Evidence of Al ^II Radical Addition to Benzene

Electrophilic AlIII species have long dominated the aluminum reactivity towards arenes. Recently, nucleophilic low-valent AlI aluminyl anions showcased oxidative additions arenes C−C and/or C−H bonds. Herein, we communicate compelling evidence of an AlII radical addition reaction to benzene ring. The electron reduction a ligand stabilized precursor with KC8 in furnishes double ring instead bond activation, producing corresponding cyclohexa-1,3(orl,4)-dienes as Birch-type product. X-ray crystallographic analysis, EPR spectroscopy, and DFT results suggest this proceeds through stable intermediate, whose stability is consequence rigid scaffold combination strong steric protection.