A Highly cis‐Selective and Enantioselective Metal‐Free Hydrogenation of 2, 3‐Disubstituted Quinoxalines1. Issue 2 (13th November 2014)

• Record Type: Journal Article
• Authors: Zhang, Zhenhua; Du, Haifeng
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 2(2015)
• Page Start: 623
• Page End: 626
• Publication Date: 2014-11-13
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201409471
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A wide range of 2, 3‐disubstituted quinoxalines have been successfully hydrogenated with H₂ using borane catalysts to produce the desired tetrahydroquinoxalines in 80–99 % yields with excellent <italic>cis</italic> selectivity. Significantly, the asymmetric reaction employing chiral borane catalysts generated by the in situ hydroboration of chiral dienes with HB(C₆F₅)₂ under mild reaction conditions has also been achieved with up to 96 % <italic>ee</italic>, and represents the first catalytic asymmetric system to furnish optically active <italic>cis</italic>‐2, 3‐disubstituted 1, 2, 3, 4‐tetrahydroquinoxalines.</p> </abstract>