19555-50-1Relevant academic research and scientific papers
Studies of Tetriary Amine Oxides. 9. Thermal Rearrangement of 1-(4-Substituted-phenyl)piperidine N-Oxides to the Corresponding N-Hydroxylamines
Khuthier, Abdul-Hussain,Al-Mallah, Khawla Y.,Hanna, Salim Y.,Abdulla, Noor-Aldeen I.
, p. 1710 - 1713 (1987)
(4-Substituted - phenyl)piperidine N-oxides undergo a thermal rearrangement to O-arylhydroxylamines.Electron withdrawing substituents are essential for the rearrangement and must be ortho or para relative to the N-O function.The reaction has been found to be first order in substrate when rates were measured in dioxane, and the activation parameters were calculated.The order of reactivity in this rearrangement is NO2 >> CN > COPh > COMe > COOEt > CONH2.The rates correlate very well with ?- constants and the ρ value was positive and large (+3.6) pointing to a highly po lar activated complex with an electron-rich reaction center.All results strongly support an intramolecular cyclic mechanism.
Highly Chemoselective Deoxygenation of N-Heterocyclic N-Oxides Using Hantzsch Esters as Mild Reducing Agents
An, Ju Hyeon,Kim, Kyu Dong,Lee, Jun Hee
supporting information, p. 2876 - 2894 (2021/02/01)
Herein, we disclose a highly chemoselective room-temperature deoxygenation method applicable to various functionalized N-heterocyclic N-oxides via visible light-mediated metallaphotoredox catalysis using Hantzsch esters as the sole stoichiometric reductant. Despite the feasibility of catalyst-free conditions, most of these deoxygenations can be completed within a few minutes using only a tiny amount of a catalyst. This technology also allows for multigram-scale reactions even with an extremely low catalyst loading of 0.01 mol %. The scope of this scalable and operationally convenient protocol encompasses a wide range of functional groups, such as amides, carbamates, esters, ketones, nitrile groups, nitro groups, and halogens, which provide access to the corresponding deoxygenated N-heterocycles in good to excellent yields (an average of an 86.8% yield for a total of 45 examples).
Tertiary amine oxidation using HOF-CH3CN: A novel synthesis of N-oxides
Dayan, Sharon,Moshe, Kol,Rozen, Shlomo
, p. 1427 - 1430 (2007/10/03)
HOF·CH3CN, probably the best oxygen transfer agent organic chemistry has to offer, is easily made by bubbling diluted fluorine (10-15%) through aqueous acetonitrile solution. Used as formed without any isolation or purification, it reacts with various tertiary amines such as pyridine derivatives, polyaromatic nitrogen containing compounds and aliphatic and alicyclic ones to form the corresponding N-oxides. When two nitrogen atoms are present it is possible to make both the N-monoxides and the N,N-dioxides. The reaction times are short (a few minutes), conditions are very mild (0-25 °C) and the yields range from good to excellent (70-95%).
