Communications

Catalyst-free cyclization of DBU with α,β-ynones: substituent-controlled divergence

O. V. Petrova, I. A. Ushakov, B. A. Trofimov

A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russian Federation

Abstract: 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) cyclizes with α,β-ynones under catalyst-free conditions (MeCN, 3 h) to give a mixture of isolable diverse fused heterocycles including [3 + 3]- and [4 + 2]-cycloadducts as well as DBU ring expansion products, 14- and 15-membered heterocyclic systems incorporating the pyridinone moiety, in 48–58% total yield. Some of the synthesized cycloadducts exhibit blue-green fluorescence with large Stokes shift.

Keywords: 1,8-diazabicyclo[5.4.0]undec-7-ene, ynones, fused heterocyclic system, DBU ring expansion, [3 + 3]- and [4 + 2]-cycloadducts.

Received: 01.07.2025
Accepted: 19.09.2025

Language: English

DOI: 10.71267/mencom.7865