4412-39-9Relevant academic research and scientific papers
One-pot, oxidative and selective conversion of benzylic silyl and tetrahydropyranyl ethers to gem-dichlorides using trichloroisocyanuric acid and triphenylphosphine as an efficient and neutral system
Khadem Moghaddam, Roqayeh,Aghapour, Ghasem
, p. 398 - 406 (2020/11/19)
A one-pot and oxidative method is described for the first time for the conversion of benzylic trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers to gem-dichlorides using trichloroisocyanuric acid (TCCA) and triphenylphosphine (PPh3) in neutral media. Various theses substrates containing electron withdrawing or donating groups can be efficiently converted to their corresponding gem-dichlorides in good to excellent yields. The present method shows a high degree of chemoselectivity, and due to its one-pot nature is in accordance with green chemistry.
A mild synthesis of vinyl halides and gem-dihalides using triphenyl phosphite-halogen-based reagents
Spaggiari, Alberto,Vaccari, Daniele,Davoli, Paolo,Torre, Giovanni,Prati, Fabio
, p. 2216 - 2219 (2007/10/03)
A new application of (PhO)3P-halogen-based reagents to the synthesis of vinyl halides and gem-dihalides is described. Vinyl halides were prepared in good to excellent yields from enolizable ketones, whereas aldehydes afforded the corresponding gem-dihalides. The halogenation proceeded smoothly under mild conditions.
Benzylchlorocarbene: Origins of Arrhenius Curvature in the Kinetics of the 1,2-H Shift Rearrangement
Merrer, Dina C.,Moss, Robert A.,Liu, Michael T.H.,Banks,Ingold, Keith U.
, p. 3010 - 3016 (2007/10/03)
Benzylchlorocarbene (1, BCC) was generated photochemically from benzylchlorodiazirine (2) in isooctane, methylcyclohexane (MCH), and tetrachloroethane (TCE) at temperatures from ～30 to -75°C. At -70°C in isooctane, the identified products included Z/E-β-chlorostyrenes 4 (46.6%), α-chlorostyrene 5 (2.4%), l,1-dichloro-2-phenylethane 6 (1.9%), a BCC-isooctane insertion product 8 (5.5%), carbene dimers 9 (3.8%), and azine 3 (30%). The significant incursion of intermolecular products 3, 8, and 9 implies that laser flash photolytic (LFP) kinetic data for the decay of BCC obtained at low temperature is biased and should not be employed in Arrhenius analyses. Accordingly, previously obtained curved Arrhenius correlations for BCC do not necessarily implicate , quantum mechanical tunneling (QMT) in the 1,2-H shift rearrangement of BCC to 4. Similarly in MCH, where BCC affords a solvent insertion product in ～44-53% yield, the curved Arrhenius correlation (Figure 1) cannot be readily interpreted. In polar solvents such as TCE, clean H-shift reactions of BCC are obtained even at -71°C; an Arrhenius correlation of LFP kinetic data is linear from 3 to -71°C (Figure 2), affording Ea = 3.2 kcal mol-1 and log A = 10.0 s-1. Therefore, QMT does not appear to play a major role in the 1,2-H shift rearrangement of BCC at ambient or near ambient temperature in solution.
THIOCYANOARYLATION OF VINYL AND VINYLIDENE CHLORIDES
Grishchuk, B. D.,Gorbovoi, P. M.,Kudrik, E. Ya.,Ganushchak, N. I
, p. 2396 - 2401 (2007/10/02)
A method was developed for the preparation of chlorine-containing aliphatic-aromatic thicyanates (1-chloro- and 1,1-dichloro-1-thiocyanato-2-arylethanes) by reactions of arenediazonium tetrafluoroborates with vinyl chloride and with vinylidene chloride in presence of potassium (sodium or ammonium) thocyanate.A necessary condition for success in the reaction is the presence of a catalyst: Cu(II) or Fe(II) thicyanate.
Alkylations of Trichloromethylketones Effected by Trichloroacetate and a Complex Consecutive Reaction
Dehmlow, Eckehard V.,Raths, Hans-Christian
, p. 918 - 920 (2007/10/02)
A phase transfer reaction between the title ketones, sodium trichloroacetate, and an alkyl halide leads to 2a, b, 4, or 5.Whereas these compounds are fragmented by NaOH, sodium methoxide/methylmalonate/methanol give compound 8 from 5 in a complex series of consecutive rearrangements. - Key words: Trichloromethylketones, Phase Transfer Reaction
Electrochemical Cross-Coupling of Alkyl Halides in the Presence of a Sacrificial Anode
Nedelec, Jean-Yves,Mouloud, Hassan Ait Haddou,Folest, Jean-Claude,Perichon, Jacques
, p. 4720 - 4724 (2007/10/02)
The electrochemical trichloromethylation of various alkyl halides has been obtained in high yields in an undivided cell in the presence of a sacrificial anode.This cross-coupling process has been extended to the preparation of numerous gem-dichloro compounds from trichloro-substituted methanes and alkyl halides.Zinc,magnesium or aluminium were used as anodes according to the reduction potentiel of the reagents.Mixtures of polar aprotic solvents,e.g.THF-TMU or THF-NMP, were found more appropriate than pure solvents.The critical role of the metallic ions from the consumption of the anode has been clearly evidenced.
Effect of Diazirine Concentration on the Reaction of 3-Benzyl-3-chlorodiazirine with Methanol
Liu, Michael T. H.,Subramanian, Ramasamy
, p. 15 - 18 (2007/10/02)
In the reation of 3-chloro-3-benzyldiazirine with methanol, the concentration of diazirine has pronounced effects on the acetal/chlorostyrene product ratio.A mechanism is proposed to account for these results.
Synthesis of 1,1-Dihaloalkanes
Garcia Martinez, A.,Herrera Fernandez, A.,Martinez Alvarez, R.,Garcia Fraile, A.,Bueno Calderon, J.,et al.
, p. 1076 - 1078 (2007/10/02)
The reaction of 1,1-bistrifluoromethylsulfonyloxy-alkanes (2) with magnesium iodide in carbon disulphide at O deg C affords 1,1-diiodoalkanes (3-I) in good yields.No rearrangement products are observed.The reaction of 2 with magnesium bromide in carbon disulphide or titanium tetrachloride in dichloromethane yields either 1,1-dichloro- (3-Cl) or 1,1-dibromoalkanes (3-Br).Rearrangements products are formed from α-branched substrates.
