Synthesis and Reactions of N-Methylbenzylammonium Fluorochromate(VI) on Silica Gel, a Selective and Efficient Heterogeneous Oxidant

Abstract

N-Methylbenzylammonium fluorochromate(VI) (MBAFC) is easily synthesized by addition of N-methylbenzylamine to an aqueous solution of CrO 3 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.

Some aspects of tetramethylammonium fluorochromate (VI) oxidations and identification of the reduced chromium species

“…Industrial demands have led many workers to search for more ideal oxidants with a number of specifications including: lower cost, higher yields, better selectivity, milder neutral conditions, easier preparations, higher solubility and shorter reaction times [1][2][3]. In recent years, significant improvements were achieved by the use of new oxidizing agents such as: pyridinium dichromate (PDC) [4], pyridinium fluorochromate (PFC) [5], tripropylammonium fluorochromate (TriPAFC) [6], chromium trioxide-3,5-dimethylpyrazole complex (CrO 3 3,5-DMP), [7], tributylammonium chlorochromate (Tri-BACC) [8], 3,5-dimethylpyrazolium fluorochromate (DmpzHFC), [9], quinolinium fluorochromate (QFC) [10], 2,2¢-bipyridinium chlorochromate (BiPCC) [11]. Recently, we synthesized another oxidizing agent, viz., tetramethylammonium fluorochromate (VI) (TMAFC) [12], which is suitable for alcohol oxidation.…”

Oxidation of Aryl Alcohols by Morpholinium Fluorochromate(VI) on Silica Gel, a Selective and Efficient Heterogeneous Reagent

“…Many oxidizing agents have been developed in recent years such as the Collins reagent 1 , chromium trioxide-3,5-dimethylpyrazole complex 2 , pyridinium fluorochromate (PFC) 3,4 , pyridinium chlorochromate (PCC) 5 , pyridinium dichromate (PDC) 6 , 2,2'-bipyridinium chlorochromate (BiPCC) 7 , quinolinium fluorochromate (QFC) 8 , quinolinium chlorochromate 9 , isoquinolium fluorochromate (IQFC) 10 , 3,5-dimethylpyrazolium fluorochromate 11 , 2,6-dicarboxypyridinium chlorochromate 12,13 , N-methylpiperidinium chlorochromate 14 , tetramethylammonium fluorochromate(VI) (TMAFC) 15 , tetrabutylammonium fluorochromate(VI) (TBAFC) 16 , morpholinium chlorochromate (MCC) 17 and benzyltrimethyl ammonium fluorochromate(VI) 18 , etc. We have recently reported new reagents such as N-methylbenzylammonium fluorochromate(VI) (MBAFC) 19 and morpholinium fluorochromate(VI) (MFC) 20 . These reagents are mostly used for the oxidation of alcohols to corresponding aldehydes and ketones.…”

Synthesis, characterization, X-ray structural analysis and study of oxidative properties of propyltriphenylphosphonium bromochromate

“…There is continued interest in the development of new chromium(VI) reagents for the effective and selective oxidation of organic substrates, in particular alcohols, under mild conditions. In recent years, significant improvements were achieved by the use of new oxidizing agents by Marier et al [1], Bhandari et al [2], Meenahshisundaram and Soctaungam [3], such as pyridinium dichromate (PDC), Kassaee et al [4], pyridinium fluorochromate (PFC), Bhattacharjee et al [5], triphenylmethylphosphonium chlorochromate, Hajipour et al [6], chromium trioxide-3,5-dimethylpyrazole complex (CrO 3 3,5-DMP), Corey and Fleet [7], tributylammonium chlorochromate (TriBACC), Ghammamy and. Seyed Sadjadi [8], 3,5-dimethylpyrazolium fluorochromate (DmpzHFC), Srinivasan et al [9], quinolinium fluorochromate (QFC), Bora and Chaudhuri [10], 2,2¢-bipyridinium chlorochromate (BiPCC), Guziec and Luzzio [11].…”