Amine-Borane Dehydropolymerization Using Rh-Based Precatalysts: Resting State, Chain Control, and Efficient Polymer Synthesis

David E. Ryan, Kori A. Andrea, James J. Race, Timothy M. Boyd, Guy C. Lloyd-Jones, Andrew S. Weller*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A detailed study of H3B·NMeH2 dehydropolymerization using the cationic pre-catalyst [Rh(DPEphos)(H2BNMe3(CH2)2tBu)]-[BArF4], identifies the resting state as dimeric [Rh(DPEphos)H2]2 and boronium [H2B(NMeH2)2]+ as the chain-control agent. [Rh(DPEphos)H2]2 can be generated in situ from Rh(DPEphos)(benzyl), and catalyzes polyaminoborane formation (H2BNMeH)n [Mn = 15000 g mol–1]. Closely-related Rh(Xantphos)(benzyl) operates at 0.1 mol%, to give higher molecular weight polymer [Mn = 85000 g mol–1] on gram scale with low residual [Rh], 81 ppm. This insight offers a mechanistic template for dehydropolymerization.
Original languageEnglish
Pages (from-to)7443-7448
Number of pages6
JournalACS Catalysis
Issue number14
Early online date17 Jun 2020
Publication statusPublished - 17 Jul 2020

Bibliographical note

© 2020 American Chemical Society


  • amine-borane
  • dehydropolymerization
  • mechanism
  • phosphine
  • rhodium

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