Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• thiobenzamides [26][27]. The latter authors concluded that the relative occurrence of 1,2,4-thiadiazoles (XV) during the Hantzsch reaction probably depends on the steric demands of the starting α-haloketones/esters II, but the real explanation is probably more complicated. Therefore, we have decided to examine

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• drugs. The Yadav research group have also published the homocoupling of primary thioamides for the formation of symmetrical 1,2,4-thiadiazoles, using visible light and Eosin Y as the photocatalyst, in air at room temperature (Scheme 19) [64]. The immediately obvious limitation of this reaction is the

A one-pot multistep cyclization yielding thiadiazoloimidazole derivatives

• Debabrata Samanta,
• Anup Rana,
• Jan W. Bats and
• Michael Schmittel

Beilstein J. Org. Chem. 2014, 10, 2989–2996, doi:10.3762/bjoc.10.317

• Main, Germany 10.3762/bjoc.10.317 Abstract A versatile synthetic procedure is described to prepare the benzimidazole-fused 1,2,4-thiadiazoles 2a–c via a methanesulfonyl chloride initiated multistep cyclization involving the intramolecular reaction of an in-situ generated carbodiimide with a thiourea

• unit. The structure of the intricate heterocycle 2a was confirmed by single-crystal X-ray analysis and its mechanism of formation supported by DFT computations. Keywords: carbodiimide; cyclization; dithiourea; DFT; 1,2,4-thiadiazoles; Introduction Heterocyclic rings are key components in many

• bioactive compounds. For instance, thiadiazole containing heterocycles are known to exhibit important anti-inflammatory, antihypertensive, anti-HIV and antituberculosis activity [1]. Within this family, 1,2,4-thiadiazoles display notable medicinal properties as potent neuroprotectors [2