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Oxidative Cyclization (oxidative + cyclization)
Selected AbstractsEfficient Stereoselective Synthesis of Nitrocyclopropanes by the Oxidative Cyclization of Michael Adducts of Nitroolefins with Activated Methylene CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2008Renhua Fan Abstract An efficient oxidative cyclopropanation of the Michael adducts of nitroolefins with activated methylene compounds by the combination of iodobenzene diacetate and tetrabutylammonium iodide is reported. Highly functionalized nitrocyclopropanes are synthesized in moderate to good yields via the Michael addition and cyclopropanation with high diastereoselectivity and enantioselectivity under mild conditions. [source] Modular Synthesis of 1,2-Diamine Derivatives by Palladium-Catalyzed Aerobic Oxidative Cyclization of Allylic Sulfamides,ANGEWANDTE CHEMIE, Issue 32 2010Richard Allylische Sulfamide gehen in Gegenwart eines Palladiumkatalysatorsystems in Tetrahydrofuran bei Raumtemperatur eine aerobe oxidative Cyclisierung ein. Die cyclischen Sulfamide lassen sich einfach mit LiAlH4 in 1,2-Diamine überführen, und Substrate, die sich von chiralen Allylaminen ableiten, cyclisieren mit sehr hoher Diastereoselektivität. TFA=Trifluoracetat. [source] ChemInform Abstract: New Modes for the Osmium-Catalyzed Oxidative Cyclization.CHEMINFORM, Issue 29 2010Timothy J. Donohoe 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: Aqueous Iodine(III)-Mediated Stereoselective Oxidative Cyclization for the Synthesis of Functionalized Fused Dihydrofuran Derivatives.CHEMINFORM, Issue 25 2010Yang Ye 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: Oxidative Cyclization of 3-Cinnamoyltropolones with I2/DMSO/H2SO4 System.CHEMINFORM, Issue 15 2010Wentao Gao 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: Synthesis of the Pyoverdin Chromophore (Va) by a Biomimetic Oxidative Cyclization.CHEMINFORM, Issue 33 2009Raymond C. F. Jones 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: Pyridinium Chlorochromate Mediated Oxidative Cyclization of Sterically Crowded ,,,-Unsaturated Alcohols.CHEMINFORM, Issue 5 2008A. Srikrishna 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] Use of Stang,s Reagent, PhI(CN)OTf, to Promote Pummerer-Like Oxidative Cyclization of 2-(Phenylthio)indoles.CHEMINFORM, Issue 40 2004Ken S. Feldman Abstract For Abstract see ChemInform Abstract in Full Text. [source] Copper(II) Acetate Promoted Oxidative Cyclization of Arylsulfonyl-o-allylanilines.CHEMINFORM, Issue 37 2004Eric S. Sherman Abstract For Abstract see ChemInform Abstract in Full Text. [source] Oxidative Cyclization of Arenecarbaldehyde 4-Methylquinolin-2-ylhydrazones to 3-Aryl-9-methyl-1,2,4-triazolo[4,3-a]quinolines Using Nitrous Acid: A Reinvestigation.CHEMINFORM, Issue 40 2003Om V. Singh Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and PET Oxidative Cyclization of Silyl Enol Ethers: Build-up of Quasi-Steroidal Carbocycles.CHEMINFORM, Issue 12 2003Jens O. Bunte Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Ruthenium-Catalyzed Oxidative Cyclization of 2-Aminobenzyl Alcohol with Ketones: Modified Friedlaender Quinoline Synthesis.CHEMINFORM, Issue 16 2002Chan Sik Cho 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: Oxidative Cyclization of Cinnamyl Ethers Mediated by CAN: A Stereoselective Synthesis of 3,4-trans Disubstituted Tetrahydrofuran Derivatives.CHEMINFORM, Issue 52 2001Vijay Nair 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: Oxidative Cyclization of cis- and trans-2,3-Dibenzylbutyrolactones Using Phenyl Iodonium Bis(trifluoroacetate) and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone.CHEMINFORM, Issue 42 2001Robert S. Ward 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: Improved RuO4 -Catalyzed Oxidative Cyclization of Geraniol-Type 1,5-Dienes to cis-2,5-Bis(hydroxymethyl)tetrahydrofuranyldiols.CHEMINFORM, Issue 40 2001Vincenzo Piccialli 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] Enantioselective Synthesis of Cyclic Ethers Through a Vanadium-Catalyzed Resolution/Oxidative Cyclization.CHEMINFORM, Issue 29 2006Aurelien Blanc 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] Ruthenium(II)-Catalyzed Cyclization of Oxabenzonorbornenes with Propargylic Alcohols: Formation of IsochromenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2006Karine Villeneuve Abstract The ruthenium-catalyzed cyclization of a propargylic alcohol with an oxabenzonorbornene in methanol leads to an unanticipated isochromene framework. The catalytic cycle to form this product is believed to go through an oxidative cyclization of the two unsaturated partners with the ruthenium catalyst, followed by ,-hydride elimination, tautomerization andhydroruthenation. The ruthenacyclobutane thus obtained further undergoes [2+2] cycloreversion to form a ruthenium,carbene intermediate that atypically rearranges via a [1,3]-alkoxide shift and finally reductively eliminates to produce the desired compound. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Mild oxidative cyclization of sydnone-benzoylhydrazone with lead oxide to 2,5-disubstituted-1,3,4-oxadiazole,sydnone hybrid derivativesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2009Kuo-Chen Chiang The mild oxidation of sydnone-benzoylhydrazone hybrids with lead oxide in acetic acid/dichloromethane solution inducted their intramolecular cyclization to provide the corresponding 2,5-disubstituted-1,3,4-oxidiazole derivatives. The sydnone moiety has been efficient preserved for the future work in the mild oxidation. J. Heterocyclic Chem., (2009). [source] Synthesis of new heterocycles containing more than one 1,2,3-thia or selenadiazole ringsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2007Mousa Al-Smadi The diketones 2a-d with different alkyl chain length are used for the synthesis of di-1,2,3-thia or selenadiazole derivatives 4a-d and 5a-d. The diketones 2a-d where prepared by a unique method through the reaction between the corresponding dibromoalkanes 1a-d and ethyl acetoacetate, which are transformed into the corresponding semicarbazone derivatives 3a-d. The di-1,2,3-thia or selenadiazole derivatives 4a-d and 5a-d were prepared from the semicarbazones derivatives 3a-d on oxidative cyclization with thionyl chloride and selenium dioxide respectively in high yield. [source] Iodobenzene diacetate on alumina: Efficient synthesis of 1,3,4-oxadiazolyl-1,8-naphthyridines in solventless system using microwavesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2006K. Mogilaiah 1-(5-Aryl-[1,3,4]oxadiazol-2-ylmethyl)-3-(p -methoxyphenyl)-1H -[1,8]naphthyridin-2-ones (5) were synthesized by the oxidative cyclization of [2-oxo-3-(p -methoxyphenyl)-2H -[1,8]naphthyridin-1-yl]acetic acid arylidene-hydrazides (4) with alumina-supported iodobenzene diacetate (IBD) in solvent-free conditions under microwave irradiation. The products are obtained in good yields and in a state of high purity. [source] Synthesis of functionalized compounds containing pyridazine and related moietiesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2005Jurij Svete 3-Aminopyridazines 17 and 3-hydrazinopyridazines 18 were used as building blocks for the preparation of various types of functionalized, pyridazine ring containing compounds. 3-Aminopyridazines were employed in the synthesis of 3-(6-chloroimidazo[1,2- b]pyridazin-2-yl)alanines 26, 27 and for the preparation of 3-amino-4H -pyrimido[1,2- b]pyridazin-4-ones 103, intermediates in the ,ring switching' synthesis of alkyl 1-pyridazin-3-yl-1,2,3-triazole-4-carboxylates 106. On the other hand, hydrazinopyridazines 18 were employed in a two-step preparation of 3-functionalized 1,2,4-triazolo[4,3- b]pyridazines via condensation with functionalized aldehydes and their enamino analogs followed by oxidative cyclization of the intermediate hydrazones. In this manner, 1,2,4-triazolo[4,3- b]pyridazin-3-yl substituted alanines 29, 30, polyols 33, 39,48, C -nucleosides 49, 50, and terpenes 58, 62, 64,69 were prepared. In another general approach, 3-hydrazinopyridazines 18 were treated with functionalized enaminones as 1,3-dielectrophiles to give the 1-(substituted pyridazin-3-yl)-1H -pyrazole derivatives containing an ester 72, 73, 75, 76, alanine 79, 84, 85, 87, 2-phenylethylamine 97, 99, and ,-amino alcohol functional element 98, 100. In the reaction of 4-oxohomoglutamate 82 with hydrazine hydrate and methyl hydrazine, chiral functionalized tetrahydropyridazinones 88a,b were obtained. [source] ChemInform Abstract: Fluorine-Containing Quinazolines Annulated at the Pyrimidine Ring.CHEMINFORM, Issue 41 2010E. V. Nosova Abstract The title compounds are synthesized by the reaction of 2- and 4-hydrazino-substituted quinazolines with aldehydes and subsequent oxidative cyclization or by alkylation of 2-alkylthio-4(3H)-quinazolinones with bromoethanol and ipso-substitution of the alkylthio group. [source] Solvent-Enhanced Diastereo- and Regioselectivity in the PdII -Catalyzed Synthesis of Six- and Eight-Membered Heterocycles via cis -AminopalladationCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2009Árpád Balázs Abstract The PdII -catalyzed intramolecular oxidative cyclization of tosyl-protected cis- and trans - N -allyl-2-aminocyclohexanecarboxamides was examined, and efficient syntheses of cyclohexane-fused pyrimidin-4-ones and 1,5-diazocin-6-ones were developed. In the course of the research, a marked solvent effect was observed on both the regio- and diastereoselectivity. Additionally, a novel PdII -mediated domino oxidation, oxidative amination reaction was discovered. Our experimental and theoretical findings suggest that the reactions proceed via a cis -aminopalladation mechanism. [source] The Biosynthesis of Vancomycin-Type Glycopeptide Antibiotics,A Model for Oxidative Side-Chain Cross-Linking by Oxygenases Coupled to the Action of Peptide SynthetasesCHEMBIOCHEM, Issue 2 2005Daniel Bischoff Dr. Model mutants. The biosynthesis of glycopeptide antibiotics must be understood before it can be reprogrammed to generate altered antibiotics. Based on a detailed HPLC-ESI-MS analysis of linear and cyclic peptide intermediates of balhimycin biosynthesis mutants, a new model for glycopeptide assembly is suggested (see figure). We propose that the three central oxidative cyclizations by P450-dependant monooxygenases occur during peptide assembly before cleavage from the nonribosomal peptide synthetase complex. [source] | ||||||||||||||||||||||