TBAI-assisted direct C–H activation of indoles with β-E-styrene sulfonyl hydrazides: a stereoselective access to 3-styryl thioindoles. Issue 26 (27th April 2021)

• Record Type: Journal Article
• Authors: Hafeez, Saira; Saeed, Aamer
• Is Part Of: RSC advances. Volume 11:Issue 26(2021)
• Page Start: 15608
• Page End: 15616
• Publication Date: 2021-04-27
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1ra02444b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Direct C–H activation of indoles with beta-( E )-styrene sulfonyl hydrazides assisted by TBAI afforded structurally diverse indole vinyl thioethers in moderate to high yields with E -stereoselectivity. Abstract : The current work describes the challenging introduction of a vinyl sulfide group by simple C–H activation on a variety of substrates. The direct C–H activation of indoles with β-( E )-styrene sulfonyl hydrazides under the sulfenylation conditions, assisted by the iodic catalyst tert -butyl ammonium iodide (TBAI), afforded a series of ( E )-styrylthioindoles. Accordingly, β-( E )-styrene sulfonyl hydrazides undergo radical cross-coupling reactions with a variety of substituted indoles to afford structurally diverse indole vinyl thioethers in moderate to high yields with E -stereoselectivity. This method is metal-catalyst-free and is valuable not only because of its novelty, but also for providing a convenient synthetic pathway to a variety of ( E )-styrylthioindoles with retention of the configuration. The current study paves the way for the use of β-( E )-styrene sulfonyl hydrazides as a unique styryl mercaptan source in chemical synthesis.