Wow! Nitroethene is sufficiently electrophilic to substitute indole without the need of acid catalyst, the yield is 80% at room temperature:
(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000444232-file_fm8i.jpg)I'll bee back with the detailed experimental procedure...
Yup, it is - a lot of Repke's publications use this synthon for making tryptamines. 1-Dimethylamino-2-nitroethene (DMANE) is also pretty good:
https://www.thevespiary.org/rhodium/Rhodium/chemistry/dmane.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/dmane.html)
Tryptamine, synthesis starting with nitroethylene and indole: Noland, Hartman, J. Am. Chem. Soc. 76, 3227 (1954)
The Nitroethylation of Indole. A New Synthesis of Tryptamine. Wayland E. Noland, Philip J. Hartman J. Am. Chem. Soc. 76(12), 3227-3228 (1954) (https://www.thevespiary.org/rhodium/Rhodium/pdf/tryptamine.indole.nitroethylation.pdf)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/tryptamine.indole.nitroethylation.pdf)
Edit: I have backed up the great article from pHarmacist's post below to my page for safekeeping:
JOC 45, 1185-1189 (1980) (https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethene.in.organic.synthesis.pdf)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethene.in.organic.synthesis.pdf)
Nitroethylene: A Stable, Clean, and Reactive Agent for Organic Synthesis
J . Org. Chem. 1980,45, 1185-1189
_________
Full-text:
http://pharmacist8.tripod.com/jo01295a003.pdf (http://pharmacist8.tripod.com/jo01295a003.pdf)
