A nickel-catalyzed cross-electrophile coupling of benzylic sulfonium salts with aryl iodides has been developed, providing direct access to diarylalkanes from readily available and stable coupling partners. Preliminary mechanistic studies suggest that the C–S bond cleavage proceeds through a single-electron transfer process to generate a benzylic radical.
A mechanochemical synthesis of diarylethynes from aryl iodides and calcium carbide as acetylene source is reported. The reaction is catalyzed by a palladium catalyst in the presence of copper salt, base and ethanol as liquid assisting grinding (LAG) additive. Various aryl and heteroaryl iodides have been converted in up to excellent yields.
The synthesis of C-3 substituted het(aryl)indole C-nucleoside analogues bearing structurally diverse sugar moieties has been achieved by Sonogashira coupling of terminal sugar alkynes and het(aryl) iodides followed by heteroannulation of the corresponding sugar/het(aryl) alkynes with substituted 2-iodoanilines. This method is simple and general, and is suitable for structurally diverse sugars and various het(aryl) iodides. The terminal sugar alkynes include furanosides, pyranosides, and acyclic sugars with sensitive groups and bulky substituents. The het(aryl) iodides involve iodobenzene, iodothiophene, iodobenzothiophene, and iodobenzofuran. 31 examples have been given and the corresponding 2-het(aryl)indole C-nucleoside analogues are obtained in moderate to excellent yields.
An efficient Pd-catalyzed direct C−H arylation of pyrrolo[1,2-a]quinoxalines with aryl iodides has been described, offering a selective route toward a series of 1-arylated and 1,3-diarylated pyrrolo[1,2-a]quinoxalines with good yields. This...
Bu3SnH and TMS3SiH–assisted cyclizations of iodoarene derivatives of the benzo[e][1,2,4]triazine lead to the formation of planar Blatter radicals (2-phenyl-3H-[1,2,4]triazino[5,6,1-kl]phenoxazin-3-yls and 2-phenyl-3H-[1,2,4]triazino[5,6,1-kl]phenothiazin-3-yls) in yields up to 96%. The cyclization step involves...
Cu-catalyzed N-arylation is a useful tool for the chemical modification of aromatic heterocycles. Herein, an efficient carbon–nitrogen cross-coupling of methyl 3-amino-1-benzothiophene-2-carboxylate with a range of (hetero)aryl iodides using CuI, l-proline and Cs2CO3 in dioxane at moderate temperature is described. The procedure is an extremely general, relatively cheap, and experimentally simple way to afford the N-substituted products in moderate to high yields. The structures of the new heterocyclic compounds were confirmed by NMR spectroscopy and HRMS investigation.
Mild Copper-Catalyzed, l-Proline-Promoted Cross-Coupling of Methyl 3-Amino-1-benzothiophene-2-carboxylate