Acid‐catalyzed decomposition and stability of diazofuranones: Experimental and mechanistic study

Abstract

AbstractReactions of substituted 4‐diazotetrahydrofurane‐3‐ones with various acids (pKa < 3) irrespective of acid strength give rise to elimination of nitrogen with subsequent 1,2‐nucleophilic migration of aryl (alkyl) groups from C‐5 to C‐4 position of heterocyclic core with quantitative formation of regioisomeric 3(2Н)furanones (yields up to 99%). Regioselectivity of this acid‐catalyzed process increases with the decreasing of solvent polarity and strongly depends on the nature of substituents in the aryl groups. The suggested mechanism of this reaction via intermediate RN2+ cation was confirmed by density functional theory (DFT) calculations at the PBE0/6‐31+G(d) functional due to good agreement between calculated and experimental data on the acid stability of diazoketones in different solvents.