Osmium-Catalyzed Dihydroxylation of Olefins in Acidic Media: Old Process, New Tricks

Dupau, Philippe; Epple, Robert; Thomas, Allen A.; Fokin, Valery V.; Sharpless, K. Barry

doi:10.1002/1615-4169(200206)344:3/4<421::aid-adsc421>3.0.co;2-f

Cited by 232 publications

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“…Recent work by Sharpless, Fokin, and coworkers has uncovered that electron-deficient olefins can be converted into the corresponding diols much more efficiently when the reaction medium is kept acidic. [181] One of the most useful additives in this context is citric acid (2.0 equiv), which Scheme 31. Rearrangement of a squaric acid derivative to a vinylketene, which further reacts to form the tricyclic product 34. in combination with 4-methylmorpholine N-oxide (NMO) as the reoxidant for Os VI and K 2 OsO 2 (OH) 4 (0.2 mol %) as a stable, nonvolatile substitute for OsO 4 , allows the conversion of many olefinic substrates into their corresponding diols at ambient temperatures.…”

Section: Oxidationsmentioning

confidence: 99%

“…In specific cases, such as for the extremely electron-deficient olefin 42 (Scheme 34), the reaction had to be carried out under microwave irradiation at 120 8C to produce the pure diol 43 in 81 % yield. [181] Another industrially important oxidation reaction is the conversion of cyclohexene into adipic acid. The well-known Noyori method uses hydrogen peroxide, a catalytic amount of tungstate, and a phase-transfer catalyst to afford the clean oxidation of cyclohexene to adipic acid.…”

Section: Oxidationsmentioning

confidence: 99%

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Controlled Microwave Heating in Modern Organic Synthesis

2004

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Although fire is now rarely used in synthetic chemistry, it was not until Robert Bunsen invented the burner in 1855 that the energy from this heat source could be applied to a reaction vessel in a focused manner. The Bunsen burner was later superseded by the isomantle, oil bath, or hot plate as a source for applying heat to a chemical reaction. In the past few years, heating and driving chemical reactions by microwave energy has been an increasingly popular theme in the scientific community. This nonclassical heating technique is slowly moving from a laboratory curiosity to an established technique that is heavily used in both academia and industry. The efficiency of “microwave flash heating” in dramatically reducing reaction times (from days and hours to minutes and seconds) is just one of the many advantages. This Review highlights recent applications of controlled microwave heating in modern organic synthesis, and discusses some of the underlying phenomena and issues involved.

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Section: Oxidationsmentioning

confidence: 99%

Section: Oxidationsmentioning

confidence: 99%

Controlled Microwave Heating in Modern Organic Synthesis

2004

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“…The ozonidation reactions were reported to be fast, but incomplete, and some by-products were also formed [14]. However, the addition of OsO 4 to olefins is a selective and reliable organic transformation for two reasons: (1) OsO 4 reacts with virtually all olefins, and (2) it reacts slowly, if at all, with other common organic functional groups [15]. The use of OsO 4 for vicinal di-hydroxylation of double bonds in order to determine olefinic sites in FAs by gas-chromatography (GC)-MS was described in 1965 [16].…”

mentioning

confidence: 99%

Total structure characterization of unsaturated acidic phospholipids provided by vicinal di-hydroxylation of fatty acid double bonds and negative electrospray ionization mass spectrometry

Moe

Anderssen

Strøm

et al. 2005

J. Am. Soc. Mass Spectrom.

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In the present work, the unsaturated fatty acid substituents of some phosphatidic acid, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol species were converted to their 1,2-di-hydroxy derivatives by OsO 4 . The subsequent electrospray ionization tandem low-energy mass spectrometry analysis of the deprotonated species allowed positional determination of the double bonds by the production of specific product-ions. The productions are formed by charge-remote and charge-proximate homolytic cleavages as well as charge-directed heterolytic cleavages and rearrangements. The commercial availability of pure species of the phospholipids in question was limited, and a number of species were therefore synthesized. The developed method was used to fully characterize the two isobaric phosphatidylglycerol species 16:0/16:1⌬ 9 and 16:0/16:1⌬ 10 extracted from the bacteria Methylococcus capsulatus. The presence of these fatty acids was supported by a gas-chromatography mass spectrometry investigation of the dimethyloxazoline derivatives of the species of the lipid extract. The present work demonstrates that a total structure characterization of acidic unsaturated phospholipids in isolate or in mixtures is accomplished by vicinal di-hydroxylation of olefinic sites and subsequent electrospray ionization mass spectrometry of the derivatized phospholipids. (J Am Soc Mass Spectrom 2005, 16, 46 -59)

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“…It is well known that electron-deficient double bonds are slug- gish towards osmylation. The catalytic cycle shuts down and the reaction stops totally because of the rising pH, 10 due to the formation of basic N-methylmorpholine. This can be avoided through the use of acid to trap the amine, thus keeping the catalytic cycle in motion.…”

mentioning

confidence: 99%

“…Acidifying the reaction media with 75 mol% citric acid, however, had a tremendous effect. 10 Under these conditions the reaction was complete in 5.5 hours and provided the diol 14 in practically quantitative yield. In both cases -the traditional Upjohn procedure and the use of citric acid as additive -the oxidation reaction produced the alcohol 14 as a single diastereoisomer.…”

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confidence: 99%