Copper-Catalyzed Divergent Addition Reactions of Enoldiazoacetamides with Nitrones

Catalyst-controlled divergent addition reactions of enol­diazo­acetamides with nitrones have been developed. By using copper­(I) tetrafluoroborate/bisoxazoline complex as the catalyst, a [3+3]-cycloaddition reaction was achieved with excellent yield and enantioselectivity under exceptionally mild conditions, which represents the first highly enantioselective base-metal-catalyzed vinylcarbene transformation. When the catalyst was changed to copper­(I) triflate, Mannich addition products were formed in high yields with near exclusivity under otherwise identical conditions

Transition-Metal-Catalyzed Arylation of Nitroimidazoles and Further Transformations of Manipulable Nitro Group

Pd- or Ni-catalyzed C–H arylation of 4-nitroimidazole derivatives directed by a manipulable nitro group was developed. The reaction tolerates a wide range of substituted aryl halides and 4-nitroimidazoles. The experiments indicated that the nitro group has influence on regioselectivity of the reaction. In addition, we have shown that the efficiency of the Suzuki–Miyaura cross-coupling reaction of nitroimidazoles is slightly lower in comparison to the direct C–H arylation. The exploration of the chemical potential of the nitro group and a putative reaction mechanism are discussed