Anagram & Information om | Engelska ordet CARBENE

Exempel på hur man kan använda CARBENE i en mening

• The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents).
• The term "carbene" may also refer to the specific compound , also called methylene, the parent hydride from which all other carbene compounds are formally derived.
• In this system, the standard Diels-Alder reaction is a (4 + 2)-cycloaddition, the 1,3-dipolar cycloaddition is a (3 + 2)-cycloaddition and cyclopropanation of a carbene with an alkene a (2 + 1)-cycloaddition.
• The enantiopurity of the chiral sulfoxide is preserved in the ultimate product after oxidation of the boronic ester to the alcohol indicating that a true carbene was never involved in the sequence.
• Grubbs catalysts are a series of transition metal carbene complexes used as catalysts for olefin metathesis.
• The π lone pair of the nitrogen stabilizes the structure and is responsible of the linearity of isocyanides, although the reactivity of isocyanides reflects some carbene character, at least in a formal sense.
• A transition metal carbene complex is an organometallic compound featuring a divalent carbon ligand, itself also called a carbene.
• The reaction is catalyzed by nucleophiles such as a cyanide or an N-heterocyclic carbene (usually thiazolium salts).
• The strong base deprotonates the vinylic hydrogen, which after alpha elimination forms a vinyl carbene.
• West later discovered the first example of a stable silylene, a form of divalent silicon, acting as the silicon analog to the now catalytically important carbene.
• The best-known examples and by far largest subgroup are the N-heterocyclic carbenes (NHC) (sometimes called Arduengo carbenes), in which nitrogen atoms flank the formal carbene.
• Silylenoids are the silicon pendants of carbenoid and both compounds have carbene or silylene like properties.
• Grubbs catalyst, a series of transition metal carbene complexes used as catalysts for olefin metathesis.
• Generally, under photolysis, compounds in the s-cis conformation react in a concerted manner due to the antiperiplanar relationship between the leaving and migrating groups, whereas compounds in the s-trans conformation react stepwise through a carbene intermediate or do not rearrange.
• Formally, removal of the two hydrogens at carbon 2 (between the two nitrogens) would yield the carbene dihydroimidazol-2-ylidene.
• An enyne metathesis is an organic reaction taking place between an alkyne and an alkene with a metal carbene catalyst forming a butadiene.
• This was initially thought to be an aromatic ylide, but is now believed to be a carbene In the presence of a strong electrophile, such as an aldehyde or ketone, this species will undergo nucleophilic attack faster than proton transfer.
• As opposed to the now ubiquitous NHC (N-heterocyclic carbene) systems based on imidazole rings, these carbenes are structured from triazole rings.
• When the cyclopropane ring is fitted with a 2-vinyl group, a cyclopentadiene is formed through a so-called foiled carbene intermediate.
• Carbenes prepared by other methods such as diazo compounds, might exhibit properties better attributed to the diazo compound used to make the carbene (which mimic carbene behaviour), rather than to the carbene itself.

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