Synthesis of 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols through regioselective Friedel–Crafts alkylation of indoles with β-(trifluoroacetyl)coumarins catalyzed by Sc(OTf)3. Issue 24 (15th April 2020)

• Record Type: Journal Article
• Authors: Shi, Lijun; Liu, Ying; Wang, Caixia; Yuan, Xinxin; Liu, Xiaobiao; Wu, Lulu; Pan, Zhenliang; Yu, Qicheng; Xu, Cuilian; Yang, Guoyu
• Is Part Of: RSC advances. Volume 10:Issue 24(2020)
• Page Start: 13929
• Page End: 13935
• Publication Date: 2020-04-15
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra01237h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A Friedel–Crafts alkylation of indoles with β-(trifluoroacetyl)coumarins catalyzed by Sc(OTf)3 to afford 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols in a short time and high yield was developed. Abstract : A highly efficient Friedel–Crafts alkylation of indole derivatives with β-(trifluoroacetyl)coumarins using Sc(OTf)3 as a catalyst has been developed, which gives regioselective 1, 2-adducts to afford 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols. A series of tertiary trifluoroethanols containing different indole and coumarin groups were synthesized in moderate to excellent yields (up to 95%) in the presence of 5 mol% catalyst in a short time (only 2 minutes at least). A mechanism of the reaction, in which the trace amount of water plays the role of proton transfer in catalyzing circulation was proposed and confirmed.