Thioisomünchnones versus Acrylamides via Copper-Catalyzed Reaction of Thioamides with Diazocarbonyl Compounds

Reactions of Thioamides with Iminoiodinanes: An Approach toward 1,2-Thiazines, Thiophenes, and Sulfonylisothiazolines

Transition metal-catalyzed and noncatalytic reactions of acrylic thioamides with N-sulfonyliminoiodinanes enabling the selective synthesis under mild conditions of a series of fully decorated S- and N,S-containing heterocycles are described. Fine-tuning of the thioamide structure allows selective preparation in good yields of ortho-fused thiophenes, 1,2-thiazines, and spiro-fused isothiazolines. A one-pot thermally induced rearrangement of sulfonylisothiazolines was discovered as a complementary route to thiophenes.

Direct Synthesis of α-Ketothioamide Derivatives through a One-Pot Reaction of Sulfur Ylides, Nitrosobenzenes, and Thioacetic Acid

A one-pot approach has been developed for the synthesis of α-ketothioamide derivatives from sulfur ylides, nitrosobenzenes, and thioacetic acid. This protocol is carried out under mild reaction conditions in generally moderate to excellent yields without any precious catalysts, affording the derivatives with structural diversity. Additionally, a possible mechanism for this chemical transformation is proposed.

Aminoquinolones and Their Benzoquinone Dimer Hybrids as Modulators of Prion Protein Conversion

Prion Diseases or Transmissible Spongiform Encephalopathies are neurodegenerative conditions associated with a long incubation period and progressive clinical evolution, leading to death. Their pathogenesis is characterized by conformational changes of the cellular prion protein-PrP^C-in its infectious isoform-PrP^Sc-which can form polymeric aggregates that precipitate in brain tissues. Currently, there are no effective treatments for these diseases. The 2,5-diamino-1,4-benzoquinone structure is associated with an anti-prion profile and, considering the biodynamic properties associated with 4-quinolones, in this work, 6-amino-4-quinolones derivatives and their respective benzoquinone dimeric hybrids were synthesized and had their bioactive profile evaluated through their ability to prevent prion conversion. Two hybrids, namely, 2,5-dichloro-3,6-bis((3-carboxy-1-pentyl-4-quinolone-6-yl)amino)-1,4-benzoquinone (8e) and 2,5-dichloro-3,6-bis((1-benzyl-3-carboxy-4-quinolone-6-yl)amino)-1,4-benzoquinone (8f), stood out for their prion conversion inhibition ability, affecting the fibrillation process in both the kinetics-with a shortening of the lag phase-and thermodynamics and their ability to inhibit the formation of protein aggregates without significant cytotoxicity at ten micromolar.