Scientific article
Open access

Regiodivergent synthesis of pyrazino-indolines vs. triazocines via α-imino carbenes addition to imidazolidines

Published inChemical Science, vol. 12, no. 4, p. 1479-1485
Publication date2021

Hexahydropyrazinoindoles were prepared in a single step from N-sulfonyl triazoles and imidazolidines. Under dirhodium catalysis, α-imino carbenes were generated and formed nitrogen ylide intermediates that, after subsequent aminal opening, afforded the pyrazinoindoles predominantly via formal [1,2]-Stevens and tandem Friedel–Crafts cyclizations. Of mechanistic importance, a regiodivergent reactivity was engineered through the use of a specific unsymmetrically substituted imidazolidine that promoted the exclusive formation of 8-membered ring 1,3,6-triazocines. Based on DFT calculations, an original Curtin–Hammett-like situation was demonstrated for the mechanism. Further derivatizations led to functionalized tetrahydropyrazinoindoles in high yields.

Citation (ISO format)
GUARNIERI IBANEZ, Alejandro José et al. Regiodivergent synthesis of pyrazino-indolines <i>vs.</i> triazocines <i>via</i> α-imino carbenes addition to imidazolidines. In: Chemical Science, 2021, vol. 12, n° 4, p. 1479–1485. doi: 10.1039/D0SC05725H
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Article (Published version)
ISSN of the journal2041-6520

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Creation02/05/2021 11:03:00 AM
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