Efficient Approach to 4‑Sulfonamidoquinolines via Copper(I)-Catalyzed Cascade Reaction of Sulfonyl Azides with Alkynyl Imines

A novel and efficient approach to 4-sulfonamidoquinolines via copper-catalyzed cascade reaction of sulfonyl azides with alkynyl imines has been developed in which a 1,3-dipole cycloaddition/ketenimine formation/6π-electrocyclization/[1,3]-H shift cascade reaction was involved. Various 4-sulfonamidoquinolines were afforded in up to 84% yield for 19 examples. This synthetic strategy features with atom economy, concise steps, easy operation, and mild reaction conditions

Iridium-Catalyzed Direct C–H Sulfamidation of Aryl Nitrones with Sulfonyl Azides at Room Temperature

Ir­(III)-catalyzed direct C–H sulfamidation of aryl nitrones has been developed to synthesize various sulfamidated nitrones in moderate to excellent yields with excellent regioselectivity and broad functional group tolerance. This transformation could proceed smoothly at room temperature with low catalyst loading in the absence of external oxidants, acids, or bases. Molecular nitrogen was released as the sole byproduct, thus providing an environmentally benign sulfamidation process. And this protocol could efficiently apply to synthesize the substituted benzisoxazoline via one-step transformation from the product

C8-Selective Acylation of Quinoline <i>N</i>‑Oxides with α‑Oxocarboxylic Acids via Palladium-Catalyzed Regioselective C–H Bond Activation

A facile and efficient protocol for palladium-catalyzed C8-selective acylation of quinoline <i>N</i>-oxides with α-oxocarboxylic acids has been developed. In this approach, <i>N</i>-oxide was utilized as a stepping stone for the remote C–H functionalization. The reactions proceeded efficiently under mild reaction conditions with excellent regioselectivity and broad functional group tolerance

“One-Pot” Approach to 8‑Acylated 2‑Quinolinones via Palladium-Catalyzed Regioselective Acylation of Quinoline <i>N</i>‑Oxides

A “one-pot” facile and efficient protocol for 8-acylated 2-quinolinones has been developed through palladium-catalyzed acylation of quinoline <i>N</i>-oxides, which proceeds with high selectivity at the C8-position. The desired products were isolated in up to 95% yield and good functional group tolerance. A palladacycle was isolated from the catalytic process and proposed as a key intermediate

“One-Pot” Approach to 8‑Acylated 2‑Quinolinones via Palladium-Catalyzed Regioselective Acylation of Quinoline <i>N</i>‑Oxides

A “one-pot” facile and efficient protocol for 8-acylated 2-quinolinones has been developed through palladium-catalyzed acylation of quinoline <i>N</i>-oxides, which proceeds with high selectivity at the C8-position. The desired products were isolated in up to 95% yield and good functional group tolerance. A palladacycle was isolated from the catalytic process and proposed as a key intermediate

Rhodium(III)-Catalyzed C–H Activation/Alkyne Annulation by Weak Coordination of Peresters with O–O Bond as an Internal Oxidant

A redox-economic strategy has been developed, involved in an efficient Rh­(III)-catalyzed oxidative C–H activation and alkyne annulation with perester as the oxidizing directing group. In this process, the cleavage of an oxidizing O–O bond as an internal oxidant is described for the first time. This reaction could be carried out under mild conditions and exhibits excellent regioselectivity and wide functional groups tolerance

Iridium-Catalyzed Direct C–H Sulfamidation of Aryl Nitrones with Sulfonyl Azides at Room Temperature

Ir­(III)-catalyzed direct C–H sulfamidation of aryl nitrones has been developed to synthesize various sulfamidated nitrones in moderate to excellent yields with excellent regioselectivity and broad functional group tolerance. This transformation could proceed smoothly at room temperature with low catalyst loading in the absence of external oxidants, acids, or bases. Molecular nitrogen was released as the sole byproduct, thus providing an environmentally benign sulfamidation process. And this protocol could efficiently apply to synthesize the substituted benzisoxazoline via one-step transformation from the product

“One-Pot” Approach to 8‑Acylated 2‑Quinolinones via Palladium-Catalyzed Regioselective Acylation of Quinoline <i>N</i>‑Oxides

A “one-pot” facile and efficient protocol for 8-acylated 2-quinolinones has been developed through palladium-catalyzed acylation of quinoline <i>N</i>-oxides, which proceeds with high selectivity at the C8-position. The desired products were isolated in up to 95% yield and good functional group tolerance. A palladacycle was isolated from the catalytic process and proposed as a key intermediate

“One-Pot” Approach to 8‑Acylated 2‑Quinolinones via Palladium-Catalyzed Regioselective Acylation of Quinoline <i>N</i>‑Oxides

A “one-pot” facile and efficient protocol for 8-acylated 2-quinolinones has been developed through palladium-catalyzed acylation of quinoline <i>N</i>-oxides, which proceeds with high selectivity at the C8-position. The desired products were isolated in up to 95% yield and good functional group tolerance. A palladacycle was isolated from the catalytic process and proposed as a key intermediate

Base-Promoted N‑Pyridylation of Heteroarenes Using <i>N</i>‑Propargyl Enaminones as Equivalents of Pyridine Scaffolds

N-Pyridylation of various N-heteroarenes, including N-heteroarene-containing peptides, was achieved using <i>N</i>-propargyl enaminones (isolated or generated in situ from propargyl amine and propynones) as masked polysubstituted pyridine cores. This metal-free procedure proceeds under mild reaction conditions and generates 1 equiv of H₂O as the sole byproduct