Insertion of iridium into C-H and C-S bonds of 2,5-dimethylthiophene, 2-methylbenzothiophene and 4,6-dimethyldibenzothiophene

C-H insertion thienyl products are selectively formed at early times of the interaction of the unsaturated 16e- fragment [,(triphos)IrH] with 2,5-dimethylthiophene (Me2T), 2-methylbenzothiophene (MeBT) and 4,6-dimethyldibenzothiophene (MezDBT} [triphos = MeC(CHzPPh2)3]. C-S insertion to give six-membered metallathiacycle products occurs as a thermal step only for MezT and MeBT. The C-S insertion products are isolated as both kinetic and thermodynamic stereoisomers. The thermodynamic C-S insertion product of MeBT, endo-[(triphos)Ir(@-S,C,C-S(C6H4)CH=C(Me)H)], has been characterized by X-ray diffraction studies.