Direct ortho‐Selective Amination of Naphthols with Nitroarenes through Transfer‐Hydrogenation

An efficient transition-metal free synthesis of ortho-arylaminonaphthols from nitroarenes has been developed for the first time using alcohols or ethers as a hydrogen donor.

Abstract

Hydrogen atom transfer from commonly used solvents to nitroarenes occurred. Such solvents required C(sp³)H-C(sp³)H bond adjacent to oxygen atoms, such as 1,4-dioxane, tetrahydrofuran, alkanol, ethylene glycol, glycerol and bis(2-methoxyethyl) ether. The transformation was transition-metal free and the reduced nitroarenes were trapped by naphthols and their analogues at ortho-position. The protocol provided a favourable and efficient route to access ortho-arylaminonaphthols and a possible mechanism is depicted.