The cationic rhodium A-frame complex [Rh-2(mu-Cl)(CO)(2)(mu-CO)(mu-Ph2PCH2PPh2)(2)] is active as a hydroformylation catalyst at elevated temperature and pressure. In addition to the expected aldehydes, significant yields of linear and cyclic ketones are produced. Surprisingly, when the solvent is THF, but not methanol, carbonylation of styrene with cyclization to form 1-indanone also occurs, demonstrating the ability of the A-frame complex to non-photolytically activate a C-H bond. (C) 2002 Elsevier Science B.V. All rights reserved.