And adamantanes

Protonation of formic acid similarly leads, after the formation at low temperature of the parent carboxonium ion, to the formyl cation. The persistent formyl cation was observed by high-pressure NMR only recently (Horvath and Gladysz). An equilibrium with diprotonated carbon monoxide causing rapid exchange can be involved, which also explains the observed high reactivity of carbon monoxide in supera-cidic media. Not only aromatic but also saturated hydrocarbons (such as isoalkanes and adamantanes) can be readily formylated. 

A l-Iiter, three-necked, round-bottom flask is equipped with a mechanical stirrer, a thermometer immersed in the reaction mixture, a dropping funnel, and a gas vent. In the flask is placed a mixture of 96% sulfuric acid (25.5 ml, 470 g, 4.8 mole), carbon tetrachloride (100 ml), and adamantane (13.6 g, 0.10 mole), and the mixture is cooled to 15-20° with rapid stirring in an ice bath. One milliliter of 98% formic acid is added and the mixture is stirred until the evolution of carbon monoxide is rapid (about 5 minutes). A solution of 29.6 g (38 ml, 0.40 mole) of t-butyl alcohol in 55 g (1.2 mole) of 98-100% formic acid is then added dropwise to the stirred mixture over 1-2 hours, the temperature being maintained at 15-20°. After stirring for an additional 30 minutes, the mixture is poured onto 700 g of ice, the layers are separated, and the aqueous (upper) layer is extracted three times with lOO-ml portions of carbon tetrachloride. The combined carbon tetrachloride solutions are shaken with 110 ml of 15 A ammonium hydroxide, whereupon ammonium 1-adamantanecarboxylate forms as a crystalline solid. This precipitate is collected by filtration through a fritted glass funnel and washed... 

Hurt AC, lanneUo P, Jachno K, Komadina N, Hampson AW, Barr IG, McKimm-Breschkin JL (2006) Neuraminidase inhibitor-resistant and -sensitive influenza B viruses isolated from an untreated human patient, Antimicrob Agents Chemother 50 1872-1874 Hurt AC, Selleck P, Komadina N, Shaw R, Brown L, Barr IG (2007) Susceptibility of highly pathogenic A(H5N1) avian influenza viruses to the neuraminidase inhibitors and adamantanes. Antiviral Res 73 228-231... 

Adamantane (A) and adamantan-4-one (B) were specifically hydroxylated at the quaternary C-1 by cytochrome P450j, to produce C and D. In contrast, the eukaryotic cytochrome P450lm2 formed in addition to the C-2 compound from adamantane, and both 5-hydroxy-adamantan-l-one (D) and the 4-a fi-hydroxyadamantan-l-one (E) from adamantan-4-one (Figure 3.18b) (White et al. 1984). 

P450 is able to hydroxylate the -CHj group of the quaternary methyl group of 5,5-difluorocamphor (Figure 7.45a) to the 9-hydroxymethyl compound (Fble and Dawson 1984), and both adamantane and adamantan-4-one at the -CH quaternary carbon atom (Figure 7.45b) (White et al. 1984). 

Thermodynamic data suggest the possibility of forming structure H-hydrates in gas and oil reservoirs and industrial installations. Hydrates formed with methane and adamantane have been found in situ in Mobile Bay in the Gulf of Mexico [1202]. 

Some cage compounds such as double decker - and adamantane-type compounds are synthesized by bridging appropriate units containing group 14 metal halides with S2 dianion as shown in Scheme l.21 24 The double decker -type compounds, (R2M2E2)2E2 (M = Si, Ge, E = S, Se), isomerize to the corresponding adamantane-type compounds by thermolysis.21,22... 

Recently Togni et al. [19] focussed on the preparation of asymmetric dendrimer catalysts derived from ferrocenyl diphosphine ligands anchored to dendritic backbones constructed from benzene-1,3,5-tricarboxylic acid trichloride and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (e.g. 11, Scheme 11). In situ catalyst preparation by treatment of the dendritic ligands with [Rh(COD)2]BF4 afforded the cationic Rh-dendrimer, which was then used as a homogeneous catalyst in the hydrogenation reaction of, for example, dimethyl itaconate in MeOH. In all cases the measured enantioselectivity (98.0-98.7%) was nearly the same as observed for the ferrocenyl diphosphine (Josiphos) model compound (see Scheme 11). 

Kollner et al. (29) prepared a Josiphos derivative containing an amine functionality that was reacted with benzene-1,3,5-tricarboxylic acid trichloride (11) and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (12). The second generation of these two types of dendrimers (13 and 14) were synthesized convergently through esterification of benzene-1,3,5-tricarboxylic acid trichloride and adamantane-1,3,5,7-tetracarboxylic acid with a phenol bearing the Josiphos derivative in the 1,3 positions. The rhodium complexes of the dendrimers were used as chiral dendritic catalysts in the asymmetric hydrogenation of dimethyl itaconate in methanol (1 mol% catalyst, 1 bar H2 partial pressure). The enantioselectivities were only... 

Raag, R. and Poulos, T. L. (1991) Crystal structures of cytochrome complexed with camphane, thiocamphor and adamantane factors controlling P450 substrate hydroxylation. Biochemistry 30, 2674-2684. 

Figure 11.3 Molecular structure of the multicyclic compounds cubane, tetrahydrodicyclopenta-diene and adamantane...

As stoich. [Ru(0)((N 0)p7CH3CN it oxidised primary alcohols to aldehydes, secondary alcohols to ketones, alkenes to aldehydes, tetrahydrofuran to y-butyrolactone. Styrene, cis- and tran -stilbenes gave benzaldehyde and adamantane gave 1-adamantol exclusively, while cyclohexanol gave cyclohexanone, suggesting that the complex is an effective oxidant for unactivated C-H bonds [636]. Immobilisation of the catalyst within Nation films on a basal plane pyrohtic graphite electrode was achieved, but the... 

K[RuCl3(saloph)] (saloph=fcix(salicylaldehyde)o-phenylenediamine) is made from K3[Ru(H30)Cl3] and the ligand. As [RuCl3(saloph)] /03/water-dioxane it oxidised cyclohexane and adamantane. The intermediacy of Ru(lV) and Ru(V) complexes was proposed [796]. 

The self-assembly of an imprinted layer on the surface of a transducer was realized through the adsorption of the template on gold, Si02, or ln02 surfaces followed by treatment with an alkylthiol or organosilane (Hirsch et al. 2003). The first example of this type of sensor was reported in 1987 by Tabushi and coworkers (1987). Octadecylchlorosilane was chemisorbed in the presence of n-hexadecane onto tin dioxide or silicon dioxide for electrochemical detection of phylloquinone, menaqui-none, topopherol, cholesterol, and adamantane. Another MlP-based sensor was... 

Itoh et al. used Cu yd-diketiminato complexes with general formula 4, and their reactivity has been described as a functional model for pMMO (particulate methane monooxygenase). Initially, the Hgands were reacted with both Cu and Cu precursors, with a variety of species formed, depending on the specific conditions employed [111, 112]. It was then shown that both Cu and Cu complexes ultimately led to bis(/z-oxo)(Cu )2 species upon reaction with O2 and H2O2, respectively. Use of these Cu complexes as the pre-catalysts for the oxidation of alkanes (cyclohexane and adamantane) in the presence of H2O2 resulted in low yields ( 20%). 

Furthermore, di- and polychlorination are much less prevalent. Dicarboxylic acids are predominantly chlorinated in the middle of the chain,99 and adamantane and bicy-clo[2.2.2]octane at the bridgeheads100 by this procedure. The reasons for the high to - 1 specificity are not clearly understood.101 Alkyl bromides can be regioselectively chlorinated... 

Alkylcyclohexanes, cycloheptane, and cyclooctane were also transformed into the esters of the corresponding tertiary cyclohexanecarboxylic acids in the presence of the superelectrophile CBr4—2AlBr3 in good yields.314 315 Such organic superacids generated from polyhalomethanes with aluminum halides are capable of promoting the selective and effective carboxylation of linear alkanes (propane, butane) and adamantane as well.316... 

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