765-90-2Relevant academic research and scientific papers
Carbon-13 NMR and IR Spectroscopic Studies on Some 7-Oxabicycloheptanes and -heptenes. n-? Interaction and Hydrogen Bonding
Senda, Yasuhisa,Ohno, Akihiko,Ishiyama, Jun-ichi,Imaizumi, Shin,Kamiyama, Shin-ichi
, p. 613 - 616 (1987)
The 13C NMR spectra of diastereomeric pairs of the title compounds together with some tetrahydrofurans were examined and the chemical shifts were compared with those for the corresponding bicycloheptanes and -heptenes.The intramolecular interaction between the n-orbital of an oxygen atom and the ?-orbital of an olefinic bond was found in 2-methylene-7-oxabicycloheptane.Intramolecular hydrogen bonding between the 7-oxygen and the hydroxyl group occurs in exo-7-oxabicycloheptane-2-methanol.
Environmentally responsible, safe, and chemoselective catalytic hydrogenation of olefins: ppm level Pd catalysis in recyclable water at room temperature
Gallou, Fabrice,Gao, Eugene S.,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
supporting information, p. 6055 - 6061 (2020/10/14)
Textbook catalytic hydrogenations are typically presented as reactions done in organic solvents and oftentimes under varying pressures of hydrogen using specialized equipment. Catalysts new and old are all used under similar conditions that no longer reflect the times. By definition, such reactions are both environmentally irresponsible and dangerous, especially at industrial scales. We now report on a general method for chemoselective and safe hydrogenation of olefins in water using ppm loadings of palladium from commercially available, inexpensive, and recyclable Pd/C, together with hydrogen gas utilized at 1 atmosphere. A variety of alkenes is amenable to reduction, including terminal, highly substituted internal, and variously conjugated arrays. In most cases, only 500 ppm of heterogeneous Pd/C is sufficient, enabled by micellar catalysis used in recyclable water at room temperature. Comparison with several newly introduced catalysts featuring base metals illustrates the superiority of chemistry in water.
Highly stereoselective tandem cyclizations of 5-hexenyllithiums: Preparation of endo-2-substituted bicyclo[2.2.1]heptanes and 3-substituted trans-bicyclo[ 3.3.0] octanes
Bailey, William F.,Khanolkar, Atmaram D.,Gavaskar, Kaustubh V.
, p. 8053 - 8060 (2007/10/02)
Tandem cyclization of diolefinic alkyllithiums, derived from acyclic diolefinic alkyl iodides by low-temperature lithium-iodine exchange, proceeds via two highly stereoselective and totally regiospecific 5-exo-trig ring closures to deliver bicyclic alkyllithiums. Trapping of the organolithium product by addition of an electrophile cleanly affords functionalized bicyclic molecules in good yield. In this way both endo-2-substituted bicyclo[2.2.1]heptanes and 3-substituted trans-bicyclo[3.3.0]octanes have been prepared in isolated yields of 65-80% from the readily available 3-(2-iodoethyl)-1,5-hexadiene (5) and 7-iodo-4-ethenyl-1-heptene (9), respectively. Attempts to effect tandem cyclization of 5,10-undecadienyllithium (11), which would be mediated by a secondary alkyllithium species, were unsuccessful. The results suggest that tandem anionic cyclization provides a convenient route to a variety of bicyclic systems not readily available by other approaches.
Substituent Effects on 1H Chemical Shifts I-Complete 1H Chemical Shift Assignments of Methyl-Substituted Cyclic Systems
Fisher, Julie,Gradwell, Michael J.
, p. 338 - 346 (2007/10/02)
1H chemical shift assignments are presented for 2-methyladamantane, 2-methylnorbornane (endo and exo) and 2-methylnorbornene (endo and exo).Resonance assignment was achieved using a variety of 1D and 2D homo- and heteronuclear (1H-13C)experiments.The methyl group-induced substituent chemical shift (SCS) is derived and the SCS of protons vicinal to this group is discussed.KEY WORDS Norbornanes Norbornenes Adamantanes 1H NMR Substituent chemical shifts
Optical and Neutron Inelastic Scattering Study of 2-Methylnorbornanes
Brunel, Yvon,Coulombeau, Christian,Coulombeau, Christiane,Jobic, Herve
, p. 937 - 943 (2007/10/02)
We have measured the infrared, Raman, and neutron vibrational spectra of the 2-methylnorbornanes with a CH3 or CD3 methyl group in the exo or endo position.A normal coordinate analysis has been carried out.The torsional modes of the methyl group are assigned at 240 and 235 cm-1 for the hydrogenated exo and endo isomers, respectively.The corresponding barrier is 15.2 +/- 0.2 kJ mol-1.The calculated neutron intensities are in good agreement with the experimental data.The frequencies are used for the determination of the thermodynamic contribution to the standard free energy difference.
Kinetics and Equilibria of Chloride Transfer Reactions. Stabilities of Carbocations Based on Chloride and Hydride Transfer Equilibria Measurements
Sharma, R. B.,Sharma, D. K. Sen,Hiraoka, K.,Kebarle, P.
, p. 3747 - 3757 (2007/10/02)
The kinetics of a number of gas-phase chloride transfer reactions R0(1+)+RCl=R0Cl+R(1+) were measured with a pulsed electron high pressure mass spectrometer.Most of the reactions were found to occur near the collision limit, i.e., with rate constants k ca. 10-9 molecules-1 cm3 s-1.However, several reactions were much slower and were exhibiting negative temperature dependence, i.e., decreasing rate with increasing temperature.Hydride and chloride transfer equilibria were determined for various carbocations R(1+) (R=isopropyl, cyclopentyl, tert-butyl, 1-methylcyclopentyl, substituted benzyls, norbornyl, 2-methyl-2-norbornyl, and adamantyl).Excellent agreement with earlier hydride transfer measurements of Solomon, Meot-Ner, and Field were observed.The chloride affinities generally support conclusions based on the hydride transfer data.Discussion of the data in connection with benzyl cation substituent effects, the norbornyl cation stability, and solvent effects on carbocation stability is presented.The data show that the 2-norbornyl cation is unusually stable.Significant differences between carbocation R(1+) stabilities in gas phase and solution are found which suggest that both differential nucleophilic solvent stabilization and differential nonspecific solvation occur in solution.
Stereoselectivity of Ring Closure of Substituted Hex-5-enyl Radicals
Beckwith, Athelstan L. J.,Lawrence, Tony,Serelis, Algirdas K.
, p. 484 - 485 (2007/10/02)
1,5-Ring closure of 1- or 3-substituted hex-5-enyl radicals affords mainly cis-disubstituted cyclic products, whereas 2- or 4-substituted species give mainly trans-products; the significance of this stereoselectivity is demonstrated in the formation of the norbornane system from acyclic precursors.
Reactions over Supported Metal Catalysts. VI.The Effect of Halogen Compounds on Transition Metal Catalysts Supported on Silica or Pumice. Reactions of 3-Methylnortricyclene
Jackson, W. Roy,Nicolson, David M.
, p. 2261 - 2269 (2007/10/02)
The product
