Abstract / Description of output
An intramolecular 1,2-boryl-anion migration from boron to carbon has been achieved by selective activation of the π system in [(vinyl)B2Pin2)]− using “soft” BR3 electrophiles (BR3=BPh3 or 9-aryl-BBN). The soft character is key to ensure 1,2-migration proceeds instead of oxygen coordination/B−O activation. The BR3-induced 1,2-boryl-anion migration represents a triple borylation of a vinyl Grignard reagent using only B2Pin2 and BR3 and forms differentially protected 1,1,2-triborylated alkanes. Notably, by increasing the steric bulk at the β position of the vinyl Grignard reagent used to activate B2Pin2, 1,2-boryl-anion migration can be suppressed in favor of intermolecular {BPin}− transfer to BPh3, thus enabling simple access to unsymmetrical sp2−sp3 diboranes.
Original language | English |
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Pages (from-to) | 13293-13297 |
Number of pages | 5 |
Journal | Angewandte Chemie - International Edition |
Volume | 57 |
Issue number | 40 |
Early online date | 13 Aug 2018 |
DOIs | |
Publication status | E-pub ahead of print - 13 Aug 2018 |
Keywords / Materials (for Non-textual outputs)
- 1,2-migration
- boranes
- borylation
- Grignard reagents
- Lewis acids