Ferf-butylhydroperoxide

The titanosilicate version of UTD-1 has been shown to be an effective catalyst for the oxidation of alkanes, alkenes, and alcohols (77-79) by using peroxides as the oxidant. The large pores of Ti-UTD-1 readily accommodate large molecules such as 2,6-di-ferf-butylphenol (2,6-DTBP). The bulky 2,6-DTBP substrate can be converted to the corresponding quinone with activity and selectivity comparable to the mesoporous catalysts Ti-MCM-41 and Ti-HMS (80), where HMS = hexagonal mesoporous silica. Both Ti-UTD-1 and UTD-1 have also been prepared as oriented thin films via a laser ablation technique (81-85). Continuous UTD-1 membranes with the channels oriented normal to the substrate surface have been employed in a catalytic oxidation-separation process (82). At room temperature, a cyclohexene-ferf-butylhydroperoxide was passed through the membrane and epoxidation products were trapped on the down stream side. The UTD-1 membranes supported on metal frits have also been evaluated for the separation of linear paraffins and aromatics (83). In a model separation of n-hexane and toluene, enhanced permeation of the linear alkane was observed. Oriented UTD-1 films have also been evenly coated on small 3D objects such as glass and metal beads (84, 85). 

A second nonselective synthesis involved chain extension of the tosylate of ( )-citronellol (82) with 2-methylpentyl magnesium bromide and lithium tetrachlorocuprate catalysis to give the carbon skeleton 83 (Scheme 12A) [92]. Allylic oxidation with Se02 and ferf-butylhydroperoxide, hydrogenation of the... 

Some unstable peroxy esters are also reported. The reaction of pentaphenylphosphine with ferf-butylhydroperoxide or silicon and germanium hydroperoxides gave the corresponding peroxy derivatives 56, which cannot be isolated (equation 91). 

See ferf-Butylhydroperoxide Toluene, Dinitrogen pentaoxide See other PEROXYESTERS... 

As shown in Scheme 7, lipase-assisted resolution of the racemic hydroxy ester ( )-45 allowed for isolation of chiral non-racemic enantiomer 45, which served to arrive at both diol 46 (via ester reduction) and all-cis epoxide 47 (via ferf-butylhydroperoxide treatment). In a remarkably flexible fashion, cyclopentene 46 was then used as the direct precursor of 3-methyl-branched P-D-ribocarbafuranose 48, P-D-... 

With chiral ligands, the transition-metal catalyst-hydroperoxide complex yields optically active oxiranes. " One of the most significant advances in the formation of chiral epoxides from allyl alcohols has recently been reported by the Sharpless group. Using (-l-)-tartaric acid, ferf-butylhydroperoxide, and titanium isopropoxide, they were able to obtain chiral epoxides in very high enantiomeric excess. The enantiomeric epoxide can be obtained by employing (—)-tartaric acid (Eq. 33a). 

The mechanism of epoxidation of propylene by ferf-butylhydroperoxide on V(V) complexes has been thoroughly investigated by Mimoun [488] and bears many similarities to epoxidation by Mo(VI) complexes. Notable conclusions are the following (a) The reaction is highly stereoselective, cis olefins give cis epoxides and trans olefins give trans epoxides, (b) The reactivity of olefins increases with... 

Secondary alcohols have been oxidized to ketones with excess ferf-butylhydroperoxide in up to 93-99% yields using a zirconium catalyst.250 Zirconium catalysts have also been used with ferf-butylhydroperoxide in the oxidation of aromatic amines to nitro compounds and of phenols to quinones. Allylic oxidation of steroids in 75-84% yields has been performed with ferf-butylhydroperoxide and cop-... 

MAGNESIUM NITRATE or MAGNESIUM(H) NITRATE (10377-60-3) A powerful oxidizer. Reacts violently with dimethylfoimamide, reducing agents, combustible materials, fuels, organic substances, metal powders, potassium hexanitrocobalite(III) (C.I. pigment yellow), sodium acetyUde, and easily oxidizable matter. Incompatible with aluminum, ammonium hexacyanoferrate(II), ferf-butylhydroperoxide, citric acid, ethanol, ferrocyanides, hydrazinium perchlorate, isopropyl chlorocarbonate, metal phosphinates, nitrosyl perchlorate, organic azides, phosphorus, sodium thiosulfate, sulfamic acid, thiocyanates, tin(II) fluoride, and many other substances. 

The vanadium oxide clusters in 5 showed catalytic activity in the sulfoxidation of thioethers or thiols (Scheme 6). When ferf-butylhydroperoxide (TBHP) was used as an oxidant, tetrahydrothiophene (THT) was oxidized much faster with 5 than in the control experiment without 5. More importantly, such sulfoxidation could be performed with 5 as catalyst using ambient air as oxidant. However, formation of the desired product dipropylsulfane (PrSSPr) was very slow, and a 41% yield was obtained after 30 days at 45°C. 

Pd nanoparticles supported on PANI-NFs are efficient semi-heterogeneous catalysts for Suzuki coupling between aryl chlorides and phenylboronic acid, the homocoupling of deactivated aryl chlorides, and for phenol formation from aryl halides and potassium hydroxide in water and air [493], PANl-NF-supported FeCl3 as an efficient and reusable heterogeneous catalyst for the acylation of alcohols and amines with acetic acid has been presented [494]. Vanadate-doped PANI-NFs and PANI-NTs have proven to be excellent catalysts for selective oxidation of arylalkylsulfides to sulfoxides under nuld conditions [412]. Heterogeneous Mo catalysts for the efficient epoxidation of olefins with ferf-butylhydroperoxide were successfully synthesized using sea urchin-Uke PANI hollow microspheres, constructed with oriented PANI-NF arrays, as support [495]. Pt- and Ru-based electrocatalyst PANI-NFs—PSSA—Ru—Pt, synthesized by the electrodeposition of Pt and Ru particles into the nanofibrous network of PANI-PSSA, exhibited an excellent electrocatalytic performance for methanol oxidation [496]. A Pt electrode modified by PANI-NFs made the electrocatalytic oxidation reaction of methanol more complete [497]. Synthesis of a nanoelectrocatalyst based on PANI-NF-supported... 

Nitro derivatives of a variety of heteroaromatic compounds enter the VNS reactions with alkyl hydroperoxide anions to produce the expected hydroxylation products [41, 137-139]. For instance, the VNS hydroxylation of 2-chloro-5-nitropyridine with ferf-butylhydroperoxide was shown to give 2-chloro-5-nitro-6-hydroxypytidine that exists in its tautomeric form of pyridone [41] (Scheme 44). It should be stressed that the SNAr of chlorine located in the highly activated position 2 was not competing with the VNS. 

Yen et al. (2001) utilized the fluorescent dye 2 ,7 -dichlorofluorescin diacetate to measure the generation of reactive oxygen species in human umbilical vein endothelial cells. 17P-Oestradiol (54 /jM) pretreatment for 18 h or direct co-incubation significantly suppressed both ferf-butylhydroperoxide-and oxidised LDL-induced stimulation of the generation of reactive oxygen species. 

Glycogen breakdown induced by concentration above 0.2 mM H2O2 and ferf-butylhydroperoxide is due to a five fold increase in the ratio active glycogen phosphorylase a to inactive phosphorylase b (Heinle 1982, 1989). Concomitantly, ATP is decreased by about 50 % whereas the ATP/ADP ratio is decreased from about 2.3 (as found in fresh arterial tissue) to approximately 1.2. With respect to alterations of contractility, it was found that at concentrations of about 0.3 mM the peroxides were able to induce contraction in relaxed arterial rings (Heinle 1984). This indicates that cytosolic levels of calcium ions are increased under these conditions. Lower peroxide concentrations did not cause contraction. However, even at concentrations of 10 pM, potentiated contraction enhancement was found when the contractile apparatus was simultaneously activated, e.g., by depolarisation. This finding can be interpreted as a facilitative effect of the hydroperoxides on cytosoUc calcium release. The linolenic acid peroxide as synthesised in the reaction with soy bean lipoxidase revealed similar effects on contractility in concentrations up to 20 pM. 

The excellent enantioselectivities generally achieved with titanium tartrate-catalyzed epoxidation of allylic alcohols with ferf-butylhydroperoxide was exploited, for example, for the preparation of (2S,3S)- and (2/ ,3f )-[2,3- H2]oxiranes (72), two valuable chiral building blocks (Figure 11.28). By using a slightly modified Sharpless procedure, ( )-3-triphenylsilyl-2-[2,3- H2]propenol (20) was converted into the (S,S)- and (/ ,/ )-forms, respectively, of 3-triphenylsilyl[2,3- H2]glycidol (71). The hydroxylmethyl substituent... 

---