Home About us Contact
|
Home About us Contact | ||
|
|
||
Benzylic Alcohols (benzylic + alcohol)
Kinds of Benzylic Alcohols Selected AbstractsChemInform Abstract: FeCl3·6H2O Catalyzed Disproportionation of Allylic Alcohols and Selective Allylic Reduction of Allylic Alcohols and Their Derivatives with Benzylic Alcohol.CHEMINFORM, Issue 37 2009Jialiang Wang 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] Green, Palladium-Catalyzed Synthesis of Benzylic H -Phosphinates from Hypophosphorous Acid and Benzylic AlcoholsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2008Laėtitia Coudray Abstract Benzylic alcohols cross-couple directly with concentrated H3PO2 by using Pd/xantphos (1 or 2 mol-%). Depending on the substrate, DMF at 110 °C or t -AmOH at reflux with a Dean,Stark trap can be used. A broad range of benzylic alcohols react successfully to give moderate to good yields of the products. The preparation of other organophosphorus compounds (phosphinic and phosphonic acids) is also demonstrated. Asymmetric reaction with (R)-1-(2-naphthyl)ethanol provids the corresponding H -phosphinic acid in 77,% ee. The methodology provides a green, PCl3 -free route to benzylic- H -phosphinic acids.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Copper-Catalyzed N -Alkylation of Sulfonamides with Benzylic Alcohols: Catalysis and Mechanistic StudiesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Xinjiang Cui Abstract The N -alkylation of sulfonamides with alcohols is efficiently performed in the presence of easily available copper catalysts via hydrogen borrowing methodology. Applying a copper acetate/potassium carbonate system the reaction of sulfonamides and alcohols gave the corresponding secondary amines in excellent yield. In situ HR-MS analysis indicated that bissulfonylated amines are formed under air atmosphere, which act as self-stabilizing ligands for the catalytic system. UV-visible measurements suggest the interaction between the copper centre and the bissulfonylated amine. Reactions of benzyl alcohol- d7 with p -toluenesulfonamide, N -benzyl- p -toluenesulfonamide or N -benzylidenetoluenesulfonamide revealed that the reaction proceeds via a transfer hydrogenation mechanism and the whole process is micro-reversible. Competitive reactions of benzyl alcohol and benzyl alcohol- d7 with p -toluenesulfonamide revealed a kinetic isotope effect (kH/kD) of 3.287 (0.192) for the dehydrogenation of benzyl alcohol and 0.611 (0.033) for the hydrogenation of the N -benzylidene- p -toluenesulfonamide intermediate, which suggests that dehydrogenation of the alcohol is the rate-determining step. [source] Aerobic Oxidation of Benzylic Alcohols in Water by 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)/Copper(II) 2- N -Arylpyrrolecarbaldimino ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Abstract Novel copper(II) 2- N -arylpyrrolecarbaldimine-based catalysts for the aerobic oxidation of benzylic alcohols mediated by the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical are reported. The catalytic activity for both synthesized and in situ made complexes in alkaline water solutions was studied revealing high efficiency and selectivity (according to GC selectivity always >99%) for both of these catalytic systems. For example, quantitative conversion of benzyl alcohol to benzaldehyde can be achieved with the in situ prepared bis[2- N -(4-fluorophenyl)-pyrrolylcarbaldimide]copper(II) catalysts in 2,h with atmospheric pressure of O2 at 80,°C. Interestingly, these catalysts can utilize dioxygen as well as air or hydrogen peroxide as the end oxidants, producing water as the only by-product. [source] Trace Water-Promoted Oxidation of Benzylic Alcohols with Molecular Oxygen Catalyzed by Vanadyl Sulfate and Sodium Nitrite under Mild ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2009Zhongtian Du Abstract An inexpensive catalytic system consisting of vanadyl sulfate and sodium nitrite was developed for the oxidation of benzylic alcohols with molecular oxygen under mild conditions. Benzyl alcohols with various substitutions were efficiently converted to their corresponding aldehydes with high conversion and selectivity under 80,°C (e.g., 4-nitrobenzyl alcohol was smoothly oxidized to 4-nitrobenzyl aldehyde with 94% yield under 0.5,MPa of molecular oxygen). Halogen, noble metals, extra base or complicated ligands were avoided. Addition of a trace of water to this system before the reaction was crucial for the high efficiency. [source] ChemInform Abstract: Polyethylene Glycol Radical-Initiated Oxidation of Benzylic Alcohols in Compressed Carbon DioxideCHEMINFORM, Issue 48 2009Jin-Quan Wang 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: Ionic Liquid-H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPO.CHEMINFORM, Issue 32 2009Ruijun Hu 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: Oxidation of Secondary Benzylic Alcohols to Ketones by Activated Carbon,Molecular Oxygen System.CHEMINFORM, Issue 18 2008Yuki Sano 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] Facile and Selective Oxidation of Benzylic Alcohols to Their Corresponding Carbonyl Compounds with Sodium Nitrate in the Presence of Broensted Acidic Ionic Liquids.CHEMINFORM, Issue 34 2007Abdol R. Hajipour 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, please click on HTML or PDF. [source] Tandem Oxidation of Allylic and Benzylic Alcohols to Esters Catalyzed by N-Heterocyclic Carbenes.CHEMINFORM, Issue 20 2007Brooks E. Maki 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, please click on HTML or PDF. [source] Efficient and Selective Oxidation of Benzylic Alcohols to Carbonyl Compounds Using O2 Catalyzed by [nBu4N]4W10O32/SiO2 under Photoirradiation.CHEMINFORM, Issue 31 2006Saeid Farhadi 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, please click on HTML or PDF. [source] Cross-Coupling of Benzylic Acetates with Arylboronic Acids: One-Pot Transformation of Benzylic Alcohols to Diarylmethanes.CHEMINFORM, Issue 14 2006Ryoichi Kuwano 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, please click on HTML or PDF. [source] Photocatalytic Oxidation of Primary and Secondary Benzylic Alcohols to Carbonyl Compounds Catalyzed by H3PW12O40/SiO2 under an O2 Atmosphere.CHEMINFORM, Issue 12 2006Saeid Farhadi 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, please click on HTML or PDF. [source] Selective Oxidation of Benzylic Alcohols and TBDMS Ethers to Carbonyl Compounds with CrO3,H5IO6.CHEMINFORM, Issue 46 2005Suhong Zhang Abstract For Abstract see ChemInform Abstract in Full Text. [source] Enantioselective Synthesis of (S)-,-Arylpropionic Acids via Pd-Catalyzed Kinetic Resolution of Benzylic Alcohols.CHEMINFORM, Issue 28 2005Vinay V. Thakur Abstract For Abstract see ChemInform Abstract in Full Text. [source] Highly Efficient Catalytic Aerobic Oxidations of Benzylic Alcohols in Water.CHEMINFORM, Issue 23 2005Renhua Liu Abstract For Abstract see ChemInform Abstract in Full Text. [source] Silica Chloride (SiO2,Cl), a New Heterogeneous Reagent, for the Selective and Efficient Conversion of Benzylic Alcohols to Their Corresponding Chlorides and Iodides.CHEMINFORM, Issue 6 2004Habib Firouzabadi No abstract is available for this article. [source] ChemInform Abstract: Selective Iodination of Benzylic Alcohols with KI/H2SO4 Supported on Natural Kaolinitic Clay under Microwave Irradiation.CHEMINFORM, Issue 25 2002Babasaheb P. Bandgar 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: Highly Selective Oxidation of Primary and Secondary Benzylic Alcohols by KMnO4/ZrOCl2×8H2O in Diethyl Ether.CHEMINFORM, Issue 15 2002Habib Firouzabadi 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: Nitrous Oxide Oxidation of Secondary and Benzylic Alcohols Using Ruthenium Complex Catalyst.CHEMINFORM, Issue 6 2002Kentaro Hashimoto 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: Chemoselective Oxidation of Benzylic Alcohols with Solid Supported CrO3/TBHP under Microwave Irradiation.CHEMINFORM, Issue 3 2001Jasvinder Singh 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] Ionic liquid-H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPOCHINESE JOURNAL OF CHEMISTRY, Issue 3 2009Ruijun HU Abstract In ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6])-H2O, a highly chemoselective oxidation of benzylic alcohols in the presence of aliphatic ones to the corresponding hydroxyl benzyl aldehydes and ketones was allowed in high yields using N -chlorosuccinimide (NCS)/NaBr/IL-TEMPO (ionic liquid immobilized 2,2,6,6-tetramethylpiperidine-1-oxyl) as a facile and effective catalytic oxidation system. The medium, [bmim][PF6], together with the catalyst IL-TEMPO could be easily recycled for ten runs without any influence on the efficacy of the reaction in terms of yield and selectivity of the product. [source] Green, Palladium-Catalyzed Synthesis of Benzylic H -Phosphinates from Hypophosphorous Acid and Benzylic AlcoholsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2008Laėtitia Coudray Abstract Benzylic alcohols cross-couple directly with concentrated H3PO2 by using Pd/xantphos (1 or 2 mol-%). Depending on the substrate, DMF at 110 °C or t -AmOH at reflux with a Dean,Stark trap can be used. A broad range of benzylic alcohols react successfully to give moderate to good yields of the products. The preparation of other organophosphorus compounds (phosphinic and phosphonic acids) is also demonstrated. Asymmetric reaction with (R)-1-(2-naphthyl)ethanol provids the corresponding H -phosphinic acid in 77,% ee. The methodology provides a green, PCl3 -free route to benzylic- H -phosphinic acids.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] The Ritter Reaction under Truly Catalytic Brųnsted Acid ConditionsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 28 2007Roberto Sanz Abstract Simple organic acids like 2,4-dinitrobenzenesulfonic acid (DNBSA) catalyze the Ritter reaction of secondary benzylic alcohols giving rise to the corresponding N -benzylacetamides in usually high yields. Reactions can be conducted without exclusion of oxygen and without the need of dry solvents. With tertiary ,,,-dimethylbenzylic alcohols a different pathway involving a formal dimerization reaction takes place under the acid-catalytic conditions used. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Substitution- and Elimination-Free Phosphorylation of Functionalized Alcohols Catalyzed by Oxidomolybdenum TetrachlorideADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010Cheng-Yuan Liu Abstract Among 14 oxidometallic species examined for catalytic phosphorylation of the tested alcohols, oxidomolybdenum tetrachloride (MoOCl4) was found to be the most efficient with a negligible background reaction mediated by triethylamine (Et3N). The new catalytic protocol can be applied to the chemoselective phosphorylations of primary, secondary and tertiary alcohols as well as the substitution-free phosphorylations of allylic, propargylic, and benzylic alcohols. Functionalized alcohols bearing acetonide, tetrahydropyranyl ether, tert -butyldimethylsilyl ether, or ester group are also amenable to the new catalytic protocol. The most difficult scenarios involve substitution-free phosphorylations of 1-phenylethanol and 1-(2-naphthyl)ethanol which can be effected in 95 and 90% yields, respectively. ESI-MS, IR, 1H, and 31P,NMR spectroscopic analyses of the reaction progress suggest the intermediacy of an alkoxyoxidomolybdenum trichloride-triethylamine adduct such as [(RO)Mo(O)Cl3 -Et3N] to be responsible for the catalytic turnover. [source] Aerobic Oxidation of Benzylic Alcohols in Water by 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)/Copper(II) 2- N -Arylpyrrolecarbaldimino ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Abstract Novel copper(II) 2- N -arylpyrrolecarbaldimine-based catalysts for the aerobic oxidation of benzylic alcohols mediated by the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical are reported. The catalytic activity for both synthesized and in situ made complexes in alkaline water solutions was studied revealing high efficiency and selectivity (according to GC selectivity always >99%) for both of these catalytic systems. For example, quantitative conversion of benzyl alcohol to benzaldehyde can be achieved with the in situ prepared bis[2- N -(4-fluorophenyl)-pyrrolylcarbaldimide]copper(II) catalysts in 2,h with atmospheric pressure of O2 at 80,°C. Interestingly, these catalysts can utilize dioxygen as well as air or hydrogen peroxide as the end oxidants, producing water as the only by-product. [source] Enantioselective Benzylic Hydroxylation with Pseudomonas monteilii TA-5: A Simple Method for the Syntheses of (R)-Benzylic Alcohols Containing Reactive Functional GroupsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Yongzheng Chen Abstract Highly enantioselective benzylic hydroxylations of benzene derivatives (1,4) containing reactive functional groups were achieved for the first time with Pseudomonas monteilii TA-5 as biocatalyst, giving the corresponding (R)-benzylic alcohols 5,8 in 93,99% ee as the only products. Preparative biotransformations were demonstrated by the biohydroxylation of 1 and 2 with resting cells of P. monteilii TA-5 to afford (R)- 5 in 94% ee and 66% yield and (R)- 6 in 94% ee and 56% yield, respectively. The highly enantioselective biohydroxylations represent a simple access to (R)-benzylic alcohols containing reactive functional groups that are useful pharmaceutical intermediates and versatile chiral building blocks. [source] TEMPO and Carboxylic Acid Functionalized Imidazolium Salts/Sodium Nitrite: An Efficient, Reusable, Transition Metal-Free Catalytic System for Aerobic Oxidation of AlcoholsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Cheng-Xia Miao Abstract An effective catalytic system comprising a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) functionalized imidazolium salt ([Imim-TEMPO]+,X,), a carboxylic acid substituted imidazolium salt ([Imim-COOH]+,X,), and sodium nitrite (NaNO2) was developed for the aerobic oxidation of aliphatic, allylic, heterocyclic and benzylic alcohols to the respective carbonyl compounds with excellent selectivity up to >99%, even at ambient conditions. Notably, the catalyst system could preferentially oxidize a primary alcohol to the aldehyde rather than a secondary alcohol to the ketone. Moreover, the reaction rate is greatly enhanced when a proper amount of water is present. And a high turnover number (TON 5000) is achieved in the present transition metal-free aerobic catalytic system. Additionally, the functionalized imidazolium salts are successfully reused at least four times. This process thus represents a greener pathway for the aerobic oxidation of alcohols into carbonyl compounds by using the present task-specific ionic liquids in place of the toxic and volatile additive, such as hydrogen bromide, bromine, or hydrogen chloride (HBr, Br2 or HCl), which is commonly required for the transition metal-free aerobic oxidation of alcohols. [source] Trace Water-Promoted Oxidation of Benzylic Alcohols with Molecular Oxygen Catalyzed by Vanadyl Sulfate and Sodium Nitrite under Mild ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2009Zhongtian Du Abstract An inexpensive catalytic system consisting of vanadyl sulfate and sodium nitrite was developed for the oxidation of benzylic alcohols with molecular oxygen under mild conditions. Benzyl alcohols with various substitutions were efficiently converted to their corresponding aldehydes with high conversion and selectivity under 80,°C (e.g., 4-nitrobenzyl alcohol was smoothly oxidized to 4-nitrobenzyl aldehyde with 94% yield under 0.5,MPa of molecular oxygen). Halogen, noble metals, extra base or complicated ligands were avoided. Addition of a trace of water to this system before the reaction was crucial for the high efficiency. [source] ChemInform Abstract: Highly Efficient Dynamic Kinetic Resolution of Secondary Aromatic Alcohols with Low-Cost and Easily Available Acid Resins as Racemization Catalysts.CHEMINFORM, Issue 32 2010Yongmei Cheng Abstract A combination of Novozym435 with an acidic polystyrene resin CD8604 affords a new and efficient dynamic kinetic resolution of acetophenones to give the corresponding benzylic alcohols with good to excellent enantioselectivities. [source] | ||||||||||||||||||||||