Promoting C–C Coupling of 2-Methylfuran and Acetone by Tuning the Interaction of Reactants with a Catalyst

The C–C coupling reaction between 2-methylfuran (2-MF) and acetone to 5,5′-(propane-2,2-diyl)bis(2-methylfuran) (FADM) is a crucial step in synthesizing aviation kerosene and biomass-based monomers. This reaction is slow at low temperatures and overwhelmed by side reactions at high temperatures. In this work, we discovered a large improvement of FADM yield on the acid resin catalyst from 54.6% to 91.5% at high-temperature reaction (70 °C) by increasing the acetone concentration. Characterizations and theoretical calculations demonstrated that the acetone concentration tuned the interaction of reactants with the catalyst. The high acetone concentration favored its contact over that of water and 2-MF with acidic sites. Otherwise, water and 2-MF interacted with the catalyst markedly at low acetone concentrations, triggering side reactions.