Efficient and Stereoselective Synthesis of (<i>Z</i>)‐2‐Oxazolines by Transition Metal‐Free Cycloisomerization of Internal Propargylic Amides in Hexafluoroisopropanol (HFIP)

Abstract An efficient transition metal‐free protocol for the cyclization of propargylic amides with internal triple bonds to 2‐oxazolines is described. The reaction is performed in hexafluoroisopropanol (HFIP) in the presence of TMSCl which acts as a source of anhydrous HCl. The reaction conditions were optimized using response surface methodology. The oxazolines are formed stereoselectively with (Z)‐configuration of the exocyclic double bond.