Iron Catalysis in Organic Synthesis – A Critical Assessment of What it Takes To Make This Base Metal a Multitasking Champion

Industrial homogeneous catalytic processes are dominated by the use of expensive precious metals and rely on very efficient catalytic cycles for their cost effectiveness. Many of the processes carried out with precious metals are also achieved by iron catalysis, but often other processes compete and these chemistries have not been so widely used in industry, despite the cost and environmental advantages of iron as a metal. This timely review from Alois Furstner at the Max Planck Institute in Mulheim, Germany ( ACS Central Science,  DOI 10.1021/acscentsci.6b00272) examines the fundamental reasons why iron has not achieved its potential in organic synthesis, particularly in industry and why a versatile metal, whose oxidation state can vary from –II to +VI is not more widely used, and thus can be a reductant and an oxidant is not more widely used. He provides some examples of potential uses and offers some suggestions on how control of the oxidation state, and of competing single electron transfer processes might be achieved in the future.