Palladium‐Catalyzed Synthesis of Carboxylic Acid Anhydrides from Alkenes via in situ Generated Carboxylic Acids

We herein present a carbonylative strategy to synthesize carboxylic acid anhydrides from alkenes from in situ generated carboxylic acids. Formic acid (FA) reacts with alkene and CO under catalytic conditions to generate carboxylic acids. With our established palladium‐based catalytic reaction conditions and modulating the alkene:formic acid ratio to at least 2 : 1, acid anhydrides were effectively generated from alkenes. The catalytic process was applied to various alkenes, simple as well as with various functional groups, to give moderate to excellent yields as observed with NMR and upon isolation of the corresponding (linear) amide produced on derivatization. Furthermore, one‐pot derivatization of the reaction mixtures provides direct access to various acyl‐based molecules including phenolic esters, primary amides, thioesters and ketones, which otherwise require special conditions for their synthesis via carbonylation. A carbonylative synthetic methodology is described to form carboxylic acid anhydrides from alkenes with in situ generated carboxylic acids. Using formic acid as nucleophile, carboxylic acids are readily accessible, and which can act further as nucleophiles in a tandem carbonylation cycle to generate carboxylic acid anhydrides. In a subsequent derivatization reaction, these anhydrides can be directly converted to amides, (thio−)esters and ketones.