Reaction of -alkylthiazolium halides, including thiamine, with superoxide ion. Chemistry and biological implications.
作者:Alessandro Dondoni、Guido Galliani、Annarosa Mastellari、Alessandro Medici
DOI:10.1016/s0040-4039(00)98871-3
日期:1985.1
N-alkylthiazolium halides are transformed by KO2 into the corresponding thiazolin-2-ones and thiazolin-2-thiones; the same reactions occur with thiamine, whose thiazolin-2-one pyrophosphate has been reported to be a strong inhibitor of pyruvic dehydrogenase.
NHCs-mediated benzoates formation directly from aromatic aldehydes and alkyl halides
作者:Yi Li、Wenting Du、Wei-Ping Deng
DOI:10.1016/j.tet.2012.02.079
日期:2012.5
A NHCs-mediated benzoates formation was developed by treatment of aromatic aldehydes with alkylhalides in the presence of oxygen. Corresponding benzoate derivatives were obtained in high yields up to 99%. The reaction mechanism was also discussed and a NHCs-mediated O-alkylation and subsequent oxidation process was proposed.
The reaction of 3,3′-dimethy]-2,2′-bithiazolium salts with potassium superoxide afforded new ten-membered ring compounds 1,2,5,8-dithiadiazecin-6,7-diones in moderate yields. Since these compounds were not obtained from the reaction of KOH-O2 or KOH-H2O2, the reaction is revealed to be specific for superoxide.
3-Methylbenzothiazolium salts were allowed to react with superoxide to afford dimeric bis[o-(N-formyl-N-methylamino)phenyl]disulfides and 3-methyl-2-benzothiazolones. The reaction was applied to monocyclic thiazolium salts, and novel ten-membered ring compounds were formed whose structures were elucidated by X-ray crystallographic analysis. These results prompted us to alternative synthesis of the