Active methylenes in the synthesis of a pyrrole motif: an imperative structural unit of pharmaceuticals, natural products and optoelectronic materials

Pyrrole is one of the most important azaheterocycles, due to its wide range of applications in pharmaceuticals and optoelectronic materials, coupled with its utility as an intermediate in natural products. For several decades, realisation of the scope and potential of this heterocyclic system in both the pharmaceutical and materials industries, has sparked new efforts in finding more efficient synthetic methods for the preparation of pyrrole compounds. Inspired by the importance of this system, herein, we report a review on pyrrole based pharmaceuticals, natural products and optoelectronic materials. Synthetic approaches to pyrrole from active methylenes are also reviewed together with novel reports from our laboratory recently (till 2015).