B–B vs. B–H Bond Activation in a (μ-Hydrido)diborane(4) Anion upon Cycloaddition with CO₂, Isocyanates, or Carbodiimides
- The intriguing (μ-hydrido)diboranes(4) with their prominent pristine representative [B2H5]− have mainly been studied theoretically. We now describe the behavior of the planarized tetraaryl (μ-hydrido)diborane(4) anion [1H]− in cycloaddition reactions with the homologous series of heterocumulenes CO2, iPrNCO, and iPrNCNiPr. We show that a C=O bond of CO2 selectively activates the B−B bond of [1H]−, while the μ-H ligand is left untouched ([2H]−). The carbodiimide iPrNCNiPr, in contrast, neglects the B−B bond and rather adds the B-bonded H− ion to its central C atom to generate a formamidinate bridge across the B2 pair ([3]−). As a hybrid, the isocyanate iPrNCO combines the reactivity patterns of both its congeners and gives two products: one of them ([4H]−) is related to [2H]−, the other ([5]−) is an analog of [3]−. We finally propose a mechanistic scenario that rationalizes the individual reaction outcomes and combines them to a coherent picture of B–B vs. B–H bond activation.
Author: | Timo TrageserGND, Dariusz Bebej, Michael BolteORCiD, Hans-Wolfram LernerORCiDGND, Matthias WagnerORCiD |
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URN: | urn:nbn:de:hebis:30:3-638835 |
DOI: | https://doi.org/10.1002/anie.202103427 |
ISSN: | 1521-3773 |
Parent Title (German): | Angewandte Chemie |
Publisher: | Wiley-VCH |
Place of publication: | Weinheim |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2021/03/19 |
Date of first Publication: | 2021/03/19 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2022/03/16 |
Tag: | B−B bonds; B−H bonds; bond activation; cycloaddition; diboranes |
Volume: | 60 |
Issue: | 24 |
Page Number: | 7 |
First Page: | 13500 |
Last Page: | 13506 |
Note: | T.T. thanks the Fonds der Chemischen Industrie for a Ph.D. grant. Open access funding enabled and organized by Projekt DEAL. |
HeBIS-PPN: | 493369309 |
Institutes: | Biochemie, Chemie und Pharmazie |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Sammlungen: | Universitätspublikationen |
Licence (German): | Creative Commons - Namensnennung-Nicht kommerziell - Keine Bearbeitung 4.0 |