10229-59-1Relevant articles and documents
Selective Deprotection of N -Tosyl Alkoxyamines Using Bistrifluoromethane Sulfonimide: Formation of Oxime Ethers
Azizi, Mohamed Salah,Cossy, Janine
supporting information, p. 2417 - 2421 (2018/11/23)
The detosylation of N -tosyl alkoxyamines was realized by treatment with benzaldehyde and bistrifluoromethane sulfonimide as the catalyst to afford the corresponding oxime ethers. The reaction is chemoselective as N -tosyl amines are not deprotected. A me
Sustainable Synthesis of Oximes, Hydrazones, and Thiosemicarbazones under Mild Organocatalyzed Reaction Conditions
Morales, Sara,Ace?a, José Luis,García Ruano, José Luis,Cid, M. Belén
, p. 10016 - 10022 (2016/11/02)
Pyrrolidine catalyzes very efficiently, presumably via iminium activation, the formation of acyloximes, acylhydrazones, and thiosemicarbazones derived from aromatic and aliphatic aldehydes using equimolar amounts of reagents and green solvents. Experimental simplicity and excellent yields after a simple filtration are the main advantages of the method, being an alternative to those currently available especially for the acyl derivatives, which do not work under uncatalyzed conditions. Its application to the synthesis of acyloximes by direct condensation between aldehydes and acylhydroxylamines is unprecedented.
O-Substituted N-oxy arylsulfinamides and sulfonamides in Michael reactions
Bonifacio, Vasco D. B.,Kumar, Rakesh P.,Prabhakar, Sundaresan,Lobo, Ana M.
scheme or table, p. 266 - 276 (2011/11/06)
O-Substituted N-oxy arylsulfinamides and sulfonamides undergo fast aza-Michael reaction in the presence of base and electron-deficient α,β-unsaturated olefins under mild conditions. With N-silyloxy benzenesulfinamides, no aza-Michael product is observed and a hetero aza-Brook type rearrangement takes place induced by the base. Room temperature N-desulfinylation of N-benzyloxybenzenesulfinamide is achieved using BF 3.Et2O. N-Alkoxy arylsulfonamides aza-Michael adducts are found to be generally highly stable under strongly acidic and basic conditions.
CONTROLLED RELEASE OF ACTIVE COMPOUNDS FROM DYNAMIC MIXTURES
-
, (2010/09/17)
The present invention relates to a dynamic mixture in the form of a dynamic mixture obtained by reacting together, in the presence of water, at least one O-substituted hydroxylamine or S-substituted thiohydroxylamine derivative with at least one perfuming
A metathesis-based approach to the synthesis of 2-pyridones and pyridines
Donohoe, Timothy J.,Fishlock, Lisa P.,Procopiou, Panayiotis A.
, p. 285 - 288 (2008/09/19)
(Chemical Equation Presented) The ring-closing metathesis reaction has been successfully employed to form a range of dihydropyridone intermediates, which are in the correct oxidation state to undergo a base-induced elimination to reveal the aromatic 2-pyridone. This mild and novel approach to six-membered heteroaromatic compounds then provides access to a wide variety of substituted pyridines in excellent overall yield.
Mechanistic aspects of the formation of aldehydes and nitriles in photosensitized reactions of aldoxime ethers
Peter De Lijser,Rangel, Natalie Ann,Tetalman, Michelle A.,Tsai, Chao-Kuan
, p. 4126 - 4134 (2008/02/04)
(Chemical Equation Presented) The photooxidation of a series of aldoxime ethers was studied by laser flash photolysis and steady-state (product studies) methods. Nanosecond laser flash photolysis studies have shown that chloranu (CA)-sensitized reactions of the O-methyl (1), O-ethyl (2), O-benzyl (3), and O-tert-butyl (4) benzaldehyde oximes result in the formation of the corresponding radical cations. In polar non-nucleophilic solvents such as acetonitrile, there are several follow-up pathways available depending on the structure of the aldoxime ether and the energetics of the reaction pathway. When the free energy of electron transfer (ΔGET) becomes endothermic, syn-anti isomerization is the dominant pathway. This isomerization pathway is a result of triplet energy transfer from CA to the aldoxime ether. For substrates with α-protons (aldoxime ethers 1-3), the follow-up reactions involve deprotonation at the α-position followed by β-scission to form the benziminyl radical (and an aldehyde). The benziminyl radical reacts to give benzaldehyde, the major product under these conditions. A small amount of benzonitrile is also observed. In the absence of α-hydrogens (aldoxime ether 4), the major product is benzonitrile, which is thought to occur via reaction of the excited (triplet) sensitizer with the aldoxime ether. Abstraction of the iminyl hydrogen yields an imidoyl radical, which undergoes a β-scission to yield benzonitrile. An alternative pathway involving electron transfer followed by removal of the iminyl proton was not deemed viable based on charge densities obtained from DFT (B3LYP/6-31G*) calculations. Similarly, a rearrangement pathway involving an intramolecular hydrogen atom transfer process was ruled out through experiments with a deuterium-labeled benzaldehyde oxime ether. Studies involving nucleophilic solvents have shown that all aldoxime ethers reacted with MeOH by clean second-order kinetics with rate constants of 0.7 to 1.2 × 107 M-1 s-1, which suggests that there is only a small steric effect in these reactions. The steady-state experiments demonstrated that under these conditions no nitrile is formed. This is explained by a mechanistic scheme involving nucleophilic attack on the nitrogen of the aldoxime ether radical cation, followed by solvent-assisted [1,3]-proton transfer and elimination of an alcohol, similar to the results obtained for a series of acetophenone oxime ethers.
Ruthenium-catalysed conversion of oxime ethers into nitriles
Anand, Naveen,Owston, Nathan A.,Parker, Alexandra J.,Slatford, Paul A.,Williams, Jonathan M.J.
, p. 7761 - 7763 (2008/02/12)
The conversion of oxime ethers into nitriles has been achieved under neutral conditions using Ru(CO)(PPh3)3H2 and the bidentate ligand Xantphos as the catalyst.
Indium mediated allylation of glyoxylate oxime ethers, esters and cyanoformates
Ritson, Dougal J.,Cox, Russell J.,Berge, John
, p. 1921 - 1933 (2007/10/03)
An indium mediated procedure has been developed for the allylation of activated O-functionalised oximes and nitriles as exemplified by a variety of glyoxylate derivatives. This method gives the corresponding free (or protected) amine in a one pot-process. The method is regiospecific and is carried out under remarkably mild conditions so that even oxime esters can be subjected to the typical reaction conditions.
o-Iodoxybenzoic Acid (IBX) as a Viable Reagent in the Manipulation of Nitrogen- and Sulfur-Containing Substrates: Scope, Generality, and Mechanism of IBX-Mediated Amine Oxidations and Dithiane Deprotections
Nicolaou,Mathison, Casey J. N.,Montagnon, Tamsyn
, p. 5192 - 5201 (2007/10/03)
o-Iodoxybenzoic acid (IBX), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the dehydrogenation of amines in addition to facilitating the oxidative cleavage of dithioacetals and dithioketals. Through the development of relevant IBX-based protocols, a plethora of useful synthetic intermediates, including imines, oximes, ketones, and aromatic N-heterocycles, were found to be readily accessible under notably mild conditions. Further investigation of these transformations led to the elucidation of valuable mechanistic details, resulting in the conclusion that they proceed via ionic rather than single electron transfer (SET) pathways.
New reactions of IBX: Oxidation of nitrogen- and sulfur-containing substrates to afford useful synthetic intermediates
Nicolaou,Mathison, Casey J. N.,Montagnon, Tamsyn
, p. 4077 - 4082 (2007/10/03)
New reactions for the synthetic toolbox: 2-lodoxybenzoic acid (IBX) was employed to access a diverse array of useful synthetic intermediates. Among other transformations, the developed chemistry converts amines into imines, dithianes into carbonyl groups, N-heterocycles into N-heteroaromatic compounds, and hydroxylamines into oximes in high yields.
