Synthesis of 3-Carbonyl Trisubstituted Furans via Pd-Catalyzed Aerobic Cycloisomerization Reaction: Development and Mechanistic Studies

Herein, we report the synthesis of 3-carbonyltrisubstituted furans via Pd-catalyzed oxidative cycloisomerization reactions of 2-alkenyl-1,3-dicarbonyl scaffolds, using molecular oxygen as the sole oxidant to regenerate active palladium catalytic species, featuring good functional tolerance and mild reaction conditions. Deep investigation of intermediates and transition states of the reaction mechanism were conducted via experimental and DFT studies, providing a detailed mechanistical profile. The new developed methodology presents a greener alternative to Wacker-type cycloisomerizations and avoids the use of stoichiometric amounts of oxidants and strong acid additives.

Automated summary

In this study, a new synthesis method for 3-carbonyltrisubstituted furans through Pd-catalyzed oxidative cycloisomerization reactions was reported. The use of molecular oxygen as the sole oxidant provides good functional tolerance and mild reaction conditions, while avoiding the need for stoichiometric amounts of oxidants and strong acid additives. Deep investigation of intermediates and transition states of the reaction mechanism was performed, providing a detailed mechanistical profile.