RESUMO
A new strategy for the synthesis of amides has been developed using sulfur-mediated decarboxylative coupling of cinnamic acids with amines via oxidative cleavage of the CâC bond.
RESUMO
A practical synthesis of new ß-difluoromethoxy vinyl sulfones has been explored by O-difluoromethylation of ß-ketosulfones using the inexpensive and easily workable sodium chlorodifluoroacetate as a difluorocarbene precursor. The strategy is convenient and regioselective, and features an adequate substrate scope and functional group tolerance.
RESUMO
Herein, we have developed the cyclic diaryliodonium salts as biarylating agents in the C(sp3)-H functionalization using 8-methyl quinoline as the intrinsic directing group. The oxidant-free reaction produces a vast array of the biarylated products with iodo functionality that can be further functionalized. Additionally, intramolecular C(sp3)-H functionalization in a stepwise manner under palladium-catalyzed conditions produced the fluorene derivatives in excellent yields.
Assuntos
Paládio , Quinolinas , Sais , Catálise , FluorenosRESUMO
A domino reaction sequence of cyclopropanation/ring-opening/iminium cyclization of tryptamine derivatives with donor-acceptor diazo compounds is developed to furnish pyrroloindolines, creating three consecutive stereogenic centers in a single step. The copper-catalyzed reaction provides pyrroloindolines at room-temperature with good substrate scope.
Assuntos
Cobre , Indóis , Cobre/química , Indóis/química , Estereoisomerismo , Triptaminas/química , Compostos Azo , CatáliseRESUMO
A mild, palladium-catalyzed domino Heck-cyclization/alkoxylation sequence of aryl halide tethered allenamides is described, providing regiodivergent indole and indoline derivatives controlled by the N-protecting group. This room temperature reaction provided a functionalizable olefinic moiety with broad substrate scope. Preliminary mechanistic studies support the rearrangement of an indoline-derived intermediate to indoles with the N-acetyl allenamides forming free (NH) indoles.
Assuntos
Indóis , Paládio , Catálise , Ciclização , Estrutura MolecularRESUMO
Catalytic transfer hydrogenation (TH) for the reduction of heterocycles is an emerging strategy for accessing biologically active saturated N-heterocycles. Herein, we report a TH protocol that utilizes ethanol as a renewable hydrogen source and an Ir catalyst for the reduction of quinolines and pyridines. The reaction is promoted by simple amides as ligands.
Assuntos
Etanol , Hidrogênio , Catálise , Hidrogenação , PiridinasRESUMO
A palladium-catalyzed domino Heck/intermolecular direct hetero arylation sequence of unactivated alkenes was developed, providing 1,2,3-triazole containing bisheterocycles bearing all-carbon quaternary centers with yields of 25-90%. The protocol was extended to 1,3,4-oxadiazoles as well. The installed triazole was further exploited for late-stage functionalizations, and the mechanistic studies indicate the involvement of C-H activation.