Indanes reactions

Neither C5- nor C6-cyclization involve carbonium-ion intermediates over platinum metal. The rates of the -propylbenzene - indan reaction (where the new bond is formed between a primary carbon atom and the aromatic ring) and the n-butylbenzene- 1-methylindan reaction (which involves a secondary carbon atom) are quite similar (13). Furthermore, comparison of the C6-cyclization rates of -butylbenzene and n-pentylbenzene (forming naphthalene and methylnaphthalene, respectively) over platinum-on-silica catalyst shows that in this reaction a primary carbon has higher reactivity than a secondary carbon (Table IV) (29). Lester postulated that platinum acts as a weak Lewis acid for adsorbed cyclopentenes, creating electron-deficient species that can rearrange like carbonium ions (55). The relative cyclization rates discussed above strongly contradict Lester s cyclization mechanism for platinum metal. 

Ninhydrin (also named 1 2 3-triketoindane or 1 2 3-triketohydrindene hydrate) is prepared most simply from the inexpensive phthahc anhydride (I). The latter is condensed with acetic anhydride In the presence of potassium acetate to give phthalylacetlc acid (II) reaction of the latter with sodium methoxide in methanol yields 1 3-indanedionecarboxyhc acid, which is decomposed upon warming with dilute hydrochloric or sulphuric acid to indane-1 3-dione (or 1 3-diketohydrindene) (HI). Selenium dioxide oxidation of (III) afibrds indane-1 2 3-trione hydrate (ninhydrin) (IV). 

During the high-temperature operations, intermolecular hydrogen transfer reactions occur, transforming some indene to indane. The high indane concentration in the resin feedstock causes low yield and poor quality in the polymerization process. The indene loss can be reduced by decreasing the temperature and the residence time during distillation. 

Fluonnation and skeletal transformation of fluorinated cycloalkanes occurs in the reaction with antimony pentafluoride at high temperature [777] In the case of perfluorinated benzocyclobutanes, an unexpected alicyclic ring cleavage has been observed Perfluorinated alkyl benzocyclobutanes, when treated with antimony pentafluoride, ean be converted to perfluorinated styrenes and then transformed to perfluorinated indans [77S, 779]... 

The catalytic system used in the Pacol process is either platinum or platinum/ rhenium-doped aluminum oxide which is partially poisoned with tin or sulfur and alkalinized with an alkali base. The latter modification of the catalyst system hinders the formation of large quantities of diolefins and aromatics. The activities of the UOP in the area of catalyst development led to the documentation of 29 patents between 1970 and 1987 (Table 6). Contact DeH-5, used between 1970 and 1982, already produced good results. The reaction product consisted of about 90% /z-monoolefins. On account of the not inconsiderable content of byproducts (4% diolefins and 3% aromatics) and the relatively short lifetime, the economics of the contact had to be improved. Each diolefin molecule binds in the alkylation two benzene molecules to form di-phenylalkanes or rearranges with the benzene to indane and tetralin derivatives the aromatics, formed during the dehydrogenation, also rearrange to form undesirable byproducts. 

These particular properties of chloroalanes favor the formation of simple Lewis acid-base adducts, as was observed for the reaction of R2AICI with Sb(Tms)3 (R = Et, f-Bu). In contrast, reactions of the analogous gallanes and indanes yielded the desired heterocycles. The same tendencies were observed in reactions of R2MCI (M = Al, Ga, In R = Et, i-Bu) with P(Tms)3 and As(Tms)3. The gallane and indane react under formation of the expected M—E heterocycles [71], while the corresponding alanes yield the simple adducts... 

Further studies were carried out with halocarbene amides 34 and 357 Although again no direct spectroscopic signatures for specifically solvated carbenes were found, compelling evidence for such solvation was obtained with a combination of laser flash photolysis (LFP) with UV-VIS detection via pyridine ylides, TRIR spectroscopy, density functional theory (DFT) calculations, and kinetic simulations. Carbenes 34 and 35 were generated by photolysis of indan-based precursors (Scheme 4.7) and were directly observed by TRIR spectroscopy in Freon-113 at 1635 and 1650 cm , respectively. The addition of small amounts of dioxane or THF significantly retarded the rate of biomolecular reaction with both pyridine and TME in Freon-113. Also, the addition of dioxane increased the observed lifetime of carbene 34 in Freon-113. These are both unprecedented observations. 

After reaction, any solid residue was filtered off and the liquid product was separated by distillation into a bottoms product and a distillate that included unreacted Tetralin and low-boiling products from both the coal and the Tetralin. As tetralin breaks down under dissolution conditions to form mainly the tetralin isomer 1-methyl indan, naphthalene and alkyl benzenes (4) it was assumed that no compound with a higher boiling point than naphthalene was formed from the solvent, and the distillation to recover solvent was therefore continued until naphthalene stopped subliming. Some residual naphthalene remained in the bottoms product its mass, as determined from nmr and elemental analysis, was subtracted from the mass of bottoms product recovered and included in the amount of distillate recovered. It was assumed that all naphthalene present came from the Tetralin, not the coal. However, as the amount of tetralin reacted was 10 times the amount of coal this assumption appears reasonable. 

Tetralin has been shown to undergo thermal dehydrogenation to naphthalene and rearrangement to methyl indan in either the absence or presence of free radical acceptors [ 1, 2]. The presence of free radical acceptors usually accelerates the rearrangement reaction. Even with alkylated Tetralins>... 

The basic reactions of Tetralin and derivatives have been extended to the use of 1-13C labels and 1,2-dihydronaphthalene, with and without a source of free radicals. The studies with Tetralin were monitored equally well with C-NMR and GLC techniques. The rate constant for the conversion of Tatralin to methyl indan in the presence of dibenzyl at 450°C was 6.4 x 10 min i which is consistent with that previously reported [2]. 

Dihydronaphthalene (DHN) is frequently assumed to be an intermediate in hydrogen transfer reactions. While this appears reasonable, efforts to detect and/or measure this intermediate have never been very successful. Assuming that DHN is present, we have briefly explored its role in hydrogen transfer and methyl indan formation. 

Kwok, E.S.C., Atkinson, R., Arey, J. (1997) Kinetic of the gas-phase reactions of indan, indene, fluorene, and 9,10-dihydroanthracene with OH radicals, NOs radicals, and 03. Int. J. Chem. Kinet. 29, 299-309. 

Group 13/15 compounds have a long-standing history in inorganic chemistry and have been known for almost two centuries. First reports on such compounds go back to 1809, when Gay Lussac synthesized F3B4—NH3,1 the historical prototype of a Lewis acid-base adduct, by reaction of BF3 and NH3. Since this initial study, numerous Lewis acid-base adducts of boranes, alanes, gallanes and indanes MX3, MF13 and MR3 (M = B, Al, Ga, In X = F, Cl, Br, I R = alkyl, aryl) of the type R3M <- ER 3 (E = N, P, As) (Type A) have been synthesized and... 

H3A1 NMe3,53 whose structure has been determined by X-ray diffraction.54 Since these initial studies, comparable reactions were observed for alanes, gallanes and indanes R3M (M = Al, Ga, In R = H, halogen) with amines and phosphines, yielding bis-amine, bis-phosphine and mixed amine/ phosphine adducts. Figure 13 presents the different coordination modes that have been observed so far. 

In 1988, Cowley et al. demonstrated this specific reaction to be also useful for the preparation of heterocyclic stibinogallanes and -indanes.77a,77b [Cl2GaSb(/-Bu)2]3 44 and [/-Bu2Sb(Cl)In-p-Sb(/-Bu)2]2 57 were obtained by reaction of MC13 and /-Bu2SbSiMe3 (see also Scheme 5) and structurally characterized by single crystal X-ray diffraction. In 1996, we and Wells... 

Scheme 7. Synthesis of heterocyclic stibinogallanes and -indanes by dehalosilylation reaction.

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