95911-62-9Relevant academic research and scientific papers
Reactivity of 1-chloro-3-phenyldiazirines
Martinu, Tomas,Dailey, William P.
, p. 5012 - 5015 (2007/10/03)
p-Substituted 1-chloro-3-phenyldiazirines (5), the putative intermediates of the reaction of N,N,N′-trichlorobenzamidines (10) with excess of bromide ions, react further to afford mixtures of 3-bromo- (4) and 3-chloro-3-phenyldiazirines (6). The 6:4 ratio
Dimerization and trapping of diazirinyl radicals
Thompson, Robert A.,Francisco, Joseph S.,Grutzner, John B.
, p. 756 - 765 (2007/10/03)
Computational and experimental methods have been utilized to examine the facile dimerization of diazirinyl radicals. Two potential dimers were investigated using density functional theory. Both were shown to have low-barrier reaction coordinates leading t
Precise Control of the Formation of a Covalent and an Ionic Bond in Carbocation-Carbanion Combination Reactions
Takeuchi, Ken'ichi,Kitagawa, Toshikazu,Miyabo, Atsushi,Hori, Hideshi,Komatsu, Koichi
, p. 5802 - 5810 (2007/10/02)
The electronic effect on the selectivity of covalent or ionic bond formation was examined for the reaction of Kuhn's anion 1(1-) (C67H39(1-); tris(7H-dibenzofluorenylidenemethyl)methide ion) and 1-aryl-2,3-dicyclopropylcyclopropenylium ions.The carbocation stability was progressively changed by varying the substituent on the phenyl ring, while the steric effect was kept essentially unchanged.The cations having the p-chlorophenyl (2a(1+)), phenyl (2b(1+)), m-methylphenyl (2c(1+)), or m,m'-dimethylphenyl (2d(1+)) group gave a covalent product, whereas a carbocation-carbanion salt was obtained from the cations having the p-methylphenyl (2e(1+)) or p-methoxyphenyl (2f(1+)) group.The reduction potentials Ered of the cations, as determined by cyclic voltammetry, showed that the formation of the covalent or ionic product is switched by a small difference in stability ( 0.4 kcal/mol) between 2d(1+) and 2e(1+).In chloroform, the salts 1(1-)2e(1+) and 1(1-)2f(1+) were transformed into covalent forms 1-2e and 1-2f, which can exist only in solution.When 1-(2a-d) and 1(1-)2e,f(1+) were dissolved in DMSO, equilibrium between a covalent compound and ions was established.A plot of the free energy of heterolysis ΔG0het for 1-(2a-f) against the Ered of the corresponding cations 2a-f(1+) showed that ΔG0het decreases as the cation is more stabilized.The heterolysis in DMSO was shown to be enhanced by ca. 13 kcal/mol both by the steric congestion in the covalent molecules and the stabilization of the cyclopropenylium ions by solvation.
AZIDE AND FLUORIDE EXCHANGE REACTIONS OF HALODIAZIRINES
Moss, Robert A.,Terpinski, Jacek,Cox, D. Phillip,Denneey, Dorothy Z.,Krogh-Jespersen, Karsten
, p. 2743 - 2748 (2007/10/02)
Reactions of 3-aryl-3-bromodiazirines (11) with molten tetrabutylammonium fluoride at 25degC provide 65-74percent isolated vields of the novel corresponding 3-aryl-3-fluorodiazirines (12) Related reactions of 11 with tetrabutylammonium azide afford high yields of aryl nitriles.The latter reactions are believed to proceed through unstable intermediate 3-aryl-3-azidodiazirines (7).These reactions involve rate-determining formation of 7 and display kinetics which are first order in azide ion and bromodiazirine.The likely intermediacy of aryldiazirinium bromide ion pair between 11 and 7 is supported by a combination of salt effect, leaving group effect and Hammett studies.Molecular orbital calculations are employed to characterize azidodiazirines as well as the mode of their decomposition to nitriles.In particular, we consider the possible itermediacy of a 3-nitrenodiazirine or an azidocarbene.
