Differential reactivity of fluorinated homopropargylic amino esters vs gold(I) salts. The role of the nitrogen protecting group

• A tandem hydroarylation–isomerization catalysed by gold salts is described.
• A small family of new fluorinated dihydroquinolines are obtained.
• Substrates bearing carbamates undergo cyclization rendering oxazines.
• Those compounds contain an alfa-amino acid unit.
• Differential reactivity was observed depending on the nitrogen substitution.

The reaction of several homopropargyl amino esters 4, bearing aromatic substituents and a benzyl group as nitrogen substituents, with gold(I) salts gave rise to fluorinated quinolines 6 in a tandem hydroarylation–isomerization process. On the other hand, homopropargyl amino esters 7 containing a carbamate group underwent the carbonyl addition over the triple bond in the presence of gold(I) salts, rendering fluorinated oxazines 8. The use of chiral sulfoxides allowed us to develop the asymmetric version of this protocol. This two processes complete the differential reactivity showed by these types of susbtrates, depending on the nature of the nitrogen protecting group.

A small family of new fluorinated dihydroquinolines and oxazines have been prepared by reaction of several homopropargyl amino esters with gold(I) salts. A differential reactivity was observed depending on the nature of the nitrogen protecting group.Figure optionsDownload as PowerPoint slide