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Insertion Reactions (insertion + reaction)
Selected AbstractsChemInform Abstract: Asymmetric Intermolecular N,H Insertion Reaction of Phenyldiazoacetates with Anilines Catalyzed by Achiral Dirhodium(II) Carboxylates and Cinchona Alkaloids.CHEMINFORM, Issue 41 2010Hiroaki Saito Abstract A novel catalytic system consisting of a rhodium salt and dihydrocinchonine is used for the synthesis of phenylglycine derivatives (III) by asymmetric N-H insertion reaction of phenyldiazoacetate (I) with anilines (II). [source] ChemInform Abstract: Spirolactone Syntheses Through a Rhodium-Catalyzed Intramolecular C,H Insertion Reaction: Model Studies Towards the Synthesis of Syringolides.CHEMINFORM, Issue 10 2010Mauricio Navarro Villalobos 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 Facile Anchoring of the Bisphosphonate Moiety into Alcohols and Phenols Through Copper Carbenoid Mediated O,H Insertion Reaction.CHEMINFORM, Issue 48 2007Delphine Lecercle 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] An Efficient Synthesis of Cyclic Urethanes from Boc-Protected Amino Acids Through a Metal Triflate-Catalyzed Intramolecular Diazocarbonyl Insertion Reaction.CHEMINFORM, Issue 7 2007Jae-Chul Jung 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] The First Example of Magnesium Carbenoid 1,3-CH Insertion Reaction: A Novel Method for Synthesis of Cyclopropanes from 1-Chloroalkyl Phenyl Sulfoxides in High Yields.CHEMINFORM, Issue 20 2005Tsuyoshi Satoh Abstract For Abstract see ChemInform Abstract in Full Text. [source] Insertion Reactions of an Aminogermylene and Formation of a Single-Source Precursor for GeTe Thin FilmsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2009Tianniu Chen Abstract Insertion reactions between a liquid germylene 1, and either a carbodiimide or dialkyl telluride lead to the formation of the group-14-metal(II) guanidinate complex 2 or the stable group-14-metal terminal alkyl tellurolate compound 3, respectively. The complexes 2 and 3 were structurally elucidated by multinuclear NMR and single-crystal X-ray crystallography. The use of 3 as a single-source precursor (SSP) for the MOCVD of GeTe films was demonstrated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Insertion Reactions of 1,2-Disubstituted Olefins with an , -Diimine Palladium(II) ComplexHELVETICA CHIMICA ACTA, Issue 8 2006Carla Carfagna Abstract The migratory insertions of cis or trans olefins CH(X)CH(Me) (X,=,Ph, Br, or Et) into the metal,acyl bond of the complex [Pd(Me)(CO)(iPr2dab)]+ [B{3,5-(CF3)2C6H3}4], (1) (iPr2dab,=,1,4-diisopropyl-1,4-diazabuta-1,3-diene,=,N,N, -(ethane-1,2-diylidene)bis[1-methylethanamine]) are described (Scheme,1). The resulting five-membered palladacycles were characterized by NMR spectroscopy and X-ray analysis. Experimental data reveal some important aspects concerning the regio- and stereochemistry of the insertion process. In particular, the presence of a Ph or Br substituent at the alkene leads to the formation of highly regiospecific products. Moreover, in all cases, the geometry of the substituents in the formed palladacycle was the same as in the starting olefin, as a consequence of a cis addition of the Pd,acyl fragment to the CC bond. Reaction with CO and MeOH of the five-membered complex derived from trans-, -methylstyrene (=,[(1E)-prop-1-enyl]benzene) insertion, yielded the 2,3-substituted , -keto ester 9 with an (2RS,3SR)-configuration (Scheme,3). [source] Versatile Reactivity of Alkynyl Fischer Carbene Complexes Toward Pentafulvenes: Carbocyclization and C,H Insertion Reactions.CHEMINFORM, Issue 34 2006Jose Barluenga 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] Synthesis of Functionalized Bicyclo[3.2.1]octan-6-ones for Diterpenoids: Allylsilane Directed Pummerer Reaction: Insertion Reactions of Diazoketones.CHEMINFORM, Issue 26 2003Philip Magnus Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Rhodium(II)-Carbenoid C,H Insertion Reactions in the Synthesis of ,,,,-Dioxospirane Systems.CHEMINFORM, Issue 34 2001Pompiliu S. Aburel 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] Divergent Insertion Reactions of Pt,Carbenes Generated from [3+2] Cyclization of Platinum-Bound PyrylliumsCHEMISTRY - A EUROPEAN JOURNAL, Issue 1 2009Chang, Ho Oh Prof. Good fusion: We describe the reactivity of Pt,carbene B, derived from enynals 1 via A, with Pt catalysts to afford fused cyclopropanes 2, which are obtained by insertion into the CH bond of the , position. Acid-catalyzed rearrangement of the cyclopropanes 2 smoothly occurred to form spiranes 3 (see scheme). [source] Insertion Reactions of an Aminogermylene and Formation of a Single-Source Precursor for GeTe Thin FilmsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2009Tianniu Chen Abstract Insertion reactions between a liquid germylene 1, and either a carbodiimide or dialkyl telluride lead to the formation of the group-14-metal(II) guanidinate complex 2 or the stable group-14-metal terminal alkyl tellurolate compound 3, respectively. The complexes 2 and 3 were structurally elucidated by multinuclear NMR and single-crystal X-ray crystallography. The use of 3 as a single-source precursor (SSP) for the MOCVD of GeTe films was demonstrated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] A Density Functional Study of the Hydrogenation of Ketones Catalysed by Neutral Rhodium-Diphosphane ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2006Francine Agbossou-Niedercorn Abstract The potential energy profile of RhI -catalysed hydrogenation of ketones has been computed for the simple model system [Rh{H3POCH2CH2N(H)PH3}(Cl)] using DFT calculations. The general sequence of the catalytic cycle involves coordination of the carbonyl derivative to the neutral RhI complex followed by oxidative addition of molecular hydrogen providing rhodium dihydride intermediates. The latter are converted into alkoxy hydrides by a migratory insertion reaction. Reductive elimination of the alcohol and substitution of the latter by the incoming substrate completes the catalyticcycle. Intermediates and transition states of all catalyticsteps have been located. Two isomeric derivatives bearingthe model substrate have been found for the [Rh{H3POCH2CH2N(H)PH3}(Cl)(H2CO)] complex. Eight diastereomeric pathways have been followed for the cis addition of molecular hydrogen to [Rh{H3POCH2CH2N(H)PH3}(Cl)(H2CO)] leading to eight distinct isomeric dihydride intermediates. Four dihydride complexes can be considered as the more accessible compounds. The site preference for migratory insertion and transition states discriminates the main path of the catalytic reaction. Migratory insertion to form the alkoxy hydride constitute the turn over limiting step of the process. The potential energy profile has been found to be smooth without excessive activation barriers. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Mechanistic studies of intramolecular CH insertion reaction of arylnitrenes: isotope effect, configurational purity and radical clock studiesJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 1 2005Shigeru Murata Abstract In order to reveal the mechanism of the intramolecular CH insertion of arylnitrenes, three experiments were carried out: measurement of isotope effects, determination of the extent of configurational retention and radical clock studies. Irradiation of the deuterium-substituted azide 4 - d in an inert solvent exclusively afforded the indolines 5 - h and 5 - d, in which the kinetic isotope effect kH/kD on the intramolecular CH insertion of the nitrene was evaluated as 12.6,14.7 at room temperature. A chiral chromatographic analysis of the indoline 11 obtained from the optically active azide (S)- 6 revealed that the enantiomeric purity of the starting azide was almost completely lost during the intramolecular CH insertion of the photolytically generated nitrene (enantiomeric excess <10%). The thermolysis of the azide 7 at 180°C mainly gave a mixture of the cyclopropyl ring-opened products 20,22, together with the intramolecular CH insertion product with an intact cyclopropyl ring 19. On the basis of these observations, we concluded that the intramolecular CH insertion of the nitrene proceeds primarily by the hydrogen abstraction,recombination mechanism. We propose, however, a small contribution of the concerted mechanism to the intramolecular CH insertion, based on the solvent dependence of the isotope effect and the extent of the configurational retention. Copyright © 2004 John Wiley & Sons, Ltd. [source] Photo-induced cross-linking mechanism in azide,novolac negative photoresists: molecular level investigation using NMR spectroscopyMAGNETIC RESONANCE IN CHEMISTRY, Issue 9 2003Debmalya Roy Abstract Negative photoresists are composed of a photoactive component (aromatic azides/bisazides) and cyclized rubber or novolac resin dissolved in an organic solvent. Hydrogen abstraction and/or insertion reaction of the reactive nitrene intermediate formed during photoirradiation of the azide result in a cross-linked network of the novolac resin. The molecular weight of novolac resin in the exposed part of the photoresist film thus increases compared with that of the unexposed part. This makes the exposed part insoluble in the alkaline developer. Exploiting this change in physical property, a pattern can be transferred to a substrate from a mask. A better understanding of the exact mechanism of cross-linking reactions is very important to the design of a high-performing negative photoresist. A quinone,imine-type complex has been proposed earlier involving the aromatic moiety of novolac resin as the reaction site. A more recent study focuses the attack of nitrene on the methylenic bridge and hydroxyl group of novolac resins, which were found to be responsible for the cross-linking reaction along with the aromatic moiety of novolac resin. However, in our study no evidence was found for the involvement of a methylenic hydrogen or aromatic moiety of novolac resin in the cross-linking reaction. The 1H NMR, 13C NMR and DEPT-135 spectra before and after photolysis indicate that the cross-linking site is predominantly the hydroxyl group of novolac resin. Multiple reaction sites of attack for the nitrene intermediate have been demonstrated in cashew nut shell liquid (CNSL)-based novolac resin by 1H NMR spectroscopy, which in turn further increases the cross-linked network in the exposed part of a negative photoresist. Copyright © 2003 John Wiley & Sons, Ltd. [source] ChemInform Abstract: Asymmetric Intermolecular N,H Insertion Reaction of Phenyldiazoacetates with Anilines Catalyzed by Achiral Dirhodium(II) Carboxylates and Cinchona Alkaloids.CHEMINFORM, Issue 41 2010Hiroaki Saito Abstract A novel catalytic system consisting of a rhodium salt and dihydrocinchonine is used for the synthesis of phenylglycine derivatives (III) by asymmetric N-H insertion reaction of phenyldiazoacetate (I) with anilines (II). [source] Highly Concise Synthesis of 3'-"Up"-ethynyl-5'-methylbicyclo- [3.1.0]hexyl Purine and Pyrimidine Nucleoside Derivatives Using Rhodium(II) Carbenoid Cycloaddition and Highly Diastereoselective Grignard ReactionCHINESE JOURNAL OF CHEMISTRY, Issue 12 2009Zunhua Yang Abstract Synthesis of north -5'-methylbicyclo[3.1.0]hexyl purine and pyrimidine nucleosides with an ethynyl group at C-3' position has been successfully accomplished by a facile method. Methylbicyclo[3.1.0]hexanone (±)- 5 having three contiguous chiral centers was remarkably simply constructed only by four steps containing a carbenoid insertion reaction in the presence of rhodium(II) acetate dimer and CuSO4, giving a correct relative stereochemistry of the generated three chiral centers. Upon Grignard reaction of (±)- 5 with ethynylmagnesium bromide, exclusive diastereoselectivity was observed. Condensation of glycosyl donor (±)- 9 with purine nucleobase afforded only the desired N9 -alkylated nucleoside, while condensation with pyrimidine, N3 -benzoylated uracil gave the desired N1 -alkylated nucleoside (±)- 13 with the undesired O2 -alkylated nucleoside (±)- 14. Probably, (±)- 14 would be formed due to steric hindrance caused upon approaching for N1 -alkylation. [source] Synthesis and Reactivity of New Bis(tetramethylpiperidino)(phosphanyl)alumanes,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 27 2007Tassilo Habereder Abstract Syntheses for the new bis(2,2,6,6-tetramethylpiperidino)(phosphanyl)alumanes, tmp2AlP(SiMe3)2, tmp2AlP(SnMe3)2 and (tmp2Al)2PPh are described along with spectroscopic characterization and X-ray crystallographic structure determinations. In addition, the insertion reactions between tmp2AlP(SiMe3)2 and CO2, COS and CS2 are described and compared with the outcomes for CO2 insertion reactions with tmp2AlCl and tmp2AlMe. In the case of the amino-phosphanyl-alumane, the Al,P bond undergoes the insertion chemistry in contrast to Al,N bond insertions observed with tmp2AlCl and tmp2AlMe. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] In situ diagnostics of the decomposition of silacyclobutane on a hot filament by vacuum ultraviolet laser ionization mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 5 2007Y. J. Shi Abstract The gas-phase reaction products of silacyclobutane (SCB) and 1, 1-dideuterio-silacyclobutane (SCB- d2) from a hot-wire chemical vapor deposition (HWCVD) chamber were diagnosed in situ using vacuum ultraviolet (VUV) laser single-photon ionization (SPI) coupled with time-of-flight (TOF) mass spectrometry. The SCB molecule was found to decompose at a filament temperature as low as 900 °C. Both Si- (silylene, methylsilylene, and silene) and C-containing (ethene and propene) species were produced from the SCB decomposition on the filament. Ethene and propene were detected by the mass spectrometer. It is demonstrated that the formation of ethene is favored over that of propene. The experimental study of hot-wire decomposition of SCB- d2 shows that propene is most likely produced by a process that is initiated by a 1,2-H(D) migration to form n -propylsilylene, followed by an equilibration with silacyclopropane, which then decomposes to propene. The detection of ethene in our experiment indicates that a competitive route of fragmentation exists for SCB decomposition on the filament. It has been shown that this competitive route occurs without H/D scrambling. The highly reactive silylene, silene, and methylsilylene species produced from SCB decomposition underwent either insertion reactions into the SiH bonds of the parent molecule or ,-type addition reaction across the double and triple CC bonds. The dimerization product of silene, 1,3-disilacyclobutane, at m/z = 88 was also observed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Synthesis and Characterization of 2-Mono- and 1,2-Diaminocarba- closo -dodecaborates M[1-R-2-H2N- closo -CB11H10] (R=H, Ph, H2N, CyHN),CHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2009Maik Finze Dr. Abstract The first primary 2-aminocarba- closo -dodecaborates [1-R-2-H2N- closo -CB11H10], (R=H (1), Ph (2)) have been synthesized by insertion reactions of (Me3Si)2NBCl2 into the trianions [7-R-7- nido -CB10H10]3,. The difunctionalized species [1,2-(H2N)2 - closo -CB11H10] (3) and 1-CyHN-2-H3N- closo -CB11H10 (H- 4) have been prepared analogously from (Me3Si)2NBCl2 and 7-H3N-7- nido -CB10H12. In addition, the preparation of [Et4N][1-H2N-2-Ph- closo -CB11H10] ([Et4N]- 5) starting from PhBCl2 and 7-H3N-7- nido -CB10H12 is described. Methylation of the [1-Ph-2-H2N- closo -CB11H10], ion (2) to produce 1-Ph-2-Me3N- closo -CB11H10 (6) is reported. The crystal structures of [Et4N]- 2, [Et4N]- 5, and 6 were determined and the geometric parameters were compared to theoretical values derived from DFT and ab initio calculations. All new compounds were studied by NMR, IR, and Raman spectroscopy, MALDI mass spectrometry, and elemental analysis. The discussion of the experimental NMR chemical shifts and of selected vibrational band positions is supported by theoretical data. The thermal properties were investigated by differential scanning calorimetry (DSC). The pKa values of 2-H3N- closo -CB11H11 (H- 1), 1-H3N- closo -CB11H10 (H- 7), and 1,2-(H3N)2 - closo -CB11H10 (H2 - 3) were determined by potentiometric titration and by NMR studies. The experimental results are compared to theoretical data (DFT and ab initio). The basicities of the aminocarba- closo -dodecaborates agree well with the spectroscopic and structural properties. [source] | ||||||||||