Oxidative Coupling of 2-methyl furoate: a scalable synthesis of Dimethyl 2,2'-bifuran-5,5'-dicarboxylate

Abstract We report an investigation of the homogeneous Pd-catalyzed oxidative homocoupling of methyl 2-furoate with molecular oxygen as oxidant. Conditions were identified that produce acceptable yield (11.4 %), good selectivity (85 %) and ultra-high turn-over-frequency (TOF, 544 h−1). The product, dimethyl 2,2′-bifuran-5,5′-dicarboxylate, precipitates in nearly pure form upon cooling the reaction mixture. Kinetic and mechanistic investigations showed the reaction followed the so-called bimetallic mechanism.