(349i) Catalytic Site Design for Lewis Acid Zeolites for the Epoxide Ring Opening with Alcohols

Epoxides are important intermediates that are commonly ring opened using various nucleophiles to produce valuable bifunctional chemicals. The key challenge for this reaction is regio and enantioselectivity. Indeed, the ring opened epoxide can form aldehyde and oligomeric byproducts. Additionally, the conversion of terminal epoxides offer additional selectivity challenges since the reaction can form either a terminal ether or a terminal alcohol, resulting in low regioselectivity. In general, it has been recognized that Bronsted acidic catalyst results in low regioselectivity. Higher regioselectivity has been observed for Lewis acidic catalysts such as Co-Salen and Co-Porphyrin, but these catalysts have been found to deactivate. In this work, we will discuss the regioselective epoxide ring opening reaction with alcohols for Lewis acidic catalytic materials. Our initial work has elucidated that Sn-Beta is the most active heterogeneous Lewis acid catalyst of the materials tested. Additional work showed that diffusion limitations could be overcome through synthesizing nano-zeolites. In this presentation, we further elucidation structure-function relationships that are important to achieve high catalytic activity and selectivity. Overall, these materials are highly active and selective catalysts for the alcohol ring opening of epoxides.