Preliminary Studies on the Transformation of Nitrosugars into Branched Chain Iminosugars: Synthesis of 1,4-Dideoxy-4-C-hydroxymethyl- 1,4-imino-pentanols

Reactivities of cyclonickellated complexes with hydroxylamines: formation of κO-hydroxylamine and κN-imine adducts and a κO, κN-aminoxide derivative

This report discusses the reactivities of hydroxylamines with a family of nickellacyclic complexes prepared by C-H nickellation of aryl phosphinites. Treating the dimeric complexes κ^C,κ^P-{2-OPR₂,4-R'-C₆H₄}₂Ni₂(μ-Br)₂ (R = i-Pr; R' = H, Cl, OMe, NMe₂) or their monomeric acetonitrile adducts κ^C,κ^P-{2-OPR₂,4-R'-C₆H₄}Ni(Br)(NCMe) with hydroxylamines showed three types of reactivities depending on the Ni complex, the reaction solvent, and the substrate used: (1) the benzyl-protected substrate PhCH₂ONH₂ gave simple N-bound adducts with all Ni complexes; (2) the parent Ni dimer (R' = H) reacted with Et₂NOH and (PhCH₂)₂NOH in CH₂Cl₂ to give, respectively, the zwitterionic amine oxide κ^C,κ^P-{2-OPR₂-C₆H₅}Ni(κ^O-ONHEt₂)Br and the bidentate aminoxide (i-R₂POPh)Ni{κ^O,κ^N-ON(CH₂Ph)₂}Br; (3) the analogous reaction of substituted Ni complexes (R' = Cl, OMe, NMe₂) with hydroxylamines in acetonitrile gave adducts of imines derived from dehydration of Et₂NOH and (PhCH₂)₂NOH. The latter reactivity proceeds optimally in acetonitrile, but it also occurs to a lesser extent in C₆D₆ if the reaction is allowed to go for more than 24 h. Different mechanistic scenarios have been considered to rationalize the observed hydroxylamine → imine transformation.

Azetidine- and N-carboxylic azetidine-iminosugars as amyloglucosidase inhibitors: synthesis, glycosidase inhibitory activity and molecular docking studies

Azetidine and an unprecedented N-carboxylic azetidine iminosugars were synthesized from d-glucose, which showed prominent amyloglucosidase inhibitory activity.

C-branched iminosugars: α-glucosidase inhibition by enantiomers of isoDMDP, isoDGDP, and isoDAB-L-isoDMDP compared to miglitol and miglustat

The Ho crossed aldol condensation provides access to a series of carbon branched iminosugars as exemplified by the synthesis of enantiomeric pairs of isoDMDP, isoDGDP, and isoDAB, allowing comparison of their biological activities with three linear isomeric natural products DMDP, DGDP, and DAB and their enantiomers. L-IsoDMDP [(2S,3S,4R)-2,4-bis(hydroxymethyl)pyrrolidine-3,4-diol], prepared in 11 steps in an overall yield of 45% from d-lyxonolactone, is a potent specific competitive inhibitor of gut disaccharidases [K(i) 0.081 μM for rat intestinal maltase] and is more effective in the suppression of hyperglycaemia in a maltose loading test than miglitol, a drug presently used in the treatment of late onset diabetes. The partial rescue of the defective F508del-CFTR function in CF-KM4 cells by L-isoDMDP is compared with miglustat and isoLAB in an approach to the treatment of cystic fibrosis.