593-61-3Relevant academic research and scientific papers
Photochemistry and Dynamics of Vinyl Bromide and Vinyl Iodide in Rare Gas Matrices
Paolucci, Dora M.,Gunkelman, Katherine,McMahon, Michael T.,McHugh, Jeanine,Abrash, Samuel A.
, p. 10506 - 10510 (1995)
Dilute solid solutions of vinyl bromide in krypton and vinyl iodide in argon were photolyzed at 10 K with a medium pressure mercury lamp.When the vinyl bromide is photolyzed, both hydrogen bromide-acetylene complexes and bromoacetylene are observed as photolysis products.Kinetic analysis shows that the hydrogen bromide-acetylene complexes are the only primary photolysis products and that the bromoacetylene is formed by secondary photolysis of the hydrogen bromide-acetylene complexes.Similar results are observed for the photolysis of vinyl iodide, with hydrogen iodide-acetylene complexes the only primary products and iodoacetylene observed as a secondary photolysis product of the hydrogen iodide-acetylene complex.We present the first reported vibrational frequencies for the HI-acetylene complex.
Gold(III)-catalyzed chemoselective annulations of anthranils with N-allylynamides for the synthesis of 3-azabicyclo[3.1.0]hexan-2-imines
Song, Lina,Tian, Xianhai,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
supporting information, p. 9007 - 9010 (2019/08/01)
We herein report the gold(iii)-catalyzed selective annulation of anthranils with N-allylynamides under mild conditions. By trapping the in situ-generated α-imino gold carbenes, 3-azabicyclo[3.1.0]hexan-2-imines were obtained in high synthetic efficiency. The reaction, which can be conducted in the gram scale, tolerates electron-rich and electron-deficient anthranils as well as a diverse set of functionalized ynamides (aryl- and alkyl-substituted terminal).
Formation of fulvene in the reaction of C2H with 1,3-butadiene
Lockyear, Jessica F.,Fournier, Martin,Sims, Ian R.,Guillemin, Jean-Claude,Taatjes, Craig A.,Osborn, David L.,Leone, Stephen R.
, p. 232 - 245 (2015/04/14)
Abstract Products formed in the reaction of C2H radicals with 1,3-butadiene at 4 Torr and 298 K are probed using photoionization time-of-flight mass spectrometry. The reaction takes place in a slow-flow reactor, and products are ionized by tunable vacuum-ultraviolet light from the Advanced Light Source. The principal reaction channel involves addition of the radical to one of the unsaturated sites of 1,3-butadiene, followed by H-loss to give isomers of C6H6. The photoionization spectrum of the C6H6 product indicates that fulvene is formed with a branching fraction of (57 ± 30)%. At least one more isomer is formed, which is likely to be one or more of 3,4-dimethylenecyclobut-1-ene, 3-methylene-1-penten-4-yne or 3-methyl-1,2-pentadien-4-yne. An experimental photoionization spectrum of 3,4-dimethylenecyclobut-1-ene and simulated photoionization spectra of 3-methylene-1-penten-4-yne and 3-methyl-1,2-pentadien-4-yne are used to fit the measured data and obtain maximum branching fractions of 74%, 24% and 31%, respectively, for these isomers. An upper limit of 45% is placed on the branching fraction for the sum of benzene and 1,3-hexadien-5-yne. The reactive potential energy surface is also investigated computationally. Minima and first-order saddle-points on several possible reaction pathways to fulvene + H and 3,4-dimethylenecyclobut-1-ene + H products are calculated.
C2 molecule: formation from bromoacetylene and reactions with cyclohexene or 2,3-dimethyl-2-butene
Galy, Nicolas,Doucet, Henri,Santelli, Maurice
scheme or table, p. 695 - 697 (2010/04/02)
The C2 molecule (1,2-ethynediyl) has been prepared by dehydrohalogenation of 1,2-dibromoethylene with an excess of potassium tert-butoxide in 2,3-dimethyl-2-butene as the solvent and the reagent. The major products of this reaction were 2,3-dim
Photochemistry of Hydrogen Bromide-Acetylene Complexes in Solid Krypton
Abrash, Samuel A.,Carr, Celia M.,McMahon, Michael T.,Zehner, Robert W.
, p. 11909 - 11917 (2007/10/02)
Hydrogen-bonded complexes between HBr and acetylene in inert gas matrices were subjected to medium-pressure Hg lamp photolysis at 12 K.For HBr-acetylene, the major product was bromoacetylene, while vinyl bromide was present in trace amounts.When HBr-perdeuterioacetylene and DBr-acetylene complexes were photolyzed, bromoacetylene, deuteriobromoacetylene, and the hydrogen exchange product, DBr(HBr)-C2HD, were the primary products.Partially deuterated vinyl bromides were present in trace amounts.In HBr-perdeuterioacetylene, the only isomer observed was cis-CDBr=CHD.In DBr-acetylene, both cis- and trans-CHBr=CHD were observed.In neither experiment was the 1,1-addition product formed.The results are interpreted in terms of the supramolecule model of complex photochemistry put forth by Abrash and Pimentel.
Halogenation of alkynes and alkynylsilanes
Al-Hassan, Mohammed I.
, p. 183 - 186 (2007/10/02)
Halogenation of alkynes has given 1,2-dihalogenoalkenes in good yields.Bromination of alkynylsilanes has given 1,2-dibromovinylsilanes, and reactions with iodine chloride mainly iodoalkynes.
Preparation and Selected Reactions of 2,3-Bis(bromomethyl)-1,3-butadiene
Gaoni, Yehiel,Sadeh, Shoshana
, p. 870 - 881 (2007/10/02)
2,3-Bis(bromomethyl)-1,3-butadiene (1) was prepared by zinc-induced debromination of 1,4-dibromo-2,3-bis(bromomethyl)-2-butene (2).The versatility of 1 as a synthetic intermediate was demonstrated through consecutive use of its allylic bromides and conjugated diene functions, with eventual further modification of the primary reaction products.Coupling of 1 with vinylmagnesium chloride or ethynylmagnesium bromide gave highly unsaturated hydrocarbons (8-11).Reaction of 1 with nucleophiles such as sodium methoxide, sodium azide, sodium acetate, or potassium cyanide gave symmetrically disubstituted 1,3-butadienes ( 12a-d) which could in some cases be modified at the level of the substituent into other analogous dienes (12e-f).Five-membered heterocycles with exocyclic cis-fixed dienes, namely, the thiolane 13, oxolane 14, and pyrrolidines 15a-e were obtained from 1 by reaction with sodium sulfide, with potassium hydroxide, or with secondary amines, respectively.Two of the pyrrolidines (15a,c) were photolytically cyclized into the corresponding 3-azabicycloheptene derivatives (24a,b).Dimethylenehexahydropyridazine derivatives (28,29) were obtained from 1 by reaction with dimethyl azodicarboxylate and subsequent elimination of bromine.These unstable compounds could be stabilized as diene-iron tricarbonyl complexes (31-34).Carbocyclic systems were obtained from 1 by various Diels-Alder additions, such as the addition of dimethyl acetylenedicarboxylate which was followed by debromination and addition of a second molecule of the acetylenic ester to give a tetrahydronaphthalene derivative (35 -> 36 -> 37).Reaction of 1 with diiron nonacarbonyl produced three binuclear ? complexes: the known 2,2'-bis(?-allyl) complex (38) and two isomeric trimethylenemethane-type complexes (39,40) d eriving from dimerization of 1.The structure of the latter was proven by isomerization into bis(diene) complexes (41,42) and oxidation to known hydrocarbons.
Infrared Spectra of Hydrogen-Bonded ? Complexes between Hydrogen Halides and Acetylene
McDonald, Stephen A.,Johnson, Gary L.,Keelan, Brian W.,Andrews, Lester
, p. 2892 - 2896 (2007/10/02)
Hydrogen-bonded ? complexes C2H2--H-X have been formed by codeposition of C2H2 and HX in excess argon at 15 K and by vacuum-UV photolysis of vinyl halides.The strength of the hydrogen bond, as measured by the displacement of the H-X vibrational fundamental below the isolated HX value, decreases in the series HF, HCl, and HBr as expected.Similar complexes made from di- and thichloroethylenes give slightly higher H-Cl vibrations which show minimal interaction between the halide and the acetylene substituent.The H-F fundamentals for C2H4 and C2H2 complexes at 3732 and 3747 cm-1, respectively, show that the ? electrons in double and triple bonds are comparable hydrogen-bond acceptors.
