Synthesis and reactions of N-methylbenzylammonium fluorochromate(VI) on silica gel, a selective and efficient heterogeneous oxidant.
N-Methylbenzylammonium fluorochromate(VI) (MBAFC) is easily synthesized by addition of N-methylbenzylamine to an aqueous solution of CrO3 and HF. MBAFC shows selectivity in the oxidation of aryl alcohols to their corresponding aldehydes and ketones under mild conditions. The durability, ease of work up and efficiency of MBAFC are considerably increased upon its absorption on silica gel.
Isoquinolinium Fluorochromate: A New and Efficient Oxidant for Organic Substrates
Abstract Isoquinolinium fluorochromate is a versatile reagent for the effective and selective oxidation of organic substrates, in particular for alcohols, under mild conditions.
Quantum/Classical Mechanical Comparison of Cation−π Interactions between Tetramethylammonium and Benzene
To consider whether existing molecular force fields can adequately reproduce cation−π interactions without adding special interaction terms, theoretical calculations with geometry optimization were performed on three configurations of tetramethylammonium (TMA) interacting via one, two, or three N-methyl groups with a benzene ring, by use of density-functional theory (DFT) methods B3LYP/6-31G* and B3LYP/6-311G**, ab initio method MP2/6-31G*, and molecular mechanic methods EFF, Tinker's Amber and MM3. Only the first configuration was found to be stable from the DFT and MP2 results, and its geometry was found to be highly flexible. ESP CHELPG charges estimated from the DFT and MP2 calculations were used to modify the atomic charges of the force fields employed in the molecular mechanics calculations to improve agreement with the BSSE-corrected binding energies deduced from the DFT and MP2 results. After this modification, the molecular mechanics results were found to be in good agreement with those obtained ...