Catalytic Asymmetric Conjugate Addition and Sulfenylation of Diarylthiazolidin-2,4-diones

This
work reports the first application of diarylthiazolidin-2,4-diones
as nucleophiles in asymmetric catalysis. By utilizing chiral amino
acid-based (thio)­urea–tertiary amines as the catalysts, we
successively established asymmetric conjugate addition to nitroolefins
and sulfenylation to N-(sulfanyl)-succinimides of
diarylthiazolidin-2,4-diones. Two series of biologically important
5-aryl-5-substituted thiazolidin-2,4-diones were obtained with high
enantio- and diastereoselectivities (up to >99% ee and >19:1
dr).
The enantioenriched adducts were found to show satisfactory anticancer
activities against three different cancer cell lines using the MTT
assay. All of these successes depended on the development of a general
and expedient synthetic strategy to provide diverse 5H-thiazolidin-2,4-diones.