Ultrasound-Promoted Coupling of Aryl and Heteroaryl Halides in the Presence of Lithium Wire. Formation of Dimeric and Dehalogenated Products

Article abstract of DOI:10.1007/BF00809805

Although sonochemical reactions of bromobenzene and of 2-, 3- and 4-halogenopyridines with lithium wire in THF solution yield the expected dimers, considerable dehalogenation also occurs, as monitored by 13C-NMR spectroscopy.A pathway for the unusual formation of 4,4'-bipyridyl from the 2-halogenopyridines is proposed.No dimers were detected from the reactions with 2-bromo-4-methylquinoline and 7-bromo-2,4-dimethylquinoline.The synthetic potential of their alternative facile sonochemical dehalogenation is propounded.Keywords.Ultrasound; Sonochemistry; Bipyridines; 13C-NMR Spectroscopy.