Dendritic Stars by Ring‐Opening‐Metathesis Polymerization from Ruthenium–Carbene Initiators

A star in the making: A new ruthenium–carbene complex has been synthesized by using a diphosphane ligand that models the dendritic branch of poly(diphosphane) dendrimers. First, second, and third generation metallodendrimers derived from diaminobutane polyamines, with 4, 8, and 16 ruthenium-containing branches, respectively, have been synthezised and shown to initiate the ring-opening-metathesis polymerization (ROMP) of norbornene at room temperature to form metallodendritic polymer stars (see scheme; P=PCy2).