0000000001132245
AUTHOR
Virve Karttunen
Mechanistic Studies on the Metal-Free Activation of Dihydrogen by Antiaromatic Pentarylboroles
The perfluoro- and perprotiopentaphenylboroles 1 and 2 react with dihydrogen to effect H–H bond cleavage and formation of boracyclopentene products. The mechanism of this reaction has been studied experimentally through evaluation of the kinetic properties of the slower reaction between 2 and H2. The reaction is first-order in both [borole] and [H2] with activation parameters of ΔH⧧ = 34(8) kJ/mol and ΔS⧧ = −146(25) J mol–1 K–1. A minimal kinetic isotope effect of 1.10(5) was observed, suggesting an asynchronous geometry for H–H cleavage in the rate-limiting transition state. To explain the stereochemistry of the observed products, a ring-opening/ring-closing mechanism is proposed and suppo…
Hydrogen activation with perfluorinated organoboranes: 1,2,3- tris(pentafluorophenyl)-4,5,6,7-tetrafluoro-1-boraindene
The perfluorinated boraindene 3 was synthesized and fully characterized. Both computational and crystallographic data show that 3 is antiaromatic. Compound 3 was shown to react reversibly with H2 and to catalyse the hydrogenation of cyclohexene. The mechanism of catalysis was probed experimentally and computationally. peerReviewed