- Nickel-Catalyzed Regio- And Stereospecific C-H Coupling of Benzamides with Aziridines
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A nickel-catalyzed C-H coupling of 8-aminoquinoline-derived benzamides with aryl- and alkyl-substituted aziridines has been disclosed. The current strategy provides direct access to benzolactams by the C-H alkylation-intramolecular amidation cascade event with the concomitant removal of the aminoquinoline auxiliary. The regioselectivity of ring opening of aziridines can be controlled by the substituents. The reaction with chiral aziridines proceeds with inversion of configuration, thus suggesting an SN2-type nucleophilic ring-opening pathway.
- Hirano, Koji,Miura, Masahiro,Xu, Shibo
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p. 5471 - 5475
(2021/07/26)
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- Modular One-Step Three-Component Synthesis of Tetrahydroisoquinolines Using a Catellani Strategy
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Reported is a modular one-step three-component synthesis of tetrahydroisoquinolines using a Catellani strategy. This process exploits aziridines as the alkylating reagents, through palladium/norbornene cooperative catalysis, to enable a Catellani/Heck/aza-Michael addition cascade. This mild, chemoselective, and scalable protocol has broad substrate scope (43 examples, up to 90 % yield). The most striking feature of this protocol is the excellent regioselectivity and diastereoselectivity observed for 2-alkyl- and 2-aryl-substituted aziridines to access 1,3-cis-substituted and 1,4-cis-substituted tetrahydroisoquinolines, respectively. Moreover, this is a versatile process with high step and atom economy.
- Qian, Guangyin,Bai, Miao,Gao, Shijun,Chen, Han,Zhou, Siwei,Cheng, Hong-Gang,Yan, Wei,Zhou, Qianghui
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p. 10980 - 10984
(2018/07/30)
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- Observations on the modified wenker synthesis of aziridines and the development of a biphasic system
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A cheap and reliable process for the modified Wenker cyclization to afford aziridines has been achieved using biphasic conditions for a range of amino alcohol starting materials. A 100 mmol "one-pot" process has also been devised, and the enantiopurity of the starting amino alcohol is retained in the aziridine product.
- Buckley, Benjamin R.,Patel, Anish P.,Wijayantha
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p. 1289 - 1292
(2013/04/10)
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- An expedient in situ preparation of symmetrical 1,4-dibenzylpiperazines from benzyl bromides and 2-bromoethylamine hydrobromide
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A straightforward synthesis of a variety of 1,4-bis-benzylpiperazines from benzyl halides and 2-bromoethylamine hydrobromide is described.
- Bradley, Lynn M.,Nardone, Michael J.,Hunt, David A.
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scheme or table
p. 5613 - 5614
(2010/10/21)
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- Oxidation of N-benzyl aziridine by molecular iodine: Competition of electron transfer and heterolytic pathways
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Excess N-benzyl aziridine (1) reacts with I2 to afford dimer 2, tetramer 3, benzaldehyde (4), and iodoamine 5. The reaction is interpreted as occurring by both electron transfer (ET) and heterolytic mechanisms. An ET mechanism is substantiated
- Caproiu, Miron,Florea, Cristina,Galli, Carlo,Petride, Aurica,Petride, Horia
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p. 1037 - 1043
(2007/10/03)
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- Enantioselective synthesis of β-hydroxy amines and aziridines using asymmetric transfer hydrogenation of α-amido ketones
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A rapid, expedient and enantioselective method for the synthesis of β-hydroxy amines and monosubstituted aziridines in up to 99% e.e., via asymmetric transfer hydrogenation of α-amido ketones, is described. Copyright (C) 2000 Elsevier Science Ltd.
- Kawamoto, Aparecida,Wills, Martin
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p. 3257 - 3261
(2007/10/03)
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- Preparation of N-arylmethyl aziridine derivatives, 1,4,7,10-tetraazacyclododecane derivatives obtained therefrom and N-arylmethyl-ethanol-amine sulphonate esters as intermediates
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PCT No. PCT/GB96/00552 Sec. 371 Date Dec. 2, 1997 Sec. 102(e) Date Dec. 2, 1997 PCT Filed Mar. 8, 1996 PCT Pub. No. WO96/28420 PCT Pub. Date Sep. 19, 1996Aziridines may be subjected to a cyclooligomerization reaction to produce polyazacycloalkane compounds useful for example in the preparation of chelating agents for use in diagnostic imaging contrast agents. N-benzyl-aziridine in particular is useful as it can be cyclotetramerized and debenzylated to yield cyclen, a key intermediate in chelating agent preparation. The invention provides a particularly attractive route to production of N-benzyl and other N-arylmethyl aziridines of formula (I) where each R1 is independently hydrogen or a group AR and Ar is an optionally substituted phenyl group. The process comprises reacting a purified N-arylmethylethanolaminesulphonate ester with a base. N-arylmethyl-ethanolamine sulphonate ester of the formula R'NHCH2CH2OSO3H, wherein the N-arylmethyl group R' is an N-(bisarylmethyl) or N-(triarylmethyl) group, as intermediates. In a further aspect, the invention provides compounds of formula (II) where Ar and R1 are as hereinabove defined and at least two differing ArCHR21 moieties are present.
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- The oxidation of N-benzylaziridine catalyzed by iron porphyrin: Radical versus electron transfer mechanism
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A change in the mechanism of biomimetic oxidation of tertiary amines in response to appropriate structural features of the substrate, emerges from the investigation of the product pattern from N-benzylaziridine under bona fide radical or electron transfer conditions. This substrate is an amine endowed with a high oxidation potential as a result of steric constraint. Consequently, the hydrogen atom transfer route of oxidative N-dealkylation competes favorably with the electron transfer route, which is the mechanism observed for the reaction of conventional tertiary amines with metalloporphyrins and oxygen donors.
- Cuppoletti, Andrea,Dagostin, Claudio,Florea, Cristina,Galli, Carlo,Gentili, Patrizia,Lanzalunga, Osvaldo,Petride, Aurica,Petride, Horia
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p. 2993 - 2999
(2007/10/03)
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- Formation of azomethine ylids by thermolysis of oxazolidines. Study of the reaction in solution and in the gaseous phase
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Thermolysis of oxazolidines leads to azomethine ylids via cycloreversion.In the liquid phase, these intermediates then give 1-3 dipolar cycloaddition; in the gaseous phase, they lead to aziridines.With an alkyl group in position 2, we observed also the formation of enamines.The effect of substituents on both the cycloreversion reaction and the evolution of azomethine ylids was studied.The mechanism of the process tautomerism aziridine -> azomethine ylid -> enamine is discussed.Keywords - azomethine ylids / oxazolidines / cycloreversion / aziridines / enamines / tautomerism
- Bureau, R.,Mortier, J.,Joucla, M.
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p. 584 - 596
(2007/10/02)
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- Acid-Catalyzed Decomposition of 1-Alkyltriazolines: A Mechanistic Study
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1-Alkyltriazolines are five-membered cyclic triazenes containing the unusual Z-configuration for the triazene moiety.The hydrolytic decomposition of these compounds in aqueous or mixed acetonitrile-aqueous buffers leads predominantly to the formation of the corresponding 1-alkylaziridines and lesser amounts of 2-(alkylamino)ethanols, alkylamines, and acetaldehyde.The latter two products presumably result from hydrolysis of a rearrangement produkt, N-ethylidenealkylamine.Neither the nature of the 1-alkyl group nor the pH of the medium greatly influences the product distribution, although decomposition in purely aqueous buffers slightly reduces the aziridine yields.The rate of hydrolysis of 1-alkyltriazolines is about twice as fast as that of the analogous acyclic 1,3,3-trialkyltriazenes and varies in the order tert-butyl > isopropyl > ethyl > butyl > methyl > propyl > benzyl.The mechanism of the decomposition is specific acid-catalyzed (A1) involving rapid reversible protonation followed by rate-limiting formation of a 2-(alkylamino)ethyldiazonium ion.The slopes of the log kobs versus pH plots are near -1.0.The solvent deuterium isotope effect, kH2O/kD2O, is in all cases methyl > ethyl.
- Smith, Richard H.,Wladkowski, Brian D.,Taylor, Jesse E.,Thompson, Erin J.,Pruski, Brunon,et al.
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p. 2097 - 2103
(2007/10/02)
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- Substituted amine derivatives, their production and use
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Substituted amino derivatives represented by the formula: STR1 wherein R1 and R2 each stand for an acyclic hydrocarbon residue or an alicyclic hydrocarbon residue; R3 and R4 each stand for hydrogen or a hydrocarbon residue optionally containing hetero-atom(s); A stands for a carbon chain having two or more carbon atoms optionally containing ether linkage or sulfide linkage, which may be substituted and which may per se form a ring; X1 and X2 each stand for oxygen atom or sulfur atom; and Y stands for amino group or an organic residue bonded through nitrogen atom, which may form a ring by combining with a carbon atom constituting A; and their salts have anti-arrhythmic activity and are useful for prevention and treatment of a variety of arrhythmias.
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- Artificial Transport of Amino-acid, Oligopeptide, and Related Anions by Macrocyclic Polyamine-Transition Metal Complex Carriers
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Transition-metal complexes of the macrocylic polyamine, 1,4,7,10-tetrabenzyl-1,4,7,10-tetra-azacyclododecane have been shown to be new and powerful 'metallo-carriers' for the transport of amino-acid and oligopeptide derivatives.Their transport properties are generally different from previously reported systems, and are essentially controlled by factors such as the nature of the central metal ion, and the antiport anion.The metallo-carriers described provide both a successful example of artificial oligopeptide transport, and a unique and interesting transport phenomenon across a chloroform liquid membrane.
- Tsukube, Hiroshi
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