The Versatile Test Reactor Project: Mission, Requirements, and Description
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Roglans-Ribas, Jordi↗
Engineering topics
O’Connor, Thomas J.
Publications and source records attributed to O’Connor, Thomas J..
Generation of Axially Chiral Fluoroallenes through a Copper-Catalyzed Enantioselective β-Fluoride Elimination
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.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗