Date of Original Version
Two new syntheses for 2,2'-biindoles are reported. The first uses a palladium catalyzed annulation of a bis(o-iodophenyl)-α,β-diimine. The method employs mild conditions, gives good yields, and is potentially tolerant of a variety of substituent groups. The second method uses a Wittig reaction between a 2-nitrobenzylphosphonium salt and 2-nitrocinnamaldehyde to form 1,4-bis(2-nitrophenyl)butadiene, which followed by triethylphosphite cyclization to give the biindole.
Publication Title, e.g., Journal
Koza, Darrell J., and William B. Euler. "Convenient syntheses of 2,2'-biindole." Heterocyclic Communications 5, 5 (1999): 399-402. doi: 10.1515/HC.19184.108.40.2069.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.