2745-54-2Relevant articles and documents
Chlorination of (Phebox)Ir(mesityl)(OAc) by thionyl chloride
Zhou, Meng,Goldman, Alan S.
, p. 10122 - 10130 (2015)
Pincer (Phebox)Ir(mesityl)(OAc) (2) (Phebox = 3,5-dimethylphenyl-2,6-bis(oxazolinyl)) complex, formed by benzylic C-H activation of mesitylene (1,3,5-trimethylbenzene) using (Phebox)Ir(OAc)2OH2 (1), was treated with thionyl chloride
Electronic Spectra and Electron Affinity of Monomethyl- and Dimethyl-Substituted Benzyl Radicals
Izumida, Tatsuo,Ichikawa, Tsuneki,Yoshida, Hiroshi
, p. 60 - 63 (1980)
Three monomethylbenzyl radicals and five dimethylbenzyl radicals have been authentically generated by the dissociative electron attachment to corresponding methyl-substituted benzyl chlorides in γ-irradiated glassy matrices and studied by the fluorescence spectrophotometric method at 77 K.For the radicals in a polar ethanol matrix where they are free from the chloride counterion, the wavelengths for the O-O bands of the fluorescence spectra and of the fluorescence-excitation spectra (to the third excited state, in 320-330-nm region) have been determined.These results revise the previous assignment of the spectra of 2,4- and 3,4-dimethylbenzyl radicals.In a nonpolar 3-methylhexane matrix, the association of the counterion with the radicals causes the change in vibrational structures, as well as the shifts of the spectra due to the radicals, and the appearance of a charge-transfer band due to the chloride ion-radical pairs.From the transition energies of the CT bands, the electron affinities have been determined for all eight methyl-substituted benzyl radicals with reference to the reported electron affinity of the benzyl radical.These experimental electron affinities are in general agreement with those calculated theoretically within the INDO approximation.It has been also found that the photolysis of substituted and unsubstituted benzyl chlorides at 77 K results in the rupture of a C-H bond as well as a C-Cl bond, so that several isomeric benzyl-type radicals are generated simultaneously.
Mechanism of solvolysis of substituted benzyl chlorides in aqueous ethanol
Denegri, Bernard,Mati?, Mirela,Va?ko, Monika
supporting information, (2021/11/22)
The mechanism of solvolyses of activated ortho-, meta- and para-substituted benzyl chlorides in aqueous ethanol has been studied by using the Hammett-Brown and Yukawa-Tsuno treatments as well as by correlating logarithms of solvolysis rate constants with relative stabilities of corresponding benzyl carbocations in water calculated at the IEFPCM-M06–2X/6-311+G(3df,3pd) level of theory. Benzyl chlorides containing strong conjugative electron-donors in the para-position solvolyze by the SN1 mechanism, whereas other activated benzyl chlorides solvolyze by the SN2 mechanism via loose transition states.
Benzylation of Arenes with Benzyl Halides under Promoter-Free and Additive-Free Conditions
Cheng, Xinqiang,Shan, Jiankai,Tian, Xinshe,Ren, Yun-Lai,Zhu, Yanyan
, p. 4404 - 4410 (2019/07/03)
It was found that benzyl chlorides and bromides could directly react with electron-rich arenes, which provided an example of promoter-free and additive-free benzylation of arenes. A variety of benzyl chlorides and bromides were treated with benzene rings to give the targeted products in low to high yields. The present conditions tolerated the vinyl group of the substrates. Preliminary mechanistic investigation suggests that the present reactions possibly proceed via an autocatalytic mechanism pathway.
Improved Halogenation of Methyl Aromatics and Methyl Heteroaromatics: Unexpected Reactivity of Tetrahalogeno-diphenylglycolurils
Moretti, Florian,Poisson, Guillaume,Marsura, Alain
, p. 173 - 183 (2016/05/19)
1,3,4,6-Tetrachloro (TCDGU) and 1,3,4,6-tetrabromo-3α,6α-diphenylglycolurils smooth halogen oxidizers have been exploited in a new direction as reagents for free radical substitution toward some N-halosuccinimide nonreactive bis-heterocycles. An unexpected selectivity and reactivity were observed with methyl benzenes, methyl heterocycles, and methyl-bis-heterocycles of interest. A chemometric study has been performed to optimize five independent factors of the chlorination reaction with TCDGU. The predictive model was established either for the halogenation conversion and the ratio of monochlorination.
Synthesis and thermal decomposition of N,N-dialkoxyamides
Digianantonio, Katherine M.,Glover, Stephen A.,Johns, Jennifer P.,Rosser, Adam A.
body text, p. 4116 - 4126 (2011/06/28)
N,N-Dialkoxyamides 1c, a virtually unstudied member of the new class of anomeric amides, amides bearing two electronegative atoms at nitrogen, have been synthesised in useful yields directly from hydroxamic esters using phenyliodine(iii)bis(trifluoroacetate) (PIFA). Infrared carbonyl stretch frequencies and carbonyl 13C NMR properties have been reported, which support strong inhibition of amide resonance in these amides. Their thermal decomposition reactions in mesitylene at 155°C proceed by homolysis to form alkoxyamidyl and alkoxyl free radicals in preference to HERON rearrangements to esters. The reactions follow first-order kinetics and for a series of N,N-dimethoxy-4-substituted benzamides, activation energies of 125-135 kJ mol-1 have been determined together with weakly negative entropies of activation.
Bis- N -heterocyclic carbene palladium(IV) tetrachloride complexes: Synthesis, reactivity, and mechanisms of direct chlorinations and oxidations of organic substrates
McCall, A. Scott,Wang, Hongwang,Desper, John M.,Kraft, Stefan
scheme or table, p. 1832 - 1848 (2011/04/15)
This Article describes the preparation and isolation of novel octahedral CH2-bridged bis-(N-heterocyclic carbene)palladium(IV) tetrachlorides of the general formula LPdIVCl4 [L = (NHC)CH 2(NHC)] from LPdIICl2 and Cl2. In intermolecular, nonchelation-controlled transformations LPdIVCl 4 reacted with alkenes and alkynes to 1,2-dichlorination adducts. Aromatic, benzylic, and aliphatic C-H bonds were converted into C-Cl bonds. Detailed mechanistic investigations in the dichlorinations of alkenes were conducted on the 18VE PdIV complex. Positive solvent effects as well as kinetic measurements probing the impact of cyclohexene and chloride concentrations on the rate of alkene chlorination support a PdIV-Cl ionization in the first step. Product stereochemistry and product distributions from various alkenes also support Cl+-transfer from the pentacoordinated PdIV-intermediate LPdIVCl 3+ to olefins. 1-Hexene/3-hexene competition experiments rule out both the formation of π-complexes along the reaction coordinate as well as in situ generated Cl2 from a reductive elimination process. Instead, a ligand-mediated direct Cl+-transfer from LPd IVCl3+ to the π-system is likely to occur. Similarly, C-H bond chlorinations proceed via an electrophilic process with in situ formed LPdIVCl3+. The presence of a large excess of added Cl- slows cyclohexene chlorination while the presence of stoichiometric amounts of chloride accelerates both PdIV-Cl ionization and Cl+-transfer from LPdIVCl3 +. 1H NMR titrations, T1 relaxation time measurements, binding isotherms, and Job plot analysis point to the formation of a trifurcated Cl-...H-C bond in the NHC-ligand periphery as a supramolecular cause for the accelerated chemical events involving the metal center.
THERAPEUTIC SUBSTITUTED CYCLOPENTANES FOR REDUCING INTRAOCULAR PRESSURE
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Page/Page column 29, (2009/03/07)
Disclosed herein are compounds having formula (I) wherein a dashed line represents the presence or absence of a bond; Y is an organic acid functional group, or an amide or ester thereof; or Y is hydroxymethyl or an ether thereof; or Y is a tetrazolyl func
Interpretation of retention indices in gas chromatography for establishing structures of isomeric products of alkylarenes radical chlorination
Zenkevich
, p. 270 - 280 (2007/10/03)
By an example of previously uncharacterized products obtained by alkylarenes radical chlorination was demonstrated that combination of various interpretation methods applied to the retention indices (RI) in the gas chromatography on the standard nonpolar phases (comparison of RI of products and initial compounds, characteristics of succession of the chromatographic elution of the structural isomers with the use of estimation of molecular dynamic parameters, application of the additive schemes to RI calculation, and using of structural analogy CH3?Cl for testing the results obtained) permitted unambiguous identification of the structure even without data of mass spectrometry.
Carbazolyl nitrenium cations: Generation and reactions
Bogdal, Dariusz
, p. 2679 - 2688 (2007/10/03)
Carbazolyl nitrenium cations were generated during the thermolysis and photolysis of 1-carbazol-9-yl-2,4,6-triphenylpyridinium (Py+-Cz) tetrafluoroborate in 2,2,2-trifluoroethanol- and TFA - mesitylene mixtures. The thermolysis of Py+-Cz in TFA-mesitylene mixture gave 9-mesitylcarbazole in good yield along with carbazole, non-symmetrical mesitylene dimer, 2,4,6-triphenylpyridine, and a small amount of 9-(3,5-dimethylbenzyl)carbazole, whereas the thermolysis in trifluoroethanol - mesitylene mixture gave 9-mesitylcarbazole as the main product along with carbazole and 2,4,6-triphenylpyridine. The product distributions lead to two major conclusions. First, photolysis and thermolysis of Py+-Cz salt produce nitrenium ions that can be in singlet or triplet state dependant on the reaction conditions. Second, the carbazolyl nitrenium ion exhibits singlet state in the ground state.
