157728-61-5Relevant articles and documents
Nucleophilic intermolecular chemistry and reactivity of dimethylcarbene
Cang, Hui,Moss, Robert A.,Krogh-Jespersen, Karsten
, p. 2730 - 2737 (2015)
Experimental and computational studies find that dimethylcarbene (DMC), the parent dialkylcarbene, is both predicted to be and functions as a very reactive nucleophilic carbene in addition reactions with five simple alkenes. Activation energies and enthal
Oxidative cleavage of the C=N bond during singlet oxygenations of amidoximates
?cal, Nüket,Erden, Ihsan
, p. 4765 - 4767 (2007/10/03)
Amidoximes are inert toward singlet oxygen (1O2), however, the photooxygenation of amidoximate anions proceeds smoothly and in high yield to give mixtures of amides and nitriles. The mechanism of these reactions appears to involve carbonyl oxide intermediates. The oxidative cleavage of amidoximates closely resembles the results obtained from nitric oxide synthase (NOS) oxidations of N-hydroxyarginine.
Kinetics of the Competitive 1,2-Carbon Migrations of an Unsymmetrically Substituted Cyclopropylchlorocarbene
Moss, Robert A.,Liu, Weiguo,Krogh-Jespersen, Karsten
, p. 13413 - 13418 (2007/10/02)
Photolysis of 3-(2,2-dimethylcyclopropyl)-3-chlorodiazirine (4) at 25 deg C in pentane affords 81 percent of the 1,2-C migration products 1-chloro-3,3-dimethylcyclobutene (5) and 2-chloro-3,3-dimethylcyclobutene in a 4.8:1 distribution, as well as 19 percent of the fragmentation products, isobutene, and chloroacetylene.Experiments in the presence of the carbene trap trimethylethylene point to product formation from the electronically excited diazirine (4*), which affords 19-20 percent of fragmentation products, ca. 17 percent of 5 and 6 (3.8:1), and ca. 63 percent of 2,2-dimethylcyclopropylchlorocarbene (3).The carbene ring expands to 5 and 6 (5.2:1).Laser flash photolytic studies afford absolute rate constants for 3 -> 5 (1.3 * 106 s-1) and 3 -> 6 (2.5 * 105 s-1).The 5-fold preference of 3 for CH2 migration (to 5) over CMe2 migration (to 6) is attributed to differential steric affects.Ab initio calculations afford structures and energies for 3 and the CH2 and CMe2 transition state (8-CH2 and 8-CMe2).The calculations agree with the experimental findings in that ΔG* for CH2 migration is found to be 1.4 kcal/mol less than ΔG* for CMe2 migration, corresponding to a computed 10-fold kinetic preference for CH2 migration.The expected additional steric congestion is apparent in the 8-CMe2 transition state.
Process for the production of cyclopropanenitrile derivatives
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, (2008/06/13)
A process for the production of cyclopropanenitrile derivatives. A diol of the formula: STR1 wherein R1 and R2 are the same or different and each is a hydrogen atom, a C1 -C6 alkyl group, branched or unbranched,
Conversion of trifluoromethyl groups into nitrile functions during cyclization of hexafluoroiodoalkanes with sodium amide
Hanack, M.,Ullmann, J.
, p. 249 - 257 (2007/10/02)
The cyclization of (CF3)CHCH2CIR1CHR2R3 (1) (1a: R1 = Me, R2 = H; 1b: R1 = H, R2 = R3 = Me; 1c: R1 = R2 = R3 = Bun) with so
Conformational Analysis of the Cyclopropylacyl, Oxiranylacyl, and Aziridinylacyl Radicals by Electron Spin Resonance Spectroscopy
Davies, Alwyn G.,Sutcliffe, Roger
, p. 1483 - 1488 (2007/10/02)
A series of ring-substituted cyclopropylacyl, oxiran-2-ylacyl, and aziridin-2-ylacyl radicals have been prepared principally by the reaction of photolytically generated t-butoxyl radicals with the corresponding aldehydes.The e.s.r. spectra show that the cyclopropylacyl ?-radicals exist in s-cis- and s-trans-conformations of approximately equal stability, in which the plane of the acyl group bisects the ring (as it does in the parent aldehyde), and simulation of the spectra through the region of intermediate rates of exchange show that the barrier to rotation is ca. 17.5 kJ*mol-1.The behaviour of the trans-2-ethoxycarbonylcyclopropylacyl and 2,2-dimethylcyclopropylacyl radicals is similar.The oxiranylacyl and trans-3-methyloxiranylacyl radicals exist in the same two conformations with a rather lower barrier, and the N-alkylaziridinylacyl radicals appear to have a lower barrier still.
Azetidines. 5. Reaction of 1,1,3,3-Tetramethyl- and 1-Benzyl-1,3,3-trimethylazetidinium Ions with Butyllithium and Phenyllithium. Deuterium Labeling as a Mechanistic Probe
Wills, Max T.,Wills, Irene E.,Dollen, Lawrence Von,Butler, Barry L.,Porter, John,Anderson, Arthur G.
, p. 2489 - 2498 (2007/10/02)
The reactions of 1,1,3,3-tetramethylazetidinium iodide (1) and 1-benzyl-1,3,3-trimethylazetidinium bromide (7) with butyllithium and with phenyllithium were studied in ether.The products from the reaction of 1 with butyllithium were 1,3,3-trimethylpyrrolidine (2), 3,3-dimethyl-4-(methylamino)-1-butene (3), 1-(dimethylamino)-2,2-dimethylheptane (4), neopentylpyrrolidine (5), and 1-(dimethylamino)-2,2-dimethylcyclopropane (6).With phenyllithium, 1 gave 2 and 1-(dimethylamino)-2,2-dimethyl-3-phenylpropane (11).With butyllithium, 7 gave 2-phenyl-1,4,4-trimethylpyrrolidine (8), 1-benzyl-3,3-dimethylpyrrolidine (9), and 1-neopentyl-2-phenylpyrrolidine (10).The reaction of phenyllithium with 7 gave only 8 and 9.Mechanistic information was obtained by labeling 1 with deuterium in three different ways: N-methyl-d3, 2,2-d2, and N-methyl-d3-2,2-d2.A primary kinetic isotope effect of 9.4 was found for the formation of 2 from 1-N-methyl-d3.When 2 was formed from 1-2,2-d2, a secondary kinetic isotope effect of 1.17 was measured.The formation of 4 from 1-2,2-d2 was accompanied by a primary kinetic isotope effect of 4.7, suggesting a carbene intermediate.Ylide carbanions involving decomposition to a carbene carbanion in the formation of 3 and an azomethine ylide in the formation of 5 and 9 are probable intermediates.It is postulated that the azomethine ylides react with ethylene formed from the reaction of butyllithium with the solvent ether by means of a concerted (4 + 2) cycloaddition reaction.A primary kinetic isotope effect of 20 was found for the formation of pentylbenzene from dibenzyldimethylammonium bromide and butyllithium.