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Conversion of an allylic ether to its corresponding acetal - Patent 4743401 Conversion of an allylic ether to its corresponding acetal In this process an allylic ether is contacted with an organic hydroxy compound and a catalytically effective amount of a cobalt compound which results in the formation of the corresponding acetal. A preferred class of allylic ethers, possessed of carboxylate functionality, that is reacted to form an acetal in accordance with the present invention are alkyl n-alkoxy-(n-2)-alkenoate compounds. www.freepatentsonline.com /4743401.html   (2832 words)

Vinyl acetate/allylic amine copolymer emulsions for paint having wet adhesion properties - Patent 4260533 Wet adhesion in the latex, which is required in most paint applications, is obtained by the interpolymerization of an amine having allylic functionality directly attached to the amino nitrogen atom and at least one hydrogen atom attached directly to the amino nitrogen atom. One of the advantages of the allylic amines, and the reason for their use in higher proportions than conventional wet adhesion monomers, is that a fraction of the amines can be cross-linked or reacted with various amine reactive compounds to provide unique properties in the polymer without significantly affecting the wet adhesion characteristics. The polymerization of the allylic amine proceeds by conventional free radical polymerization with the exception that the allylic amines should be converted to the salt form when polymerizing in an aqueous system. www.freepatentsonline.com /4260533.html   (2850 words)

Process for synthesizing tackifier resin page This invention is based upon the unexpected discovery that the reactivity of the most important monomers commonly used in synthesizing tackifier resins with aluminum halide catalysts can be enhanced by conducting the polymerization in the presence of an allylic halide. For instance, the conversions of 2-methyl-2-butene, cis-piperylene, and cyclopentene that are attained in polymerizations that are catalyzed with aluminum halide catalysts are increased by conducting the polymerization in the presence of an allylic halide, such as allyl chloride. Этот вымысел основан на непредвиденном открытии реактивность самых важных мономеров общ используемых в синтезировать более tackifier смолаы с алюминиевыми галоидными катализаторами может быть увеличена путем дирижировать полимерность in the presence of allylic галоид. www.patentalert.com /docs/001/z00150739.shtml   (173 words)

Allyl - Encyclopedia, History, Geography and Biography C=CH-CH Compounds containing the allyl group are often referred to as being allylic. A group, such as -OH, attached at an allylic site is sometimes described as allylic. Allylic methylene groups show special reactivity such as demonstrated in allylic oxidations, ene reactions and the Trost asymmetric allylic alkylation. www.arikah.com /encyclopedia/Allyl   (183 words)

VLU: Radical Additions and Substitutions with Alkenes - Radical Bromination in Allylic Position - ChemgaPedia Therefore, the conditions of this reaction are ideal for a bromination in allylic position. allylic bromination resembles the halogenation of alkanes - it is a two-step In the first chain propagation reaction, a bromine radical abstracts an allylic hydrogen atom from cyclohexene, yielding hydrogen bromide and an allylic cyclohexenyl radical. www.chemgapedia.de /vsengine/vlu/vsc/en/ch/12/oc/vlu_organik/radikale/radi_subst_add_alkane_alkene.vlu/Page/vsc/en/ch/12/oc/radikale/radi_brom_allyl/radi_brom_allyl.vscml.html   (473 words)

Chiral Allylic and Allenic Stannanes as Reagents for Asymmetric Synthesis Chiral Allylic and Allenic Stannanes as Reagents for Asymmetric Synthesis -alkoxy allylic stannane 26.1, a 1:1 mixture of diastereoisomers at the allylic stereocenter, underwent BF -promoted reaction with the enantioenriched aldehyde 26.2 to yield the syn adduct 26.3 as a single isomer along with recovered and enantioenriched alkoxy stannane (R)-26.1. Thus, the ee of the stereogenic allylic center in the adduct is equal to that of the starting stannane. pubs.acs.org /cgi-bin/abstract.cgi/chreay/1996/96/i01/abs/cr950037f.html   (6003 words)

ARKAT USA, Inc. The preparation of a sulfur-substituted allylic acetal is described and its application in 4+3 cycloaddition reactions with furan and cyclopentadiene is reported. Allylic acetals were first used by Murray and Albizati as progenitors of such allylic cations for the (4+3) cycloaddition reaction. In conclusion, we have developed a protocol for the generation of an allylic cation stabilized by both sulfur and oxygen atoms that is capable of undergoing a (4+3) cycloaddition reaction. www.arkat-usa.org /home.aspx?VIEW=MANUSCRIPT&MSID=506   (1683 words)

Prof. Ronald Magid Allylic compounds (CH -X and derivatives) have been of synthetic, mechanistic, and biochemical importance for more than fifty years. These projects entail the syntheses of optically active, deuterium-labeled allylic compounds and the analyses of product mixtures using chromatography, nmr spectroscopy, and polarimetry. Nucleophilic and organometallic displacement reactions of allylic compounds: stereo- and regiochemistry. www.chem.utk.edu /rmagid.html   (289 words)

ALKYL HALIDES Allylic hydrogens are hydrogens, such as the methyl hydrogens of propene, which are attached to a carbon atom which, in turn, is attached to a carbon-carbon double bond(see illustration below). Allylic hydrogens are especially easily halogenated by a free radical chain mechanism because their C-H bond dissociation energyies are relatively low, i.e., these bonds are weak and easy to break homolytically. The strong resonance stabilization of the allyl radical is the reason that the D for the allylic hydrogens of propene and other allylic hydrogens is much smaller than for typical hydrogens attached to carbon. research.cm.utexas.edu /nbauld/teach/halides.html   (2474 words)

Beilstein Journal of Organic Chemistry | Full text | A superior P-H phosphonite: Asymmetric allylic substitutions with ... In Pd-catalyzed allylic substitutions of diphenylallyl acetate, fenchyl diphenylphosphinites (FENOPs) with phenyl or anisyl groups favor the S-enantiomer, but with a 2-pyridyl unit the R-enantiomer was preferred (Scheme 3). Allylic alkylation of 1-phenyl-2-propenyl acetate by sodium dimethylmalonate (BSA-method) with Pd-FENOP- or Pd-BIFOP- catalysts. Computational transition structure analyses of allylic substitutions with ammonia mimicking the malonate nucleophile help to understand origins of enantioselectivities,[30-33] as we have shown recently for Pd-FENOP catalysts with the diphenyl allyl substrate [25]. bjoc.beilstein-journals.org /content/2/1/7   (1490 words)

Name of File Allylic Free radicals like the carbocation are conjugated with the C-1, C-2, and C-3 carbons sp2 hybridized in the free radical structure. This allows the unpaired electron that resulted from the homolytic cleavage and the Pi electrons to be delocalized along that three atom allylic system The C-4 carbon is not part of this delocalization because it is an sp3 carbon and as such has no "p" orbital to contribute to the pipeline. In fact allylic free radicals are more stable than the tertiary free radicals just as with the carbocations basically due to resonance stabilization. members.aol.com /profchm/conj.html   (2380 words)

Sn2 in the solvolysis reactions of allylic and benzylic halides. Resonance stabilization of the allylic radical, as shown in Figure 6, is not possible for the propyl radical. The red bar labeled 2 indicates the stabilization of the transition state for the formation of the allylic radical relative to the propyl radical. www.usm.maine.edu /~newton/Chy251_253/Lectures/DelocalizedBonding/DelocalizationSurvey.html   (1934 words)

Information on Allylic Sulfides and online access to Allylic Sulfides The allylic sulfides in these plants are released when the plants are cut or smashed. As a group, allylic sulfides appear to possess antimutagenic and anticarcinogenic properties as well as immune and cardiovascular protection. Specific allylic sulfides block the activity of toxins produced by bacteria and viruses. www.alternative-medicine-info.com /alternative-medicine/Allylic-Sulfides/Allylic-Sulfides.html   (421 words)

Allylic Substitutions with Acyclic Substrates   (Site not responding. Last check: 2007-10-26) For the case of the unsubstituted allylic system it was found that the Pd-C bond trans to P, not trans to N, is opened to give the sigma-complex displayed in Scheme 14. The dominating interaction is the one with the equatorial aryl group at P. Minimization of this interaction is the reason for preference of the exo over the endo diastereomer. In Scheme 18 substrates are ordered - the isopropyl case is taken from a paper of the Pfaltz[10] - according to their "broadness" and it is quite remarkable how closely the ee values parallel the steric extension. www.ch.ic.ac.uk /ectoc/papers/02/acycl.html   (1182 words)

Allylic Sulfides   (Site not responding. Last check: 2007-10-26) The allylic sulfides in these plants are released when the plants are cut or smashed. As a group, allylic sulfides appear to possess antimutagenic and anticarcinogenic properties as well as immune and cardiovascular protection. Specific allylic sulfides block the activity of toxins produced by bacteria and viruses. www.abernathyclinic.com /AllylicSulfides.htm   (125 words)

e-Prints Soton - Palladium-catalysed nucleophilic release of allylic amines from a phenolic resin e-Prints Soton - Palladium-catalysed nucleophilic release of allylic amines from a phenolic resin Palladium-catalysed nucleophilic release of allylic amines from a phenolic resin 2 circle Allylic alcohols were coupled to phenolic polystyrene resin under Mitsunobu conditions to provide substituted allyl ethers. eprints.soton.ac.uk /19477   (117 words)

M. Christian White The extraordinarily high selectivities observed for our allylic oxidation systems have enabled us to begin to test their potential for improving the efficiency of oxygenated small molecule synthesis. Further studies are targeted toward determining the role of vinyl sulfoxide in promoting allylic C-H cleavage, exploring nitrogen and carbon nucleophiles as functionalization reagents, and developing asymmetric versions of this reaction. Based on these results, it is reasonable to think that mechanistic studies of these highly selective allylic oxidation systems will continue to provide valuable new principles of catalyst design and chemical reactivity. www.scs.uiuc.edu /chem/white2.html?print=1   (786 words)

[No title] Understand the molecular orbital representation of the allylic radical and the accompanying rationale for its relative stability. Understand the molecular orbital representation of the allylic cation and the accompanying rationale for its relative stability. Place allylic and benzylic halides in this scheme of relative reactivity (vs. ordinary 1o, 2o, and 3o halides) and be able to rationalize their generally enhanced reactivity under conditions favoring either SN1 or SN2 mechanisms. www.chem.plu.edu /organic/334ss_97.htm   (10802 words)

Copper-catalyzed enantioselective allylic alkylation with alkylmetals. Synthesis of tertiary and quaternary all-carbon ... Chapter 1: Catalytic asymmetric allylic alkylation reactions with alkylmetal reagents. Allylic alkylations represent a powerful class of C-C bond forming reactions. Chapter 2: Development of asymmetric Cu-catalyzed allylic alkylation reactions of cinnamyl phosphates with dialkylzinc reagents and modular amino acid based ligands. escholarship.bc.edu /dissertations/AAI3173675   (314 words)

Allylic alcohol synthesis by addition A highly enantioselective and catalytic vinylation of aldehydes leads to allylic alcohols that are then transformed to the allylic amines via Overman's [3,3]-sigmatropic rearrangement of imidates. The scope and utility of this method are demonstrated by the synthesis of challenging allylic amines and their subsequent transformation to valuable nonproteinogenic amino acids, including both D and L configured (1-adamantyl)glycine. An easy access to (Z)-trisubstituted allylic alcohols is based on E to Z isomerization of 1-bromo-1-dialkylvinylboranes upon reaction with dialkylzinc reagents. www.organic-chemistry.org /synthesis/C1C/alcohols/allylicalcohols.shtm   (784 words)

Ab1Chapt12 A delocalized allylic radical intermediate is formed - the resonance structures of this intermediate Identify all the allylic hydrogens of the molecule. Abstract the allylic hydrogens to form allylic radicals, then draw all their resonance structures. chem.stthomas.edu /pages/Ippoliti/Ab1Chapt12.html   (129 words)

Sharpless epoxidation The structure below is not the outcome of their calculations; it is a hand-made reconstruction ('3D drawing') of the complex they suggest as a transition state that explains the experimental findings. The reagents in this reaction are: the catalysts titanium tetraisopropoxide, and enantiomerically pure diethyl tartarate (DET, either RR or SS), tert-butyl hydroperoxide (TBHP) as the oxygen source, and of course the allylic alcohol to be epoxidated. It is proposed that these reagents form an asymmetric complex, in which the allylic alcohol exposes one side of its double bond towards the oxygen to be transferred. wetche.cmbi.ru.nl /organic/sharpless   (379 words)

Chater 7-Brown-new Allylic Halogenation-The carbon adjacent to the C=C in an alkene is called an allylic carbon, and any attached H’s are called allylic hydrogens. The allylic free radical is the most stable of those discussed in Chapter 7 Allylic bromination is accomplished by using high temperatures for bromination or a special reagent called NBS (N-bromosuccinimide in CCl www.olemiss.edu /courses/chem221/CH.%207-Notes/Chater%207-Brown-new.html   (338 words)

[No title]   (Site not responding. Last check: 2007-10-26) Allylic Spin-Spin Coupling in Systems with Defined Geometry %J Australian Journal of Chemistry %D 1963/12/01 %V 16 %N 6 %P 1030-1041 %R doi:10.1071/CH9631030 %U http://www.publish.csiro.au/paper/CH9631030 %X The preparation of some 6-substituted A4-3-oxosteroids is described. As previously announced, the stereochemistry at the 6-position, which is of importance in connection with biological activity, may be deduced from examination of the N.M.R. signal due to the vinylic proton at C The general dependence of the allylic coupling constants on stereochemistry is examined and an empirical angular relation shown to exist, with the coupling constant at a maximum when the angle subtended between the allylic and vinylic protons is 90° and at a minimum when it is 0 or 180°. www.publish.csiro.au /view/journals/dsp_journal_retrieve_citation.cfm?ct=CH9631030.enw   (161 words)

SYNTHESIS OF SUBSTITUTED INDENE COMPOUNDS Functionalized indenes, such as 2-methyl-4-phenylindene, are prepared from substituted phenols (E=O), anilines (E=NH), or allylic halides (or pseudohalides) in a simple, high yield process entailing four primary steps as shown in Scheme 1. The four steps are: (1) Formation of an allylic ether or amine through alkylation of a phenol or aniline (illustrated) or by coupling of an aryl halide with an allylic alcohol or amine (not illustrated). 1) Formation of an allylic ether or amine through alkylation of a phenol or aniline (illustrated) or by coupling of an aryl halide with an allylic alcohol or amine (not illustrated). www.priorartdatabase.com /IPCOM/000030316   (364 words)

spilling We are attempting to expand the chemistry of allylic hydroxy phosphonamides and phosphonates formed in the chemistry discussed above. Allylic hydroxy phosphonates are similar to regular allylic alcohols and should undergo similar chemistry. Our initial work focused on the palladium catalyzed addition of amines to the carbonate derivatives of allylic hydroxy phosphonates, and several examples of this reaction have been performed. www.umsl.edu /chemistry/faculty/spilling.html   (832 words)

Chemistry of polyfunction The reason for substation at the allylic hydrogen atom is the low bond dissociation energies of an allylic carbon hydrogen bond. Allylic > 3º > 2º  > 1º > vinyl The allyl compound break either hemolytic producing free radical or heterolytic producing cation or anion all these product resonate which Reflect the stability of allylic radical and explain its high reactivity and possibility of formation of two product. www.kaau.edu.sa /KBADAHDAH/lecture232one.htm   (246 words)

Theses from Stockholm University: 1031 - Asymmetric Synthesis and Mechanistic Studies on Copper(I)-Catalyzed ... The thiolates were examined as ligands in the enantioselective copper(I)-catalyzed ?-substitution of allylic acetates. It was observed that the degree of chirality transfer is strongly dependent on the reaction temperature. Norinder, Jakob ; Yoshikai, Naohiko ; Bäckvall, Jan-Erling ; Nakamura, Eiichi: Unusual Homocoupling in the Reaction of Diorganocuprates with an Allylic Halide. www.diva-portal.org /su/theses/abstract.xsql?dbid=1031   (458 words)

Ch 10: Allylic systems Note that in the two resonance forms of the allylic cation, the positive charge is located on the terminal carbon atoms and never on the middle carbon. Due to the stability of these allylic cations, they are readily formed as intermediates during chemical reactions, for example S Due to the stability of these allylic radicals, they are readily formed as intermediates during chemical reactions, for example allylic halogenation. www.chem.ucalgary.ca /courses/351/Carey5th/Ch10/ch10-2.html   (272 words)

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