1.3.5- tri-tert-butylbenzene

In triethylamine instead of benzene the reaction products are completely different, and are indicative of a homolytic process involving an initial electron transfer from triethylamine followed by a hydrogen atom transfer. Scheme 10-68 gives the major products, namely 1,3,5-tri-tert-butylbenzene (10.36, 20%), the oxime 10.39 (18%), formed from the nitroso compound 10.38, and the acetanilide 10.37 (40%). ESR and CIDNP data are consistent with Scheme 10-68. In their paper the authors discuss further products which were found in smaller yields. 

Two grams of a solution containing 5% each of two linear paraffins and an internal standard 1,3,5-tri-tert-butylbenzene dissolved in 1,3,5-tri-isopropylbenzene was added to lg H-ZSM-5. Equilibrium sorption was established within a few hours and remained constant for 24 hours. 

To investigate whether the mechanism proceeds by inner-sphere or outer-sphere electron transfer, other catalysts of the type [Fe ( / -C5H4C02 )(/7 -arene)][PF6] were synthesized with bulky arenes such as 1,3,5-tris-tert-butylbenzene and C6(CH2CH2p-C6H40H)6. The rate constants were found to be one to two orders of... 

The partial hydrogenation of 1,3,5-trisubstituted benzenes gives only a single cyclohexene product. When the substituents are large, as with 1,3,5-tri-tert-butylbenzene (6), selective formation of the cyclohexene, 7, occurs even over unmodified Pt/C and Rh/C catalysts when the reaction is run in heptane at room temperature and atmospheric pressure. With Pt/C, 45-50% selectivity toward the cyclohexene was found at 50% conversion while with Rh/C 60-65% selectivity was obtained at 60% conversion (Eqn. 17.5). ... 

The adsorption experiments were carried out as follows 1 mmol substrate was added to 10 ml of 1,3,5-triisopropylbenzene containing 100 mg 1,3,5-tri-tert-butylbenzene (internal standard) and 1 g CrAPO-5. The mixture was heated (80... 

Practical determination of the porosities often suffers some difficulties. The most common method for determining the total porosity is the injection of a non-retained, pore-penetrating tracer substance (grey and small black circles in Fig. 2.5). In normal phase chromatography, toluene or 1,3,5-tri-tert-butylbenzene are often used, while in reversed phase chromatography uracil is the component of choice. 

Figure 4. A) Conversion of (S)-6-MeCL as a function of time and B) development of MW during the ITC polymerisation of 6-MeCL. Reaction conditions Shvo catalyst (0.03 mmol), Novozym 435 (33 mg), (S)-6-MeCL (2.5 mmol), BA (0.05 mmol), DMP (0.25 mmol), and 1,3,5-tri tert-butylbenzene (0.20 mmol, internal standard) were stirred in toluene (2.5 mL) at 70 °C under Ar.

Substituted tert-butylbenzenes behave likewise The complete dealkylation of tert-butylbenzenes under these conditions is due to benzene protonation. In the weaker acid system HF—TaFj, protonated 1,3-di-and 1,3,5-tri-tert-butylbenzenes are formed from tert-butylbenzene, but the (CH3)jC+ cation does not appear... 

The ferf-butyl cations liberated from compounds Ar—tert- Bu, upon ipso reaction of a proton, may also react again with the aromatic compound from which they stemmed. If this course is taken, the te/7-butyl groups are ultimately bound to the aromatic nucleus with a regioselectivity that is dictated by thermodynamic control. Figure 5.4 shows how in this way 1,2,4-tri-ferf-butylbenzene is smoothly isomerized to give 1,3,5-tri-fcrt-buty 1-benzene. 

In their investigations of benzene isomerization reactions Wilzbach and Kaplan 52> established that a substituted tricyclo [2.1.1.05 6] hex-2-ene (a benzvalene) 69 is an intermediate in the photoconversion of 1,2,4-tri-tert-butylbenzene (70) and the 1,3,5-isomer (71). They also demonstrated that the irradiation of either 70 or 71 at 2537A yields a photostationary mixture in which the principal component is prismane (72) produced from the Dewar benzene 73. These authors pictured the reaction sequence as shown below. 

Radical cations of hexa-, penta- and tetramethylbenzenes, as well as 1,3,5-tri-and 1,4-di-tert-butylbenzenes have been det ted by ESR in a flow system after inter-.nction with cobalt triacetate in CF3COOH The radical cations of polyfluorinated aromatic compounds proved to be quite stable. Hexafluorobenzene interacted with O2 AsFg in WFj to yield the salt of the hexafluorobenzene radical cation CgF AsFg Octafluoronaphthalene, deca-fluorobiphenyl, hexa-, penta- and 1,2,4,5-tetrafluorobenzenes yield radical cations... 

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