Search results
Results from the WOW.Com Content Network
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 ...
Deprotonation by base (B-) to generate the phosphonate carbanion. The Horner–Wadsworth–Emmons reaction begins with the deprotonation of the phosphonate to give the phosphonate carbanion 1. Nucleophilic addition of the carbanion onto the aldehyde 2 (or ketone) producing 3a or 3b is the rate-limiting step. [12]
The benzyl cation or phenylcarbenium ion is the carbocation with formula C 6 H 5 CH + 2; the benzyl anion or phenylmethanide ion is the carbanion with the formula C 6 H 5 CH − 2. None of these species can be formed in significant amounts in the solution phase under normal conditions, but they are useful referents for discussion of reaction ...
An ylide (/ ˈ ɪ l aɪ d /) [1] or ylid (/ ˈ ɪ l ɪ d /) is a neutral dipolar molecule containing a formally negatively charged atom (usually a carbanion) directly attached to a heteroatom with a formal positive charge (usually nitrogen, phosphorus or sulfur), and in which both atoms have full octets of electrons.
Tetrahedron and octahedron metal cores formed by aggregation of the Li3 triangle - carbanion coordinate complex [5] Like other species consisting of polar subunits, organolithium species aggregate. [ 7 ] [ 14 ] Formation of aggregates is influenced by electrostatic interactions, the coordination between lithium and surrounding solvent molecules ...
It proceeds through a carbanion that attacks an endocyclic carbon and expels a leaving group (a halide) forming a bicyclic molecule with rings smaller than the original. The bicycle is then opened by nucleophilic attack on the ketone to give the contracted product. [19]
Typical route for alkylation of benzene with ethylene and ZSM-5 as a heterogeneous catalyst. Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents).
The reaction process begins with deprotonation at the halogenated position. [3] Because of the ester substituents, this carbanion is a resonance-stabilized enolate.This nucleophile next attacks the carbonyl reagent, forming a carbon–carbon bond.