N-Haloimide-enabled halogenation via halogen-bond-assisted C–C activation of alkanols

Abstract

The selective halogenation of the inert C–C bonds of alcohol-based feedstock is of tremendous significance in synthetic chemistry. Previous halogenation usually requires a metal catalyst and/or an oxidant and is limited to the cleavage of the C–C bonds of tertiary cycloalkanols. Herein, we report a broadly applicable strategy for the synthesis of iodoalkanes, bromoalkanes and chloroalkanes via the halogen-bond-assisted C–C activation of cyclic and acyclic alkanols in the absence of catalysts and oxidants, where the inexpensive N-haloimides act as bifunctional reagents to activate and halogenate alcohols. This redox-neutral protocol is a general method for the halogenation of the C–C bonds of primary, secondary, and tertiary alkanols, thus installing three types of halogen atoms and boronic esters through one-pot deiodination–borylation in a wide range of feedstock chemicals in a practical and sustainable fashion.