Tert-butyl hydroperoxide preparation

The Sharpless-Katsuki asymmetric epoxidation reaction (most commonly referred by the discovering scientists as the AE reaction) is an efficient and highly selective method for the preparation of a wide variety of chiral epoxy alcohols. The AE reaction is comprised of four key components the substrate allylic alcohol, the titanium isopropoxide precatalyst, the chiral ligand diethyl tartrate, and the terminal oxidant tert-butyl hydroperoxide. The reaction protocol is straightforward and does not require any special handling techniques. The only requirement is that the reacting olefin contains an allylic alcohol. 

The parent indolo[2,3-fl]carbazole (1) has also been the subject of a study probing its reactivity toward oxidizing agents. One of the substrates involved, namely 85 (prepared from 1 and 2,5-dimethoxytetrahydrofuran in the presence of acid), was subjected to treatment with m-chloroperbenzoic acid, to give the dione 86 as the major product and a sensitive compound assigned the hydroxy structure 87. A cleaner reaction took place when 85 underwent oxidation with tert-butyl hydroperoxide assisted by VO(acac)2, to produce 86 exclusively in 86% yield. Likewise, A,N -dimethylindolo[2,3-fl]carbazole furnished the dione 88 on treatment with this combination of reagents (96J(X 413). 

The calcined iron-grafted materials exhibit high selectivity as catalysts for oxidations of alkanes, alkenes and arenes with H2O2 as the oxidants [13a]. A similar method has been used by Tilley et al. to prepare a pseudotetrahedral (Co(II) [Co(4,4 -di Bu-bipy) OSi(0 Bu)3 2]) complex grafted onto the SBA-15 surface and subsequently use it in catalytic oxidation of alkylaromatic substrates with tert-butyl hydroperoxide [14]. Unfortunately, neither iron nor cobalt surface organometaUic compounds have been tested in the recycled catalytic system. 

Materials. Chemically pure solvents and reagent grade ceric ammonium nitrate were used as received. Cumene hydroperoxide was purified via the sodium salt. Lucidol tert-butyl hydroperoxide was purified by low temperature crystallization. Tetralin hydroperoxide, cyclohexenyl hydroperoxide, and 2-phenylbutyl-2-hydroperoxide were prepared by hydrocarbon oxidation and purified by the usual means. 1,1-Diphenyl-ethyl hydroperoxide and triphenylmethyl hydroperoxide were prepared from the alcohols by the acid-catalyzed reaction with hydrogen peroxide (10). 

Materials. Poly (olefin sulfone)s were prepared by copolymerization of liquid mixtures of sulfur dioxide and the appropriate olefin using tert.-butyl hydroperoxide as initiator in the temperature range from —80 to 0°C. The poly (amino acid)s were obtained from Sigma Chemical Co. and used without further purification. The poly (olefin) s were provided by Mr. O. Delatycki and Dr. T. N. Bowmer and were prepared under controlled conditions. The aromatic polysulfones were prepared and purified by Mr. J. Hedrick. The purity of all polymers was checked by H and 13C NMR. 

A polymer-supported Sharpless epoxidation catalyst was prepared using linear poly(tartrate ester) catalyst ligands 43.65 This catalyst system was used in the reaction of tranA-hex-2-en- l-ol with titanium tc/ra-isopropoxide and tert-butyl hydroperoxide to afford the desired epoxide in high chemical yield and moderate enantiomeric excess. 

Very recently, the chemoenzymatic preparation of nootkatone from valencene was described [150]. Nootkatone was prepared from valencene by copper(I) iodide catalysed oxidation with tert-butyl hydroperoxide and hydroxylated at C-9 by Mucor plumbeus and Cephalosporium aphidicola. 

Composition and preparation conditions of mesoporous materials containing titanium are screened to optimise the catalytic activity and selectivity in the epoxidation of cyclohexene using tert-butyl hydroperoxide as oxidant. Important parame-... 

Tetralin hydroperoxide and tert-butyl hydroperoxide were selected for this work, both of which could be prepared readily in a pure state. 

Oxidative cleavage of open-chain ketones or alcohols is seldom a useful preparative procedure, not because these compounds do not undergo oxidation (they do, except for diaryl ketones), but because the result is generally a hopeless mixture. Aryl methyl ketones, such as acetophenone, however, are readily oxidized to aryl carboxylic acids with Re207 and 70% aqueous tert-butyl hydroperoxide. Oxygen with a mixture of manganese and cobalt catalysts give similar oxidative... 

Another approach to designing shape-selective heterogeneous oxidation catalysts was to use redox metal oxides as the pillaring agents in the preparation of pillared clays. These redox pillared clays have been used for a number of selective oxidations. Chromium pillared montmorillonite (Cr-PILC) is an effective catalyst for the selective oxidation of alcohols with tert-butyl hydroperoxide. 7 Primary aliphatic and aromatic alcohols are oxidized to the aldehydes in very good yields. Secondary alcohols are selectively oxidized in the presence of a primary hydroxy group of a diol to give keto alcohols in excellent yields (Eqn. 21.12). 2... 

The reaction of tetraethyl pyrophosphite with perfluoroalkyl iodides in the presence of di-tert-butyl peroxide in l,l,2-trichloro-l,2,2-trifluoroethane (1-113) was described for the first time in 1981 Thermal decomposition of di-tert-butyl peroxide leads to the abstraction of an iodine atom and gives the reactive perfluoroalkyl radical, which reacts with tetraethyl pyrophosphite to produce the perfluoroalkyl phosphonite. Subsequent oxidation with tert-butyl hydroperoxide provides the desiied perfluoroalkylphosphonates in 40-71% yields (Scheme 3.40). 2 a photochemical variant, which avoids heating the reaction mixture with a peroxide, was reported later. This milder method allows the preparation of functionalized perfluoroalkylphosphonates in good yields... 

Figure 4 Effect of preparation method on the reactivity of titania/silica catalysts in the epoxidation of cyclooctene with tert-butyl hydroperoxide in tert-butanol...

Most functional monomers and cross-linkers contain one or more vinyl functionalities. Polymerization of this type of compound for the preparation of MIPs is traditionally performed as a free-radical polymerization, initiated via either ther-molytic or photolytic homolysis of an initiator. One of the most commonly used free radical initiators for this purpose is 2,2 -azobis (isobutyronitrile) (AIBN). Other examples of free-radical polymerization initiators are phenyl-azo-triphenyl-methane, tert-butyl peroxide (TBP), acetyl peroxide, benzoyl peroxide (BPO), lauroyl peroxide, tert-butyl hydroperoxide and tert-butyl perbenzoate. 

The dithiolane was prepared by Schrobel and Grafje (1958) by oxidative cyclization of 3-methyl-l,3-butanedithiol in the presence of tert-butyl hydroperoxide, the thiol itself being obtained by reaction of the corresponding dibromo compound with thiourea. 

Allylic alcohols, for example geraniol, 2-methylallyl alcohol, 3,3-dimethylallyl alcohol, 3-buten-2-ol, l-octen-3-ol, and l-hexen-3-ol, are epoxidized with tert-butyl hydroperoxide in the presence of a vanadyl salen oxo-transfer catalyst in supercritical CO2. The metal catalyst was prepared in a simple two-step, Schiff base-type reaction to form the salen ligand, followed by complexation to the vanadyl group. The use of non-toxic supercritical CO2 in the presence of the new epoxidation vanadium catalyst led to yields and diastereoselectivities that were comparable to those resulting from the use of environmentally hazardous solvents such as CH2CI2 [59]. 

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