oxonium ion

The propagating species is not a carbocation but an oxonium ion.

In chemistry, the oxonium ion is any oxygen cation with three bonds.

When the solvent is water, the intermediate is an oxonium ion.

Other oxonium ions are found when water is in solution with other solvents.

The intermediate oxonium ion is trapped by a nucleophile usually solvent.

Loss of water from this oxonium ion and subsequent deprotonation gives the ester.

Oxatriquinane and oxatriquinacene are unusually stable oxonium ions, first described in 2008.

For example, a protonated hydroxyl group is an oxonium ion, but not a hydronium.

A rearrangement reaction with ring expansion forms a more stable oxonium ion which is deprotonated.

It does not contain an oxonium ion component (flavylium cation), as anthocyanins do.

An oxonium ion is any ion with a trivalent oxygen cation.

The simplest oxonium ion is the hydronium ion H3O+.

Protonation of one of the hydroxyl groups of the activated complex gives a new oxonium ion.

This oxonium ion can readily add to the 4-hydroxyl group of a glucosyl residue on the 4 end of the glycogen chain.

These oxonium ions are powerful electrophiles, and react rapidly with a second molecule of alcohol to from new, stable compounds, called acetals.

The resulting oxonium ion 2 is activated towards nucleophilic attack and has a good leaving group, setting it apart from a normal carboxylic acid.

Oxonium ions normally are strong alkylating agents and are only observed in solution as reactive intermediates or under extreme conditions.

The effect is pervasive in certain amines, phosphines, sulfonium and oxonium ions, sulfoxides, and even carbanions.

The carbonyl reactant (2) is protonated by a protic acid and for the resulting oxonium ion 3 two resonance structures can be drawn.

This reaction step forms an oxonium ion which then reacts with the aromatic ring in a classical electrophilic aromatic substitution.

The rearrangement of acetone oxime in the Beckmann solution involves three acetic acid molecules and one proton (present as an oxonium ion).

Through anchimeric assistance, the iodine is displaced via another S2 reaction to give an oxonium ion (5), which is subsequently hydrolyzed to the give the mono-ester (6).

This intermediate rearranges to hyponitrous acid 6 (forming nitrous oxide 6c through 6b) and the oxonium ion 7 which loses a proton to form the carbonyl compound.

The hydroxyl group in 4 is protonated leading to the oxonium ion 6 which accepts a second alcohol group to 7 with a final deprotonation to the acetal 8.

Brookhart's acid is the salt of the diethyl ether oxonium ion and tetrakis[3,5-bis(trifluoromethyl)phenyl)borate (BAr').