77972-48-6Relevant articles and documents
Pd-Au-Y as Efficient Catalyst for C-C Coupling Reactions, Benzylic C-H Bond Activation, and Oxidation of Ethanol for Synthesis of Cinnamaldehydes
Sharma, Mukesh,Das, Biraj,Baruah, Manash J.,Biswas, Subir,Roy, Subhasish,Hazarika, Anil,Bhargava, Suresh K.,Bania, Kusum K.
, p. 5860 - 5875 (2019)
Pd-Au nanoalloy supported on zeolite-Y (Pd-Au-Y) matrix was found to be an effective catalyst for C-Cl bond activation and oxidative coupling of 2-naphthol, leading to the formation of various biaryl products and 1,1′-bi-2-naphthol, BINOL. The same catalyst was also highly efficient for selective oxidation of benzylic alcohols to benzaldehydes. Cinnamaldehydes were obtained directly from benzaldehydes by aldol condensation with acetaldehyde generated in situ by partial oxidation of ethanol in the presence of Pd-Au-Y catalyst at 120 °C under basic condition. The biaryl products were also obtained directly from benzylic alcohols in a one-pot system by reacting with phenylboronic acid. The formation of biaryls from benzylic alcohols was believed to occur via one-pot benzylic C-H and C-Cl bond activation. A high % yield of biaryls, BINOL, aldehydes, and cinnamaldehydes was obtained by performing different reactions using the single Pd-Au-Y catalyst. The strong interaction of chloro-benzylic alcohol was predominantly located at active gold species. X-ray photoelectron and diffuse reflectance spectroscopic studies revealed the strong interaction between Pd and Au particles. Electrochemical studies provided proper evidence for the individual role of the nanoparticles (NPs) in one-pot synthesis of biaryls from benzylic alcohols.
Boosting multiple photo-assisted and temperature controlled reactions with a single redox-switchable catalyst: Solvents as internal substrates and reducing agent
Bania, Kusum K.,Baruah, Manash J.,Bhattacharyya, Pradip K.,Das, Biraj,Karunakar, Galla V.,Roy, Subhasish,Saikia, Lakshi,Saikia, Pinku,Sharma, Mukesh
, p. 104 - 121 (2020/06/01)
An alternative and economically viable process for the synthesis of β-aryl enals, enones and the aryl amines has been developed by partial oxidation of ethanol, isopropanol and N, N-dimethyl formamide (DMF). The formation of β-aryl enals, enones and the aryl amines was catalyzed by a mixed metal oxides layer of cobalt and chromium supported on halloysite nanotubes, designated as CoCr2O4-HNT. The C[sbnd]C and C[sbnd]N bond formation reactions were found to be influenced by temperature and the nature of base. The condensation of aldehyde with in situ generated acetaldehyde by ethanol oxidation forming β-aryl enals occurred selectively at 120 °C. The partial oxidation of isopropanol to acetone and its condensation with aldehydes forming β-aryl enones occurred at room temperature. Increase in temperature caused the liberation of hydrogen gas from isopropanol and allowed the reversible reduction of aldehydes to alcohols. Increase in temperature in isopropanol and increase in base concentration in ethanol causes the selective reduction of aldehydes to alcohols. Besides being active for the Claisen-Schmidt type of reactions and the aryl halides amination process, the synthesized catalyst was also found to be highly active for the photocatalytic oxidation of benzyl alcohols in absence of any external oxidizing agent. The positive holes (h+) generated at the Co(II) site as evident from EPR analysis was considered to be responsible for high photocatalytic activity of the material reducing the recombination rate of holes and electrons (e?). Density Functional Theory calculations were performed to understand the mechanism of ethanol oxidation to acetaldehyde.
Reactions of Vinylphosphonates. 2. Synthesis of Functionalized Dienes, Trienes, and Their Analogues. Synthetic Aplications to Regioselectively Functionalized Benzene Derivatives
Minami, Toru,Nishimura, Katsuhide,Hirao, Ichiro,Suganuma, Hiroyuki,Agawa, Toshio
, p. 2360 - 2363 (2007/10/02)
The phosphoryl-stabilized carboanions prepared from vinylphosphonates 1a,b and various carbanions 2a-c react with aldehydes 3 to give olefins having various functional groups.The dienes 5c-g produced by the reaction using α,β-unsaturated aldehydes and a methyl (methylsulfinyl)methyl sulfide carbanion (2b) easily undergo thermolysis to afford reactive intermediate 1-methylthio 1,3,5-trienes, which are converted into the 1,4-disubstituted benzenes 7a-e in 27-56percent overall isolated yields via the electrocyclic reaction into cyclohexadienes and subsequent elimination of methanethiol.Thermolysis of the reaction product using ethyl α-(diethylphosphono)acrylate (1a), 2b, and 1,4-bis(2-formylethenyl)benzene (3g) produces 4,4''-bis(ethoxycarbonyl)-1,1':4',1''-terphenyl (7f) in 16percent yield.The reaction using an ethyl (methylthio)acetate carbanion (2c) instead of 2b gives thermally stable dienes 5i-l in 38-52percent yields.Oxidation of the dienes 5i,k,l followed by thermolysis, leads to the 1,2,4-trisubstituted (8a,b) and 1,2-disubstituted benzenes (9).Similar treatment of the product 5m derived from 1a, 2c, and 3-phenylpropargylaldehyde (3f) produces a mixture of 2,4-bis(ethoxycarbonyl)biphenyl (8a) and ethyl 4-(ethoxycarbonyl)-7-phenylhepta-2,4-dien-6-ynoate (11) in 23percent and 32percent yields.
