Tert hydroperoxide

Alkylation of benzene with propene to isopropylbenzene (cumene), oxidation of cumene to the corresponding tert-hydroperoxide and cleavage to phenol and acetone (Hock process). 

Chemical derivatization can also be used for structure elucidation in complex mixtures. For instance, dimethyl sulfide has been used to differentiate peracids from other peroxy compounds. The rate of conversion of dimethyl sulfide into dimethyl sulfoxide is almost instantaneous with peracids [Eq. (25)], whereas it is slow with sec- and tert-hydroperoxides [Eq. (26)]. 

In the flask were placed 10.0 g of the propargylic amine (see Chapter lIII-5, Exp. 1). The air in the flask was replaced with nitrogen and a solution of 0.01 mol of KO-tert.-Ci,H,3 in 10 g of THF (free from hydroperoxide) was added. The mixture was warmed at about 40 C. A weakly exothermic reaction was observed and the temperature rose to about 45°C. After 1-2 min the gel originally present, had disappeared almost completely and a brown solution had formed. The refractive index of the solution (note 1) was measured after intervals of about 2 min. After the... 

The first practical method for asymmetric epoxidation of primary and secondary allylic alcohols was developed by K.B. Sharpless in 1980 (T. Katsuki, 1980 K.B. Sharpless, 1983 A, B, 1986 see also D. Hoppe, 1982). Tartaric esters, e.g., DET and DIPT" ( = diethyl and diisopropyl ( + )- or (— )-tartrates), are applied as chiral auxiliaries, titanium tetrakis(2-pro-panolate) as a catalyst and tert-butyl hydroperoxide (= TBHP, Bu OOH) as the oxidant. If the reaction mixture is kept absolutely dry, catalytic amounts of the dialkyl tartrate-titanium(IV) complex are suflicient, which largely facilitates work-up procedures (Y. Gao, 1987). Depending on the tartrate enantiomer used, either one of the 2,3-epoxy alcohols may be obtained with high enantioselectivity. The titanium probably binds to the diol grouping of one tartrate molecule and to the hydroxy groups of the bulky hydroperoxide and of the allylic alcohol... 

Osmate esters are fairly stable but are readily cleaved m the presence of an 0x1 dizing agent such as tert butyl hydroperoxide... 

Because osmium tetraoxide is regenerated m this step alkenes can be converted to vie mal diols using only catalytic amounts of osmium tetraoxide which is both toxic and expensive The entire process is performed m a single operation by simply allowing a solution of the alkene and tert butyl hydroperoxide m tert butyl alcohol containing a small amount of osmium tetraoxide and base to stand for several hours... 

PEROXIDES AND PEROXIDE COMPOUNDS - ORGANIC PEROXIDES] (Vol 18) tert-Alkyl hydroperoxides... 

CINNAMICACID,CINNAMALDEHYDEANDCINNAMYLALCOHOL] (Void) tert-Butyl hydroperoxide... 

Organic hydroperoxides can be prepared by Hquid-phase oxidation of selected hydrocarbons in relatively high yield. Several cycHc processes for hydrogen peroxide manufacture from hydroperoxides have been patented (84,85), and others (86—88) describe the reaction of tert-huty hydroperoxide with sulfuric acid to obtain hydrogen peroxide and coproduct tert-huty alcohol or tert-huty peroxide. 

Derivative Formation. Hydrogen peroxide is an important reagent in the manufacture of organic peroxides, including tert-huty hydroperoxide, benzoyl peroxide, peroxyacetic acid, esters such as tert-huty peroxyacetate, and ketone derivatives such as methyl ethyl ketone peroxide. These are used as polymerization catalysts, cross-linking agents, and oxidants (see Peroxides and peroxide compounds). 

The addition of an oxygen atom to an olefin to generate an epoxide is often catalyzed by soluble molybdenum complexes. The use of alkyl hydroperoxides such as tert-huty hydroperoxide leads to the efficient production of propylene oxide (qv) from propylene in the so-called Oxirane (Halcon or ARCO) process (79). 

Alkyl hydroperoxides form stable alkaU metal salts with caustic however, when equimolar amounts of the hydroperoxide and its sodium salt are present in aqueous solution, rapid decomposition to tert-AcohoX and oxygen occurs (28). 

Commercially, autoxidation is used in the production of a-cumyl hydroperoxide, tert-huty hydroperoxide, -diisopropylbenzene monohydroperoxide, -diisopropylbenzene dihydroperoxide, -menthane hydroperoxide, pinane hydroperoxide, and ethylbenzene hydroperoxide. 

Saponification of alkyl peroxyesters yields alkyl hydroperoxides and carboxylic acids or their alkali metal salts. a-Ether-substituted peroxides can be hydrolyzed to the unsubstituted alkyl hydroperoxides, eg, tert-huty hydroperoxide from tert-huty 2-oxacyclohexyl peroxide [28627-46-5] (62) ... 

The following commercially available dialkyl peroxides are produced according to equations 24—27 di-Z fZ-butyl peroxide from hydrogen peroxide and sulfated tert-huty alcohol or isobutylene dicumyl peroxide from a-cumyl hydroperoxide and cumyl alcohol, cumyl chloride, and/or a-methylstyrene m- and -di(2-/ f2 -butylperoxyisopropyl)ben2ene [2781-00-2] from tert-huty hydroperoxide [75-91-2] and m- and -di(2-hydroxyisopropyl)ben2ene ... 

Olefins react with tert-huty hydroperoxide in the presence of tert-huty hypochlorite, forming tert-huty P-chloroalkyl peroxides (66) ... 

Autoxidation of alkanes generally promotes the formation of alkyl hydroperoxides, but d4-tert-huty peroxide has been obtained in >30% yield by the bromine-catalyzed oxidation of isobutane (66). In the presence of iodine, styrene also has been oxidized to the corresponding peroxide (44). 

In the presence of strong acid catalysts such as sulfuric acid, aUphatic (R CHO) aldehydes react with alkyl hydroperoxides, eg, tert-55ky hydroperoxides, to form hydroxyalkyl alkyl peroxides (1), where X = OH R, = hydrogen, alkyl and = tert — alkyl. 

Alkoxyall l All l Peroxides. / /f-Butyl tetrahydropyran-2-yl peroxide [28627 6-5] (1), where R = tert — butyl, X = OR", R = H, R and R" = 1, 4 butanediyl, has been isolated. This is one of many examples of alkoxyalkyl alkyl peroxides which may be prepared by reaction of hydroperoxides with vinyl ethers (139) ... 

In the presence of strong acid catalysts many commonly used commercial alkyl hydroperoxides decompose to acetone to some extent. Consequendy, the diperoxyketals derived from other ketones and alkyl hydroperoxides are often contaminated with small amounts of diperoxyketals derived from acetone (1, X = OOR, = methyl, R = R = tert — alkyl). 

Some fabrication processes, such as continuous panel processes, are mn at elevated temperatures to improve productivity. Dual-catalyst systems are commonly used to initiate a controlled rapid gel and then a fast cure to complete the cross-linking reaction. Cumene hydroperoxide initiated at 50°C with benzyl trimethyl ammonium hydroxide and copper naphthenate in combination with tert-huty octoate are preferred for panel products. Other heat-initiated catalysts, such as lauroyl peroxide and tert-huty perbenzoate, are optional systems. Eor higher temperature mol ding processes such as pultmsion or matched metal die mol ding at temperatures of 150°C, dual-catalyst systems are usually employed based on /-butyl perbenzoate and 2,5-dimethyl-2,5-di-2-ethyIhexanoylperoxy-hexane (Table 6). 

The hydroperoxide process involves oxidation of propjiene (qv) to propylene oxide by an organic hydroperoxide. An alcohol is produced as a coproduct. Two different hydroperoxides are used commercially that result in / fZ-butanol or 1-phenylethanol as the coproduct. The / fZ-butanol (TBA) has been used as a gasoline additive, dehydrated to isobutjiene, and used as feedstock to produce methyl tert-huty ether (MTBE), a gasoline additive. The 1-phenyl ethanol is dehydrated to styrene. ARCO Chemical has plants producing the TBA coproduct in the United States, Erance, and the Netherlands. Texaco has a TBA coproduct plant in the United States. Styrene coproduct plants are operated by ARCO Chemical in the United States and Japan, Shell in the Netherlands, Repsol in Spain, and Yukong in South Korea. 

Hydroperoxide Process. The hydroperoxide process to propylene oxide involves the basic steps of oxidation of an organic to its hydroperoxide, epoxidation of propylene with the hydroperoxide, purification of the propylene oxide, and conversion of the coproduct alcohol to a useful product for sale. Incorporated into the process are various purification, concentration, and recycle methods to maximize product yields and minimize operating expenses. Commercially, two processes are used. The coproducts are / fZ-butanol, which is converted to methyl tert-huty ether [1634-04-4] (MTBE), and 1-phenyl ethanol, converted to styrene [100-42-5]. The coproducts are produced in a weight ratio of 3—4 1 / fZ-butanol/propylene oxide and 2.4 1 styrene/propylene oxide, respectively. These processes use isobutane (see Hydrocarbons) and ethylbenzene (qv), respectively, to produce the hydroperoxide. Other processes have been proposed based on cyclohexane where aniline is the final coproduct, or on cumene (qv) where a-methyl styrene is the final coproduct. 

The tert-huty hydroperoxide is then mixed with a catalyst solution to react with propylene. Some TBHP decomposes to TBA during this process step. The catalyst is typically an organometaHic that is soluble in the reaction mixture. The metal can be tungsten, vanadium, or molybdenum. Molybdenum complexes with naphthenates or carboxylates provide the best combination of selectivity and reactivity. Catalyst concentrations of 200—500 ppm in a solution of 55% TBHP and 45% TBA are typically used when water content is less than 0.5 wt %. The homogeneous metal catalyst must be removed from solution for disposal or recycle (137,157). Although heterogeneous catalysts can be employed, elution of some of the metal, particularly molybdenum, from the support surface occurs (158). References 159 and 160 discuss possible mechanisms for the catalytic epoxidation of olefins by hydroperoxides. 

Liquid-Phase Epoxidation with Hydroperoxides. Molybdenum, vanadium, and tungsten have been proposed as Hquid-phase catalysts for the oxidation of the ethylene by hydroperoxides to ethylene oxide (205). tert- uty hydroperoxide is the preferred oxidant. The process is similar to the arsenic-catalyzed route, and iacludes the use of organometaUic complexes. 

Di-tert-butyl peroxide (tert-butyl peroxide) [110-05-4] M 146.2, d 0.794, n 1.389. Washed with aqueous AgN03 to remove olefinic impurities, water and dried (MgS04). Freed from /cr/-butyl hydroperoxide by passage through an alumina column [Jackson et al. J Am Chem Soc 107 208 1985], and if necessary two high vacuum distns from room temp to a liquid-air trap [Offenbach and Tobolsky J Am Chem Soc 79 278 1957]. The necessary protection from EXPLOSION should be used. 

Cumene hydroperoxide [95], benzoyl peroxide, or tert-h iiy peroxide [96]. can be used as accelerators with alkylboron initiators. The chain transfer constant for MMA to tributylborane has been estimated to be 0.647, which is comparable to tripropylamine [97]. 

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. 

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