The selectivity of the carbonylation of PL to SA is then quite sensitive to the temperature. Interestingly, increasing the CO pressure prevented this selectivity drop: 95% of SA was afforded at 130 °C, after 3 h under 50 bar of CO (Table , entry 8). The latter result indicates the interdependency between pressure and temperature. Finally, some catalytic activity was observed at temperatures as low as 70 °C and 50 °C (82% yield of SA after 65 h and 51% yield of SA after 65 h, respectively. See S.I. for details). A lower catalyst loading slows down the reaction, but maintains the selectivity towards succinic anhydride (Figure ). 92% of SA was obtained after 16 h with 2.5 mol% of [Co2(CO)8], and 60% after 72 h with 1 mol%, with a high selectivity (for each experiment, selectivity >87%).