One pot synthesis of bioactive benzopyranones through palladium-catalyzed C–H activation and CO insertion into 2-arylphenols

Abstract

Palladium-catalyzed oxidative carbonylation of 2-arylphenols through C-H bond activation and C-C and C-O bond formation under acid-base free and mild conditions has been developed. The reaction tolerates a variety of substrates and provides biologically important benzopyranone derivatives in up to 87% isolated yield.

Synthesis of Functionalized Heterocycles via Oxidative Carbonylation

“…Later, Chuang and co-workers realized the same reaction under acid-base-free and mild conditions with Pd(OAc) 2 as the catalyst and AgOAc as oxidant (39b). Benzopyrannone derivatives were obtained in good yields [113]. As displayed in both cases, substrates with electron-donating substituents showed better activity than the electron-withdrawing ones.…”

Palladium-catalyzed oxidative dehydrogenative carbonylation reactions using carbon monoxide and mechanistic overviews

“…At the same time, the group of Chuang independently developed a similar approach with stoichiometric amounts of AgOAc as the oxidant (Scheme 12). 21 In 2011, the Lei group developed an efficient protocol for aerobic oxidative C-H carbonylation of heteroarenes for the synthesis of various heterocyclic esters in the presence of CO (Scheme 13). 22 An electrophilic palladation mechanism was proposed to explain the regioselective carbonylation reaction.…”

Transition Metal-Catalyzed Carbonylative CH Bond Functionalization of Arenes and C(sp3)H Bond of Alkanes

“…Lee et al developed a one-pot synthesis of bioactive benzopyranones by palladium-catalyzed oxidative carbonylation of 2-arylphenols through CAH bond activation and CAC and CAO bond formation under acid-base-free and mild conditions (Scheme 29). [34] Shi and coworkers reported an efficient protocol for the synthesis of dibenzopyranones through Pd-catalyzed phenoldirected CAH activation/carbonylation of 2-phenylphenol derivatives in the presence of CO (Scheme 30). [35] Various dibenzopyranone derivatives could be synthesized in the presence of Pd(OAc) 2 as a catalyst, and Cu(OAc) 2 as a catalytic oxidant, under an atmospheric pressure of CO and O 2 .…”

“…Lee et al . developed a one‐pot synthesis of bioactive benzopyranones by palladium‐catalyzed oxidative carbonylation of 2‐arylphenols through CH bond activation and CC and CO bond formation under acid‐base‐free and mild conditions (Scheme ) 34…”