Experimental results and computational insight into sequential reactions of β-(2-aminophenyl)-α,β-ynones with aryl
Antonio Arcadi1, Massimiliano Aschi1, Marco Chiarini2
1Dipartimento di Scienze Fisiche e Chimiche Università degli Studi di L'Aquila, Via Vetoio, 67100 Coppito, AQ, Italy. antonio.arcadi@univaq.it massimiliano.aschi@univaq.it.
Abstract:
The investigation on tandem addition/cyclization reactions of β-(2-aminophenyl)-α,β-ynones with aryl isocyanates/benzoyl isothiocyanate is reported. Experimental results show the suitable conditions to selectively direct the reaction outcome towards the product of 6-exo-dig N-, O-, or S-annulation of the in situ generated alkynyl urea/thiourea intermediate. The reaction of a variety of β-(2-aminophenyl)-α,β-ynones with aryl isocyanates/benzoyl isothiocyanate led to the selective formation of quinazoline or benzoxazine/benzothiazine derivatives, respectively. Density functional theory calculations provide a plausible rationale for the reaction outcome.
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