Guanylguanidines: Catalyst and Ligand for Organic Transformations

Guanylguanidines are well known for their wide range of therapeutic applications such as antidiabetic, anticancer, antifilarial, antitrypanosomal, antiaging, etc. Apart from this, they have been explored in the field of crystal engineering, organic synthesis as substrate, non‐linear optics etc. Their metal complexation ability and superbasic nature has paved their way in the field of organocatalysis. In the recent past, various guanylguanidine derivatives have been synthesized and have proven to be excellent catalysts in several organic reactions which include transesterification, C−C and C−N coupling, oxidation, reduction, Beckmann rearrangement etc. However, the limited studies call for more focused research in this direction to fasten the process of development of environmental‐friendly methods. In this review, a comprehensive and systematic discussion of guanylguanidine based catalysts and their applications in various organotransformations has been compiled and discussed meticulously. This review aims to highlight guanylguanidine moiety as a potential catalyst that can be utilized for design and development of novel guanylguanidine based catalysts. The magical superbasic biguanide has proven to exhibit excellent catalytic properties which help in catalyzing various organic transformations such as transesterification, C−C and C−N coupling, oxidation, reduction, Beckmann rearrangement etc.