Catalyst-free Tandem 1,3-Dipolar Cycloaddition/Aldol Condensation: Diastereoselective Construction of the
Nikolay S Zimnitskiy1, Andrey D Denikaev1, Alexey Y Barkov1
1Institute of Natural Sciences and Mathematics, Ural Federal University, pr. Lenina 51, 620000 Ekaterinburg, Russian Federation.
Abstract:
The one-pot regioselective and diastereoselective method for the synthesis of 5-(het)aroyl-7-(het)arylhexahydrobenzo[4,5]pentaleno[1,6a-b](thia)pyrrolizine-6,12-diones from accessible 1,5-di(het)arylpent-4-ene-1,3-diones or curcuminoids in 38-98% yield was developed. This reaction proceeds as a sequence of 1,3-dipolar cycloaddition of azomethine ylide generated in situ from ninhydrin and (thia)proline at the C═C bond of corresponding enedione, followed by spontaneous intramolecular aldol condensation and leads to the formation of an azatetraquinane scaffold.
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