1,3‐Butadienyl Dianions as Non‐Innocent Ligands: Synthesis and Characterization of Aromatic Dilithio Rhodacycles

Abstract

Herein we report that 1,4-dilithio-1,3-butadienes, at ype of 1,3-butadienyl dianion, can act as non-innocent ligands,t aking electrons from low-valent transition metals. Dilithio reagents reacted with [{RhCl(cod)} 2 ]t og ive dilithio rhodacycle 3a.S ingle-crystal X-rays tructural analysis revealed the structure of 3a with averaged bond lengths.X PS data suggested that the oxidation state of Rh in 3a was more likely to be Rh 3+ .CDA/ECDAconfirmed the electron-transfer process. 7 Li NMR spectra of 3a and theoretical calculations revealed aconsiderable aromatic character.Inthis process,the dilithio compounds behaved as non-innocent ligands and formal oxidants.T hese results demonstrated that organolithium compounds with suitable p-conjugation could be used as electron acceptor.