O‐Benzylation of Carboxylic Acids Using 2,4,6‐Tris(benzyloxy)‐1,3,5‐triazine (TriBOT) under Acidic or Thermal Conditions

Abstract

AbstractTwo methods for the synthesis of benzyl esters from carboxylic acids using the O‐benzylating reagent 2,4,6‐tris(benzyloxy)‐1,3,5‐triazine (TriBOT) have been developed. The reactions were conducted either in the presence of a catalytic amount of TfOH at room temperature (acidic conditions) or in the absence of TfOH at 180–230 °C (thermal conditions). Interestingly, the O‐benzylation of hydroxy carboxylic acids under the two conditions afforded different products: The dibenzylated product under acidic conditions and the hydroxy ester under thermal conditions. In addition to these results, other evidence indicated that the former reaction proceeds through an SN1‐type mechanism, and the latter by an SN2‐type mechanism.