Carboxylation and Esterification of Functionalized Arylcopper Reagents

Key words

aryl iodides - organocopper - carboxylation

Significance

The synthesis of substituted benzoate esters from aryl iodides was performed using the insertion of active copper metal, generated from CuI-PEt₃ complex and lithium naphthalenide, followed by the carboxylation with CO₂. The method allows preparing a number of aryl benzoates, bearing functional groups which are not compatible with standard organomagnesium chemistry.

Comment

Insertion of copper is a very mild method for the formation of organometallic species from aryl iodides, since it is compatible with practically any functionality. A certain drawback of arylcopper species is a lack of reactivity toward electrophiles. The given method of acid and ester formation from arylcopper by the carboxylation-alkylation sequence is preferable, giving higher yields than the conventional reaction with chloroformates.