In this context, this review is an attempt to provide a broad but digestible overview of tetrasubstituted C–C double bond formation via olefin metathesis, with an emphasis on the recent developments achieved in this area. These developments are actually signifying the great potential for further advancement of this exhilarating research field.
Figure PR4.1. Olefin metathesis produces longer-chain "internal olefins" from shorter chain "terminal olefins". What does that reaction have to do with addition reactions involving double bonds? Clearly, the alkenes have double bonds. In addition, so do the metal oxides. Metal atoms inside the metal oxides are bridged together by oxygen atoms.
At its simplest, an olefin metathesis reaction is two olefins (alkenes) exchanging substituents on their double bonds. Olefin metathesis catalysts, such as the Grubbs catalyst now in common use, contain a carbon–metal double bond (usually to ruthenium, Ru) and have the general structure M═ CH ─ R Figure 31.3.
Zeise''s salt, KPt(C2H4)Cl3, was the first characterized organometallic compound; it was also the first olefin pi‐complex. But as it was discovered in 1827‐30 in the middle of a fight between ...
31.5 • Olefin Metathesis Polymerization Perhaps the most important advance in polymer synthesis in recent years has been the development of olefin metathesis polymerization by Yves Chauvin of the Institut Français du Pétrole, Robert H. Grubbs of CalTech, and Richard R.Schrock of MIT who shared the 2005 Nobel Prize in Chemistry for their work. At its …
Abstract The binding behavior of pillar[5]arenes (P5As) towards a series of olefin guests ((E)-1,4-dichlorobut-2-ene (1E), (Z)-1,4-dichlorobut-2-ene (1Z), (E)-but-2-ene-1,4-diol (2E), and (Z)-but-2-ene-1,4-diol (2Z), as well as an alkyne derivative 1,4-dichlorobut-2-yne (3)) have been studied in organic solution. P5As exhibit considerable selectivities for the …
By using a (-)-riboflavin photocatalyst (E T =50 kcal ⋅ mol −1) the conjugated C−C double bond of substrate (E,E)−213 was selectively isomerized towards the corresponding product with Z-geometry, while the non …
A symmetric Li|Li cell was assembled with LiPF 6 dissolved in EC/DEC as electrolyte to investigate the effect of olefin modification on battery performance. The …
Note that, like ring-opening polymerization, olefin polymerization depends on molecules reacting with other molecules that are just like them. That isn''t likely to happen; they will need something to come along and induce reaction between them. Olefin polymerization is thus another case in which monomers are tied together through a chain …
Furthermore, because we see extensive double-bond isomerization in Fig. 6 samples before much dimerization occurs for any of the C10 to C18 olefins, many carbenium ions obviously form on the catalyst''s surface and undergo proton elimination and desorption before they react with bulk olefin to form dimer. The slow step in dimer …
1 · Introduction. Since their commercialization in the 1990s, lithium-ion battery (LIB) chemistries have had a high impact on our modern life, with currently growing markets for small- and large-scale applications. 1, 2 To improve battery performance, there has …
The first ethylene molecule forms a 4-ethyl branch and the second a new terminal carbon-carbon double bond (C2 elongation). The key to this reaction is the …
Olefin, compound made up of hydrogen and carbon that contains one or more pairs of carbon atoms linked by a double bond. Olefins are important commercial petrochemicals and are produced through various methods, …
The photoisomerization of double bonds by E n T catalysis, initially proposed for styrenes but applicable to other functional groups such as Ar, Bpin, or C−C double bonds, typically proceeds via a Dexter mechanism 17 in which a photocatalyst in its triplet, photoexcited state populates the triplet state of the olefin (Figure 1a).
Liu and co-workers published their studies on oxidative cleavage of the C C double bond of olefins catalyzed by B 2 pin 2 ... Fenofibrate (5b), a blood-lipid lowering drug, was successfully synthesized from the corresponding olefin in 87% yield. In addition, Ibuprofen-derived substrate delivered target oxidation product 6b in 39% yield ...
In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond. The simplest acyclic alkenes, with only one double bond and no other functional groups, form a homologous series of hydrocarbons with the general formula C n H 2n.. The simplest alkene is ethylene (C 2 H …
Olefinic double bonds The highly regio- and diastereoselective addition of an alkyl and an arylthio group to an olefinic double bond ( carbosulfenylation ) is achieved with arenesulfenyl chlorides and alkyl-chloro-titanium(IV) species (Reetz reagent, from R2Zn/TiCU 5 1 M. T. Reetz, 1987, 1989), Use of the more bulky 2,4,6 …
The carbon–carbon double bond in olefins serves as a precursor to a rich array of transformations and is a cornerstone in the materials, pharmaceutical, agrochemical arenas, and food industry (1, 2) s construction in a selective and stereochemically defined manner—i.e., E versus Z olefin—is of utmost importance, as the geometry is ultimately …
The general formula of an acyclic olefin that contains one double bond (alkene) is C n H 2n. This implies that there are twice as many hydrogen atoms as carbon atoms in such olefins. For a cyclic olefin containing only one double bond, the general formula is C n H 2n-2. It can be noted that acyclic alkenes that only contain a single double bond ...
Some olefin diphosphine pincer ligands have been used to characterize details of TM–olefin chemistry, including an unusual reversible β-insertion of an olefin in a M–H bond that showed that ...
DOI: 10.26434/chemrxiv.13079603.v1 Corpus ID: 231874377; Selecting Double Bond Positions with a Single Cation-Responsive Iridium Olefin Isomerization Catalyst. @article{Camp2020SelectingDB, title={Selecting Double Bond Positions with a Single Cation-Responsive Iridium Olefin Isomerization Catalyst.}, author={Andrew M. Camp …
Carbon–carbon (C–C) bonds form the backbone of many important molecules, including polymers, dyes and pharmaceutical agents. The development of new methods to create these essential ...
1 H NMR spectroscopy is a powerful technique for establishing structural formulae of SARA fractions. As stated previously, the olefin content of petroleum oil is commonly measured using 1 H NMR spectroscopy [4], [7], [8].Original VR, 410°C-40 min-VR, and SARA fractions derived from both were characterized by 1 H NMR spectroscopy …
An exocyclic double bond in organic compounds refers to a double bond that is located outside of a ring structure. In organic chemistry, molecules can be classified into two main categories ...
The catalytic transposition of double bonds holds promise as an ideal route to alkenes with value as fragrances, commodity chemicals, and pharmaceuticals; yet, selective access to specific isomers is a challenge, requiring independent development of different catalysts for different products. In this work, a single cation-responsive iridium …
It is demonstrated for the first time that a bulk polymer could effectively heal via dynamic covalent bond formation at sub-ambient temperature and is potentially applicable to a wide range of olefin-containing polymers. In this article, we demonstrate transition-metal-catalyzed olefin metathesis as a simple, effective method for healing polymers via …
The carbon-carbon double bond in an alkene is responsible for the molecule''s chemical reactivity. For example, alkenes can undergo addition reactions, in which a molecule of hydrogen or another species is added to the double bond. Olefin Structure. The olefin molecule is a hydrocarbon that has a double bond between two carbon atoms.
DOI: 10.1016/J.MCAT.2016.12.018 Corpus ID: 100474214; Faster initiating olefin metathesis catalysts from introducing double bonds into cyclopropyl, cyclobutyl and cyclopentyl derivatives of Hoveyda-Grubbs precatalysts
New carbon–carbon bond formation reactions expand our horizon of retrosynthetic analysis for the synthesis of complex organic molecules. Although many methods are now available for the formation ...
The catalytic transposition of double bonds holds promise as an ideal route to alkenes of value as fragrances, commodity chemicals, and pharmaceuticals; yet, selective access to specific isomers is a challenge, normally requiring independent development of different catalysts for different products. In this work, a single cation-responsive iridium catalyst …
3 · Olefin Structure. Few Examples Showing Olefin Structure Are Given Below. The above-shown compounds are olefin compounds as they all have double bonds. The general olefin chemical structure is represented as >C=C< (Carbon-carbon double bond). The unsaturated carbons in the olefins are sp 2 hybridised. Types of Olefins. Aliphatic …
Olefin metathesis is a metal-catalyzed transformation, which acts on carbon-carbon double bonds and rearranges them via cleavage and reassembly [6 – 10]. …
Li et al. present a comprehensive summary of the total synthesis of natural products with a bridgehead olefin using 26 representative studies. Methods for constructing the bridged ring system and bridgehead double bond have been emphasized. ... Almost 100 years ago, the bridgehead double bond was first discussed and studied by chemists ...
There are three major routes for the heterogenization of olefin polymerization catalysts on solid supports: (Fig. 1, Route a) the introduction of a …
1. Introduction. The second generation Hoveyda-Grubbs catalyst 1, first synthesized in 2000, was one of the first efficient, phosphine-free ruthenium-based metathesis catalysts and which is still widely used today [1], [2].One of the most important advantages of 1 is the relative ease of introducing structural modifications to various …
The vast majority of double-bond migrations investigated over the past 60 years capitalize on precious-metal hydrides that are frequently associated with reversible …
The photoisomerization of double bonds by E n T catalysis, initially proposed for styrenes but applicable to other functional groups such as Ar, Bpin, or C−C double bonds, typically proceeds via a Dexter mechanism [17] in which a photocatalyst in its triplet, photoexcited state populates the triplet state of the olefin (Figure 1 a). This process is characterized …
Linear α-Olefins from Linear Internal Olefins by a Boron-Based Continuous Double-Bond Isomerization Process. Industrial & Engineering Chemistry Research …
Mechanism of Olefin Metathesis (exchange double bonds) Transalkylation RCHCHR'' RCHCHR RCH CHR R''CH CHR'' + Transalkylidenation R''CH CHR RCH CHR'' R''CH CHR'' RCH CHR + Actual ... Can''t polymerize cyclic alkene with R-substituent directly on C=C bond. Won''t undergo ROMP. CH Whereas will undergo ROMP. For bicyclics, (and …
The binding behavior of pillar[5]arenes (P5As) towards a series of olefin guests ((E)-1,4-dichlorobut-2-ene (1E), (Z)-1,4-dichlorobut-2-ene (1Z), (E)-but-2-ene-1,4-diol (2E), and (Z)-but-2-ene-1,4-diol (2Z), as well as an alkyne derivative 1,4-dichlorobut-2-yne (3)) have been studied in organic solution.P5As exhibit considerable selectivities for the …
One of the more distinctive aspects of double bond photoisomerization by E n T catalysis is its ability to work in tandem with other reactions. In these transformations, multiple …
Selecting Double Bond Positions with a Single Cation-Responsive Iridium Olefin Isomerization Catalyst Andrew M. Camp, Matthew R. Kita, P. Thomas Blackburn, Henry M. Dodge, Chun-Hsing Chen, and Alexander J. M. Miller* Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 –3290, United States
LINEALEN is a linear olefin with a double bond at the end, which is produced by polymerizing ethylene using our proprietary technology. There is a wide range of grades …
With the utilization of special polar comonomers bearing long spacers between the double bond and polar groups, very high activities (up to 2.32 × 10 6 g mol −1 h −1) and high copolymer ...
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