Reactivity parameters. Part 2. The usefulness of 13C-1H one-bond coupling constants as selectivity parameters in the synthesis of organolithium compounds

Abstract

¹³ C–H One-bond coupling constants have been used as selectivity parameters for identifying the reactive positons of aromatic systems in lithiation reactions. For differencies of coupling constants >5 Hz correct predictions are always made. For differencies of 2–5 Hz correct predictions are also made, if no hetero-substituents are present. The possibility of using incorrect predictions for assignment of true ortho-directing effects of hetero-substituents due to complexing of lithium with the substituent in the transition state is discussed.