Reactions of Methæmo-Globin and Catalase with Peroxides and Hydrogen Donors

Nature ◽  
1954 ◽  
Vol 173 (4407) ◽  
pp. 720-723 ◽  
Author(s):  
D. KEILIN ◽  
E. F. HARTREE
Keyword(s):  
Hydrogen Donors

scholarly journals Hydrogen-Free Deoxygenation of Bio-Oil Model Compounds over Sulfur-Free Polymer Supported Catalysts

2020 ◽  
Vol 7 (1) ◽  
pp. 29-36
Author(s):  
Antonina A. Stepacheva ◽  
Mariia E. Markova ◽  
Yury V. Lugovoy ◽  
Kirill V. Chalov ◽  
Mikhail G. Sulman ◽  
...  
Keyword(s):  
Supercritical Fluids ◽  
Aromatic Compounds ◽  
Supported Catalysts ◽  
Major Product ◽  
Hypercrosslinked Polystyrene ◽  
Model Compounds ◽  
Transportation Fuel ◽  
Novel Approach ◽  
Bio Oil ◽  
Hydrogen Donors

AbstractHydrotreatment of bio-oil oxygen compounds allows the final product to be effectively used as a liquid transportation fuel from biomass. Deoxygenation is considered to be one of the most promising ways for bio-oil upgrading. In the current work, we describe a novel approach for the deoxygenation of bio-oil model compounds (anisole, guaiacol) using supercritical fluids as both the solvent and hydrogen-donors. We estimated the possibility of the use of complex solvent consisting of non-polar n-hexane with low critical points (Tc = 234.5 ºC, Pc = 3.02 MPa) and propanol-2 used as H-donor. The experiments were performed without catalysts and in the presence of noble and transition metals hydrothermally deposited on the polymeric matrix of hypercrosslinked polystyrene (HPS). The experiments showed that the presence of 20 vol. % of propanol-2 in n-hexane results in the highest (up to 99%) conversion of model compounds. When the process was carried out without a catalyst, phenols were found to be a major product yielding up to 95 %. The use of Pd- and Co-containing catalyst yielded 90 % of aromatic compounds (benzene and toluene) while in the presence of Ru and Ni cyclohexane and methylcyclohexane (up to 98 %) were the main products.

2-Aryl-1,3-dimethylbenzimidazolines as Effective Electron and Hydrogen Donors in Photoinduced Electron-Transfer Reactions

2015 ◽  
Vol 68 (11) ◽  
pp. 1640 ◽  
Author(s):  
Eietsu Hasegawa ◽  
Shin-ya Takizawa
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Photoinduced Electron Transfer ◽  
Hydrogen Atom Transfer ◽  
Transfer Reactions ◽  
Organic Substrates ◽  
Iridium Complexes ◽  
Effective Electron ◽  
Hydrogen Donors ◽  
Wavelength Light

2-Aryl-1,3-dimethylbenzimidazolines (DMBIHs) have been applied to photoinduced electron-transfer reductions of various organic substrates. Either direct or indirect electron transfer between the substrates and DMBIHs is utilized to promote the desired transformations. Photoexcitation of the substrates using light above 280 nm was carried out in the former protocol whereas a photosensitization method using materials such as substituted pyrenes, ruthenium and iridium complexes that absorb longer-wavelength light was employed in the latter. In these reactions, DMBIHs undergo initial electron transfer and subsequent proton or hydrogen atom transfer.

scholarly journals Hydrogen Transfer Reactions of Carbonyls, Alkynes, and Alkenes with Noble Metals in the Presence of Alcohols/Ethers and Amines as Hydrogen Donors

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 671 ◽  
Author(s):  
Eszter Baráth
Keyword(s):  
Condensed Phase ◽  
Crucial Role ◽  
Noble Metals ◽  
Hydrogen Transfer ◽  
Transfer Reactions ◽  
Hydrogen Donors ◽  
Stereoselective Reactions ◽  
Present Summary ◽  
Industrial Relevance ◽  
Hydrogen Transfer Reactions

Hydrogen transfer reactions have exceptional importance, due to their applicability in numerous synthetic pathways, with academic as well as industrial relevance. The most important transformations are, e.g., reduction, ring-closing, stereoselective reactions, and the synthesis of heterocycles. The present review provides insights into the hydrogen transfer reactions in the condensed phase in the presence of noble metals (Rh, Ru, Pd) as catalysts. Since the H-donor molecules (such as alcohols/ethers and amines (1°, 2°, 3°)) and the acceptor molecules (alkenes (C=C), alkynes (C≡C), and carbonyl (C=O) compounds) play a crucial role from mechanistic viewpoints, the present summary points out the key mechanistic differences with the interpretation of current contributions and the corresponding historical achievements as well.

Hydrogen-Transfer-Mediated N-Arylation of Naphthols Using Indolines as Hydrogen Donors

2019 ◽  
Vol 85 (2) ◽  
pp. 508-514 ◽  
Author(s):  
Xiuwen Chen ◽  
Zhihai Yang ◽  
Xuyan Chen ◽  
Wanyi Liang ◽  
Zhongzhi Zhu ◽  
...  
Keyword(s):  
Hydrogen Transfer ◽  
Hydrogen Donors

scholarly journals Oxalic Acid as a Hydrogen Donor for the Hydrodesulfurization of Gas Oil and Deoxygenation of Rapeseed Oil Using Phonolite-Based Catalysts

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3732
Author(s):  
José Miguel Hidalgo Herrador ◽  
Jakub Fratczak ◽  
Zdeněk Tišler ◽  
Hector de Paz Carmona ◽  
Romana Velvarská
Keyword(s):  
Oxalic Acid ◽  
Rapeseed Oil ◽  
Fossil Fuels ◽  
Raw Materials ◽  
Hydrogen Donor ◽  
Gas Oil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Donors ◽  
Temperature Programmed

The use of renewable local raw materials to produce fuels is an important step toward optimal environmentally friendly energy consumption. In addition, the use of these sources together with fossil fuels paves the way to an easier transition from fossil to renewable fuels. The use of simple organic acids as hydrogen donors is another alternative way to produce fuel. The present work reports the use of oxalic acid as a hydrogen donor for the catalytic hydrodesulfurization of atmospheric gas oil and the deoxygenation of rapeseed oil at 350 °C. For this process, one commercial NiW/SiO2–Al2O3 solid and two NiW/modified phonolite catalysts were used, namely Ni (5%) W (10%)/phonolite treated with HCl, and Ni (5%) W (10%)/phonolite treated with oxalic acid. The fresh phonolite catalysts were characterized by Hg porosimetry and N2 physisorption, ammonia temperature programmed desorption (NH3-TPD), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The sulfided metal phonolite catalysts were characterized by XRD and XRF. Hydrodesulfurization led to a decrease in sulfur content from 1 to 0.5 wt% for the phonolite catalysts and to 0.8 wt% when the commercial catalyst was used. Deoxygenation led to the production of 15 and 65 wt% paraffin for phonolite and commercial solids, respectively. The results demonstrate the potential of using oxalic acid as a hydrogen donor in hydrotreating reactions.

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