A.S. Pankova, A.Yu. Stukalov, M.A. Kuznetsov
“Synthesis of 2‑(Hetero)aryl-5-(trimethylsilylethynyl)oxazoles from 2 (Hetero)arylacrylic Acids”
Org. Lett., 2015, accepted
A three-step method for the synthesis of 2-(hetero)-aryl-5-(trimethylsilylethynyl)oxazoles is described. Easily accessible bis(trimethylsilyl)acetylene and acrylic acid derivatives are used as starting materials for the preparation of mono- and disubstituted 5-(trimethylsilyl)pent-1-en-4-yn-3-ones. Oxidative phthalimido-aziridination of these enynones provides the key 2-acyl-1-phthalimido-aziridines that are further utilized in the thermal expansion of the three-membered ring to furnish the target functionalizable oxazoles.