Catalytic Upgrading in Bacteria-Compatible Conditions via a Biocompatible Aldol Condensation

Integrating nonenzymatic chemistry with living systems has the potential to expand greatly the types and yields of chemicals that can be sourced from renewable feedstocks. The in situ conversion of microbial metabolites to higher order products will ensure their continuous generation starting from a given cellular reaction mixture. We present here a systematic study of different organocatalysts that enable aldol condensation in biological media under physiological conditions of neutral pH, moderate temperature, and ambient pressure. The relative toxicities of each catalyst were tested against bacteria, and the catalysts were found to provide good yields of homoaldol products in bacterial cultures containing aldehydes. Lastly, we demonstrate that a biocompatible oil can be used to extract selectively the upgraded products, which enabes facile isolation and decreases the product toxicity to microbes.