General and Efficient Transesterification ofβ-Keto Esters with Various Alcohols Using Et3N as a Brønsted Base Additive

Expedient approach for trans-esterification of β-keto esters under solvent free conditions using silica supported boric acid (SiO2-H3BO3) as a recyclable catalyst

A highly efficient trans-esterification of β-keto methyl/ethyl esters with primary, secondary, allylic, benzylic and chiral alcohols has been carried out in excellent yields under solvent-free conditions using silica supported boric acid as a heterogeneous catalyst. The surface morphology of the silica-boric acid catalyst (fresh and recycled) has been characterized by SEM and EDX techniques. This sustainable protocol resulted in a remarkable enhancement in the synthetic efficiency (87–95% yield) with high purity and eliminating the use of an environmentally toxic solvent. The work up procedure is very simple and the catalyst has been successfully recovered and recycled. The present methodology is also applicable for trans-esterification with chiral alcohols on a multi-gram scale without compromising the yield. Noteworthy features of this protocol are simple operational procedure, minimizing production of chemical waste, mild reaction conditions, easy preparation of the catalyst and its recyclability up to five cycles without any appreciable loss of catalytic activity.

A simple, mild, high yielding and minimizing chemical waste procedure for trans-esterification of β-keto methyl/ethyl esters with alcohol groups was developed under solvent-free condition using silica-boric acid as recyclable heterogeneous catalyst.

Recent advances in the transesterification of β-keto esters

The ability to selectively transesterify β-keto esters is a useful transformation in organic synthesis. The increasing interest in transesterification for the synthesis of compounds of pharmaceutical importance, as well as for biodiesel production, has led to the development of a variety of different approaches. This article aims to summarise recent advances in the transesterifications of β-keto esters. Particular interest has been paid to methodologies with minimal environmental impact.

This review summarises the many advances in the selective transesterification of β-keto esters, with a particular focus on the past 30 years.