A mesoporous organosilica grafted Pd catalyst (MOG-Pd) for efficient base free and phosphine free synthesis of tertiary butyl esters via tertiary-butoxycarbonylation of boronic acid derivatives without using carbon monoxide

Abstract

A mesoporous organosilica grafted palladium(II) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the synthesis of tertiary butyl esters via tert-butoxycarbonylation of boronic acid derivatives. The tertiary butyl esters were obtained directly from boronic acid pinacol esters and di-tert-butyl dicarbonate. The reaction was optimized by varying the bases, temperatures and solvents. The catalyst was very stable and could be facilely recovered and reused six times with no significant decrease in its activity and selectivity.