Synthesis of 3,3′‐Disubstituted Isobenzofuran‐1(3H)‐Ones via Cs0.5H2.5PW12O40‐Catalyzed Difunctionalization of Carbonyls

We reported a method for the synthesis of 3,3′‐disubstituted isobenzofuran‐1(3H)‐ones via the carbonyl difunctionalization of 2‐acylbenzoic acids. A range of nucleophiles was reacted with 2‐acylbenzoic acids to furnish the functionalized isobenzofuran‐1(3H)‐ones with the factual yield range of 61–96%. The reaction uses Cs0.5H2.5PW12O40 as a catalyst and produces water as the sole by‐product. Various functional groups could be introduced to the isobenzofuran‐1(3H)‐one skeletons via the C−P/C−N/C−O/C−C bond formation, which would provide opportunities for the synthesis of potential biologically active molecules. Based on the preliminary experiments, a plausible mechanism is proposed.