Carboxyboronate as a Versatile In Situ CO Surrogate in Palladium‐Catalyzed Carbonylative Transformations

Abstract The application of carboxy‐MIDA‐boronate (MIDA= N ‐methyliminodiacetic acid) as an in situ CO surrogate for various palladium‐catalyzed transformations is described. Carboxy‐MIDA‐boronate was previously shown to be a bench‐stable boron‐containing building block for the synthesis of borylated heterocycles. The present study demonstrates that, in addition to its utility as a precursor to heterocycle synthesis, carboxy‐MIDA‐boronate is an excellent in situ CO surrogate that is tolerant of reactive functionalities such as amines, alcohols, and carbon‐based nucleophiles. Its wide functional‐group compatibility is highlighted in the palladium‐catalyzed aminocarbonylation, alkoxycarbonylation, carbonylative Sonogashira coupling, and carbonylative Suzuki–Miyaura coupling of aryl halides. A variety of amides, esters, (hetero)aromatic ynones, and bis(hetero)aryl ketones were synthesized in good‐to‐excellent yields in a one‐pot fashion.