Facile regiodivergent synthesis of spiro pyrrole-substituted pseudothiohydantoins and thiohydantoins via reaction of [e]-fused 1H-pyrrole-2,3-diones with thiourea

• Aleksandr I. Kobelev,
• Nikita A. Tretyakov,
• Ekaterina E. Stepanova,
• Maksim V. Dmitriev,
• Michael Rubin and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2019, 15, 2864–2871, doi:10.3762/bjoc.15.280

• biological evaluation, while their medicinal chemistry properties dramatically depend on the structure of the five-membered heterocyclic moiety and substituents in the C-5 position [7]. Some pseudothiohydantoins (2-iminothiazolidin-4-ones) are known to undergo a pseudothiohydantoin–thiohydantoin

A facile, rapid, one-pot regio/stereoselective synthesis of 2-iminothiazolidin-4-ones under solvent/scavenger-free conditions

• Murugan Sathishkumar,
• Sangaraiah Nagarajan,
• Poovan Shanmugavelan,
• Murugan Dinesh and
• Alagusundaram Ponnuswamy

Beilstein J. Org. Chem. 2013, 9, 689–697, doi:10.3762/bjoc.9.78

• protocol for the synthesis of 2-iminothiazolidin-4-ones has been developed. Interestingly, the regio/stereoselective synthesis affords the regioisomeric (Z)-3-alkyl/aryl-2-(2-phenylcyclohex-2-enylimino)thiazolidin-4-one as the sole product in good yield. The selectivities observed have been rationalized

• based on the relative magnitude of the allylic strains developed during the course of the reaction. This is the first report wherein the impact of allylic strains in directing the regiocyclization has been noted. Keywords: 2-iminothiazolidin-4-ones; regioselective; stereoselective; solvent-free

• ; scavenger-free; Introduction Thiazolidin-4-one derivatives are well known for their bioactivities such as antidiabetic [1], anticancer [2], calcium-channel blocker [3][4], platelet activating factor (PAF) antagonist [5] and anti-HIV [6] activity. In addition, 2-iminothiazolidin-4-ones exhibit remarkable