- Reductive Deamination with Hydrosilanes Catalyzed by B(C6F5)3
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The strong boron Lewis acid tris(pentafluorophenyl)borane B(C6F5)3 is known to catalyze the dehydrogenative coupling of certain amines and hydrosilanes at elevated temperatures. At higher temperature, the dehydrogenation pathway competes with cleavage of the C?N bond and defunctionalization is obtained. This can be turned into a useful methodology for the transition-metal-free reductive deamination of a broad range of amines as well as heterocumulenes such as an isocyanate and an isothiocyanate.
- Fang, Huaquan,Oestreich, Martin
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supporting information
p. 11394 - 11398
(2020/05/25)
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- A practical and general ipso iodination of arylboronic acids using N-iodomorpholinium iodide (NIMI) as a novel iodinating agent: mild and regioselective synthesis of aryliodides
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A mild and efficient protocol for the ipso-iodination of aryl boronic acids using N-iodomorpholinium iodide (NIMI) generated in situ from morpholine and molecular iodine as a novel iodinating agent has been developed. The addition of a catalytic amount of copper iodide found to promote rate enhancement of the iodination reaction and dramatic increase in the yield depending upon the nature of the boronic acid was observed. The mechanistic study revealed that depending upon the nature of the substrate, either the classical ipso substitution or copper catalysed iododeborylation pathway overall dominates the present iodination reaction. The features such as mild reaction conditions, operational simplicity, high to excellent yields, excellent functional group compatibility and low catalyst loading make this method potentially useful in organic synthesis.
- Tale,Toradmal,Gopula
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p. 84910 - 84919
(2015/10/28)
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- Efficient and direct iodination of alkyl benzenes using polymer/HIO4 and I2 under mild condition
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An efficient and rapid method has been found for the iodination of aromatic compounds using iodine and polymer-supported periodic acid (PSPIA) as an oxidant under mild aprotic conditions. The reagent after the completion of the reaction was easily removed by filtration and was regenerated for further use. This method has some advantages such as: mild reaction conditions, straight forward procedure, inexpensive method, high yields and one-pot conversion.
- Bahrami-Nasab, Sepideh,Nazifi, S. Mohamad Reza,Pourali, Ali Reza
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p. 305 - 308
(2014/06/24)
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- InBr3-catalyzed reduction of ketones with a hydrosilane: Deoxygenation of aromatic ketones and selective synthesis of secondary alcohols and symmetrical ethers from aliphatic ketones
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An InBr3-Et3SiH reducing system was developed to selectively convert aliphatic ketones to a variety of secondary alcohols in moderate to good yields. An initial mixing of InBr3 and PhSiH 3 was followed by the addition of aliphatic ketones and a solvent to afford the symmetrical ether derivatives.
- Sakai, Norio,Nagasawa, Ken,Ikeda, Reiko,Nakaike, Yumi,Konakahara, Takeo
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experimental part
p. 3133 - 3136
(2011/06/26)
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- Desulfonyloxyiodination of arenesulfonic acids with mCPBA and molecular iodine
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Treatment of p-alkylbenzenesulfonic acids with mCPBA and molecular iodine gave p-alkyliodobenzenes in good to moderate yields via electrophilic ipso-substitution by the iodonium species (I+) formed. This desulfonyloxyiodination was promoted by the addition of a catalytic amount of iodoarenes, such as o-iodobenzoic acid. The same treatment of dimethylbenzenesulfonic acids and trimethylbenzenesulfonic acids with mCPBA and molecular iodine proceeded smoothly both in the absence and in the presence of o-iodobenzoic acid to provide the corresponding monoiodo-dimethylbenzene and diiodo-dimethylbenzene, and diiodo-trimethylbenzene and triiodo- trimethylbenzene, in good to moderate yields, respectively. On the other hand, the same desulfonyloxyiodination of benzenesulfonic acid and p-chlorobenzenesulfonic acid with mCPBA and molecular iodine proceeded only in the presence of o-iodobenzoic acid to generate iodobenzene and p-chloroiodobenzene, respectively, in moderate yields.
- Suzuki, Yuhsuke,Ishiwata, Yoshihide,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 5950 - 5953
(2010/11/21)
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- Synthesis of oxygen- and sulfur-bridged dirhodium complexes and their use as catalysts in the chemoselective hydrogenation of alkenes
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Oxygen-bridged and sulfur-bridged rhodium homobimetallic complexes were synthesized as air-stable crystals by using 2,6-bis(phosphanylmethyl)phenolate and -thiophenolate as the ligands, respectively. The oxygen-bridged dirhodium complex has a symmetrical structure where the carbon atom at the ipso position, oxygen, and two rhodium atoms are located in the same plane. It is thermally stable compared to the sulfur-bridged dirhodium complex and shows catalytic activity for hydrogenation of alkenes with high chemoselectivity.
- Zhu, Chuan,Yukimura, Noriaki,Yamane, Motoki
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experimental part
p. 2098 - 2103
(2010/06/19)
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- METHOD OF PRODUCING IODIZING AGENT, AND METHOD OF PRODUCING AROMATIC IODINE COMPOUND
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A method of the present invention, for producing an iodizing agent, includes the step of electrolyzing iodine molecules in a solution by using an acid as a supporting electrolyte. This realizes (i) a method of producing an iodine cation suitable for use as an iodizing agent that does not require a sophisticated separation operation after iodizing reaction is completed, and (ii) an electrolyte used in the method. Further, a method of the present invention, for producing an aromatic iodine compound, includes the step of causing an iodizing agent, and an aromatic compound whose nucleus has one or more substituent groups and two or more hydrogen atoms, to react with each other under the presence of a certain ether compound. This realizes such a method of producing an aromatic iodine compound that position selectivity in iodizing reaction of an aromatic compound is improved.
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Page/Page column 9
(2010/05/13)
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- Practical electrochemical iodination of aromatic compounds
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A practical method for electrochemical iodination of aromatic compounds was developed. The method involves the generation of I+ by electrochemical oxidation of I2 in CH3CN using H 2SO4 as supporting electrolyte followed by the reaction with aromatic compounds. The para/ortho selectivity for the reaction of mono-substituted benzenes was significantly improved using dimethoxyethane as cosolvent in the second step. The reaction with highly reactive aromatic compounds led to the formation of significant amounts of diiodo compounds in a macrobatch reactor. This problem was solved by fast 1:1 mixing of I+ with an aromatic compound using a microflow system consisting of a T-shaped micromixer and a microtube reactor.
- Kataoka, Kazuhide,Hagiwara, Yuji,Midorikawa, Koji,Suga, Seiji,Yoshida, Jun-Ichi
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p. 1130 - 1136
(2013/01/03)
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- Synthesis, Solubility, and Reaction of Long Alkyl-Chained Hypervalent Iodine Benzyne Precursors
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Long-chained hypervalent iodine benzyne precursors bearing ethyl, butyl, hexyl, octyl, decyl, dodecyl, and tetradecyl groups were synthesized, respectively. As the alkyl chain of the benzyne precursors is lengthened, the solubility in nonpolar organic solvents and the yield of the benzyne adduct with furan gradually increases.
- Abe, Takayoshi,Yamaji, Teizo,Kitamura, Tsugio
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p. 2175 - 2178
(2007/10/03)
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- Zinc(II) promoted conversion of aryltriazenes to aryl iodides and aryl nitriles
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Aryltriazenes react with zinc perchlorate/zinc cyanide to produces arylnitriles and react with zinc iodide to produce aryliodides. The reaction mechanism involves aryl radicals that have been trapped by addition to propenenitriles in a good preparative Meerwein arylation process.
- Patrick, Timothy B.,Juehne, Thomas,Reeb, Elmer,Hennessy, Daniel
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p. 3553 - 3554
(2007/10/03)
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- Iodination of aromatic compounds with iodine monochloride in aqueous sulfuric acid
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Iodine monochloride in aqueous sulfuric acid turned out to be a convenient and general reagent for preparative iodination of alkylbenzenes, phenol ethers, and aromatic amines. The relative selectivity and activity of iodine monochloride in aqueous solutions of sulfuric acid with various concentrations were determined using toluene as model substrate. Raising the sulfuric acid concentration results in considerable increase of the electrophilicity of ICl. Effective sulfuric acid concentrations were determined for specific substrate series. Iodine monochloride in aqueous sulfuric acid shows enhanced selectivity in the synthesis of monoiodo derivatives.
- Chaikovskii,Filimonov,Kharlova,Chernova,Sharapova
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p. 666 - 670
(2007/10/03)
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- POTASSIUM PERMANGANATE - A CONVENIENT OXIDANT FOR DIRECT IODINATION OF AROMATIC COMPOUNDS.
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The authors propose the use of potassium permanganate for direct iodination of aromatic compounds. They tested an iodination system containing iodine, potassium permanganate, and sulfuric and nitric acids on a large number of aromatic compounds. Experimental results show that it is effective for iodination of benzene, halobenzenes, oxygen-containing arenes, alkylbenzenes, and certain condensed hydrocarbons. Iodide yields are often close to, or even higher than, those obtained with the use of periodic and iodic acids. Potassium permanganate has not been used previously for iodination of aromatic compounds, probably because in absence of additives its activating effect on iodine is very weak. However, the effectiveness of the reaction is raised sharply when sulfuric acid is added to the system. This is due both to the higher degree of ionization of iodine molecules, as the result of which the electrons of the I-I bond become more accessible to the oxidant, and to the higher oxidizing power of potassium permanganate in a strongly acidic medium.
- Chaikovskii,Novikov
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p. 121 - 123
(2007/10/02)
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- SELECTIVE REDUCTION WITH LITHIUM ALUMIMIUM HYDRIDE/DIPHOSPHORUS TETRAIODIDE. A MILD CONVERSION OF AROMATIC KETONES TO PARENT HYDROCARBONS
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Treatment of aromatic ketones with the title reagent in boiling benzene gives parent hydrocarbons in good to moderate yields.
- Suzuki, Hitomi,Masuda, Reiko,Kubota, Hirohisa,Osuka, Atsuhiro
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p. 909 - 910
(2007/10/02)
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