An Unprecedented Pseudo-[3+2] Annulation between N-(4-Methoxyphenyl)aldimines and Aqueous Glutaraldehyde: Direct Synthesis of Pyrrole-2,4-dialdehydes was written by Ramaraju, Panduga;Mir, Nisar A.;Singh, Deepika;Sharma, Preetika;Kant, Rajni;Kumar, Indresh. And the article was included in European Journal of Organic Chemistry in 2017.Electric Literature of C8H6FNO This article mentions the following:
A new method for the direct one-pot synthesis of substituted pyrrole-2,4-dialdehdyes was developed. This overall pseudo-[3+2]-annulation reaction between glutaraldehyde and N-(4-methoxyphenyl)aldimines proceeds through proline-catalyzed direct Mannich reaction/cyclization, followed by 2-iodoxybenzoic acid mediated oxidative rearrangement of the in situ generated intermediate to give pyrrole-2,4-dialdehydes in high yields (up to 80 %). In the experiment, the researchers used many compounds, for example, 5-Fluoroindolin-2-one (cas: 56341-41-4Electric Literature of C8H6FNO).
5-Fluoroindolin-2-one (cas: 56341-41-4) belongs to indole derivatives. In addition to tryptophan, indigo, and indoleacetic acid, numerous compounds obtainable from plant or animal sources contain the indole molecular structure. It is used in perfumery and in making tryptophan, an essential amino acid, and indoleacetic acid (heteroauxin), a hormone that promotes the development of roots in plant cuttings.Electric Literature of C8H6FNO
Referemce:
Indole alkaloid derivatives as building blocks of natural products from聽Bacillus thuringiensis聽and聽Bacillus velezensis聽and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles