Palladium-Catalyzed Reactions of [Et3NH]+ Salts of [(μ-RS)(μ-CO)Fe2(CO)6]− Anions with Iodo-Aromatic Compounds To Give the Corresponding Butterfly μ-Acyl Fe/S Cluster Complexes

Abstract

Interestingly, the intermediate salts A·[Et3NH] (A = (μ-RS)(μ-CO)Fe2(CO)6; R = i-Pr, sec-Bu, cy-C6H11, p-MeC6H4) prepared from Fe3(CO)12, RSH, and Et3N were found to react in situ with iodobenzene or its substituted derivatives in the presence of the catalyst precursor Pd(PPh3)4 to give the benzoyl type μ-acyl complexes (μ-RS)(μ-ArCO)Fe2(CO)6 (Ar = phenyl or substituted phenyl), whereas the in situ reactions of A·[Et3NH] with iodo-substituted aromatic heterocycles under the same conditions afforded the corresponding heterocyclic type μ-acyl complexes (μ-RS)(μ-ArCO)Fe2(CO)6 (Ar = heterocyclic or benzoheterocyclic group). Particularly worth noting is that such Pd-catalyzed C–C bond cross-coupling reactions are the first examples of catalytic reactions regarding A·[Et3NH] salts reported so far. In addition, all the prepared new μ-acyl complexes and the three new intermediate salts A·[Et3NH] (R = i-Pr, sec-Bu, cy-C6H11) were isolated and structurally characterized, while a possible pathway for such type Pd-catalyzed reactions regarding A·[Et3NH] salts is suggested.