Pulsed-addition ring-opening metathesis polymerization with functional enyne reagents

Generation of polymers with reduced quantities of metal initiator and control of chain-end functionality remains a challenge for metathesis polymerization techniques. This communication reports the application of functional enyne molecules in pulsed-addition ring-opening metathesis polymerization (PA-ROMP) to generate multiple functional polymer chains from a single 3^rd generation Grubbs initiator. The chain-transfer process is fast and efficient, requiring only 1.2 equivalents of enyne per cycle, and delivers well-defined homopolymers and diblock polymers with low dispersities.