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A hydroxide ion acting as a nucleophile in an S N 2 reaction, converting a haloalkane into an alcohol. In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they ...
Butyllithium is a strong base (pK b ≈ -36), but it is also a powerful nucleophile and reductant, depending on the other reactants. Furthermore, in addition to being a strong nucleophile, n -BuLi binds to aprotic Lewis bases, such as ethers and tertiary amines , which partially disaggregate the clusters by binding to the lithium centers.
As a reagent in organic chemistry, DBU is used as a ligand and base. As a base, protonation occurs at the imine nitrogen. [5] Lewis acids also attach to the same nitrogen. [6] These properties recommend DBU for use as a catalyst, for example as a curing agent for epoxy resins and polyurethane.
tert-Butoxide, on the other hand, is a strong base, but a poor nucleophile, because of its three methyl groups hindering its approach to the carbon. Nucleophile strength is also affected by charge and electronegativity : nucleophilicity increases with increasing negative charge and decreasing electronegativity.
This relationship is according to the equation ΔG = –RT ln K (Gibbs free energy). The rate equation for S N 2 reactions are bimolecular being first order in Nucleophile and first order in Reagent. The determining factor when both S N 2 and S N 1 reaction mechanisms are viable is the strength of the Nucleophile. Nuclephilicity and basicity ...
Phenylmagnesium bromide is a strong nucleophile as well as a strong base. It can abstract even mildly acidic protons, thus the substrate must be protected where necessary. It often adds to carbonyls, such as ketones, aldehydes. [1] [3] With carbon dioxide, it reacts to give benzoic acid after an acidic workup.
Diisopropylamine is a common amine nucleophile in organic synthesis. [4] Because it is bulky, it is a more selective nucleophile than other similar amines, such as dimethylamine. [5] It reacts with organolithium reagents to give lithium diisopropylamide (LDA). LDA is a strong, non-nucleophilic base [6]
The phenoxide anion (aka phenolate) is a strong nucleophile with a comparable to the one of carbanions or tertiary amines. [3] Generally, oxygen attack of phenoxide anions is kinetically favored, while carbon-attack is thermodynamically preferred (see Thermodynamic versus kinetic reaction control). Mixed oxygen/carbon attack and by this a loss ...