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Active Methylene Compounds (active + methylene_compound)
Selected AbstractsRuthenium Catalysts for Controlled Mono- and Bis-Allylation of Active Methylene Compounds with Aliphatic Allylic SubstratesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Hui-Jun Zhang Abstract The allylation of 1,3-dicarbonyl compounds and malononitrile with aliphatic allylic substrates is achieved under mild conditions in the presence of new ruthenium catalysts. The ruthenium complex [Ru(C5Me5)(2-quinolinecarboxylato)(CH2CHCH- n -Pr)],[BF4] as a precatalyst, allows the synthesis of mono-allylated branched derivatives. On the other hand, the parent complex [Ru(C5Me5)(MeCN)3],[PF6] as a precatalyst, straightforwardly favours the bis-allylation of the procarbonucleophiles leading to bis-allylated bis-linear products. The involvement of the two precatalysts provides a sequential synthesis of unsymmetrical mixed linear-branched bis-allylated derivatives. [source] ChemInform Abstract: Reaction of Active Methylene Compounds with 4-Dimethylaminobenzalaniline and Nematicidal Activity of the Products (III).CHEMINFORM, Issue 25 2009Amardeep Kaur 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: Reaction of Isatins with Active Methylene Compounds on Neutral Alumina: Formation of Knoevenagel Condensates and Other Interesting Products.CHEMINFORM, Issue 23 2009Manas Chakrabarty 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: Reaction of 2-Alkylthiopyridinium Salts with Active Methylene Compounds.CHEMINFORM, Issue 27 2008Masato Hoshino 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] A Simple and Efficient FeCl3 -Catalyzed Direct Alkylation of Active Methylene Compounds with Benzylic and Allylic Alcohols under Mild Conditions.CHEMINFORM, Issue 38 2007Umasish Jana 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] BF3×OEt2 -Mediated C,C Bond-Forming Reaction of ,-Hydroxyketene-(S,S)-acetals with Active Methylene Compounds and Its Application in the Synthesis of Substituted 3,4-Dihydro-2-pyridones.CHEMINFORM, Issue 19 2007Jun Liu 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] Michael Addition of Active Methylene Compounds to ,,,-Unsaturated Sulfones.CHEMINFORM, Issue 15 2006V. Padmavathi 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 Synthesis of Novel ,-Substituted ,-Butenolides by Lewis Acid Catalyzed Addition of Metal Enolates of Active Methylene Compounds to Mucohalic Acids.CHEMINFORM, Issue 49 2005Ji Zhang Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Mild, Efficient, and Green Procedure for Michael Addition of Active Methylene Compounds to Chalcones under Microwave Irradiation.CHEMINFORM, Issue 29 2005Satya Paul No abstract is available for this article. [source] Facile and one pot synthetic routes for various novel, differently fused and promising heteropolycyclesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2010Shallu Gupta Four-component one pot cyclocondensation of aromatic aldehydes 1, ethyl cyanoacetate 2, barbituric acid 3 and ammonium acetate in methanol gave substituted and functionalised pyrido[2,3-d]pyrimidine derivatives 4 and 4, after initial Knoevenagel, subsequent Micheal and final heterocyclization reactions. Compounds 4 on reaction with different active methylene compounds resulted in the formation of again functionalized and diversly substituted pyrimidonaphthyridines 5-7, 9 and benzo[b] pyrimidonaphthyridines 8. The various compounds of systems 7 and 8 on further condensation with the reactive and mostly the bifunctional moieties like urea/thiourea, and 2-aminopyridine generated the novel and differently fused dipyrimidonaphthyridines 10/11 and pyrimidonaphthyridinoquinazolines 13/14, and pyridopyrimido- pyrimido[1,8]naphthyridines 15 and pyrimidonaphthyridino- pyridoquinazolines 16, respectively, hitherto unknown in literature. Compounds 7 on condensation with o -phenylenediamine produced novel pyrimidonaphthyridinobenzodiazepines 12. Other novel systems like pyrido[2,3-d;6,5-d,]dipyrimidines 17, dipyrimido[4,5-b:5,,4,-g][1,8]naphthyridines 18, 1,3,4,6,7,8,9,11-octazabenzo[de]naphthacenes 19, dipyrimido[4,5-b:5,,4,-g][1,8]naphthyridines 20, pyrimido[5,,4,:6,7][1,8]naphthyridino[4,3-b][1,5]benzodiazepines 21, dipyrimido[4,5-b:4,,5,-f][1,8]naphthyridines 22 and dipyrimido [4,5-b:5,,4,-g][1,8] naphthyridines 23 have also been generated in this study. J. Heterocyclic Chem., (2010). [source] Synthesis and application of novel styryl dyes derived from 1,4-diethyl-1,2,3,4-tetrahydro-6-methoxyquinoxalineJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2009Vijay Satam The novel 1,4-diethyl-1,2,3,4-tetrahydro-7-methoxyquinoxalin-6-carboxaldehyde was synthesized, characterized, and condensed with suitably substituted active methylene compounds by classical Knoevenagel condensation reaction to obtain novel monostyryl dyes 8a-8e and a bis-styryl dye 8f. These novel styryl dyes have hue varying from orange to violet. The dyes were applied to polyester fibers. The spectral and thermal characteristics of the dyes and fastness properties of the dyed polyester fabric were investigated. J. Heterocyclic Chem., 46, 221 (2009). [source] Thioenols and thioamides substituted by two , -EWGs.JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 6 2008Comparison with analogous amides, enols Abstract Condensation of organic isothiocyanates with active methylene compounds gave nine thioamides RNHCSCHYY, or their isomeric thioenols RNHC(SH),=,CYY, for substrates in which Y and Y, are electron-withdrawing groups (EWG). These included derivatives of Meldrum's acid (MA) which showed 100% thioenol in all solvents. For other compounds the percentages of thioenol in CDCl3 when R,=,Ph are 100% when Y,=,CN and Y,,=,CO2Me or Y,,=,CO2CH2CCl3, 6% when Y,=,Y,,=,CO2CH2CF3, and 0% when Y,=,Y,,=,CO2Me. The chemical shift of SH (highest values 12.0,16.0,ppm) served as a probe for the thioenol structures and also for the extent of hydrogen bonding to the SH group. In contrast to simple ketones and thioketones in which thioenolization is favored over enolization by factors as large as 106, for intramolecular competition KThioenol/KEnol ratios are much lower than for systems not substituted by , -EWGs. X-ray crystallography of the 5-anilido-MA derivative shows a hydrogen-bonded thioenol structure. ,(OH), ,(NH), KEnol, and crystallographic data for analogous thioenol and enol systems are compared. Copyright © 2008 John Wiley & Sons, Ltd. [source] Organometallic dyes: Part 1.APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2001Synthesis of orange to cyan dyes based on donor, acceptor chromogenes using ferrocene as the donor group, conjugated Abstract A novel series of organometallic donor,conjugated,acceptor dyes derived from ferrocene as the donor group have been synthesized via the Knoevenagel reaction of ferrocene carboxaldehyde and various active methylene compounds to give a range of dyes ranging from orange to blue,green in color. The most bathochromic dye is that derived from dialkyl thiobarbituric acid and the least is that derived from the tetralone. The dyes showed an unusual negative solvatochromism as the solvent polarity increased. All dyes synthesized are expected to have some non-linear optical properties, as evidenced from the pronounced solvatochromism. Copyright ©,2001 John Wiley & Sons, Ltd. [source] Highly Efficient Non-Palladium-Catalyzed Controlled Synthesis and X-ray Analysis of Functionalized 1,2-Diaryl-, 1,2,3-Triaryl-, and 1,2,3,4-Tetraarylbenzenes,CHEMISTRY - AN ASIAN JOURNAL, Issue 2 2007Atul Goel Dr. Abstract A general, two-step, highly efficient synthesis of 1,2-diaryl-, 1,2,3-triaryl-, and 1,2,3,4-tetraarylbenzenes from simple stitching of ,-oxo-ketene- S,S -acetals and active methylene compounds via a lactone intermediate is described. This procedure offers easy access to highly functionalized arylated benzenes that contain sterically demanding groups in good to excellent yields. The novelty of the procedure lies in the construction of aromatic compounds with the desired conformational flexibility along the molecular axis in a transition-metal-free environment through easily accessible precursors. Crystal analysis of these arylated benzene scaffolds showed that the peripheral aryl rings are arranged in a propeller-like fashion with respect to the central benzene ring. Examination of the crystal packing in the structure of a 1,2,3,4-tetraarylbenzene revealed an N,,,, interaction between molecules related by a two-fold screw axis running in the direction of the a axis. Interestingly, the repeating array of N,,,, interactions around the axis of this 1,2,3,4-tetraarylbenzene forces the molecules into a helical pattern. [source] Direct Substitution of the Hydroxy Group at the Allylic/propargylic Position with Carbon- and Heteroatom- centered Nucleophiles Catalyzed by Yb(OTf)3CHINESE JOURNAL OF CHEMISTRY, Issue 4 2008Wen HUANG Abstract An efficient and highly selective Yb(OTf)3 -catalyzed direct substitution of the hydroxy group at the allylic and propargylic positions with a variety of heteroatom- and carbon-centered nucleophiles, such as alcohols, thiols, amines, amides and active methylene compounds has been developed. The advantages of the present catalytic system are wide availability of the starting materials, especially for tolerance to thiols, no need for dried solvents and additives, mild conditions, short time of reaction, simple manipulation and environmentally friendly catalyst that can be recovered and reused at least ten times without significant reduction of activity. [source] | ||||||||||||||||||||||