An isolable phosphaethynolato-borane and its reactivity

Journal article

The synthesis and characterization of a stable phosphaethynolato-borane, [B]OCP (1, [B] = N,N'-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaboryl), is described. The increased triple bond character of the P-C bond in 1 relative to the free ion (PCO-) is probed in a series of reactivity studies. Compound 1 readily dimerises in donor solvents to afford a cyclic five-membered 6π-aromatic compound, cyclo-P2{C[B]}O{CO[B]} (2), which decarbonylates on UV irradiation. By contrast the nickel-mediated dimerisation of 1 affords the isomeric diphosphacyclobutene [P(CO[B])]2. When 1 is reacted with organolithium reagents such as MesLi (Mes = 2,4,6-trimethylphenyl), the boryl moiety shifts and the formation of the lithoxy-boryl-phosphaalkene [LiOC[B]P(Mes)]2 was observed. The reactivity of this species towards electrophiles is also described.

Authors: Wilson, D; Hinz, A; Goicoechea, JM

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Angewandte Chemie International Edition
• Volume: 57
• Issue: 8
• Pages: 2188–2193
• Publication date: 2018-01-08
• Acceptance date: 2018-01-08
• DOI: 10.1002/anie.201712624
• EISSN: 1521-3773
• ISSN: 1433-7851
• Pmid: 29316112
• Language: English
• Keywords: phosphalkenes; phosphorus; 1,3,2-diazaboroles; 2-phosphaethynolates; 1H-diphosphirenes