Photocatalytic Intramolecular C–H Amination Using <i>N</i>-Oxyureas as Nitrene Precursors
作者:Ryan A. Ivanovich、Dilan E. Polat、André M. Beauchemin
DOI:10.1021/acs.orglett.0c02200
日期:2020.8.21
Nitrenes are remarkable high-energy chemical species that enable direct C–N bond formation, typically via controlled reactions of metal-stabilized nitrenes. Here, in contrast, the combined use of photocatalysis with careful engineering of the precursor enabled C–H amination forming imidazolidinones and related nitrogen heterocycles from readily accessible hydroxylamine precursors. Preliminary mechanistic
The synthesis and some reactions of N-hydroxycarbamates
作者:E. Boyland、R. Nery
DOI:10.1039/j39660000346
日期:——
chloroformate, gave N-hydroxy-N-phenylurethane. Hydroxylamine hydrochloride and ethyl chloroformate yielded a product which changed into hydroxyurethane. Alkyl N-hydroxycarbamates and hydroxyurea gave O-xanthydryl derivatives. The N-hydroxycarbamates with aqueous dipotassium tetracyanonickelate(II) formed dipotassium tricyanonitrosylnickelate(II). No evidence of a Lossen-type rearrangement during the acid
羟胺和氯甲酸烷基酯在碱性介质中反应,以形成ñ - , - NO -二- ,和NNO -三烷氧羰基羟胺,依次。N-甲基羟胺类似地得到N-和NO-二烷氧基羰基-N-甲基-羟胺,O-甲基羟胺产生N-和NN-二烷氧基羰基-O-甲基羟胺。N-苯基羟胺与1当量的氯甲酸乙酯反应,得到N-羟基-N-苯基氨基甲酸酯。盐酸羟胺和氯甲酸乙酯产生产物,其变为羟基氨基甲酸酯。N-羟基氨基甲酸酯烷基和羟基脲得到O-黄羟基衍生物。所述Ñ -hydroxycarbamates用含水四氰二钾(II)而形成二钾tricyanonitrosylnickelate(II)。在这些羟氨基衍生物的酸和碱水解过程中,没有证据表明发生了洛森型重排。讨论了可能的水解机理。
Palladium-Catalyzed Decarboxylative Synthesis of Arylamines
作者:Qipu Dai、Peihe Li、Nuannuan Ma、Changwen Hu
DOI:10.1021/acs.orglett.6b02724
日期:2016.11.4
A novel approach has been developed for the synthesis of arylamines via the palladium-catalyzed intramoleculardecarboxylative coupling (IDC) of aroyloxycarbamates, obtained in situ by reacting aryl carboxylic acids with hydroxycarbamates. The reaction offers facile access to structurally diverse arylamines with the site-specific formation of the C(sp2)-N bond under mild conditions.
Rhodium-Catalyzed <i>ortho</i>
-Amidations in the Preparation of Thiadiazine 1-Oxides
作者:Ying Cheng、Wanrong Dong、Han Wang、Carsten Bolm
DOI:10.1002/chem.201602550
日期:2016.7.25
Rhodium‐catalyzed ortho‐amidations of sulfoximines lead to key intermediates for the preparation of thiadiazine 1‐oxides. Following a straightforward protocol, a variety of synthetically valuable compounds can be obtained, thus circumventing common multistep approaches towards potentially bioactive products.
Regioselective Synthesis of 2-Vinylanilines Using <i>O</i>-aroyloxycarba-mates by Sequential Decarboxylation/Amination/Heck Reaction
作者:Peihe Li、Nuannuan Ma、Jikun Li、Zheng Wang、Qipu Dai、Changwen Hu
DOI:10.1021/acs.joc.7b01020
日期:2017.8.4
ortho-substituted substrates, but also provides site-special to create new C(sp2)-N and C(sp2)-C(sp2) bonds. Mechanistic experiments suggest the cleavage of C(sp2)-COOH gives priority to C(sp2)-X bond in this reaction.