Phosphinoborane interception at magnesium by borane-assisted phosphine-borane dehydrogenation
| dc.contributor.author | Morris, Louis J. | |
| dc.contributor.author | Rajabi, Nasir A. | |
| dc.contributor.author | Hill, Michael S. | |
| dc.contributor.author | Manners, Ian | |
| dc.contributor.author | McMullin, Claire L. | |
| dc.contributor.author | Mahon, Mary F. | |
| dc.date.accessioned | 2020-11-10T17:34:38Z | |
| dc.date.available | 2020-11-10T17:34:38Z | |
| dc.date.copyright | 2020 | en_US |
| dc.date.issued | 2020 | |
| dc.description.abstract | Reactions of B(C6F5)3 with the β-diketiminato (BDI) alkaline-earth phosphidoborane complexes, 1a [(BDI)Ca(H3B·PPh2)] and 1b [(BDI)Mg(H3B·PPh2)]2 (BDI = [HC{C(CH3)N(2,6-iPr-C6H3)}2]−) result in the formation of phosphinodiboronate complexes 4a [(BDI)Ca(η6-toluene){H3B·PPh2·B(C6F5)3}] and 4b [(BDI)Mg{H3B·PPh2·B(C6F5)3}]. Calcium complex 4a is stable in aromatic solvents at room temperature and does not display well-defined onward reactivity at elevated temperatures. Magnesium complex 4b undergoes a room temperature transformation to provide the known hydridoborate derivative 3b [(BDI)Mg{HB(C6F5)3}] and an N,P,N’-ligated species, 5 [{HC(C(CH3)N(2,6-iPr-C6H3))2(H2BPPh2)}Mg{H3B·PPh2·B(C6F5)3}] that results from interception of the putative phosphinoborane, H2B = PPh2, by the BDI ligand backbone following B(C6F5)3-mediated hydride abstraction. NMR spectroscopic investigations were supported by DFT calculations, which suggested a mechanism involving B(C6F5)3 migration and hydride abstraction within the coordination sphere of magnesium. Interception of H2B = PPh2 by B(C6F5)3 is proposed to stabilise this species, whilst activating it towards ligand-centred nucleophilic attack. The significant stabilisation energy calculated for the Ca-π(toluene) interaction in 4a accounts for the contrasting outcomes between the two Ae-elements. The crystal structures of compounds 4a and 5 are presented and discussed. | en_US |
| dc.description.reviewstatus | Reviewed | en_US |
| dc.description.scholarlevel | Faculty | en_US |
| dc.description.sponsorship | We thank the EPSRC for financial support through the Centre for Doctoral Training in Catalysis (EP/L016443/1) and research grant EP/R020752/1. I. M. thanks the University of Bristol for support and the Canadian Government for a C150 Research Chair. This research made use of the Balena High Performance Computing (HPC) Service at the University of Bath. | en_US |
| dc.identifier.citation | Morris, L. J., Rajabi, N. A., Hill, M. S., Manners, I., McMullin, C. L., & Mahon M. F. (2020). Phosphinoborane interception at magnesium by borane-assisted phosphineborane dehydrogenation. Dalton Transactions, 49(41). https://doi.org/10.1039/d0dt03415k | en_US |
| dc.identifier.uri | https://doi.org/10.1039/d0dt03415k | |
| dc.identifier.uri | http://hdl.handle.net/1828/12327 | |
| dc.language.iso | en | en_US |
| dc.publisher | Dalton Transactions | en_US |
| dc.subject.department | Department of Chemistry | |
| dc.title | Phosphinoborane interception at magnesium by borane-assisted phosphine-borane dehydrogenation | en_US |
| dc.type | Article | en_US |