A novel approach to 5H-pyrazino[2,3-b]indoles via annulation of 3-diazoindolin-2-imines with 2H-azirines or 5-alkoxyisoxazoles under Rh(ii) catalysis

Julia O Ruvinskaya; Nikolai V Rostovskii; Ilya P Filippov; Alexander F Khlebnikov; Mikhail S Novikov

doi:10.1039/c7ob02637d

A novel approach to 5H-pyrazino[2,3-b]indoles via annulation of 3-diazoindolin-2-imines with 2H-azirines or 5-alkoxyisoxazoles under Rh(ii) catalysis

Org Biomol Chem. 2017 Dec 19;16(1):38-42. doi: 10.1039/c7ob02637d.

Authors

Julia O Ruvinskaya¹, Nikolai V Rostovskii, Ilya P Filippov, Alexander F Khlebnikov, Mikhail S Novikov

Affiliation

¹ St. Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia. m.novikov@spbu.ru.

PMID: 29210420
DOI: 10.1039/c7ob02637d

Abstract

A novel one-step method for the preparation of 5H-pyrazino[2,3-b]indoles with different substitution patterns in all rings of the tricyclic system via the Rh₂(OAc)₄-catalyzed reaction of 2H-azirines with 3-diazoindolin-2-imines is reported. Alkyl 5H-pyrazino[2,3-b]indole-3-carboxylates were also prepared by a one-pot procedure from synthetic equivalents of alkyl 2H-azirine-2-carboxylates, 5-alkoxyisoxazoles. The reactions provide the first examples of the use of Rh(ii) catalysis for intermolecular annulations with 2H-azirines and isoxazoles.