Synthesis of Helical Polyisocyanide with Alkyne End-Group Using Grignard Reaction

Abstract

we could synthesize PI with alkyne terminal group by applying Grignard reaction. The Ni-Br bond at the polymer chain ends reacted with alkyne containing Grignard reagent, and the following reductive elimination rendered the PI with alkyne terminal group. However, the generated PI-alkyne adducts underwent dimerization process catalyzed by the resulting Ni(0) complexes. The phenomenon could be prevented by adding additional PMe3 ligands during the Grignard reaction, and resulting polymer showed well-defined MW, narrow MW distribution, and terminal alkyne groups. The current system provided simple route to form end-functionalized helical polymers using well-known chemistry. The resulting polymers might find its uses in preparing helical-coil block copolymer with coil polymers via Click chemistry.