- A facile noncatalytic pathway for the nitrene transfer process: Expeditious access to aziridines
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A fast and efficient method has been developed for generation of sulfonyl nitrene from N,N-dibromo-p-toluenesulfonamide (TsNBr2) in the presence of a base without any catalyst. This method was applied to produce aziridines from different kinds of olefins within a short time in high yields. The Royal Society of Chemistry.
- Saikia, Indranirekha,Kashyap, Bishwapran,Phukan, Prodeep
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supporting information; experimental part
p. 2967 - 2969
(2011/04/24)
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- An improved synthesis of N-sulphonyl-1H-azepines under solid-liquid phase-transfer catalysis conditions
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The synthesis of novel N-sulphonyl-1H-azepines is described starting from arylsulphonyl chlorides in a one-pot operation making use of solid-liquid phase-transfer catalysis technique (benzene/sodium bicarbonate). Good yields were obtained under moderate reaction conditions.
- Ayyangar,Kumar,Srinivasan
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p. 499 - 502
(2007/10/02)
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- Photochemical Transformations, 65. The 3? -> 3?-Route to 1H-Azepines/Benzene Imines
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With several newly prepared substrates the influence of substituents upon the individual steps in the 3? -> 3?-route to 1H-azepines is more precisely defined: The C-unsubstituted 7-azanorbornadiene 2a, its 2,3-dichloro derivative 2b, the dimethyl 5,6-dichloro-2,3-dicarboxylate 2c, and the diesters 2d, e with dipolarophilic groups at C-1/N-7 are selectively isomerized by sensitized/direct photoexcitation into the azaquadricyclanes 29a-e, some of which are highly unstable.For the thermal conversion of the basic skeleton (N-Tos)29a the kinetic parameters have been determined (benzene): Ea = 28.0 +/- 0.2 kcal/mol, lg A = 15.7; ΔH* = 27.3 +/- 0.2 kcal/mol, ΔS* = 11.1 +/- 0.7 e.u.This barrier is lowered more efficiently by the chloro (29b, c) than by the methoxycarbonyl substituents (29f), with the former (latter) causing exclusive scission of the opposite (neighbouring) cyclopropane bonds.The intermediate azomethine ylides are captured with dipolarophilic reagents more or less efficiently depending on their substitution pattern.In the case of 29d(28d) the intramolecular addition of the unactivated yne component (37) at -30C is so fast, that azepine formation is almost totally suppressed (?2 + ?2 + Σ2>, 36?).The azepine/benzene imine equilibrium mixture 31c 32c (ca. 90:10) crystallizes as 31c (X-ray crystal structure analysis).
- Prinzbach, Horst,Bringmann, Horst,Fritz, Hans,Markert, Juergen,Knothe, Lothar,et al.
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p. 616 - 644
(2007/10/02)
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- Azides. Part V. A kinetic study of the formation of N-(p-toluenesulphonyl)-1H-azepine by thermolysis of p-toluenesulphonylazide in benzene under nitrogen pressure
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The course of thermolysis of p-toluenesulphonylazide (A) in benzene at 160 deg C and 40.1 atm of nitrogen pressure was followed by analysis of the reactants and products in the reaction mixture by hplc.The rate measurements indicate that the reaction follows first-order kinetics with respect to the formation of N-(p-toluenesulphonyl)-1H-azepine (B) and p-toluenesulphonamide (D).The concentration-time profile is consistent with the formation of p-toluenesulphonylanilide (C) from the azepine (B).The rate constants indicate that the azepine (B) decomposes to the anilide (C) at the same rate at which it is formed.
- Ayyangar, Nagaraj R.,Bambal, Ramesh B.,Nikalje, Dattatraya D.,Srinivasan, Kumar V.
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p. 887 - 890
(2007/10/02)
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- Pressure-induced Synthesis of an N-Sulphonyl-1H-azepine by Sulphonyl-nitrene Insertion into Benzene
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The thermal decomposition of toluene-p-sulphonyl azide (1) in an excess of benzene under a nitrogen atmosphere gave p-tosyl-1H-azepine (2), the yield of which increased with an increase in N2 pressure.
- Ayyangar, Nagaraj R.,Bambal, Ramesh B.,Lugade, Ananda G.
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p. 790 - 791
(2007/10/02)
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