1-Phosphabicyclo[3,3,1]nonan

1-Phosphabicyclo[3,3,1]nonane The synthesis of 1-phosphabicyclo[3,3,1]nonane II by free-radical cyclization of the primary phosphine (CH₂?CH? CH₂)₂CH? CH? PH₂ I is described. IR data favour a twin-chair conformation of II and its derivatives with oxygen V and sulphur VI . The magnitudes of the ³¹P NMR chemical shifts and of the phosphorus-hydrogen spin-spin coupling constants (¹J_PH, ²J_PH) are compared with values of aliphatic phosphines R₃P. The degree of substitution of CO from Ni(CO)₄ by II and other chemical evidences suggest a TOLMAN ligand cone angle of about 120–125°.     

The synthesis of 1,2-diazabicyclo[3,3,1]nonane and 1,9-diazabicyclo-[4,3,0]nonane. iv

The new bicyclic systems 1,2-diazabicyclo[3,3,1]nonane and 1,9- diazabicyclo [4,3,0]nonane have been synthesized from 2- (and 3-) piperidineacetic acid via their nitroso-derivatives, and 3-oxo-1,2 diazabicyclo [3,3,1]nonane and 8-oxo-1,9-diazabicyclo[4,3, 0]nonane.For Part III, see [3].     

Synthesis and conformational analysis of 6-substituted-3-azabicyclo[3,3,1]nonanes

6-hydroxy substituted 3-tosyl-3-aza-bicyclo[3,3,1]nonan-9-ones 2a and 2b are obtained directly via acrolein addition to N-Ts-piperidine pyrrolidine enamine. From ¹H NMR spectral data of a series of derivatives a preferred twin-chair conformation for the adducts is indicated. This conclusion is supported both by studies on the elimination of the 6-OR group and on the reduction of the C₉-oxo function. Anomalous formation of sultone 10 is also noted.     

Bildung siliciumorganischer Verbindungen. LX. Die Kristall- und MolekülStruktur des Heptamethyl-tetrasila-[2,2,2]-barrelans Si4C11H28

Formation of Organosilicon Compounds. LX. Crystal and Molecular Structure of Heptamethyl-tetrasila-[2,2,2]-barrelan Si₄C₁₁H₂₈ 1,1,3,5,5,7,7-Heptamethyl-1,3,5,7-tetrasila-[2,2,2]-barrelan Si₄C₁₁H₂₈ crystallizes in the orthorhombic space group Pn2₁a with a = 12.293, b = 9.903, c = 14.018 Å and Z = 4 formula units. The six-membered rings have the skew-boat conformation with a torsion angle of 23.5° with respect to the molecular axis. The skew-boat conformation results from the interaction of CH₃- and CH₂- groups. The mean value for the bond length is Si? C = 1.881 Å. The distances Si? CH₂ = 1.873 Å are somewhat smaller than the others (1.887 Å).     

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     

Conformational analysis of 3-borabicyclo[3.3.1]nonane derivatives

Conformations of 3-borabicyclo[3.3.1]nonane derivatives have been studied by means of ¹H and ¹³C NMR spectroscopy. With the aid of the coupling constants ³J(HH) and ¹³C chemical shifts it has been shown that all the derivatives of 3-borabicyclo[3.3.1]nonane with the trigonal boron atom studied are in a flattened double-chair conformation. In 3-borabicyclo[3.3.1]nonane derivatives with the tetra-coordinated boron atom and substituents at the 7α-position, the chair-boat conformation predominates, the boat conformation being characteristic of the cyclohexane ring; exceptions are the compounds with the internal donor—acceptor bond between the boron atom an 7α-substituent.     

Die Strukturen der 1,3,5-Trisilacyclohexan-Eisendicarbonyl-cyclopentadienylkomplexe C3H6Si3Cl5Fe(CO)2πcp und C3H6Si3Cl4(Fe(CO)2πcp)2

Structures of the l,3,5-Trisilacyclohexane-Iron Dicarbonyl-cyclopentadienyl Complexes and C₃H₆Si₃Cl₅Fe(CO)₂πcp and C₃H₆Si₃Cl₄(Fe(CO₂)πcp)₂ Trisilapentachlorocyclo-hexyl-dicarbonylcyclopentadienyliron C₃H₆Si₃Cl₅Fe(CO)₂πcp 1 and Trisilatetrachlorocyclohexyl-bis(dicarboncyclopentadienyliron)C₃H₆Si₃Cl₄(Fe(CO)₂πcp)₂ 2 are 1,3,5-Trisilacyclohexane complexes substituted by dicarbonylcyclopentadienyliron at one and two silicon atoms of the six-membered ring, respectively. The crystal and molecular structures were determined from single crystals ( 1 ; space group P2₁/a (No. 14); a = 1100.5 pm; b = 2033.9 pm; c = 843.3pm; β = 98.58°; Z = 4; MoKα-radiation; 3142h k l; R = 0.036. 2 ; space group P1 ; (No. 2); a = 1231.1 pm; b = 1267.3 pm; c = 1045.9 pm; α = 113.23°; β = 83.93°; γ = 115.00°; Z = 2; Mokα-radiation; 4196 h k 1; R = 0.065). In both complexes the six-membered rings of the carbosilane ligands are in skew-boat conformation. The bond lengths Fe? Si are 226.4 pm and 228.1 pm, respectively. The distances Si? C and Si? Cl are 186 pm and 206 pm in 1 and 187 pm and 209 pm in 2 . Their different lengths depend on the position in the ligand system and can be explained with the concept of bond orders.     

Resolution and Crystal Structure of 9α-(3-Azabicyclo[3,3,1]nonanyl)- 2''-cyclopentyl-2''-hydroxyl-2''-thienylacetate

The crystal structure of 9α-(3-azabicyclo[3,3,1]nonanyl)-2'-cyclopentyl-2'-hydro-xyl-2'-thienylacetate (C16H27NO3S, Mr = 349.48) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic, space group P212121 with a = 14.937(3), b = 8.1673(16), c = 15.423(3) (A), V = 1881.5(6) (A)3, Z = 4, Dc =1.234 g/cm3, μ = 0.188 mm-1, F(000) = 752, the final R = 0.0468 and wR = 0.1251. The bicyclo[3,3,1]nonane ring system adopts the most favored twin-chair conformation. The crystal structure shows the existence of intramolecular O-H…O hydrogen bonds by which a one-dimensional chain struc- ture is formed.     

Synthesis of cross linked platinum metal containing polyyne polymers

Reaction of Pt(PⁿBu₃)₂Cl₂ (1) or Pt(AsⁿBu₃₂Cl₂ (2) with stoichiometric amounts of 1,3,5-triethynylbenzene, [1,3,5-(H? C?C? )₃C₆H₃] (3)yields monomeric, [1,3,5-Cl(PⁿBu₃)₂(Pt? C? C? )₃C₆H₃] (4), [1,3,5-(C1)(AsⁿBu₃)₂Pt? C? C? ₃C₆H₃] (5) or polymeric, {1,3,5-[(PⁿBu₃)₂Pt? C?C? ]₃C₆H₃? )ⁿ (6), {1,3,5-[(AsⁿBu₃)₂Pt? C? C? ]₃C₆H₃? }ⁿ (7) complexes. Treatment of (1) with (3) and 2,5-diethynyl-p-xylene,H? C? C? C₆H₂(CH₃)₂? C? C? H (8) in varying molar ratios yields a series of high molecular weight cross linked platinum metal containing polyyne copolymers.     

Resolution and Crystal Structure of 9α-(3-Azabicyclo[3,3,1]nonanyl)- 2′-cyclopentyl-2′-hydroxyl-2′-thienylacetate

1 INTRODUCTION The design, development and marketing of new chiral drugs are now a major theme in the drug chirality research and industry[1]. In 1996, the FDA announced it would consider further incentives for developing single isomer drugs because of their bet- ter pharmacokinetics prosperity, safety, and tolera- bility. Our recent drug candidate, 9α-(3-azabicyclo- [3,3,1]nonanyl)-2?-cyclopentyl-2?-hydroxyl-2?-thien- ylacetate I, is a potential selective M1 antagonist. It is composed…     

Mechanisms of conformational chirality inversion in bicyclo[4.2.1]nonan-9-one and bicyclo[4.2.2]decane as studied in two-parametric torsional energy surfaces

With the purpose of deciphering conformational inversion processes of typical mobile bicyclic molecules, torsional energy surfaces near the enantiomers of bicyclo[4.2.1]nonan-9-one ( 1 ) and bicyclo-[4.2.2]decane ( 2 ) were prepared using molecular mechanics with an improved two-bond drive technique. Inversion of 1 takes place most favorably via a C_s transition state with the tetramethylene chain over the ethano bridge [ 1B , ΔH^± 6.1 (calculated) vs. 6.8 (observed) kcal/mol]. An alternative pathway involving a C_s local energy minimum ( 1C ), in which the tetramethylene chain is bent over the carbonyl, has a barrier 2.4 kcal higher than 1B . The global energy minimum conformation of 2 has boat–chair cyclooctane and twist–boat cyclohexane rings (BCTB ), and enantiomerizes into its mirror image (BCTB ') via three intermediates: TCTB , CB , and TCTB '. The highest point in the proposed pathway, a saddlepoint CB , is calculated to lie 8.0 kcal/mol above BCTB (observed ΔH^± 7.8 kcal/mol). The advantage of the two-parametric over the one-parametric torsional energy surface is discussed.     

(1R,2s,3S,6R,9S)‐5,5,10,10‐Tetrachloro‐2‐methyltricyclo[7.2.0.03,6]undec‐7‐ene‐4,11‐dione

The title compound, C₁₂H₁₀Cl₄O₂, has a pseudoasymmetric centre at the methyl‐substituted carbon and, in the solid state, a boat‐like conformation.     

The different modes of chiral [1,2,3]triazolo[5,1‐b][1,3,4]thiadiazines: crystal packing,conformation investigation and cellular activity

The crystal structures of four new chiral [1,2,3]triazolo[5,1‐b][1,3,4]thiadiazines are described, namely, ethyl 5′‐benzoyl‐5′H,7′H‐spiro[cyclohexane‐1,6′‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine]‐3′‐carboxylate, C₁₉H₂₂N₄O₃S, ethyl 5′‐(4‐methoxybenzoyl)‐5′H,7′H‐spiro[cyclohexane‐1,6′‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine]‐3′‐carboxylate, C₂₀H₂₄N₄O₄S, ethyl 6,6‐dimethyl‐5‐(4‐methylbenzoyl)‐6,7‐dihydro‐5H‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine‐3‐carboxylate, C₁₇H₂₀N₄O₃S, and ethyl 5‐benzoyl‐6‐(4‐methoxyphenyl)‐6,7‐dihydro‐5H‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine‐3‐carboxylate, C₂₁H₂₀N₄O₄S. The crystallographic data and cell activities of these four compounds and of the structures of three previously reported similar compounds, namely, ethyl 5′‐(4‐methylbenzoyl)‐5′H,7′H‐spiro[cyclopentane‐1,6′‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine]‐3′‐carboxylate, C₁₉H₂₂N₄O₃S, ethyl 5′‐(4‐methoxybenzoyl)‐5′H,7′H‐spiro[cyclopentane‐1,6′‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine]‐3′‐carboxylate, C₁₉H₂₂N₄O₄S, and ethyl 6‐methyl‐5‐(4‐methylbenzoyl)‐6‐phenyl‐6,7‐dihydro‐5H‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine‐3‐carboxylate, C₂₂H₂₂N₄O₃S, are contrasted and compared. For both crystallization and an MTT assay, racemic mixtures of the corresponding [1,2,3]triazolo[5,1‐b][1,3,4]thiadiazines were used. The main manner of molecular packing in these compounds is the organization of either enantiomeric pairs or dimers. In both cases, the formation of two three‐centre hydrogen bonds can be detected resulting from intramolecular N—H…O and intermolecular N—H…O or N—H…N interactions. Molecules of different enantiomeric forms can also form chains through N—H…O hydrogen bonds or form layers between which only weak hydrophobic contacts exist. Unlike other [1,2,3]triazolo[5,1‐b][1,3,4]thiadiazines, ethyl 5′‐benzoyl‐5′H,7′H‐spiro[cyclohexane‐1,6′‐[1,2,3]triazolo[5,1‐b][1,3,4]thiadiazine]‐3′‐carboxylate contains molecules of only the (R)‐enantiomer; moreover, the N—H group does not participate in any significant intermolecular interactions. Molecular mechanics methods (force field OPLS3e) and the DFT B3LYP/6‐31G+(d,p) method show that the compound forming enantiomeric pairs via weak N—H…N hydrogen bonds is subject to greater distortion of the geometry under the influence of the intermolecular interactions in the crystal. For intramolecular N—H…O and S…O interactions, an analysis of the noncovalent interactions (NCIs) was carried out. The cellular activities of the compounds were tested by evaluating their antiproliferative effect against two normal human cell lines and two cancer cell lines in terms of half‐maximum inhibitory concentration (IC₅₀). Some derivatives have been found to be very effective in inhibiting the growth of Hela cells at nanomolar and submicromolar concentrations with minimal cytotoxicity in relation to normal cells.     

8‐Chloro‐6‐phenyl‐4H‐[1,2,4]­triazolo­[4,3‐a][1,5]­benzodiazepin‐5(6H)‐one

The title compound, C₁₆H₁₁ClN₄O, is an anticonvulsant agent. In the crystal, a particularly short C—H?N intermolecular hydrogen bond is noted [H?N 2.22 (2) Å]. The diazepine ring has a boat conformation.     

1,4,4‐Tri­methyl‐9‐phenyl‐8‐oxa‐9‐aza­bi­cyclo­[3.2.2]­non‐6‐en‐2‐one

The structure of the adduct of eucarvone with nitro­so­benzene, C₁₆H₁₉NO₂, is reported. The [3.2.2] bicyclic system corresponds to two seven‐membered rings in boat and distorted chair conformations and a six‐membered ring that adopts a distorted boat conformation. No conjugation is observed between the phenyl group and the N—O system. The packing is directed mainly by a C?O hydrogen bond, C—H?O‐(1 ? x, ?y, z) and by intermolecular C—H?π interactions.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN, [Ph₄P]₂[Se₂Cl₆], and [Ph₄P]₂[Se(Se₅)₂] By symproportionation of elemental selenium and SeCl₄ in polar protic solvents the novel chloroselenates(+II), [SeCl₄]^2? and [Se₂Cl₆]^2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl₄]^2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph₄P]₂[Se₂Cl₆] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se₂Cl₆]^2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se₅)₂]^2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph₄P]₂[Se(Se₅)₂] (space group P2₁/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se₅)₂]^2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se₅]_2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.     

Nitrogen-15 studies of the mechanisms of acetolyses of hexamethylenetetramine and 3,7-diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DAPT)

[¹⁵N₄]-Hexamethylenetetramine (Hexamine), and [¹⁵N₄]-3,7-diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane(DAPT) have been prepared starting from ¹⁵NH₃. Synthetic acetolysis reactions were performed using mixtures of pure [¹⁵N₄]- and [¹⁴N₄]-compounds and the destination of the nitrogen isotopes in the products was determined mass spectrometrically. The results show that relatively little isotopic mixing occurs in the acetolysis of hexamine to DAPT though the formation of some products with isotopic composition [¹⁴N₃¹⁵N₁] and [¹⁴N₁¹⁵N₃] indicates limited ring cleavage. However the more severe conditions used in the formation of 1,3,5-triacetyl-1,3,5-triazacyclohexane (TRAT) give rise to considerable isotopic scrambling. The acetolysis of DAPT to give 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane occurs by selective cleavage of the methylene bridge.     

Bildung siliciumorganischer Verbindungen. LIX. Die Kristall- und MolekülStruktur des Dodecamethyl-heptasila-[4,4,4]-propellans Si7C19H48

Formation of Organosilicon Compounds. LIX. Crystal and Molecular Structure of Dodecamethyl-heptasila-[4,4,4]-propellan Si₇C₁₉H₄₈ 1,1,3,3,7,7,9,9,11,11,13,13-Dodecamethyl-1,3,5,7,9,11,13-heptasila-[4,4,4]-propellan Si₇C₁₉H₄₈ crystallizes in the monoclinic space group P2₁/c with a = 11.499, b = 11.411, c = 22.171 Å, β = 96.95° and Z = 4 formula units. The three independent six-membered rings of the molecule have the same skew-boat-conformation. Along the central Si? C? bond the mean value of the torsion angle within the six-membered rings is 19°. The mean value for the bond length is Si-C = 1.893 Å, but the bond length diminishes within the polycyclic system from the axial C-atom to the outer members of the rings (1.916; 1.880; 1.864 Å). The interatomic distances between CH₃- groups and from CH₃- groups to CH₂- groups shows the twisted conformation to be a result of the contacts between these groups.     

6,7‐Dihydrodibenzo[e,g]azulen‐8(5H)‐one and 12,13‐dihydrobenzo[e]­napth­[2,1‐g]­azulen‐14(11H)‐one

In the structures of the title compounds, 6,7‐di­hydro­dibenzo[e,g]­azulen‐8(5H)‐one, C₁₈H₁₄O, (I), and 12,13‐di­hydro­benzo[e]­napth­[2,1‐g]­azulen‐14(11H)‐one, C₂₂H₁₆O, (II), the azulene group is in a boat‐envelope conformation. The structures are stabilized by weak C—H?O interactions.     

Synthesis of unnatural amino acids containing the 3,7-diazabicyclo-[3,3,1]nonane unit

Unnatural amino acids containing the 3,7-diazabicyclo[3,3,1]nonane unit were synthesized in one step by the reaction of diethyl 3-oxoglutarate, bis(methoxycarbonylmethyl) sulfone, with formaldehyde and primary amino acids under conditions of the Mannich reaction. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1236–1244, August, 2008.