Base induced isomerisation of a phosphaethynolato-borane: mechanistic insights into boryl migration and decarbonylation to afford a triplet phosphinidene
We report on the (tert-butyl)isocyanide-catalysed isomersation of a phosphaethynolato-borane, [B]OCP ([B] = N,N′-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaboryl), to its linkage isomer, a phosphaketenyl-borane, [B]PCO. Mechanistic insight into this unusual isomerisation was gained through...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Royal Society of Chemistry
2019
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| Summary: | We report on the (tert-butyl)isocyanide-catalysed isomersation of a phosphaethynolato-borane, [B]OCP ([B] = N,N′-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaboryl), to its linkage isomer, a phosphaketenyl-borane, [B]PCO. Mechanistic insight into this unusual isomerisation was gained through a series of stoichiometric reactions of [B]OCP with isocyanides and theoretical calculations at the Density Functional Theory (DFT) level. [B]PCO decarbonylates under photolytic conditions to afford a novel boryl-substituted diphosphene, [B]P[double bond, length as m-dash]P[B]. This reaction proceeds via a transient triplet phosphinidene which we have been able to observe spectroscopically by Electron Paramagnetic Resonance (EPR) spectroscopy. |
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