- Rare Examples of Fe(IV) Alkyl-Imide Migratory Insertions: Impact of Fe - C Covalency in (Me2IPr)Fe(=NAd)R2 (R = neoPe, 1-nor)
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The iron(IV) imide complexes, (Me2IPr)-R2Fe=NAd (R = neoPe (3a), 1-nor (3b)) undergo migratory insertion to iron(II) amides (Me2IPr)RFe{NR(Ad)} (R = neoPe (4a), 1-nor (4b)) without evidence of imidyl
- Jacobs, Brian P.,Wolczanski, Peter T.,Jiang, Quan,Cundari, Thomas R.,MacMillan, Samantha N.
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- The mechanism of conversion of saturated hydrocarbons catalyzed by sulfated metal oxides: Reaction of adamantane on sulfated zirconia
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The high activity of sulfated zirconia (SZ) toward hydrocarbon conversions has been confirmed by the study of the isomerization of methylcyclopentane to cyclohexane. This catalytic activity is generally rationalized by the catalyst having superacidic strength. The reaction of methylcyclopentane with superacids is initiated, however, by the cleavage of a carbon-carbon bond with the formation of an acyclic carbocation, followed by hydride transfer giving the methylcyclopentyl cation which undergoes rearrangement. By contrast, no isohexanes (products of ring cleavage) were formed in the reaction on SZ, suggesting a different reaction mechanism. The mechanism of interaction of SZ with saturated hydrocarbons was elucidated by a study of adamantane. Small amounts of 1-adamantanol and adamantanone and traces of 2-adamantanol were observed after reaction at temperatures from 65 to 135°C, indicating that the reaction is an oxidation followed by hydride transfers. Small amounts of diadamantanes were also formed, proving that oxidation to carbocations goes through the free radical stage. At 150°C, additional reaction products were observed, 1-adamantanethiol (larger amount) and 2-adamantanethiol (smaller amount), indicating reduction of sulfate all the way to sulfide, which then traps the adamantyl cation in competition with the oxygen anions or water formed in the redox process. Ring cleavage and disproportionation to form alkyladamantanes and aromatics also occurred. Thus, the increase in activity of SZ over the parent oxide for carbocationic alkane and cycloalkane reactions can be ascribed to initiation through a one-electron oxidation of the hydrocarbon by sulfate to a carbocation precursor.
- Farcasiu, Dan,Ghenciu, Anca,Li, Jing Qi
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- Mechanochemical Grignard Reactions with Gaseous CO2 and Sodium Methyl Carbonate**
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A one-pot, three-step protocol for the preparation of Grignard reagents from organobromides in a ball mill and their subsequent reactions with gaseous carbon dioxide (CO2) or sodium methyl carbonate providing aryl and alkyl carboxylic acids in up to 82 % yield is reported. Noteworthy are the short reaction times and the significantly reduced solvent amounts [2.0 equiv. for liquid assisted grinding (LAG) conditions]. Unexpectedly, aryl bromides with methoxy substituents lead to symmetric ketones as major products.
- Pfennig, Victoria S.,Villella, Romina C.,Nikodemus, Julia,Bolm, Carsten
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supporting information
(2022/01/22)
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- Chemical Transformations of Tetracyclo[3.3.1.13,7.01,3]decane (1,3-Dehydroadamantane): IX. Noncatalytic Reactions with Alkylarenes
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Abstract: The reaction of 1,3-dehydroadamantane with alkylbenzenes was studied for the first time. It involved the C–H bond of the alkyl substituent in the α-position with respect to the aromatic ring. The proposed radical mechanism of the reaction was co
- Butov, G. M.,Mokhov, V. M.,Zubovich, E. A.
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p. 1041 - 1045
(2020/07/25)
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- Synthesis of rigid cores based on 1,1′-biadamantane
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An efficient strategy has been developed for the preparation of a series of rigid cores based on 1,1′-biadamantane. Disproportionation of bromobenzene in the alkylation was observed through the effect of AlCl3 or AlBr3. Proposed mechanisms of these reactions have also been outlined on the basis of the results obtained.
- Lai, Xiangfeng,Guo, Jianwei,Fu, Shuqin,Zhu, Dongyu
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p. 8677 - 8680
(2016/02/05)
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- Film forming composition, insulating film formed by use of the composition, and electronic device
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A film forming composition includes a polymer of a compound represented by formula (I): wherein R1, R2 and R3 each independently represents a substituent containing a carbon-carbon double bond or carbon-carbon triple bond; X1, X2 and X3 each independently represents any substituent; l and n each stands for an integer of from 0 to 15 and m stands for an integer of from 0 to 14, with the proviso that l, m and n do not represent 0 simultaneously; o and q each independently stands for an integer of from 0 to 15 and p independently stands for an integer of from 0 to 14; and r stands for 0 or 1, with the proviso that when r=0, R1 and R3 each independently represents a substituent containing a carbon-carbon double bond.
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- Electrocatalytic reduction of alkyl iodides in tetrahydrofuran at silver electrodes
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Recent interest in the electrocatalytic activity of silver towards the reduction of alkyl iodides has led us to investigate whether the effect is observed in tetrahydrofuran (THF) at room temperature. Using platinum electrodes in THF for the reduction of alkyl halides at 298 K has been hampered by the solvent window, which 'obscures' the voltammetric signals of interest. In order to overcome these problems, voltammetry has been performed at low temperature and was shown to extend the voltammetric window, leading to accurate electrochemical analyses and even novel changes in mechanism(s) of the reactive species following electron-transfer (ET). Herein, it is shown that for a primary and tertiary alkyl iodide in THF, electroreduction at silver leads to a significant shift in the reduction potential to more positive values compared to platinum. In addition, following reduction, a characteristic series of oxidation peaks are observed and are shown to be due to the specific activity of iodide ions towards silver following reductive cleavage of the parent alkyl iodide. This characteristic feature is not observed with other halide ions: bromide and chloride. Preparative electrolyses at controlled-potential have suggested that the reduction of the above alkyl iodides is a one-electron concerted process. The 'free' iodide ions act as a monitor of reaction progression, and the carbon-centred radical either dimerises and/or abstracts a hydrogen atom from the electrolyte/solvent; 1-iodoadamantane giving percentage yields of 58% adamantane and 39% 1,1'-biadamantane, the primary alkyl iodide, prepared in-house, giving 67% R-H and 25% R-R. Copyright
- Paddon, Christopher A.,Bhatti, Farrah L.,Donohoe, Timothy J.,Compton, Richard G.
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p. 115 - 121
(2007/10/03)
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- Alkylation of adamantane with alkyl halides catalyzed by ruthenium complexes
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The feasibility of catalytic alkylation of adamantane and 1-bromoadamantane with alkyl halides in the presence of ruthenium-containing catalysts was revealed. The optimum molar ratios between the catalyst components and the reactants, as well as the reaction conditions for the selective synthesis of mono-and dialkylsubstituted adamantane derivatives with a 70-98% yield, were determined. Nauka/Interperiodica 2006.
- Khusnutdinov,Schchadneva,Malikov,Dzhemilev
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p. 159 - 163
(2007/10/03)
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- Reduction of organic halides with lanthanum metal: A novel generation method of alkyl radicals
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Results of the reaction of alkyl halides with lanthanum metal have been shown. The reduction of alkyl iodide with 1/3 equiv of lanthanum metal efficiently proceeded to give the corresponding reductive dimerized products along with the formation of reduction and dehydroiodination products. In the case of alkyl bromides and chlorides, the reaction did not proceed under the same reaction conditions as that of alkyl iodides; however, the reaction was dramatically promoted by the addition of a catalytic amount of iodine. A reaction pathway including alkyl radicals was suggested.
- Nishino, Toshiki,Watanabe, Toshihisa,Okada, Mitsuo,Nishiyama, Yutaka,Sonoda, Noboru
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p. 966 - 969
(2007/10/03)
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- Photochemistry of aryl tert-butyl ethers in methanol: The effect of substituents on an excited state cleavage reaction
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The photolysis of a set of 10 substituted aryl tert-butyl ethers, 8a-j, in methanol gave, as the major product, the corresponding phenol along with tert-butyl-substituted phenols resulting from photo-Fries reaction. The corresponding 4-cyanophenyl 1-adamantyl ether, 9, also gave 1-meth-oxyadamantane 16 (16%), indicating that, at least for this ether, some of the products were ion-derived. Quenching studies with 2,3-dimethylbutadiene for the tert-butyl ethers indicated that these reactions were occurring from the singlet excited state. Rate constants for the reaction, obtained from quantum yields and singlet lifetimes, were found to correlate reasonably well with σhv values, ρ = -0.77 (r = 0.975), a result that is unexpected for a reaction where the polarity of the bond breaking in the transition state is expected to be -O(δ-)···C(δ+).
- DeCosta,Bennett,Pincock,Pincock,Stefanova
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p. 4162 - 4168
(2007/10/03)
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- Mechanochemical arylation and alkylation of fullerene C60 under the solvent-free conditions
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The mechanochemical reaction of fullerene C60 with organic bromides and alkali metals was found to give the corresponding aryl or alkyl C60 derivatives under the solvent-free conditions.
- Tanaka, Toru,Komatsu, Koichi
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p. 4397 - 4402
(2007/10/03)
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- Rodlike molecules by Kolbe electrolysis
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A new short and simple pathway to rigid, rod-shaped hydrocarbon skeletons, in particular of the oligo-bicyclo[2.2.2]octane type, is described. The key step consists of an electrochemical C-C bond coupling reaction between bridgehead positions of bi- and tricyclic carboxylic acids. Functional groups can be retained, they influence the yield of the C-C bond connection. In this way, otherwise difficult or laborious syntheses are shortened, and rigid, non-collapsable nano size spacer units are easily available. The optimized electrochemical procedures are described in detail.
- Nuding,V?gtle,Danielmeier,Steckhan
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- Thermolysis of Highly Congested Tri-tert-alkylmethanes. Rearrangement of a 3-Noradamantylmethyl Radical
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Activation energies for C-Ad fission in the thermolysis of di-1-adamantyl-tert-alkylmethanes and 1-adamantyl-di-1-bicyclooctylmethane, AdR1R2CH, in toluene are best correlated with the strain energy difference (MMP2 force field) between the methane and the corresponding radical, R1R2C radical H; difficulties were encountered in the application of MM3 to certain of these trialkylmethanes.Normally, the major thermolysis product is the di-tert-alkylmethane, R1R2CH2, but when a 3-noradamantly group is present (1d) the initially formed radical ring opens to give 1,2'-biadamantyl in amounts which depend on the temperature and the solvent (normal or octadeuteriated).This rearrangement is readily explained by MMP2 calculations.Since the cross-product yield is low (less than 3percent, even in deuteriated solvent at the highest temperature) the thermodynamic parameters for the hydrogen transfer and ring opening reactions of the 1-adamantyl-3-noradamantylmethyl radical can be compared directly.Both the activation enthalpy and entropy are much greater for ring opening than for hydrogen abstraction from the solvent.Isotope effects on hydrogen abstraction are high and satisfy certain criteria for tunnelling, as do data on the analogous reaction of Ad2C radical H.A more sophisticated treatment of the product composition for 1d thermolysis, using kinetic simulation, leads to essentially the same conclusions as the simpler treatment.
- Lomas, John S.
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p. 519 - 528
(2007/10/02)
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- Catalytic reaction of halogenoadamantanes
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1,1'-Biadamantyl, 1,3-dehydroadamantane, and 3-methylenebicyclonon-6-ene were obtained by the catalytic reaction of 1-halogeno-, 1,3-dihalogeno, and cis-1,4-dibromoadamantane respectively with lithium in the presence of methyldiphenylchlorosilane.The methyldiphenylchlorosilane acts as a supplier of active lithium in the form of methyldiphenylsilyllithium.
- Son, V.V.,Son, T.V.
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p. 2081 - 2083
(2007/10/02)
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- The Reactions of 1-Adamantyl Radicals with Acetonitrile and Their Bearing on Oxidative Decomposition of 1,1'-Azoadamantane
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1-Adamantyl radicals (Ad.) have been generated photochemically from azo-1,1'-adamantane (AA) in acetonitrile (MeCN).Product analysis by GC accounted for 98percent of the Ad groups as a mixture of adamantane (AdH), 1,1'-biadamantane (AdAd), and the coupling product (5) of Ad(Me)C=N. with solvent-derived .Ch2CN.The remaining 57percent of the .CH2CN groups thet could be found appeared as succinonitrile.Kinetic modeling of the product distribution shows that Ad. abstracts hydrogen from MeCN roughly four times as fast as it adds to the nitrile carbon .In our previous work on the oxidative decomposition of AA in MeCN, induced by the thianthrenecation radical (Th.+), very little AdH but significantly larger amounts of AdAd and AdCOMe were obtained.We propose, therefore, that virtually no free Ad. is formed or survives oxidation in the oxidative decomposition of AA.Further, the AdAd found in the oxidative reaction cannot have come from the dimerization of free Ad. but may have arisen, instead, from the biadamantane cation radical (AdAd.+), formed within a solvent cage.
- Engel, Paul S.,Lee, Wang-Keun,Marschke, Gregor E.,Shine, Henry J.
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p. 2813 - 2817
(2007/10/02)
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- REACTION OF ORGANOMAGNESIUM COMPOUNDS OF THE ADAMANTANE SERIES WITH CARBONYL COMPOUNDS
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In the transformations of organomagnesium compounds of the adamantane series involving aldehydes, ketones, esters, and acid chlorides the nature of the reaction products and their yields are determined by the steric hindrances at the reaction centers of the organomagnesium and carbonyl compounds and by the ease of homolysis of the C-H bonds of the carbonyl reagent.The retardation of the faster addition of the Grignard reagent at the carbonyl group as a result of steric hindrances permits homolytic removal of a hydrogen atom from the carbonyl compounds by the adamantyl radical.
- Yurchenko, A. G.,Fedorenko, T. V.
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p. 875 - 880
(2007/10/02)
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- ELECTRON-TRANSFER REACTIONS OF ORGANOSULFUR CATION RADICALS
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The thianthrene cation radical (Th.+) undergoes electron transfer in reactions with a number of azoalkanes.The oxidized azoalkanes then enter primarily into carbocation reaction pathways rather than the free radical pathways with which they are commonly associated.Examples are given with 1,1'-azoadamantane, phenylazotriphenylmethane, azotoluene, and azo-tertiary-butane.Reactions of Th.+ with Grignard agents also result, to varying extents, in electron transfer from the Grignard to Th.+.Here again carbocation chemistry is seen but particularly with solvent tetrahydrofuran, which polymerizes.The Grignard group may end up primarily as alkane (e.g., with t-butyl) or may also be trapped by Th.+ in the form of a 5-alkylthianthreniumyl ion (e.g. with butyl).Possible mechanisms of reactions are discussed.
- Shine, Henry J.,Bae, Dong Hak,Hoque, A. K. M. Mansurul,Kajstura, Alojzy,Lee, Wang Keun,et al.
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p. 111 - 142
(2007/10/02)
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- SYNTHESIS OF 1-ADAMANTYLMAGNESIUM BROMIDE
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The reaction of 1-bromoadamantane and magnesium was studied preparatively and kinetically.Under the normal conditions for the production of Grignard reagents 1-adamantylmagnesium bromide is formed with a yield of up 64percent.Molecular oxygen increases the rate of this reaction.The reaction rate is determined by the diffusion of the bromide to the surface of the magnesium, by the desorption of the organomagnesium compound to the surface of the magnesium, and by the presence and density of the "black layer".
- Yurchenko, A. G.,Fedorenko, T. V.,Rodionov, V. N.
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p. 1529 - 1532
(2007/10/02)
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- Photostimulated Reaction of 1-Haloadamantane and 9-Bromotriptycene with Nucleophiles. A Nucleophilic Substitution by SRN1 at the Bridgehead Position
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1-Haloadamantanes and 9-bromotriptycene react under irradiation with diphenylphosphide and diphenylarsenide ions to give the substitution product in good yields. 1-Iodoadamantane (8) also reacts with disodium telluride and disodium selenide under irradiation to give di-1-adamantyl ditelluride and di-1-adamantyl diselenide, respectively. 9,10-Dibromotriptycene with diphenylphosphide gives a good yield of the disubstitution product.It seems that all these reactions occur by the SRN1 mechanism.Substrate 8 reacts under irradiation with carbanionic nucleophiles and diethyl phosphite ion, but the products are adamantane and 1,1'-biadamantyl rather than substitution products.These nucleophiles transfer an electron to 8 to form radical anions which fragment to 1-adamantyl radicals.The radicals are reduced or dimerized.In contrast, amide ions do not react with 8.The ease of the halogen nucleofugality is I > Br > Cl, the same as in the aromatic system.
- Palacios, Sara M.,Santiago, Ana N.,Rossi, Roberto A.
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p. 4609 - 4613
(2007/10/02)
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- A Product Study of 1-Adamantyl and 1-Bicyclooctyl Radicals in Hydrocarbon Solvents. An Unusually Large Hydrogen Isotope Effect
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1-Adamantyl (ada.) and 1-bicyclooctyl (bo.) radicals have been generated by photolysis of the corresponding azoalkanes in various hydrocarbon solvents.Both radicals abstract hydrogen readily from hydrocarbons and they add to aromatic rings much faster than tert-butyl. does.Despite its reactivity, ada. is remarkably selective in hydrogen atom abstraction, preferring a benzylic hydrogen 25:1 over a cyclohexane hydrogen.The effect of solvent viscosity indicates that formation of the radical dimers biada and bibo occurs in the solvent cage.The most striking result of this work is a deuterium isotope effect of 25 for hydrogen transfer from cyclohexane to ada. at 65 deg C.Steric compression in the transition state is postulated to cause an unusually large tunnel correction and hence a large kH/kD.
- Engel, Paul S.,Chae, Woo-Ki,Baughman, Sharon A.,Marschke, Gregor E.,Lewis, Edward S.,et al.
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p. 5030 - 5034
(2007/10/02)
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- Reluctant Azoalkanes: The Photochemical Behavior of Acyclic, Bridgehead-Centered Azoalkanes on 185- and 350-nm Irradiation
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Azo-1-adamantane (1a), azobicyclooctanes (1b and 1c), and azo-1-norbornane (1d) isomerize to cis-azoalkanes but are reluctant to lose nitrogen directly upon long-wavelength irradiation.Use of 185-nm light is shown to enhance deazatization quantum yields considerably, though photoisomerization remains an important reaction.In the case of 1a especially, thermolysis of the cis isomer is the dominant decomposition mechanism at long and probably at short wavelength; however, the cis isomer of 1d is thermally stable.It follows that the second excited singlet state is responsible for deazatization of 1d.The products of photolyisis in pentane have been identified, and the amount of bridgehead radical hydrogen abstraction relative to recombination is found to increase under short-wavelength irradiation.
- Adam, Waldemar,Mazenod, Francois,Nishizawa, Yoshinori,Engel, Paul S.,Baughman, Sharon A.,et al.
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p. 6141 - 6145
(2007/10/02)
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- High-Yield Direct Synthesis of a New Class of Tertiary Organolithium Derivatives of Polycyclic Hydrocarbons
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For the first time, 1- and 2-adamantyllithium, 1-diamantyllithium, 3,5,7-trimethyl-1-adamantyllithium, 1-twistyllithium, 3-methyl-7-noradamantyllithium, 1-triptycyllithium, and 3-homoadamantyllithium have been directly synthesized from the reaction of an organic halide and lithium metal.By use of certain experimental parameters, the phenomena at the metal-solution interface are controlled, thereby resulting in exceptionally high yields of this new class of organometallic compounds (>75percent, except in the case of 3-homoadamantyllithium).Competition between formation of the organometallic compound and formation of solvent-attack byproducts is determined by the degree of adsorption of the transient species (anion radical RX-. or radical pair R..Li) generated at the metal surface during attack by the halogenated derivative.
- Molle, G.,Bauer, P.,Dubois, J. E.
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p. 2975 - 2981
(2007/10/02)
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- The Barbier Synthesis: A One-Step Grignard Reaction?
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Counter to generally accepted theory, it is demonstrated that the Byrbier synthesis does not necessarily involve the in situ formation of an organometallic compound.In certain cases, there is a radical pathway in which the anion radical (R.-X-) resulting from the attack by a halogenated derivative on lithium is directly trapped by the ketone or by the ketyl radical on the metal surface befor the organometallic compound forms.This pathway can be unique, as when 1-bromoadamantane condenses with adamantanone or hexamethylacetone.However, by extension of the Barbier synthesis to other "cage-structure" compounds homologous to adamantane, it is seen that the radical pathway can compete with the organometallic pathway and that this competition is principally determined by the stability of the cage radicals generated at the metal-solution interface.An optimum yield can be attained in this type of synthesis by choosing the Grignard reaction or the Barbier reaction, depending on the nature of the halogenated cage derivatives in use.
- Molle, Gerard,Bauer, Pierre
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p. 3481 - 3487
(2007/10/02)
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- Formation of Cage-Structure Organomagnesium Compounds. Influence of the Degree of Adsorption of the Transient Species at the Metal Surface
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Secondary and tertiary adamantyl organomagnesium compounds have been synthesized with yields of ca. 60percent by means of an original static procedure.By condensing Grignard reagents of adamantane over benzaldehyde, 70percent and 72percent yields of alcohol are obtained; the 1- and 2-adamantanecarboxylic acid chlorides give 40percent and 50percent yields of 1,1- and 2,2-diadamantyl ketone, respectively.Competition between the various reactions occuring either at the metal-solution interface (formation of the organomagnesium compound and of the dimerization hydrocarbon) or in the medium (formation of the solvent-attack products) is studied in terms of the stirring, the nature of the halogen, the basicity of the solvent, and the ratio of the magnesium surface to the halide.The kinetic study of the formation of these organomagnesium compounds demonstrates the essential role of the anion radical (RX) and of radical pair (RMgX), whose degrees of adsorption at the metal surface, i.e., electrostatic interaction between the transient species at the metal surface, after the single electron transfer (SET), determine the competition between the various reaction pathways.These degrees of adsorption are highly dependent on the nature of the cage structure of the radical.An XPS analysis at different depths of the deposit at the metal surface provides invaluable information on the phenomena occuring at the metal-solution interface when 1-bromoadamantane attacks the magnesium.This makes it possible to retrace the history of the reaction in its initial phase.
- Molle, G.,Bauer, P.,Dubois, J. E.
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p. 4120 - 4128
(2007/10/02)
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- Reaction of 1-Bromoadamantane with Diphenylphosphide and Diphenylarsenide Ions by the SRN1 Mechanism. Facile Nucleophilic Substitution at the Bridgehead Position
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The photostimulated reaction of 1-bromoadamantane (1) with diphenylphosphide (2) and diphenylarsenide (6) ions in liquid ammonia afforded good yields of the substitution products, together with small amounts of adamantane (4) and 1,1'-biadamantyl (5) as byproducts.The reaction of 1 with 2 in the dark did not occur, but stimulation with solvated electrons gives a small amount of the substitution product and 5, with a large amount of 4.The photostimulated reaction of 1 with 2 is inhibited by p-dinitrobenzene and di-tert-butyl nitroxide.All these results suggest that these reactions occur by the SRN1 mechanism of substitution, where radical and radical anions are intermediates.
- Rossi, Roberto A.,Palacios, Sara M.,Santiago, Ana N.
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p. 4654 - 4657
(2007/10/02)
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- VERY SLOW ROTATION ABOUT A CARBON-CARBON SINGLE BOND IN o-TOLYL-1,1'-DIADAMANTYLCARBINOL AND RELATED COMPOUNDS
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Previous work on the ap and sp rotamers of o-tolyldi-t-butylcarbinol (1a and 2a) has been extended to 1-adamantyl derivatives which are found to have abnormally high barriers to the ap->sp rotation.A semi-quantitative explanation of the activation enthalpies for this conformational change is proposed.Rotameric ap and sp o-tolyl-1-adamantyl-t-butylcarbinols (1b and 2b) and o-tolyl-1,1'-diadamantylcarbinols (1c and 2c) are synthesised by the addition of o-tolyl-lithium to 1-adamantyl-t-butylketone and 1,1'-diadamantylketone, respectively.In both cases the major product is the less stable ap isomer.The rotation rates of 1b and 1c in dodecane correspond to activation energies of 33.9 and 39.1 kcal/mol, respectively, even higher than that for 1a, 29.8 kcal/mol.Steric energies are calculated by molecular mechanics for model structures corresponding to the ap and sp isomers and to two points on the rotation pathway, giving extrapolated theoretical activation enthalpies in qualitative agreement with the experimental data.The enhanced steric effect of the 1-Ad group can be attributed to three factors : restricted rotation of the methylene groups as opposed to the methyl groups in t-Bu : increase in bond angle strain due to the terminal cyclohexane ring; increase in non-bonding interactions by buttressing effects of the terminal cyclohexane methine and methylene hydrogens.
- Lomas, John S.,Dubois, Jacques-Emile
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p. 2273 - 2278
(2007/10/02)
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