Back to Search
Start Over
Stereoselectivity control in Rh-catalyzed β-OH elimination for chiral allene formation
- Source :
- Nature Communications, Vol 14, Iss 1, Pp 1-13 (2023)
- Publication Year :
- 2023
- Publisher :
- Nature Portfolio, 2023.
-
Abstract
- Abstract Stereoselectivity control and understanding in the metal-catalyzed reactions are fundamental issues in catalysis. Here we report sterically controlled rhodium-catalyzed SN2’-type substitution reactions of optically active tertiary propargylic alcohols with arylmetallic species affording the non-readily available enantioenriched tetrasubstituted allenes via either exclusive syn- or anti-β-OH elimination, respectively, under two sets of different reaction parameters. Detailed mechanistic experiments and density functional theory (DFT) studies reveal that the exclusive anti-Rh(I)-OH elimination is dictated by the simultaneous aid of in situ generated boric acid and ambient water, which act as the shuttle in the hydroxy relay to facilitate the Rh(I)-OH elimination process via a unique ten-membered cyclic transition state (anti-TS2_u). By contrast, the syn-Rh(III)-OH elimination in C–H bond activation-based allenylation reaction is controlled by a four-membered cyclic transition state (syn- TS3) due to the steric surroundings around the Rh(III) center preventing the approach of the other assisting molecules. Under the guidance of these mechanistic understandings, a stereodivergent protocol to construct the enantiomer of optically active tetrasubstituted allenes from the same starting materials is successfully developed.
- Subjects :
- Science
Subjects
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 14
- Issue :
- 1
- Database :
- Directory of Open Access Journals
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.41b6a5dbfb9c41c98a2e247885fa4091
- Document Type :
- article
- Full Text :
- https://doi.org/10.1038/s41467-023-42660-1