Figure 1. Ammonium-organofluorine affinity in enantioselective organoboron addition to trifluoromethylketones.
a, Effective catalytic methods for additions of allyl or allenyl units to fluorinated ketones may allow for facile synthesis of biologically active molecules and drugs such as fluralaner and BI 653048. b, Catalytic enantioselective additions of unsaturated organoboron compounds proceed with minimal enantioselectivity (unlike phosphinoyl imines or isatins). c, DFT calculations at the M06-2X or ωB97XD/6-311++G(2df,2pd)//M06-2X/6-31G(d,p)toluene(PCM) level suggest that higher enantiomeric ratio (e.r.) might be achievable with trifluoromethylketones because of a combination of different attractive and/or repulsive electrostatic forces involving a fluorine atom. Free energy values for transition states are in kcal/mol relative to the most favorable alternative. Abbreviations: G or R, a functional group; pin, pinacolato; L, ligand.
