C–S bond cleavage of 2-methoxythiophene by Ir–TMEDA complex (TMEDA = N,N,N’,N’-tetramethylethylenediamine). Formation of novel dinuclear iridathiacyclohexenyl complex

The Ir–TMEDA complex [Ir(C2H4)2(TMEDA)(MeCN)][BF4] (TMEDA = Me2NCH2CH2NMe2) was treated with 2-methoxythiophene in MeCN at 70 °C in the presence of H2O to afford the novel dinuclear iridathiacyclohexenyl complex [Ir2{C(OMe)CHCHCH(CMedouble bond; length as m-dashNH)S}(MeCONH)(TMEDA)2][BF4]2 in 42% yield, in which two Ir(TMEDA) fragments, one 2-methoxythiophene, and two MeCN molecules are incorporated together with one H2O molecule. The mechanism that involves the insertion of the Ir center into the thiophenic S–C(OMe) bond followed by the π-coordination of the second Ir center to the thiametallacycle has been proposed.