- Regioselective Halogenation of Arenes and Heterocycles in Hexafluoroisopropanol
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Regioselective halogenation of arenes and heterocycles with N-halosuccinimides in fluorinated alcohols is disclosed. Under mild condition reactions, a wide diversity of halogenated arenes are obtained in good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of one-pot sequential halogenation and halogenation-Suzuki cross-coupling reactions.
- Tang, Ren-Jin,Milcent, Thierry,Crousse, Benoit
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p. 930 - 938
(2018/01/28)
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- Examination of Selectivity in the Oxidation of ortho- and meta-Disubstituted Benzenes by CYP102A1 (P450 Bm3) Variants
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Cytochrome P450 CYP102A1 (P450 Bm3) variants were used to investigate the products arising from the P450 catalysed oxidation of a range of disubstituted benzenes. The variants used all generated increased levels of metabolites compared to the wild-type enzyme. With ortho-halotoluenes up to six different metabolites could be identified whereas the oxidation of 2-methoxytoluene generated only two aromatic oxidation products. Addition of an ethyl group markedly shifted the selectivity for oxidation to the more reactive benzylic position. Epoxidation of an alkene was also preferred to aromatic oxidation in 2-methylstyrene. Significant minor products arising from the migration of one substituent to a different position on the benzene ring were formed during certain P450-catalysed substrate turnovers. For example, 2-bromo-6-methylphenol was formed from the turnover of 2-bromotoluene and the dearomatisation product 6-ethyl-6-methylcyclohex-2,4-dienone was generated from the oxidation of 2-ethyltoluene. The RLYF/A330P variant altered the product distribution enabling the generation of certain metabolites in higher quantities. Using this variant produced 4-methyl-2-ethylphenol from 3-ethyltoluene with ≥90 % selectivity and with a biocatalytic activity suitable for scale-up of the reaction.
- Munday, Samuel D.,Dezvarei, Shaghayegh,Lau, Ian C.-K.,Bell, Stephen G.
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p. 2512 - 2522
(2017/07/12)
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- 1,2-asymmetric induction in diastereoselective zwitterionic aza-Claisen rearrangements: Key steps in optically active alkaloid synthesis
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The zwitterionic aza-Claisen rearrangement of optically active N-allylpyrrolidines and α-phenoxyacetyl fluorides proceeds with complete simple diastereoselectivity (internal asymmetric induction) and complete 1,2-asymmetric induction to generate a new C-C bond adjacent to a chiral C-N-Boc functionality. The resulting γ,δ-unsaturated amides were cyclised to give the corresponding pyrrolizidinones, which enabled the determination of the relative configuration of the stereotriads. Vinyl group degradation and a final lactam reduction gave an optically active analogue of (+)-petasinine (a pyrrolizidine alkaloid). Furthermore, the stereotriad-containing amides should be useful key intermediates for the total synthesis of optically active elaeocarpin (an indolizidine alkaloid). Copyright
- Heescher, Carolin,Schollmeyer, Dieter,Nubbemeyer, Udo
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supporting information
p. 4399 - 4404
(2013/07/26)
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- Copper-catalyzed cross-coupling interrupted by an opportunistic smiles rearrangement: An efficient domino approach to dibenzoxazepinones
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Unexpected Smiles! An unusual and highly regioselective synthesis of dibenzoxazepinones by a domino sequence assisted by an unexpected Smiles rearrangement is reported. The process is effective on electronically differentiated phenols and shows a high tolerance to variation in the benzamide substituents. A plausible path for the reaction, supported by preliminary mechanistic data, is offered. Copyright
- Kitching, Matthew O.,Hurst, Timothy E.,Snieckus, Victor
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p. 2925 - 2929
(2012/05/04)
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- Design of living ring-opening alkyne metathesis
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It's alive: A ring-strained alkyne based on dibenzo[a,e][8]annulene undergoes ringopening metathesis polymerization (ROMP) to give a high-molecular-weight poly(ortho-phenylene) featuring alternating ethyl and ethynyl linkers along the polymer backbone. The molybdenumalkylidyne- based catalyst system discriminates between strained and unstrained alkynes to yield a living polymer with an unparalleled low polydispersity.
- Fischer, Felix R.,Nuckolls, Colin
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supporting information; experimental part
p. 7257 - 7260
(2010/11/05)
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- An efficient, rapid, and regioselective bromination of anilines and phenols with 1-butyl-3-methylpyridinium tribromide as a new reagent/solvent under mild conditions
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1-Butyl-3-methylpyridinium tribromide, [BMPy]Br3 proves to be a highly efficient, regioselective reagent/solvent for nuclear bromination of various anilines and phenols. The synthesis and characterization of the room temperature ionic liquid [BMPy]Br3 (2) is described. The bromination was carried out in the absence of organic solvents and in most cases the only extraction solvent needed was water. The spent 1-butyl-3-methylpyridinium bromide (1) was easily recycled.
- Borikar, Sanjay P.,Daniel, Thomas,Paul, Vincent
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scheme or table
p. 1007 - 1009
(2009/05/11)
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- INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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Compounds of formula (I): wherein R4, R6 and R7 are defined herein, are useful as inhibitors of HIV replication.
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Page/Page column 60-61
(2009/06/27)
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- INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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Compounds of formula (I): wherein c, X, Y, R2, R4 and R5 are defined herein, are useful as inhibitors of HIV replication.
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Page/Page column 70
(2009/06/27)
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- INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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The present invention relates to compounds of formula (I) wherein c, X, Y, R2, R3, R4 and R6 are as defined herein, compositions and uses thereof for treating human immunodeficiency virus (HIV) infection. In particular, the present invention provides novel inhibitors of HIV integrase, pharmaceutical compositions containing such compounds and methods for using these compounds in the treatment of HIV infection
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Page/Page column 67
(2009/06/27)
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- INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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Compounds of formula I : wherein c, R2, R3, R4, R5, R6, R7 and R8 are defined herein, are useful as inhibitors of HIV replication.
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Page/Page column 74
(2009/06/27)
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- A practical highly selective oxybromination of phenols with dioxygen
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A simple, low cost and highly selective method for the synthesis of mono-bromophenols from phenol and electron-rich phenolic compounds has been developed. Bromide ions are used as halogenating agents, dioxygen as a final oxidant, and Cu(OAc)2 as a catalyst.
- Menini, Luciano,Parreira, Luciana A.,Gusevskaya, Elena V.
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p. 6401 - 6404
(2008/02/12)
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- Synthesis of substituted 2-bromo phenols using a novel bromination-dehydrobromination reaction
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Substituted 2-bromo-phenols can be synthesised by heating substituted cyclohexanones in neat diethyl dibromomalonate at 100°C. We discuss the efficiency of such a procedure and comment on the possible mechanism.
- Coumbarides,Dingjan,Eames,Weerasooriya
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p. 328 - 329
(2007/10/03)
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- N-Bromosuccinimide as a Regioselective Nuclear Monobrominating Reagent for Phenols and Naphthols
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A wide range of substituted phenols and naphthols were regioselectively monobrominated with N-bromosuccinimide, at para position in acetonitrile and at ortho position in carbon disulfide, under mild conditions in good yields. Methylphenols afforded only nuclear bromination products.
- Carre?o, M. Carmen,García Ruano, José L.,Sanz, Gema,Toledo, Miguel A.,Urbano, Antonio
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p. 1241 - 1242
(2007/10/03)
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