Annulative Coupling of β-Ketosulfoxonium Ylides and β-Ketothioamides: Access to Thiazolines and Thiazolidin-4-Ones

A catalyst- and additive-free one-step protocol for synthesizing thiazolines and thiazolidin-4-ones, utilizing the annulative coupling between beta-ketosulfoxonium ylides and beta-ketothioamides has been described. The dual functionalization of beta-ketosulfoxonium ylides through S-alkylation and intramolecular N-cyclization leads to the generation of both C-S and C-N bonds. The developed synthetic methods facilitate the synthesis of diverse functionalized thiazolines and thiazolidin-4-one derivatives, validated through large-scale reactions.