Secondary oxidants oxone

Apart from sodium hypochlorite, a number of alternative secondary oxidants for TEMPO-mediated alcohol oxidations can be employed. These include cerium (IV) ammonium nitrate (CAN),24 trichloroisocyanuric acid (TCCA),25 oxone ,26 MCPBA,2,3,7 PhI(OAc)2,27 W-chlorosuccinimide,28 sodium bromite,29 electrooxidation,8,21 H5IO626 and a polymer-attached diacetoxybromide (I) complex.30... 

Primary and secondary aliphatic nitro compounds have been oxidized to aldehydes and ketones, respectively (RR CHN02 RR C=0) with sodium chlorite under phase-transfer conditions, TPAP, Oxone , as well as with other reagents. 

All classes of primary amine (including primary, secondary, and tertiary alkyl as well as aryl) are oxidized to nitro compounds in high yields with dimethyl dioxirane." Other reagents that oxidize various types of primary amines to nitro compounds are dry ozone, various peroxyacids," MeRe03/H202,"" Oxone ," ° tcrt-butyl hydroperoxide in the presence of certain molybdenum and vanadium compounds, and sodium perborate." ... 

Dimethyl dioxirane in wet acetone oxidizes isocyanates to nitro compounds (RNCO —> RN02). Oximes can be oxidized to nitro compounds with peroxytri-fluoroacetic acid, or Oxone ," sodiumperborate," among other ways. " Primary and secondary alkyl azides have been converted to nitro compounds by treatment with PhjP followed by ozone. Aromatic nitroso compounds are easily oxidized to nitro compounds by many oxidizing agents. ... 

Nitrones can also be obtained in high yields by treating secondary amines with DMD (Scheme 2.8) (71). Oxidation of pyrrolidine (13) at 0°C with DMD (produced in situ from oxone and acetone Brik procedure ) leads to gem-bisphos-phorylated nitrone (14) (Scheme 2.8) (72). 

Primary and secondary alcohols were selectively oxidized to the corresponding aldehydes and ketones, respectively, by using Oxone in the presence of a catalytic amount of TEMPO (2,2,6,6-tetramethyl-l-oxypiperidinyl). This reaction has been proved to be a highly selective and efficient oxidation reaction, where a catalytic amount of TEMPO plays an important role. Thus TBDMS protected benzyl alcohols were oxidized selectively to benzaldehydes in 81% yield, without affecting the TBDMS moiety. 

Oxone has been successfully used in aprotic solvents for oxidation reactions by dispersing it on an alumina surface. Thus, the oxidation of secondary aliphatic, alicyclic and benzylic alcohols using Oxone/wet alumina oxide in CH2CI2 or CH3CN afforded ketones in good to excellent yields (70-96%). Similarly, the conversion of cycloalkanones to lactones is also reported. 

Aliphatic primary amines are known to be oxidized by dimethyl dioxiranes to various products such as oximes, nitroso dimers, nitroalkanes, nitrones and oxazrridines under various conditions depending upon the oxidation reaction . In contrast, when secondary amines lacking a-hydrogens are allowed to react with Oxone and PTC in buffered acetone solution at 0 °C, nitroxides are obtained in good yields in a few minutes (equation 61) . 

Two tandem alkene metathesis-oxidation procedures using Grubb s second-generation ruthenium catalyst resulted in unique functional group transformations. Use of sodium periodate and cerium(III) chloride, in acetonitrile-water, furnished cis-diols. Oxidation with Oxone, in the presence of sodium hydrogencarbonate, yielded a-hydroxy ketones.296 Secondary alcohols are oxidized to ketones by a hydrogen... 

Whereas the chiral TEMPO analog 87 was used to resolve racemic secondary alcohols, the D-fructose-derived ketone 88 [137] proved useful for oxidative resolution of racemic diols (Table 10.13) [138, 139], Persulfate in the form of Oxone, Curox, etc., served as the final oxidizing agent, and the dioxirane generated from the ketone 88 is the chiral active species. Because of the relatively low conversions (except for unsubstituted dihydrobenzoin) at which the ee stated were achieved, the method currently seems to be of less practical value. Furthermore, typically 3 equiv. ketone 88 had to be employed [138, 139]. 

The standard oxidation procedure employs 30% hydrogen peroxide and 3 M sodium hydroxide. However, functionalities sensitive to strong alkali require milder conditions. In such cases, buffering, simultaneous addition of base and peroxide,492 or oxidation with Oxone ,493 triethylamine A-oxide,494-498 peracids,499,500 or sodium hypochlorite50 were recommended. Oxygen has been rarely used for such purpose,502 but trialkylboranes in bromoperfluorooctane were cleanly reacted with oxygen with the retention of configuration of the secondary alkylboranes (Equation (104)).503... 

Relatively rare reactions are chemical oxidations of secondary alcohols to ketones by derivatives of hydrogen peroxide potassium peroxymono-sulfate (Oxone) [205] and m-chloroperoxybenzoic acid [276]. These compounds do not offer any advantages over more-common oxidants. 

Interestingly, the reaction of a solid slurry of Oxone and wet Alumina with solutions of cyclic ketones in CH2CI2 provokes Baeyer-Villiger oxidation to give the corresponding lactones (eq 2). The same wet alumina-Oxone reagent can be used to oxidize secondary alcohols to ketones (eq 3). Aldehydes are oxidized to acids by aqueous Oxone. ... 

Oxone oxidizes metal complexes including tris[(2-oxazolinyl)-phenolato] manganese(III) which, in conjunction with -Bu4NBr, is an effective oxidant for aromatic and primary and secondary aliphatic alcohols. ... 

Because of Oxone s acidic nature, (V-nitrosation of secondary amines is possible with the use of sodium nitrite in the presence of wet Si02 (eq 55). Nitrophenols can be obtained via nitrosation-oxidation of phenols under similar conditions (eq 56). Although acidic, the use of Oxone for these reactions eliminates the need for strong acids to generate NO+ unlike traditional methods. Nitrosoarenes can also be prepared by oxidation of anilines with Oxone (eq 57). ... 

Oxone adsorbed on silica gel or alumina is a very effective oxidant for the selective oxidation of primary and secondary amines to hydroxylamines without overoxidation. These reactions can even be accomplished under solvent-free conditions and with very short reaction times with heating or microwave irradiation (eq 53). Pyridine and trialkylamines were also readily oxidized to their A-oxides. It is suggested that the hydroxylamines are protected from overoxidation because of their strong adsorption to the silica gel or alumina surface. 

Section 3.2). Catalytic application of the iodine(V) species in the oxidation of alcohols has been reviewed by Uyanik and Ishihara [10, 75]. The first examples of a catalytic application of an iodine(V) species (i.e., IBX) in the oxidation of alcohols using Oxone as a stoichiometric oxidant were independently reported by the groups of Vinod [4] in 2005 and Giannis [5] in 2006. Vinod s group employed 20-40 mol% of 2-iodobenzoic acid in a water-acetonitrile biphasic solvent system, in which primary and secondary alcohols were oxidized to carboxylic acids and ketones, respectively (Scheme 4.44) [4]. 

Based on studies of the RuCls-catalyzed disproportionation of iodine(III) species to iodobenzene and iodylbenzene [53, 94-96], a mild and efficient tandem catalytic system for the oxidation of alcohols and hydrocarbons via a Ru(in)-catalyzed reoxidation of ArlO to ArI02 using Oxone as a stoichiometric oxidant has been developed [53, 96, 97]. In particular, various alcohols are smoothly oxidized in the presence of catalytic Phi and RuCls in aqueous acetonitrile at room temperature to afford the respective ketones from secondary alcohols, or carboxylic acids from primary alcohols, in excellent isolated yields (Scheme 4.59) [97]. 

Several cyclodextrin ketones with a ketone attached to the secondary face of the cyclodextrin in the form of a 2,3-0-( 1,3-acetone) group (79), and some selected cyclodextrin ketones having the ketone at the primary face, were investigated for their catalysis of epoxidation of stilbenes and styrene by oxone in 1 1 acetonitrile/H20. It was found that secondary face ketones were better catalysts giving a cat uncat over 10, and more stereoselective giving up to 76% ee in (5)-styrene oxide. ... 

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