Rhodium‐Catalyzed Atroposelective Access to Axially Chiral Olefins via C−H Bond Activation and Directing Group Migration

Autor:	Xingwei Li, Danqing Ji, Xukai Zhou, Nan Li, Yu Lan, Haohua Chen, Fen Wang, Ruijie Mi
Rok vydání:	2021
Předmět:	chemistry.chemical_classification Steric effects Stereochemistry Migratory insertion Alkyne chemistry.chemical_element Regioselectivity General Medicine General Chemistry Catalysis Rhodium Turn (biochemistry) chemistry.chemical_compound chemistry Carboxylate
Zdroj:	Angewandte Chemie International Edition. 61
ISSN:	1521-3773 1433-7851
Popis:	Axially chiral open-chain olefins represent an underexplored class of chiral platform. In this report, two classes of tetrasubstituted axially chiral acyclic olefins have been accessed in excellent enantioselectivity and regioselectivity via C-H activation of (hetero)arenes assisted by a migratable directing group en route to coupling with sterically hindered alkynes. The coupling of indoles bearing an N-aminocarbonyl directing group afforded C-N axially chiral acrylamides with assistance of a racemic zinc carboxylate additive. DFT studies suggest a β-nitrogen elimination-reinsertion pathway for the directing group migration. Meanwhile, the employment of N-phenoxycarboxamide delivered C-C axially chiral enamides via migration of the oxidizing directing group. Experimental studies suggest that in both cases the (hetero)arene substrate adopts a well-defined orientation during the C-H activation, which in turn determines the disposition of alkyne in migratory insertion. Synthetic applications of representative chiral olefins have been demonstrated.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1e65facd023c0d5f436cd85414dad268 https://doi.org/10.1002/anie.202111860 Zobrazit plný text záznamu Plný text