Highly (Z)-diastereoselective approaches for the synthesis of trifluoromethylated exo-glycals by copper and photoredox catalysis are described. These complementary reactions are applicable to a wide range of methylene exo-glycals generated from the corresponding pyranoses and furanoses and give trifluoromethylated compounds under mild conditions in moderate to good yields. DFT calculations have allowed a rationalization of the observed (Z)-stereoselectivity.
Frédéric, C. J.-M., Cornil, J., Vandamme, M., Dumitrescu, L., Tikad, A., Robiette, R., & Vincent, S. P. (2018). Highly (Z)-Diastereoselective Synthesis of Trifluoromethylated exo-Glycals via Photoredox and Copper Catalysis. Organic Letters, 20(21), 6769-6773. https://doi.org/10.1021/acs.orglett.8b02891 (Original work published 2018)