- Nickel-catalyzed carbon-carbon bond-forming reactions of unactivated tertiary alkyl halides: Suzuki arylations
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The first Suzuki cross-couplings of unactivated tertiary alkyl electrophiles are described. The method employs a readily accessible catalyst (NiBr2·diglyme/4,4′-di-tert-butyl-2,2′-bipyridine, both commercially available) and represents the initial example of the use of a group 10 catalyst to cross-couple unactivated tertiary electrophiles to form C-C bonds. This approach to the synthesis of all-carbon quaternary carbon centers does not suffer from isomerization of the alkyl group, in contrast with the umpolung strategy for this bond construction (cross-coupling of a tertiary alkylmetal with an aryl electrophile). Preliminary mechanistic studies are consistent with the generation of a radical intermediate along the reaction pathway.
- Zultanski, Susan L.,Fu, Gregory C.
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supporting information
p. 624 - 627
(2013/03/14)
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- METHOD FOR MANUFACTURING OPTICALLY ACTIVE MENTHOL
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An object of the present invention is to provide a method for manufacturing an optically active menthol having fewer steps, which generates less environmentally polluting waste because a catalytic reaction is involved in all of the steps, and is capable of saving a production cost. The present invention relates to a method for manufacturing an optically active menthol, including the following steps: A-1) asymmetrically hydrogenating at least one of geranial and neral to thereby obtain an optically active citronellal, B-1) conducting a ring-closure reaction of the optically active citronellal in the presence of an acid catalyst to thereby obtain an optically active isopulegol, and C-1) hydrogenating the optically active isopulegol to thereby obtain an optically active menthol.
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Paragraph 0436; 0437
(2013/10/07)
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- Carbon-based leaving group in substitution reactions: Functionalization of sp3-hybridized quaternary and tertiary benzylic carbon centers
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Lewis acid promoted substitution reactions employing Meldrum's acid and 5-methyl Meldrum's acid as carbon-based leaving groups are described which transform unstrained quaternary and tertiary benzylic Csp 3-Csp3 bonds into Csp3-X bonds (X = C, H, N). Importantly, this reaction has a broad scope in terms of both suitable substrates and nucleophiles with good to excellent yields obtained (typically >90%).
- Mahoney, Stuart J.,Lou, Tiantong,Bondarenko, Ganna,Fillion, Eric
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supporting information; experimental part
p. 3474 - 3477
(2012/09/05)
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- CATALYST FOR ASYMMETRIC HYDROGENATION
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This invention aims at providing a catalyst for producing an optically active aldehyde or an optically active ketone, which is an optically active carbonyl compound, by carrying out selective asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, particularly a catalyst which is insoluble in a reaction mixture for obtaining optically active citronellal which is useful as a flavor or fragrance, by carrying out selective asymmetric hydrogenation of citral, geranial or neral; and a method for producing a corresponding optically active carbonyl compound. The invention relates to a catalyst for asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, which comprises a powder of at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table, or a metal-supported substance in which at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table is supported on a support, an optically active cyclic nitrogen-containing compound and an acid.
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Page/Page column 51-52
(2010/12/31)
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- Selective alkylation of βII-tubulin and thioredoxin-1 by structurally related subsets of aryl chloroethylureas leading to either anti-microtubules or redox modulating agents
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Aryl chloroethylureas (CEUs) are potent anti-neoplastic agents alkylating specific intracellular proteins such as βII-tubulin. Recently we have identified a new subset of CEU derived from compound 36 that alkylates thioredoxin isoform 1 (Trx-1), inhibits the nuclear translocation of Trx-1, and favors the accumulation of cells in G0/G1 phase. We have evaluated the effects of various substituents and their position on the aromatic ring of a series of derivatives of 36 on (i) the anti-proliferative activity, (ii) the cell cycle progression, (iii) the nuclear translocation of Trx-1, and (iv) their covalent binding to β-tubulin. The same experiments were performed on representative CEU derivatives where the 2-chloroethyl amino moiety is replaced by either an ethyl, a 2-aminooxazolinyl or a 2-chloroacetyl group. On one hand, our results suggest that CEUs substituted on the phenyl ring at position 3 or 4 by cycloalkyl and substituted cycloalkyl or cycloalkoxy groups inhibit the nuclear translocation of Trx-1 and arrest the cell cycle progression in G0/G1. On the other hand, CEUs substituted by a fused aromatic ring, an aliphatic chain, or a fused aliphatic ring are alkylating βII-tubulin but not Trx-1. Beside the expected inactivity of the ethylurea derivatives, none of the modification to the electrophilic moiety led to cross-selectivity of the drugs toward β-tubulin but increased the anti-proliferative activity and resulted in mitigated effects on Trx-1 translocation.
- Fortin, Jessica S.,Cote, Marie-France,Lacroix, Jacques,Desjardins, Michel,Petitclerc, Eric,C.-Gaudreault, Rene
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p. 7277 - 7290
(2008/12/22)
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- Traction drive fluid
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A traction drive fluid is provided containing a naphthenic compound represented by the formula: wherein R1is an alkyl group having 1 to 8 carbon atoms, R2through R4are each independently hydrogen or an alkyl group having 1
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Page/Page column 36
(2008/06/13)
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- Synthesis of Arylcycloalkanes from ω-Alkenyl Benzylselenides
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Arylcycloalkanes are produced from ω-alkenyl benzylselenides on reaction with alkyllithiums or on Lewis acid mediated electrophilic cyclisation.
- Krief, Alain,Kenda, Benoit,Barbeaux, Phillipe,Guittet, Eric
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p. 7177 - 7192
(2007/10/02)
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- Synthesis and evaluation of 4-alkylanilines as mammary tumor inhibiting aromatase inhibitors
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The 4-alkylanilines 1-20 were synthesized to elucidate the importance of the glutarimide moiety for the aromatase inhibiting activity of aminoglutethimide [3-(4-aminophenyl)-3-ethylpiperidine-2,6-dione, AG], the only non-steroidal aromatase inhibitor which is commercially available at present. The most interesting compounds were the (4-aminophenyl)cycloalkanes 4-6 (4, c-pentyl; 5, c-hexyl; 6, c-heptyl) and the 1-alkyl-1-(4-aminophenyl)cyclohexanes 1-3 (1, CH3; 2, C2H5; 3, n-C3H7). Derivatives 1-6 are stronger inhibitors of human placental aromatase than AG exhibiting relative potencies from 1.5 to 2.7 (AG≡1). For selectivity of action, the inhibition of desmolase (cholesterol side chain cleavage enzyme) was determined. Compounds 1-3 showed an inhibition comparable to AG, whereas compounds 4-6 exhibited no effect on desmolase. Being more potent and selective aromatase inhibitors in vitro, compounds 4-6, however, were not superior to AG in vivo, when the reduction of plasma estradiol concentration and the tumor inhibiting activity (PMSG-primed SD rats and DMBA-induced mammary carcinoma of the SD rat, postmenopausal model) were concerned.
- Hartmann,Batzl
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p. 537 - 544
(2007/10/02)
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- ALKYLATION OF BENZENE WITH 4-METHYLCYCLOHEXANOL IN THE PRESENCE OF SULFURIC ACID
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Alkylation of benzene with 4-methylcyclohexanol in the presence of methylcyclohexane and 96, 88, and 80percent H2SO4 has been studied.It was established that depending on the solubility of the starting components in sulfuric acid, alkylation occurs in the inorganic phase or on the interface between the organic and inorganic phases.The yield and composition of the catalysate are determined to a significant degree by the extent of the alkylation process and intramolecular hydride transfers.
- Lipovich, V. G.,Zemskov, V. V.,Ratovskii, G. V.,Burlakova, O. V.
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p. 109 - 112
(2007/10/02)
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- REACTION OF 1-CHLORO-1-METHYLCYCLOHEXANE WITH PHENYL- AND BENZYL- TRIMETHYLSILANES IN THE PRESENCE OF ALUMINIUM CHLORIDE
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In the reaction of 1-chloro-1-methylcyclohexane with phenyltrimethylsilane and benzyltrimethylsilane in the presence of aluminum chloride the chlorine atom is substituted by a phenyl or benzyl group with the formation of 1-methyl-1-phenyl- and 1-methyl-1-benzylcyclohexane, respectively.In the case of benzyltrimethylsilane the products from alkylation of the benzene ring of the benzyltrimethylsilane by the 1-methylcyclohexyl carbocation in the Friedel-Crafts reaction are formed in addition to 1-methyl-1-benzylcyclohexane.
- Bolestova, G. I.,Parnes, Z. N.,Vol'pin, M. E.
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p. 967 - 971
(2007/10/02)
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