Versatile Protecting-Group Free Tetrazolomethane Amine Synthesis by Ugi Reaction

The use of ammonia in the Ugi reaction is often problematic due to low yields and multiple side reactions. Here, we report the use of ammonia in the tetrazole Ugi variation providing a clean, good-to-high yielding reaction, especially with ketones as oxo components. The scope and limitations of this reaction and a structure-reactivity relationship are provided by performing >85 reactions. The primary amine component of the α-amino tetrazole is a versatile starting material for further reactions.