Abstract

AbstractThe multi‐component Friedel–Crafts alkylation reaction between indole (1), ethyl glyoxylate (2) and anilines (3a–f) gives, in analogy to the protocol of the old Passerini reaction, the expected ethyl 2‐(arylamino)‐2‐(1H‐indol‐3‐yl)acetates 4a–f. When the reactions are catalysed by 5 mol‐% scandium triflate (ScIIITf), however, or when the isolated products 4 are treated under the same conditions, rearrangements involving the arylamino fragments of adducts 4 take place. When the para position of 4 is unsubstituted, ethyl 2‐(2‐aminoaryl)‐2‐(1H‐indol‐3‐yl) acetates 5 are obtained, and their structures were confirmed by the X‐ray crystal structure analysis of 5a. Under milder conditions, ScIIITf gives more complicated products, deriving from 1, 2 and 3 in the ratio of 2:2:1, and these converted into 5. An explanation of the pathway, by which the Passerini adducts 4, coordinated to scandium, undergo the rearrangements, is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.