Gold-Catalysed Cycloisomerisation of Ynamides To Access 2,2-Disubstituted Tetrahydrothiophene Motifs

Ynamides bearing a tethered allyl sulfoxide undergo a gold-catalysed cycloisomerisation to afford tetrahydrothiophene-2-carboxamides and their benzo-fused analogues. The reactions are initiated by a formal 7-endo-dig cyclisation and accommodate a range of different substituents. The use of N-allyl ynamides provided a route into novel spirocyclic epsilon-lactam structures.

Automated summary

In this study, ynamides with tethered allyl sulfoxide undergo a gold-catalysed cycloisomerisation to yield tetrahydrothiophene-2-carboxamides and their benzo-fused analogues. The reactions are initiated by a formal 7-endo-dig cyclisation and can accommodate various substituents. Additionally, the use of N-allyl ynamides provides a pathway to novel spirocyclic epsilon-lactam structures.