Polarisation by cation formation: a method for influencing the selectivity of radical chlorination

Abstract

Polarisation by cation formation (e.g., by protonation or by oxocarbonium ion formation) exerts a distinct and systematic effect on the selectivity of radical chlorination of aliphatic acids, amines, and alcohols. A qualitative correlation is demonstrated between the magnitude of deshielding of a given proton (as expressed by the downfield shift in the ¹H n.m.r. spectrum) and its “deactivation” as indicated by diminished rate of its abstraction by chlorine atoms. A convenient method is described for the preparation of new and known aliphatic mono- and polychloro-amines.