Novel ionic liquid 1,3-disulfonic acid imidazolium hydrogen sulfate {[Dsim] HSO4 } efficiently catalyzed N-boc protection of amines

Design, characterization and application of silica-bonded imidazolium-sulfonic acid chloride as a novel, active and efficient nanostructured catalyst in the synthesis of hexahydroquinolines

“…In this work, in continuation of our previous studies on the preparation and applications of acidic ILs and solid salts in organic transformations [30][31][32][33][34][35][36][37][38][39][40][41][42], and also previous works on the synthesis of silica-bonded imidazolium compounds [43][44][45][46], we have synthesized silica-bonded imidazolium-sulfonic acid chloride (SBISAC) (Figure 1) in which SAFIS have been immobilized on silica gel, and characterized it by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). Then, we have utilized SBISAC as a highly efficient, stable, reusable and heterogeneous nanocatalyst for the preparation of hexahydroquinolines at 50 °C under solvent-free conditions (Scheme 1).…”

“…Recently, we introduced a new category of acidic ionic liquids (ILs) and solid salts, namely sulfonic acid-functionalized imidazolium salts (SAFIS) which published in this journal [30], and applied them as organocatalysts or organoreagents for preparation of 1-amidoalkyl-2-naphthols [30], N-sulfonyl imines [31], nitro aromatic compounds [32,33], bis(indolyl)methans [34], benzimidazoles [35], xanthenes [36], 1-carbamatoalkyl-2-naphthols [37], 4,4'-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s [38], t-butyl aryl carbamates [39], 1,2,4,5-tetrasubstituted imidazoles [40], β-acetamido ketones [41], and hexahydroquinolines [42].…”

Synthesis of 2 H- indazolo[2,1- b ]phthalazine-1,6,11(13 H )-triones using 1,4-disulfo-1,4-diazabicyclo[2.2.2]octane-1,4-diium dihydrogen sulfate {DABCO(HSO 3 ) 2 (HSO 4 ) 2 } as a new ionic liquid catalyst

“…FT-IR spectra were recorded on a Perkin-Elmer spectrum BX series. 1 HNMR and 13 CNMR spectra were determined on Bruker AV-400 and Bruker Avance Spectrospin 300 MHz spectrometers using TMS as internal standard. To investigate the morphology of DABCO and [DABCO](HSO 3 ) 2 (HSO 4 ) 2 samples, scanning electron microscopy (SEM) images were obtained on a Philips, XL30.…”

“…Ionic Liquids (ILs) have received considerable interest as eco-friendly solvents, catalysts and reagents in the context of green synthesis, because of their unique properties, such as low volatility, non-flammability, high thermal stability, negligible vapor pressure and ability to dissolve a wide range of materials [1,2]. In recent years and because of these important properties, various reactions have been investigated using ionic liquids as catalyst and/ or reaction media [3].…”

Silica-bonded 1,4-diaza-bicyclo[2.2.2]octane-sulfonic acid chloride catalyzed synthesis of spiropyran derivatives

“…Recently, we have prepared a new category of ionic liquids and solid salts (with an organic cation), namely sulfonic acid functionalized imidazolium salts (SAFIS) [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. In this class of salts, S-N bond formation in imidazole ring, as five member's heterocyclic compounds, was reported for the first time.…”