Solid‐Phase Synthesis of Guanidinium Derivatives from Thiourea and Isothiourea Functionalities

Guanidinium‐based compounds are biologically, medicinally, and pharmaceutically vital molecules. Due to their ability to form H‐bond interactions, charge pairing, and cation‐π interactions, guanidinium groups also perform key roles in supramolecular chemistry. They are found in nature in numerous forms and can be synthesized using different methods. Solid‐phase synthesis permits the preparation of synthetically challenging molecules and can be used for the synthesis of combinatorial libraries of lead molecules. A brief survey of methods for the synthesis of guanidiniums from thiourea and isothiourea using different reagents is discussed. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)