Phenotellurazine redox catalysts: elements of design for radical cross-dehydrogenative coupling reactions
作者:Alina Paffen、Christopher Cremer、Frederic W Patureau
DOI:10.3762/bjoc.20.112
日期:——
Abstract Redox active phenotellurazine catalysts have been recently utilized in two different cross-dehydrogenative coupling reactions. In this study, we revisit the design of the phenotellurazine redox catalysts. In particular, we investigate the level of cooperativity between the Te- and N-centers, the effect of secondary versus tertiary N-centers, the effect of heterocyclic versus non-heterocyclic
抽象的 氧化还原活性酚碲嗪催化剂最近已用于两种不同的交叉脱氢偶联反应。在这项研究中,我们重新审视了酚碲嗪氧化还原催化剂的设计。特别是,我们研究了Te中心和N中心之间的协同水平、二级N中心与三级N中心的影响、杂环结构与非杂环结构的影响以及取代模式对氧化还原催化活性的影响。 Beilstein J. Org. Chem. 2024, 20, 1292–1297. doi:10.3762/bjoc.20.112
Remote Construction of N‐Heterocycles via 1,4‐Palladium Shift‐Mediated Double C−H Activation
作者:Takeru Miyakoshi、Nadja E. Niggli、Olivier Baudoin
DOI:10.1002/anie.202116101
日期:2022.4.19
AbstractIn the past years, Pd0‐catalyzed C(sp3)−H activation provided efficient and step‐economical methods to synthesize carbo‐ and heterocycles via direct C(sp2)−C(sp3) bond formation. We report herein that a 1,4‐Pd shift allows access to N‐heterocycles which are difficult to build via a direct reaction. It is shown thato‐bromo‐N‐methylanilines undergo a 1,4‐Pd shift at theN‐methyl group, followed by intramolecular trapping by C(sp2)−H or C(sp3)−H activation at another nitrogen substituent and remote C−C bond formation to generate biologically relevant isoindolines and β‐lactams. The product selectivity is influenced by the employed ligand, with NHCs favoring the product of remote C−C coupling against products arising from direct C−C coupling and N‐demethylation.