Ravindra R. Pal

Influence of ionic liquids on the phase transfer-catalysed enantioselective Michael reaction

Abstract The enantioselective Michael addition of dimethyl malonate to 1,3-diphenylprop-2-en-1-one promoted by a quaternary derived ammonium salt from quinine as a phase transfer catalyst in different ionic liquids, 1-butyl-3-methyl imidazolium hexafluorophosphate, [bmim]PF 6 , 1-butyl-3-methyl pyridinium tetrafluoroborate, [bpy]BF 4 , 1-butyl-3-methyl imidazolium tetrafluoroborate [bmim]BF 4 as well as in conventional organic solvents was studied.

Optically Active Metallo-Supramolecular Polymers Derived from Chiral Bis-terpyridines

The optically active metallo-supramolecular polymers were successfully synthesized via complexation of Fe(II) ions with new bis-terpyridines containing chiral tetra-ethylene glycol units at the ortho-position of the peripheral pyridine rings. In addition, we also revealed solvent and temperature effects toward assembly and dis-assembly behavior of polymers.

Preparation and Characterization of Chiral Oxazaborolidine Complex Immobilized SBA-15 and Its Application in the Asymmetric Reduction of Prochiral Ketones

The immobilization of chiral oxazaborolidine complex in the well-ordered mesochannels of SBA-15 is demonstrated by a postsynthetic approach using 3-aminopropyltriethoxysilane as a reactive surface modifier. The immobilized catalysts are characterized by various techniques, such as XRD, nitrogen adsorption, HRSEM, UV/Vis diffuse reflectance spectroscopy, and FTIR spectroscopy. The catalysts are used for the enantioselective reduction of aromatic prochiral ketones. The activity of the chiral oxazaborolidine complex immobilized SBA-15 catalysts is also compared with that of the pure chiral oxazaborolidine complex, which is a homogeneous catalyst. It is found that the activity of the chiral complex immobilized SBA-15 heterogeneous catalyst is comparable with that of the homogeneous catalyst.