A zinc-mediated deprotective annulation approach to new polycyclic heterocycles
A straightforward approach to new polycyclic heterocycles, 1H-benzo[4,5]imidazo[1,2-c][1,3]oxazin-1-ones, is presented. It is based on the ZnCl-promoted deprotective 6-endo-dig het-erocyclization of N-Boc-2-alkynylbenzimidazoles under mild conditions (CHCl, 40C for 3 h). The zinc center plays a dual role, as it promotes Boc deprotection (with formation of the tert-butyl carbocation, which can be trapped by substrates bearing a nucleophilic group) and activates the triple bond toward intramolecular nucleophilic attack by the carbamate group. The structure of representative products has been confirmed by X-ray diffraction analysis.
Year |
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2021 |
Journal |
Molecules (Basel, Online) |
Impact factor
4.927
RESEARCH AREA
KEYWORDS
Authors
Veltri L.; Amuso R.; Petrilli M.; Cuocci C.; Chiacchio M.A.; Vitale P.; Gabriele B.
Authors IC CNR