer is described. Various 2-arylbenzoxazoles were selectively obtained in good to excellent yields. The reaction tolerated a wide range of functionalities. The alcohol oxidation, nitro reduction, condensation, and dehydrogenation were realized in a cascade without external reducing reagent and oxidant.

Gold nanoparticles supported on titanium dioxide: An efficient catalyst for highly selective synthesis of benzoxazoles and benzimidazoles

A highly efficient and selective reaction for the synthesis of 2-substituted benzoxazoles and benzimidazoles catalyzed by Au/TiO2 has been developed via two hydrogen-transfer processes. This reaction has a good tolerance to air and water, a wide substrate scope, and represents a new avenue for practical C-N and C-O bond formation. More importantly, no additional additives, oxidants and reductants are required for the reaction and the catalyst can be recovered and reused readily. This journal is the Partner Organisations 2014.

Mechanistic evidence for a ring-opening pathway in the Pd-catalyzed direct arylation of benzoxazoles

The direct Pd-catalyzed arylation of 5-substituted benzoxazoles, used as a mechanistic model for 1,3-azoles, was investigated experimentally and computationally. The results of the primary deuterium kinetic isotope effect, Hammett studies, and H/D exchange were shown to be inconsistent with the rate-limiting electrophilic or concerted palladation. A mechanism, proposed on the basis of kinetic and computational studies, includes generation of isocyanophenolate as the key step. The DFT calculations suggest that the overall catalytic cycle is facile and is largely controlled by the C-H acidity of the substrate. Copyright

Tin(II) chloride-mediated synthesis of 2-substituted benzoxazoles

2-Aminophenols react with an array of carboxylic acids in dioxane at 180° in the presence of tin(II) chloride to afford the corresponding 2-substituted benzoxazoles in good yields. The reaction is applicable to a wide range of alkyl, alkenyl, aryl carboxylic acids.

Cyanide as a powerful catalyst for facile preparation of 2-substituted benzoxazoles via aerobic oxidation

A cyanide-catalyzed synthesis of 2-substituted benzoxazoles from Schiff bases via aerobic oxidation has been developed. The products from various Schiff bases were obtained in high yields in an open flask under ambient conditions without other external oxidants. We have also developed a simple one-step protocol for the synthesis of benzoxazoles from aminophenol and the corresponding aldehydes in the presence of cyanide without isolation of imine intermediates. Copyright

Synthesis of 2-Arylbenzoxazoles via the Palladium-Catalyzed Carbonylation and Condensation of Aromatic Halides and o-Aminophenols

A new synthetic method is reported in which 2-arylbenzoxazoles can be prepared by palladium-catalyzed condensation of aryl halides with o-aminophenols followed by dehydrative cyclization.This method is tolerant of a wide variety of functional groups on either aromatic ring and gives good to excellent yields of products.An aliphatic vicinal amino alcohol gave a bis-acylated product as well as a chlorine-containing product with only a small amount of the desired 2-aryloxazole being formed.Methyl iodide and benzyl bromide gave only alkylated products.