Synthesis, 1H NMR and X-ray crystallographic studies of three isomeric butylidene linker protophanes

Abstract

In this study, the synthesis of isomeric butylidene linker protophanes by the reaction of butylidene linker bis-lactam with n-propyl iodide in K2CO3/DMF is reported. All the three isomers showed folded (syn) conformation in solution based on 1H NMR analysis. More importantly, this folding carries over to the solid state due to intramolecular ππ interactions as revealed by single crystal X-ray crystallography.