Cobalt-Catalyzed Domino Transformations via Enantioselective C–H Activation/Nucleophilic [3 + 2] Annulation toward Chiral Bridged Bicycles
Fan‐Rui Huang, Qi‐Jun Yao, Peng Zhang, Ming‐Ya Teng, Jiahao Chen, Lu-Chen Jiang, Bing‐Feng Shi
Abstract
Selective synthesis of chiral bridged (hetero)bicyclic scaffolds via asymmetric C-H activation constitutes substantial challenges due to the multiple reactivities of strained bicyclic structures. Herein, we develop the domino transformations through an unprecedented cobalt-catalyzed enantioselective C-H activation/nucleophilic [3 + 2] annulation with symmetrical bicyclic alkenes. The methods offer straightforward access to a wide range of chiral molecules bearing [2.2.1]-bridged bicyclic cores with four and five consecutive stereocenters in a single step. Two elaborate salicyloxazoline (Salox) ligands were synthesized based on the rational design and mechanistic understanding. The well-defined chiral pockets generated from asymmetric coordination around the trivalent cobalt catalyst direct the orientation of bicyclic alkenes, leading to excellent enantioselectivity.