Regioselectivity in C–H activation: Reactions of N-heterocyclic indenes with Ru3(CO)12

Thermal treatment of Ru3(CO)12 with 3-(6-ethyl-2-pyridyl)indene in refluxing toluene gave a triruthenium carbonyl complex {μ2-η5:η1-(C2H5C5H4N)(C9H5)}Ru3(CO)9 (1) via regioselective C(sp2)–H activation. While reaction of 2-methyl-3-(6-ethyl-2-pyridyl)indene with Ru3(CO)12 generated a dinuclear ruthenium complex {(C2H5C5H4N)(μ2-η5,η1-C9H5CH2)}Ru2(CO)5 (2) via regioselective C(sp3)–H bond activation. When the pyridyl rings were replaced by more bulky quinolinyl rings, only η5-indenyl ruthenium complexes were produced. The molecular structure of 2 was determined by X-ray diffraction analysis.