Creative approaches towards the synthesis of 2,5-dihydro- furans, thiophenes, and pyrroles. One method does not fit all!

Abstract

A single method is never sufficient, which is why there is a great need for developing many diverse and creative approaches towards every chemical substrate class. This statement is supported by the contents of this perspective in addition to providing the reader with a helpful synthetic roadmap for selecting a suitable method for the building blocks being discussed. Detailed in this review are eight different synthetic approaches that provide access to valuable 2,5-dihydro- furan, thiophene and pyrrole building blocks. Each approach is briefly presented and its limits discussed. The strengths and weaknesses of each approach are further highlighted with a graphical table summary at the end. This summary clearly drives home the point that for every chemical substrate class we need many good methods in order to provide access to every member of each class.