Pd(OAc)2 Catalyzed Ligand and Base free Synthesis of Symmetrical diaryl Ketones via Carbonylative Selfcoupling of Aryldiazonium Tetrafluoroborate at Room Temperature

An efficient, economical, and environmentally benign protocol for the synthesis of symmetrical diaryl ketones has been developed via carbonylative selfcoupling of aryldiazonium tetrafluoroborate salts under ligand and base-free conditions. In this transformation, readily accessible diazonium tetrafluoroborate salts-easily derived from abundant and cheap anilines-serve as powerful electrophilic partners, eliminating the necessity for any external nucleophile. This electrophile-driven strategy represents a fundamentally new method for the synthesis of symmetrical diaryl ketones without the need of any ligand and base at room temperature. Notably, the methodology works under mild and operationally simple conditions, thereby offering an atom-economical and energy-efficient process. A broad substrate scope is demonstrated, showing excellent tolerance toward diverse functional groups and affording the corresponding symmetrical diaryl ketones in good to excellent yields. The exclusive employment of aryl tetrafluoroborate salts as electrophiles undergoing carbonylative selfcoupling in the absence of ligand and base at ambient temperature, highlighting the advancement, new approach, and sustainability of this protocol. Overall, this strategy offers a practical, simple, benign, economical, and green alternative for the construction of symmetrical ketones and expands the synthetic utility of aryldiazonium tetrafluoroborate salts in carbonylative selfcoupling chemistry.