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Alkenes
Kinds of Alkenes Terms modified by Alkenes Selected AbstractsImine Additions of Internal Alkynes for the Synthesis of Trisubstituted (E)-Alkene and Cyclopropane Peptide IsosteresADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-13 2005Peter Wipf Abstract Divergent multi-component reactions (DMCR) involving CC bond formations can provide large increases in structural diversity and allow the rapid assembly of complex products from readily available starting materials. Cascade hydrozirconation-Zr/Zn transmetalation-imine addition of alkynes represents a versatile methodology for the synthesis of (E)-alkene and cyclopropane dipeptide isosteres. Appropriate substitutions at the sp2 -carbon of (E)-alkene peptide isosteres allow a range of Pd-catalyzed cross-coupling reactions, which can be used for the fine-tuning of the conformational and electronic properties of the parent peptide bond mimic. CC bond formation by microwave-accelerated Stille coupling of stannylalkenes represents a fast, convergent synthetic approach toward trisubstituted (E)-alkene dipeptide isosteres. [source] Wacker-Type Oxidation of Internal Olefins Using a PdCl2/N,N -Dimethylacetamide Catalyst System under Copper-Free Reaction Conditions,ANGEWANDTE CHEMIE, Issue 7 2010Takato Mitsudome Dr. Innere Werte: Ein einfaches Katalysatorsystem bestehend aus PdCl2 und N,N -Dimethylacetamid (DMA) als Lösungsmittel vermittelt die Wacker-Oxidation interner Alkene. Dabei werden keine Kupferverbindungen benötigt, und es lassen sich vielfältige Substrate mit internen Doppelbindungen umsetzen. [source] ChemInform Abstract: A Regioselective Ru-Catalyzed Alkene,Alkyne Coupling to Form (Z,Z)-1,3-Dienes.CHEMINFORM, Issue 30 2009Barry M. Trost 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: Palladium-Catalyzed Oxidative Amination of Alkenes: Improved Catalyst Reoxidation Enables the Use of Alkene as the Limiting Reagent.CHEMINFORM, Issue 13 2008Michelle M. Rogers 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] Rhodium-Catalyzed Intermolecular Chelation Controlled Alkene and Alkyne Hydroacylation: Synthetic Scope of ,-S-Substituted Aldehyde Substrates.CHEMINFORM, Issue 47 2006Michael C. Willis 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] Esterification of Alkene with Cerium(IV) Sulfate in Carboxylic Acid.CHEMINFORM, Issue 2 2004C. Akira Horiuchi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Alkene and Alkyne Oxidative Cleavage Catalyzed by RuO4 in Environmentally Acceptable Solvents.CHEMINFORM, Issue 52 2003William P. Griffith Abstract For Abstract see ChemInform Abstract in Full Text. [source] Extended Scope of Dirhodium(II)-Catalyzed Enantioselective Intramolecular 1,3-Dipolar Cycloadditions of Carbonyl Ylides with Alkene and Alkyne Dipolarophiles.CHEMINFORM, Issue 15 2003David M. Hodgson Abstract For Abstract see ChemInform Abstract in Full Text. [source] Catalytic One-Pot Synthesis of N-Phenyl Alkyl Amides from Alkene and Aniline in the Presence of Cobalt on Charcoal under Carbon Monoxide.CHEMINFORM, Issue 40 2002Sang Ick Lee Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Regioselectivity and endo/exo Selectivity in the Cycloadditions of the Phthalazinium Dicyanomethanide 1,3-Dipole with Unsymmetrical Alkene and Alkyne Dipolarophiles.CHEMINFORM, Issue 43 2001DFT Theoretical Study., Unexpected Reversals of Regiochemistry: A Combined Experimental 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] A New Long-Chain Alkene and Antituberculosis Constituents from the Leaves of Pourthiaea lucidaCHEMISTRY & BIODIVERSITY, Issue 3 2010Jih-Jung Chen Abstract A new long-chain alkene, dotriacont-1-ene (1), was isolated from the leaves of Pourthiaea lucida, together with twelve known compounds. The structure of this new compound was determined by NMR and mass-spectrometric analyses. Among the isolated compounds, , -tocospiro A (2), , -tocopheryl quinone (4), and (E)-phytol (5) exhibited antituberculosis activities (MICs ,30,,g/ml) against Mycobacterium tuberculosis H37Rv in vitro. [source] Synthesis, Crystal Structure, and Catalytic Properties of Novel Dioxidomolybdenum(VI) Complexes with Tridentate Schiff Base Ligands in the Biomimetic and Highly Selective Oxygenation of Alkenes and SulfidesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2010Abdolreza Rezaeifard Abstract Four novel dioxidomolybdenum(VI) complexes [MoO2(Lx)(CH3OH)] have been synthesized, using 2[(E)-(2-hydroxy-2-phenylethylimino)methyl]phenol derivatives as tridentate ONO donor Schiff base ligands (H2Lx) and MoO2(acac)2. A monoclinic space group was determined by X-ray crystallography from single-crystal data of a sample of these new complexes. The epoxidation of alkenes by using tert -butyl hydroperoxide and oxidation of sulfides to sulfoxides by urea hydrogen peroxide were efficiently enhanced with excellent selectivity under the catalytic influence these new MoVI complexes. The high efficiency and relative stability of the catalysts have been observed by turnover numbers and UV/Vis investigations. The electron-poor and bulky ligands promoted the effectiveness of the catalysts. [source] Solvent Effects on Catalytic Epoxidation of Alkenes by Tetra- n -butylammonium Periodate and (Tetraarylporphyrinato)manganese(III)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 20 2008Daryoush Mohajer Abstract The epoxidation of cyclooctene and cis -stilbene was performed by tetra- n -butylammonium periodate (nBu4NIO4)in the presence of (tetraarylporphyrinato)manganese(III) [Mn(por)] and imidazole (im) in various CH2Cl2/alcohol solvents (alcohol = CH3OH, C2H5OH, n -C3H7OH, i -C3H7OH, t -C4H9OH). In accord with the coordinating abilities of the alcohols to [Mn(por)], the epoxidation yields increased from CH2Cl2/CH3OH to CH2Cl2/t -C4H9OH. In the epoxidation of cis -stilbene in the presence of (acetato)(tetraphenylporphyrinato)manganese(III) [Mn(tpp)(OAc)], the cis - to trans -stilbene oxide ratio increased consistently with the bulk of the alcohol in CH2Cl2/alcohol solvents. Also, it was found that the interaction of [Mn(tpp)(OAc)] and (acetato)(tetramesitylporphyrinato)manganese(III) [Mn(tmp)(OAc)] with nBu4NIO4 in the presence of imidazole but in the absence of alkenes yields [Mn(tpp)(O)(im)]+ and [Mn(tmp)(O)(im)]+ complexes. The formation of the Mn=O species for the small linear alcohols was faster than that for the larger ones, whereas the stability of the Mn=O complex was greater in the presence of the bulkier alcohols. Attempts were made to explain these effects.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Neutral Group-IV Metal Catalysts for the Intramolecular Hydroamination of AlkenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2008Carsten Müller Abstract A detailed comparison of the group-IV metal catalysts Ti(NMe2)4, Ind2TiMe2, Ind2ZrMe2 and Ind2HfMe2 in the intramolecular hydroamination of amino alkenes is presented. Among these catalysts, the benchmark catalyst Ti(NMe2)4 is the most active in the formation of pyrrolidines. A comparison between Ind2TiMe2, Ind2ZrMe2 and Ind2HfMe2 suggests that in the synthesis of pyrrolidines, Zr complexes show the highest catalytic activity of the group-IV metal catalysts. Although Ind2TiMe2 - and the Ind2ZrMe2 -catalyzed formation of a pyrrolidine is first-order in the concentration of the substrate, the corresponding Ti(NMe2)4 -catalyzed cyclization is second-order in the concentration of the substrate. The results obtained for the formation of piperidines catalyzed by Ti(NMe2)4, Ind2TiMe2, Ind2ZrMe2 and Ind2HfMe2 suggest that for these reactions, Ti catalysts show increased catalytic activity compared with the corresponding Zr catalysts. Unfortunately, the formation of aminocyclopentane side-products by C,H activation processes is a severe drawback of the Ti catalysts. The corresponding side-products are not formed in Ind2ZrMe2 - and Ind2HfMe2 -catalyzed reactions. However, the former catalyst gives better yields of the desired piperidine products. In contrast to the results obtained for the synthesis of pyrrolidines, the formation of a piperidine is zero-order in the concentration of the substrate for the indenyl catalysts Ind2TiMe2 and Ind2ZrMe2, and first-order for the homoleptic catalyst Ti(NMe2)4. Interestingly, Ind2TiMe2 is able to catalyze a slow hydroamination of an N -methylated amino alkene, whereas the homoleptic complex Ti(NMe2)4 as well as Ind2ZrMe2 and Ind2HfMe2 do not catalyze the same reaction. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Stereoselective Synthesis of 2-Deoxyglycosides from Sulfanyl Alkenes by Consecutive "One Pot" Cyclization and Glycosylation ReactionsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2007Miguel A. Rodríguez Abstract 2-Deoxy-2-iodopyranosides 3, and 9,12 were synthesized from sulfanyl alkenes using a "one pot" consecutive cyclization,glycosylation process. Compared with the stepwise procedure, the "one pot" process gave significantly improved yields with similar or slightly lower selectivities. The "onepot" procedure was applied to the synthesis of 2,6-dideoxy-2-iodoglycoside 22, which was successfully deiodinated to afford the 2,6-dideoxyglycoside 23. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Novel Chiral (Salen)MnIII Complexes Containing a Calix[4]arene Unit as Catalysts for Enantioselective Epoxidation Reactions of (Z)-Aryl AlkenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2005Maria E. Amato Abstract New asymmetric (salen)MnIII and UO2 complexes containing a calix[4]arene unit in the ligand framework were synthesized. The UO2 complexes were characterized by 1H-, 13C-, 2D TOCSY and T-ROESY NMR spectroscopy. Furthermore, the structure of one UO2 complex was determined by single-crystal X-ray analysis. The data showed that UO2 complexes, which can be considered in first approximation models of the Mn=O oxidant active species, possess a chiral pocket and adopt relevant conformations for the selectivity of the oxygen transfer process. Epoxidation data of model alkenes with the MnIII complexes showed moderate ee values and were not conclusive in indicating that the calix[4]arene unit might be able to influence the selectivity by a molecular recognition mechanism. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Synthesis and Rearrangement of N -Organyloxy ,-Lactams Derived from a (4+2)/(3+2) Sequential Cycloaddition Reaction Involving Enol Ethers and Nitro AlkenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 21 2004Leon W. A. van Berkom Abstract The synthesis of N -organyloxy ,-lactams 2 by treatment of nitroso acetals 1 with a base is discussed. Based on the formation of a by-product, a mechanism for the rearrangement to N -organyloxy ,-lactams is proposed. This mechanism is supported by trapping of the intermediate acyl nitro compound 8 with dimethylamine. Furthermore, it was discovered that upon more forcing basic conditions these N -organyloxy ,-lactams can rearrange further to 3-organyloxy ,-lactams. By using a series of structurally diverse N -organyloxy ,-lactams the generality of this novel rearrangement is demonstrated. A mechanism for the conversion of N -organyloxy ,-lactams to 3-organyloxy ,-lactams is proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis of Polysubstituted Alkenes by Heck Vinylation or Suzuki Cross-Coupling Reactions in the Presence of a Tetraphosphane,Palladium CatalystEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2003Florian Berthiol Abstract Through the use of [PdCl(C3H5)]2/cis,cis,cis -1,2,3,4-tetrakis[(diphenylphosphanyl)methyl]cyclopentane as a catalyst, a range of vinyl bromides undergo Suzuki cross-couplings with arylboronic acids in good yields. Furthermore, the catalyst can be used at low loadings, even for reactions of sterically hindered substrates. Mediated by this catalyst, stilbene and 1,1-diphenylethylene undergo Heck reactions with aryl halides to give triarylethylene derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Cycloadditions of Bifunctional Vinyl Ethers with Electrophilic Alkenes through Tetramethylene Zwitterion IntermediatesHELVETICA CHIMICA ACTA, Issue 6 2005Bifunctional vinyl ethers react with electron-poor alkenes to cyclobutanes in good yields. The second CC bond reacted with neither the cyclobutane nor its zwitterion intermediate, even on heating. Cyclobutanes formed from ,tetracyanoethylene' (8) were transformed into tetrahydropyridines by reaction of the corresponding zwitterion with MeCN as the solvent. In contrast, cyclobutanes formed from dimethyl (dicyanomethylidene)propanedioate (9) did not react with MeCN, which is ascribed to diminished stabilization of the zwitterion intermediate, and increased steric effects. These results extend the classical studies of Huisgen and his co-workers. [source] Arylethyne Bromoboration,Negishi Coupling Route to E - or Z -Aryl-Substituted Trisubstituted Alkenes of ,98% Isomeric Purity.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2010New Horizon in the Highly Selective Synthesis of Trisubstituted Alkenes Abstract The hitherto unprecedented palladium-catalyzed cross-coupling of (Z)-,-bromo-,-arylethenylboranes can be made to proceed satisfactorily through (1) the use of highly catalytically active bis(tri- tert -butylphosphine)palladium or dichloro[N,N -bis-(2,6-diisopropylphenyl)imidazol-2-yl](m -chloropyridine)palladium and (2) conversion of the dibromoboryl group to the (pinacol)boryl group. Thus, a wide variety of carbon groups can be used to substitute bromine in ,98% stereo- and regioselectivity, while suppressing the otherwise dominant ,-debromoboration. Together with the alkylethyne-based protocols, the alkyne bromoboration,Negishi coupling tandem process has emerged as the most widely applicable and highly selective route to trisubstituted alkenes including those that are otherwise difficult to access. [source] The Substrate Spectra of Pentaerythritol Tetranitrate Reductase, Morphinone Reductase, N -Ethylmaleimide Reductase and Estrogen-Binding Protein in the Asymmetric Bioreduction of Activated AlkenesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Nicole Abstract Four flavoproteins from the old yellow enzyme (OYE) family, pentaerythritol tetranitrate (PETNR) reductase, N -ethylmaleimide reductase (NEMR), morphinone reductase (MorR) and estrogen-binding protein (EBP1), exhibited a broad substrate tolerance by accepting conjugated enals, enones, imides, dicarboxylic acids and esters, as well as a nitroalkene and therefore can be employed for the asymmetric bioreduction of carbon-carbon double (CC) bonds. In particular, morphinone reductase and estrogen-binding protein often showed a complementary stereochemical preference in comparison to that of previously investigated OYEs. [source] A Highly Diastereoselective Tertiary Amine-Catalyzed Cascade Michael,Michael,Henry Reaction between Nitromethane, Activated Alkenes and ,,,-Unsaturated Carbonyl CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010Bo Zhang Abstract A new tertiary amine-catalyzed cascade Michael,Michael,Henry reaction between nitromethane, a doubly activated alkene and an ,,,-unsaturated carbonyl compound is described, which provides a convenient and efficient synthesis for densely functionalized cyclohexanes and some bicyclic compounds in moderate to excellent yields with high diastereoselectivity. [source] Trapping of Active Methylene Intermediates with Alkenes, Indoles or Thiols: Towards Highly Selective Multicomponent ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Yanlong Gu Abstract In this paper, a basic method to access new multicomponent reactions (MCRs) is reported. The mechanism of these MCRs is based on the trapping of methylene intermediates, formed in situ by reaction of formaldehyde with electron-rich carbons, with alkene, thiol or indole derivatives. According to our strategy, a wide range of valuable skeletons has been obtained in a one-pot reaction, thus allowing a minimization of waste, cost and labor. The presented methodology exhibits a broad substrate scope and electron-rich carbons in the ,-position of a hydroxy or carbonyl group were found to be particularly efficient. More generally, this work offers new tools for creating molecular complexity and diversity from one of the simplest organic building blocks, formaldehyde. [source] Asymmetric Reduction of Activated Alkenes by Pentaerythritol Tetranitrate Reductase: Specificity and Control of Stereochemical Outcome by Reaction OptimisationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Anna Fryszkowska Abstract We show that pentaerythritol tetranitrate reductase (PETNR), a member of the ,ene' reductase old yellow enzyme family, catalyses the asymmetric reduction of a variety of industrially relevant activated ,,,-unsaturated alkenes including enones, enals, maleimides and nitroalkenes. We have rationalised the broad substrate specificity and stereochemical outcome of these reductions by reference to molecular models of enzyme-substrate complexes based on the crystal complex of the PETNR with 2-cyclohexenone 4a. The optical purity of products is variable (49,99% ee), depending on the substrate type and nature of substituents. Generally, high enantioselectivity was observed for reaction products with stereogenic centres at C, (>99% ee). However, for the substrates existing in two isomeric forms (e.g., citral 11a or nitroalkenes 18,19a), an enantiodivergent course of the reduction of E/Z -forms may lead to lower enantiopurities of the products. We also demonstrate that the poor optical purity obtained for products with stereogenic centres at C, is due to non-enzymatic racemisation. In reactions with ketoisophorone 3a we show that product racemisation is prevented through reaction optimisation, specifically by shortening reaction time and through control of solution pH. We suggest this as a general strategy for improved recovery of optically pure products with other biocatalytic conversions where there is potential for product racemisation. [source] Palladium-Catalyzed Oxidation of Phenyl-Substituted Alkenes using Molecular Oxygen as the Sole OxidantADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Aline Abstract The palladium-catalyzed aerobic oxidation of styrene and 2-vinylnaphthalene in dimethylacetamide/water or dimethylformamide/water solutions under mild conditions has been developed, in which palladium(II) chloride is used in the absence of co-catalysts or special stabilizing ligands as the sole and recyclable catalyst. The corresponding methyl ketones have been obtained in good to excellent yields with low catalyst loadings (0.2,5,mol%) and high turnover numbers (up to ca. 1000 to palladium). This simple and efficient catalytic method represents an ecologically benign and economically attractive synthetic pathway to industrially important compounds used in the manufacture of various polymers and drugs. [source] Palladium-Catalyzed Three-Component 1:2:1 Coupling of Aryl Iodides, Alkynes, and Alkenes to Produce 1,3,5-Hexatriene DerivativesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Hakaru Horiguchi Abstract The intermolecular three-component coupling of aryl iodides, diarylacetylenes, and alkenes effectively proceeds in the presence of palladium acetylacetonate and silver acetate as catalyst and base, respectively, to give the corresponding 1:2:1 coupling products, 1,3,5-hexatriene derivatives. A further homologation of the oligoene chain of the three-component coupling products by a simple procedure is also presented. [source] Highly Enantioselective Biphasic Iminium-Catalyzed Epoxidation of Alkenes.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2009On the Importance of the Counterion, of N(sp2)C(sp3) Rotamers Abstract Diastereomeric biaryliminium cations made of an (Ra)-5,5,,6,6,,7,7,,8,8,-octahydrobinaphthyl core and exocyclic appendages derived from (S)- or (R)-3,3-dimethylbutan-2-amine are effective asymmetric epoxidation catalysts for unfunctionalized alkenes. Herein, we report that the negative counterion of the iminium salts has to be chosen wisely. While the hexafluoroantimonate anion [SbF6,] is optimal for reliable results, one has to be careful about other anions and tetraphenylborate [BPh4,] in particular. We also detail that the so far unexplained "lack" of stereochemical control from the chiral exocyclic appendage in this type of catalysts is due to the existence of atropisomers around the N(sp2)C(sp3) bond that links the azepinium core to the exocyclic stereocenter. Finally, we develop a general model to predict with certainty the high selectivity in the formation of non-racemic epoxides of defined absolute configuration. [source] Palladium-Catalyzed Intermolecular Three-Component Coupling of Organic Halides with Alkynes and Alkenes: Efficient Synthesis of Oligoene CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2007Kana Shibata Abstract The intermolecular three-component coupling of aryl or vinyl halides, diarylacetylenes, and monosubstituted alkenes effectively proceeds in the presence of palladium acetate, lithium chloride, and sodium bicarbonate as catalyst, promoter, and base, respectively, in aqueous DMF or DMSO to produce the corresponding 1,3-butadiene or 1,3,5-hexatriene derivatives. Use of dienyl bromides allows the coupling to afford 1,3,5,7-octatetraenes. Under the present catalytic conditions, fulvene derivatives are also formed efficiently by the 1:2 coupling of vinyl bromides and diarylacetylenes without adding the alkenes. [source] Zirconium-Catalyzed Asymmetric Carboalumination of Alkenes: ZACA,Lipase-Catalyzed Acetylation SynergyADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4-5 2007Zhihong Huang Abstract ZACA,lipase-catalyzed acetylation tandem reactions provide highly efficient and selective routes to either (R)- or (S)-2-methyl-1-alkanols, making, for the first time, the ZACA-based asymmetric synthesis of 2-methyl-1-alkanols widely applicable and satisfactory. [source] Recent Advances in the Syntheses and Applications of Molybdenum and Tungsten Alkylidene and Alkylidyne Catalysts for the Metathesis of Alkenes and AlkynesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2007Richard Abstract The last several years have produced some key advances in the area of alkene and alkyne metathesis by high oxidation state alkylidene and alkylidyne complexes along with new applications in organic and polymer chemistry. In this review we cover some of these developments and applications. The first part of this review concerns developments in catalyst synthesis and new catalysts. The second part concerns notable applications in organic and polymer chemistry. We discuss only high oxidation state alkylidene and alkylidyne chemistry of relevance to alkene or alkyne metathesis reactions and favor studies in the homogeneous phase. [source] | ||||||||||||||||||||||||||||