A facile and efficient N-to-C allyl shift-aza-Prins cyclization sequence of cyclic N-2-en-4-ynyl-N-1-ynylamides is promoted by iron(III) chloride, generating chloro-containing bridged bicyclic enamines in minutes and in high yields. This reaction involves an unprecedented formation of a ketenimine via Fe(III)-mediated N-to-C allyl rearrangement, followed by aza-Prins cyclization. This sequence can also be applied to the generation of brominated cyclobutenamine derivatives using Fe(III) bromide and N-propargyl-N-1-ynylamides. (Figure presented.).
ASJC Scopus subject areas
- Organic Chemistry