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Carbonyl
Kinds of Carbonyl Terms modified by Carbonyl Selected AbstractsChemInform Abstract: anti-Diastereo- and Enantioselective Carbonyl (Hydroxymethyl)allylation from the Alcohol or Aldehyde Oxidation Level: Allyl Carbonates as Allylmetal Surrogates.CHEMINFORM, Issue 32 2010Yong Jian Zhang Abstract The first enantioselective carbonyl (hydroxymethyl)allylation in the presence of aromatic, allylic, or aliphatic alcohols (II) is reported employing an (S)-SEGPHOS-modified iridium C,O-benzoate complex to provide products (III) in good isolated yields, good anti-diastereoselectivities and high enantioselectivities. [source] ChemInform Abstract: Catalytic Nucleophilic Addition Reaction to (2-Furyl)carbene Intermediates Generated from Carbonyl,Ene,Ynes.CHEMINFORM, Issue 3 2009Koji Miki 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: Lewis Base Catalyzed 1,3-Dithiane Addition to Carbonyl and Imino Compounds Using 2-Trimethylsilyl-1,3-dithiane.CHEMINFORM, Issue 2 2009Makoto Michida 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] Theoretical Investigations of Uranyl,Ligand Bonding: Four- and Five-Coordinate Uranyl Cyanide, Isocyanide, Carbonyl, and Hydroxide ComplexesCHEMINFORM, Issue 24 2005Jason L. Sonnenberg Abstract For Abstract see ChemInform Abstract in Full Text. [source] Sn-, Zeolite as Diastereoselective Water-Resistant Heterogeneous Lewis Acid Catalyst for Carbon,Carbon Bond Formation in the Intramolecular Carbonyl,Ene Reaction.CHEMINFORM, Issue 29 2004Avelino Corma Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Convenient One-Pot Procedure to Afford Bicyclic Molecules by Stereospecific Iron Carbonyl Mediated [6 + 2] Ene-Type Cyclization: A Possible Approach to Gelsemine.CHEMINFORM, Issue 12 2004Anthony J. Pearson Abstract For Abstract see ChemInform Abstract in Full Text. [source] Unprecedented 1,3-Dipolar Cycloaddition of Azomethine Ylides to Ester Carbonyl.CHEMINFORM, Issue 47 2002Mikhail S. Novikov Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A Highly Diastereoselective Synthesis of Homoallylic Alcohol/Amine Appended Uracils: The Role of the Uracil C-4 Carbonyl in Diastereoselectivity Control.CHEMINFORM, Issue 41 2001Subodh Kumar 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 Control of Hydrogenation Among Aromatic Carbonyl and Benzyl Alcohol Derivatives Using Pd/C(en) Catalyst.CHEMINFORM, Issue 37 2001Kazuyuki Hattori 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: Carbonyl and Olefin Reactivities for the Baylis,Hillman Reaction of Fluorocarbonyls.CHEMINFORM, Issue 33 2001P. Veeraraghavan Ramachandran 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] Comparison of Isoelectronic Heterometallic and Homometallic Binuclear Cyclopentadienylmetal Carbonyls: The Iron,Nickel vs. the Dicobalt SystemsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2008Jun D. Zhang Abstract The heterometallic binuclear cyclopentadienylironnickel carbonyl compounds Cp2FeNi(CO)n (n = 3, 2, 1; Cp = ,5 -C5H5) have been studied by density functional theory (BP86) for comparison with the isoelectronic homometallic dicobalt derivatives Cp2Co2(CO)n. The FeNi tricarbonyl is shown to be the doubly bridged isomer Cp2Fe(CO)Ni(,-CO)2 with an Fe,Ni distance of 2.455 Å (BP86), in accord with experiment and in contrast to Cp2Co2(CO)3 where singly and triply bridged but not doubly bridged isomers are found. The dicarbonyl compounds Cp2FeNi(,-CO)2 and Cp2Co2(,-CO)2 both have analogous doubly bridged structures with M=M distances around 2.35 Å, suggesting formal M=M double bonds. The monocarbonyl compounds have analogous singly bridged axial structures Cp2FeNi(,-CO) and Cp2Co2(,-CO) with metal,metal distances in the range 2.05 Å (M2 = Co2) to 2.12 Å (M2 = FeNi) consistent with the formal M,M triple bonds required for the favored 18-electron configuration. Open-shell states of Cp2FeNi(,-CO) are found to have even lower energies than the closed-shell structure, which indicates that the ground state of Cp2FeNi(,-CO) might be a high spin structure. However, the global minimum for the monocarbonyl is found to be a singlet "hot dog" perpendicular Cp2NiFe(CO) structure with a terminal CO group bonded to the iron atom. Other higher energy perpendicular structures are also found for Cp2FeNi(CO)n (n = 3, 2, 1) with terminal CO groups and bridging Cp rings. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Volatile composition of the laksa plant (Polygonum hydropiper L.), a potential source of green note aroma compoundsFLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2005J. Jiang Abstract Volatile compounds were extracted from laksa plant (Polygonum hydropiper L.) by three isolation techniques,dynamic headspace sampling, simultaneous distillation and extraction (SDE) and liquid,liquid extraction with dichloromethane (DCM). In the GC,MS analysis of the volatile extracts, a total of 46 compounds were identi,ed, including 14 carbonyls, 14 alcohols, 10 hydrocarbons, four esters, two furans, one acid and one base. Carbonyls (aldehydes/ketones) and alcohols are the predominant classes of volatile compounds, accounting for almost 90% (or above) of the total volatiles extracted from the plant. The major compounds include dodecanal (3,40%), (E)-2-hexenal (20,35%), decanal (4,22%), (Z)-3-hexen-1-ol (4,31%), hexanal (1.7,5.1%) and , -caryophyllene (1.7,2.3%). Signi,cantly high levels of both (E)-2-hexenal (leaf aldehyde) and (Z)-3-hexen-1-ol (leaf alcohol) may make the weed plant become a potential source of green note aroma componds. More (Z)-3-hexen-1-ol was found in the stem while more (E)-2-hexenal was detected in the leaf. The laksa stem appeared to contain more decanal and dodecanal but less esters than the leaf. Different isolation techniques produced volatile extracts with different proportions of the major volatile components. Copyright © 2005 John Wiley & Sons, Ltd. [source] Preventing cell death induced by carbonyl stress, oxidative stress or mitochondrial toxins with vitamin B anti-AGE agentsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 3 2008Rhea Mehta Abstract Carbonyls generated by autoxidation of carbohydrates or lipid peroxidation have been implicated in advanced glycation end product (AGE) formation in tissues adversely affected by diabetes complications. Tissue AGE and associated pathology have been decreased by vitamin B1/B6 in trials involving diabetic animal models. To understand the molecular cytoprotective mechanisms involved, the effects of B1/B6 vitamers against cytotoxicity induced by AGE/advanced lipid end product (ALE) carbonyl precursors (glyoxal/acrolein) have been compared to cytotoxicity induced by oxidative stress (hydroperoxide) or mitochondrial toxins (cyanide/copper). Thiamin was found to be best at preventing cell death induced by carbonyl stress and mitochondrial toxins but not oxidative stress cell death suggesting that thiamin pyrophosphate restored pyruvate and ,-ketoglutarate dehydrogenases inhibited by mitochondrial toxicity. However, B6 vitamers were most effective at preventing oxidative stress or lipid peroxidation cytotoxicity suggesting that pyridoxal or pyridoxal phosphate were antioxidants and/or Fe/Cu chelators. A therapeutic vitamin cocktail could provide maximal prevention against carbonyl stress toxicity associated with diabetic complications. [source] Efficient Construction of Oxa- and Aza-[n.2.1] Skeletons: Lewis Acid Catalyzed Intramolecular [3+2],Cycloaddition of Cyclopropane 1,1-Diesters with Carbonyls and Imines,ANGEWANDTE CHEMIE, Issue 18 2010Siyang Xing Dr. Brückenbau: Eine Lewis-Säure-vermittelte intramolekulare [3+2]-Cycloaddition zwischen Cyclopropan-1,1-diestern und Aldehyden, Ketonen oder Iminen (siehe Schema) eröffnet einen allgemeinen und effizienten Zugang zu verbrückten Oxa- und Aza[n.2.1]-Gerüsten (n=2,4). Als Anwendungsbeispiel wurde die Kernstruktur von Platensimycin aufgebaut. [source] ChemInform Abstract: Efficient Construction of Oxa- and Aza-[n.2.1] Skeletons: Lewis Acid Catalyzed Intramolecular [3 + 2] Cycloaddition of Cyclopropane 1,1-Diesters with Carbonyls and Imines.CHEMINFORM, Issue 36 2010Siyang Xing Abstract A Lewis acid promoted intramolecular [3+2] cycloaddition of cyclopropane 1,1-diesters with aldehydes, ketones, and imines is developed to provide a general and efficient strategy for construction of bridged oxa- and aza-[n.2.1] skeletons. [source] ChemInform Abstract: Efficient, Direct ,-Methylenation of Carbonyls Mediated by Diisopropylammonium Trifluoroacetate.CHEMINFORM, Issue 28 2010Alejandro Bugarin 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: ,-Halogenation of ,,,-Unsaturated Carbonyls and Dihalogenation of Alkenes Using Bisacetoxyiodobenzene/Pyridine Hydrohalides.CHEMINFORM, Issue 5 2010Marsewi Ngatimin 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: Tandem Chain Extension,Iodomethylation Reactions: Formation of ,-Functionalized ,-Keto Carbonyls.CHEMINFORM, Issue 51 2008Qinglin Pu 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] Barbier Coupling in Water: SnCl2 -Mediated and Co(acac)2 -Catalyzed Allylation of Carbonyls.CHEMINFORM, Issue 52 2005Mihir K. Chaudhuri Abstract For Abstract see ChemInform Abstract in Full Text. [source] Surfactant/I2/Water: An Efficient System for Deprotection of Oximes and Imines to Carbonyls under Neutral Conditions in Water.CHEMINFORM, Issue 31 2005Pranjal Gogoi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Sulfamic Acid as a Cost-Effective and Recyclable Catalyst for Protection of Carbonyls to Acetals and Ketals under Mild Conditions.CHEMINFORM, Issue 18 2005Weizhong Gong No abstract is available for this article. [source] Preparation of Fluoroalkyl Imines, Amines, Enamines, Ketones, ,-Amino Carbonyls, and ,-Amino Acids from Primary Enamine Phosphonates.CHEMINFORM, Issue 18 2005Francisco Palacios Abstract For Abstract see ChemInform Abstract in Full Text. [source] Selective Reduction of C=O in ,,,-Unsaturated Carbonyls Through Catalytic Hydrogen Transfer Reaction over Mixed Metal Oxides.CHEMINFORM, Issue 20 2004Sachin U. Sonavane Abstract For Abstract see ChemInform Abstract in Full Text. [source] Pinacol Formation and Reduction of Aromatic Carbonyls with Magnesium,Methanol at Ambient Temperature.CHEMINFORM, Issue 4 2004Jitender M. Khurana Abstract For Abstract see ChemInform Abstract in Full Text. [source] Solid Phase Oxidation of Alcohols and Benzyl Halides to Carbonyls Using Bromate Exchange Resin.CHEMINFORM, Issue 50 2003Atul Pd. Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: An Efficient Protection of Carbonyls and Deprotection of Acetals Using Decaborane.CHEMINFORM, Issue 30 2002Seung Hwan Lee 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: Anions of Transition Metals Carbonyls in Nucleophilic Vinyl Substitution.CHEMINFORM, Issue 51 2001Part 7. 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] Phase transition behavior and structure of the thermotropic liquid crystal 6-{[(4,-{[(undecyl)carbonyl]oxy}biphenyl-4yl)carbonyl]oxy}-1-hexyneCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2006Leijing Liu Abstract The phase transition behaviors and corresponding structures of 6-{[(4,-{[(undecyl)carbonyl]oxy}biphenyl-4yl)carbonyl]oxy}-1-hexyne (A4EE11) were investigated using differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and wide angle X-ray diffraction (WAXD). In comparison with the published homologues, 5-{[(4,-heptoxy-biphenyl-4-yl)carbonyl]oxy}-1-pentyne (A3EO7) which shows a monotropic smectic A (SmA) phase and a metastable monotropic smectic C (SmC) phase; 5-{[(4,-heptoxy-biphenyl-4-yl)oxy]carbonyl}- 1-pentyne (A3E'O7) that exhibits three enantiotropic stable liquid crystalline (LC) phases, SmA phase, SmC phase and smectic X (SmX) phase; 5-{[(4,-heptoxy-biphenyl-4-yl)carbonyl]oxy}-1-undecyne (A9EO7) which has a monotropic SmA phase and a metastable crystal phase, A4EE11 integrates the enantiotropy, monotropy and metastability of the LC phases of those three compounds. Upon cooling from isotropic state to room temperature, in the temperature range of 62.0 to 58.5°C, A4EE11 shows an enantiotropic smectic A (SmA) phase with a layer spacing d=32.69Å. Further lowering the temperature, it enters into a metastable monotropic smectic B (SmB) phase with a longer layer spacing d=34.22Å which has a tendency towards crystallization. The metastability of the liquid crystalline phase may associate to the linkage order of the ester bridge between the mesogenic core and the flexible spacer. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Application of polymeric surfactants in micellar electrokinetic chromatography-electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugsELECTROPHORESIS, Issue 5-6 2006Jingguo Hou Abstract Chiral micellar EKC (CMEKC) coupled to ESI-MS using polymeric surfactants as pseudostationary phases is investigated for simultaneous enantioseparation of two benzodiazepines, (±)-oxazepam ((±)-OXA) and (±)-lorazepam ((±)-LOR), and one benzoxazocine, (±)-nefopam ((±)-NEF). First, enantioselectivity and electrospray sensitivity of six chiral polymeric surfactants for all three chiral compounds are compared. Second, using poly(sodium N -undecenoyl- L -leucinate) as pseudostationary phase, the organic modifiers (methanol (MeOH), isopropanol, and ACN) are added into the running buffer to further improve chiral resolution (RS). Next, a CMEKC-ESI-MS method for the simultaneous enantioseparation of two benzodiazepines is further developed by using a dipeptide polymeric surfactant, poly(sodium N -undecenoxy carbonyl- L,L -leucyl-valinate) (poly- L,L -SUCLV). The CMEKC conditions including nebulizer pressure, capillary length, ammonium acetate concentration, pH, poly- L,L -SUCLV concentration, and capillary temperature were optimized to achieve maximum chiral RS and highest sensitivity of MS detection. The spray chamber parameters (drying gas temperature and drying gas flow rate) as well as sheath liquid conditions (MeOH content, pH, flow rate, and ionic strength) were found to significantly influence MS S/N of both (±)-OXA and (±)-LOR. Finally, a comparative study between simultaneous UV and MS detection showed high plate numbers, better chiral RS, and enhanced detectability with CMEKC-MS. However, speed of analysis was faster using CMEKC-UV. [source] Polymeric alkenoxy amino acid surfactants: II.,Chiral separations of ,-blockers with multiple stereogenic centersELECTROPHORESIS, Issue 6 2004Syed A. A. Rizvi Abstract Two amino acid-based (leucine and isoleucine) alkenoxy micelle polymers were employed in this study for the separation of multichiral center-bearing ,-blockers, nadolol and labetalol. These polymers include polysodium N -undecenoxy carbonyl- L -leucinate (poly- L -SUCL) and polysodium N -undecenoxy carbonyl- L -isoleucinate (poly- L -SUCIL). Detailed synthesis and characterization were reported in our previous paper [26]. It was found that poly- L -SUCIL gives better chiral separation than poly- L -SUCL for both nadolol and labetalol isomers. The use of 50,100 mM poly- L -SUCIL as a single chiral selector provided separation of four and three isomers of labetalol and nadolol, respectively. Further optimization in separation of both enantiomeric pairs of nadolol and labetalol was achieved by evaluation of type and concentration of organic solvents, capillary temperature as well type and concentration of cyclodextrins. A synergistic approach, using a combination of poly- L -SUCIL and sulfated ,-CD (S-,-CD) was evaluated and it showed dramatic separation for enantiomeric pairs of nadolol. On the other hand for labetalol enantiomers, separation was slightly decreased or remain unaffected using the dual chiral selector system. Finally, simultaneous separation of both nadolol and labetalol enantiomers was achieved in a single run using 25 mM poly- L -SUCIL and 5% w/v of S-,-CD in less then 35 min highlighting the importance of high-throughput chiral analysis. [source] | |||||||||||||||||||||||||||||||||||||||||||