Quantum‐Chemical Insight into Self‐Organization of Complex Molecules from Acetylene and Anilines Catalyzed by Superbase KOH/DMSO: One‐Pot Cascade Assembly of 1,3‐Bis(arylamines)

Abstract

The self‐organization of functionalized diamines, 1‐acetyl‐1,3‐bis(haloarylamines), from three molecules of acetylene and two molecules of haloanilines in the KOH/DMSO superbase medium, has been analyzed quantum chemically in some detail in the framework of the B2PLYP(D3)/6‐311+G**//B3LYP/6‐31+G* approach. We have established that the diamines are constructed in a cascade manner via the sequential alternating additions of haloaniline anions to acetylene. The reaction sequence is catalyzed by a superbase pentacoordinated complex, KOH ⋅ 5DMSO, where the hydroxide ion is significantly separated from the potassium cation (the K−OH bond length is by 0.4–0.5 Å longer than in the bare KOH molecule). The latter imparts pronounced superbasicity to the complex and provides for a shuttle‐like proton transfer (H++OH−=H2O) during the whole cascade process.