Direct Synthesis of Pyrrolo[1,2-α]quinoxalines via Iron-Catalyzed Transfer Hydrogenation between 1-(2-Nitrophenyl)pyrroles and Alcohols

Simin Chun; Jiwon Ahn; Ramachandra Reddy Putta; Seok Beom Lee; Dong-Chan Oh; Suckchang Hong

doi:10.1021/acs.joc.0c02145

Direct Synthesis of Pyrrolo[1,2-α]quinoxalines via Iron-Catalyzed Transfer Hydrogenation between 1-(2-Nitrophenyl)pyrroles and Alcohols

J Org Chem. 2020 Dec 4;85(23):15314-15324. doi: 10.1021/acs.joc.0c02145. Epub 2020 Oct 29.

Authors

Simin Chun¹, Jiwon Ahn¹, Ramachandra Reddy Putta², Seok Beom Lee¹, Dong-Chan Oh³, Suckchang Hong¹

Affiliations

¹ Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea.
² BK 21 Plus Project, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea.
³ Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea.

PMID: 33119283
DOI: 10.1021/acs.joc.0c02145

Abstract

Herein, we describe novel iron-catalyzed transfer hydrogenation between alcohols and 1-(2-nitrophenyl)pyrroles for the synthesis of pyrrolo[1,2-α]quinoxalines. The tricarbonyl (η⁴-cyclopentadienone) iron complex catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding aldehydes and aniline were generated in situ. The resulting Pictet-Spengler-type annulation/oxidation completed the quinoxaline structure formation. The protocol tolerated various kinds of functional groups and provided 29 samples of 4-substituted pyrrolo[1,2-α]quinoxalines. The developed method was also applied for the synthesis of additional polyheterocycles.

Publication types

Research Support, Non-U.S. Gov't