Water reduction and dihydrogen addition in aqueous conditions with ansa-phosphinoborane
|Author:||Sorochkina, Kristina1; Chernichenko, Konstantin1,2; Zhivonitko, Vladimir V.3;|
1Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, 00014 Helsinki, Finland
2Chemical Process Research and Development Janssen Pharmaceutica, Turnhoutseweg 30, 2340 Beerse, Belgium
3NMR Research Unit, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 3.3 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2023062759462
John Wiley & Sons,
|Publish Date:|| 2023-06-27
Ortho-phenylene-bridged phosphinoborane (2,6-Cl₂Ph)₂B-C₆H₄-PCy₂ 1 was synthesized in three steps from commercially available starting materials. 1 reacts with H2 or H2O under mild conditions to form corresponding zwitterionic phosphonium borates 1-H₂ or 1-H₂O. NMR studies revealed both reactions to be remarkably reversible. Thus, when exposed to H₂, 1-H₂O partially converts to 1-H₂ even in the presence of multiple equivalents of water in the solution. The addition of parahydrogen to 1 leads to nuclear spin hyperpolarization both in dry and hydrous solvents, confirming the dissociation of 1-H₂O to free 1. These observations were supported by computational studies indicating that the formation of 1-H₂ and 1-H₂O from 1 are thermodynamically favored. Unexpectedly, 1-H₂O can release molecular hydrogen to form phosphine oxide 1-O. Kinetic, mechanistic, and computational (DFT) studies were used to elucidate the unique “umpolung” water reduction mechanism.
Chemistry. A European journal
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
116 Chemical sciences
We are grateful for financial support from the Academy of Finland (grant 139550, 276586 and 316207). The authors wish to acknowledge CSC – IT Center for Science, Finland, for computational resources (CSC projects 2000358 and 2000926). V.V.Z. acknowledges the financial support from the Academy of Finland (grant 323480) and the University of Oulu (Kvantum Institute).
|Academy of Finland Grant Number:||
323480 (Academy of Finland Funding decision)
© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.