Cobalt/Salox‐Catalyzed Enantioselective C−H Functionalization of Arylphosphinamides

• Published in: Angewandte Chemie International Edition Vol. 61; no. 25; pp. e202202892 - n/a
• Main Authors: Yao, Qi‐Jun, Chen, Jia‐Hao, Song, Hong, Huang, Fan‐Rui, Shi, Bing‐Feng
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 20.06.2022
• Edition: International ed. in English
• Subjects: Alcohols; Annulation; Catalysis; Cobalt; C−H Activation; Enantiomers; Enantioselectivity; Intermediates; Ligands; Molecular Structure; Salicyloxazoline; Stereoisomerism; Salicyloxazoline; Enantioselectivity; C−H Activation; Annulation; Cobalt
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202202892

Previous methods on CoIII‐catalyzed asymmetric C−H activation rely on the use of tailor‐made cyclopentadienyl‐ligated CoIII complexes, which require lengthy steps for the preparation. Herein, we report an unprecedented enantioselective C−H functionalization enabled by a simple cobalt/salicyloxazoline (Salox) catalysis. The chiral Salox ligands can be easily prepared in one step from salicylonitrile and chiral amino alcohols. A broad range of P‐stereogenic compounds were synthesized in high yields with excellent enantioselectivities (45 examples, up to 99 % yield and >99 % ee). The isolation and characterization of several intermediates provided insights into the generation of active catalytic cobalt species, the action of Salox, and the mode of stereocontrol. The enantioselective C−H annulation of arylphosphinamides with alkynes and allenes using a simple cobalt/salicyloxazoline (Salox) catalyst is reported. This new methodology provides an efficient approach for the synthesis of P‐stereogenic compounds with excellent enantioselectivities (45 examples, up to 99 % yield and >99 % ee).