isocyanides, rate of addition of isocyanide to reaction mixture dictates good yields and high selectivities. Applications Apart from forming α-acyloxy amide products, the Passerini reaction can be used to form heterocycles, polymers, amino acids, and medicinal products. Heterocycles The original Passerini reaction produces acyclic depsipeptides which are labile in physiological conditions. To increase product stability for medicinal use, post-Passerini cyclization reactions have been used to afford heterocycles such as β-lactams, butenolides, and isocoumarins. To enable these cyclizations, reagents are pre-functionalized with reactive groups (ex. halogens, azides, etc.) and used in tandem with other reactions (ex. Passerini-Knoevenagel, Passerini-Dieckmann) to afford heterocyclic products. Compounds like three membered oxirane and aziridine derivatives, four-membered b-lactams, and five-membered tetrasubstituted 4,5-dihydropyrazoles have been produced through this reaction. Polymers This reaction has also been used for polymerization, monomer formation, and post-polymerization modification. The Passerini reaction has also been used to form sequence-defined polymers. Bifunctional substrates can be used to undergo post-polymerization modification or serve as precursors for polymerization. As this reaction has high functional group tolerance, the polymers created using this reaction are widely diverse with tuneable properties. Macromolecules that have been produced with this reaction include macroamides, macrocyclic depsipeptides, three-component dendrimers and three-armed star branched mesogen core molecules. Amino acids and pharmaceuticals Passerini reaction has been employed for the formation of structures like α-amino acids, α-hydroxy-β-amino acids, α-ketoamides, β-ketoamides, α-hydroxyketones and α-aminoxyamides. The Passerini reaction has synthesized α-Acyloxy carboxamides that have demonstrated activity as anti-cancer medications along with functionalized [C60]-fullerenes used in medicinal and plant chemistry. This reaction has also been used as a synthetic step in the total synthesis of commercially available pharmaceuticals such as telaprevir (VX-950), an antiviral sold by Vertex Pharmaceuticals and Johnson & Johnson. See also Ugi reaction References Carbon-carbon bond forming reactions Multiple component reactions Name reactions Amide synthesis reactions