Renewable synthesis of novel acrylates from biomass-derived 5-substituted-2-furaldehydes by Morita-Baylis-Hillman reaction

Biomass-derived furfurals are becoming increasingly popular as renewable chemical building blocks for synthesizing specialty chemicals. Morita-Baylis-Hillman (MBH) reaction is a classic carbon-carbon bond-forming transformation between the alpha-position of an activated alkene and a carbon electrophile (e. g., aldehyde) using a nucleophilic catalyst, such as a tertiary amine or phosphine. The MBH reaction is highly atom economical, affords excellent yields of adducts under mild reaction conditions, introduces substantial molecular complexity, and enjoys broad substrate scope. In this work, several novel MBH adducts have been synthesized starting from biomass-derived 5-substituted-2-furaldehydes and acrylates using 1,4-diazabicyclo[2.2.2]octane (DABCO) as the organocatalyst. This work reports the first systematic study of the MBH reaction of 5-substituted-2-furaldehydes and acrylates. A general synthetic protocol for the high-yielding synthesis of MBH adducts has been developed. The reactions were performed at room temperature under solvent-free conditions, and the spectroscopically pure products were produced in good to excellent isolated yields. Moreover, DABCO was recovered from the reaction mixture and successfully recycled.