AICHE JOURNAL, Issue 6 2010
Jiping Mao
Abstract Novel microfibrous-structured silver catalysts were developed for gas-phase selective oxidation of mono-/aromatic-/di-alcohols. Sinter-locked three-dimensional microfibrous networks consisting of 5 vol % 8-,m-Ni (or 12-,m-SS-316L) fibers and 95 vol % void volume were built up by the papermaking/sintering processes. Silver was then deposited onto the surface of the sinter-locked fibers by incipient wetness impregnation method. At relatively low temperatures (e.g., 380°C), the microfibrous-structured silver catalysts provided quite higher activity/selectivity compared to the electrolytic silver. The microfibrous Ag/Ni-fiber offered much better low-temperature activity than the Ag/SS-fiber. The interaction at Ag particles and Ni-fiber interface not only visibly increased the active/selective sites of Ag+ ions and Agn,+ clusters but also significantly promoted their low-temperature reducibility and ability for O2 activation. In addition, the microfibrous structure provided a unique combination of large void volume, entirely open structure, high thermal conductivity and high permeability. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]

Allylic Amination of Internal Alkynes with Aromatic and Aliphatic Amines Using Polymer-Supported Triphenylphosphane,Palladium Complex as a Heterogeneous and Recyclable Catalyst

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 26 2010
Yogesh S. Wagh
Abstract A facile and novel protocol for the allylic amination of internal alkynes with amines by using a polymer-supported triphenylphosphane,palladium complex [PS,TPP,Pd] as a highly active heterogeneous reusable catalyst was developed. The catalyst exhibited remarkable activity and is reusable over five consecutive cycles. The protocol was applicable for a variety of hindered and functionalized aromatic/aliphatic amines and afforded the desired allylic products in good to excellent yield. [source]

Aromatic and Benzylic C,H Bond Functionalization Upon Reaction between Nitriles and Perfluoroalkyl Sulfoxides

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 31 2009
Yohan Macé
Abstract We studied the thermal behavior of some intermediates formed by reaction of nitriles with perfluoroalkyl sulfoxides upon trifluoromethanesulfonic anhydride activation. Bistriflate ketal 3, precursor of sulfilimine 1, may undergo a rearrangement to sulfanyl nitrile 5 after triflic acid elimination under thermal conditions. With p -tolyl trifluoromethyl sulfoxide, remote triflic acid elimination from intermediate 4 leads to benzamide 8 formation. These reactions involve, respectively, selective functionalization of the aromatic ortho C,H bond or the benzylic C,H bond para to the sulfoxide group. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

Introduction of Aromatic and Heteroaromatic Groups in the 2- and 8-Positions of the Tröger's Base Core by Suzuki, Stille and Negishi Cross-Coupling Reactions , A Comparative Study

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2005
Carlos Solano
Abstract A comparative study on the bis(functionalization) of the Tröger's base core by aromatic and heteroaromatic groups using palladium-catalyzed cross-coupling reactions is presented. Three different reactions, the Suzuki, Stille, and Negishi couplings, were investigated using Tröger's base analogues equally substituted in the 2,8-positions with (HO)2B, Bu3Sn and ZnCl groups, respectively, as the metallated component. Six aryl halides with different electronic and steric properties were employed as coupling partners. The presence of the bulky and electron-rich phosphane P(tBu)3 as co-catalyst was found to play an important role. In addition, the palladium source, [Pd(PPh3)4] or [Pd2(dba)3], was also found to be an important factor for the yield of the reactions. The Suzuki coupling was found to be the best method in general, giving excellent yields for most aryl halides, whereas the Stille and Negishi couplings gave moderate to good yields. Finally, the crystal structures of the 4-nitrophenyl- and the 2-pyridyl-appended analogues of Tröger's base, 7d and 7f, are presented in the Supporting Information. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Efficient Tandem Biocatalytic Process for the Kinetic Resolution of Aromatic ,-Amino Acids

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010
Bian Wu
Abstract We describe a simple and efficient enzymatic tandem reaction for the preparation of enantiomerically pure , -phenylalanine and its analogues from the corresponding racemates. In this process, phenylalanine aminomutase (PAM) catalyzes the stereoselective isomerization of (R)- , -phenylalanines to (S)- , -phenylalanines, which are in situ transformed to cinnamic acids by phenylalanine ammonia lyase (PAL). Preparative scale conversions are done with a mutated PAM with enhanced catalytic activity. [source]

Morpholinium Trifluoroacetate-Catalyzed Aldol Condensation of Acetone with both Aromatic and Aliphatic Aldehydes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7 2010
Kristina Zumbansen
Abstract We report a highly efficient, general and practical method for the aldol condensation of acetone with aromatic and aliphatic aldehydes, using morpholinium trifluoroacetate as a catalyst. [source]

Highly Efficient and Stereoselective Julia,Kocienski Protocol for the Synthesis of ,-Fluoro-,,,-unsaturated Esters and Weinreb Amides Employing 3,5-Bis(trifluoromethyl)phenyl (BTFP) Sulfones

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2008
Diego
Abstract ,-Fluoroacetates 3 and Weinreb amide 4, bearing a ,-[3,5-bis(trifluoromethyl)phenyl]sulfonyl (BTFP-sulfonyl) group at the ,-position, are employed in the highly stereoselective synthesis of ,-fluoro-,,,-unsaturated alkenoates and Weinreb amides, respectively. Aromatic and aliphatic aldehydes are condensed under extremely mild and simple reaction conditions using potassium carbonate in dimethylformamide at room temperature under solid-liquid phase-transfer catalysis conditions in good yields and high Z -diastereoselectivities, specially in the case of the fluorinated Weinreb amides. A detailed computational mechanistic study suggests a final non-concerted elimination of sulfur dioxide and 3,5-bis(trifluoromethyl)phenoxide and explains the observed high stereoselectivities for the reaction on the basis of thermodynamic and kinetic considerations. [source]

Highly Enantioselective Allylation of Aromatic ,-Keto Phosphonates Catalyzed by Chiral N,N,- Dioxide-Indium(III) Complexes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2 2008
Jinglun 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]

Aromatic,aromatic interaction of amitriptyline: Implication of overdosed drug detoxification

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2005
Dong-Won Lee
Abstract The objectives of this work are to explore the ,,, complexation of amitriptyline with , electron-deficient aromatic rings and demonstrate the feasibility of ,,, complexation for overdosed drug detoxification. Water-soluble oligochitosan was chemically modified with dinitrobenzenesulfonyl groups to induce selective binding toward amitriptyline through ,,, complexation. NMR studies showed that benzenesulfonyl and dinitrobenzenesulfonyl protons were upfield shifted by the addition of amitriptyline, indicating the formation of ,,, complexes. The ,,, complexation of amitriptyline is driven primarily by a desolvation driving force, whereas the magnitude of interaction is dictated by the complementrary electrostatic interaction. Isolated rat heart tests revealed that dinitrobenzenesulfonyl oligochitosan prevented the amitriptyline-induced cardiotoxicity and was itself not cardiotoxic. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:373,381, 2005 [source]

Lyotropic Liquid Crystalline Polyamides Containing Aromatic, Heterocyclic Structures: Preparation and Properties

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 17 2006
Pengtao Liu
Abstract Summary: A series of novel lyotropic liquid crystalline polyamides derived from 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-(aminophenoxyl)phenyl)]-phthalazinone (DHPZ-DA), p -phenylene diamine (PPD) and terephthaloyl dichloride (TPC) have been successfully synthesized by the low temperature solution polycondensation method. The copolymers obtained with inherent viscosity of ,1.21 to 3.29 dl,·,g,1, determined in NMP (1 wt.-% LiCl) or concentrated H2SO4 at 25,°C, were confirmed to be amorphous by WAXD and differential scanning calorimetry (DSC). Their solubility was improved by the introduction of non-coplanar, twisted phthalazinone moieties and ether linkages into the main chain with the result that they can be soluble in some polar solvents containing a small amount of LiCl. Their Tgs were all above 310,°C and 10% weight loss temperatures in nitrogen above 500,°C. Most of these polyamides can form an anisotropic phase in concentrated H2SO4, NMP (1 wt.-% LiCl) and DMAc (1 wt.-% LiCl) solutions, observed on a polarizing light microscope. Optical micrograph (×40) of polyamide P-4060 at 10 wt.-% in NMP/LiCl (1% w/v) solution at room temperature. [source]

Decarboxylative Cross-Coupling of Aryl Tosylates with Aromatic Carboxylate Salts,

ANGEWANDTE CHEMIE, Issue 6 2010
Lukas
Ein Kupfer/Palladium-Dimetallkatalysator ermöglicht die Verwendung von Tosylaten als Kohlenstoff-Elektrophile in decarboxylierenden Kupplungsreaktionen. Aromatische Carboxylatsalze mit vielfältigem Substitutionsmuster konnten mit diesen preiswerten und leicht erhältlichen Elektrophilen in guten Ausbeuten zu den Biarylverbindungen gekuppelt werden (siehe Schema; NMP=N -Methylpyrrolidon). [source]

ChemInform Abstract: Highly Efficient and Versatile Pd-Catalyzed Direct Alkynylation of Both Azoles and Azolines.

CHEMINFORM, Issue 34 2010
Seok Hwan Kim
Abstract Aromatic and aliphatic bromoacetylenes are applied to the reaction with a variety of the heterocyclic compounds as oxazoles, benzoxazoles, imidazoles, benzimidazoles, benzothiazoles and a fused oxazole. [source]

ChemInform Abstract: Enantioselective Friedel,Crafts Alkylation of Indoles with Aromatic ,,,-Unsaturated Aldehydes Catalyzed by Diphenylprolinol Silyl Ether.

CHEMINFORM, Issue 16 2010
Zhi-Jing Wang
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: Reactions of Methyl 4-Hetaryl-2,4-dioxobutanoates with a Mixture of Aminoazole and Aromatic (Heteroaromatic) Aldehyde.

CHEMINFORM, Issue 1 2009
V. L. Gein
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: Reactions of in situ Generated N-Boc Nitrones with Aromatic and Heteroaromatic Grignard Reagents: Application to the Synthesis of Zileuton.

CHEMINFORM, Issue 28 2008
Xavier Guinchard
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: Instability of the Al42- "All-Metal Aromatic" Ion and Its Implications.

CHEMINFORM, Issue 26 2008
Daniel S. Lambrecht
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 Hydrogenation of Aromatic, Aliphatic, and ,,,-Unsaturated Acyl Silanes Catalyzed by Tol-binap/Pica Ruthenium(II) Complexes: Practical Synthesis of Optically Active ,-Hydroxysilanes.

CHEMINFORM, Issue 26 2008
Noriyoshi Arai
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]

Evidence for d-Orbital Aromaticity in Sn- and Pb-Based Clusters: Is Sn2- 12 Aromatic?

CHEMINFORM, Issue 46 2007
De-Li Chen
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]

Condensation of Reactive Phenols with Aromatic 1,2-Diketones: A Single Step Protocol for Synthesis of Benzo-Fused ,-Lactones.

CHEMINFORM, Issue 15 2006
Sabir H. Mashraqui
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 Cu-Catalyzed Asymmetric Conjugate Addition of Alkylzinc Reagents to Aromatic and Aliphatic Acyclic Nitroalkenes.

CHEMINFORM, Issue 48 2004
Dawn M. Mampreian
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

A Convenient Method for Preparing Aromatic ,,,-Unsaturated Ketones from ,,,-Unsaturated Acyl Chlorides and Arylboronic Acids via Suzuki,Miyaura Type Coupling Reaction.

CHEMINFORM, Issue 21 2004
Yoshio Urawa
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Synthesis of Aromatic (E)- or (Z)-,,,-Unsaturated Amides with Total or Very High Selectivity from ,,,-Epoxyamides and Samarium Diiodide.

CHEMINFORM, Issue 15 2004
Jose M. Concellon
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Novel Synthesis of Sulfones from ,,,-Dibromomethyl Aromatic.

CHEMINFORM, Issue 17 2003
Feng Xu
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

ChemInform Abstract: Reactions of N-(2,2-Dichloro-2-phenylethylidene)arenesulfonamides with Aromatic and Heterocyclic Compounds.

CHEMINFORM, Issue 23 2002
G. N. Rozentsveig
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: ,-Aromatic and Sulfur Nucleophilic Partners in Cationic ,-Cyclizations: Intramolecular Amidoalkylation and Thioamidoalkylation Cyclization via ,-Carbinol Lactams.

CHEMINFORM, Issue 46 2001
Nicolas Hucher
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: An ab initio Study of the NMR Properties (Absolute Shieldings and NICS) of a Series of Significant Aromatic and Antiaromatic Compounds.

CHEMINFORM, Issue 42 2001
Ibon Alkorta
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: Catalytic, Highly Enantioselective Friedel,Crafts Reactions of Aromatic and Heteroaromatic Compounds to Trifluoropyruvate.

CHEMINFORM, Issue 27 2001
A Simple Approach for the Formation of Optically Active Aromatic, Heteroaromatic Hydroxy Trifluoromethyl Esters.
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: Magnesium in Methanol Mediated Deoxygenation of the Cyclic Thionocarbonates of Aromatic 2,3-Dihydroxy Esters.

CHEMINFORM, Issue 27 2001
Ho Sik Rho
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: Efficient Aromatic and Heteroatom Acylations Using Catalytic Indium Complexes with Lithium Perchlorate.

CHEMINFORM, Issue 19 2001
Christopher J. Chapman
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: A Catalyst for Efficient and Highly Enantioselective Hydrogenation of Aromatic, Heteroaromatic, and ,,,-Unsaturated Ketones.

CHEMINFORM, Issue 13 2001
Mark J. Burk
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]