Convenient and Simple Esterification in Continuous-Flow Systems using g-DMAP

The utility and applicability of polyethylene-g-polyacrylic acid-immobilized dimethylaminopyridine (g-DMAP) as a catalyst in a continuous-flow system were investigated for decarboxylative esterification. High catalytic activity toward acylation was provided by g-DMAP containing a flexible grafted-polymer structure. During decarboxylation, carboxylic acids and alcohols were converted cleanly using di-tert-butyl dicarbonate (Boc(2)O) as a coupling reagent, which reduced by-products. In addition, the use of Boc(2)O resulted in the formation of tert-butyl esters. These esterifications dramatically reduced the reaction time under continuous-flow conditions, with a residence time of approximately 2min. This highly efficient esterification procedure will provide more practical industrial applications.