- The standard molar enthalpies of formation of some alkyladamantanes
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The standard massic energies of combustion of three alkyl-derivative of adamantane were measured at T = 298.15 K by static-bomb combustion calorimetry. The standard molar enthal pi es of formation in the liquid and gaseous states were obtained from these data. The enthalpies of some reactions of isomerization were calculated from the equilibrium study and compared with the results of calorimetric measurements.
- Melkhanova,Pimenova,Kolesov,Pimerzin,Sarkisova
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Read Online
- Study of the liquid-vapor critical temperatures for methyladamantanes and their mixtures with cyclohexane
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The liquid-vapor critical temperatures of individual 1,3-dimethyl-and 1,3,5-trimethyladamantanes and their binary mixtures with cyclohexane were determined over the entire range of composition by means of the ampule method. It was found that an excess of the critical temperatures over calculated values reached 20 K for both mixtures studied. The predictive capabilities of several calculation methods are discussed. Nauka/Interperiodica 2006.
- Nazmutdinov,Sarkisova,Vodenkova,Nesterov,Nesterova
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Read Online
- Synthesis of 1,3-dimethyladamantane by skeletal rearrangement of C 12H18 and C12H20 hydrocarbons over Na/H-Y-zeolite
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Granular binder-free Y-zeolite with a degree of Na+/H + ion exchange of 0.97 efficiently catalyzed isomerization of tetracyclo[6.2.1.13,6.02,7]dodecane and (2aR,5aα,8aR,8bα)-dodecahydroacenaphthene (perhydroacenaphthene) to 1,3-dimethyladamantane.
- Khusnutdinov,Kislitsina,Khazipova,Kutepov
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Read Online
- Exhaustive One-Step Bridgehead Methylation of Adamantane Derivatives with Tetramethylsilane
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A methylation protocol of adamantane derivatives was investigated and optimized using AlCl3 and tetramethylsilane as the methylation agent. Substrates underwent exhaustive methylation of all available bridgehead positions with yields ranging from 62 to 86 %, and up to six methyl groups introduced in one step. Scaling-up of the reaction was demonstrated by performing the >40 gram-scale synthesis of 1,3,5,7-tetramethyladamantane with 62 % yield. For several substrates, rearrangements were observed, as well as cleavage of functional groups or Csp3?Csp2 bonds or even cyclohexyl-adamantyl bonds. Based on mechanistic studies, it is suggested that a reactive methylation complex is formed from tetramethylsilane and AlCl3. X-ray diffraction structures of hexamethylated bis-adamantyls reveal elongation or widening of sp3 carbon bonds between adamantyl moieties to 1.585(3) ? and 125.26(9)° due to repulsive H???H contacts.
- Bonsir, Maxime,Davila, Christian,Geerts, Yves,Kennedy, Alan R.
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supporting information
p. 5227 - 5237
(2021/10/19)
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- Temperature Controls Guest Uptake and Release from Zn4L4 Tetrahedra
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We report the preparation of triazatruxene-faced tetrahedral cage 1, which exhibits two diastereomeric configurations (T1 and T2) that differ in the handedness of the ligand faces relative to that of the octahedrally coordinated metal centers. At lower temperatures, T1 is favored, whereas T2 predominates at higher temperatures. Host-guest studies show that T1 binds small aliphatic guests, whereas T2 binds larger aromatic molecules, with these changes in binding preference resulting from differences in cavity size and degree of enclosure. Thus, by a change in temperature the cage system can be triggered to eject one bound guest and take up another.
- Zhang, Dawei,Ronson, Tanya K.,Güryel, Songül,Thoburn, John D.,Wales, David J.,Nitschke, Jonathan R.
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supporting information
p. 14534 - 14538
(2019/10/11)
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- Dehydroxymethylation of alcohols enabled by cerium photocatalysis
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Dehydroxymethylation, the direct conversion of alcohol feedstocks as alkyl synthons containing one less carbon atom, is an unconventional and underexplored strategy to exploit the ubiquity and robustness of alcohol materials. Under mild and redox-neutral reaction conditions, utilizing inexpensive cerium catalyst, the photocatalytic dehydroxymethylation platform has been furnished. Enabled by ligand-to-metal charge transfer catalysis, an alcohol functionality has been reliably transferred into nucleophilic radicals with the loss of one molecule of formaldehyde. Intriguingly, we found that the dehydroxymethylation process can be significantly promoted by the cerium catalyst, and the stabilization effect of the fragmented radicals also plays a significant role. This operationally simple protocol has enabled the direct utilization of primary alcohols as unconventional alkyl nucleophiles for radical-mediated 1,4-conjugate additions with Michael acceptors. A broad range of alcohols, from simple ethanol to complex nucleosides and steroids, have been successfully applied to this fragment coupling transformation. Furthermore, the modularity of this catalytic system has been demonstrated in diversified radical-mediated transformations including hydrogenation, amination, alkenylation, and oxidation.
- Zhang, Kaining,Chang, Liang,An, Qing,Wang, Xin,Zuo, Zhiwei
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supporting information
p. 10556 - 10564
(2019/08/20)
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- Dehydroxymethylation of Alcohols Enabled by Cerium Photocatalysis
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Dehydroxymethylation, the direct conversion of alcohol feedstocks as alkyl synthons containing one less carbon atom, is an unconventional and underexplored strategy to exploit the ubiquity and robustness of alcohol materials. Under mild and redox-neutral reaction conditions, utilizing inexpensive cerium catalyst, the photocatalytic dehydroxymethylation platform has been furnished. Enabled by ligand-to-metal charge transfer catalysis, an alcohol functionality has been reliably transferred into nucleophilic radicals with the loss of one molecule of formaldehyde. Intriguingly, we found that the dehydroxymethylation process can be significantly promoted by the cerium catalyst, and the stabilization effect of the fragmented radicals also plays a significant role. This operationally simple protocol has enabled the direct utilization of primary alcohols as unconventional alkyl nucleophiles for radical-mediated 1,4-conjugate additions with Michael acceptors. A broad range of alcohols, from simple ethanol to complex nucleosides and steroids, have been successfully applied to this fragment coupling transformation. Furthermore, the modularity of this catalytic system has been demonstrated in diversified radical-mediated transformations including hydrogenation, amination, alkenylation, and oxidation.
- Zhang, Kaining,Chang, Liang,An, Qing,Wang, Xin,Zuo, Zhiwei
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supporting information
p. 10556 - 10564
(2019/08/28)
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- A 1,3-dimethyladamantane method for the preparation of
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The invention relates to the field of chemistry, and in particular to a preparation method of 1,3-dimethyladamantane. The preparation method comprises the following steps of: A, by taking perhydroacenaphthene as a raw material, adding aluminum chloride anhydrous as a catalyst, continuously dropping a small amount of water at 80-100 DEG C, and carrying out rearrangement reaction to obtain 1,3-dimethyladamantane reaction liquid; B, removing the aluminum trichloride catalyst to obtain crude 1,3-dimethyladamantane; C, rectifying the crude 1,3-dimethyladamantane obtained in the step B through a rectifying tower to obtain 1,3-dimethyladamantane. The preparation method of 1,3-dimethyladamantane has the advantages of being simple in operation, clean, environment-friendly, high in yield and low in equipment investment.
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Paragraph 0008-0010
(2017/03/08)
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- METHOD FOR PRODUCING 1,3-DIMETHYLADAMANTANE
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According to the present invention, a method can be provided for producing 1,3-dimethyladamantane represented by formula (2) by performing a skeletal isomerization reaction using, as catalysts, 0.5 to 1 .5 parts by weight of HF and 0.05 to 0.5 parts by weight of BF3 with respect to 1 part by weight of perhydroacenaphthene represented by formula (1) under a reaction temperature of 60 to 110° C.
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Paragraph 0041
(2013/09/12)
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- Direct observation of cyclic carbenium ions and their role in the catalytic cycle of the methanol-to-olefin reaction over chabazite zeolites
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Carbenium ions in zeolites: Two important carbenium ions have been observed for the first time under working conditions of the methanol-to-olefins (MTO) reaction over chabazite zeolites using 13C NMR spectroscopy. Their crucial roles in the MTO
- Xu, Shutao,Zheng, Anmin,Wei, Yingxu,Chen, Jingrun,Li, Jinzhe,Chu, Yueying,Zhang, Mozhi,Wang, Quanyi,Zhou, You,Wang, Jinbang,Deng, Feng,Liu, Zhongmin
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supporting information
p. 11564 - 11568
(2013/11/06)
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- Evaluation of cyclopentyl methyl ether (CPME) as a solvent for radical reactions
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We have explored the potential of cyclopentyl methyl ether (CPME) as a solvent for radical reactions. Hydrostannation, hydrosilylation, hydrothiolation, and tributyltin hydride mediated reductions were successfully carried out in CPME. GC-MS analysis indicated that CPME degraded into methyl pentanoate, cyclopentanone, 2-cyclopenten-1-ol, and cyclopentanol under thermal radical conditions, albeit only slightly. We also achieved radical-containing one-pot reactions in CPME as a demonstration of its applicability to multi-step reactions.
- Kobayashi, Shoji,Kuroda, Hiroyuki,Ohtsuka, Yuta,Kashihara, Takashi,Masuyama, Araki,Watanabe, Kiyoshi
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p. 2251 - 2259
(2013/03/29)
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- A PROCESS FOR PREPARING MEMANTINE
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The present invention relates to a process for preparing memantine, or a pharmaceutically acceptable salt thereof (e.g., memantine hydrochloride), which is substantially free of impurities.
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Page/Page column 20
(2010/08/08)
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- Black-light-induced radical/ionic hydroxymethylation of alkyl iodides with atmospheric co in the presence of tetrabutylammonium borohydride
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(Figure Presented) Tin-free radical/ionic hydroxymethylation of secondary and tertiary alkyl iodides proceeded efficiently in the presence of tetrabutylammonium borohydride as the hydrogen source under atmospheric pressure of CO In conjunction with photoirradiation using black light. Two possible mechanisms were proposed, both of which involve hybrid radical/ionic processes.
- Kobayashi, Shoji,Kawamoto, Takuji,Uehara, Shohei,Fukuyama, Takahide,Ryu, Ilhyong
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scheme or table
p. 1548 - 1551
(2010/07/06)
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- Carbenes in polycyclic systems: Generation and fate of potential adamantane-1,3-dicarbenes
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Potential formation and reactions of adamantane-1,3-dicarbenes 1-3 generated under different conditions and from different precursors, such as sodium salt of adamantane-1,3-dicarbaldehyde ditosylhydrazone (4a), sodium salt of 1,3-diacetyladamantane ditosylhydrazone (5a), sodium salt of 1,3-dibenzoyladamantane ditosylhydrazone (6a), and 1,3-bis(diazobenzyl) adamantane (7) are reported. Carbene species generated thermally from 4a yielded bishomoa-damantane (15), as a final product, via intramolecular insertion into adjacent C - C bond and formation of putative anti-Bredt olefin species, followed by hydrogen abstraction. Pyrolysis of the same sodium salt 4a in the presence of hydrogen donor n-Bu3SnH afforded 1,3-dimethyladamantane (17). Thermal decomposition of sodium salt 5a afforded 1,3-divinyladamantane (14). However, thermal decomposition of sodium salt 6a and diazo-precursor 7 gave benzonitrile as a sole identified product. On the contrary, photolysis of 7 afforded dimeric azine 21. Finally, the synthetic pathways of novel tosylhydrazone derivatives 4, 5, 6 and their corresponding sodium salts, as well as bis-diazocompound 7 are described. Copyright
- Klaic, Lada,Aleskovic, Marija,Veljkovic, Jelena,Mlinaric-Majerski, Kata
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p. 299 - 305
(2008/09/20)
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- Spurring radical reactions of organic halides with tin hydride and TTMSS using microreactors
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Tributyltin hydride-mediated radical reactions of organic halides were successfully carried out in a continuous flow system using a microreactor. The reactions proceeded within a very short period of time, coupled with quickly decomposing radical initiators such as V-65 and V-70. The continuous flow reaction system was applied to gram scale synthesis of a key intermediate for furofuran lignans.
- Fukuyama, Takahide,Kobayashi, Masahide,Rahman, Md Taifur,Kamata, Naoya,Ryu, Llhyong
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p. 533 - 536
(2008/04/05)
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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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- Compounds for photoresist and resin composition for photoresist
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The photoresist resin composition comprises a polymer having an adamantane skeleton represented by the following formula and a photoactive acid precursor: wherein R1represents a hydrogen atom or a methyl group; R2, R3, and R4are the same or different from each other, each representing a hydrogen atom, a halogen atom, an alkyl group, a hydroxyl group, a hydroxylmethyl group, a carboxyl group, a functional group which forms a hydroxyl group, a hydroxymethyl group or a carboxyl group by elimination with an acid; at least one of the substituents R2to R4is the functional group defined above; X represents an ester bond or an amide bond; and each of m and n is 0 or 1. The above photoresist resin composition is highly resistant to an etching solution, solubilizable by irradiation with light, and capable of giving minute patterns.
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- Thermodynamics of vaporization of some alkyladamantanes
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The boiling temperature of 1,3-dimethyladamantane was measured by comparative ebulliometry over the pressure range 6 b = 476.53 K, were derived. The enthalpy of vaporization, Δ1gHmo = (49.21 ± 0.2) kJ·mol-1, was calorimetrically measured at T = 308.15 K. The experimental and calculated Δ1gHmo values were found to agree within the error limits. Densities of the liquid phase were measured at the temperatures (293.15, 298.15, and 303.15) K. The experimental vapour pressures of 1,3-dimethyladamantane and of the previously studied 1,3,5-trimethyladamantane were extrapolated to the regions of the liquid phases from the triple to the critical temperatures.
- Varushchenko,Pashchenko,Druzhinina,Abramenkov,Pimersin
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p. 733 - 744
(2007/10/03)
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- Hemicarcerands that encapsulate hydrocarbons with molecular weights greater than two hundred
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Syntheses are reported for the globe-shaped hemicarcerands 1 and 2 composed of two rigid bowl-like units (polar caps) attached to one another at their rims through four OCH2C≡CC≡CCH2O units (equatorial spacers). Eight pendant CH3(CH2)4 groups in 1 and C6H5CH2CH2 groups in 2 attached in assemblies of four to each polar cap render the hosts soluble in organic solvents. The important shell-closing reactions 2Ar(OCH2C≡CH)4 + [O] → Ar(OCH2C≡CC≡CCH2O)4Ar went in 5-8% yields in pyridine-O2-Cu(OAc)2 to give a hemicarcerand free of pyridine. The higher solubility of 1 (compared to that of 2) in organic solvents led to an examination of its binding properties. By heating 1 dissolved either in potential guests or in 1,3,5-[(CH3)3C]3C6H3 (too large to enter 1) containing dissolved potential guests at 80-140 °C for 2-7 days, 1:1 hemicarceplexes mixed with the empty host were isolated in those cases when the potential guests were just small enough to enter the host's portals at high temperatures but large enough not to depart during isolation as stable solids. Thus, constrictive bonding played a large role in kinetic stabilization of the hemicarceplexes. The 1H NMR spectra of both the host and the guest were markedly modified upon complexation. The half-lives in hours of representative complexes dissolved in CDCl3 at 25 °C were as follows: 1·1,3,5-[(CH3)2CH]3C6H 3, 1628; 1·1,3,5-Et3C6H3, 960; 1·4-Et[2.2]paracyclophane, 24; 1·1,3-dimethyladamantane, 13.5; 1-[3.3]paracyclophane, 13; 1·tetradehydro[2.2]paracyclophane, 11; 1·[2.2]paracyclophane, 5; 1·4,12-dihydroxy[2.2]paracyclophane, 4; and 1·[2.3]paracyclphane, 0.5. Complexes of smaller guests such as CHCl3, ferrocene, adamantane, and 1,3,5-trimethylbenzene were unstable to room-temperature isolation conditions. Larger guests such as [3.4]paracyclophane and 4,12-dinitro[2.2]paracyclophane did not enter the portals of 1 at temperatures under which host 1 was stable, whereas smaller guests such as CH2Cl2 and pyridine entered and departed the host at 25 °C rapidly on the NMR time scale. Catalytic reduction (H2, PdC) of the eight acetylenic bonds of 1 produced an empty host of much more flexible structure, 3, whose binding properties have not yet been examined.
- Cram, Donald J.,Jaeger, Ralf,Deshayes, Kurt
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p. 10111 - 10116
(2007/10/02)
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- Tris(trimethylsilyl)silane as a Radical-Based Reducing Agent in Synthesis
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Tris(trimethylsilyl)silane is an effective reducing agent for organic halides, selenides, xanthates, and isocyanides, as well as an effective hydrosilylating agent for dialkyl ketones and alkenes.The silane functions as a mediator in the formation of intermolecular carbon-carbon bonds via radicals and allows a variety of organic substrates to be used as alkyl radical precursors.Absolute rate constants for the reaction of (Me3Si)3Si* radicals with a variety of organic compounds have been measured in solution by laser flash photolysis.At 294 K rate constants are >5 x 107 M-1 s-1 for C=C double bonds that are activated by neighboring ?-electron systems or by electron-withdrawing groups.For other substrates, reactivities decreased in the order xanthate > selenide > isocyanide > nitro > sulfide.
- Ballestri, M.,Chatgilialoglu, C.,Clark, K. B.,Griller, D.,Giese, B.,Kopping, B.
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p. 678 - 683
(2007/10/02)
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- ESR Study of 2-Substituted 2-Adamantyl Radicals. Configuration and Long-Range Hyperfine Interaction.
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Structure and long-range hyperfine interaction in 2-adamantyl, 5,7-dimethyl-2-adamantyl, and the various 2-substituted radicals (substituent = CH3, CH2SiMe3, OSiMe3, SSiMe3, CH2GeMe3, etc.) were studied by ESR.The origin of the long-range hyperfine interaction is discussed on the basis of the comparison between experimental and theoretical hfs values.The pyramidality of the radical center by a proper substituent at the 2-position of 2-adamantyl radicals has been found to exert significant influence to the long-range interaction.The analyses of hfs values for persistent 2-bis( trimethylsilyl)methyl-2-adamantyl radical and the 5,7-dimethyl derivative were made by the assistance of the ENDOR spectrum.The very small hfs values observed for the bis(trimethylsilyl)methyl methine protons not only show almost perpendicular arrangement of the Cα-Hβ bond to the singly occupied p? orbital but also suggest that the constant A in the Heller-McConnell equation would be positive on the basis of the positive temperature dependence.
- Kira, Mitsuo,Akiyama, Mieko,Ichinose, Michiko,Sakurai, Hideki
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p. 8256 - 8262
(2007/10/02)
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- THE OCTANT RULE. XX. SYNTHESIS AND CIRCULAR DICHROISM OF (1S,5S)-DIMETHYLADAMANTAN-2-ONE -- PREDICTED TO HAVE ZERO COTTON EFFECT
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The title compound was synthesized in optically active form from adamantane.Although the methyl perturbers lie in the extended local symmetry planes of the carbonyl chromophore, and octant and quadrant rules therefore predict they should make no contributions to the Cotton effect (CE), weak negative CEs are found in cyclopentane (Δεmax293 = -0.03) and in CF3CH2OH (Δεmax288 = -0.02) solvents.
- Lightner, David A.,Toan, Vien Van
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p. 4905 - 4916
(2007/10/02)
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- Contribution a l'etude des reactions d'alkylation et de polyalkylation de l'adamantane et de ses homologues
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A method for preparing alkyl derivatives of cage-structure compounds is proposed.It relies on the use of Grignard reactions with a high boiling point solvent.The reactions take place at atmospheric pressure.Methylation of adamantane, diamantane, and homoadamantane occurs with quantitative yield.With other primary alkyl groups, yields are better than 60percent.Competition between alkylation and secondary reactions is discussed on the basis of a free radical mechanism.
- Molle, G.,Dubois, J. E.,Bauer, P.
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p. 2428 - 2433
(2007/10/02)
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- ADAMANTANE AND ITS DERIVATIVES IN IONIC METHYLATION
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The ionic methylation of adamantane and 1-hydroxy-, 1-chloro-, and 1-bromoadamantanes was realized with tetramethylsilane in the presence of aluminum halides; the products were mono- and polyalkyladamantanes.Compounds of the adamantane series are methylated more readily than the analogous derivatives of cyclic and acyclic hydrocarbons of other types; the reaction takes place under mild conditions and leads to the production of methylation products with overall yields close to quantitative.
- Bolestova, G. I.,Parnes, Z. N.,Kursanov, D. N.
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p. 297 - 300
(2007/10/02)
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- Carbon-13 NMR Spectra of Some Methyl-Substituted Adamantanones
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The synthesis of 1-methyl- (2), 1,5-dimethyl- (3), and 5,7-dimethyladamantanone (4) and their 13C NMR spectra have been investigated.For the preparation of 3 and 4, some discrepancies existing in the literature are revealed.The carbon-13 NMR resonances of 2, 3, and 4, have been completely assigned from conventional high-resolution spectra with the use of a 1H-13C polarization transfer technique and lanthanide shift reagent experiments.Comparison of the chemical shift values with those of the parent adamantanone (1) and the tetramethyl derivative 5 indicates that the effects of methyl groups on the chemical shifts of adamantanone are similar in direction and magnitude to the effects observed in adamantane.The carbonyl group induces upfield shifts of the signals for carbons across the polycyclic system and for the methyl groups, especially at the adjacent bridgeheads.
- Farcasiu, Dan,Marino, Gaye,Rose, Kenneth D.
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p. 2762 - 2765
(2007/10/02)
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- TETRAMETHYLSILANE AS ALKYLATING AGENT IN REACTIONS WITH ALKYL HALIDES IN THE PRESENCE OF ALUMINIUM CHLORIDE AND ALUMINIUM BROMIDE
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A systematic investigation was undertaken into the electrophilic substitution of halogen atoms by a methyl group in alkyl halides by the action of tetramethylsilane and aluminium halides.It was established that the structure of the substrate has an effect on the reaction path.The methylation of primary alkyl halides is accompanied by isomerization of the carbon skeleton and leads to the production of saturated branched hydrocarbons.In the case of alkyl halides with a branched hydrocarbon chain difficultly obtainable hydrocarbons with a quarternary carbon atom are formed with high yields.The reaction takes place at room temperature in l0-l5 min.
- Bolestova, G. I.,Parnes, Z. N.,Latypova, F. M.,Kursanov, D. N.
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p. 1203 - 1208
(2007/10/02)
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- Process for producing alkyl adamantanes
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This invention relates to a process for producing alkyl adamantanes by reacting tetracyclododecanes and hydrogen in the presence of a specific catalyst.
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