Ionic liquid-assisted catalysis for glycosidation of two triterpenoid sapogenins

Abstract

In order to study the universality of ionic liquids-assisted glycosidation and explore their catalytic behaviors together with potential, oleanolic acid and ursolic acid were selected to establish catalytic system as typical triterpene sapogenins.

VaporSPOT: Parallel Synthesis of Oligosaccharides on Membranes

“…For successful glycosylations, two main parameters had to be optimized: the temperature inside the glycosylation chamber and the amount and concentration of the activator solution to be delivered. Both affect the reactivity of the building blocks and the yield. − For the preparation of different oligosaccharides, 14 building blocks (BBs, Figure ) were either synthesized following established protocols ,− or prepared from commercially available precursors (trichloroacetimidates 3 , 5 , and 9 and phosphates 6 and 8 , see Section B in the Supporting Information). To optimize the coupling conditions, glycosyl donors 1 – 6 and 8 – 12 were screened, using 8% TMSOTf in dichloromethane (Figure A), to furnish the corresponding dimers 15 – 17 in different yields (Figure B).…”

Synthesis, Characterization and Optimization of Oleyl Oleate Wax Ester Using Ionic Liquid Catalysts

“…The most important peak in the 1 H-NMR spectrum of the compound MIM-PS is the triplet peak related to CH2-N, which was observed at 2.97 ppm. Besides, its 13 Furthermore, at about δ 11.70 ppm, the proton signal of N-H as a broad signal appeared. Moreover, the C=O resonance group of the product appeared at about 174.60 ppm, while the CH3 group of compound CH3SO3H was detected at 39.90 ppm, which means that the reaction between N-methyl-2-pyrrolidone and methane sulphonic acid had taken place.…”

“…Fourier transforms infrared spectroscopy (FTIR) was carried out using a Perkin Elmer Spectrum GX spectrophotometer in the range of 400-4000 cm -1 . Nuclear magnetic resonance spectroscopy (NMR) for 1 H and 13 C was carried with model Joel FCP 400 MHz with CDCl3 and D2O solvent. The electrospray ionization mass spectra (ESI-MS) were recorded on a Bruker MicroTOF-Q (German) mass spectrometer equipped with a Kd Scientific Apparatus syringe pump (USA).…”

“…1 shows the FTIR spectrum of MIM-PS. Furthermore, the 1 H and 13 C-NMR spectra of MIM-PS are presented in Fig. 2 and 3, respectively.…”

“…Deng et al reported the esterification of carboxylic acids with alcohols in acidic chloroaluminate ionic liquid [11]. Some Brønsted acidic ionic liquids, including SO3Hfunctionalized ionic liquid, ionic liquids with acidic counter anion, and protonated N-alkylimidazolium ionic liquids have also been used in esterification reactions [12][13][14]. Although elegant work has been done in this area; there still exist some drawbacks in the above-mentioned catalytic systems.…”