In rat liver cytosol meso-2,3-dibromobutane was converted, almost exclusively, into trans-2-butene while racemic-2,3-dibromobutane gave rise to cis-2-butene.
IDENTIFICATION AND USE: 2-Butene is a colorless gas. It is used as a solvent and a cross-linking agent. It is also used to polymerize gasoline, and for butadiene synthesis, as well as the synthesis of derivatives. HUMAN STUDIES: 2-Butene is an asphyxiant gas. Rapid evaporation of liquid 2-butene may cause frostbite. it may cause effects on the CNS. Exposure may result in unconsciousness. ANIMAL STUDIES: Rats were exposed for 4 hr to 2-butene at a nominal concentration of 10,000 ppm (22,948 mg/cu m). No clinical signs were seen and normal growth occurred over the 14 d observation period. 2-Butene is a cardiac sensitizer in dogs. In developmental studies in rats, there were no effects on mating behavior, fertility and gestation indices, the number of implantation sites and corpora lutea per dam, numbers of pups delivered, viability of pups at and after birth and the pup sex ratio when compared to the control group. There were no treatment-related effects on the development of pups. Male and female rats were exposed to 2-butene at target concentrations of 2500 or 5000 ppm (5737 or 11,474 mg/cu m) for two weeks prior to breeding, during breeding (1 week) and until day 19 of gestation (39-46 days of exposure). No significant systemic toxicity occurred in either sex, or in pregnant female rats. 2-Butene is a CNS depressant. About 13 to 13.5% (300 or 400 mg/L) causes deep CNS depression, and in mice about 19% (120 to 420 mg/L) is fatal. It is a mild mucous membrane irritant. A chromosome aberration study was conducted with 2-butene in rat lymphocytes in vito. No significant increases were seen in the frequency of chromosome aberrations either in the presence or absence of a metabolic activation. 2-Butene was not mutagenic to S. typhimurium TA98, TA100, TA1535, TA 1537 and E.coli WP2uvrA, with or without metabolic activation.
IDENTIFICATION AND USE: trans-2-Butene is a colorless gas. It is used as a solvent, as a cross-linking agent, in the polymerization of gasoline, and in butadiene synthesis. It is also used in the synthesis of C4 and C5 derivatives. HUMAN STUDIES: trans-2-Butene is a simple asphyxiant. Rapid evaporation of liquid 2-butene (in its cis or trans form, or as a mixture of both) may cause frostbite. The substance may cause effects on the central nervous system. Exposure may result in unconsciousness. ANIMAL STUDIES: There are no data available.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
暴露途径
暴露主要通过吸入发生。
Exposure mainly occurs via inhalation.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
吸入症状
晕眩。失去意识。窒息。
Dizziness. Unconsciousness. Suffocation.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
皮肤症状
接触液体时:冻伤。
ON CONTACT WITH LIQUID: FROSTBITE.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
Mechanistic Interrogation of Alkyne Hydroarylations Catalyzed by Highly Reduced, Single-Component Cobalt Complexes
作者:Benjamin A. Suslick、T. Don Tilley
DOI:10.1021/jacs.0c04072
日期:2020.6.24
complexes. Studies of the stoichiometric reaction of Co(I) or Co(II) precursors with CyMgCl implicated catalyst initiation via a β-H elimination/deprotonation pathway. The resulting single-component Co(-I) complex is proposed as the direct precatalyst. Michaelis-Menten enzyme kineticstudies provide mechanistic details regarding the catalytic dependence on substrate. The (N-aryl)aryl ethanimine substrate
Flash vacuum pyrolysis over magnesium. Part 1. Pyrolysis of benzylic, other aryl/alkyl and aliphatic halides
作者:R. Alan Aitken、Philip K. G. Hodgson、John J. Morrison、Adebayo O. Oyewale
DOI:10.1039/b108663d
日期:2002.1.23
Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides
there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E,E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do
not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.
A short convergent synthesis of the [3.2.1]dioxabicyclooctane subunit of sorangicin A via regioselective epoxide opening
作者:Sadagopan Raghavan、Satyanarayana Nyalata
DOI:10.1016/j.tet.2018.01.036
日期:2018.3
In this paper, we disclose the synthesis of the dioxabicyclo[3.2.1]octane subunit of the potent antibiotic sorangicin A. The synthesis was achieved in a convergent manner in 8 steps. Regio- and stereoselective intermolecular epoxide opening, ring-closing metathesis and iodo-etherification are key steps. cis-2-Butene diol has been employed as a common staring material.
Controlled Reduction of Nitriles by Sodium Hydride and Zinc Chloride
作者:Shunsuke Chiba、Derek Yiren Ong
DOI:10.1055/s-0039-1690838
日期:2020.5
new protocol for the controlled reduction of nitriles to aldehydes was developed using a combination of sodium hydride and zinc chloride. The iminyl zinc intermediatesderivedfrom aromatic nitriles could be further functionalized with allylmetal nucleophiles to afford homoallylamines. As the method allows the reduction of various aliphatic and aromatic nitriles with a concise procedure under milder
Rearrangement of allyl hexafluoroisopropyl sulfides [1]
作者:Donald J. Burton、Yoshio Inouye
DOI:10.1016/s0022-1139(00)82663-9
日期:1981.10
terminal allylic hexafluoroisopropyl sulfides to the internal olefinic sulfide occurs under either photochemical or thermal conditions. In the case of the formation of E and Z isomers, the E isomer was predominant. The rearrangement is suggested as a unimolecular, associative radical mechanism, via kineticstudies, use of inhibitors, or radical initiator.