Synthesis of Isothiazole via the Rhodium-Catalyzed Transannulation of 1,2,3-Thiadiazoles with Nitriles

A synthetic method for obtaining a wide variety of isothiazoles by the Rh-catalyzed transannulation of 1,2,3-thiadiazoles with alkyl, aryl, and heteroaryl nitriles, which proceeds via an α-thiavinyl Rh-carbenoid intermediate, was developed. The results suggest that during its reaction with nitriles, the α-thiavinyl carbene acts as an umpolung 1,3-dipole equivalent, in contrast to its behavior during its reaction with alkynes. The developed method was successfully employed to synthesize pentaoligomeric arylene compounds consisting of three benzene and two isothiazole rings

Synthesis of Isothiazole via the Rhodium-Catalyzed Transannulation of 1,2,3-Thiadiazoles with Nitriles

A synthetic method for obtaining a wide variety of isothiazoles by the Rh-catalyzed transannulation of 1,2,3-thiadiazoles with alkyl, aryl, and heteroaryl nitriles, which proceeds via an α-thiavinyl Rh-carbenoid intermediate, was developed. The results suggest that during its reaction with nitriles, the α-thiavinyl carbene acts as an umpolung 1,3-dipole equivalent, in contrast to its behavior during its reaction with alkynes. The developed method was successfully employed to synthesize pentaoligomeric arylene compounds consisting of three benzene and two isothiazole rings

Synthesis of Isothiazole via the Rhodium-Catalyzed Transannulation of 1,2,3-Thiadiazoles with Nitriles

A synthetic method for obtaining a wide variety of isothiazoles by the Rh-catalyzed transannulation of 1,2,3-thiadiazoles with alkyl, aryl, and heteroaryl nitriles, which proceeds via an α-thiavinyl Rh-carbenoid intermediate, was developed. The results suggest that during its reaction with nitriles, the α-thiavinyl carbene acts as an umpolung 1,3-dipole equivalent, in contrast to its behavior during its reaction with alkynes. The developed method was successfully employed to synthesize pentaoligomeric arylene compounds consisting of three benzene and two isothiazole rings

Synthesis of Isothiazole via the Rhodium-Catalyzed Transannulation of 1,2,3-Thiadiazoles with Nitriles

A synthetic method for obtaining a wide variety of isothiazoles by the Rh-catalyzed transannulation of 1,2,3-thiadiazoles with alkyl, aryl, and heteroaryl nitriles, which proceeds via an α-thiavinyl Rh-carbenoid intermediate, was developed. The results suggest that during its reaction with nitriles, the α-thiavinyl carbene acts as an umpolung 1,3-dipole equivalent, in contrast to its behavior during its reaction with alkynes. The developed method was successfully employed to synthesize pentaoligomeric arylene compounds consisting of three benzene and two isothiazole rings

Synthesis of Isothiazole via the Rhodium-Catalyzed Transannulation of 1,2,3-Thiadiazoles with Nitriles

A synthetic method for obtaining a wide variety of isothiazoles by the Rh-catalyzed transannulation of 1,2,3-thiadiazoles with alkyl, aryl, and heteroaryl nitriles, which proceeds via an α-thiavinyl Rh-carbenoid intermediate, was developed. The results suggest that during its reaction with nitriles, the α-thiavinyl carbene acts as an umpolung 1,3-dipole equivalent, in contrast to its behavior during its reaction with alkynes. The developed method was successfully employed to synthesize pentaoligomeric arylene compounds consisting of three benzene and two isothiazole rings

In Situ Generation of Phosphoryl Alkylindiums and Their Synthetic Application to Arylalkyl Phosphonates via Palladium-Catalyzed Cross-Coupling Reactions

Phosphoryl alkylindium reagents are generated in situ from the direct insertion of indium with bromoalkyl phosphonates in the presence of CuCl, and their synthetic application to arylalkyl phosphonates is reported via a Pd-catalyzed cross-coupling reaction with tolerance of a diversity of functional groups including ester, ketone, aldehyde, nitrile, nitro, trifluoromethyl, chloride, methoxy, hydroxy, and amino

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

Alkenylation of Phosphacoumarins via Aerobic Oxidative Heck Reactions and Their Synthetic Application to Fluorescent Benzo­phospha­coumarins

Alkenylation of phosphacoumarins is developed from the reaction of phosphacoumarins with a variety of activated as well as nonactivated alkenes via aerobic oxidative Heck reactions. In addition, 3-alkenyl­phospha­coumarins undergo an inverse electron demand Diels–Alder reaction (IEDDA) with enamines <i>in situ</i> generated from ketone and pyrrolidine followed by 1,2-elimination and a dehydrogenation, producing fluorescent benzo­phospha­coumarins

Synthesis of Bicyclic Isothiazoles through an Intramolecular Rhodium-Catalyzed Transannulation of Cyanothiadiazoles

An intramolecular rhodium-catalyzed transannulation of readily available cyanothiadiazoles containing an ester, amide, or ether as a linker is described. It provides a wide range of bicyclic isothiazoles in good to excellent yields together with the release of molecular nitrogen. These results indicate that the carbon atom in the α-thiavinyl carbene is nucleophilic and that the sulfur atom is electrophilic

Synthesis of Bicyclic Isothiazoles through an Intramolecular Rhodium-Catalyzed Transannulation of Cyanothiadiazoles

An intramolecular rhodium-catalyzed transannulation of readily available cyanothiadiazoles containing an ester, amide, or ether as a linker is described. It provides a wide range of bicyclic isothiazoles in good to excellent yields together with the release of molecular nitrogen. These results indicate that the carbon atom in the α-thiavinyl carbene is nucleophilic and that the sulfur atom is electrophilic