Aryne-mediated direct assembly of O-bridged seven-membered cyclic diaryliodoniums: access to oxaheteropines and cannabinols via skeletal modification.

Cyclic diaryliodonium salts are versatile intermediates for the synthesis of functionalized aromatic compounds and polycyclic systems. Their preparation, however, typically relies on oxidative cyclization of preorganized iodoaryl-aryl frameworks, and medium-sized cyclic diaryliodoniums remain largely underexplored within this synthetic paradigm. Here we report an aryne-mediated direct assembly of O-bridged seven-membered cyclic diaryliodoniums from (pseudo)cyclic diaryliodoniums bearing an O-nucleophilic benzyl alcohol-derived ligand and a dummy 2,4,6-trimethoxyphenyl ligand. The transformation involves aryne engagement of the oxygen and intramolecular ambiphilic capture by the iodine(iii) center, followed by protonation of the dummy ligand to furnish the cyclic diaryliodonium products. These cyclic diaryliodoniums serve as versatile platforms for skeletal modification, enabling access to oxaheteropine frameworks through iodine replacement and a concise synthesis of cannabinol via iodine deletion.