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

Abstract

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.

Metadata

Item Type:	Article
Authors/Creators:	Ryan, David E. Andrea, Kori A. Race, James J. Boyd, Timothy M. Lloyd-Jones, Guy C. Weller, Andrew S. https://orcid.org/0000-0003-1646-8081
Copyright, Publisher and Additional Information:	© 2020 American Chemical Society
Keywords:	amine-borane,dehydropolymerization,mechanism,phosphine,rhodium
Dates:	Published: 17 July 2020 Published (online): 17 June 2020 Accepted: 15 June 2020
Institution:	The University of York
Academic Units:	The University of York > Faculty of Sciences (York) > Chemistry (York)
Funding Information:	Funder Grant number EPSRC EP/M024210/2
Depositing User:	Pure (York)
Date Deposited:	18 Jun 2020 08:20
Last Modified:	08 Feb 2025 00:38
Published Version:	https://doi.org/10.1021/acscatal.0c02211
Status:	Published
Refereed:	Yes
Identification Number:	10.1021/acscatal.0c02211
Related URLs:	http://www.scopus.com/inward/record.url?...
Open Archives Initiative ID (OAI ID):	oai:eprints.whiterose.ac.uk:162033