Abstract
We report herein the synthesis of N-substituted indoles resulting from the ring-closing metathesis of indole precursors bearing N-terminal alkenes. The aqueous metathesis of the indole precursors gave good yields of N-substituted indoles (up to 72%) with commercial metathesis catalysts and with artificial metalloenzymes based on the biotin-streptavidin technology. Strikingly, the yield of the N-acetylindole increases in presence of a second metathesis substrate.
Highlights
Indoles are important synthetic scaffolds [1,2]
Based on the work of Nishida and coworkers [8], starting form o-nitrobenzaldehyde 1, we reproduced the synthesis of the two substituted indoles 7a-b by generating the indole precursors 6a-b containing an internal alkene via a Ru-H promoted isomerization (Scheme 2) [21,22,23,24]
The RCM activity assay reveals modest to good yields of indole 7b with four metathesis catalysts, among which G-II (10 mol % catalyst loading) gave the highest yield of Nacetylindole (72 %, Table 2, entry 6)
Summary
Indoles are important synthetic scaffolds [1,2]. The indole core is present in many compounds which possess biological activity, such as naturally-occurring alkaloids and chemotherapeutic drugs [3,4,5,6]. The RCM activity assay reveals modest to good yields of indole 7b with four metathesis catalysts, among which G-II (10 mol % catalyst loading) gave the highest yield of Nacetylindole (72 %, Table 2, entry 6). The water-soluble catalyst Aquamet (5 mol % catalyst loading) afforded 66 % of indole 7b (Table 2, entry 7).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: 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.
