Alkaline-Earth Derivatives of Diphenylphosphine-Borane

Louis J. Morris; Michael S. Hill; Mary F. Mahon; Ian Manners; Brian O. Patrick

doi:10.1021/acs.organomet.0c00008

Alkaline-Earth Derivatives of Diphenylphosphine-Borane

Louis J. Morris
, Michael S. Hill
, Mary F. Mahon
, Ian Manners
, Brian O. Patrick

University of Victoria
University of British Columbia

Research output: Contribution to journal › Article › peer-review

15 Citations (SciVal)

253 Downloads (Pure)

Abstract

Treatment of β-diketiminato (BDI = HC{C(CH₃)Ndipp)}₂ where dipp = 2,6-iPr₂C₆H₃) magnesium butyl [(BDI)MgBu] (I) and calcium hexamethyldisilazide [(BDI)Ca{N(SiMe₃)₂}] (II) complexes with equimolar quantities of diphenylphosphine-borane, Ph₂PH·BH₃, results in the formation of the respective alkaline earth (Ae) phosphidoborane derivatives [(BDI)Mg(Ph₂PBH₃)]₂ (6a) and [(BDI)Ca(Ph₂PBH₃)] (7a). Although satisfactory single crystals of 7a could not be obtained, 6a was crystallographically characterized and both compounds display similar NMR spectra. The dimeric Ae-hydride complexes [(BDI)AeH]₂ (IIIa, Ae = Mg; IIIb, Ae = Ca) react with substoichiometric quantities of Ph₂PH·BH₃, allowing the crystallization of the dimeric Mg and trimeric Ca phosphidoborane species [(BDI)Mg(H)(H₃BPPh₂)Mg(BDI)] (8) and [{(BDI)Ca}₃(H)(H₃BPPh₂)₂] (9). In the absence of coordinating Lewis bases, compounds 6a, 7a, 8, and 9 display dynamic solution-state behavior (in benzene and toluene), while addition of THF furnishes the monomeric adducts [(BDI)Mg(H₃BPPh₂)·THF] (6b) and [(BDI)Ca(H₃BPPh₂)·THF] (7b). Addition of Ph₂PH·BH₃ to compound 6a results in BH₃ transfer to eliminate Ph₂PH and generate the phosphinodiboronate complex [(BDI)Mg{(H₃B)₂PPh₂}]₂ (10) in preference to dehydrocoupling of the phosphidoborane and phosphine-borane reagents.

Original language	English
Pages (from-to)	4195-4207
Journal	Organometallics
Volume	39
Issue number	23
Early online date	19 Feb 2020
DOIs	https://doi.org/10.1021/acs.organomet.0c00008
Publication status	Published - 14 Dec 2020

Funding

Financial support was provided by the EPSRC though grant number EP/N014456/1 and the Center for Doctoral Training in Catalysis (EP/L016443/1). I.M. thanks the University of Bristol for support and the Canadian Government for a C150 Research Chair.

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Organic Chemistry
Inorganic Chemistry

Access to Document

10.1021/acs.organomet.0c00008

Ae phosphidoboranes_OM.pdf
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.organomet.0c00008
Accepted author manuscript, 1.2 MB

Cite this

@article{24b5e693e1ea409fb0b4de29ad380047,

title = "Alkaline-Earth Derivatives of Diphenylphosphine-Borane",

abstract = "Treatment of β-diketiminato (BDI = HC\{C(CH3)Ndipp)\}2 where dipp = 2,6-iPr2C6H3) magnesium butyl [(BDI)MgBu] (I) and calcium hexamethyldisilazide [(BDI)Ca\{N(SiMe3)2\}] (II) complexes with equimolar quantities of diphenylphosphine-borane, Ph2PH·BH3, results in the formation of the respective alkaline earth (Ae) phosphidoborane derivatives [(BDI)Mg(Ph2PBH3)]2 (6a) and [(BDI)Ca(Ph2PBH3)] (7a). Although satisfactory single crystals of 7a could not be obtained, 6a was crystallographically characterized and both compounds display similar NMR spectra. The dimeric Ae-hydride complexes [(BDI)AeH]2 (IIIa, Ae = Mg; IIIb, Ae = Ca) react with substoichiometric quantities of Ph2PH·BH3, allowing the crystallization of the dimeric Mg and trimeric Ca phosphidoborane species [(BDI)Mg(H)(H3BPPh2)Mg(BDI)] (8) and [\{(BDI)Ca\}3(H)(H3BPPh2)2] (9). In the absence of coordinating Lewis bases, compounds 6a, 7a, 8, and 9 display dynamic solution-state behavior (in benzene and toluene), while addition of THF furnishes the monomeric adducts [(BDI)Mg(H3BPPh2)·THF] (6b) and [(BDI)Ca(H3BPPh2)·THF] (7b). Addition of Ph2PH·BH3 to compound 6a results in BH3 transfer to eliminate Ph2PH and generate the phosphinodiboronate complex [(BDI)Mg\{(H3B)2PPh2\}]2 (10) in preference to dehydrocoupling of the phosphidoborane and phosphine-borane reagents.",

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T1 - Alkaline-Earth Derivatives of Diphenylphosphine-Borane

AU - Morris, Louis J.

AU - Hill, Michael S.

AU - Mahon, Mary F.

AU - Manners, Ian

AU - Patrick, Brian O.

PY - 2020/12/14

Y1 - 2020/12/14

N2 - Treatment of β-diketiminato (BDI = HC{C(CH3)Ndipp)}2 where dipp = 2,6-iPr2C6H3) magnesium butyl [(BDI)MgBu] (I) and calcium hexamethyldisilazide [(BDI)Ca{N(SiMe3)2}] (II) complexes with equimolar quantities of diphenylphosphine-borane, Ph2PH·BH3, results in the formation of the respective alkaline earth (Ae) phosphidoborane derivatives [(BDI)Mg(Ph2PBH3)]2 (6a) and [(BDI)Ca(Ph2PBH3)] (7a). Although satisfactory single crystals of 7a could not be obtained, 6a was crystallographically characterized and both compounds display similar NMR spectra. The dimeric Ae-hydride complexes [(BDI)AeH]2 (IIIa, Ae = Mg; IIIb, Ae = Ca) react with substoichiometric quantities of Ph2PH·BH3, allowing the crystallization of the dimeric Mg and trimeric Ca phosphidoborane species [(BDI)Mg(H)(H3BPPh2)Mg(BDI)] (8) and [{(BDI)Ca}3(H)(H3BPPh2)2] (9). In the absence of coordinating Lewis bases, compounds 6a, 7a, 8, and 9 display dynamic solution-state behavior (in benzene and toluene), while addition of THF furnishes the monomeric adducts [(BDI)Mg(H3BPPh2)·THF] (6b) and [(BDI)Ca(H3BPPh2)·THF] (7b). Addition of Ph2PH·BH3 to compound 6a results in BH3 transfer to eliminate Ph2PH and generate the phosphinodiboronate complex [(BDI)Mg{(H3B)2PPh2}]2 (10) in preference to dehydrocoupling of the phosphidoborane and phosphine-borane reagents.

AB - Treatment of β-diketiminato (BDI = HC{C(CH3)Ndipp)}2 where dipp = 2,6-iPr2C6H3) magnesium butyl [(BDI)MgBu] (I) and calcium hexamethyldisilazide [(BDI)Ca{N(SiMe3)2}] (II) complexes with equimolar quantities of diphenylphosphine-borane, Ph2PH·BH3, results in the formation of the respective alkaline earth (Ae) phosphidoborane derivatives [(BDI)Mg(Ph2PBH3)]2 (6a) and [(BDI)Ca(Ph2PBH3)] (7a). Although satisfactory single crystals of 7a could not be obtained, 6a was crystallographically characterized and both compounds display similar NMR spectra. The dimeric Ae-hydride complexes [(BDI)AeH]2 (IIIa, Ae = Mg; IIIb, Ae = Ca) react with substoichiometric quantities of Ph2PH·BH3, allowing the crystallization of the dimeric Mg and trimeric Ca phosphidoborane species [(BDI)Mg(H)(H3BPPh2)Mg(BDI)] (8) and [{(BDI)Ca}3(H)(H3BPPh2)2] (9). In the absence of coordinating Lewis bases, compounds 6a, 7a, 8, and 9 display dynamic solution-state behavior (in benzene and toluene), while addition of THF furnishes the monomeric adducts [(BDI)Mg(H3BPPh2)·THF] (6b) and [(BDI)Ca(H3BPPh2)·THF] (7b). Addition of Ph2PH·BH3 to compound 6a results in BH3 transfer to eliminate Ph2PH and generate the phosphinodiboronate complex [(BDI)Mg{(H3B)2PPh2}]2 (10) in preference to dehydrocoupling of the phosphidoborane and phosphine-borane reagents.

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DO - 10.1021/acs.organomet.0c00008

M3 - Article

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JO - Organometallics

JF - Organometallics

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ER -

Alkaline-Earth Derivatives of Diphenylphosphine-Borane

Abstract

Funding

ASJC Scopus subject areas

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Nucleophilic alkaline earth boryls: from conception and theory to application

Augmentation of Alkaline Earth Reactivity: An FLP Analogy

Propulse 500 MHz Nuclear Magnetic Resonance (NMR) Spectrometer (1South)

Cite this

Alkaline-Earth Derivatives of Diphenylphosphine-Borane

Abstract

Funding

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Projects

Nucleophilic alkaline earth boryls: from conception and theory to application

Augmentation of Alkaline Earth Reactivity: An FLP Analogy

Equipment

Propulse 500 MHz Nuclear Magnetic Resonance (NMR) Spectrometer (1South)

Cite this