Everything is Falling into Place!

Significance

The Brookhart catalyst system is shown to efficiently catalyze the cyclopolymerization of functionalized trienes. The resulting polymers exclusively exhibit racemo (rather than meso) stereochemistry and display modest tacticity. The authors propose that the high stereoselectivity is a result of the rapid rate of migratory insertion versus the rate of β-hydride elimination during the cyclization process. The post-polymerization hydrolysis of a cyclic acetal functional group is also described, thus permitting access to additional modifications.