Base-promoted, CBr4-mediated tandem bromination/intramolecular Friedel–Crafts alkylation of N-aryl enamines: a facile access to 1H- and 3H-indoles. Issue 24 (28th May 2021)

• Record Type: Journal Article
• Authors: Zhao, Lan; Qiu, Changfu; Zhao, Lixin; Yin, Guangwei; Li, Fangyi; Wang, Chunhua; Li, Zheng
• Is Part Of: Organic & biomolecular chemistry. Volume 19:Issue 24(2021)
• Page Start: 5377
• Page End: 5382
• Publication Date: 2021-05-28
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d1ob00731a
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : In the presence of CBr4 and a suitable base, the cyclization reaction of N -aryl enamines proceeds with high efficiency leading to a series of 1 H -indoles and 3 H -indoles with moderate to good yields. Abstract : Described here is a general and highly efficient method for the synthesis of 1 H - and 3 H -indoles. In the presence of CBr4 and a suitable base, the cyclization of N -aryl enamines proceeds with high efficiency. Unlike previous intramolecular cross dehydrogenative coupling (CDC) of the same substrates, this process does not require the use of either a transition metal or a stoichiometric amount of oxidant. This method also features operational simplicity, easy scalability and good substrate tolerability. Control experiments indicate the reactions may proceed in a tandem sequence of bromination and intramolecular Friedel–Crafts alkylation in a simple one-pot procedure.