Stimulus package for organic synthesis: The economy of step and atom usage has been widely reviewed and acknowledged as being useful frameworks to evaluate the efficiency of synthesis. This Review brings to attention another form of economy which should be considered in the planning and evaluation of a multistep synthesis: redox economy. Several guidelines and examples are included to illustrate the logic of this approach and to stimulate the design of syntheses.
“Economy” is referred to as the thrifty and efficient use of material resources, as the principle of “minimum effort to reach a goal.” More illuminating is: “the aim to portion one's forces in order to use as little as possible of them to reach a goal.” Such statements certainly apply when the goal is to synthesize a complex target molecule. Redox economy then implies the use of as few redox steps as possible in the synthetic conquest of a target compound. While any sort of economy will help to streamline the effort of total synthesis, redox economy addresses a particularly weak area in present-day total synthesis. It is not enough to point out the present deficiencies, rather the purpose of this Review is to serve as a teaching tool for all practitioners of the field by giving and illustrating guidelines to increase redox economy in multistep organic synthesis.