Ru3(CO)12-Catalyzed C−H/CO/Olefin Coupling of N-Pyridylindolines. Direct Carbonylation at a C−H Bond δ to the Pyridine Nitrogen

The reaction of N-pyridylindolines with CO and ethylene in the presence of Ru3(CO)12 results in direct carbonylation at a C−H bond δ to the pyridine sp2 nitrogen, which represents a new type of C−H/CO/olefin coupling. The presence of a pyridine ring as a directing group on the substrates is essential for the reaction to proceed. The choice of N,N-dimethylacetamide (DMA) as the solvent is crucial for the reaction to proceed efficiently.