The first ionic liquid-promoted one-pot diastereoselective synthesis of 2,5-diamino-/2-amino-5-mercapto-1,3-thiazin-4-ones using masked amino/mercapto acids

The Biginelli Reaction with an Imidazolium–Tagged Recyclable Iron Catalyst: Kinetics, Mechanism, and Antitumoral Activity

“…The Brønsted acid in the cation structure of MAI is responsible for the aldehyde carbonyl activation, similar to the mechanism by using 1-butyl-3-methylimidazolium derivatives as first proposed by the group of Dupont, [36] and followed by Yadav [37] and Raval. [38] The anion Fe 2 Cl 7 À , a strong Lewis acid, is responsible for the in situ formation of the nucleophilic complex FeA C H T U N G T R E N N U N G (acac) 3 , which in turn reacts with the iminium intermediate.…”

Ionic Liquids-Prompted Synthesis of Biologically Relevant Five- and Six-Membered Heterocyclic Skeletons

“…In order to investigate the substrate scope of the reaction, a variety of aromatic aldehydes and thioureas were used, and afforded good yield of products with trans-diastereoselectivity. In solvent optimization studies, acetonitrile demonstrated best yield and diastereoselectivity over the THF, CH 2 Cl 2 , and MeOH [279]. The optimum catalyst loading for [BMIM][Br] was found to be 20 mol%.…”

Bioactive Thiazine and Benzothiazine Derivatives: Green Synthesis Methods and Their Medicinal Importance

“…Yadav et al developed a new, expeditious, three-component method for the synthesis of 3,6-diaryl-5-mercaptoperhydro-2-thioxo-1,3-thiazin-5-ones 1,3-thiazine analogues from 2-methyl-2-phenyl-1,3-oxathiolan-5-one under solvent-free conditions [19]. They synthesized 2-methyl-2-phenyl-1,3-oxathiolan-5-one [20] from 2-mercaptoacetic acid and acetophenone using lithium bromide as a catalyst [19]. This intermediate was treated with a benzaldehyde and N -aryldithio carbamic acid to synthesize the desired product in a one-pot synthesis method using microwaves [19].…”

“…This intermediate was treated with a benzaldehyde and N -aryldithio carbamic acid to synthesize the desired product in a one-pot synthesis method using microwaves [19]. It is diastereoselective process and involves tandem Knoevenagel, Michael and ring transformation steps, as presented in Scheme 8 [19,20].…”

“…Therefore, novel strategies are being devised to generate future generation cephalosporins [38]. In addition to broad spectrum activities, 1,3-thiazine and its derivatives contains wonderful properties like antitumor, insecticide, and fungicidal [19,20,40,41]. Further, these can be used as anti-radiation agents in radiation-sickness [19,20,40,41].…”