1120-36-1Relevant academic research and scientific papers
Fluorination of secondary and primary alcohols by thermal decomposition of electrochemically generated alkoxy triphenylphosphonium tetrafluoroborates
Maeda, Hatsuo,Koide, Takashi,Matsumoto, Sayaka,Ohmori, Hidenobu
, p. 1480 - 1483 (1996)
Replacement of hydroxyl groups in secondary and primary alcohols (1) with a fluorine atom arising from tetrafluoroborate anion has been performed by the electrochemical formation of alkoxy triphenylphosphonium tetrafluoroborates (2) from 1, followed by their thermal decomposition. The procedure is quite simple, involving: (1) constant-current electrolysis of a mixture of 1, Ph3P, and Ph3PH·BF4 in CH2Cl2 in an undivided cell; (2) refluxing a tetrahydrofuran or dioxane solution of the residue afforded by evaporation of the solvent in vacuo after the electrolysis. Cyclic secondary alcohols such as 3β-hydroxy steroids and 2-adamantanol are transformed into the corresponding fluorides in satisfactory yields when the geometry of the leaving group in 2 is suitable for the substitution or an elimination process for 2 to give an alkene is stereochemically forbidden. The fluorination of steroidal alcohols and 4-phenyl-1-cyclohexanol proceeded with complete inversion, demonstrating that a fluorine atom from the tetrafluoroborate anion attacks from the side opposite to the phosphonium moiety in 2 via an SN2 mechanism rather than an SN1 mechanism. The fluorination of acyclic secondary and primary alcohols was performed by the present method in reasonable yields, although the reaction for the latter required more forcing conditions, such as refluxing in dioxane.
Approximate rate constants for the addition of alkyl radicals to allylstannanes
Curran,Van Elburg
, p. 2861 - 2864 (1990)
Rate constants for the addition of alkyl radicals to allylstannanes lie in the range of 104-105 M-1 s-1 at 50-80°C.
Synergistic sex pheromone components of white-spotted tussock moth, Orgyia thyellina
Gries, Gerhard,Clearwater, John,Gries, Regine,Khaskin, Grigori,King, Skip,Schaefer, Paul
, p. 1091 - 1104 (1999)
In 1996, the exotic white-spotted tussock moth (WSTM), Orgyia thyellina (Lepidoptera: Lymantriidae), was discovered in Auckland, New Zealand. Because establishment of WSTM would threaten New Zealand's orchard industry and international trade, eradication of WSTM with microbial insecticide was initiated. To monitor and complement eradication of WSTM by capture of male moths in pheromone-baited traps, pheromone components of female WSTM needed to be identified. Coupled gas chromatographic-electroantennographic detection analysis of pheromone gland extract revealed several compounds that elicited responses from male moth antennae. Mass spectra of the two most EAD-active compounds suggested, and comparative GC-MS of authentic standards confirmed, that they were (Z)-6-heneicosen-11-one (Z6-11-one) and (Z)-6-heneicosen-9- one, the latter termed here 'thyellinone.' In field experiments in Japan, Z6- 11-one plus thyellinone at a 100:5 ratio attracted WSTM males, whereas either ketone alone failed to attract a single male moth. Addition of further candidate pheromone components did not enhance attractiveness of the binary blend. Through the 1997-1998 summer, 45,000 commercial trap lures baited with 2000 μg of Z6-11-one and 100 μg of thyellinone were deployed in Auckland towards eradication of the residual WSTM population.
SELECTIVE MIXED COUPLING OF CARBOXYLIC ACIDS-III. SYNTHESIS OF CYCLOPENTADECANONE FROM CYCLIC TETRAACYL DIPEROXIDES
Feldhues, Michael,Schafer, Hans. J.
, p. 1285 - 1290 (1986)
Cyclopentadecanone (1b) and cyclotetradecane (1a) were prepared in 53 and 83percent yield by thermolysis or photolysis of the cyclic tetraacyl diperoxides 4b and 4a.The compounds 4a, b were obtained from diperoxydodecanedioic acid (3) and the acyl chloride 5a or the dicarboxylic acid 2b.
Iron-catalyzed cross-coupling of alkenyl sulfides with grignard reagents
Itami, Kenichiro,Higashi, Shohei,Mineno, Masahiro,Yoshida, Jun-Ichi
, p. 1219 - 1222 (2005)
(Chemical Equation Presented) The iron-catalyzed cross-coupling reaction of alkenyl sulfides with Grignard reagents is described. While the cross-coupling proceeds efficiently at alkenyl-S bonds, almost no cross-coupling takes place at aryl-S bonds, attesting to a unique selectivity of iron catalysis. The beneficial effect of potentially coordinating 2-pyrimidyl group on sulfur is also described.
Reduction of fatty acid methyl esters to fatty alcohols to improve volatility for isotopic analysis without extraneous carbon.
Corso,Lewis,Brenna
, p. 3752 - 3756 (1998)
Carbon in derivatization groups cannot be distinguished from analyte carbon by chromatography-based high-precision compound-specific or position-specific isotope analysis. We report the reduction of fatty acid methyl esters to fatty alcohols to facilitate high-quality chromatographic separation, without addition of extraneous carbon, with subsequent high-precision position-specific isotope analysis. Methyl palmitate is quantitatively reduced to 1-hexadecanol by LiAlH4 in a one-step reaction. Gas-phase pyrolysis of 1-hexadecanol results in a series of monounsaturated alcohols and alpha-olefins analogous to fragmentation found for methyl palmitate, as well as an additional peak corresponding to the pyrolytic dehydration product, 1-hexadecene. Carbon isotope analysis of the fragments yielded precision of SD (delta 13C) 0.4/1000. Results of position-specific analysis of very low enrichment [1-13C]-1-hexadecanol (delta 13C = -4.00/1000) showed no evidence of scrambling of the C1 position, and isotope ratios in accord with expectations. The pyrolysis product 1-hexadecene was isotopically enriched relative to 1-hexadecanol, which may cause minor depletion of other pyrolysis products that can be taken into account by routine calibration. The procedure is general and can be extended to compound-specific and position-specific analysis of moderate molecular weight, low-volatility analytes containing acid groups that would otherwise be blocked with methyl, ethyl, acetyl, or trimethyl silyl groups containing extraneous carbon.
A catalytic application of Co/Zr heterobimetallic complexes: Kumada coupling of unactivated alkyl halides with alkyl grignard reagents
Zhou, Wen,Napoline, Jonathan Wesley,Thomas, Christine M.
, p. 2029 - 2033 (2011)
Tris(phosphanylamide) early/late heterobimetallic Zr/Co complexes, ClZr(R′NPR2)3CoI [R′ = iPr, R = Ph (1), R′ = 2,4,6-trimethylphenyl, R = iPr (2), R′ = R = iPr (3)], have been utilized as catalysts for the cross-coupling of alkyl halides with n-octylmagnesium bromide. While yields are consistently higher for alkyl bromide substrates, it is found that these unusual heterobimetallic complexes are also active towards more challenging alkyl chloride substrates. This is particularly interesting in light of the fact that monometallic cobalt complexes are inert towards these substrates, suggesting that Zr also plays a role in catalysis. Radical trapping studies suggest that a one-electron transfer radical oxidative addition pathway is operative.
REDUCTION OF THIIRANES TO ALKENES AND ALKANES
Schauder, J.R.,Denis, J.N.,Krief, A.
, p. 1657 - 1660 (1983)
Various reagents were tested in order to reduce thiiranes to alkanes or olefins.The results of this investigation is presented in this letter.
Efficient iridium-catalyzed decarbonylation reaction of aliphatic carboxylic acids leading to internal or terminal alkenes
Maetani, Shinji,Fukuyama, Takahide,Suzuki, Nobuyoshi,Ishihara, Daisuke,Ryu, Ilhyong
, p. 1389 - 1394 (2011)
Vaska's complex, IrCl(CO)(PPh3)2, when combined with KI as an additive, served as an excellent catalyst for the decarbonylation of long-chain aliphatic carboxylic acids to give internal alkenes with high selectivity. On combination with KI and Ac2O as additives under controlled temperatures, decarbonylation proceeded to give terminal alkenes with high selectivity.
Contra-thermodynamic Olefin Isomerization by Chain-Walking Hydroboration and Dehydroboration
Bloomer, Brandon,Butcher, Trevor W.,Ciccia, Nicodemo R.,Conk, Richard J.,Hanna, Steven,Hartwig, John F.
supporting information, p. 1005 - 1010 (2022/02/10)
We report a dehydroboration process that can be coupled with chain-walking hydroboration to create a one-pot, contra-thermodynamic, short-or long-range isomerization of internal olefins to terminal olefins. This dehydroboration occurs by a sequence comprising activation with a nucleophile, iodination, and base-promoted elimination. The isomerization proceeds at room temperature without the need for a fluoride base, and the substrate scope of this isomerization is expanded over those of previous isomerizations we have reported with silanes.
