Cyclometallated ruthenium(ii) complexes with ditopic thienyl–NHC ligands: syntheses and alkyne annulations

Abstract

A series of six [RuX(2-thienyl–NHC)(p-cymene)] complexes (9a–c and 10–14; X = halido) have been prepared via NHC directed C–H activation. All complexes have been fully characterized, and the molecular structures of four complexes are reported. The rotational barrier of the N-benzyl substituent in the bromido complex 9b has been measured by variable temperature ¹H NMR spectroscopy. Preliminary reactivity studies of complex 12 with alkynes provided four new annulated aza-heterocyclic thiophenes.