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
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.
α-Nitrosostyrenes as Three-Atom Units for the (3+1) Cyclization Reaction: Facile Access to 2,3-Dihydrodiazete <i>N</i>-Oxides and Their Diversified Synthetic Conversions
structurally unique and hitherto unexplored 2,3-dihydrodiazete N-oxides in moderate to high yields. The products possess a highly strained four-membered ring structure containing two nitrogen atoms. The synthetic applicability of the products was also demonstrated by many important conversions to diverse nitrogen-containing compounds.
<i>N</i>-Sulfonyloxy Carbamates as Reoxidants for the Tethered Aminohydroxylation Reaction
作者:Timothy J. Donohoe、Majid J. Chughtai、David J. Klauber、David Griffin、Andrew D. Campbell
DOI:10.1021/ja057389g
日期:2006.3.1
for the tetheredaminohydroxylation (TA) reaction is reported. These new conditions obviate the requirement for lithium hydroxide and tBuOCl in the oxidation mixture. In addition to providing aminohydroxylation products in good yields, the catalyst loadings can be reduced to just 1 mol % osmium. Moreover, for the first time, homoallylic alcohols are now viable substrates for the TA reaction.
Visible-Light-Promoted Intermolecular Oxidative Dearomatization of β-Naphthols with <i>N</i>
-Hydroxycarbamates
作者:Yuan-Zheng Cheng、Kai Zhou、Min Zhu、La-Ao-Chuan Li、Xiao Zhang、Shu-Li You
DOI:10.1002/chem.201803149
日期:2018.8.27
An intermolecular oxidative dearomatization of β‐naphthols with N‐hydroxycarbamates promoted by visible light was realized by means of photogenerated β‐naphthol radical cation intermediates. With a commercially available organic dye, the naphthalenones bearing a fully substituted stereogenic center were obtained with up to 92 % yield under aerobic conditions (26 examples). In addition, the rearrangement
通过光生β-萘酚自由基阳离子中间体实现了N-羟基氨基甲酸酯在β-萘酚的分子间氧化脱芳香化作用。使用可商购的有机染料,在有氧条件下以高达92%的产率获得带有完全取代的立体异构中心的萘酮(26个实例)。此外,仅在存在Cs 2 CO 3的情况下,才可以将CO偶联产物重排至CN偶联化合物。这种转化同时提供了一种吸引人的,合成上有用的方法来获得胺类脱芳香化化合物。