Ammonia-promoted one-pot tetrazolopiperidinone synthesis by Ugi reaction

Ammonia in the tetrazole Ugi variation together with α-amino acid methyl ester-derived isocyanides provides tetrazolopiperidinones in good to high yields in one pot. The scope and limitations of this reaction were investigated by performing >70 reactions. The scaffold is useful to fill high-throughput screening decks and in structure-based drug design.