Formation of imidazolidine-benzothiazole–copper(ii) complexes via a copper-mediated room-temperature C–H activation of imidazolidinecarbothioamides

Abstract

Treatment of N-aryl-2-(arylimino)imidazolidine-1-carbothioamide, and unsymmetrical thiourea, with copper(II) chloride or bromide results in aryl sp² C–H activation (C–S bond formation) at room temperature to form a 2-[2-(arylimino)imidazolidin-1-yl]benzothiazole with concurrent formation of a 2-imidazolidin-1-ylbenzothiazole–copper(II) complex. In all the complexes the imine and benzothiazole nitrogens are s-cis, whereas in the isolated ligands they are s-trans oriented. Due to the presence of a suitable H-donor site and halogen atoms in the metal complexes and ligands, several supramolecular assemblies exist through H-bonding interactions; classical N–H•••X–Cu (F, Cl, Br), nonclassical C–H•••X–Cu H–bonds and halogen•••π and halogen•••halogen interactions.