Photochemical preparation of 1,3,5,7-tetracyanoadamantane and its conversion to 1,3,5,7-tetrakis(aminomethyl)adamantane

New adamantane derivatives 1 and 2 that bear functionalized one-carbon extensions at all four bridgehead positions have been prepared. Radical nucleophilic substitution (S(RN)1) reaction of 1,3,5,7-tetrabromoadamantane with cyanide produces 1,3,5,7-tetracyanoadamantane (1), which was reduced with borane reagents to 1,3,5,7-tetrakis(aminomethyl)adamantane (2). Improvements in the preparation of 1,3,5,7-tetrahaloadamantanes (halogen = Br, Cl, I) are also reported. [structure--see text]     

Theoretical study of tricyclo[3,3,1,1]decane, tricyclo[3,3,1,1]decsilane molecules and their halogen derivatives, C10H12X4 and Si10H12X4 (X=F, Cl, Br, I)

The B3LYP/3-21G* ab initio molecular orbital method from the program package was applied to study tricyclo[3,3,1,1^3,7]decane and tricyclo[3,3,1,1^3,7]decsilane molecules and their halogen derivatives (1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decsilane, C₁₀H₁₂X₄ and Si₁₀H₁₂X₄ respectively). The optimized structures of these compounds were obtained. Ionization potentials, HOMO and LUMO energies, energy gaps, heats of formation, atomization energies and vibration frequencies were calculated. The calculations indicate that these molecules are stable and have T_d symmetry. Tricyclo[3,3,1,1^3,7]decsilane and its halogen derivatives (Si₁₀H₁₂X₄) are found to have higher conductivity than tricyclo[3,3,1,1^3,7]decane and its halogen derivatives (C₁₀H₁₂X₄). 1,3,5,7-Tetrafluorotricyclo[3,3,1,1^3,7]decane (C₁₀H₁₂F₄) and 1,3,5,7-tetrafluorotricyclo[3,3,1,1^3,7]decsilane (Si₁₀H₁₂F₄) were found to be the easiest compounds to form and the most difficult to dissociate of all 1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decsilane compounds, respectively.     

Spectroscopic response of ferrocene derivatives bearing a BODIPY moiety to water: a new dissociation reaction

Ferrocence and its derivatives have long been known to be a class of stable organometallic compounds, and their dissociation usually occurs under harsh conditions. Here we report a new type of ferrocene derivatives, 4,4-difluoro-8-ferrocenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene and 4,4-difluoro-2,6-diethyl-8-ferrocenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene, which surprisingly can hydrolyze under mild conditions. These two derivatives, initially developed as donor-acceptor probes for reactive oxygen species by incorporating the electron donor of ferrocene as a quencher into the fluorophore of BODIPY (boron dipyrromethene difluoride), barely emit fluorescence. Upon reaction with H(2)O under the irradiation of natural light at room temperature, however, both of the probes display a dramatic color change and fluorescence retrievement. Detailed experimental results reveal that the reaction of the probes with H(2)O leads to the removal of a cyclopentadiene unit and iron(II), yielding a BODIPY derivative that retains the other cyclopentadiene unit and shows a large fluorescence enhancement (over 100-fold). Moreover, the increase in fluorescence intensity is directly proportional to microamount of water, and the presence of both light and H(2)O is indispensable in the reaction, which makes the present system of great potential not only for determining water but also for forming a AND logic gate. Most importantly, the present mild dissociation reaction may give a new insight into the stability of ferrocene and its derivatives.     

Fluoropyrroles and tetrafluoroporphyrins

Photolysis of pyrrole-β-diazonium tetrafluoroborates gave β-fluoropyrroles. These were further converted to 1,3,5,7-tetrafluoroporphyrins, the first example of ring-fluorinated porphyrin derivatives.     

Theoretical predictions on pentaerythritol tetranitrate-based high energy density compounds

A novel family of pentaerythritol tetranitrate (PETN) derivatives based parent PETN skeleton were designed by introducing two energetic groups –NF₂ and –NO₂. Their electronic structure, heats of formation, detonation properties, impact sensitivity, and thermal stability were investigated by using density functional theory. The findings reveal that most of the title compounds have good detonation performance. The –NF₂ group played an important role in improving the densities, heats of detonation, and detonation properties of the designed molecules. The values of h₅₀ for almost all the PETN derivatives are higher than that of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. An analysis of bond dissociation energy suggests that the N-NO₂ bond tends to be a trigger bond in thermal decomposition. Taking both detonation properties and thermal stabilities into consideration, the three compounds may be selected as potential high-energy-density compounds.     

Structural,thermochemical and detonation performance of derivatives of 1,2,4,5-tetrazine and 1,4 <Emphasis Type="Italic">N</Emphasis>-oxide 1,2,4,5-tetrazine as new high-performance and nitrogen-rich energetic materials

In this study, density functional theory calculations are used to estimate enthalpy of sublimation, enthalpy of formation and crystal density of some important derivatives of 1,2,4,5-tetrazine and 1,4 N-oxide 1,2,4,5-tetrazine. These data were used for predicting their detonation properties including heat of detonation, detonation pressure, detonation velocity, detonation temperature, spark sensitivity, deflagration temperature and power of energetic using appropriate methods. The results show that the title compounds exhibit high positive solid-phase enthalpy of formation. It is found that detonation pressure and detonation velocity of these compounds are high because of the large values of crystal density and solid-phase enthalpy of formation. Detonation temperature and spark sensitivity of some derivatives are higher than octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine as one of the high-performance explosives.     

Density functional study of tricyclo[3,3,1,13,7]decane and tricyclo[3,3,1,13,7]decsilane and their halogen derivatives

The B3LYP/3‐21G* ab initio molecular orbital method from the Gaussian 94 computer program package was applied to study tricyclo[3,3,1,1^3,7]decane and tricyclo[3,3,1,1^3,7]decsilane molecules and their halogen derivatives (1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decsilane, C₁₀H₁₂X₄, and Si₁₀H₁₂X₄). The optimized structures of these compounds were obtained. Ionization potentials, HOMO and LUMO energies, energy gaps, heats of formation, atomization energies, and vibration frequencies were calculated. These calculations indicate that these molecules are stable and have T_d symmetry. Tricyclo[3,3,1,1^3,7]decsilane and its halogen derivatives (Si₁₀H₁₂X₄) are found to have higher conductivity than that of tricyclo[3,3,1,1^3,7]decane and its halogen derivatives (C₁₀H₁₂X₄). 1,3,5,7‐Tetraflourotricyclo[3,3,1,1^3,7]decane (C₁₀H₁₂F₄) and 1,3,5,7‐tetraflourotricyclo[3,3,1,1^3,7]decsilane (Si₁₀H₁₂F₄) were found to be the easiest compounds to form and the most difficult to dissociate of all 1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decsilane compounds, respectively. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 72: 189–198, 1999     

Selective ring opening reactions of 3,7-diarylsulfonyl-1,3,5,7-tetrazabicyclo[3.3.1] nonaries

The selective formation of 1,3,5,7-tetrazacyelooctanes from the title compounds is described. Exclusive cleavage of the IN-CH₂-N bonds at the bridge methylene is shown to be a facile process, thus providing a convenient route to tetrazacyclooctane derivatives.     

Direct Metalation of 1,3,5,7-Tetranitrocubane with Amides of Tin and Lead. Preparation and Chemistry of o-Nitrostannanes and o-Nitroplumbanes in the Cubyl Series(1)

Trialkyltin and trialkyllead amides react directly and remarkably easily with 1,3,5,7-tetranitrocubane to form mono- to tetrakis(trialkyltin)- and -(trialkyllead) tetranitrocubanes. These are all stable compounds. The X-ray crystallographic properties of some are given. The (trialkylstannyl)cubanes react with electrophiles such as bromine with unexpected cleavage of alkyltin bonds rather than cubyl-tin bonds. On the other hand, the (trialkylplumbyl)cubanes do ultimately undergo cubyl-lead bond cleavage. This provides a useful way to achieve substitution on the cubane nucleus and provides access to compounds such as 1,3,5,7-tetrabromo-2,4,6,8-tetranitrocubane. The lead derivatives of tetranitrocubane are also useful for making 1,2,3,5,7-pentanitrocubane and 1,2,3,4,5,7-hexanitrocubane.     

Some reactions of 1,3,5-Triaza-7-phosphaadamantane and its 7-Oxide

The synthesis of 1,3,5,7-triazaphosphocine and 1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane derivatives via nitration, nitrosation and acetylation of 1,3,5-triaza-7-phosphaadamantane and its 7-oxide is reported. A comparison of the reactions of the triazaphosphaadamantane with the analogous reactions of hexamine is made.     

Synthesis and Transformations of 1,3,5,7-Tetraazabicyclo[3.3.1]nonanes

Published data on the synthesis of 3,5-disubstituted 1,3,5,7-tetraazabicyclo[3.3.1]nonanes and their transformations into 1,3,5,7-tetraazacyclooctanes and 1,3,5-triazacyclohexanes are discussed.     

Double 1,3-dipolar cycloadditions of meso-ionic heterocycles with N-phenylmaleimide

3-Phenylsydnone and 2,4-diphenyl-3-methyloxazolium 5-oxide undergo double 1,3-dipolar cycloadditions with two molecules of N-phenylmaleimide to produce 4,8-iminobenzo[1,2-c:4,5-c′]dipyrrole-1,3,5,7-tetrone derivatives in a stereoselective manner.     

Effective synthesis of <Emphasis Type="Italic">N</Emphasis>-substituted 1,3,5-dithiazinanes by reactions of <Emphasis Type="Italic">N</Emphasis>-methyl-1,3,5-dithiazinane and 1,3,5-trithiane with aromatic amines

A novel procedure has been developed for selective synthesis of N-aryl-1,3,5-dithiazinanes, 1,2,6,7-tetrahydro-3,5,1,7-benzodithiadiazonine, and 6,7-dihydro-1,3,5,7-benzotrithiazonine by reactions of aniline derivatives with N-methyl-1,3,5-dithiazinane or 1,3,5-trithiane in the presence of transition and rare earth metal salts and complexes.     

Stereoisomers of 1,3,5,7-tetrahydroxy-1,3,5,7-tetraisopropylcyclotetrasiloxane: synthesis and structures in the crystal

The first synthesis of all four stereoisomers of 1,3,5,7-tetrahydroxy-1,3,5,7-tetraisopropylcyclotetrasiloxane, [i-PrSiO(OH)]4 (all-trans-, cis-cis-trans-, cis-trans-cis-, and all-cis-1), is presented. The starting compounds, all-trans-, cis-cis-trans-, cis-trans-cis-, and all-cis-1,3,5,7-tetraaryl-1,3,5,7-tetraisopropylcyclotetrasiloxanes, were prepared by the hydrolysis of the corresponding arylisopropyldichlorosilanes, i-PrArSiCl2 (Ar = Ph, p-tolyl), and subsequent separation of isomers. A combination of dephenylchlorination of tetraarylcyclotetrasiloxanes and the following hydrolysis proved to be an efficient method for the stereospecific transformation of aryl-substituted cyclotetrasiloxanes into (i-PrSiO(OH))4. For example, treatment of cis-trans-cis-1,3,5,7-tetraphenyl-1,3,5,7-tetraisopropylcyclotetrasilane with HCl and AlCl3, followed by hydrolysis in the presence of pyridine, resulted in the exclusive formation of cis-trans-cis-1 in 92% yield. The structures of cis-cis-trans-1, cis-trans-cis-1, and all-cis-1 were determined by X-ray crystallography. All isomers were found to construct unique packing structures by intermolecular hydrogen bonding; cis-trans-cis-1 composed an infinite antiladder structure, and cis-cis-trans-1 formed a sheetlike structure.     

Neue 1,6-Methano[10]annulen-Derivate durch Umlagerungsreaktionen der Trimethylsilyl-Gruppe

New Derivatives of 1,6-Methano[10]annulene by Rearrangement of Trimethylsilyl Groups Oxidation of derivatives of trimethylsilyl-substituted bicyclo[4.4.1]undeca-1,3,5,7-tetraenes 1–3 leads to 1,6-methano[10]annulenes. In the case of 2 and 3a , rearrangement of the trimethylsilyl group takes place. This rearrangement can be used to prepare 2,9-disubstituted 1,6-methano[10]annulenes.     

Cage strain in nitro-substituted 1,3,5,7-tetraazacubanes

Homodesmotic reactions were designed for the computation of strain energies (SE) for four nitro-substituted 1,3,5,7-tetraazacubane derivatives. Total energies of the optimized geometric structures at the DFT-B3LYP/6-31G* and DFT-B3LYP/6-311G** levels were used to derive the SE. The variation of SE with respect to the number of substituents is similar with both basis sets. The SE value is 237.32 kcal/mol at the B3LYP/6-311G** level for 2,4,6,8-tetranitro-1,3,5,7-tetraazacubane, which is unexpectedly much larger than that of its cubane analogue. The SE increases remarkably with more nitro groups being attached to the cage skeleton of tetraazacubane. The ‘bending’ of the bonds within the cubic skeleton attributes to the increase of strains as the attached number of nitro groups increases.     

Synthesis and solution structure of 3,5-dioxopimelic acid diesters--stable 1,3,5,7-tetracarbonyl derivatives

A variety of 3,5-dioxopimelic acid diesters, stable 1,3,5,7-tetracarbonyl derivatives, were prepared by catalytic condensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with methyl malonyl chloride. The keto-enol tautomerization of these compounds has been investigated by NMR spectroscopy. One keto and up to four enolic tautomers could be detected in chloroform solution and the influence of the substituents on the tautomeric equilibria has been studied.     

Bildung Siliciumorganischer Verbindungen. LV. Die Konformeren des 1,3,5,7-Tetrasila-bicyclo[3,3,1]nonans und 2,4,6,8,9-Pentasila-bicyclo[3,3,1]nonans

Formation of Organosilicon Compounds. LV. Conformeres of the 1,3,5,7-Tetrasilabicyclo [3,3,1] nonane and 2,4,6,8,9-Pentasila-bicyclo [3,3,1] nonane Two types of carbosilanes with a bicyclo [3,3,1] nonane structure are reported, derivatives of 1,3,5,7-Tetrasila-bicyclo-[3,3,1] nonane (a) and of 2,4,6,8,9-Pentasila-bicyclo [3,3,1] nonane (b) with an inverse structure in respect to the Si- and C-atoms. By means of NMR-investigations the structure can be determined. Derivatives of (a) are present in the Si₄C₁₁H₂₈ with fully methylated Si-atoms, the 1,5 dichloro-1,3,5,7-tetrasila-bicyclo [3,3,1] nonane and Si₄Cl₆C₅H₁₀ with fully chlorinated Si-atoms with twofold boat conformation. In the derivatives of type (b) as Si₅H₁₀C₄H₆ with hydrogenated Si-atoms as well as in 9,9-dichloro-2,4,6,8,9-pentasila-bicyclo [3,3,1] nonane a change in conformation is observed, whereas a rigid chair conformation is found for both rings in the Si-chlorimated derivative Si₅Cl₁₀C₄H₁₀. A comparison of atom-resp. H? H distances in cyclohexane and 1,3,5-Trisilacyclohexane gives evidence that the boat conformation is more preferable for the 1,3,5-Trisilacyclohexane than for cyclohexane due to larger H? H-distances (caused by Si? C-distances).     

Aminomethylation of pemoline

Aminomethylation of pemoline with primary amines has given the corresponding oxazolo[3,2-a]-1,3,5-triazines or oxazolo[3,2-a]-1,3,5,7-tetrazocines. When secondary amines were used, the 5-amino- or 3,5-bis(aminomethyl) derivatives were obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1670–1674, December, 1990.The authors thank A. V. Dogadin for obtaining and discussing the PMR spectra.