Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Short Paper | Regular issue | Vol 98, No. 2, 2019, pp.295-303
Published online, 22nd February, 2019
DOI: 10.3987/COM-18-14022
Synthesis of 2-Substituted Indole with Hantzsch Ester Catalyzed by Palladium

Yanan Li,* Bo Wang, and Ruiguang Xing*

*School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, No.7 Arding Street, Kun District, Baotou 014010, China

Abstract

An efficient reductive cyclization of o-nitrobenzyl ketone compounds was achieved by using a Hantzsch 1,4-dihydropyridine ester as a biomimetic reducing agent in the presence of catalytic palladium on carbon. 2-Substituted indoles were obtained in good yields. Investigation of the mechanism suggests that palladium hydride promotes the reduction of nitro group, and acetic acid was beneficial for the loss of water to produce the intended product. This reaction system can not only broaden the use of Hantzsch 1,4-dihydropyridine ester, but it also provides a novel approach for preparing indole compounds.