Development of Novel Phosphino‐Oxazoline Ligands and Their Application in Asymmetric Alkynlylation of Benzylic Halides

Abstract

Comprehensive SummaryA 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.