Assigning the Absolute Configurations of Chiral Primary Amines Based on Experimental and DFT-Calculated ¹⁹F Nuclear Magnetic Resonance.

ABSTRACT: In this work, a novel method for assigning the absolute configuration of a chiral primary amine has been developed based on the experimental and DFT-calculated ¹⁹F NMR chemical shift differences of its derived two fluorinated amides by reacting with two enantiomers of a chiral derivatizing agent FPP (α-fluorinated phenylacetic phenylselenoester) separately. Comparing the experimental chemical shift difference Δ δ α - F R , S of (R)-FPA-amide/(S)-FPA-amide with the calculated Δδ_{α-F ^R,S} of (R)-FPA-(R)-amide/(S)-FPA-(R)-amide, if the experimental Δδ_{α-F ^R,S} has the same symbol (positive or negative) as one of the theoretical Δδ_{α-F ^R,S} , the assigned configuration of the amine is considered to be consistent with the theoretical one. Our method could be applied to a broad substrate scope avoiding wrong conclusion due to empirical judgment.

SUBMITTER: Yang S 

PROVIDER: S-EPMC6536038 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature