Tetrabutylammonium decatungstate (TBADT) has emerged as a valuable photocatalyst for sunlight-induced organic reactions. In this communication we wish to present its use for the photocatalytic oxidation of hydroxamic acids to generate fleeting nitrosocarbonyl intermediates. The reaction required a fine tuning of the conditions, especially in terms of solvent and additives, since an aqueous acetonitrile solution containing a mild base (NaHCO3) gave the best results. The obtained highly reactive nitrosocarbonyl species were then efficiently trapped with suitable dienes, such as cyclopentadiene and 1,3-cyclohexadiene, to afford the corresponding Hetero Diels–Alder (HDA) cycloadducts in good yields. Dedicated photophysical experiments helped to elucidate the mechanistic scenario.
Photocatalyzed Generation of Nitrosocarbonyl Intermediates Under Solar Light Irradiation
Teresa Basile;Luca Capaldo;Davide Ravelli
;Paolo Quadrelli
2020-01-01
Abstract
Tetrabutylammonium decatungstate (TBADT) has emerged as a valuable photocatalyst for sunlight-induced organic reactions. In this communication we wish to present its use for the photocatalytic oxidation of hydroxamic acids to generate fleeting nitrosocarbonyl intermediates. The reaction required a fine tuning of the conditions, especially in terms of solvent and additives, since an aqueous acetonitrile solution containing a mild base (NaHCO3) gave the best results. The obtained highly reactive nitrosocarbonyl species were then efficiently trapped with suitable dienes, such as cyclopentadiene and 1,3-cyclohexadiene, to afford the corresponding Hetero Diels–Alder (HDA) cycloadducts in good yields. Dedicated photophysical experiments helped to elucidate the mechanistic scenario.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
