Highly enantioselective addition of dimethylzinc to fluorinated alkyl ketones, and the mechanism behind it

Abstract

Switching the solvent from toluene to dichloromethane results in a very important enhancement in the yield and enantiomeric excess of nucleophilic addition.

A Gallium-based Chiral Solvating Agent Enables the Use of 1H NMR Spectroscopy to Differentiate Chiral Alcohols

“…Chiral alcohols can be synthesized via (1) multistep transformations from a chiral pool such as terpenes, amino acids, and carbohydrates (Fan et al., 2019, Hung et al., 2019, Brill et al., 2017) or (2) kinetic resolution of racemic alcohols or their derivatives (Liu et al., 2019, Selier et al., 2019, Zhang and Ma, 2018). In addition, asymmetric synthesis such as reduction or nucleophilic addition of prochiral carbonyls recently has been developed (Neves-Garcia et al., 2018, Tsai et al., 2018; Bieszczad and Gilheany, 2017, Nakamura et al., 2017). Although HPLC and GC with chiral stationary phases are commonly used for chiral analysis of alcohols as a reliable direct analytical technique, derivatization of alcohols such as introducing chromophores, polar functional groups, or hydrophobic units is often necessary for the desirable analytical results.…”

Visible-light-induced hydroxycarboxylation of α-trifluoromethylstyrenes to construct densely functionalized α-CF3 tertiary alcohols

“…4 Generally, the traditional method is the direct addition of nucleophiles to trifluoromethyl ketones or addition of ketones using nucleophilic trifluoromethyl reagents, but the nucleophilic addition process which is not compatible with sensitive functional groups, such as carboxyl and ester groups, limits the practical application of this method (Scheme 1b). 5 Therefore, it is of great significance to develop a mild and broadly applicable approach for the synthesis of compounds containing α-CF 3 tertiary alcohols.…”

Catalytic Asymmetric Construction of Tertiary Carbon Centers Featuring an α-Difluoromethyl Group with CF2H-CH2-NH2 as the “Building Block”

“…In those reports, aromatic groups attached to the N-end of the imine were not easily removed, hindering the further application of such blocks. When aldehydes, − ketones, − and alkenes, − carrying a difluoromethyl group, acted as CF 2 H-containing building blocks, metal catalytic conditions were normally used.…”