775-24-6Relevant academic research and scientific papers
Catalytic synthesis of n-alkyl arenes through alkyl group cross-metathesis
Dobereiner, Graham E.,Yuan, Jian,Schrock, Richard R.,Goldman, Alan S.,Hackenberg, Jason D.
, p. 12572 - 12575 (2013/09/23)
n-Alkyl arenes were prepared in a one-pot tandem dehydrogenation/olefin metathesis/hydrogenation sequence directly from alkanes and ethylbenzene. Excellent selectivity was observed when (tBuPCP)IrH2 was paired with tungsten monoaryloxide pyrrolide complexes such as W(NAr)(C 3H6)(pyr)(OHIPT) (1a) [Ar = 2,6-i-Pr2C 6H3; pyr = pyrrolide; OHIPT = 2,6-(2,4,6-i-Pr 3C6H2)2C6H3O]. Complex 1a was also especially active in n-octane self-metathesis, providing the highest product concentrations reported to date. The thermal stability of selected olefin metathesis catalysts allowed elevated temperatures and extended reaction times to be employed.
Rhodium-catalyzed silylation and intramolecular arylation of nitriles via the silicon-assisted cleavage of carbon-cyano bonds
Tobisu, Mamoru,Kita, Yusuke,Ano, Yusuke,Chatani, Naoto
supporting information; experimental part, p. 15982 - 15989 (2009/05/16)
A rhodium-catalyzed silylation reaction of carbon - cyano bonds using disilane has been developed. Under these catalytic conditions, carbon-cyano bonds in aryl, alkenyl, allyl, and benzyl cyanides bearing a variety of functional groups can be silylated. The observation of an enamine side product in the silylation of benzyl cyanides and related stoichiometric studies indicate that the carbon-cyano bond cleavage proceeds through the deinsertion of silyl isocyanide from η2-iminoacyl complex B. Knowledge gained from these studies has led to the development of a new intramolecular biaryl coupling reaction in which aryl cyanides and aryl chlorides are cross-coupled.
CHARGE-TRANSFER COMPLEXES IN THE REACTION OF BENZYL BROMIDE WITH VINYLTRIMETHYLSILANE INITIATED WITH AN Fe(CO)5-CHIRAL COCATALYST SYSTEM
Balabanova, L. V.,Terent'ev, A. B.,Vasil'eva, T. T.,Gapusenko, S. I.,Churkina, T. D.
, p. 1574 - 1575 (2007/10/02)
Addition of benzyl bromide to vinyltrimethylsilane by a radical mechanism in the presence of Fe(CO)5-(L)-N-benzoyl-2-methoxycarbonylpyrrolidone was performed.Formation of a complex with a charge-transfer band of high intensity was shown to occur by means of UV spectroscopy on the basis of characteristics of the charge-transfer complexes.
Study of the mechanism of the addition of benzyl bromide to trimethylvinylsilane in the presence of the Fe(CO)5-DMF system
Terent'ev, A. B.,Gapusenko, S. I.,Vasil'eva, T. T.
, p. 1352 - 1356 (2007/10/02)
The general kinetics of the addition of benzyl bromide to trimethylvinylsilane in the presence of the Fe(CO)5-DMF system has been studied.The reaction orders with respect to each reagent found in the study corresponding to a radical chain mechanism of the process.The metal-complex system takes part only in the initiation stage and only at a strictly defined ratio of the components. - Key words: benzyl bromide, trimethylvinylsilane, addition; radicals; metal-complex initiation; kinetics; mechanism.
Radical-type addition of benzyl bromide to vinyl chloride: the kinetics and activation energy of the process
Vasil'eva, T. T.,Gapusenko, S. I.,Terent'ev, A. B.,Pinyaskin, V. V.,Stankevich, I. V.,et al.
, p. 840 - 842 (2007/10/02)
Radical telomerization of vinyl chloride with benzyl bromide and the competitive reaction of benzyl bromide with vinyl chloride and trimethylvinylsilane have been studied.The relative rate constant for the addition of C6H5C(*)H2 to vinyl chloride, krel (with respect to trimethylvinylsilane), is close to unity, whereas the activation energy of the addition of C6H5C(*)H2 to vinyl chloride is considerably lower (by 7 kcal mol-1) than in the reaction involving trimethylvinylsilane.The possible fragmentation of the radical-adduct C6H5CH2CH2C(*)HCl was suggested as one of the possible reasons of underestimation of krelCl.The activation energy was estimated by the MPDO/3 method.
HOMOLYTIC ADDITION OF BENZYL BROMIDE TO UNSATURATED COMPOUNDS IN CONDITIONS OF METAL-COMPLEX INITIATION
Vasil'eva, T. T.,Gapusenko, S. I.,Vitt, S. V.,Terent'ev, A. B.
, p. 1841 - 1845 (2007/10/02)
Radical addition of benzyl bromide to unsaturated compounds containing substituents of a different polar nature, CH2=CHX (X = C4H9, SiMe3, CF3, CO2Me, CN, H), was conducted in the presence of the Fe(CO)5 + DMF (HMPA) system.Adducts were obtained and their structure was demonstrated by 13C NMR and mass spectrometry.Keywords: homolytic addition, benzyl bromide, unsaturated compounds, iron pentacarbonyl, DMF, HMPA.
Carbanion Rearrangements of ω-Phenyl-ω-(trimethylsilyl)alkyllithium Compounds: Intramolecular Reactions of Benzyltrimethylsilanes with a Carbon-Lithium Bond
Maercker, Adalbert,Stoetzel, Reinhard
, p. 1695 - 1706 (2007/10/02)
ω-Phenyl-ω-(trimethylsilyl)alkyllithium compounds show four out of five theoretically conceivable possibilities for intramolecular stabilization depending on the solvent and on the chain length n.While transmetalation of a methyl group at the silicon atom by a 1,(n+2) proton transfer is observed in any case, the intramolecular 1,n shift of the benzylic proton does only take place with n >/= 4.The main reaction, however for n = 3 and 4 only, is represented by the 1,n trimethylsilyl shift via a cyclic ate complex as an intermediate which partly splits off methyllithium yielding the corresponding silacycloalkane derivatives.In going from diethyl ether to THF as the solvent, the silyl shifts are more accelerated than the proton shifts.In no case, however, a Grovenstein-Zimmermann rearrangement involving phenyl migration took place.Degenerate silyl shifts starting from α-deuterated ω-(trimethylsilyl)alkyllithium compounds could not be detected either.Only by introduction of a second trimethylsilyl group into the 3 position a 1,3-(C -> C)-trimethylsilyl shift is initiated again.
Carbanion Rearrangements by Intramolecular 1,ω Proton Shifts, III. The Reaction of 2-, 3-, 4-, and 5-Phenylalkyllithium Compounds
Maercker, Adalbert,Passlack, Michael
, p. 540 - 577 (2007/10/02)
Upon addition of THF to a solution of 4-phenylbutyllithium (2) in diethyl ether a rapid intramolecular 1,4 proton shift takes place with the formation of 1-phenylbutyllithium (5).Similarly, although somewhat more slowly, 5-phenylpentyllithium (82) rearranges to 1-phenylpentyllithium (83) via 1,5 proton transfer.The corresponding rearrangements by 1,2 or 1,3 hydrogen shifts, however, starting with 2-phenylethyllithium (1) and 3-phenylpropyllithium (54), respectively, were not detected.With 3-phenylpropyllithium (54) a slow intramolecular 1,5 transfer an ortho proton is observed instead, yielding o-propylphenyllithium (100).The corresponding 1,6 shift with 4-phenylbutyllithium (2) was also detected in a minor amount in addition to the 1,4 proton shift already mentioned.There is no indication, however, for a 1,4 transfer of an ortho proton in 2-phenylethyllithium (1).The reaction products in this case can be exclusively explained by intermolecular transmetallation reactions.All ω-phenylalkyllithium compounds under investigation show interesting side and secondary reactions being rather different in deuterated solvents and in deuteriumfree solvents, respectively, due to the isotope effects.The analysis of the products is accomplished by 1H-NMR spectroscopy and, after derivatization, with the help of a GC-MS-combination.Stereoelectronic reasons are made responsible for the failure of the intramolecular 1,2 and 1,3 proton shift in these systems.
