Sustainability in a can: upcycling aluminium scrap in the waste-minimized electrochemical synthesis of 2-oxazoline†

Abstract

The use and consumption of electrodes is a crucial aspect regarding the overall efficiency and sustainability of electrochemical reactions. When metal electrodes are used, the cost of the material combined with the processing costs assumes relevance in terms of economics and sustainability. Herein we report a case study that aims to define an electrochemical synthetic protocol using electrodes prepared from recovered aluminium scrap. We approached the problem by evaluating and comparing the different carbon footprints associated with the use of different electrode materials from primary sources and secondary (recycled) sources. We optimized the use of electrodes made from secondary aluminium to develop a simple, oxidant-free protocol for the representative synthesis of 2-oxazolines from amino alcohols and aldehydes using generally elusive concentrated conditions and a recoverable reaction media. A further evaluation of the developed process using green metrics allowed us to quantify the waste distribution of our procedure in comparison with the literature processes as well as the progress in terms of sustainability and intrinsic reaction efficiency.