Ru-Catalyzed Polycondensation of Dialkyl 1,4-Phenylenebis(diazoacetate) with Dianiline: Synthesis of Well-Defined Aromatic Polyamines Bearing an Alkoxycarbonyl Group at the Adjacent Carbon of Each Nitrogen in the Main Chain Framework

Transition-metal-catalyzed N–H insertion of a diazocarbonyl compound is applied for polycondensation for the first time to give a new type of aromatic polyamine. The well-defined polyamines were obtained by [RuCl₂(p-cymene)]₂-catalyzed reaction of diethyl 1,4-phenylenebis­(diazoacetate) with dianilines bearing a variety of linkers between two aniline units. The polycondensation proceeded at 30 °C in CH₂Cl₂ with 5.0 mol % of the Ru metal to [NH₂ or N₂C] to afford the products with M_n = 6400–28 300 in moderate to high yield. Ethoxycarbonyl groups located at an adjacent position to NH imparted solubility to the polyamines, and their glass transition temperatures can be varied depending on the linker structure in a range of 88–173 °C.