Synthesis of tricarbonyl η6- and η5-[(3-thiophenyl)organo]chromium and -manganese complexes

Abstract The syntheses of tricarbonyl η 6 -[(3-thiophenyl)arene]chromium 1a , 1b and η 5 -[(3-thiophenyl)cyclohexadienyl]manganese complexes 2 are reported using a Stille cross-coupling methodology. A two-step strategy involving a Stille reaction– exo -hydride abstraction sequence allowed selective access to cationic tricarbonyl η 6 -[(3-thiophenyl)arene]manganese complex 3 . 1 H-NMR data of these 3-thiophenylchromium and manganese complexes are presented as well as a comparison with the corresponding 2-thiophenyl-substituted derivatives described in the literature. The crystal structure determinations of 3-thiophenyl and 2-thiophenyl-η 6 -(arene)Cr(CO) 3 complexes showing the conformations of the Cr(CO) 3 tripods are also reported.