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A carbanion is one of several reactive intermediates in organic chemistry. In organic synthesis, organolithium reagents and Grignard reagents are commonly treated and referred to as "carbanions." This is a convenient approximation, although these species are generally clusters or complexes containing highly polar, but still covalent bonds metal ...
In organic chemistry, methenium (also called methylium, carbenium, [2] methyl cation, or protonated methylene) is a cation with the formula CH + 3. It can be viewed as a methylene radical (: CH 2) with an added proton (H +), or as a methyl radical (• CH 3) with one electron removed.
Structure of methylenetriphenylphosphorane. Phosphonium ylides are used in the Wittig reaction, a method used to convert ketones and especially aldehydes to alkenes. The positive charge in these Wittig reagents is carried by a phosphorus atom with three phenyl substituents and a bond to a carbanion. Ylides can be 'stabilised' or 'non-stabilised'.
Structure of the 2-norbornyl non-classical carbenium ion. All other C-C bond lengths are normal (ca. 1.5 Å). [7] Carbonium ions can be thought of as protonated or alkylated alkanes, bearing the general formula CR 5 + (R = alkyl or H). A typical example is the methanium ion, CH 5 +, which is formed by protonation of methane using a superacid ...
In the reaction mechanism, there is 1 as the nucleophile: [3]. Deprotonation of 1 by a base leads to carbanion 2, stabilized by its electron-withdrawing groups.Structures 2a to 2c are three resonance structures that can be drawn for this species, two of which have enolate ions.
A carbenium ion is a positive ion with the structure RR′R″C +, that is, a chemical species with carbon atom having three covalent bonds, and it bears a +1 formal charge. Carbenium ions are a major subset of carbocations , which is a general term for diamagnetic carbon-based cations.
The anionic charge is delocalized over the oxygen and the two carbon sites. Thus they have the character of both an alkoxide and a carbanion. [5] Although they are often drawn as being simple salts, in fact they adopt complicated structures often featuring aggregates. [6] Structure of the lithium enolate PhC(OLi)=CMe 2 (tmeda) dimer. H atoms ...
The oxidation products derived from methyl are hydroxymethyl group −CH 2 OH, formyl group −CHO, and carboxyl group −COOH. For example, permanganate often converts a methyl group to a carboxyl (−COOH) group, e.g. the conversion of toluene to benzoic acid. Ultimately oxidation of methyl groups gives protons and carbon dioxide, as seen in ...