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The carbonylation of methanol with carbon monoxide to methyl formate (methyl methanoate) is catalyzed by strong bases, such as potassium methoxide. [ 7 ] [ 8 ] The main application of potassium methoxide is use as basic transesterification catalyst in biodiesel synthesis (as a 25-32% methanolic solution).
The nucleophile may be electrically neutral or negatively charged, whereas the substrate is typically neutral or positively charged. An example of nucleophilic substitution is the hydrolysis of an alkyl bromide , R-Br under basic conditions, where the attacking nucleophile is hydroxyl ( OH − ) and the leaving group is bromide ( Br − ).
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 ...
Because of the capture of the nucleophile (R •), methyl has oxidising character. Methyl is a strong oxidant with organic chemicals. However, it is equally a strong reductant with chemicals such as water. It does not form aqueous solutions, as it reduces water to produce methanol and elemental hydrogen: 2 CH • 3 + 2 H 2 O → 2 CH 3 OH + H 2
The methoxide anion, for example, is both a strong base and nucleophile because it is a methyl nucleophile, and is thus very much unhindered. 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.
The terms nucleophile and electrophile are sometimes interchangeable with Lewis base and Lewis acid, respectively. These terms, especially their abstract noun forms nucleophilicity and electrophilicity , emphasize the kinetic aspect of reactivity, while the Lewis basicity and Lewis acidity emphasize the thermodynamic aspect of Lewis adduct ...
The resulting thiolate anion is a strong nucleophile. It can be oxidized to dimethyl disulfide: 2CH 3 SH + [O] → CH 3 SSCH 3 + H 2 O. Further oxidation takes the disulfide to two molecules of methanesulfonic acid, which is odorless. Bleach deodorizes methanethiol in this way.
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.