Copper(II)-Catalyzed (3+2) Cycloaddition of 2 H-Azirines to Six-Membered Cyclic Enols as a Route to Pyrrolo[3,2- c]quinolone, Chromeno[3,4- b]pyrrole, and Naphtho[1,8- ef]indole Scaffolds

Pavel A Sakharov; Nikolai V Rostovskii; Alexander F Khlebnikov; Mikhail S Novikov

doi:10.3390/molecules27175681

Copper(II)-Catalyzed (3+2) Cycloaddition of 2 H-Azirines to Six-Membered Cyclic Enols as a Route to Pyrrolo[3,2- c]quinolone, Chromeno[3,4- b]pyrrole, and Naphtho[1,8- ef]indole Scaffolds

Molecules. 2022 Sep 2;27(17):5681. doi: 10.3390/molecules27175681.

Authors

Pavel A Sakharov¹, Nikolai V Rostovskii¹, Alexander F Khlebnikov¹, Mikhail S Novikov¹

Affiliation

¹ Institute of Chemistry, St. Petersburg State University, 7/9 Universitetskaya Nab., 199034 St. Petersburg, Russia.

Abstract

A method for the [2+3] pyrroline annulation to the six-membered non-aromatic enols using 3-aryl-2H-azirines as annulation agents is developed in the current study. The reaction proceeds as a formal (3+2) cycloaddition via the N1-C2 azirine bond cleavage and is catalyzed by both Cu(II) and Cu(I) compounds. The new annulation method can be applied to prepare pyrrolo[3,2-c]quinoline, chromeno[3,4-b]pyrrole, and naphtho[1,8-ef]indole derivatives in good to excellent yields from enols of the quinolin-2-one, 2H-chromen-2-one, and 1H-phenalen-1-one series.

Keywords: annulation; azirines; copper catalysis; cycloaddition; pyrrolines.

MeSH terms

Azirines* / chemistry
Catalysis
Copper / chemistry
Cycloaddition Reaction
Indoles / chemistry
Pyrroles / chemistry
Quinolones*

Substances

Azirines
Indoles
Pyrroles
Quinolones
Copper

Grants and funding

20-13-00044/Russian Science Foundation