Traditional methods for regioselective enolate formation use either electronic activating groups (e.g. aldehydes) or steric blocking groups (e.g. 1,2-ethanedithiol protected ketone). An enone can also serve as a precursor for regiospecific formation of an enolate, here the enone is a "masked functionality" for the enolate.

2022年8月16日 · When an additional electron-withdrawing group is present on the alpha-carbon, enolates become much easier to form. Enolates are nucleophiles and have many useful reactions with electrophiles. In this post we will cover the reactions of enolates with H+ , halogens, and simple electrophiles.

Some bases that have been used for enolate anion formation are: NaH (sodium hydride, pK a > 45), NaNH 2 (sodium amide, pK a = 34), and LiN[CH(CH 3) 2] 2 (lithium diisopropylamide, LDA, pK a 36). Ether solvents like tetrahydrofuran (THF) …

Five factors that influence the relative proportion of keto/enol: 1. Aromaticity. Answer: The more electron-poor the carbonyl, the greater will be its ability to stabilize negative charge. Conversely, the greater the donating ability of a substitutent on the carbonyl, the less it will be able to stabilize negative charge. 2.

An enol is a species featuring a carbon-carbon double bond (alkene) that is directly connected to a hydroxyl group (-OH), while a ketone contains a carbonyl group (C=O) bonded to two carbon atoms and an aldehyde contains a carbonyl group bonded to at least one hydrogen atom.

Functional groups, such as aldehydes, ketones and esters, contain a carbonyl group which is made up of a sp 2 hybridized carbon and oxygen. Because they are sp 2 hybridized the carbon and oxygen both have un hybridized p orbitals which can overlap to form the C=O π π bond.

Enols and certain corresponding aldehydes or ketones are tautomers, which are forms that differ only by way of a movement of an atom or functional group. Note that the enol form of 3-pentanone is formed by moving the hydrogen atom from the ? …

In the enolate, the molecular orbital description changes slightly due to the presence of an electronegative oxygen atom. This molecular orbital description tells you a few things: 1) the total charge (ψ ψ 1 + ψ ψ 2) is greater on oxygen than on carbon, but 2) in the HOMO, the charge is greater on carbon.

Enolates, also known as oxyallyl anions, are flexible reagents that may be used to make -substituted carbonyl compounds, making them crucial intermediates in the synthesis of complex molecules.

In aqueous solution, an aldehyde or ketone which has an alpha type hydrogen can lose it to water, giving hydronium ion and the conjugate base of the carbonyl compound, which is called an enolate. This C-H bond is significantly less acidic than the O-H bond of an alcohol and much less acidic than the O-H bond of a carboxylic acid.