A one-step method for the conversion of nitroarenes into phenols under operationally simple, transitionmetal-free conditions is described. This denitrative functionalization protocol provides a concise and economical alterna-tive to conventional three-step synthetic sequences. Experimental and computational studies suggest that nitroarenes may be substituted by an electron-catalysed radical-nucleophilic substitution (S RN 1) chain mechanism.Nitroarenes are easily prepared, abundant chemical feedstocks, and privileged synthetic intermediates in organic chemistry. [1,2] The nitro group can be converted into a large variety of functional groups through a well-established three-step sequence consisting of (1) reduction, (2) diazotization and (3) substitution through Sandmeyer-type reactions (Scheme 1a). [3] Whilst generally reliable, this approach requires multiple synthetic steps, typically involving harsh reaction conditions and the handling of hazardous intermediates. The development of more efficient, single-step denitrative functionalization reactions is therefore an area of significant synthetic value and interest. [4,5] In this regard, direct nucleophilic substitution is an attractive synthetic approach due to its low cost and operational simplicity. [6] However, these methods are typically limited to electron-deficient (activated) nitroarenes bearing strong electron-withdrawing groups in the ortho or para positions. [7] Methods which can overcome this limitation are known, but are rare and of limited scope. For example, Snyder and co-workers reported that unactivated nitroarene 1 could be substituted with oxime anion 2 to form phenol 3 in 20 % yield (Scheme 1b). [8] This denitrative hydroxylation reaction was proposed to proceed via a stepwise addition-elimination nucleophilic aromatic substitution (S N Ar) mechanism (followed by the elimination of an O-aryl oxime intermediate to form phenol 3). However, the mechanism of this reaction -along with many such denitrative substitution reactions -has long [a

A one-step method for the conversion of nitroarenes into phenols under operationally simple, transition-metal-free conditions is described. This denitrative functionalisation protocol provides a concise and economical alternative to conventional three-step synthetic sequences. Experimental and computational studies suggest that unactivated nitroarenes may be substituted via an electron-catalysed radical-nucleophilic substitution (SRN1) chain mechanism.