C−H Bond Activation of Benzene and Cyclic Ethers by TpIrIII Species

Investigations on the Coupling of Ethylene and Alkynes in [IrTp] Compounds: Water as an Effective Trapping Agent

“…This is in agreement with the known decreased reactivity of the TpIr compounds, as compared with the related Tp Me2 Ir ones, in activation processes. In the Tp Me2 Ir system we have observed cases in which C 2 H 4 easily inserts into an Ir-C bond, for example in its reaction with Tp Me2 Ir(C 6 H 5 ) 2 (N 2 ), [17] but also found complexes that are unreactive in this respect, as the iridacyclopentene Tp Me2 Ir(CH 2 C(Me)=C(Me)CH 2 )(C 2 H 4 ) which, upon heating, dissociates the coordinated ethylene; [18] or the very reactive Tp Me2 Ir(H)(CH=CH 2 )(C 2 H 4 ), which has been shown to yield a C 4 chain by the coupling of the two C 2 ligands, although by following a mechanistic pathway different from the insertion of ethylene into the Ir-C bond. [9] The water ligand in 8 is also labile and the corresponding adducts 8·NCMe and 8·CO are easily obtained [Eq.…”