Functional Group Transformation in Naphthoquinones: Strategies for the Synthesis of Mono- and Bis(Amino-1,4-Naphthoquinones)

1,4-Naphthoquinones are a group of natural and synthetic substances that participate in various biochemical functions in most plants and animals, being involved in energy production, electron transport, blood coagulation, and generation of reactive oxygen species (ROS), among others. The performance of such biochemical functions is directly related to the functional groups linked to the 1,4-naphthoquinone scaffold, and the introduction of nitrogencontaining groups into this nucleus may amplify its biological activity against numerous targets. Therefore, several methods have been developed in the last decades for preparing these compounds, especially from 1,4-naphthoquinone derivatives. Considering these concepts, in this review, we aim to provide insights into the chemistry, chemical synthesis, semi-synthesis, pharmacological effects, and reactivity of low molecular weight mono- and bis(aminonaphthoquinones); we start by discussing the use of some of the most important 1,4-naphthoquinones as starting materials for the synthesis of amino-1,4-naphthoquinones (ANQs), examine the modification of ANQ derivatives, and conclude by providing an outlook on this field.