Narrowly distributed homotelechelic polymers in 30 minutes: Using fast in situ pre‐functionalized ROMP initiators

Today's olefin metathesis catalysts show high reactivity, selectivity, and functional group tolerance, and allow the design of new syntheses of precisely functionalized polymers. Here we describe a general “one‐pot” synthesis for narrow polydispersity bis‐end‐functional (=homotelechelic) ROMP polymers exploiting the propagating ruthenium complex inherent selectivity for strained norbornenes over acyclic internal olefins. This approach represents a straightforward general method of homotelechelic polymers carrying almost any functional end group (within the limitations of the catalyst's functionality tolerance). Complete pre‐functionalization of the initiator is realized in situ within minutes and without the need of further purification steps. The excess acyclic olefin re‐enters the catalytic cycle after monomer consumption is complete giving a homotelechelic polymer. 1 H NMR spectroscopic and MALDI‐ToF‐MS analysis show highly efficient end group functionalization. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51 , 4183–4190