621-07-8Relevant articles and documents
Late Stage Functionalization of Secondary Amines via a Cobalt-Catalyzed Electrophilic Amination of Organozinc Reagents
Gra?l, Simon,Chen, Yi-Hung,Hamze, Clémence,Tüllmann, Carl Phillip,Knochel, Paul
supporting information, p. 494 - 497 (2019/01/14)
A general preparation of polyfunctional hydroxylamine benzoates from the corresponding secondary amines is reported. This convenient synthesis allows the setup of a late-stage functionalization of various secondary amines, including pharmaceuticals and peptidic derivatives. Thus, a cross-coupling of hydroxylamine benzoates with various alkyl-, aryl-, and heteroaryl-zinc chlorides in the presence of 5 mol % CoCl2 (25 °C, 2 h) provides a range of polyfunctional tertiary amines. This method was used to prepare penfluridol and gepirone.
Enantioselective Synthesis of 4-Aminotetrahydroquinolines via 1,2-Reductive Dearomatization of Quinolines and Copper(I) Hydride-Catalyzed Asymmetric Hydroamination
Xu-Xu, Qing-Feng,Zhang, Xiao,You, Shu-Li
supporting information, p. 5357 - 5362 (2019/09/06)
A 1,2-reductive dearomatization of quinolines and copper(II) acetate monohydrate/(R,R)-Ph-BPE/P(p-tolyl)3-catalyzed enantioselective hydroamination sequence was developed, affording diverse 4-amino-1,2,3,4-tetrahydroquinolines with high levels of enantioselectivity in either a stepwise or one-pot fashion. Pleasingly, internal cis-cyclic alkenes, which are challenging substrates in copper hydride-catalyzed enantioselective hydroamination reactions, were transformed efficiently under mild conditions.
Copper-Catalyzed Ring Opening of Benzofurans and an Enantioselective Hydroamination Cascade
Xu-Xu, Qing-Feng,Liu, Qiang-Qiang,Zhang, Xiao,You, Shu-Li
supporting information, p. 15204 - 15208 (2018/10/24)
A copper(II) acetate/(R)-DTBM-SEGPHOS-catalyzed ring opening of benzofurans and enantioselective hydroamination cascade with dimethoxymethylsilane (DMMS) and hydroxylamine esters is described. Starting from readily available substituted benzofurans, a series of chiral N,N-dibenzylaminophenols, which are of high interest in pharmaceutical chemistry, were obtained with excellent enantioselectivities (up to 66 % yield, 94 % ee).
Selective Oxidation of Secondary Amines to N,N-Disubstituted Hydroxylamines by Choline Peroxydisulfate
Banan, Alireza,Valizadeh, Hassan,Heydari, Akbar,Moghimi, Abolghasem
, p. 2315 - 2319 (2017/10/06)
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.
Synthesis and characterization of N-methyl and N-benzyl cinnamohydroxamic acids
Rajput, Surendra K.,Patel, Anita,Bapat, Kishor N.
, p. 885 - 887 (2017/02/10)
N-methyl and N-benzyl cinnamohydroxamic acid was prepared by coupling reaction between N-methyl hydroxylamine and N-benzyl hydroxylamine with cinnamoyl chloride. The compounds were structurally characterized with 1H NMR, IR and elemental analysis.
Synthesis of N,N,O-Trisubstituted Hydroxylamines by Stepwise Reduction and Substitution of O-Acyl N,N-Disubstituted Hydroxylamines
Dhanju, Sandeep,Crich, David
, p. 1820 - 1823 (2016/05/19)
Diverse N,N,O-trisubstituted hydroxylamines, an under-represented group in compound collections, are readily prepared by partial reduction of N-acyloxy secondary amines with diisobutylaluminum hydride followed by acetylation and reduction of the so-formed O-acyl-N,N-disubstituted hydroxylamines with triethylsilane and boron trifluoride etherate. Use of carbon nucleophiles in the last step, including allyltributylstannane, silyl enol ethers, and 2-methylfuran, gives N,N,O-trisubstituted hydroxylamines with branching α- to the O-substituent. N,N-Disubstiuted hydroxylamines are conveniently prepared by reaction of secondary amines with dibenzoyl peroxide followed by diisobutylaluminum hydride reduction.
The Reactivity of Difluorocarbene with Hydroxylamines: Synthesis of Carbamoyl Fluorides
Baars, Hannah,Engel, Julien,Mertens, Lucas,Meister, Daniela,Bolm, Carsten
supporting information, p. 2293 - 2299 (2016/07/29)
Carbamoyl fluorides are formed in reactions of hydroxylamines with difluorocarbene generated from sodium bromodifluoroacetate as readily available and non-toxic carbene precursor. The process shows a high functional group tolerance, and the reaction path has been rationalized by computational calculations. (Figure presented.) .
O-trifluoromethylation of N,N-disubstituted hydroxylamines with hypervalent iodine reagents
Matousek, Vaclav,Pietrasiak, Ewa,Sigrist, Lukas,Czarniecki, Barbara,Togni, Antonio
supporting information, p. 3087 - 3092 (2014/06/09)
A mild trifluoromethylation reaction of N,N-disubstituted hydroxylamines that is tolerant towards a variety of functional groups, including nitriles, alcohols, ketones, esters, amides, imides, and nitrogen heterocycles, is reported. The key feature of this reaction is the activation of the CF 3 reagent with either trimethylsilyl triflate or LiClO4 and partial or full deprotonation of the substrate with tetramethylguanidine or lithium diisopropylamide. Products were obtained in up to 80 % yield. Preliminary mechanistic studies suggested that the reaction follows a radical pathway in which the deprotonated hydroxylamine and a Lewis or Bronsted acid activated CF3 reagent engages in a single-electron-transfer step to generate a pair of radicals that recombine to afford the desired product. The trifluoromethylation procedure was successfully used in the modification of secondary nitrogen groups of pharmaceutically relevant targets (Fluoxetine and Mefloquine), which afforded new derivatives containing a novel N-trifluoromethoxy moiety. Copyright
Methyltrioxorhenium-catalysed oxidation of secondary amines to nitrones in ionic liquids
Meciarova, Maria,Mojzesova, Melinda,Sebesta, Radovan
, p. 51 - 58,8 (2020/08/20)
Nitrones serve as starting materials for the synthesis of many heterocycles. Oxidation of secondary amines using hydrogen peroxide and the catalytic amount of methyltrioxorhenium in ionic liquids is a useful method for the preparation of nitrones. Ultrasonic irradiation and ionic liquids have a positive influence on the reaction. The nitrones required were isolated in good yields. Corresponding hydroxylamines, which can be easily oxidised to nitrones, often accompanied the main products. Methyltrioxorhenium in ionic liquids was re-used in several reaction cycles without any deteriorating effect on the course of the reaction.
Highly diastereoselective anti-dihydroxylation of 3-N,N- dibenzylaminocyclohex-1-ene N-oxide
Aciro, Caroline,Davies, Stephen G.,Kurosawa, Wataru,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.
supporting information; experimental part, p. 1333 - 1336 (2009/09/27)
Oxidation of 3-N,N-dibenzylaminocyclohex-1-ene N-oxide in the presence of Cl3CCO2H proceeds with high levels of anti- diastereoselectivity (97% de), with no competing side reactions, allowing access to 1,2-anti-2,3-anti-3-aminocycloh