Diversity‐Oriented Post‐Polymerization Modifications by Developing <i>gem</i> ‐Diboryl Polyolefin as a Platform Polymer

Abstract Post‐polymerization modification (PPM) serves as a pivotal synthetic strategy for generating libraries of functional polymers from commodity precursors. The pursuit of practical and efficient PPM methods remains a longstanding objective in polymer chemistry. Herein, we report a novel diversity‐oriented post‐polymerization modification (DOPPM) protocol utilizing gem ‐diboryl polyolefin as a platform polymer. This polymer is readily synthesized via radical ring‐opening polymerization of a gem ‐diboryl‐substituted vinylcyclo‐propane monomer. Density functional theory calculations reveal that the diboryl moiety effectively stabilizes the ring‐opened propagating radical intermediate during polymerization, thereby promoting linear chain growth while suppressing competing 4‐endo‐trig cyclization that would lead to cyclic polymer formation. The gem ‐diboryl polyolefin exhibits exceptional reactivity and versatility in DOPPM, enabling its conversion into a wide range of functional polyolefins inaccessible via existing methods.