Biocatalytic Silylation: The Condensation of Phenols and Alcohols with Triethylsilanol

From MDPI via Jisc Publications RouterHistory: accepted 2021-07-20, pub-electronic 2021-07-22Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; Grant(s): EP/S013539/1, EP/M506436/1Funder: Biotechnology and Biological Sciences Research Council; Grant(s): BB/L013649/1, BB/J014478/1, BB/M017702/1Funder: Tertiary Education Trust Fund; Grant(s): Graduate ScholarshipSilicatein-α (Silα), a hydrolytic enzyme derived from siliceous marine sponges, is one of the few enzymes in nature capable of catalysing the metathesis of silicon–oxygen bonds. It is therefore of interest as a possible biocatalyst for the synthesis of organosiloxanes. To further investigate the substrate scope of this enzyme, a series of condensation reactions with a variety of phenols and aliphatic alcohols were carried out. In general, it was observed that Silα demonstrated a preference for phenols, though the conversions were relatively modest in most cases. In the two pairs of chiral alcohols that were investigated, it was found that the enzyme displayed a preference for the silylation of the S-enantiomers. Additionally, the enzyme’s tolerance to a range of solvents was tested. Silα had the highest level of substrate conversion in the nonpolar solvents n-octane and toluene, although the inclusion of up to 20% of 1,4-dioxane was tolerated. These results suggest that Silα is a potential candidate for directed evolution toward future application as a robust and selective biocatalyst for organosiloxane chemistry