Asymmetric Arylation of Secondary Alkyl Electrophiles
Stereoconvergent Negishi Arylations of Racemic Secondary Alkyl Electrophiles: Differentiating between a CF3 and an Alkyl Group.
J. Am. Chem. Soc. 2015;
18 September 2015 (online)
Enantiodivergent cross-coupling of an arylzinc reagent and a secondary alkyl halide with a trifluormethyl substituent was achieved by using a readily available nickel/bis(oxazoline) catalyst. The fluorinated products were obtained in good yields and with high enantioselectivities.
Fu and co-workers have previously reported an enantiodivergent cross-coupling of a racemic secondary electrophile by using a chiral nickel catalyst (J. Am. Chem. Soc. 2005, 127, 4594; J. Am. Chem. Soc. 2014, 136, 12161). The chiral catalyst can differentiate between a trifluoromethyl and an alkyl group to deliver the cross-coupling product with high enantioselectivity. The cross-coupling reaction is not air-sensitive, as identical results were obtained when the reaction was conducted in the presence of air.