Decomposition of 2-[4-(2-chloro-1,1-dimethylethyl)phenyl]-propan-2-yl hydroperoxide catalyzed by sulfuric acid

The decomposition of 2-[4-(2-chloro-1,1-dimethylethyl)phenyl]propan-2-yl hydroperoxide in acetone catalyzed by H₂SO₄ affords 4-(2-chloro-1,1-dimethylethyl)phenol. The kinetics of this reaction at 56°C was studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1612–1613, August, 1999.     

Novel synthesis of triblock PDMS-PS-PDMS copolymers

Benzyl 6-(2′-pentamethyldisiloxanyl ethyl)-ortho-tolyl ketone (I) was prepared by a ruthenium-catalyzed Murai reaction of benzyl ortho-tolyl ketone with vinyl pentamethyldisiloxane. The reaction of I with a mixture of styrene and a catalytic amount of picoline Cu(II) acetate yielded the telechelic polystyrene α,ω-bis(2-pentamethyl-disiloxanyl ethyl)polystyrene (III). The acid-catalyzed equilibration polymerization of octamethylcyclotetrasiloxane into the Si O Si bonds of telechelic III yielded the polydimethylsiloxane-polystyrene-polydimethylsiloxane triblock soft–hard–soft copolymer. The molecular weights of the copolymers were studied by ¹H NMR end-group analysis and gel permeation chromatography. The thermal properties and morphology of IV were examined by differential scanning calorimetry and transmission electron microscopy (TEM). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 482–488, 2000     

ZnCrO_x/HZSM-5催化合成气直接转化制异构烷烃

分别采用共沉淀法和水热法制备了ZnCrO_x复合金属氧化物和HZSM-5沸石,通过物理混合得到双功能催化剂,实现了合成气一步高选择性制备异构烷烃。采用XRD、TEM、氮吸附和NH3-TPD等技术对催化剂进行了表征,考察了双功能催化剂中HZSM-5沸石组分硅铝比以及ZnCrO_x/HZSM-5质量比(OX/ZEO mass ratio)对合成气催化转化反应性能的影响。结果表明,随着HZSM-5硅铝比的增加,催化剂酸密度下降,CO转化率略有下降,产物中C5+选择性显著提高,异构烷烃比例不断增加。此外,在保证CO转化率的前提下提高双功能催化剂中ZnCrO_x组分的比例,产物中C5+的选择性也显著上升。在400℃、2.0 M Pa、进料空速(GHSV)为3600 mL/(h·gcat)的条件下,合成气(H2/CO(volume ratio)=2)转化率达到35%,C5+选择性超过44%,且C5+中异戊烷比例高达65%。     

Direct synthesis of carbonyl compounds from THP ethers with IBX in the presence of β-cyclodextrin in water

Water, an environmentally friendly reaction medium, has been utilized for the oxidative deprotection of tetrahydropyranyl ethers 1 with IBX at room temperature in the presence of β-cyclodextrin to give the corresponding carbonyl compounds 2.     

Solid phase deprotection of 2-nitrobenzenesulfonamides: synthesis of simple 2-(alkylamino)-pyrroles

The 2-nitrobenzenesulfonamide cleavage using a solid-phase thiophenolate reagent gives simple 2-(alkylamino)-pyrroles without the presence of the competing nucleophilic substitution product.     

An Efficient Cleavage of 1,3-Dioxolane Using ZnCl2/THF/H2O

Selective reactions on a functional group of polyhydroxy compounds are extremelyuseful in organic synthesis, especially in the field of carbohydrate and nucleosidechemistry. Indirect methods for the selective reaction on a functional group ofpolyhydroxy compounds involve the use of protective groups. In order to utilize thismethodology efficiently, selective protection and deprotection of ceftain hydroxy groupswithin the polyhydroxy compound are required.Ketal formation is most commonly used f…