Experimental and theoretical insights into the synthesis of α-aminoalkyl naphthol derivatives catalyzed by a manganese complex immobilized on multi-walled carbon nanotubes

Abstract

The full details of the synthesis of α-aminoalkyl naphthol derivatives promoted by a manganese complex immobilized on multi-walled carbon nanotubes (CNTs@Mn-bpy) are described, with a particular focus on theoretical mechanistic aspects. After characterization studies on the nanocatalyst prepared from a homogeneous manganese complex, we optimized the catalytic reaction conditions, and the heterogeneous nanocatalyst showed important features such as higher efficiency and reusability compared to other reported catalysts. α-Aminoalkyl naphthol derivatives were obtained in excellent chemical yields and short reaction times and with high turnover numbers. In order to better understand the effect of CNT@Mn-bpy as a nanocatalyst on the reaction mechanism, the final step of the described synthesis has been investigated using density functional theory (DFT). Compared to the uncatalyzed reaction, the activation energy of the catalyzed reaction is lowered by 34.07 kcal mol⁻¹. Also, our theoretical calculation shows that if the Mn metal of CNT@Mn-bpy is replaced with the Cu metal, the catalytic effect of this nanocatalyst on the activation energy of the studied reaction was significantly decreased.