1.
Chemistry
; 23(35): 8400-8404, 2017 Jun 22.
Artículo
en Inglés
| MEDLINE
| ID: mdl-28488338
RESUMEN
Prolinol-phosphine chiral ligands enabled highly enantioselective copper-catalyzed intermolecular alkyne-nitrone coupling (Kinugasa reaction) to produce 1,3,4-trisubstituted chiral ß-lactams. A high level of enantiocontrol was achieved not only with aryl- or alkenylacetylenes but also with alkylacetylenes, which were important but unfavorable substrates in the previously reported protocols. Two-point hydrogen bonding between the chiral ligand and the nitrone oxyanion consisting of O-Hâ â â O and C(sp3 )-Hâ â â O hydrogen bonds is proposed.