Issue 2, 2018

Metal-free tandem cyclization/hydrosilylation to construct tetrahydroquinoxalines

Abstract

A one-pot tandem procedure involving cyclization and sequential hydrosilylation of imines and amides under the catalysis of B(C6F5)3 has been developed for the step-economical construction of 1,2,3,4-tetrahydroquinoxalines directly from readily available 1,2-diaminobenzenes, α-ketoesters and low-cost, safe polymethylhydrosiloxane (PMHS). This metal-free approach provides various products in good to excellent yields, and displays a wide range of substrate scope and a high degree of functional group tolerance even to reduction-sensitive moieties. The choice of hydrosilanes is critical to the catalysis, and PMHS has proved to be optimal. Decreasing the amount of PMHS could enable the reaction to stop at the 3,4-dihydroquinoxalin-2(1H)-one stage. The procedure is convenient and scalable, and neither a dried solvent nor an inert atmosphere is required. Moreover, the enantioselective construction of these products was explored, and promising results were achieved.

Graphical abstract: Metal-free tandem cyclization/hydrosilylation to construct tetrahydroquinoxalines

Supplementary files

Article information

Article type
Paper
Submitted
14 okt 2017
Accepted
02 noy 2017
First published
03 noy 2017

Green Chem., 2018,20, 403-411

Metal-free tandem cyclization/hydrosilylation to construct tetrahydroquinoxalines

Y. Pan, C. Chen, X. Xu, H. Zhao, J. Han, H. Li, L. Xu, Q. Fan and J. Xiao, Green Chem., 2018, 20, 403 DOI: 10.1039/C7GC03095A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements