Polysulfide Anions as Visible Light Photoredox Catalysts for Aryl Cross-Couplings
作者:Haoyu Li、Xinxin Tang、Jia Hao Pang、Xiangyang Wu、Edwin K. L. Yeow、Jie Wu、Shunsuke Chiba
DOI:10.1021/jacs.0c11968
日期:2021.1.13
we disclose the use of polysulfide anions as visible light photoredox catalysts for aryl cross-coupling reactions. The reaction design enables single-electron reduction of aryl halides upon the photoexcitation of tetrasulfide dianions (S42-). The resulting aryl radicals are engaged in (hetero)biaryl cross-coupling, borylation, and hydrogenation in a redox catalytic regime involving S4• -/S42- and S3• -/S32-
Phosphine-Free Palladium-Catalyzed C−H Bond Arylation of Free (N−H)-Indoles and Pyrroles
作者:Xiang Wang、Denis V. Gribkov、Dalibor Sames
DOI:10.1021/jo061979v
日期:2007.2.1
This paper describes a phosphine-free palladium-catalyzed method for direct C-arylation of free (N-H)-indoles and pyrroles with iodo- and bromoarene donors. Employing commercially available materials, this new and operationally simple procedure provides a rapid entry to a wide range of C-arylated (N-H)-indoles including derivatives of tryptamine. In the course of this study, a profound halide effect was uncovered, affecting both the efficiency and regioselectivity of indole arylation.
Organophotocatalytic Arene Functionalization: C–C and C–B Bond Formation
作者:Da Seul Lee、Chung Soo Kim、Naila Iqbal、Gyeong Su Park、Kyung-sun Son、Eun Jin Cho
DOI:10.1021/acs.orglett.9b03877
日期:2019.12.20
developed in the presence of an organophotosensitizer, 3,7-di([1,1'-biphenyl]-4-yl)-10-(4-(trifluoromethyl)phenyl)-10H-phenoxazine that has highly negative reduction potential at its photoexcited state. The developed reaction conditions are mild and allow the intermolecular C-C bond formation of the generated aryl radical with electron-rich (hetero)arenes and C-B bond formation with bis(pinacolato)diboron