a [Co-AA] was isolated from a raw mixture in toluene, while the reaction between AA and [Co2(CO)8] under argon was conducted in hexane. Both solvent are non coordinating solvents. It may be expected that the formation of [Co-AA] would be slowed down (or even hindered), in presence of a coordinating solvent (or a stabilizing ligand, like a diphosphine in our previous study, cf. Nicolas & Cantat, ChemCatChem 2023, 15, e202300720). a Conditions: AA (0.5 mol‧L -1 ) and mesitylene (internal standard, 10 mol%) with [Co2(CO)8] (5 mol%) in the solvent (2 mL), heated for 6 h under CO pressure. AA conversions and SA yields measured by GC-MS analysis; selectivity calculated as the ratio between yield and conversion. n.d.: not determined. Because of overlap with other peaks on the GC trace, the conversion may not always be measured.