Palladium- and Copper-Mediated Direct C-2 Arylation of Azoles — Including Free (NH)-Imidazole, -Benzimidazole and -Indole — Under Base-Free and Ligandless Conditions
作者:Fabio Bellina、Silvia Cauteruccio、Renzo Rossi
DOI:10.1002/ejoc.200500957
日期:2006.3
thiazole, oxazole, N-methylimidazole and N-arylimidazoles, as well as of free (NH)-imidazole, -benzimidazole and -indole, with aryliodidesunderligandless and base-freeconditions are described. Complete selectivity has been achieved under these unprecedented conditions, which allow the use of substrates containing base-sensitive groups, such the NH groups of imidazole, benzimidazole or indole, without
Regioselective Synthesis of 1,5-Diaryl-1<i>H</i>-imidazoles by Palladium-Catalyzed Direct Arylation of 1-Aryl-1<i>H</i>-imidazoles
作者:Fabio Bellina、Silvia Cauteruccio、Luisa Mannina、Renzo Rossi、Stéphane Viel
DOI:10.1021/jo050274a
日期:2005.5.1
A variety of 1,5-diaryl-1H-imidazoles have been regioselectively synthesized by direct coupling of 1-aryl-1H-imidazoles with aryl iodides or bromides in DMF in the presence of CsF as the base and a catalyst precursor consisting of a mixture of Pd(OAc)2 and AsPh3. The data obtained in this synthetic study support a reaction mechanism involving an electrophilic attack of an arylpalladium(II) halide species
Regiocontrolled Synthesis of 1,2-Diaryl-1H-imidazoles by Palladium- and Copper-Mediated Direct Coupling of 1-Aryl-1H-imidazoles with Aryl Halides under Ligandless Conditions
作者:Fabio Bellina、Silvia Cauteruccio、Luisa Mannina、Renzo Rossi、Stéphane Viel
DOI:10.1002/ejoc.200500636
日期:2006.2
involving the formation of an organocopper(I) derivatives followed by a transmetallation reaction with an arylpalladium(II) halide species and a reductive elimination, is proposed. New one-step procedures for the synthesis of 1,2,5-triaryl-1H-imidazoles, based on palladium- and copper-mediated arylation of 1-aryl-1H-imidazoles, have also been developed. Interestingly, some imidazole derivatives prepared in
Oxidative annulations via double CH bond cleavages: Approach to quinoline derivatives
作者:Zhenghui Liu、Shien Guo、Peng Wang、Zhenzhong Yan、Tiancheng Mu
DOI:10.1002/aoc.6156
日期:2021.4
system via oxidative annulations was proposed. A systematic exploration was completed. All kinds of reaction parameters were determined. And 55 kinds of target molecules were obtained with moderate to high yields. Combination of double oxidants made the conversion proceed smoothly. A clear reaction mechanism was put forward. Adjacent π systems might provide assistance for realizing the activation of relatively
Double C-H activations of C(5)-H and Csp(2)-H of 2-substituted N-vinyl- or arylimidazoles were realized without heteroatom-directing assistance by rhodium(III) catalyst. A subsequent oxidative annulation reaction with alkynes efficiently produced aza-fused heterocycles with high molecular complexity in low to excellent yields.