Assembly of 3-Substituted Isocoumarins via a CuI-Catalyzed Domino Coupling/Addition/Deacylation Process

An efficient strategy for the synthesis of a variety of 3-substituted isocoumarins has been developed. The reaction proceeded from <i>o</i>-halobenzoic acids and 1,3-diketones via a copper­(I)-catalyzed domino reaction in DMF under the action of K₃PO₄ at 90–120 °C without a ligand to afford the corresponding 3-substituted isocoumarin derivatives in good to excellent yields. <i>o</i>-Halobenzoic acids could be <i>o</i>-iodobenzoic acid, <i>o</i>-bromobenzoic acid, and <i>o</i>-chlorobenzoic acid derivatives. 1,3-Diketones could be alkyl- and aryl-substituted 1,3-diketones

Substrate-Controlled Transformation of Azobenzenes to Indazoles and Indoles via Rh(III)-Catalysis

Rh­(III)-catalyzed substrate-controlled transformation of azobenzenes to indazoles and 2-acyl (NH) indoles is achieved via C–H functionalization. Generally, good functional groups tolerance, satisfying yields, and excellent regio-selectivity are achieved in this reaction. Mechanistically, the reaction with acrylates undergoes β-hydride elimination, while the reaction with vinyl ketones or acrylamides undergoes nucleophilic addition. Copper acetate was supposed to play different roles in the β-hydride elimination to furnish indazoles and nucleophilic addition of C–Rh bond to deliver 2-acyl (NH) indoles

Substrate-Controlled Transformation of Azobenzenes to Indazoles and Indoles via Rh(III)-Catalysis

Rh­(III)-catalyzed substrate-controlled transformation of azobenzenes to indazoles and 2-acyl (NH) indoles is achieved via C–H functionalization. Generally, good functional groups tolerance, satisfying yields, and excellent regio-selectivity are achieved in this reaction. Mechanistically, the reaction with acrylates undergoes β-hydride elimination, while the reaction with vinyl ketones or acrylamides undergoes nucleophilic addition. Copper acetate was supposed to play different roles in the β-hydride elimination to furnish indazoles and nucleophilic addition of C–Rh bond to deliver 2-acyl (NH) indoles

Rh(III)-Catalyzed Cascade Oxidative Olefination/Cyclization of Picolinamides and Alkenes via C–H Activation

Rh­(III)-catalyzed cascade oxidative alkenylation/cyclization of picolinamides and alkenes to furnish pyrido pyrrolone derivatives is described, in which three C–H bonds and one N–H bond broke, while one C–C bond and one C–N bond formed. The reaction proceeded with high yield and high regioselectivity and stereoselectivity. Moreover, copper acetate can also be used in catalytic amounts with O₂ serving as the terminal oxidant

Rh(III)-Catalyzed Cascade Oxidative Olefination/Cyclization of Picolinamides and Alkenes via C–H Activation

Rh­(III)-catalyzed cascade oxidative alkenylation/cyclization of picolinamides and alkenes to furnish pyrido pyrrolone derivatives is described, in which three C–H bonds and one N–H bond broke, while one C–C bond and one C–N bond formed. The reaction proceeded with high yield and high regioselectivity and stereoselectivity. Moreover, copper acetate can also be used in catalytic amounts with O₂ serving as the terminal oxidant