- Regio- and Enantioselective Formal Hydroamination of Enamines for the Synthesis of 1,2-Diamines
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The asymmetric formal hydroamination of enamines using a CuH catalyst is reported. The method provides a straightforward and efficient approach to the synthesis of chiral 1,2-dialkyl amines in good yields with high levels of enantioselectivities for a broad range of substrates, and should have significant value for the preparation of molecules bearing a 1,2-diamine motif.
- Yu, Lu,Somfai, Peter
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supporting information
p. 8551 - 8555
(2019/05/21)
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- O2-Mediated Oxidation of Aminoboranes through 1,2-N Migration
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In analogy to the classical reaction of C?B bonds with peroxides, the first oxidative functionalization of aminoboranes through a 1,2-N migration was realized. Readily available aliphatic nitro compounds are thereby transformed into N- and O-functionalized hydroxylamines in a single synthetic operation. Addition of hazardous peroxides is avoided. Instead, the insertion of O2, as the terminal oxidant, into Zn?C bonds provides the necessary peroxides. The required zinc organyls, in turn, are formed through a boron-to-zinc exchange, from an organoboronic ester byproduct of the nitro-to-aminoborane transformation.
- Rauser, Marian,Warzecha, Daniel P.,Niggemann, Meike
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supporting information
p. 5903 - 5907
(2018/05/14)
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- Selective Oxidation of Secondary Amines to N,N-Disubstituted Hydroxylamines by Choline Peroxydisulfate
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N,N-Disubstituted hydroxylamines were prepared directly from secondary amines by a reliable method using an oxidizing task-specific ionic liquid, choline peroxydisulfate. The operational simplicity, high selectivity, and green reaction conditions, make this method efficient and practical.
- Banan, Alireza,Valizadeh, Hassan,Heydari, Akbar,Moghimi, Abolghasem
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p. 2315 - 2319
(2017/10/06)
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- The oxidation of the alpha-carbon of amines in hydrothermal condition: An alternative synthetic route of compounds containing amide bond
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Here we report experimental evidence for the simple synthesis of N,N-diethylhydroxylamine and an amide bond formation reaction from oxidation of the alpha-carbon of tertiary amines by the reaction of triethylamine and hydrogen peroxide in hydrothermal conditions. It is proved that 120 C is a turning point: when the temperature is lower than that, the main product is N,N-diethylhydroxylamine as a result of a cope rearrangement reaction mechanism; on the contrary, the product is more complex and the main products are amides via a radical chain mechanism involving three steps: initiation, propagation, and oxidation, followed by decarbonylation and electrocyclization because the radical is easier to form under high temperature.
- Bai, Xueyin,Liu, Ziwei,Ye, Kaiqi,Wang, Yu,Zhang, Xianlong,Yue, Huijuan,Tian, Ge,Feng, Shouhua
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p. 319 - 321
(2014/01/06)
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- Catalytic method for preparing symmetrical and nonsymmetrical dialkylhydroxylamines
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A process of forming N,N-dialkylhydroxylamines (a class of compounds useful as oxygen scavengers in boiler water feed) by contacting an N-alkylhydroxylamine with an alkyl carbonyl compound to form a nitrone in situ or, alternatively, using previously formed alkylnitrone which is subjected to H2 and a hydrogenation catalyst.
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- Process of preparing hydroxyarylaldehydes
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An improvement in the process for preparing hydroxyarylaldehydes is disclosed where a phenolic compound is reacted with formaldehyde, in the presence of a catalyst such as a titanium or zirconium containing catalyst, optionally in the presence of a catalyst promoter, wherein the improvement is the addition of a yield effective amount of a modifier having the formula: STR1 where R1 is selected from the group consisting of: an alkyl group having from 1 to 12 carbon atoms, a cycloalkyl group that can have 5 and 6 carbon atoms, and an H, and where R2 is selected from the group consisting of: an alkyl group having from 1 to 12 carbon atoms, and a cyclo alkyl group that can have 5 to 6 carbon atoms; and where R1 and R2 can together form a cyclic group that can have 5 and 6 carbon atoms.
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- Hg-Sensitized Photolysis of Diethylamine in the Absence and Presence of O2 or N2O
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The Hg-sensitized photolysis of diethylamine (DEA) was studied in the absence and presence of O2 or N2O at room temperature.In the absence of foreign gases, the products were H2, CH3CH=NC2H5, and N,N'-diethylbutane-2,3-diamine (III), with respective quantum yields of 1.0, 1.0, and ca. 0.02.Thus CH3C.HNHC2H5 radicals are produced exclusively and they are removed by self reaction: 2CH3C.NHC2H5-> DEA+CH3CH=NC2H5 (4a) and 2CH3C.NHC2H5->diamine (III) (4b), with k4a/k4b=47.0+/-5.6.In the presence of O2 the radicals are scavenged exclusively by abstraction of the H atom on the nitrogen to give the imine CH3CH=NC2H5 as the exclusive product :CH3CH.NHC2H5+O2-> CH3CH=NC2H5+ H2O (5).The Hg-sensitized photolysis of N2O gives O(3P)atoms, which in the presence of DEA react to give the imine and (C2H5)NOH (DEHA) as products in concerted parallel steps: O(3P)+(C2H5)2NH -> CH3CH=NC2H5+H2O (9a) and O(3P)+ (C2H5)2NH-> (C2H5)2NOH (9b), with k9a/k9b ca. 9.5 +/- 1.7.
- DeStefano, George,Heicklen, Julian
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p. 4637 - 4640
(2007/10/02)
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- REARRANGEMENTS OF N-SUBSTITUTED HYDROXYLAMINES - POTENTIAL GENERATORS OF NITRENIUM IONS
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The transformations of N-substituted hydroxylamines into Schiff bases by the action of phosphorus pentachloride, which have only been observed previously in the aromatic series (the so-called Stieglitz rearrangement), also occur among aliphatic monosubstituted and N,N-disubstituted hydroxylamines and their salts.The Schiff bases which form can be regarded as the product from stabilization of the intermediate nitrenium ions RNH+ and R2N+, but it is not possible to confirm the participation of the latter in reactions by interaction with the solvent.
- Stolyarov, B. V.,Krylov, A. I.
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p. 1523 - 1528
(2007/10/02)
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