Abstract
Alkenyl boronic esters are important reagents in organic synthesis. Herein, we report that these valuable products can be accessed by the homologation of boronic esters with lithiated epoxysilanes. Aliphatic and electron-rich aromatic boronic esters provided vinylidene boronic esters in moderate to high yields, while electron-deficient aromatic and vinyl boronic esters were found to give the corresponding vinyl silane products. Through DFT calculations, this divergence in mechanistic pathway has been rationalized by considering the stabilization of negative charge in the C-Si and C-B bond breaking transition states. This vinylidene homologation was used in a short six-step stereoselective synthesis of the proposed structure of machillene, however, synthetic and reported data were found to be inconsistent.
Original language | English |
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Pages (from-to) | 15268-15272 |
Number of pages | 5 |
Journal | Angewandte Chemie-International Edition |
Volume | 58 |
Issue number | 43 |
Early online date | 31 Jul 2019 |
DOIs | |
Publication status | Published - 21 Oct 2019 |
Keywords
- homologation
- natural product
- organoboron
- stereospecificity
- vinyl boronic ester
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)