Base induced isomerisation of a phosphaethynolato-borane: mechanistic insights into boryl migration and decarbonylation to afford a triplet phosphinidene. Issue 3 (9th December 2019)

• Record Type: Journal Article
• Authors: Wilson, Daniel W. N.; Franco, Mauricio P.; Myers, William K.; McGrady, John E.; Goicoechea, Jose M.
• Is Part Of: Chemical science. Volume 11:Issue 3(2020)
• Page Start: 862
• Page End: 869
• Publication Date: 2019-12-09
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9sc05969e
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : We report on the ( tert -butyl)isocyanide-catalysed isomersation of a phosphaethynolato-borane, [B]OCP, to its linkage isomer, a phosphaketenyl-borane, [B]PCO. Abstract : 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-1 H -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P[B]. This reaction proceeds via a transient triplet phosphinidene which we have been able to observe spectroscopically by Electron Paramagnetic Resonance (EPR) spectroscopy.