One-Pot Synthesis of Xanthone by Carbonylative Suzuki Coupling Reaction

Xanthone derivatives have a dibenzo-y-pyrone scaffold which has gained great interest in Medicinal Chemistry due to their diverse biological activities. Usually, its synthesis requires multi-step synthetic routes using harsh conditions and high catalyst loadings. In this communication, we report for the first time a one-pot synthesis of the xanthone scaffold based on a carbonylative Suzuki coupling. Iodophenol and (2-methoxyphenyl)boronic acid were coupled under carbon monoxide, generated from a carbon monoxide surrogate. An experimental data-based model was built to guide the reaction optimization. The optimized conditions were 1 mol% of a pincer complex as palladium catalyst, 5 equivalents of K2CO3 as base, and DMF:water (7 : 3) as solvent. The robustness of the synthetic method, namely in terms of the reactants scope, was also evaluated. This approach provided the xanthone scaffold in high yields and provided a deep insight into the carbonylative Suzuki couplings.