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Allylation
Kinds of Allylation Terms modified by Allylation Selected AbstractsEnantioselective Ag-Catalyzed Allylation of Aldimines,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 30 2009Marina Naodovic Abstract A highly enantioselective synthesis of homoallylic amines, using allyltrimethoxysilane under AgI catalytic conditions, has been developed. Among the chiral ligands investigated, a remarkable difference in the resulting AgI complexes was observed. Under mild conditions and low catalyst loadings, homoallylamines were produced in high ee values (up to 80,%) and good yields. The methodology can be further extended to a diastere- and enantioselective crotylation of aldimines.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Highly Selective Preparation of a Chiral Quaternary Allyl Aryl Piperidinedione by Palladium-Catalyzed Asymmetric Allylation Under Solid,Liquid Phase-Transfer CatalysisEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 36 2007Audrey Nowicki Abstract The combination of a chiral palladium catalyst and a solid,liquid phase-transfer catalyst provides an effective method for the chemo- and enantioselective preparation of the chiral quaternary center of an allyl aryl piperidinedione. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Bismuth Triflate Catalyzed Allylation of Aldehydes with Allylstannane under Microwave Assistance,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2007Thierry Ollevier Abstract In the presence of a catalytic amount of bismuth triflate and under microwave irradiation, mixtures of aldehyde and allylstannane afforded smoothly the corresponding homoallylic alcohol. A wide variety of aldehydes were treated under these conditions. The reactions proceeded rapidly and afforded smoothly the corresponding homoallylic alcohol in good to very good yields using catalytic amounts of Bi(OTf)3·4H2O (0.5 mol-%) and under microwave irradiation for a short time.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Palladium-Catalyzed Allylation of Pronucleophiles with Alkynes at 50 °C , Remarkable Effect of 2-(Dicyclohexylphosphanyl)-2,-(dimethylamino)biphenyl as LigandEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2006Nitin T. Patil Abstract The allylation of various pronucleophiles 1a,i with 1-phenylprop-1-yne (2) proceeded very smoothly at 50 °C in the presence of catalytic amounts of Pd2(dba)3·CHCl3 (5 mol-%) and 2-(dicyclohexylphosphanyl)-2,-(dimethylamino)biphenyl (I; 20 mol-%) in toluene, whilst when Pd(PPh3)4 or Pd2(dba)3·CHCl3/PPh3 were used, the reaction needed 100 °C for completion.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Highly Enantio- and Diastereoselective One-Pot Reactions in Aqueous Media: Combined Asymmetric Rh-Catalyzed Conjugate Addition/Metal-Mediated AllylationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2006Sara Källström Abstract 1,3-Disubstituted, enantiopure cyclohexanols have been prepared in very high diastereoselectivities and good yields by a concise one-pot method combining the enantioselective rhodium-catalyzed conjugate addition of arylboronic acids with indium-mediated allylation into a highly efficient one-pot reaction in aqueous media. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Allylation of Aldehyde and Imine Substrates with In Situ Generated Allylboronates , A Simple Route to Enatioenriched Homoallyl AlcoholsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2005Sara Sebelius Abstract Allylation of aldehyde and imine substrates was achieved using easily available allylacetates and diboronate reagents in the presence of catalytic amounts of palladium. This operationally simple one-pot reaction has a broad synthetic scope, as many functionalities including, acetate, carbethoxy, amido and nitro groups are tolerated. The allylation reactions proceed with excellent regio- and stereoselectivity affording the branched allylic isomer. By employment of commercially available chiral diboronates enantioenriched homoallyl alcohols (up to 53,% ee) could be obtained. The mechanistic studies revealed that the in situ generated allylboronates react directly with the aldehyde substrates, however the allylation of the sulfonylimine substrate requires palladium catalysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Asymmetric Synthesis of ,,,-Substituted ,-Sultones via Allylation of Chiral Lithiated SulfonatesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2003Dieter Enders Abstract The first auxiliary controlled asymmetric synthesis of enantiopure ,,,-substituted ,-sultones via ,-allylation of lithiated sulfonates by using 1,2:5,6-di- O -isopropylidene-,- D -allofuranose as chiral auxiliary is described. The high asymmetric inductions of the ,-allylations were reached in good to excellent yields. Successive epimerization-free cleavage of the auxiliary and diastereoselective ring closure of the sulfonic acid intermediates in a one-pot procedure led to the title compounds in good to excellent yields and diastereo- and enantiomeric excesses (de, ee , 98%). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Diastereoselective Zinc-Mediated Barbier-Type Allylation and Propargylation of 3-FormylcephalosporinsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2003Rolf Keltjens Abstract We describe the allylation and propargylation of 3-formylcephalosporins under zinc-mediated, aqueous Barbier conditions, from which the corresponding homoallylic alcohols are produced in good yields and with good-to-excellent diastereoselectivity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Allylation of aldiminomercaptotriazinones using allyl halides and allylmetal compoundsHETEROATOM CHEMISTRY, Issue 3 2003Ashraf A. El-Shehawy Allylation of 4-amino-3-mercapto-6-methyl-4H -1,2,4-triazin-5-one (1) and its arylideneamino derivatives 5 was performed through two different methods. Reaction of 1 and 5 with allylic bromides 2 in the presence of sodium ethoxide afforded a mixture of S - and N -allylated products. Treatment of arylimines 5 with allylic zinc bromides 9 and triallylborane reagents 12 did not affect the hetero-ring opening but the CN bond of the lateral chain underwent the addition reaction yielding the C -allylated products 10. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:280,287, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10144 [source] Catalytic Use of a Soluble Organoindium(III) Species for Allylation and Crotylation of Ketones with BoronatesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010Miyuki Yamaguchi Abstract The unprecedented use of a soluble organoindium species, indium(III) hexamethyldisilazide [In(III)(hmds)3], for catalytic carboncarbon bond formations between ketones and boronates, is reported. Various functionalized tertiary homoallyl alcohols were generated easily in high yields. Remarkably, free hydroxy and primary amine functionalities proved to be tolerated. A rate acceleration and markedly improved diastereoselectivities were observed in the presence of methanol. Based on preliminary NMR experiments and the ,-selectivity with an ,-substituted boronate, we assume the in situ generation of reactive allylindium(III) species through catalytic boron-to-indium transmetalation. [source] ,- and ,-Stannyl Trifluoromethylbutenoates: Regioselective Preparation and Use in Copper(I)-Catalyzed Allylation and Propargylation ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Yvan Carcenac Abstract The palladium-free hydrostannylation of ethyl 4,4,4-trifluorobutynoate 1 with tributyltin hydride at room temperature is highly regio- and stereoselective, providing good yields of ,-trifluoromethyl (Z)-,- or (Z)-,-stannylacrylates 2. Vinylstannanes 2 undergo a copper(I)-catalyzed coupling reactions with allylic or propargylic bromides leading selectively to good yields of the corresponding allylated or propargylated products without allylic or allenic transposition. [source] A Spirocyclic Chiral Borate for Catalytic Enantioselective Nozaki-Hiyama Allylation of KetonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Xin-Ren Huang Abstract A new class of chiral spirocyclic borate ligands 5a,d with a rigid borocycle has been developed. The catalyst formed from chromium(II)- 5a promotes the highly efficient enantioselective Nozaki,Hiyama allylation of alkyl and aryl ketones using allyl bromide. The scope of the present method is shown to be wide, and it affords an efficient access to chiral tertiary homoallylic alcohols. [source] Cationic Ruthenium-Cyclopentadienyl-Diphosphine Complexes as Catalysts for the Allylation of Phenols with Allyl Alcohol; Relation between Structure and Catalytic Performance in O - vs.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009C -Allylation Abstract A new catalytic method has been investigated to obtain either O - or C -allylated phenolic products using allyl alcohol or diallyl ether as the allyl donor. With the use of new cationic ruthenium(II) complexes as catalyst, both reactions can be performed with good selectivity. Active cationic Ru(II) complexes, having cyclopentadienyl and bidentate phosphine ligands are generated from the corresponding Ru(II) chloride complexes with a silver salt. The structures of three novel (diphosphine)Ru(II)CpCl catalyst precursor complexes are reported. It appears that the structure of the bidentate ligand has a major influence on catalytic activity as well as chemoselectivity. In addition, a strong cocatalytic effect of small amounts of acid is revealed. Model experiments are described that have been used to build a reaction network that explains the origin and evolution in time of both O -allylated and C -allylated phenolic products. Some mechanistic implications of the observed structure vs. performance relation of the [(diphosphine)RuCp]+ complexes and the cocatalytic role of added protons are discussed. [source] Simple and Fast Synthesis of New Axially Chiral Bipyridine N,N, -Dioxides for Highly Enantioselective Allylation of AldehydesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Aneta Kadl, íková Abstract Unsymmetrically 3,3,-substituted axially chiral bis(tetrahydroisoquinoline) N,N,- dioxides can be prepared in just three steps. They exhibit unique catalytic activity (turnover frequency, enantioselectivity, substrate scope) in the asymmetric allylation of aromatic aldehydes (up to 96% ee). The product of the enantioselective allylation of benzaldehyde served as a building block for the preparation of an intermediate useful in the enantioselective synthesis of diospongines. [source] Mild and Efficient Allylation of Aldehydes by using Copper Fluorapatite as CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2008M. Lakshmi Kantam Abstract A facile synthesis of homoallylic alcohols is achieved by the allylation of aldehydes with allylic metal reagents or allyl halides using copper fluorapatite (CuFAP) as catalyst under mild reaction conditions. A variety of aldehydes were converted to the corresponding homoallylic alchohols, demonstrating the versatility of the reaction. [source] Highly Enantioselective Allylation of Aromatic ,-Keto Phosphonates Catalyzed by Chiral N,N,- Dioxide-Indium(III) ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2 2008Jinglun Huang Abstract The ramipril derivative N,N, -dioxide 3g -indium(III) complex was found to be an efficient catalyst for the allylation of the aromatic ,-keto phosphonates. The corresponding ,-hydroxy phosphonates were obtained with high yields (up to 98,%) and high enantioselectivities (up to 91,% ee). A bifunctional catalyst system was described with an N -oxide as Lewis base activating tetraallyltin and indium as Lewis acid activating aromatic ,-keto phosphonates. A possible catalytic cycle has been proposed to explain the mechanism of the reaction. [source] Layered Double Hydroxide Supported Nanoplatinum and Nanopalladium Catalyzed Allylation of Aldehydes: A Mechanistic StudyADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 15 2005M. Choudary Abstract Layered double hydroxide (LDH)-supported nanoplatinum(0) and nanopalladium(0) catalysts were prepared by a simple ion exchange technique and subsequent reduction with hydrazine hydrate and used for the allylation of aldehydes to give moderate to good yields of homoallylic alcohols. Detailed mechanistic studies of LDH-Pd(0)-catalyzed allylation using XPS and TGA-MS reveal that a monoallyl-palladium complex is the key intermediate for the catalytic cycle. [source] Allylation of Aldehydes Promoted by the Cerium(III) Chloride Heptahydrate/Sodium Iodide System: the Dependence of Regio- and Stereocontrol on the Reaction ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-13 2005G. Bartoli Abstract The cerium(III) chloride heptahydrate/sodium iodide complex (CeCl3,,,7,H2O/NaI) acts as a useful promoter in the carbon-carbon bond forming reaction by addition of allyltributylstannanes to aldehydes. The reaction of 2-butenyltributylstannane shows that the regio- and the stereochemical outcomes depend on the reaction conditions. When the promoter is adsorbed on a solid support (aluminum oxide), a highly prevalent formation of the ,-adduct is observed in solvent-free conditions. Conversely, when the reaction is carried out in acetonitrile as the solvent, the ,-adduct largely prevails. In the last case, a complete stereocontrol is observed, the less stable (Z)-isomer being obtained in high geometrical purity. [source] Indium(I)-Catalyzed Asymmetric Allylation, Crotylation, and ,-Chloroallylation of Hydrazones with Rare Constitutional and High Configurational Selectivities,ANGEWANDTE CHEMIE, Issue 10 2010Ananya Chakrabarti Dr. Tolerabel: Bei der ersten asymmetrischen Indium(I)-Katalyse erwies sich ein System aus InI und einem chiralen Semicorrin-Liganden (L*) als wirkungsvoller Katalysator für die enantioselektive Allylierung, Crotylierung und ,-Chlorallylierung von Hydrazonen. In den beiden zuletzt genannten Fällen verläuft die C-C-Verknüpfung hoch selektiv, ohne dass die reaktiven O-H- bzw. C-Cl-Bindungen angegriffen werden. pin=Pinakol. [source] Desymmetrization of meso -2-Alkene-1,4-diol Derivatives through Copper(I)-Catalyzed Asymmetric Boryl Substitution and Stereoselective Allylation of Aldehydes,ANGEWANDTE CHEMIE, Issue 3 2010Hajime Ito Prof. Schluss mit der Symmetrie: Die im Titel beschriebene Reaktionsfolge wurde in der Synthese einer wertvollen Wirkstoffvorstufe und zum raschen stereoselektiven Aufbau komplizierter Verbindungen mit mehreren Chiralitätszentren genutzt (siehe Schema). [source] ChemInform Abstract: Silver-Catalyzed Benzylation and Allylation of Tertiary Alkyl Bromides with Organozinc Reagents.CHEMINFORM, Issue 42 2010Yukihiro Mitamura Abstract Silver salts catalyze the benzylation and allylation of tertiary alkyl bromides with organozinc reagents. [source] ChemInform Abstract: Synthesis of 4-Allylquinazolines from N-(2-Cyanoaryl)amides via the In-Mediated Allylation of Nitrile and Dehydrative Cyclization Cascade.CHEMINFORM, Issue 36 2010Sung Hwan Kim Abstract The sequence yields 4-allylquinazolines (III) and (V). [source] ChemInform Abstract: Rapid Decarboxylative Allylation of Nitroalkanes.CHEMINFORM, Issue 27 2010Alexander J. Grenning Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Broensted Acid Ionic Liquid-Catalyzed Direct Benzylation, Allylation and Propargylation of 1,3-Dicarbonyl Compounds with Alcohols as well as One-Pot Synthesis of 4H-Chromenes.CHEMINFORM, Issue 3 2010Kazumasa Funabiki Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: From Allylic Alcohols to Chiral Tertiary Homoallylic Alcohol: Palladium-Catalyzed Asymmetric Allylation of Isatins.CHEMINFORM, Issue 46 2009Xiang-Chen Qiao Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: TfOH-Catalyzed Allylation of Alkynes with Cyclic Baylis,Hillman Alcohols.CHEMINFORM, Issue 41 2009Chen Wu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Asymmetric Allylation of Methyl Ketones by Using Chiral Phenyl Carbinols.CHEMINFORM, Issue 41 2009Lutz F. Tietze Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Yb[N(SO2C8F17)2] 3 -Catalyzed Allylation of 1,3-Dicarbonyl Compounds with Allylic Alcohols in a Fluorous Biphase System.CHEMINFORM, Issue 40 2009Ming-Gui Shen Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Complex Allylation by the Direct Cross-Coupling of Imines with Unactivated Allylic Alcohols.CHEMINFORM, Issue 36 2009Masayuki Takahashi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Catalytic Direct-Type Substitution Reaction of ,-Alkyl Enolates: A Pd/Broensted Base Catalyzed Approach to the Decarboxylation Allylation of Sulfonylimidates.CHEMINFORM, Issue 17 2009S. B. Jennifer Kan Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] | |||||||||||||||||||||||||