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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 ...
In the context of a specific chemical reaction between NH 3 and Me 3 B, a lone pair from NH 3 will form a dative bond with the empty orbital of Me 3 B to form an adduct NH 3 •BMe 3. The terminology refers to the contributions of Gilbert N. Lewis. [2] The terms nucleophile and electrophile are sometimes interchangeable with Lewis base and ...
An application of HSAB theory is the so-called Kornblum's rule (after Nathan Kornblum) which states that in reactions with ambident nucleophiles (nucleophiles that can attack from two or more places), the more electronegative atom reacts when the reaction mechanism is S N 1 and the less electronegative one in a S N 2 reaction.
In S N 2 reactions, there are a few conditions that affect the rate of the reaction. First of all, the 2 in S N 2 implies that there are two concentrations of substances that affect the rate of reaction: substrate (Sub) and nucleophile. The rate equation for this reaction would be Rate=k[Sub][Nuc].
The bimolecular nucleophilic substitution (S N 2) is a type of reaction mechanism that is common in organic chemistry. In the S N 2 reaction, a strong nucleophile forms a new bond to an sp 3-hybridised carbon atom via a backside attack, all while the leaving group detaches from the reaction center in a concerted (i.e. simultaneous) fashion.
The strongly electrophilic nature of these compounds engendered by their attachment to extremely labile R−X (R = alkyl, X = Cl, Br, I) leaving groups is illustrated by their propensity to alkylate very weak nucleophiles. Heating neat samples of (CH 3) 2 Cl + [CHB 11 Cl 11] − under reduced pressure resulted in methylation of the very poorly ...
Conjugate addition is the vinylogous counterpart of direct nucleophilic addition. A nucleophile reacts with a α,β-unsaturated carbonyl compound in the β position. The negative charge carried by the nucleophile is now delocalized in the alkoxide anion and the α carbon carbanion by resonance.
Such nucleophile switches have occurred several times during evolutionary history, however the mechanisms by which this happen are still unclear. [17] [55] Within protease superfamilies that contain a mixture of nucleophiles (e.g. the PA clan), families are designated by their catalytic nucleophile (C=cysteine proteases, S=serine proteases).