2 results
Search Results
Now showing 1 - 2 of 2
- ItemDehydropolymerisation of Methylamine Borane and an N-Substituted Primary Amine Borane Using a PNP Fe Catalyst(Weinheim : Wiley-VCH, 2020) Anke, Felix; Boye, Susanne; Spannenberg, Anke; Lederer, Albena; Heller, Detlef; Beweries, TorstenDehydropolymerisation of methylamine borane (H3B⋅NMeH2) using the well-known iron amido complex [(PNP)Fe(H)(CO)] (PNP=N(CH2CH2PiPr2)2) (1) gives poly(aminoborane)s by a chain-growth mechanism. In toluene, rapid dehydrogenation of H3B⋅NMeH2 following first-order behaviour as a limiting case of a more general underlying Michaelis–Menten kinetics is observed, forming aminoborane H2B=NMeH, which selectively couples to give high-molecular-weight poly(aminoborane)s (H2BNMeH)n and only traces of borazine (HBNMe)3 by depolymerisation after full conversion. Based on a series of comparative experiments using structurally related Fe catalysts and dimethylamine borane (H3B⋅NMe2H) polymer formation is proposed to occur by nucleophilic chain growth as reported earlier computationally and experimentally. A silyl functionalised primary borane H3B⋅N(CH2SiMe3)H2 was studied in homo- and co-dehydropolymerisation reactions to give the first examples for Si containing poly(aminoborane)s. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
- ItemCatalyst Deactivation During Rhodium Complex-Catalyzed Propargylic C-H Activation(Weinheim : Wiley-VCH, 2021) Möller, Saskia; Jannsen, Nora; Rüger, Julia; Drexler, Hans-Joachim; Horstmann, Moritz; Bauer, Felix; Breit, Bernhard; Heller, DetlefDetailed mechanistic investigations on our previously reported synthesis of branched allylic esters by the rhodium complex-catalyzed propargylic C−H activation have been carried out. Based on initial mechanistic studies, we present herein more detailed investigations of the reaction mechanism. For this, various analytical (NMR, X-ray crystal structure analysis, Raman) and kinetic methods were used to characterize the formation of intermediates under the reaction conditions. The knowledge obtained by this was used to further optimize the previous conditions and generate a more active catalytic system. © 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.