C–H activation of benzene with Cp∗Ru(CO)2CH3

Irradiation of Cp∗Ru(CO)2CH3 (1) in C6D6 at room temperature yields Cp∗Ru(CO)2C6D5 and CH3D (where Cp∗ = n5-C5Me5). Cp∗Ru(CO)2CD3 (2) has also been prepared and similar irradiation in C6H6 yields Cp∗Ru(CO)2C6H5 (3) and CD3H. This latter reaction confirms that it is the methyl group bonded to ruthenium that is involved in the C–H activation process and not the methyl groups on the Cp∗ ligand system. The compound Cp∗Ru(CO)2C6H5 (3) has been prepared for the first time in good yield by the reaction of Cp∗Ru(CO)2Br with NaBPh4. X-ray crystal structures of both Cp∗Ru(CO)2CH3 (1) and Cp∗Ru(CO)2C6H5 (3) have been determined and the results are reported and discussed.