Generalized ring‐opening mechanism in cycloolefin polymerizations

Abstract
Ring‐opening polymerizations of cycloolefins under low strain induced by tungsten based Ziegler‐Natta catalysts were previously shown to proceed via metathesis. Now, these investigations have been extended to highly strained four‐membered rings and to molybdenum‐, titanium‐, and ruthenium‐based ring‐opening catalysts. Ozonolysis of 1[14C] cyclobutene‐3‐methylcyclobutene copolymers confirmed the general validity of the metathesis mechanism.