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Cu-mediated enantioselective C–H alkynylation of ferrocenes with chiral BINOL ligands

A wide range of Cu(II)-catalyzed C–H activation reactions have been realized since 2006, however, whether a C–H metalation mechanism similar to Pd(II)-catalyzed C–H activation reaction is operating remains an open question. To address this question and ultimately develop ligand accelerated Cu(II)-ca...

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Detalles Bibliográficos
Autores principales: Kuang, Xin, Li, Jian-Jun, Liu, Tao, Ding, Chang-Hua, Wu, Kevin, Wang, Peng, Yu, Jin-Quan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10673954/
https://www.ncbi.nlm.nih.gov/pubmed/38001060
http://dx.doi.org/10.1038/s41467-023-43278-z
Descripción
Sumario:A wide range of Cu(II)-catalyzed C–H activation reactions have been realized since 2006, however, whether a C–H metalation mechanism similar to Pd(II)-catalyzed C–H activation reaction is operating remains an open question. To address this question and ultimately develop ligand accelerated Cu(II)-catalyzed C–H activation reactions, realizing the enantioselective version and investigating the mechanism is critically important. With a modified chiral BINOL ligand, we report the first example of Cu-mediated enantioselective C–H activation reaction for the construction of planar chiral ferrocenes with high yields and stereoinduction. The key to the success of this reaction is the discovery of a ligand acceleration effect with the BINOL-based diol ligand in the directed Cu-catalyzed C–H alkynylation of ferrocene derivatives bearing an oxazoline-aniline directing group. This transformation is compatible with terminal aryl and alkyl alkynes, which are incompatible with Pd-catalyzed C–H activation reactions. This finding provides an invaluable mechanistic information in determining whether Cu(II) cleaves C–H bonds via CMD pathway in analogous manner to Pd(II) catalysts.