Catalyst-free Synthesis of Biodiesel Precursors from Biomass-based Furfuryl Alcohols in the Presence of H2O and Air

Production of biodiesel from biomass resources usually requires elongation of carbon numbers from typical C-5 and C-6 platform molecules through C-C coupling reactions, which were catalyzed by acid, base or metal catalysts traditionally. Herein, a catalyst-free method was developed to produce bis(furan-2-yl)methane derivatives (BFMs) from furfuryl alcohol derivatives (FAs) in the presence of H2O and air without any other additional catalysts. An 81% yield of bis(5-methylfuran-2-yl)methane (BMFM) can be obtained from 5-methylfurfuryl alcohol (5-MFA) and a 59% total yield of C-11 biodiesel was obtained from 5-methylfurfural (5-MF). In addition, a H2O and air mediated free radical decarboxylation mechanism was proposed based on the detailed mechanistic studies. This strategy offers a green, low-cost and environmentally friendly approach to synthesize biodiesel precursors from biomass based platform molecules.