Polymer-supported perruthenate

Hinzen B, Ley SV (1998) Synthesis of isoxazolidines using polymer supported perruthenate (PSP). J Chem Soc Perkin Trans 11-2... 

A molecular sieves (0.5 g) and polymer-supported perruthenate (0.1 g), prepared by adding KRu04 (10 mg, 1 mmol) to Amberlyst IR-27 resin (1 g), in CH2C12 or MeCN (5 ml) at room temperature until TLC analysis indicates complete consumption of the alcohol (ca. 16 h). The mixture is filtered and the filtrate evaporated to yield the carbonyl compound [e.g. PhCHO, >95% (16 h) PhCH=CHCHO, >95% CH2=CH(CH2)2CHO, 62% n-C7HI5CHO, 54% cyclohexanone, 50%]. The resin can be reused without loss of activity. 

Hinzen, B. Ley, S. V. Polymer Supported Perruthenate A New Oxidant for Clean Organic Synthesis, J. Chem. Soc. Perkin. 11997, 1907. 

Hinzen, B., Lenz, R., Ley, S. V. Polymer supported perruthenate (PSP). Clean oxidation of primary alcohols to carbonyl compounds using oxygen as cooxidant. Synthesis 1998, 977-979. 

The difficulties associated with the chromium reagents (stoichiometric amounts required harsh conditions low selectivity) [95-97] led to the development of polymer-supported perruthenate 124 by Ley et al. [98]. These efforts were built upon a large body of experience with soluble salts of the perruthenate ion, e.g., tetra-propylammonium permthenate (TRAP) [99, 100]. The reagent 124 was prepared by prolonged exposure of anion-exchange resin (125) to an aqueous solution of potassium perruthenate 126. 

Ley et al. have described the use of a combination of an oxidant, namely polymer-supported perruthenate 124, together with a reducing agent, namely polymer-supported cyanoborohydride 154. Readily available alcohols as primary feedstock were oxidized to intermediate 153 and further reacted with amines to afford more highly substituted amines, e.g., 155 (Scheme 29) [121]. 

The TPAP oxidation developed by Griffith and Ley [41] has proven to be a very important tool in organic synthesis. The polymer-supported perruthenate (PSP) version, first developed in the Ley group [42], enables the use of the reagent either stoichiometrically or catalytically in tandem with a co-oxidant. The power of PSP... 

Tetrapropylammonium perruthenate Pr4N+Ru04 and N-methylmorpholine-N-oxide (NMO) as catalytic oxidants of primary, secondary, allylic and benzylic alcohols to carbonyl derivatives. The same catalyst polymer supported perruthenate (PSP) used as efficient oxidant (see 1st edition). 

Related and Modified Reagents. In addition to the standard reagent, a polymer-supported perruthenate (PSP) compound has been described. i Recent work has also examined the doping of organically modified silicas (ormosils) with TPAP via a sol-gel process, 7 which enhances the general versatility and reusability of TPAP catalysts. The use of supercritical carbon dioxide as a solvent has also been investigated. TPAP has also found use as a convenient source of ruthenium in mthenium-catalyzed hypochlorite oxidations. ... 

Toluene, 75-85 °C 10mol% polymer- supported perruthenate (PSP) > Toluene, 70-80 °C, 4AmS, 5mol% tetrapropyl- ammoniumperruthenate (TPAP) > Toluene, 75 °C, 10mol% TPAP-doped sol-gel ormosil )... 

TRAP [69] can be used as an effective catalyst for the aerobic oxidation of alcohols to give the corresponding carbonyl compounds (Eq. (7.39)) [88]. A polymer-supported perruthenate (PSP) and a perruthenate immobilized within MCM-41 can be used for heterogeneous oxidation of alcohols [89]. Water-soluble diruthenium complex [Ru2(OAc)3(C03)[ is effective for aerobic oxidation of alcohols in water [90]. 

Substrate Toluene, 75-85°C 10 mol% polymer supported perruthenate (PSP) Carbonyl yield Toluene, 70-80 C, 4AMS,5mol% tetrapropyl-ammo- niumperruthenate TPAP) Toluene, 75 C, 10mol%TPAP doped sol-gel omtosil ... 

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