Transition metal free oxidative esterification of alcohols with toluene
Using Bu4NI as the catalyst and tert-butyl hydroperoxide as the oxidant, direct esterification of alcohols with toluene derivatives was achieved. Mechanistic investigations indicate that the alcohols are sequentially oxidized to aldehydes, carboxylic acids, and then to benzyl esters. Bu 4N+ functions as a phasetransfer reagent and iodide catalyzes the reaction.
Palladium-catalyzed benzylation of carboxylic acids with toluene via benzylic C-H activation
Direct benzylation of carboxylic acids with toluene has been developed via palladium-catalyzed C-H acyloxylation under 1 atm of oxygen. This reaction demonstrates good functional group tolerance and high yields, providing a facile, atom-economic, and efficient method for the synthesis of benzyl esters.