184095-69-0Relevant articles and documents
Generation of Axially Chiral Fluoroallenes through a Copper-Catalyzed Enantioselective β-Fluoride Elimination
O'Connor, Thomas J.,Mai, Binh Khanh,Nafie, Jordan,Liu, Peng,Toste, F. Dean
supporting information, p. 13759 - 13768 (2021/09/07)
Herein we report the copper-catalyzed silylation of propargylic difluorides to generate axially chiral, tetrasubstituted monofluoroallenes in both good yields (27 examples >80%) and enantioselectivities (82-98% ee). Compared to previously reported synthetic routes to axially chiral allenes (ACAs) from prochiral substrates, a mechanistically distinct reaction has been developed: the enantiodiscrimination between enantiotopic fluorides to set an axial stereocenter. DFT calculations and vibrational circular dichroism (VCD) suggest that β-fluoride elimination from an alkenyl copper intermediate likely proceeds through a syn-β-fluoride elimination pathway rather than an anti-elimination pathway. The effects of the C1-symmetric Josiphos-derived ligand on reactivity and enantioselectivity were investigated. Not only does this report showcase that alkenyl copper species (like their alkyl counterparts) can undergo β-fluoride elimination, but this elimination can be achieved in an enantioselective fashion.
Synthesis method of Josiphos chiral ferrocenyl phosphine ligands
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Paragraph 0007; 0059; 0060, (2017/05/27)
The invention discloses a synthesis method of Josiphos chiral ferrocenyl phosphine ligands, and belongs to the field of organic synthesis. The method is realized through the following steps of using ferrocene as a starting raw material; using aluminum chloride as a catalyst; taking a reaction with phosphonic chloride compound R2PCl; then, taking a reaction with vinyl diaryl phosphine under the catalysis effect of ferric trichloride and D-proline to obtain the Josiphos chiral ferrocenyl phosphine ligands. Compared with the prior art, the synthesis method has the advantages that the steps are few; the operation is simple; the production cost is reduced; the synthesis method is suitable for industrial production. The prepared Josiphos chiral ferrocenyl phosphine ligands can be used as ligands of metal catalysts for catalyzing an unsymmetrical organic reaction; the synthesis method is applied to the fields of medicine synthesis and the like.
