Catalytic dehydrocoupling of Amine-Boranes Using Cationic Zirconium(IV)-Phosphine Frustrated Lewis Pairs

Owen J Metters, Stephanie R Flynn, Christiana Dowds, Hazel A Sparkes, Ian Manners, Duncan F Wass

Research output: Contribution to journalArticle (Academic Journal)peer-review

21 Citations (Scopus)
425 Downloads (Pure)

Abstract

A series of novel, intramolecular Zr(IV)/P frustrated Lewis pairs (FLPs) based on cationic zirconocene fragments with a variety of ancillary cyclopentadienyl and 2-
phosphinoaryloxide (−O(C6H4)PR2, R = tBu and 3,5-CF3- (C6H3)) ligands are reported and their activity as catalysts for the dehydrocoupling of dimethylamine−borane (Me2NH·BH3) assessed. The FLP system [(C9H7)2ZrO(C6H4)PtBu2]-[B(C6F5)4] is shown to give unprecedented turnover
frequencies (TOF) for a catalyst based on a group 4 metal (TOF ≥ 600 h−1), while also proving to be the most efficient FLP catalyst reported to date. The mechanism of this reaction has been probed using analogous intermolecular Zr(IV)/P FLPs, permitting deconvolution of the reactions taking place at both the Lewis acidic and basic sites. Elucidation of this mechanism revealed an interesting cooperative two-cycle process where one cycle is FLP mediated and the other, a redistribution of a linear diborazane intermediate, relies solely on the presence of a Zr(IV) Lewis acid.
Original languageEnglish
Pages (from-to)6601-6611
Number of pages11
JournalACS Catalysis
Volume6
Early online date9 Aug 2016
DOIs
Publication statusPublished - 7 Oct 2016

Keywords

  • amine−borane
  • dehydrocoupling
  • FLP
  • frustrated Lewis pairs
  • zirconocenes

Fingerprint Dive into the research topics of 'Catalytic dehydrocoupling of Amine-Boranes Using Cationic Zirconium(IV)-Phosphine Frustrated Lewis Pairs'. Together they form a unique fingerprint.

Cite this