On January 1, 2017, Talsi, Evgenii P.; Bryliakov, Konstantin P. published an article.Category: imidazoles-derivatives The title of the article was Ti-Salan catalyzed asymmetric sulfoxidation of pyridylmethylthiobenzimidazoles to optically pure proton pump inhibitors. And the article contained the following:
The asym. sulfoxidation of two pyridylmethylthiobenzimidazoles to anti-ulcer drugs of the PPI family (S)-omeprazole and (R)-lansoprazole with hydrogen peroxide, mediated by a series of chiral titanium(IV) salan complexes was reported. High sulfoxide yields (up to >95%) and enantioselectivities (up to 94% ee) were achieved. The introduction of electron-withdrawing substituents leaded to less active and less enantioselective catalysts. Like for the previously reported Ti-salalen catalyzed sulfoxidations, the temperature dependence of the sulfoxidation enantioselectivity in the presence of Ti-salan complexes was nonmonotonic, demonstrating isoinversion behavior with decreasing temperature The oxidation was likely rate-limited by the formation of the active (presumably peroxotitanium(IV)) species, followed by a faster oxygen transfer to the substrate. The experimental process involved the reaction of 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]benzimidazole(cas: 73590-85-9).Category: imidazoles-derivatives
The Article related to titanium salan complex catalyst preparation, pyridylmethylthiobenzimidazole titanium salan complex catalyst sulfoxidation, pyridylmethyl benzimidazolyl sulfoxide preparation chemoselective enantioselective green chem and other aspects.Category: imidazoles-derivatives
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem