Enantioselective Cascade Reaction for Synthesis of Quinolinones through Synergistic Catalysis Using Cu-Pybox and Chiral Benzotetramisole as Catalysts

Xuehe Lu; Luo Ge; Cang Cheng; Jie Chen; Weiguo Cao; Xiaoyu Wu

doi:10.1002/chem.201701741

Enantioselective Cascade Reaction for Synthesis of Quinolinones through Synergistic Catalysis Using Cu-Pybox and Chiral Benzotetramisole as Catalysts

Chemistry. 2017 Jun 7;23(32):7689-7693. doi: 10.1002/chem.201701741. Epub 2017 May 15.

Authors

Xuehe Lu¹, Luo Ge¹, Cang Cheng¹, Jie Chen¹, Weiguo Cao¹, Xiaoyu Wu^{1

2}

Affiliations

¹ Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Lu, Shanghai, 200444, P. R. China.
² Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, P. R. China.

PMID: 28425212
DOI: 10.1002/chem.201701741

Abstract

In contrast to the well-studied asymmetric catalyzed synthesis of tetrahydroquinolines, the asymmetric methodologies toward 3,4-dihydroquinolin-2-ones are quite rare. Herein, the first asymmetric cascade reaction is reported between ethynyl benzoxazinanones and mixed-anhydrides generated from aryl acetic acids and pivaloyl chloride, based on synergistic catalysis. This allowed the formation of attractive 3,4-dihydroquinolin-2-ones bearing two vicinal chiral centers at C3 and C4 in high yields with excellent diastereo- and enantioselectivities. A plausible chiral induction model for this reaction was proposed. The utility of this methodology was exemplified by further elaboration of the cyclization products by removal of the N-protecting groups.

Keywords: Lewis base; copper; cyclization; quinolinones; synergistic catalysis.