We then turned our attention towards acrylic acid (AA), and isomer of PL and a platform chemical with millions of tons in global production volumes. Carbonylation of AA has been attempted by Tsuji et al. in their study on PL carbonylation in 1969. Even though their conditions enabled isomerisation of PL to AA, they showed that AA could not be carbonylated to SA. Similarly, Falbe and co-workers noted during their research on acrylamide carbonylation to succinimide that AA polymerized in the presence of [Co2(CO)8] under CO atmosphere (300 bar). In a recent study, our group was the first to achieve quantitative cyclizing carbonylation of AA to SA. 12 Capitalizing on our knowledge on this reaction and on the simple system developed herein, the same systematic screening of solvents and pressures already performed for PL was applied to AA and is reported in Table . Overall, the conversions, yields, and selectivities were lower with AA than with PL. The yields and selectivities were improved in general at higher pressure, and the best result was obtained in acetone under 50 bar of CO: 65% of SA, with 78% of selectivity (Table , entry 24). SA was not detected at all when DMF was used.