C–N Axially Chiral Heterobiaryl Skeletons Construction via Cobalt-Catalyzed Atroposelective Annulation
Tong Li, Linlin Shi, Xiaofang Zhao, Jianli Wang, Xiao‐Ju Si, Dandan Yang, Mao‐Ping Song, Jun‐Long Niu
Abstract
Herein, the atroposelective construction of five-six heterobiaryl skeleton-based C-N chiral axis has been successfully accomplished via a Co-catalyzed C-H bond activation and annulation process, in which the isonitrile was employed as the C1 source and the 8-aminoquinoline moiety served as both directing group and integral part of C-N atropisomers, respectively. This conversion can be effectively carried out in an environmentally friendly oxygen atmosphere, generating the target axial heterobiaryls with excellent reactivities and enantioselectivities (up to >99% ee) in the absence of any additives, and the obtained 3-iminoisoindolinone products with a five membered N-heterocycle exhibit high atropostability. Additionally, the C-N axially chiral monophosphine backbones derived from this protocol possess the potential to become an alternative ligand platform.