109431-72-3Relevant articles and documents
Cobalt Catalysed Allylic and Benzylic Oxidations with Dioxygen in the Presence of Ethyl 2-oxocyclopentanecarboxylate
Punniyamurthy, T.,Iqbal, Javed
, p. 4003 - 4006 (1994)
An efficient allylic and benzylic oxidation of various cyclic alkenes and benzylic compounds respectively can be achieved with dioxygen in the presence of ethyl 2-oxocyclopentanecarboxylate 2 and catalytic amount of cobalt(II) Schiff's base complex 1.
Synthesis of C-5'-nor-dideoxycarbanucleosides structurally related to neplanocin C
Comin, Maria J.,Pujol, Carlos A.,Damonte, Elsa B.,Rodriguez, Juan B.
, p. 2219 - 2231 (1999)
Purine carbanucleosides built on a 6-oxabicyclo[3.1.0]hexane template were synthesized from readily available 2-cyclopentenone employing a Mitsunobu reaction to incorporate the base onto the carbocyclic ring. Both adenosine and guanosine analogues exhibited moderate antiviral activity.
Hill,Edwards
, p. 3239,3240 (1964)
Liquid-phase epoxidation of alkenes using molecular oxygen catalyzed by vanadium cation-exchanged montmorillonite
Mitsudome, Takato,Nosaka, Naoya,Mori, Kohsuke,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 1626 - 1627 (2005)
Vanadium cation-exchanged montmorillonite can efficiently catalyze the selective epoxidation of various alkenes and the oxygenation of adamantane using molecular oxygen as a sole oxidant. Copyright
Facile isomerization of oxiranes to allyl alcohols by mixed metal bases
Mordini, Alessandro,Rayana, Ezzedine Ben,Margot, Christian,Schlosser, Manfred
, p. 2401 - 2410 (1990)
The mixture of lithium diisopropylamide and potassium tert-butoxide ("LIDAKOR reagent") promotes smooth ring opening of oxiranes to afford allyl alcohols with good to excellent yields. Internal epoxyalkanes and large size epoxy-cycloalkanes give preferentially or exclusively trans-alkenols. The regio- and stereochemistry of the ring opening reaction are essentially the consequence of syn-periplanar elimination mechanisms.
Reductive alkylation of β-alkoxy aziridines: New route to substituted allylic amines
Rosser, Clare M.,Coole, Susannah C.,Kirby, Jonathan P.,O'Brien, Peter,Caine, Darren
, p. 4817 - 4819 (2004)
(Chemical Equation Presented) A new route to substituted cyclic allylic amines via the reductive alkylation of β-alkoxy aziridines using excess alkyllithium reagents is described.
Highly active delaminated Ti-MWW for epoxidation of bulky cycloalkenes with hydrogen peroxide
Nuntasri, Duangamol,Wu, Peng,Tatsumi, Takashi
, p. 326 - 327 (2003)
A novel titanosilicate, prepared by the partial delamination of acid-treated Ti-MWW, possesses an extremely high specific surface area and proves to be a selective and active liquid-phase oxidation catalyst for bulky alkenes.
OAc AS A HOMOGENEOUS CATALYST FOR SELECTIVE ENONE FORMATION BY ALLYLIC OXIDATION OF OLEFINS
Uemura, Sakae,Patil, Suresh R.
, p. 4353 - 4356 (1982)
Treatment of several cyclic olefins and allylbenzene with a catalytic amount of OAc in acetic acid in the presence of t-butyl hydroperoxide affords the corresponding α,β-unsaturated carbonyl compounds(enones) highly selectively via an ionic pathway.
An experimental and computational study of 1,2-hydrogen migrations in 2-hydroxycyclopentylidene and its conjugate base
Morgan,O'Connor,Humphrey,Buschman
, p. 1600 - 1606 (2001)
Thermal decomposition of α-hydroxydiazirine 2 gives primarily cyclopentanone and some allylic alcohol, in similar amounts as the known cyclohexyl analogue 1. Calculations (B3LYP/6-31+G*) also show cyclopentanone to be the major product of this carbene rearrangement. Diazirine 2 and the lithium salt of the corresponding conjugate base 3 were decomposed by photolysis. The proportion of ketone formed increases with deprotonation, a trend also found computationally. In comparison, the base-induced isomerization of cyclopentene oxide, which proceeds via α-elimination to a carbenoid intermediate similar to that obtained from 3, yields primarily allylic alcohol rather than ketone; neither ring size nor charge thus accounts for the unusual product distribution observed. Interestingly, the calculations reveal that in the gas phase with no counterion, the singlet, oxyanionic carbene, and the α-deprotonated epoxide are the same, rather than discrete structures. This intramolecular complexation stablilizes the oxyanionic carbene by 20-25 kcal/mol.
Pd-catalyzed regioselective C?H alkenylation and alkynylation of allylic alcohols with the assistance of a bidentate phenanthroline auxiliary
Hirano, Koji,Miura, Masahiro,Xu, Shibo
, p. 9059 - 9064 (2020)
A Pd-catalyzed regioselective C?H alkenylation of allylic alcohols with electron-deficient alkenes has been developed. The key to success is the introduction of bidentately coordinating phenanthroline directing group, which enables the otherwise challenging and regioselective C?H activation at the proximal alkenyl C?H bonds over the conceivably competitive allylic C?O bond activation. The same Pd/phenanthroline system is efficient for the C?H alkynylation of allylic alcohols with alkynyl bromides.
A study of the aluminum hydride reduction of unsaturated cyclic epoxides
Healy, Eamonn F.,Lewis,Minniear, Amy B.
, p. 6647 - 6648 (1994)
The aluminum hydride reduction of 3,4-epoxycyclopentene to 3-cyclopentenol has been previously observed1 and the complete regiospecificity of the reaction is confirmed here. A mechanism is proposed involving initial complexation of the aluminum hydride anion with the double bond followed by hydride transfer to the 3-Carbon. Analysis of the atomic charges determined from semiempirical electrostaic potentials support the proposed mechanism. Spectroscopic analysis of the resultant alcohol indicates the presence of an O-H''''''π intramolecular hydrogen bonded interaction.
Eco-friendly stereoselective reduction of α,β-unsaturated carbonyl compounds by Er(OTf)3/NaBH4 in 2-MeTHF
Nardi, Monica,Sindona, Giovanni,Costanzo, Paola,Oliverio, Manuela,Procopio, Antonio
, p. 1132 - 1135 (2015)
An operationally simple and environmentally benign catalytic procedure has been developed to selectively reduce different α,β-unsaturated ketones. The corresponding allylic alcohols are obtained with high chemo- and diastereoselectivity using Er(OTf)3 and NaBH4 in 2-MeTHF. This protocol reduces the amount of catalyst and NaBH4 needed, compared to classical procedures and the stages of extraction/purification are carried out in aqueous solutions avoiding the use of toxic solvents. Taking into account that Er(OTf)3 can be considered even less toxic than table salt and the 'greenness' of 2-MeTHF as a solvent, the system Er(OTf)3/2-MeTHF can be proposed as a cheap, efficient, and environmentally sustainable reduction system for the synthesis of allylic alcohols.
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Andrews,M.A.,Cheng,C.W.
, p. 4268 (1982)
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Equilibrium constants for dehydration of water adducts of aromatic carbon-carbon double bonds
Dey, Joykrishna,O'Donoghue, AnnMarie C.,More O'Ferrall, Rory A.
, p. 8561 - 8574 (2002)
Equilibrium constants (Kde) are reported for the dehydration of hydrates of benzene, naphthalene, phenanthrene, and anthracene. Free energies of formation of the hydrates (ΔG°f(aq)) are derived by combining free energies of formation of the parent (dihydroaromatic) hydrocarbon with estimates of the increment in free energy (ΔGOH) accompanying replacement of a hydrogen atom of the hydrocarbon by a hydroxyl group. Combining these in turn with free energies of formation of H2O and of the aromatic hydrocarbon products furnishes the desired equilibrium constants, The method depends on the availability of thermodynamic data (i) for the hydrocarbons from which the hydrates are derived by hydroxyl substitution and (ii) for a sufficient range of alcohols to assess the structural dependence of ΔGOH. The data comprise chiefly heats of formation and standard entropies in the gas phase and free energies of transfer from the gas phase to aqueous solution (the latter being derived from vapor pressures and solubilities). They also include experimental measurements of equilibrium constants for dehydration of alcohols, especially cyclic, allylic, and benzylic alcohols. In general ΔGOH depends on whether the alcohol is (a) primary, secondary, or tertiary; (b) allylic or benzylic; and (c) open chain or cyclic. Differences in geminal interactions of the hydroxyl group of the alcohol with α-alkyl and vinyl or phenyl groups account for variations in ΔGOH of 5 kcal mol-1. Weaker variations which arise from β-vinyl/OH or β-phenyl/OH interactions present in the aromatic hydrates but not in experimentally studied analogues are estimated as 1.0 kcal mol-1. Equilibrium constants for dehydration may be expressed as their negative logs (pKde). Reactions yielding the following aliphatic, aromatic, and antiaromatic unsaturated products then have pKde values: +4.8, ethene; +15.0, ethyne; +22.1, cyclopropene; +28.4 cyclobutadiene; -22.2, benzene; -14.6, naphthalene; -9.2, phenanthrene; -7.4, anthracene. Large positive values are associated with formation of strained or antiaromatic double bonds and large negative values with aromatic double bonds. Trends in pKde parallel those of heats of hydrogenation. The results illustrate the usefulness of a substituent treatment for extending the range of currently available free energies of formation. In addition to hydroxyl substituent effects, ΔGOH, values of ΔGπ for substitution of a π-bond in a hydrocarbon are reported.
Precision vinyl acetate/ethylene (VAE) copolymers by ROMP of acetoxy-substituted cyclic alkenes
Zhang, Jihua,Matta, Megan E.,Martinez, Henry,Hillmyer, Marc A.
, p. 2535 - 2543 (2013)
Precision linear vinyl acetate/ethylene (VAE) copolymers containing acetoxy groups on precisely every eighth backbone carbon were synthesized by ring-opening metathesis polymerization (ROMP) of racemic 3-acetoxy cyclooctene (3AcCOE) followed by hydrogenation. The use of enantiomerically pure 3AcCOE resulted in an optically active polyalkenamer that afforded isotactic precision VAE materials after hydrogenation. Both of these VAE polymers are semicrystalline (by differential scanning calorimetry and wide-angle X-ray scattering) due to their high degrees of regioregularity and the isotactic VAE samples exhibited a higher apparent degree of crystallinity and melting point compared to the atactic version. In contrast, analogous linear VAE copolymers derived from ROMP-hydrogenation of racemic 4- or 5-acetoxy cyclooctenes were regio-irregular and completely amorphous. The ROMP-hydrogenation of 3-acetoxy cycloheptene also affords precision linear VAE copolymers with acetoxy groups on every seventh carbon, but this polymer was noncrystalline. Mechanical characterization showed that the precision 3AcCOE-derived VAE samples possess improved mechanical properties compared to the compositionally similar commercial VAE copolymers produced by radical copolymerization.
Ruthenium-p-cymene Complex Side-Wall Covalently Bonded to Carbon Nanotubes as Efficient Hybrid Transfer Hydrogenation Catalyst
Blanco, Matías,Cembellín, Sara,Agnoli, Stefano,Alemán, José
, p. 5156 - 5165 (2021/11/05)
A half-sandwich ruthenium-p-cymene organometallic complex has been immobilized at Single Walled Carbon Nanotubes (SWNT) sidewalls through a stepwise covalent chemistry protocol. The introduction of amino groups by means of diazonium-chemistry protocols leads the grafting at the outer walls of the nanotubes. This hybrid material is active in the transfer hydrogenation of ketones to yield alcohols, using as hydrogen source 2-propanol. SWNT?NH2?Ru presents a broad scope, performing the reaction under aerobic conditions and can be recycled over 9 consecutive reaction runs without losing activity or leaching ruthenium out. Comparison of the activity with related homogeneous catalysts reveals an improved performance due to the covalent bond between the metal and the material, achieving turnover frequencies as high as 192774 h?1.
Effective synthesis of bicyclodienes via palladium-catalyzed asymmetric allylic alkylation and ruthenium-catalyzed cycloisomerization
Havare, Nizam
, p. 1445 - 1462 (2021/01/05)
[n.3.0]Bicycles (n = 3-6) can be synthesized using palladium-catalyzed asymmetric allylic alkylation followed by rutheniumcatalyzedcycloisomerization.Newtypesoftriarylphosphino-1,2-diaminooxazolineligandsshowthesamehighlevelsofenantioselectivity observed with Trost ligand when employed in Pd-catalyzed allylic alkylation reactions. The enyne products of these allylic alkylation reactions were further elaborated using a Ru-catalyzed redox isomerization process, for which a mechanism is proposed.
