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Asymmetric Synthesis of β‐Lactams through Copper‐Catalyzed Alkyne–Nitrone Coupling with a Prolinol–Phosphine Chiral Ligand
Author(s) -
Takayama Yurie,
Ishii Takaoki,
Ohmiya Hirohisa,
Iwai Tomohiro,
Schwarzer Martin C.,
Mori Seiji,
Taniguchi Tohru,
Monde Kenji,
Sawamura Masaya
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201702070
Subject(s) - nitrone , alkyne , phosphine , enantioselective synthesis , ligand (biochemistry) , chemistry , chiral ligand , catalysis , aryl , coupling reaction , stereochemistry , combinatorial chemistry , medicinal chemistry , organic chemistry , cycloaddition , biochemistry , alkyl , receptor
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.