Showing papers on "Alkylation published in 2000"
TL;DR: In this paper, the cross-coupling of aryl boronic acids and alkanethiols mediated by copper(II) acetate and pyridine in anhydrous dimethylformamide has been used for the synthesis of the sulfide of cysteine.
282 citations
TL;DR: In this paper, a benzene alkylation with ethene and propene has been carried out under liquid phase reaction conditions over zeolites MCM-22, Beta, and ZSM-5.
267 citations
Book•
01 Jan 2000
TL;DR: In this article, the authors proposed a method for the synthesis of aromatic rings using a mixture of methylene and ammonia, which they called Alkylation of Ammonia (Amination).
Abstract: ACETOXYLATION Ethylene + Acetic Acid a Vinyl Acetate Butadiene + Acetic Acid a 1,4 Diacetoxy-2-Butene a 1,4 Butanediol a Tetrahydrofuran Propylene + Acetic Acid a Allyl Acetate a Allyl Alcohol ALKYLATION Introduction Alkylation of Benzene and Toluene Alkylation of Phenols Higher Alkylphenols Alkylation of Polynuclear Aromatics Alkylation of Aromatic Amines Transalkylation and Disproportionation Lower Aliphatic Amines by Alkylation of Ammonia (Amination) AMMONOLYSIS Phenol + Ammonia a Aniline Meta-Cresol + Ammonia a Meta-Toludine Diethylene Glycol + Ammonia a Morpholine AMMOXIDATION Propylene a Acrylonitrile Methane a HCN Isobutylene a Methacrylonitrile Aromatic Methyl Compounds a Nitriles CARBONYLATION Carboxylation of Olefins to Carboxylic Acids Carbon Monoxide + Chlorine a Phosgene DEHYDRATION OF ALCOHOLS 1-Phenylethanol a Styrene DEHYDROCHLORINATION C10 - C13 Chloridea Linear Olefins DEHYDROGENATION Dehydrogenation of Ethylbenzene Styrene Derivatives from Other Alkyl Aromatics Dehydrogenation of Lower Alkanes Alcohols to Aldehydes or Ketones Three Other Dehydrogenations EXPOXIDATION Ethylbenzene a Propylene Oxide + Styrene HYDRATION Ethylene a Ethanol Propylene a Isopropyl Alcohol N-ButenesaSec-Butanol Acrylonitrile a Alkylamide HYDROCHLORINATION Alkenes Alcohols HYDROGENATION General Background Hydrogenation of Aromatic Rings Hydrogenation of Heterocyclic Compounds Hydrogenation of Aliphatic Unsaturates Hydrogenation of Nitriles to Amines Hydrogenation of Nitroaromatics Hydrogenation of Haloaromatics Hydrogenation of Carbonyl Compounds Hydrogenation of Resins, Rosins, and Waxes Selective Hydrogenation of Fats and Oils Miscellaneous Hydrogenations HYDROGENOLYSIS Natural Fatty Acids and Fatty Esters a Fatty Alcohols Dimethylterephthalate a 1,4 Dimethylolcyclohexane Toluene a Benzene (Hydroalkylation) Methyl and Dimethyl Napthalene ISOMERIZATION Meta-Xylene a Para and Ortho-Xylene OXIDATION (INORGANIC) Sulfur Dioxide a Sulfur Trioxide a Sulfuric Acid Ammonia a Nitric Oxide a Nitrogen Dioxide a Nitric Acid Hydfrogen Sulfide a Sulfur OXIDATION (ORGANICS) General Ethylene a Ethylene Oxide Propene a Acrolein Propene a Acrolein a Acrylic Acid Butane or Benzene a Maleic Anhydride Ortho-Xylene or Naphthalene a Phthalic Anhydride Anthracene a Anthraquinone Methanol a Formaldehyde Isobutylene or Tert-Butyl Alcohol a Methacrolein a Methacrylic Acid OXYCHLORINATION Ethylene a 1,2 Dichloroethane a Vinyl Chloride PETROLEUM REFINING Catalytic Reforming Hydroprocessing (General) Hydrotreating Hydrocracking Isomerization Oligomerization (Polymer Gasoline Production) Fluid Catalytic Cracking Oxygenates SYNTHESIS GAS AND ITS PRODUCTS Historical Background Modern Synthesis Gas Production High and Low Temperature Shift Conversion (CO + H2O a H2 + CO2) Naphtha Steam Reforming Methanol Synthesis (Carbon Monoxide + Hydrogen a Methanol) Pure Carbon Monoxide from Synthesis Gas and Its Uses Pure Hydrogen from Synthesis Gases and Its Uses Ammonia Synthesis (Nitrogen + Hydrogen a Ammonia) Appendix
253 citations
TL;DR: In this article, inert ionic liquids were used as acid catalysts for the alkylation of benzene, toluene, naphthalene, and phenol with dodecene.
251 citations
TL;DR: Friedel et al. as mentioned in this paper used 1,3-dialkylimidazolium salts with easy catalyst/solvent recycling for alkylation of aromatic compounds with alkenes.
186 citations
TL;DR: The reaction of 2-(1-naphthyl)-3-methylpyridine with olefins in the presence of [RhCl(coe)2]2 and PCy3 as the catalyst resulted in the alkylation of the 2-position in good yield as discussed by the authors.
Abstract: The reaction of 2-(1-naphthyl)-3-methylpyridine with olefins in the presence of [RhCl(coe)2]2 and PCy3 as the catalyst resulted in the alkylation of the naphthyl ring at the 2-position in good yield. The replacement of PCy3 with the chiral ferrocenyl phosphine, (R),(S)-PPFOMe, as the ligand resulted in atropselective alkylation of the naphthylpyridine derivatives. Ethylene reacted with the biaryl compounds to give the corresponding addition products in moderate yields with fair to good ee's (up to 49% ee).
171 citations
151 citations
150 citations
Eni1
TL;DR: The use of zeolitic catalysts in organic syntheses is reviewed with emphasis on recent developments in the areas of acid and redox catalysis and on their relationship with environmental issues as mentioned in this paper.
Abstract: The use of zeolitic catalysts in organic syntheses is reviewed with emphasis on recent developments in the areas of acid and redox catalysis and on their relationship with environmental issues. Examples of acid‐catalyzed reactions are chosen from the acylation, alkylation, hydroxyalkylation of aromatic and heterocyclic compounds and from rearrangement reactions. The epoxidation of olefins, the hydroxylation of arenes and the oxidation of O‐, S‐ and N‐functionalities with hydrogen peroxide on Ti‐zeolites illustrate catalyzed oxidations.
124 citations
TL;DR: The ruthenium-catalyzed oxidation of alkanes with tert-butyl hydroperoxide and peracetic acid gives the corresponding ketones and alcohols highly efficiently at room temperature.
Abstract: The ruthenium-catalyzed oxidation of alkanes with tert-butyl hydroperoxide and peracetic acid gives the corresponding ketones and alcohols highly efficiently at room temperature. The former catalytic system, RuCl2(PPh3)3-t-BuOOH, is preferable to the oxidation of alkylated arenes to give aryl ketones. The latter system, Ru/C−CH3CO3H, is suitable especially for the synthesis of ketones and alcohols from alkanes. The ruthenium-catalyzed oxidation of cyclohexane with CH3CO3H in trifluoroacetic acid/CH2Cl2 at room temperature gave cyclohexyl trifluoroacetate and cyclohexanone with 90% conversion and 90% selectivity (85:15). The mechanistic study indicates that these catalytic oxidations of hydrocarbons involve oxo−ruthenium species as key intermediates.
120 citations
TL;DR: The complex 12+ as discussed by the authors is a metal-containing analogue of 4,4′-bipyridine and undergoes N-alkylation reactions with a variety of alkylating agents to give more highly functionalised tetracationic complexes which may be termed metalloviologens.
Abstract: The complex 12+ which has two pendant 4-pyridyl substituents may be viewed as a metal-containing analogue of 4,4′-bipyridine. The complex undergoes N-alkylation reactions with a variety of alkylating agents to give more highly functionalised tetracationic complexes which may be termed metalloviologens by analogy with viologens. These complexes may also be prepared by alkylation of the free ligands and subsequent coordination of the pendant quaternised ligand. Structural studies have established that the N-alkylated complexes possess the correct spatial characteristics for the preparation of metallocycles analogous to known cyclic bis(4,4′-bipyridinium) species which possess useful molecular recognition properties.
TL;DR: In this article, secondary and tertiary alkylmagnesium chlorides were used successfully for the first time in such a reaction and ester, amide, nitrile or keto groups are tolerated.
TL;DR: In this article, a general method for carbocyclization of carbohydrates is described using two consecutive organometallic transformations: a novel zinc-mediated domino reaction to give functionalized dienes followed by ring-closing olefin metathesis.
Abstract: A general method for carbocyclization of carbohydrates is described using two consecutive organometallic transformations: a novel zinc-mediated domino reaction to give functionalized dienes followed by ring-closing olefin metathesis. In the first reaction, methyl ω-deoxy-ω-iodo glycosides undergo reductive elimination with zinc to produce a terminal double bond. This also liberates the aldehyde which is immediately alkylated in situ by various organozinc reagents. The alkylation occurs under Barbier conditions with methylene iodide and several allyl bromides. Zinc plays a dual role by both promoting the reductive elimination and activating the alkyl halide. Vinylation is carried out by adding divinylzinc. When a new stereogenic center is generated, moderate to excellent stereocontrol is generally observed. An amino group can be introduced by trapping the intermediate aldehyde as an imine prior to the alkylation. The reductive elimination−allylation sequence can also be promoted by indium metal. All the a...
TL;DR: Two different possibilities for the preparation of immobilised ionic liquids are presented in this article, and different methods used, as well as analytical data and some catalytical results achieved by these catalysts.
Abstract: Two different possibilities for the preparation of immobilised ionic liquids are presented. Lewis acidic ionic liquids which have been shown to be highly active catalysts in alkylation reactions of the Friedel–Crafts type were supported on amorphous silica and MCM 41 materials. We describe the different methods used, as well as analytical data and some catalytical results achieved by these catalysts.
TL;DR: The structure and the biological significance of naturally occurring and synthetic polyamine analogues and conjugates are presented and the available methodologies for their synthesis are described.
TL;DR: In this paper, an enone is exposed to a catalytic quantity of [CuH(PPh3)]6 in the presence of one of several silyl hydrides (PhMe2SiH, PMHS, HMe2SiOSiMe2H) leading to conjugate reduction with concomitant formation of the corresponding silyls enol ether.
TL;DR: A variety of highly enantioenriched singly and doubly functionalized derivatives of 1,1'-N,N, N,N',N'-tetraisopropylferrocenedicarboxamide 1 have been synthesized by (-)-sparteine (2)-mediated directed ortho-metalation and Pd-catalyzed cross coupling reactions.
TL;DR: The diastereoselective alkylation of glycolate oxazolidinones has been demonstrated as a method for the enantioselectives preparation of alpha-alkoxy carboxylic acid derivatives and selectively protected 1,2-diols.
TL;DR: In this article, the authors reported the joint application of ab initio computations and total synthesis to assign the absolute configuration of a new natural product, and the expected specific specific rotations of the (7S,10R)- and (7R, 10R)-isomers of pitiamide A in a CHCl3 solvent continuum model were determined as +8 and −39, respectively, by CADPAC calculations of the electric-dipole−magnetic-dispole polarizability tensor.
Abstract: We report the joint application of ab initio computations and total synthesis to assign the absolute configuration of a new natural product. The expected specific rotations of the (7S,10R)- and (7R,10R)-isomers of pitiamide A in a CHCl3 solvent continuum model were determined as +8 and −39, respectively, by CADPAC calculations of the electric-dipole−magnetic-dipole polarizability tensor. Total syntheses of these two stereoisomers of the marine metabolite were achieved by a convergent strategy that utilized Evans' oxazolidinone alkylation, a novel water-accelerated modification of Negishi's zirconocene-catalyzed asymmetric carbometalation as well as an unusual segment condensation via Mitsunobu alkylation of a nosyl-activated amide. The experimental optical rotation measurements confirmed the results of the computational optical rotation predictions. On the basis of NMR comparisons, the configuration of pitiamide A was assigned as (7R,10R). These studies highlight the considerable structural significance o...
TL;DR: Trivalent-iron-substituted mesoporous molecular sieve catalysts (FeMCM-41) were synthesized hydrothermally and characterized systematically by various analytical and spectroscopic techniques as mentioned in this paper.
Abstract: Trivalent-iron-substituted mesoporous molecular sieve catalysts (FeMCM-41) were synthesized hydrothermally and characterized systematically by various analytical and spectroscopic techniques. Temperature-programmed desorption studies of ammonia of the protonated catalyst (H–FeMCM-41) indicate a broad distribution of the acid sites. Vapour-phase alkylation of phenol with t-butyl alcohol (2-methyl-2-propanol) was carried out over this solid acid catalyst and p-t-butyl phenol was obtained as the major product with high selectivity.
TL;DR: The bis(iminophosphorano)methanediide (carbene) complexes [MCl2{C(Ph2PNSiMe3)2-κC,κ2N,N'} as discussed by the authors form Lewis acid−base adducts with THF, nitriles, and isonitriles and undergo 1,2-addition reactions with amines, alcohols, and alkyl iodides and [2 + 2]-cycloaddition reaction with heteroallenes.
TL;DR: In this paper, a general one-pot synthesis of unsymmetrically disubstituted difluoroolefins by the introduction of diffluorovinylidene unit as an ambiphile (CF2C−+) is presented.
TL;DR: In this article, the title compounds are made readily accessible by a catalytic procedure, occurring under mild conditions, based on palladium-mediated ortho alkylation of aromatic iodides with alkyl bromides followed by reaction with arylboronic acids.
TL;DR: Cinchonidine and cinchonine have been N -alkylated with Merrifield resin and employed as chiral phase-transfer catalysts for the enantioselective alkylation of enolates from N -(diphenylmethylene)glycine esters with activated electrophiles as discussed by the authors.
Abstract: Cinchonidine and cinchonine have been N -alkylated with Merrifield resin and employed as chiral phase-transfer catalysts for the enantioselective alkylation of enolates from N -(diphenylmethylene)glycine esters with activated electrophiles (up to 90% ee ). The use of the polymer-supported cinchonidine ammonium salt afforded the corresponding ( S )-isomers, whereas the ( R )-isomers were obtained using related cinchonine-supported polymers.
TL;DR: The synthesis of several omega-chloroalkyl tetrazoles and their subsequent attachment to a solid support is described and a sample library of 5 x 6 demonstrates the general utility of this sequence.
Abstract: The synthesis of several ω-chloroalkyl tetrazoles and their subsequent attachment to a solid support is described. Using an in situ Finkelstein reaction, a variety of nucleophiles were alkylated and then cleaved from the resin to give pure alkyl tetrazole derivatives. A sample library of 5 × 6 demonstrates the general utility of this sequence.
TL;DR: In this paper, the acid-induced dealkyation reaction was used to remove the 1,1,3,3-tetramethylbutyl group derived from the isonitrile input.
TL;DR: In this paper, rare earth metal trifluoromethanesulfonates (RE(OTf)3) were found to be efficient catalysts for Friedel-Crafts acylation and alkylation.
Abstract: Rare earth metal trifluoromethanesulfonates (rare earth metal triflates, RE(OTf)3) were found to be efficient catalysts for Friedel-Crafts acylation and alkylation. In the presence of a catalytic amount of RE(OTf)3, acylation of aromatic compounds having electron-donating substituents such as anisole, thioanisole, and mesitylene with acid anhydrides proceeded smoothly to afford the corresponding aromatic ketones in high yields. Although RE(OTf)3 alone is not effective for acylation of less reactive aromatics such as toluene, the combination of RE(OTf)3 and lithium perchlorate (LiClO4) enhanced the catalytic activity dramatically. Friedel-Crafts acylation reactions using rare earth metal perfluoroalkanesulfonates were also successfully performed in supercritical carbon dioxide (scCO2). Moreover, in the presence of a catalytic amount of RE(OTf)3, aromatic compounds reacted with benzyl chloride smoothly to afford the corresponding alkylation products in high yields. In these reactions, RE(OTf)3 could be easi...