- Electrophilic Iron Catalyst Paired with a Lithium Cation Enables Selective Functionalization of Non-Activated Aliphatic C?H Bonds via Metallocarbene Intermediates
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Combining an electrophilic iron complex [Fe(Fpda)(THF)]2 (3) [Fpda=N,N′-bis(pentafluorophenyl)-o-phenylenediamide] with the pre-activation of α-alkyl-substituted α-diazoesters reagents by LiAl(ORF)4 [ORF=(OC(CF3)3] provides unprecedented access to selective iron-catalyzed intramolecular functionalization of strong alkyl C(sp3)?H bonds. Reactions occur at 25 °C via α-alkyl-metallocarbene intermediates, and with activity/selectivity levels similar to those of rhodium carboxylate catalysts. Mechanistic investigations reveal a crucial role of the lithium cation in the rate-determining formation of the electrophilic iron-carbene intermediate, which then proceeds by concerted insertion into the C?H bond.
- Hernán-Gómez, Alberto,Rodríguez, Mònica,Parella, Teodor,Costas, Miquel
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supporting information
p. 13904 - 13911
(2019/08/30)
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- Beta-ketoester compounds
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The beta-ketoesters of formula I are useful as precursors for organoleptic compounds, especially for flavors, fragrances and masking agents and antimicrobial compounds.
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Page column 13
(2010/11/30)
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- Beta-ketoester compounds
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The beta-ketoesters of formula I are useful as precursors for organoleptic compounds, especially for flavors, fragrances and masking agents and antimicrobial compounds.
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- Synthesis and pharmacology of 3-isoxazolol amino acids as selective antagonists at group I metabotropic glutamic acid receptors
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Using ibotenic acid (2) as a lead, two series of 3-isoxazolol amino acid ligands for (S)-glutamic acid (Glu, 1) receptors have been developed. Whereas analogues of (RS)-2-amino-3-(3-hydroxy- 5-methyl-4-isoxazolyl)propionic acid [AMPA, (RS)-3] interact sel
- Madsen,Br?uner-Osborne,Frydenvang,Hvene,Johansen,Nielsen,Sánchez,Stensb?l,Bischoff,Krogsgaard-Larsen
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p. 1051 - 1059
(2007/10/03)
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- Process for the preparation of pure alkyl alkylacetoacetates
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A process for the purification of alkyl alkylacetoacetates of the general formula: STR1 in which R1 is a C1 -C10 -alkyl group and R2 is a C1 -C4 -alkyl group. In the process, an alkyl alkylacetoacetate which contains an alkyl alkenylacetoacetate of the general formula: STR2 in which R1 and R2 have the above-stated meaning, and/or further by-products as an impurity, is converted with an ester of the general formula: STR3 in which R2 has the above-stated meaning, in the presence of a base, into an intermediate which is separated off.
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- Production of oxetanones
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The invention relates to a novel process for producing a compound having the formula STR1 wherein R1, R2 and X are described herein, via wherein R corresponding β-keto- and β-hydroxy-δ-lactones, as well as novel intermediates which occur in the process.
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- Cobalt(II)acetate promoted oxidative addition of 1,3-dicarbonyl compounds to alkenes under aerobic conditions
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The reaction of 1,3-dicarbonyl compounds with various alkenes in presence of Co(OAC)2. XH2O under aerobic conditions gives dihydrofurans in moderate to good yields. The role of dioxygen is discussed by comparing these reactions under
- Iqbal,Bhatia,Nayyar
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p. 6457 - 6468
(2007/10/02)
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- Stereoselective synthesis of substituted tetrahydrofurans - Identification and analysis by proton NMR and MNDO, MM2 calculations
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Methyl acetoacetate and terminal olefins react in the presence of cobalt(II) acetate and oxygen to give 5-alkyl-2-hydroxy-2-methyl-3-methoxycarbonyl tetrahydrofurans in a highly stereoselective manner. Proton NMR, semiempirical MNDO and empirical MM2 methods are used to identify the particular diastereomer and the energetics of the different isomers are discussed.
- Tarakeshwar,Iqbal, Javed,Manogaran
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p. 297 - 304
(2007/10/02)
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- COBALT(II) ACETATE PROMOTED ADDITION OF ACETOACETATE TO TERMINAL OLEFINS: A HIGHLY STEREOSELECTIVE SYNTHESIS OF 5-ALKYL-2-HYDROXY-2-METHYL-3-METHOXYCARBONYL TETRAHYDROFURANS
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Methylacetoacetate and terminal olefins react in presence of Cobalt(II) acetate and Oxygen to give the title compound(2) in a highly stereoselective manner and the structure of this compound is elucidated by 1H NMR simulation studies.
- Iqbal, Javed,Kumar, T. K. Praveen,Manogaran, S.
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p. 4701 - 4702
(2007/10/02)
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