Benutzer:Miskal/Tetraethylammonium trichloride

Strukturformel
Allgemeines
Name	tetraethylammonium trichlorid
Andere Namen	Mioskowski reagent
Summenformel	C8H20Cl3N
Externe Identifikatoren/Datenbanken
CAS-Nummer 13557-92-1
Eigenschaften
Molare Masse	236.61 g/mol
Aggregatzustand	solid
Sicherheitshinweise
GHS-Gefahrstoffkennzeichnung H- und P-Sätze H: EUH: P:
Soweit möglich und gebräuchlich, werden SI-Einheiten verwendet. Wenn nicht anders vermerkt, gelten die angegebenen Daten bei Standardbedingungen (0 °C, 1000 hPa).

Tetraethylammonium trichloride (also known as Mioskowski reagent) is an chemical compound with the formula [NEt₄][Cl₃] consisting of tetraethylammonium cations and trichloride anions and is used for chlorinations and oxidations.

Properties

At room temperature, tetraethylammonium trichloride is a yellow solid which is soluble in polar organic solvents (e.g., methylene chloride or acetonitrile). As it is a strong oxidant and chlorinating agent it is reacting with most organic solvents (see Applications).

Preparation

Commonly, tetraethylammonium trichloride is prepared by the reaction of tetraethylammonium chloride and elemental chlorine in methylene chloride at room temperature. After evaporation of the solvent, tetraethylammonium trichloride is obtained as a yellow solid.

${\ce {[NEt4]Cl + Cl2 -> [NEt4][Cl3]}}$

Recently, an alternative preparation of tetraethylammonium trichloride has been described using tetraethylammonium chloride and potassium peroxymonosulfate as oxidant.

Applications

In general, tetraethylammonium trichloride has a similar reactivity compared to elemental chlorine. As tetraethylammonium trichloride is a solid and can be dissolved in methylene chloride or acetonitrile, it is used as an easier to handle alternative to elemental chlorine, in particular for the synthesis of intermediates in natural product synthesis. Tetraethylammonium trichloride reacts with alkenes to the corresponding vicinal 1,2-dichlorinated alkanes and similarily with alkynes to the corresponding trans-dichlorinated alkenes. Electron rich arenes are chlorinated in para-position. While aldehydes are dichlorinated in alpha-position, ketones react to the monochlorinated alpha-chloroketones. In presence of 1,4-diazabicyclo[2.2.2]octane tetraethylammonium trichloride is a useful oxidant for the oxidation of primary alcohols to the corresponding aldehydes and of secondary alcohols to the corresponding ketones. For compounds bearing both a primary and a secondary alcohol, selective oxidation of the secondary alcohol is observed. Acetals undergo C-H chlorination of the tertiary C-H bond providing the corresponding chlorinated acetal.