Epoxides are versatile chemical intermediates that can be conveniently synthesized from alkenes.1
Opening of the epoxide ring can be achieved with various nucleophiles like water, alcohols, amines, and thiols yielding synthetically important di-substituted compounds.2â5
Although heterogeneous acids and bases are known to catalyze this reaction, limitations like low selectivity and/or low stability can limit their scope.6â8
In this work we have studied silica-based Lewis acidic catalysts with varying pore-sizes and Lewis acid-site strength. We report that these catalysts can selectively open the epoxide ring using alcohols under mild conditions for different systems including epichlorohydrin-methanol. Systematic investigations of the effect of acid site strength, temperature, and pore-confinement of these materials revealed that these factors affect the catalytic activity but not the regioselectivity. In case of straight chain mono-functional epoxides, the regioselectivity increases with an increase in nucleophile size. Overall, we have studied catalytic performance and reusability of different silica-based Lewis acidic catalysts for epoxide ring opening with alcohols.
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