Abstractmagnified imageA series of novel gemini dicationic acidic ionic liquids (GDAILs), compounds 1–3 carrying two SO3H groups at the cation moieties and having anions of the type CF3SO$\rm{ _3^ - }$, were synthesized in good yields (Scheme 1). Some physicochemical properties of 1–3 were determined; due to their unique structures, these novel GDAILs showed noticeable hydrophilic properties and strong acidities (Table 1). Beckmann rearrangements of oximes catalyzed by 1, 2, or 3/zinc chloride (GDAIL/ZnCl2) were investigated (Scheme 2); the corresponding amides were formed in up to 99% yield in the presence of 5 mol‐% of GDAIL/ZnCl2 catalyst under optimized conditions (Tables 2 and 3). The peculiar solubilities of 1–3 made the separation of the catalysts from the products very facile, and the catalytic system could be recycled and reused for three times.
Abstractmagnified imageA series of novel gemini dicationic acidic ionic liquids (GDAILs), compounds 1–3 carrying two SO3H groups at the cation moieties and having anions of the type CF3SO$\rm{ _3^ - }$, were synthesized in good yields (Scheme 1). Some physicochemical properties of 1–3 were determined; due to their unique structures, these novel GDAILs showed noticeable hydrophilic properties and strong acidities (Table 1). Beckmann rearrangements of oximes catalyzed by 1, 2, or 3/zinc chloride (GDAIL/ZnCl2) were investigated (Scheme 2); the corresponding amides were formed in up to 99% yield in the presence of 5 mol‐% of GDAIL/ZnCl2 catalyst under optimized conditions (Tables 2 and 3). The peculiar solubilities of 1–3 made the separation of the catalysts from the products very facile, and the catalytic system could be recycled and reused for three times.
Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands
作者:D. Prajapati、C. Schulzke、M. K. Kindermann、A. R. Kapdi
DOI:10.1039/c5ra10561g
日期:——
A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent system at ambient temperature with catalyst loading of 0.1 mol%. This reaction was also found to proceed smoothly in water although at a slightly elevated temperature of 80 °C. 2,6-Disubstituted and diversely