Development of Novel <scp>Phosphino‐Oxazoline</scp> Ligands and Their Application in Asymmetric Alkynlylation of Benzylic Halides
Rui Guo, Jiale Sang, Haijing Xiao, Jun‐Xia Li, Guozhu Zhang
Abstract
Comprehensive Summary A new set of stereochemically diverse phosphino‐oxazoline ligands derived from simple L ‐amino acids and 2‐(diphenylphosphaneyl)benzoic acid were developed. Those mono anionic tridentated N,N,P‐ligands promote the Cu‐catalyzed enantioselective radical coupling of terminal alkynes with a broad range of benzylic halides including benzo‐fused cyclic α‐halides and α‐silyl benzyl halides in high yield and excellent enantioselectivity under mild reaction conditions. With multi distinct sites for structural modification, a diverse pool of chiral N,N,P‐ligands is readily accessed, allowing for rapid optimization of the ligand structure for a specific substrate. Notably, the enantioselective alkynlylation of benzylic halides bonds in benzo‐cyclic molecules has also been realized for the first time.