Palladium Catalyzed Carbonylative Coupling for Synthesis of Arylketones and Arylesters Using Chloroform as the Carbon Monoxide Source

We describe a modular,
palladium catalyzed synthesis of aryl­(hetero)­aryl
benzophenones and aryl benzoates from aryl­(hetero)­aryl halides using
CHCl3 as the carbonyl source in the presence of KOH. The
reaction occurs in tandem through an initial carbonylation to generate
an aroyl halide, which undergoes coupling with arylboronic acids,
bornonates, and phenols. Direct carbonylative coupling of indoles
at the third position has also been accomplished under slightly modified
reaction conditions by in situ activation of the
C–H bond. Notably, CHCl3 is a convenient and safe
alternation of CO gas, provides milder reaction conditions with high
functional group tolerance, and gives the products in moderate to
good yields.