Asymmetric Synthesis of β‐Lactams through Copper‐Catalyzed Alkyne–Nitrone Coupling with a Prolinol–Phosphine Chiral Ligand. Issue 35 (31st May 2017)

• Record Type: Journal Article
• Authors: Takayama, Yurie; Ishii, Takaoki; Ohmiya, Hirohisa; Iwai, Tomohiro; Schwarzer, Martin C.; Mori, Seiji; Taniguchi, Tohru; Monde, Kenji; Sawamura, Masaya
• Is Part Of: Chemistry. Volume 23:Issue 35(2017)
• Page Start: 8400
• Page End: 8404
• Publication Date: 2017-05-31
• Subjects: asymmetric catalysis -- cooperative catalysis -- copper -- nitrones -- β-lactam; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201702070
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Prolinol–phosphine chiral ligands enabled highly enantioselective copper‐catalyzed intermolecular alkyne–nitrone coupling (Kinugasa reaction) to produce 1, 3, 4‐trisubstituted chiral β‐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−H⋅⋅⋅O and C(sp 3 )−H⋅⋅⋅O hydrogen bonds is proposed. Abstract : β‐Lactam synthesis : Prolinol–phosphine chiral ligands enabled highly enantioselective copper‐catalyzed intermolecular alkyne–nitrone coupling (Kinugasa reaction) to produce 1, 3, 4‐trisubstituted chiral β‐lactams. Two‐point hydrogen bonding between the chiral ligand and the nitrone oxyanion consisting of O−H⋅⋅⋅O and C(sp 3 )−H⋅⋅⋅O hydrogen bonds is proposed.