Enyne Metathesis (Enyne Bond Reorganization)
... Some late transition metal salts trigger enyne bond reorganization. The pioneering work in this area came from Trost’s lab.31-36 Trost employed various Pd(II) and Pt(II) metallacyles to trigger the bond reorganization. Interest in the metal-catalyzed enyne bond reorganization, particularly in the pl ...
... Some late transition metal salts trigger enyne bond reorganization. The pioneering work in this area came from Trost’s lab.31-36 Trost employed various Pd(II) and Pt(II) metallacyles to trigger the bond reorganization. Interest in the metal-catalyzed enyne bond reorganization, particularly in the pl ...
The Organometallic Chemistry Of Transition Metals
... Organometallic compounds, with their metal–carbon bonds (e.g., WMe6 ), lie at the interface between classical organic and inorganic chemistry in dealing with the interaction between inorganic metal species and organic molecules. In the related metal–organic compound area, in contrast, the organic fr ...
... Organometallic compounds, with their metal–carbon bonds (e.g., WMe6 ), lie at the interface between classical organic and inorganic chemistry in dealing with the interaction between inorganic metal species and organic molecules. In the related metal–organic compound area, in contrast, the organic fr ...
Preparation and structural characterization of group 1 metal
... the phenolato oxygen atoms. Compound bis-(3,5-di-tertbutyl-2-hydroxyphenyl)phenylphosphine (H2[OPO]) is a suitable ligand precursor available from the literature [30]. To begin with, we report in this contribution the preparation and structural characterization of [OPO]2 with respect to group 1 meta ...
... the phenolato oxygen atoms. Compound bis-(3,5-di-tertbutyl-2-hydroxyphenyl)phenylphosphine (H2[OPO]) is a suitable ligand precursor available from the literature [30]. To begin with, we report in this contribution the preparation and structural characterization of [OPO]2 with respect to group 1 meta ...
Synthetically Important AlkaliMetal Utility Amides: Lithium, Sodium
... Schlosser KOtBu/LinBu superbase.[18] Prepared in a similar manner by adding DA(H) to a superbasic suspension of the Lochmann–Schlosser reagent in hexane, or by adding nBuLi to DA(H)/KOtBu, this was found to be superior than either LDA or KHMDS for the deprotonation of weakly acidic compounds. Sauer ...
... Schlosser KOtBu/LinBu superbase.[18] Prepared in a similar manner by adding DA(H) to a superbasic suspension of the Lochmann–Schlosser reagent in hexane, or by adding nBuLi to DA(H)/KOtBu, this was found to be superior than either LDA or KHMDS for the deprotonation of weakly acidic compounds. Sauer ...
Structurally simple
... mineral), which were determined to include methane, nitrogen and CO2 as guest molecules using mass spectrometry. 30 , 31 Later Hirotsu et al. reported the crystal structure of a macrocyclic heterocyclophane with CO2 incorporated into its hydrophobic core. 32 These were the first structurally charact ...
... mineral), which were determined to include methane, nitrogen and CO2 as guest molecules using mass spectrometry. 30 , 31 Later Hirotsu et al. reported the crystal structure of a macrocyclic heterocyclophane with CO2 incorporated into its hydrophobic core. 32 These were the first structurally charact ...
Study of η6 - cyclic π-perimeter hydrocarbon ruthenium complexes
... Abstract. Chelating mono- and di-pyridyl functionalized β-diketones, viz. 1-phenyl-3-(2-pyridyl) propane1,3-dione (pppdH) and 1,3-di(2-pyridyl)propane-1,3-dione (dppdH) ligands yielded new water soluble η6 arene ruthenium(II) complexes of the formulation [(η6 -arene)Ru(κ2 -N-O-pppdH)Cl]+ (arene = C6 ...
... Abstract. Chelating mono- and di-pyridyl functionalized β-diketones, viz. 1-phenyl-3-(2-pyridyl) propane1,3-dione (pppdH) and 1,3-di(2-pyridyl)propane-1,3-dione (dppdH) ligands yielded new water soluble η6 arene ruthenium(II) complexes of the formulation [(η6 -arene)Ru(κ2 -N-O-pppdH)Cl]+ (arene = C6 ...
Ruthenium Olefin Metathesis Catalysts: Tuning of the Ligand Environment Ruthenium olefine
... The basic subject of interest throughout this thesis is the olefin metathesis transformation. The formation of carbon-carbon double bonds is one of the most fundamental chemical processes. In this context, metathesis makes a significant contribution, since this transition metal catalyzed reaction is ...
... The basic subject of interest throughout this thesis is the olefin metathesis transformation. The formation of carbon-carbon double bonds is one of the most fundamental chemical processes. In this context, metathesis makes a significant contribution, since this transition metal catalyzed reaction is ...
Substituent groups in aryl- and arylalkylphosphanes: effects on
... The most common ligand in organometallic chemistry is carbon monoxide, which may bond to a single metal or serve as a bridge between two or three metals. A variety of other ligands have been used, including diatomic ligands (nitrogen, nitrosyl), ligands containing linear or cyclic π-electron-systems ...
... The most common ligand in organometallic chemistry is carbon monoxide, which may bond to a single metal or serve as a bridge between two or three metals. A variety of other ligands have been used, including diatomic ligands (nitrogen, nitrosyl), ligands containing linear or cyclic π-electron-systems ...
Small Reactive Sulfur-Nitrogen Compounds and Their Transition
... Mass spectral studies33on the pyrolytic decomposition of S4N4also indicate that the (red) radical SN is generated via the (colorless) heterocycle S2N2and slowly polymerizes to the (lustrous golden) chain-polymer polythiazyl, (SN),, which consists of alternating sulfur and nitrogen atoms. Although fr ...
... Mass spectral studies33on the pyrolytic decomposition of S4N4also indicate that the (red) radical SN is generated via the (colorless) heterocycle S2N2and slowly polymerizes to the (lustrous golden) chain-polymer polythiazyl, (SN),, which consists of alternating sulfur and nitrogen atoms. Although fr ...
Ylide Ligands - DIGITAL.CSIC, el repositorio institucional
... that the reaction bewteen a carbene and the corresponding nucleophile (R3P, R3N, R2S, etc) gives cleanly the expected ylide (method d) [2,3,4,9]. The carbene is usually stabilized as a diazo derivative. This method is specially representative in the case of sulfur ylides, and allows to consider the ...
... that the reaction bewteen a carbene and the corresponding nucleophile (R3P, R3N, R2S, etc) gives cleanly the expected ylide (method d) [2,3,4,9]. The carbene is usually stabilized as a diazo derivative. This method is specially representative in the case of sulfur ylides, and allows to consider the ...
Full-Text PDF
... bearing the efforts in characterizing the decomposition reactions [15]. However, olefin metathesis has successfully achieved the goal of organic synthesis that consists of reactions that drive to the formation of carbon-carbon bonds [16–18], and provides a route to unsaturated molecules. Basically, ...
... bearing the efforts in characterizing the decomposition reactions [15]. However, olefin metathesis has successfully achieved the goal of organic synthesis that consists of reactions that drive to the formation of carbon-carbon bonds [16–18], and provides a route to unsaturated molecules. Basically, ...
- Maynooth University ePrints and eTheses Archive
... Fig. 1. Structures of Apim (1) and its Schiff base derivatives, 2–6. ...
... Fig. 1. Structures of Apim (1) and its Schiff base derivatives, 2–6. ...
Full-Text PDF
... of an olefin metathesis reaction calling for a new in silico family of homogenous Ru-based catalysts bearing a phosphine–phosphonium ylide ligand, with ethylene as a substrate. Equal to conventional Ru-based catalysts bearing an N-heterocyclic carbene (NHC) ligand, the activation of these congeners ...
... of an olefin metathesis reaction calling for a new in silico family of homogenous Ru-based catalysts bearing a phosphine–phosphonium ylide ligand, with ethylene as a substrate. Equal to conventional Ru-based catalysts bearing an N-heterocyclic carbene (NHC) ligand, the activation of these congeners ...
Slide 1
... 1) No change in formal oxidation state (exception: alkylidenes) 2) The two groups that react must be cisoidal to one another 3) A vacant coordination site is generated by the migratory insertion. Therefore, a vacant site is required for the back elimination reaction (e.g., b-hydride elimination). A ...
... 1) No change in formal oxidation state (exception: alkylidenes) 2) The two groups that react must be cisoidal to one another 3) A vacant coordination site is generated by the migratory insertion. Therefore, a vacant site is required for the back elimination reaction (e.g., b-hydride elimination). A ...
"The Synthesis of Phenols and Quinones Via Fischer Carbene
... carbene complexes with alkynes is facile, occurring just above ambient temperature, and resulting in the assembly of a benzene ring from the three carbons of the α,β-unsaturated carbene complex, the two carbons of the alkyne, and the carbon of a carbon monoxide ligand (Scheme 1). The synthetic value ...
... carbene complexes with alkynes is facile, occurring just above ambient temperature, and resulting in the assembly of a benzene ring from the three carbons of the α,β-unsaturated carbene complex, the two carbons of the alkyne, and the carbon of a carbon monoxide ligand (Scheme 1). The synthetic value ...
Lecture8
... Rule 1 – Even before Odd: Nucleophilic attack occurs preferentially at even polyenes Rule 2 – Open before Closed: Nucleophilic addition occurs preferentially to open polyenes (not closed). Rule 3 - For open polyenes: - If Even: attack occurs at a terminal position. - If Odd: attack is usually NOT at ...
... Rule 1 – Even before Odd: Nucleophilic attack occurs preferentially at even polyenes Rule 2 – Open before Closed: Nucleophilic addition occurs preferentially to open polyenes (not closed). Rule 3 - For open polyenes: - If Even: attack occurs at a terminal position. - If Odd: attack is usually NOT at ...
Recent developments in the applications of palladium complexes
... Mixed NHC and phosphine palladium complexes were described and studied as catalysts in telomerization of butadiene with methanol in the presence of water (Scheme 7).59 However, neither water-soluble complexes 9 bearing sulfonated phosphines nor the complex prepared from imidazolium precursor 10 wer ...
... Mixed NHC and phosphine palladium complexes were described and studied as catalysts in telomerization of butadiene with methanol in the presence of water (Scheme 7).59 However, neither water-soluble complexes 9 bearing sulfonated phosphines nor the complex prepared from imidazolium precursor 10 wer ...
IJCA 47A(4) 560-564
... the lone electron pairs of two oxygen in ether groups. In the second case, the ligand behaves as a bidentate ligand with the lone electron pairs of azomethine nitrogen atoms. The long distance binding process can be favored for very large Cd(II), Pb(II) metal ions but not other metal ions due to hav ...
... the lone electron pairs of two oxygen in ether groups. In the second case, the ligand behaves as a bidentate ligand with the lone electron pairs of azomethine nitrogen atoms. The long distance binding process can be favored for very large Cd(II), Pb(II) metal ions but not other metal ions due to hav ...
Study of complexes of platinum group metals containing nitrogen
... the free ligands to that of the metal complexes, we find that the IR spectra of the free ligands show a sharp band at around 1672 cm1 assigned to the stretching frequencies of C]O group of the ligands, but in the case of the metal complexes the stretching frequencies of C]O group appears in the lowe ...
... the free ligands to that of the metal complexes, we find that the IR spectra of the free ligands show a sharp band at around 1672 cm1 assigned to the stretching frequencies of C]O group of the ligands, but in the case of the metal complexes the stretching frequencies of C]O group appears in the lowe ...
Metal–ligand multiple bonds as frustrated Lewis - Beilstein
... described above is one in which a coordinatively unsaturated metal acts as a Lewis base and a relatively electropositive π-acidic ligand acts as a Lewis acid. We might expect this situation to be less common since metals are typically formulated as cations and are more electropositive than the major ...
... described above is one in which a coordinatively unsaturated metal acts as a Lewis base and a relatively electropositive π-acidic ligand acts as a Lewis acid. We might expect this situation to be less common since metals are typically formulated as cations and are more electropositive than the major ...
Amphiphilic Sugar Metal Carbenes
... hydrogenation while K. B. Sharpless3 got the other half price for his work on catalysed chiral oxidation reactions. In 2005 Y. Chauvin,4 R. R. Schrock5 and R. H. Grubbs6 received the Nobel price for their work on the methatesis reaction methodology. This reaction involves a metal carbene and an olef ...
... hydrogenation while K. B. Sharpless3 got the other half price for his work on catalysed chiral oxidation reactions. In 2005 Y. Chauvin,4 R. R. Schrock5 and R. H. Grubbs6 received the Nobel price for their work on the methatesis reaction methodology. This reaction involves a metal carbene and an olef ...
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... Complexes IV and V were prepared by De Jong et af via the appropriate dibromo intermediates followed by oxidative ring closure using copper(ll) chloride. Compound VI was synthesized by converting the suitable dibromodithienyl intermediate into an unstable thiol which, without isolation, was treated ...
... Complexes IV and V were prepared by De Jong et af via the appropriate dibromo intermediates followed by oxidative ring closure using copper(ll) chloride. Compound VI was synthesized by converting the suitable dibromodithienyl intermediate into an unstable thiol which, without isolation, was treated ...
Chapter 11
... Similar to reactions with alkenes, when alkynes react with hydrohalic acid (e.g. HBr) the proton reacts with the π bond and the positively charged intermediate is reacted with the halide ...
... Similar to reactions with alkenes, when alkynes react with hydrohalic acid (e.g. HBr) the proton reacts with the π bond and the positively charged intermediate is reacted with the halide ...
Proofs to - Research Explorer
... [Fe{C(ER’x)R}L2Cp]+ [36,37]. There is a clear correlation between the extent of heteroatom stabilisation and the length of the iron to C-alpha bond; heteroatom stabilisation leads to a longer metal to carbene carbon distance as the acceptor character of the carbene ligand is reduced. The data in Tab ...
... [Fe{C(ER’x)R}L2Cp]+ [36,37]. There is a clear correlation between the extent of heteroatom stabilisation and the length of the iron to C-alpha bond; heteroatom stabilisation leads to a longer metal to carbene carbon distance as the acceptor character of the carbene ligand is reduced. The data in Tab ...
Persistent carbene
A persistent carbene (also known as stable carbene) is a type of carbene demonstrating particular stability. The best-known examples and by far largest subgroup are the N-heterocyclic carbenes (sometimes called Arduengo carbenes), for example diaminocarbenes with the general formula (R2N)2C:, where the 'R's are typically alkyl and aryl groups. The groups can be linked to give heterocyclic carbenes, such as those derived from imidazole, imidazoline, thiazole or triazole.Traditionally carbenes are viewed as so reactive that were only studied indirectly, e.g. by trapping reactions. This situation has changed dramatically with the emergence of persistent carbenes. Although they are fairly reactive substances, i.e., undergoing dimerization, many can be isolated as pure substances.Persistent carbenes can exist in the singlet or the triplet states with the singlet state carbenes being more stable. The relative stability of these compounds is only partly due to steric hindrance by bulky groups. Some singlet carbenes are thermodynamically stable in the absence of moisture and (in most cases) oxygen, and can be isolated and indefinitely stored. Others are not thermodynamically stable and will dimerise slowly over days. The less stable triplet state carbenes have half-lives measured in seconds, and therefore can be observed but not stored.