A highly chemoselective consecutive cross-coupling/cyclization cascade of β-ketothioamides
with dihaloalkanes has been achieved under transition-metal free condition, enabling
the formation of methylene-functionalized thiazolidines and 1,3-thiazinanes at room
temperature in open air in high yields. The typical features of this straightforward
sustainable approach include readily accessible starting materials, simple one-pot
operation, atom-/step-economy, cost-effective, good substrate scope, and scalability.
Noteworthy, HX is the only by-product, and stereochemistry of the exocyclic methylene
moiety was assigned to have Z-configuration. Late-stage functionalization could provide
new opportunities for the discovery of N, S-heterocyclic drugs, and other potential
functional molecules.
