- 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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- Direct Deamination of Primary Amines via Isodiazene Intermediates
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We report here a reaction that selectively deaminates primary amines and anilines under mild conditions and with remarkable functional group tolerance including a range of pharmaceutical compounds, amino acids, amino sugars, and natural products. An anomeric amide reagent is uniquely capable of facilitating the reaction through the intermediacy of an unprecedented monosubstituted isodiazene intermediate. In addition to dramatically simplifying deamination compared to existing protocols, our approach enables strategic applications of iminium and amine-directed chemistries as traceless methods. Mechanistic and computational studies support the intermedicacy of a primary isodiazene which exhibits an unexpected divergence from previously studied secondary isodiazenes, leading to cage-escaping, free radical species that engage in a chain, hydrogen-atom transfer process involving aliphatic and diazenyl radical intermediates.
- Berger, Kathleen J.,Driscoll, Julia L.,Yuan, Mingbin,Dherange, Balu D.,Gutierrez, Osvaldo,Levin, Mark D.
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supporting information
p. 17366 - 17373
(2021/11/04)
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- Domino Methylenation/Hydrogenation of Aldehydes and Ketones by Combining Matsubara's Reagent and Wilkinson's Catalyst
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The methylenation/hydrogenation cascade reaction of aldehydes or ketones through a domino process involving two ensuing steps in a single pot is realized. The compatibility of Matsubara's reagent and Wilkinson's complex give a combination that allows, under dihydrogen, the transformation of a carbonyl function into a methyl group. This new method is suitable to introduce an ethyl motif from aromatic and aliphatic aldehydes with total chemoselectivity and total retention of α-stereochemical purity. The developed procedure is also extended to the introduction of methyl groups from ketones.
- Maazaoui, Radhouan,Pin-Nó, María,Gervais, Kevin,Abderrahim, Raoudha,Ferreira, Franck,Perez-Luna, Alejandro,Chemla, Fabrice,Jackowski, Olivier
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supporting information
p. 5732 - 5737
(2016/12/14)
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- Halogen Exchange Reaction of Aliphatic Fluorine Compounds with Organic Halides as Halogen Source
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The halogen exchange reaction of aliphatic fluorine compounds with organic halides as the halogen source was achieved. Treatment of alkyl fluorides (primary, secondary, or tertiary fluorides) with a catalytic amount of titanocene dihalides, trialkyl aluminum, and polyhalomethanes (chloro or bromo methanes) as the halogen source gave the corresponding alkyl halides in excellent yields under mild conditions. In the case of a fluorine/iodine exchange, no titanocene catalyst is needed. Only C-F bonds are selectively activated under these conditions, whereas alkyl chlorides, bromides, and iodides are tolerant to these reactions.
- Mizukami, Yuki,Song, Zhiyi,Takahashi, Tamotsu
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supporting information
p. 5942 - 5945
(2016/01/09)
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- Catalytic Ketone Hydrodeoxygenation Mediated by Highly Electrophilic Phosphonium Cations
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Ketones are efficiently deoxygenated in the presence of silane using highly electrophilic phosphonium cation (EPC) salts as catalysts, thus affording the corresponding alkane and siloxane. The influence of distinct substitution patterns on the catalytic effectiveness of several EPCs was evaluated. The deoxygenation mechanism was probed by DFT methods.
- Mehta, Meera,Holthausen, Michael H.,Mallov, Ian,Pérez, Manuel,Qu, Zheng-Wang,Grimme, Stefan,Stephan, Douglas W.
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p. 8250 - 8254
(2015/07/07)
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- 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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p. 1273 - 1278
(2013/11/06)
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- Cationic ring-opening polymerization of novel 1,3-dehydroadamantanes with various alkyl substituents: Synthesis of thermally stable poly(1,3-adamantane)s
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Cationic ring-opening polymerizations of 5-alkyl- or 5,7-dialkyl-1,3- dehydroadamantanes, such as 5-hexyl- (4), 5-octyl- (5), 5-butyl-7-isobutyl- (6), 5-ethyl-7-hexyl- (7), and 5-butyl-7-hexyl-1,3-dehydroadamantane (8), were carried out with super Bronsted acids, such as trifluoromethanesulfonic acid or trifluoromethanesulfonimide in CH2Cl2 or n-heptane. The ring-opening polymerizations of inverted carbon-carbon bonds in 4-8 proceeded to afford corresponding poly(1,3-adamantane)s in good to quantitative yields. Poly(4-8)s possessing alkyl substituents were soluble in 1,2-dichlorobenzene, although a nonsubstituted poly(1,3-adamantane) was not soluble in any organic solvent. In particular, poly(8) exhibited the highest molecular weight at around 7500 g mol-1 and showed excellent solubility in common organic solvents, such as THF, CHCl3, benzene, and hexane. The resulting poly(4-8)s containing adamantane-1,3-diyl linkages showed good thermal stability, and 10% weight loss temperatures (T10) were observed over 400 °C.
- Inomata, Sotaro,Harada, Yusuke,Nakamura, Yuya,Uehara, Yosuke,Ishizone, Takashi
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p. 4111 - 4124
(2013/09/23)
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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 0040
(2013/09/12)
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- Photoreduction of aliphatic and aromatic thioketals: New access to the reduction of carbonyl groups by a desulfurization chain process
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Aromatic and aliphatic ketones can be converted to methylene groups by desulfurization of the corresponding dithioketals in moderate to good yields. The reaction proceeds by photoinduced electron transfer from tert-BuOK in the presence of 1,4-dicyclohexadiene as hydrogen atom donor. The diene is able to trigger and keep a chain process by hydrogen transfer-proton transfer reactions.
- Oksdath-Mansilla, Gabriela,Argüello, Juan E.,Pe?é?ory, Alicia B.
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p. 1515 - 1518
(2013/03/14)
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- Electrochemical deoxygenation of primary alcohols
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Direct electrolysis of primary alcohols, in the presence of methyl toluate, leads smoothly to the formation of the corresponding deoxygenated product in high yield. Georg Thieme Verlag Stuttgart · New York.
- Lam, Kevin,Mark, István E.
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experimental part
p. 1235 - 1239
(2012/06/18)
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- The reaction of biphenyl radical anion and dianion with alkyl fluorides. From ET to SN2 reaction pathways and synthetic applications
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The reaction of dilithium biphenyl (Li2C12H10) with alkyl fluorides has been studied from the point of view of the distribution of products. Two main reaction pathways, the nucleophilic substitution (SN2) and the electron transfer (ET), can compete to yield the same alkylation products in what is known as the SN2-ET dichotomy. SN2 seems to be the main mechanism operating with primary alkyl fluorides (n-RF). Alkylation proceeds in good yields, and the resulting alkylated dihydrobiphenyl anion (n-RC12H10Li) can be trapped with a second conventional electrophile (E+) affording synthetically interesting dearomatized biphenyl derivatives (n-RC12H10E). The reaction gives a higher amount of ET products as we move to secondary (s-RF) and to tertiary alkyl fluorides (t-RF), in which case the mechanism seems to be dominated by ET. In this case, alkylation by radical coupling is still feasible, giving access to the synthesis of t-RC12H10E, although in lower yields. A rational interpretation of this SN2-ET dichotomy is given on the basis of the full distribution of products observed when 5-hexenyl fluoride and 1,1-dimethyl-5-hexenyl fluoride were are used as radical probes in their reaction with Li2C12H10 and LiC12H10.
- Pérez, Henoc,Melero, Cristóbal,Guijarro, Albert,Yus, Miguel
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experimental part
p. 10769 - 10783
(2010/02/28)
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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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- 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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p. 1311 - 1317
(2007/10/03)
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- Reductive Alkylation and Reduction of Tertiary, Secondary, and Benzylic Alcohols with Trimethyl-, Triethyl-, and Triisopropylboron/Trifluoromethanesulfonic (Triflic) Acid
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Tertiary, secondary, and benzylic alcohols were reductively alkylated and reduced with trimethyl-, triethyl-, and triisopropylboron/trifluoromethanesulfonic (triflic) acid.A postulated mechanism for the reactions is discussed.
- Olah, George A.,Wu, An-hsiang,Farooq, Omar
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p. 2759 - 2761
(2007/10/02)
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- Cross-Coupling Reaction of tert-Alkyl halides with Grignard Reagents in Dichloromethane as a Non-Lewis Basic Medium
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In dichloromethane as a non-Lewis basic solvent, 1-haloadamantane 1 underwent a cross-coupling reaction with Grignard reagents to give bridgehead-substituted products 3-16 in moderate yields.In this case the same kind of halogen in both 1 and a Grignard reagent was favored; if not, functional exchange (i.e., 1a to 1c) occurred first.The reaction using 5-hexenylmagnesium bromide as a radical probe afforded uncyclized/cyclized coupling products in a 6/4 ratio.These fact suggested the significant participation of the single-electron-transfer process in these reactions.The present method could be extended to tert-butylation with some Grignard reagents.Interestingly, 1,3-dichloro-3-methylbutane coupled with butylmagnesium chloride selectively at the tertiary position. for the above displacement reaction of 1, an organozinc was also found to be effective.
- Ohno, Masatomi,Shimizu, Kazuo,Ishizaki, Kenichi,Sasaki, Tadashi,Eguchi, Shoji
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p. 729 - 733
(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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- Superacid-Catalyzed Alkylation of Adamantane with Olefins
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The superacid catalyzed alkylation of adamantane with lower olefins (ethene, propene, and butenes) was investigated.Alkyladamantanes obtained show that the reaction occurs by two pathways: (a) adamantylation of olefins by adamantyl cation formed through hydride abstraction from adamantane by alkyl cations (generated by the protonation of the olefins) and (b) direct ?-alkylation of adamantane by the alkyl cations via insertion into the bridgehead C-H bond of adamantane through a pentacoordinate carbonium ion.
- Olah, George A.,Farooq, Omar,Krishnamurthy, V. V.,Prakash, G. K. Surya,Laali, Khosrow
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p. 7541 - 7545
(2007/10/02)
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- Selective Cleavage of Carbon-Nitrogen Bonds with Platinum
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The selective hydrogenolysis of carbon-nitrogen bonds relative to carbon-carbon bonds with a heterogeneous platinum catalyst is studied on a wide variety of nitrogen-containing organic molecules.Nitriles, secondary and primary amines, nitro compounds, heterocycles, and aromatic amides are cleanly converted to the parent hydrocarbon and ammonia in the gas phase with a platinum on silica catalyst and hydrogen.Aliphatic amides pass the catalyst unchanged.Unusual is the high platinum content of the catalyst (40percent) which proved to be essential for the catalytic activity reported.
- Guttieri, Mary J.,Maier, Wilhelm F.
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p. 2875 - 2880
(2007/10/02)
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- Structure-Anti-Parkinson Activity Relationships in the Aminoadamantanes. Influence of Bridgehead Substitution
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A limited series of bridgehead alkyl-, dialkyl- and trialkyl-substituted amantadines was synthesized and tested for potential anti-Parkinson activity as dopamine (DA) agonists.The compounds were evaluated using a battery of three murine bioassays, including stimulation of locomotor activity, induction of circling in animals with unilateral striatal lesions, and reversal of reserpine/α-methyltyrosine induced akinesia.Apparent mechanistic differences were seen between the methyl-substituted series and the ethyl-substituted series.While activities in both series increase with increasing liphophilicity, the methyl series (1b-d), as well as amantadine itself (1a) exhibits only indirect DA agonist activity, as evidenced by ipsilateral rotation in the circling model and no significant difference from control in reversal of akinesia.The ethyl series (1e,f) exhibits weak but reprodicible direct DA agonist activity, as shown by contralateral rotation in the circling assay for 1e and reversal of akinesia by 1e and 1f.The 3-n-propyl derivative (1g) was devoid of any DA agonist activity.
- Henkel, James G.,Hane, Jeffrey T.,Gianutsos, Gerald
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- Hydrogenolysis of Alkyl-Substituted Adamantanes, Diamantanes, and Triamantanes in the Gas Phase on a Nickel-Alumina Catalyst
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Dealkylation of several alkyladamantanes, diamantanes, and triamantanes has been observed in the gas phase with hydrogen at atmospheric pressure on a 30percent nickel-alumina catalyst.Yield-temperature profiles show that the optimum temperature for obtaining the pure parent compound in high yield can be as low as 215 deg C.The ease of removal of an alkyl substituent depends on whether it is secondary or tertiary on the diamondoid nucleus.Rupture of the diamondoid skeleton requires much higher temperatures (over 280 deg C) than dealkylation.The hydrogenolytic degradation of diamantane to adamantane was examined with the aid of molecular mechanics calculations; likely pathways for C-C bond cleavage were deduced which are consistent with the several intermediates detected experimentally.The mechanism of dealkylation is discussed in terms of steric and thermodynamic factors and the nature of possible surface intermediates.*
- Grubmueller, Peter,Maier, Wilhelm F.,Raque Schleyer, Paul von,McKervey, M. Anthony,Rooney, John J.
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p. 1989 - 2006
(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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