Visible-Light-Induced Amination of Quinoline at the C8 Position via a Postcoordinated Interligand-Coupling Strategy under Mild Conditions

The postcoordinated interligand-coupling strategy provides a useful and complementary protocol for synthesizing polydentate ligands. Herein, diastereoselective photoreactions of Λ-[Ir­(pq)2(d-AA)] (Λ-d ) and Λ-[Ir­(pq)2(l-AA)] (Λ-l , where pq is 2-phenylquinoline and AA is an amino acid) are reporte...

Full description

Saved in:
Bibliographic Details
Published in:Inorganic chemistry 2021-01, Vol.60 (2), p.908-918
Main Authors: Peng, He-Long, Li, Yinwu, Chen, Xing-Yang, Li, Li-Ping, Ke, Zhuofeng, Ye, Bao-Hui
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The postcoordinated interligand-coupling strategy provides a useful and complementary protocol for synthesizing polydentate ligands. Herein, diastereoselective photoreactions of Λ-[Ir­(pq)2(d-AA)] (Λ-d ) and Λ-[Ir­(pq)2(l-AA)] (Λ-l , where pq is 2-phenylquinoline and AA is an amino acid) are reported in the presence of O2 under mild conditions. Diastereomer Λ-d is dehydrogenatively oxidized into an imino acid complex, while diastereomer Λ-l mainly occurs via interligand C–N cross-dehydrogenative coupling between quinoline at the C8 position and AA ligands at room temperature, affording Λ-[Ir­(pq)­(l-pq-AA)]. Furthermore, the photoreaction of diastereomer Λ-l is temperature-dependent. Mechanistic experiments reveal the ligand–radical intermediates may be involved in the reaction. Density functional theory calculations were used to eluciate the origin of diastereoselectivity and temperature dependence. This will provide a new protocol for the amination of quinoline at the C8 position via the postcoordinated interligand C–N cross-coupling strategy under mild conditions.
ISSN:0020-1669
1520-510X
DOI:10.1021/acs.inorgchem.0c03026