Chiral zinc amidate catalyzed additions of diethylzinc to aldehydes. Issue 29 (18th July 2019)

• Record Type: Journal Article
• Authors: Zhang, Jinxia; Li, Shasha; Zheng, Xinxin; Li, Hongjie; Jiao, Peng
• Is Part Of: Tetrahedron letters. Volume 60:Issue 29(2019)
• Page Start: 1913
• Page End: 1917
• Publication Date: 2019-07-18
• Subjects: Asymmetric addition -- Diethylzinc -- Chiral amidate -- Spiro ligand; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2019.06.031
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Chiral zinc amidate catalyzes additions of Et2 Zn to aldehydes in high yields and mediocre ee. Carboxamides bearing a phosphine oxide group work as bifunctional ligands. Spiro[indane-1, 2′-pyrrolidin]-5′-one constitutes a rigid backbone for effective chiral ligands. Abstract: A series of bifunctional spiro ligands bearing "carboxamide–phosphine oxide" groups and ethylzinc carboxamidates from these ligands as catalysts for Et2 Zn additions to aldehydes were reported. Excellent yields were obtained with moderate ee′s in Et2 Zn additions to benzaldehyde derivatives, implying effectiveness of our newly designed catalytic structures as well as mediocre stereocontrol by these chiral ligands. Possible transition states were suggested based on the crystal structures of two ligands.