Direct C-H Arylation of Heteroarenes with Aryl Chlorides by Using an Abnormal N-Heterocyclic-Carbene-Palladium Catalyst
作者:Jasimuddin Ahmed、Samaresh Chandra Sau、Sreejyothi P、Pradip Kumar Hota、Pavan K. Vardhanapu、Gonela Vijaykumar、Swadhin K. Mandal
DOI:10.1002/ejoc.201601218
日期:2017.2.3
Herein, we report a versatilecatalyticsystem for the direct C–H arylation of heteroarenes with activated arylchloride substrates. The catalyst works successfully for a variety of heteroarenes and arylchloride coupling partners under very low catalyst-loading conditions. We have successfully performed the direct C–H arylations of 1-methylpyrrole, 1-methylindole, furan, thiophene, furfural, and N-benzyl-1
A Cu/Pd-catalyzed, three-component click reaction of azide, alkyne, and aryl halide has been developed. By using this Cu/Pd transmetalation relay catalysis, a variety of 1,4,5-trisubstituted 1,2,3-triazoles were quickly assembled in one step in high yields with complete regioselectivity, just like assembling Lego bricks. Notably, different from the well-established CuAAC click reactions only working on terminal alkynes, this reaction offers an alternative solution for the problem of the click reaction of internal alkynes.
Developing Bis(imino)acenaphthene-Supported <i>N</i>-Heterocyclic Carbene Palladium Precatalysts for Direct Arylation of Azoles
作者:Li-Qun Hu、Rong-Li Deng、Yan-Fen Li、Cui-Jin Zeng、Dong-Sheng Shen、Feng-Shou Liu
DOI:10.1021/acs.organomet.7b00784
日期:2018.1.22
On the basis of the strategy of developing highly efficient protocol for Pd-catalyzed cross-coupling reactions, a series of bulky bis(imino)acenaphthene (BIAN)-supported Pd-PEPPSI complexes were synthesized, characterized, and applied in direct arylation of azoles. The effect of backbone and N-moieties on NHCs was evaluated, and the reaction conditions were optimized. It was found that the bulky Pd-PEPPSI complexes could be successfully employed in cross-coupling of (hetero)aryl bromides with azoles at a low palladium loading of 0.5-0.05 mol % under aerobic conditions, demonstrating the ease of manipulation without glovebox and handling of solvents.