Ascorbic Acid: An Efficient Organocatalyst for the Synthesis of 2‐Amino‐1,3,4‐oxadiazoles and Thiadiazoles via C−X Bond Formation.

A new protocol for the synthesis of 2‐amino‐substituted 1,3,4‐oxadiazoles and 1,3,4‐thiadiazoles, were developed using semicarbazide or thiosemicarbazide along with the various aldehydes, followed by C−X (X=O, S) bond formation using ascorbic acid as a catalyst. This rapid, efficient, accessible, and robust/scalable sequential synthesis works with aromatic, aliphatic, and cinnamic aldehydes to provide a wide range of diazole derivatives with a 2‐amino substituent without the use of any transition metals. The synthesised molecules were characterised by 1H and 13C NMR analysis. [ABSTRACT FROM AUTHOR]