Efficient synthesis of conformationally constrained, amino-triazoloazepinone-containing di- and tripeptides via a one-pot Ugi-Huisgen tandem reaction.

Herein we describe a catalyst-free procedure employing an Ugi-4CR between a β-azido-α-amino acid, propargylamine, an isocyanide and an aldehyde, followed by a thermal azide-alkyne Huisgen cycloaddition to generate a 16-member library of amino-triazoloazepinone-bearing di- and tripeptides with up to four points of diversification and high atom economy.