T-butyl hydrogen peroxide

Recently an oxidative amidation protocol, employing copper (I) as a catalyst, was developed by C.-J. Li [14]. The proposed mechanism, shown in Scheme 14.1, involves nucleophilic addition of the amine free base 8 to aldehyde 7 to afford hemiaminal intermediate 9, which is then oxidized by copper(I)/t-butyl hydrogen-peroxide (Cu(l)/TBHP) to generate the desired amide products 10 [15, 16]. 

One of the best known oxidative transformations of alkenes is the conversion of terminal alkenes to methyl ketones, known as the Wacker oxidation. While this reaction is used industrially on extremely large scale, its application in laboratory settings (known as the Tsuji-Wacker oxidation) has been problematic. This is due to selectivity problems with several substrate classes as well as the need for co-oxidants, typically copper salts. The use of copper has prevented the use of ligands on Pd to modulate catalysis, which could potentially help overcome some of the issues associated with this reaction. One of the first ligand-modulated Tsuji-Wacker reactions was developed by Cornell and Sigman using a [(NHC)Pd] catalyst with t-butyl hydrogen peroxide (TBHP) as the sole oxidant (Scheme 12.16). ... 

Acrylic/styrene/acrylonitrile terpolymer Allyl isocyanate Azelaic acid t-Butyl cumyl peroxide 4-t-Butyl-o-thiocresol Dimer acid, hydrogenated Dipentene-styrene resin t-Hexadecanethiol 1-Hexene n-Hexyl acrylate... 

The reagent Is expensive and poisonous, consequently the hydroxylation procedure is employed only for the conversion of rare or expensive alkenes (e.g., in the steroid field) into the glycols. Another method for hydroxylation utilises catalytic amounts of osmium tetroxide rather than the stoichiometric quantity the reagent is hydrogen peroxide in tert.-butyl alcohol This reagent converts, for example, cyc/ohexene into cis 1 2- t/ohexanedlol. 

When heated in the presence of a carboxyHc acid, cinnamyl alcohol is converted to the corresponding ester. Oxidation to cinnamaldehyde is readily accompHshed under Oppenauer conditions with furfural as a hydrogen acceptor in the presence of aluminum isopropoxide (44). Cinnamic acid is produced directly with strong oxidants such as chromic acid and nickel peroxide. The use of t-butyl hydroperoxide with vanadium pentoxide catalysis offers a selective method for epoxidation of the olefinic double bond of cinnamyl alcohol (45). 

A teehnique that is a convenient source of radieals for study by EPR involves photolysis of a mixture of di-t-butyl peroxide, triethylsilane, and the alkyl bromide corresponding to the radieal to be studied. Photolysis of the peroxide gives t-butoxy radieals, whieh selectively abstract hydrogen from the silane. This reactive silicon radieal in turn abstracts bromine, generating the alkyl radieal at a steady-state eoncentration suitable for EPR study. 

In a special case involving a C-ring aza steroid, it was found that epoxida-tion of a A -20-keto grouping using a two-phase system (t-butyl alcohol-aqueous potassium hydroxide-30 % hydrogen peroxide) was much superior to the standard hydrogen peroxide-aqueous methanolic alkali conditions. 

Laboratory studies have generally focused on the diisopropyl, dicyclohexyl and di-t-butyl derivatives. These and the. s-butyl and 2-cthylhcxyl derivatives arc commercially available.189 The rates of decomposition of the peroxydicarbonates show significant dependence on the reaction medium and their concentration. This dependence is, however, less marked than for the diacyl peroxides (36) (see 3.3.1.1.4). Induced decomposition may involve a mechanism analogous to that described for diacyl peroxides. However, a more important mechanism for primary and secondary peroxydicarbonates involves abstraction of an cx-hydrogen (Scheme 3.31).190... 

Oxidative cleavage of oxosulfonium ylides as well as of sulfoximines leads to sulfone formation. In the course of oxidations of dialkoxy sulfuranes(IV) by hydrogen peroxide" or t-butyl hydroperoxide , sulfone formation takes place (equation 99). 

Ethylene-propylene and silicone rubbers are crosslinked by compounding with a peroxide such as dicumyl peroxide or di-t-butyl peroxide and then heating the mixture. Peroxide cross-linking involves the formation of polymer radicals via hydrogen abstraction by the peroxy radicals formed from the decomposition of the peroxide. Crosslinks are formed by coupling of the polymer radicals... 

Oxidation of thiophene and its derivatives was studied using hydrogen peroxide (H2O2), t-butyl-hydroperoxide and Ti-Beta redox molecular sieve as selective oxidation catalysts. A new reaction pathway was discovered and investigated using C-13 NMR, GC, GC-MS, HPLC, ion chromatography, and XANES. The thiophene oxidized to thiophene-sesquioxide [3a,4,7,7a-tetrahydro-4,7-epithiobenzo[b]-thiophene 1,1.8-trioxide] and the sesquioxide oxidized mostly to sulfate. 2-Methyl-thiophene and 2,5 dimethylthiophene also oxidized to sulfate and sulfone products. The Benzothiophene oxidation product was sulfone. This proposed new reaction pathway is different from prior literature, which reported the formation of thiophene 1,1-dioxide (sulfone ) as a stable oxidation product... 

The A-t-butylation of aromatic amines has been described. The benzotriazoles 128 (R1 = Pr, i-Pr or t-Bu R2 = Ph, Ar or 2- or 3-pyridyl) react with hydrogen peroxide under... 

The oxidation procedure is amenable to a number of modifications. The solvent used may be varied carbon tetrachloride, hexane, toluene and dichloro-methane have all been used successfully, although the latter two are the solvents of choice. The most common oxidant is aqueous hydrogen peroxide, but other oxidants such as t-butyl hydroperoxide [4], sodium perborate (Table 1, Entries 18 and 22) and sodium percarbonate [4] have also been employed. It is interesting to note the effect of a change of oxidant. Using alkaline hydrogen peroxide... 

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