Air-tolerant C-C bond formation via organometallic ruthenium catalysis: diverse catalytic pathways involving (C5Me5)Ru or (C5H5)Ru are robust to molecular oxygen

Ruthenium-catalyzed substitutions of carbon pronucleophiles, various [2+2+2] cycloadditions, and addition of a diazo compound to an alkyne are shown to proceed in the presence of air. Notably diverse catalytic manifolds remain supported under conditions generally regarded as prohibitive. Building on rare reports from the literature we show that a range of organometallic transformations based on reaction intermediates derived from (C₅Me₅)Ru or (C₅H₅)Ru moieties are air-compatible.