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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).
For example, protonation of methanol gives an electrophilic methylating reagent that reacts by the S N 2 pathway: CH 3 OH + H + → [CH 3 OH 2] + Similarly, methyl iodide and methyl triflate are viewed as the equivalent of the methyl cation because they readily undergo S N 2 reactions by weak nucleophiles. The methyl cation has been detected in ...
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.
Examples: dimethylsulfoxide, dimethylformamide, acetone, etc. In parallel, solvation also has a significant impact on the intrinsic strength of the nucleophile, in which strong interactions between solvent and the nucleophile, found for polar protic solvents, furnish a weaker nucleophile. In contrast, polar aprotic solvents can only weakly ...
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 ...
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 −).
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.
With a carbonyl compound as an electrophile, the nucleophile can be: [1] water in hydration to a geminal diol (hydrate) an alcohol in acetalisation to an acetal; a hydride in reduction to an alcohol; an amine with formaldehyde and a carbonyl compound in the Mannich reaction; an enolate ion in an aldol reaction or Baylis–Hillman reaction