N-Glycosyl-thiophene-2-carboxamides: synthesis, structure and effects on the growth of diverse cell types

Urea-catalyzed N-Glycosylation of Amides/Azacycles with Glycosyl Halides

The efficient synthesis of N-glycosides via direct N-glycosylation of amides/azacycles has been reported. The glycosylation of amides/azacycles with glycosyl halides in the presence of a catalytic amount of urea proceeded smoothly to provide the corresponding N-glycosylated amides or nucleosides in good to excellent yields with 1,2-trans-stereoselectivity. Moreover, by the addition of terpyridine, the 1,2-cis-stereoselectivity was achieved.

Accessing pyrrolones and pyridinones: controlling 5-exo and 6-endo ring closures in heterocyclic alkynylamides

Competitive 5-exo and 6-endo anionic intramolecular cyclization reactions in heterocyclic alkynylamides were explored via experimental and computational analysis. The 5-exo-dig cyclization pathway is usually disfavoured in heterocyclic systems, and 6-endo products are often both the kinetic and thermodynamic products. However, we’ve found that it is possible to shift selectivity toward the 5-exo-dig pyrrolone products away from the less strained pyridinone products that are produced via the 6-endo-dig cyclization. Parameters such as identity of heteroatom, heteroatom positioning within the heterocycle, and functionality on the alkyne were investigated and, in many cases, were found to strongly influence product ratios. A series of computational studies was performed to provide further insight into the 5-exo-dig and 6-endo-dig pathways in these heterocyclic systems. Theoretical predictions were found to reproduce experimental results, highlighting the predictive capabilities of the computations in determining preferred products.

Synthesis of N-heteroaroyl aminosaccharide derivatives as fibroblast growth factor 2 signaling modulators

Fibroblast growth factor 2 (FGF2) signaling plays an important role in angiogenesis. Heparin/heparan sulfate (HS) is required for FGF2 signaling but heparin mimics either promotes or inhibits FGF2 signaling. To take advantage such properties of heparin mimics, a series of N-heteroaroyl aminosaccharide derivatives were designed and synthesized as FGF2 signaling modulators. The bioactivity was determined in a FGF2 and heparin-dependent cell proliferation assay using FGFR1c expressing BaF3 cells. We found that most of the compounds inhibited heparin- and FGF2-dependent BaF3 cell proliferation while three compounds promoted the cell proliferation. These results suggest that the small molecular heparin mimics approach might be useful in developing novel anti-angiogenic agents.