Cobalt-Catalyzed Carbonylative Cyclization of Pyridinyl Diazoacetates for the Synthesis of Pyridoisoquinolinones

Dicobalt octacarbonyl-catalyzed carbonylative cyclization of pyridinyl diazoacetates is developed for the synthesis of pyridoisoquinolinones under mild conditions (room temperature) in a carbon monoxide atmosphere. Moreover, a synthetic method for various pyridoisoquinolinones from ethylpyridinyl aryl acetates is demonstrated through diazotization using TsN₃ and DBU followed by Co-catalyzed carbonylation to generate ketene intermediates, which can subsequently undergo intramolecular cyclization under mild conditions in a carbon monoxide atmosphere in a semi-one-pot fashion

Synthesis of Cinnolin-3(2<i>H</i>)‑one Derivatives from Rh-Catalyzed Reaction of Azobenzenes with Diazotized Meldrum’s Acid

A synthetic method of a wide range of cinnolin-3­(2<i>H</i>)-one derivatives is developed from the reaction of symmetrical as well as unsymmetrical azobenzenes with diazotized Meldrum’s acid <i>via</i> Rh-catalyzed C–H alkylation followed by cyclization

Synthesis of Fluorenes via Tandem Copper-Catalyzed [3 + 2] Cycloaddition and Rhodium-Catalyzed Denitrogenative Cyclization in a 5-<i>Exo</i> Mode from 2‑Ethynylbiaryls and <i>N</i>‑Sulfonyl Azides in One Pot

An efficient synthetic method of fluorenes having an enamine moiety at C-9 methylene bridge is developed from <i>N</i>-sulfonyl-4-biaryl-1,2,3-triazole derivatives via Rh-catalyzed denitrogenative cyclization in a 5-<i>exo</i> mode. Rh-catalyzed denitrogenative cyclization followed by catalytic hydrogenation produces <i>N</i>-tosylaminomethyl-substituted fluorenes in one pot. Moreover, fluorenes are synthesized via tandem Cu-catalyzed [3 + 2] cycloaddition and Rh-catalyzed denitrogenative cyclization in a 5-<i>exo</i> mode starting from 2-ethynylbiaryls and <i>N</i>-sulfonyl azides in one pot

Synthesis of Cinnolin-3(2<i>H</i>)‑one Derivatives from Rh-Catalyzed Reaction of Azobenzenes with Diazotized Meldrum’s Acid

A synthetic method of a wide range of cinnolin-3­(2<i>H</i>)-one derivatives is developed from the reaction of symmetrical as well as unsymmetrical azobenzenes with diazotized Meldrum’s acid <i>via</i> Rh-catalyzed C–H alkylation followed by cyclization

Synthesis of Cinnolin-3(2<i>H</i>)‑one Derivatives from Rh-Catalyzed Reaction of Azobenzenes with Diazotized Meldrum’s Acid

A synthetic method of a wide range of cinnolin-3­(2<i>H</i>)-one derivatives is developed from the reaction of symmetrical as well as unsymmetrical azobenzenes with diazotized Meldrum’s acid <i>via</i> Rh-catalyzed C–H alkylation followed by cyclization