REACTIONS OF DIHETEROARYL SULFOXIDES WITH HETEROARYLLITHIUMS - LIGANDCOUPLING AND EXCHANGE-REACTIONS

The reactions of heteroaryl sulfoxides with heteroaryllithiums gave va rious biheteroaryls and diheteroaryl sulfoxides as ligand coupling and ligand exchange products through sulfurane intermediates. Especially, the reaction of di-2-furyl sulfoxide with 2-pyridyllithium proceeded first by a ligand exchange reaction to form 2-furyllithium and 2-furyl 2-pyridyl sulfoxide, which then underwent ligand coupling with 2-pyri dyllithium to afford 2,2'-bipyridyl. Furthermore, if was found that th e occurrence of the Ligand coupling reaction depends on the stereoisom erism of the sulfurane intermediate formed. (C) 1996 John Wiley & Sons , Inc.