Thermisches Verhalten von 1,2-Dipropenylbenzolen

1-cis, 2-cis-Dipropenylbenzene (cis, cis- 1 ) isomerises thermally at 215–235° with 1st order kinetics to give trans, cis- 1 and vice versa. At equilibrium 89% trans, cis- and 11% cis, cis- 1 are present. It is shown by thermal rearrangement of cis, cis-2′, 2″-d₂- 1 that the isomerisation is attributable to aromatic [1, 7a]-sigmatropic H-shifts. trans, trans- 1 rearranges thermally at 225–245° to yield 2, 3-dimethyl-1, 2-dihydronaphthalene ( 2 ). The formation of 2 can be visualized by disrotatory ring closure followed by an aromatic [1, 5s]-sigmatropic H-shift. 2 is also formed when, cis, cis- or trans, cis- 1 are heated for 153 h at 225°. Besides 2 a small amount (3%) of 1-ethyl-1, 2-dihydronaphthalene ( 5 ) is formed. The rearrangement of trans, trans- 1 and trans, trans-2′, 2″-d₂- 1 shows a secondary isotope effect k_H/k_D = 0,90.     

A relativistic CI study on OIII: wavefunctions,excitation energies and transition probabilities

The relativistic CI method is used to determine N-electron wavefunctions for the 1s ² 2s ² 2p ² (³ P ₀,³ P ₂,¹ D ₂), 1s ² 2p ^{4 3} P ₂ even levels, and the 1s ²2s2p ³ (³ D ₁,³ P ₁,³ S ₁,¹ P ₁), 1s ²2s ²2p3s (³ P ₁ and¹ P ₁), 1s ²2s ²2p3d (³ D ₁,³ P ₁,¹ P ₁)J=1 OIII levels. Excitation energies and emission probabilities between these levels are reported in the electric dipole approximation, both for the Coulomb and the Babushkin gauges.ns, p,np,nd- andnd (n17) numerical basis functions have been used for the construction of CSF's entering the CI expansion for the ASF's of these levels. Radiative matrix elements of the type calculated here within the framework of the relativistic CI method, may be used in laser assisted spectroscopic studies of atoms and ions.     

Helical silica nanotubes: Nanofabrication architecture,transfer of helix and chirality to silica nanotubes

A series of neutral gelators and cationic amphiphiles derived from 1,2 diphenylethylenediamine (I) and 1,2-cyclohexanediamine (II) was synthesised. Helical silica nanotubes were prepared utilising these organic gelators through sol-gel polycondensation of tetraethoxy silane, (TEOS-silica source). Right- and left-handed helical nanotubes respectively were obtained from a 1: 1 mass mixture of optically active, (1S,2S)-III-(1S,2S)-V neutral gelator and (1S,2S)-IV-(1S,2S)-VI cationic amphiphile and a 1: 1 mass mixture of optically active, (1R,2R)-III-(1R,2R)-V neutral gelator and (1R,2R)-IV-(1R,2R)-VI cationic amphiphile, indicating that the handedness of the helical nanotubes varied with the change in the neutral gelator precursors used. The nanotubes were characterised by SEM images.     

Berechnung der Röntgen- und Auger-Linien des Methans mit Hilfe des Pseudo-Neon-Modells

Zusammenfassung Mit Hilfe des Pseudoneonmodells wurden die Energien der aus den folgenden Konfigurationen hervorgehenden Terme bzw. Mittelwerte dieser Energien für das Methanmolekül bestimmt: [(1s)² (2s)² (2p)⁶], [(1s)¹ (2s)² (2p)⁶], [(1s)¹ (2s)² (2p)⁶ (3p)¹], [(1s)¹ (2s)² (2p)⁶ (4p)¹], [(1s)¹ (2s)² (2p)⁶ (3d)¹], [(1s)² (2s)¹ (2p)⁵], [(1s)² (2s)² (2p)⁴] und [(1s)² (2s)⁰ (2p)⁶].Die Energien wurden mit Hilfe der Slater-Condonschen Regeln analytisch berechnet und dann mit einer elektronischen Rechenmaschine (Zuse 23) minimisiert.Aus den erhaltenen Energiewerten wurde die Lage der Röntgen- und Auger-Linien des Methans berechnet. Die von Mehlhorn [8] gemessenen Auger-Elektronenenergien konnten zugeordnet werden.Die Rechenergebnisse stimmen mit den von Chun aus Röntgenabsorptionsmessungen ermittelten experimentellen Werten befriedigend überein.

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The pseudo neon model is used to calculate the energies of the levels deriving from the following configurations (or their mean values) of the methane molecule: [(1s)² (2s)² (2p)⁶], [(1s)¹(2s)²(2p)⁶], [(1s)¹(2s)²(2p)⁶(3p)¹], [(1s)¹ (2s)² (2p)⁶ (4p)¹], [(1s)¹ (2s)² (2p)⁶ (3d)¹], [(1s)² (2s)¹ (2p)⁵], [(1s)² (2s)² (2p)⁴] and [(1s)² (2s)² (2p)⁶].The energy expressions are given by the Slater-Condon rules; the minimization is done with a digital computer (Zuse 23). Prom the energy values obtained the X-ray and Auger lines of methane are calculated. An interpretation of the experimental Auger electron energies of Mehlhorn [8] is made.Calculated and measured (by Chun) values are in satisfactory agreement with each other.

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Résumé A l'aide du modèle du pseudo-atome de néon, les énergies des niveaux dérivant des configurations suivantes (ou leurs moyens) ont été calculées: [(1s)² (2s)² (2p)⁶], [(1s)¹ (2s)² (2p)⁶], [(1s)¹(2s)²(2p)⁶(3p)¹], [(1s)¹(2s)²(2p)⁶(4p)¹], [(1s)¹ (2s)² (2p)⁶ (3d)¹], [(1s)² (2s)¹ (2p)⁵], [(1s)² (2s)² (2p)⁴] et [(1s)² (2s)⁰ (2p)⁶].Les énergies sont données par les règles de Slater et Condon et minimisées à l'aide d'une machine à calculer électronique (Zuse 23).On en dérive les spectres X et d'Auger du méthane. Nous pouvions interpréter les énergies des électrons Auger mesurées par Mehlhorn [8]. Les calculs s'accordent assez bien aux valeurs expérimentales de Chun.

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Auszug aus der Dissertation von T. K. Ha, Frankfurt am Main, 1963.     

Monomer-isomerization polymerization. XVIII. Monomer-isomerization copolymerizations of 4-phenyl-2-butene with 4-methyl-2-pentene and 3-heptene with Ziegler-Natta catalyst

4-Phenyl-2-butene (4Ph2B) undergoes monomer-isomerization copolymerization with 4-methyl-2-pentene (4M2P) and 2-and 3-heptene (2H and 3H) with TiCl₃–(C₂H₅)₃Al catalyst at 80°C to produce copolymer consisting exclusively of 1-olefin units. For comparison the copolymerization of 4-phenyl-1-butene (4Ph1B) with 4-methyl-1-pentene (4M1P) and 1-heptene (1H) was carried out under similar conditions. The composition of the copolymers obtained from these copolymerizations was determined from the ratios of optical densities D₁₃₈₀ and D₁₆₀₀ of infrared (IR) spectra of their thin films. The apparent monomer reactivity ratios for the monomer-isomerization copolymerization of 4Ph2B with 4M2P, 2H, and 3H in which the concentration of olefin monomer in the feed was used as internal olefin and those for the copolymerization of 4Ph1B with 4M1P and 1H were determined as follows: 4Ph2B(M₁)-4M2P(M₂); r₁ = 0.90, r₂ = 0.20, 4Ph1B(M₁)-4M1P (M₂); r₁ = 0.40, r₂ = 0.70, 4Ph2B(M₁)-2H(M₂); r₁, = 0.45, r₂ = 1.85, 4Ph2B(M₁)-3H(M₂); r₁ = 0.50, r₂ = 1.20, 4Ph1B(M₁)-1H(M₂); r₁ = 0.55, r₂ = 0.75. The difference in monomer reactivity ratios seemed to originate from the rate of isomerization from 2- or 3-olefins to 1-oletins in these monomer-isomerization copolymerizations.     

Different coordination modes of trans‐2‐{[(2‐methoxyphenyl)imino]methyl}phenoxide in rare‐earth complexes: influence of the metal cation radius and the number of ligands on steric congestion and ligand coordination modes

A simple and effective synthetic route to homo‐ and heteroleptic rare‐earth (Ln = Y, La and Nd) complexes with a tridentate Schiff base anion has been demonstrated using exchange reactions of rare‐earth chlorides with in‐situ‐generated sodium (E)‐2‐{[(2‐methoxyphenyl)imino]methyl}phenoxide in different molar ratios in absolute methanol. Five crystal structures have been determined and studied, namely tris(2‐{[(2‐methoxyphenyl)imino]methyl}phenolato‐κ³O¹,N,O²)lanthanum, [La(C₁₄H₁₂NO₂)₃], ( 1 ), tris(2‐{[(2‐methoxyphenyl)imino]methyl}phenolato‐κ³O¹,N,O²)neodymium tetrahydrofuran disolvate, [La(C₁₄H₁₂NO₂)₃]·2C₄H₈O, ( 2 )·2THF, tris(2‐{[(2‐methoxyphenyl)imino]methyl}phenolato)‐κ³O¹,N,O²;κ³O¹,N,O²;κ²N,O¹‐yttrium, [Y(C₁₄H₁₂NO₂)₃], ( 3 ), dichlorido‐1κCl,2κCl‐μ‐methanolato‐1:2κ²O:O‐methanol‐2κO‐(μ‐2‐{[(2‐methoxyphenyl)imino]methyl}phenolato‐1κ³O¹,N,O²:2κO¹)bis(2‐{[(2‐methoxyphenyl)imino]methyl}phenolato)‐1κ³O¹,N,O²;2κ³O¹,N,O²‐diyttrium–tetrahydrofuran–methanol (1/1/1), [Y₂(C₁₄H₁₂NO₂)₃(CH₃O)Cl₂(CH₄O)]·CH₄O·C₄H₈O, ( 4 )·MeOH·THF, and bis(μ‐2‐{[(2‐methoxyphenyl)imino]methyl}phenolato‐1κ³O¹,N,O²:2κO¹)bis(2‐{[(2‐methoxyphenyl)imino]methyl}phenolato‐2κ³O¹,N,O²)sodiumyttrium chloroform disolvate, [NaY(C₁₄H₁₂NO₂)₄]·2CHCl₃, ( 5 )·2CHCl₃. Structural peculiarities of homoleptic tris(iminophenoxide)s ( 1 )–( 3 ), binuclear tris(iminophenoxide) ( 4 ) and homoleptic ate tetrakis(iminophenoxide) ( 5 ) are discussed. The nonflat Schiff base ligand displays μ₂‐κ³O¹,N,O²:κO¹ bridging, and κ³O¹,N,O² and κ²N,O¹ terminal coordination modes, depending on steric congestion, which in turn depends on the ionic radii of the rare‐earth metals and the number of coordinated ligands. It has been demonstrated that interligand dihedral angles of the phenoxide ligand are convenient for comparing steric hindrance in complexes. ( 4 )·MeOH has a flat Y₂O₂ rhomboid core and exhibits both inter‐ and intramolecular MeO—H…Cl hydrogen bonding. Catalytic systems based on complexes ( 1 )–( 3 ) and ( 5 ) have demonstrated medium catalytic performance in acrylonitrile polymerization, providing polyacrylonitrile samples with narrow polydispersity.     

Stereoselective and Enantioselective Syntheses of the Four Stereoisomers of Muscol from (3RS)‐Muscone

Two trans stereoisomers of 3‐methylcyclopentadecanol (=muscol), (1R,3R)‐ 2 and (1S,3S)‐ 2 , were efficiently synthesized from (3RS)‐3‐methylcyclopentadecanone (=muscone; (3RS)‐ 1 ) by a highly stereoselective reduction (Scheme). L‐Selectride^® (=lithium tri(sec‐butyl)borohydride) was used, followed by the enantiomer resolution by lipase QLG (Alcaligenes sp.). The cis stereoisomers of muscol, (1S,3R)‐ 2 and (1R,3S)‐ 2 , were obtained by the Mitsunobu inversion of (1R,3R)‐ 2 and (1S,3S)‐ 2 , respectively (Scheme). The absolute configuration of (1R,3R)‐ 2 was determined by X‐ray crystal‐structure analysis of its 3‐nitrophthalic acid monoester, 2‐[(1R,3R)‐3‐methylcyclopentadecyl hydrogen benzene‐1,2‐dicarboxylate ((1R,3R)‐ 3b ), and by oxidation of (1R,3R)‐ 2 to (3R)‐muscone.     

Azimine IV. Kinetik und Mechanismus der thermischen Stereoisomerisierung von 2,3-Diaryl-1-phthalimido-aziminen

Azimines IV. Kinetics and Mechanism of the Thermal Stereoisomerization of 2,3-Diaryl-1-phthalimido-azimines¹) Mixtures of (1E, 2Z)- and (1Z, 2E)-2-phenyl-1-phthalimido-3-p-tolyl-azimine ( 3a and 3b , resp.) and (1E, 2Z)- and (1Z, 2E)-3-phenyl-1-phthalimido-2-p-tolylazimine ( 4a and 4b , resp.) were obtained by the addition of oxidatively generated phthalimido-nitrene (6) to (E)- and (Z)-4-methyl-azobenzene ( 7a and 7b , resp.). Whereas complete separation of the 4 isomers 3a, 3b, 4a and 4b was not possible, partial separation by chromatography and crystallization led to 5 differently composed mixtures of azimine isomers. The spectroscopic properties of these mixtures (UV., ¹H-NMR.) were used to determine the ratios of isomers in the mixtures, and served as a tool for the assignment of constitution and configuration to those isomers which were dominant in each of these mixtures, respectively. Investigation of the isomerization of the azimines 3a, 3b, 4a and 4b within the 5 mixtures at various concentrations by ¹H-NMR.-spectroscopy at room temperature revealed that only stereoisomers are interconverted ( 3a ? 3b; 4a ? 4b) and that the (1E, 2Z) ? (1Z, 2E) stereoisomerization is a unimolecular reaction. These observations exclude an isomerization mechanism via an intermediate 1-phthalimido-triaziridine (2) or via dimerization of 1-phthalimido-azimines (1) , respectively. The 3-p-tolyl substituted stereoisomers 3a and 3b isomerized slightly slower than the 3-phenyl substituted ones 4a and 4b , an effect which is consistent with the assumption that the rate determining step of the interconversion of (1E, 2Z)- and (1Z, 2E)-1-phthalimido-azimines (1a ? 1b) is the stereoisomerization of the stereogenic center at N(2), N(3), either by inversion of N(3) or by rotation around the N(2), N(3) bond. The total isomerization process is assumed to occur via the thermodynamically less stable (1Z, 2Z)- and (1E, 2E)-isomers 1c and 1d , respectively, as intermediates in undetectably low concentrations which stay in rapidly established equilibria with the observed, thermodynamically more stable (1E, 2Z)- and (1Z, 2E)-isomers 1a and 1b , respectively. At higher temperatures, the azimines 3 and 4 are transformed into N-phenyl-N,N′-phthaloyl-N′-p-tolyl-hydrazine (8) with loss of nitrogen.     

1‐Aminoindan‐2‐ol,a Suitable Ligand for the Synthesis of Chiral,Intramolecularly Stabilized Compounds of Aluminum,Gallium, and Indium

The reactions of enantiomerically pure (1R, 2S)‐(+)‐cis‐1‐aminoindan‐2‐ol, (1S, 2R)‐(‐)‐cis‐1‐aminoindan‐2‐ol, and racemic trans‐1‐aminoindan‐2‐ol with trimethylaluminum, ‐gallium, and ‐indium produce the intramolecularly stabilized, enantiomerically pure dimethylmetal‐1‐amino‐2‐indanolates (1R, 2S)‐(+)‐cis‐Me₂AlO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 1 ), (1S, 2R)‐(‐)‐cis‐Me₂AlO‐2C*HC₇H₆‐1‐C*HNH₂ ( 2 ), (1R, 2S)‐(+)‐cis‐Me₂GaO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 3 ), (1R, 2S)‐(+)‐cis‐Me₂InO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 4 ), (1S, 2R)‐(‐)‐cis‐Me₂InO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 5 ), and racemic (+/‐)‐trans‐Me₂InO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 6 ). The compounds were characterized by ¹H NMR, ¹³C NMR, ²⁷Al NMR and mass spectra as well as 1 and 3 to 6 by determination of their crystal and molecular structures. The dynamic dissociation/association behavior of the coordinative metal‐nitrogen bond was studied by low temperature ¹H NMR spectroscopy.     

Synthesis and structures of two molybdenum(VI) complexes derived from similar benzohydrazone ligands with catalytic properties

Two new structurally similar molybdenum(VI) complexes, [MoO₂L¹(CH₃OH)] (1) and [MoO₂L²(CH₃OH)] (2), where L¹ is the dianionic form of N′-(2-hydroxy-5-nitrobenzylidene)-2-methylbenzohydrazide and L² is the dianionic form of N′-(2-hydroxy-4-methoxybenzylidene)-2-methylbenzohydrazide, were prepared and structurally characterized by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P2₁/c, with unit cell dimensions a?=?7.941(1), b?=?14.337(2), c?=?15.141(2)?Å, β?=?92.782(2)°, V?=?1721.8(4)?ų, Z?=?4, R₁?=?0.0286, wR₂?=?0.0650, GOOF?=?1.028. 2 crystallizes in the triclinic space group P-1, with unit cell dimensions a?=?8.003(1), b?=?10.608(1), c?=?10.880(1)?Å, α?=?95.745(2)°, β?=?97.627(2)°, γ?=?105.762(2)°, V?=?872.0(2)?ų, Z?=?2, R₁?=?0.0226, wR₂?=?0.0595, GOOF?=?1.116. X-ray analysis indicates that Mo in the complexes are coordinated by the phenolate oxygen, imino nitrogen, and enolate oxygen of the benzohydrazone, methanol, and two oxo groups, generating octahedral coordination. The oxidation of olefins with the complexes as catalysts was evaluated, indicating that the complexes showed excellent catalytic efficiency in oxidation of most aliphatic and aromatic substrates under mild conditions using tert-butyl hydrogen peroxide as oxidant.     

1,3‐Oxathiolanes from the Reaction of Aromatic and Enolized Thioketones with Monosubstituted Oxiranes

The reactions of 4,4′‐dimethoxythiobenzophenone ( 1 ) with (S)‐2‐methyloxirane ((S)‐ 2 ) and (R)‐2‐phenyloxirane ((R)‐ 6 ) in the presence of a Lewis acid such as BF₃?Et₂O, ZnCl₂, or SiO₂ in dry CH₂Cl₂ led to the corresponding 1 : 1 adducts, i.e., 1,3‐oxathiolanes (S)‐ 3 with Me at C(5), and (S)‐ 7 and (R)‐ 8 with Ph at C(4) and C(5), respectively. A 1 : 2 adduct, 1,3,6‐dioxathiocane (4S,8S)‐ 4 and 1,3‐dioxolane (S)‐ 9 , respectively, were formed as minor products (Schemes 3 and 5, Tables 1 and 2). Treatment of the 1 : 1 adduct (S)‐ 3 with (S)‐ 2 and BF₃?Et₂O gave the 1 : 2 adduct (4S,8S)‐ 4 (Scheme 4). In the case of the enolized thioketone 1,3‐diphenylprop‐1‐ene‐2‐thiol ( 10 ) with (S)‐ 2 and (R)‐ 6 in the presence of SiO₂, the enesulfanyl alcohols (1′Z,2S)‐ 11 and (1′E,2S)‐ 11 , and (1′Z,2S)‐ 13 , (1′E,2S)‐ 13 , (1′Z,1R)‐ 15 , and (1′E,1R)‐ 15 , respectively, as well as a 1,3‐oxathiolane (S)‐ 14 were formed (Schemes 6 and 8). In the presence of HCl, the enesulfanyl alcohols (1′Z,2S)‐ 11 , (1′Z,2S)‐ 13 , (1′E,2S)‐ 13 , (1′Z,1R)‐ 15 , and (1′E,1R)‐ 15 cyclize to give the corresponding 1,3‐oxathiolanes (S)‐ 12 , (S)‐ 14 , and (R)‐ 16 , respectively (Schemes 7, 9, and 10). The structures of (1′E,2S)‐ 11 , (S)‐ 12 , and (S)‐ 14 were confirmed by X‐ray crystallography (Figs. 1–3). These results show that 1,3‐oxathiolanes can be prepared directly via the Lewis acid‐catalyzed reactions of oxiranes with non‐enolizable thioketones, and also in two steps with enolized thioketones. The nucleophilic attack of the thiocarbonyl or enesulfanyl S‐atom at the Lewis acid‐complexed oxirane ring proceeds with high regio‐ and stereoselectivity via an S_n 2‐type mechanism.     

Boron heterocycles derived from 2-guanidinobenzimidazole

The syntheses and structure determinations of a series of boron heterocycles derived from 2-guanidinobenzimidazole 1 are reported. Structures of new compounds, 2-guanidino-1-methyl-benzimidazole 2, diphenyl-(2-guanidinobenzimidazole-N,N′)-borate 3, diphenyl-(2-guanidino-1-methyl-benzimidazole-N,N′)borate 4, hydroxy-phenyl-(2-guanidino-benzimidazole-N,N′)borate 5, hydroxy-phenyl-(2-guanidino-1-methyl-benzimidazole-N,N′)borate 6,methoxy-phenyl-(2-guanidinobenzimidazole-N,N′)borate 7, isopropoxy-phenyl-(2-guanidinobenzimidazole-N,N′)borate 8, acetoxy-phenyl-(2-guanidinobenzimidazole-N,N′)borate 9, methoxy-phenyl-(2-guanidino-1-methyl-benzimidazole-N,N′)borate 10, dihy-droxy-(2-guanidino-1-methyl-benzimidazole-N,N′)borate 16, difluoro-(2-guanidinobenzimidazole-N,N′)borate, 17, dihydroxy-(2-guanidino-1-benzimidazole-N,N′)borate potassium salt 19, diphenyl-(2-guanidinium-10H-benzimidazole-N,N′)borate hydro-chloride 20, methoxy-phenyl-(2-guanidinobenzimidazole-N,N′)borate hydrochloride 21, and N10-borane-(diphenyl-2-guanidinobenzimidazole-N,N′)borate 22, were determined based on ¹H, ¹³C, ¹⁵N, and ¹¹B spectroscopy. The X-ray diffraction structures of 3–7, 19, and 20 were obtained. The formation of N3-borane adducts 11 and 12 derived from compounds 1 and 2, respectively, and the dihydride-(2-guanidinobenzimidazole-N,N′)borate 13 and dihydride-(2-guanidino-1-methyl-benzimidazole-N,N′)borate 14 were observed by ¹¹B NMR. The results show that 2-guanidinobenzimidazole gives stable borate heterocycles with a delocalized π electronic system. A dynamic exchange of N–H protons was observed with preferred protonation at N-12. The new heterocycles are protonated at N-10 by acidic substances to give pyridinium-type heterocycles or can lose a proton to give iminium salts. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:399–409, 1998     

Synthesis of (1′S*,2R*,3R*)- and (1′S*,2R*,3S*)-N-arylsulfonyl-2-(1′-halogenethyl)-3-methylindolines and their selective toxicity against SH-SY5Y cell line

N-tosyl-2- and N-tosyl-4-halogen-substituted derivatives of 2-(1-methylbut-2-en-1-yl)aniline were synthesized and their molecular iodine-mediated cyclization was investigated. The cyclization upon interaction of N-tosyl-6-methyl-2-(1-methylbut-2-en-1-yl)aniline with molecular iodine in methyl tert-butyl ether or acetonitrile was studied, as well as the interaction of this sulfonamide with N-bromosucinimide in dichloromethane. Synthesized (2R*,3R*)- and (2R*,3S*)-N-arylsulfonyl-2-(1-halogenoethyl)-3-methylindoline derivatives showed cytotoxic activity against HEK293 cells, SH-SY5Y, Jurkat, and HepG2 cell lines. The compounds (2R*,3S*)-N-arylsulfonyl-7-bromo-2-(1-halogenoethyl)-3-methylindoline cis- 4a , stereoisomeric (2R*,3R*)-trans- 4h and (2R*,3S*)-N-tosyl-7-chloro-2-(1-halogenoethyl)-3-methylindoline cis- 4h demonstrated selective toxicity against SH-SY5Y cell line (IC₅₀ ≈ 3 ÷ 5 μM), and did not affect HEK293, Jurkat, and HepG2 cells.     

One‐Pot,Asymmetric and Diastereoselective Four‐Component Synthesis of Polyfunctional (Z)‐Alkenyl Methyl Sulfones with Three Stereogenic Centers

The reaction of 1‐(trimethylsilyloxy)cyclopentene ( 9 ) with (±)‐1,3,5‐triisopropyl‐2‐(1‐(RS)‐{[(1E)‐2‐methylpenta‐1,3‐dienyl]oxy}ethyl)benzene ((±)‐ 4a ) in SO₂/CH₂Cl₂ containing (CF₃SO₂)₂NH, followed by treatment with Bu₄NF and MeI gave a 3.0 : 1 mixture of (±)‐(2RS)‐2{(1RS,2Z,4SR)‐2‐methyl‐4‐(methylsulfonyl)‐1‐[(RS)‐1‐(2,4,6‐triisopropylphenyl)ethoxy]pent‐2‐en‐1‐yl}cyclopentanone ((±)‐ 10 ) and (±)‐(2RS)‐2‐{(1RS,2Z)‐2‐methyl‐4‐[(SR)‐methylsulfonyl]‐1‐[(SR)‐1‐(2,4,6‐triisopropylphenyl)ethoxy]pent‐2‐en‐1‐yl}cyclopentanone ((±)‐ 11 ). Similarly, enantiomerically pure dienyl ether (−)‐(1S)‐ 4a reacted with 1‐(trimethylsilyloxy)cyclohexene ( 12 ) to give a 14.1 : 1 mixture of (−)‐(2S)‐2‐{(1S,2Z,4R)‐2‐methyl‐4‐(methylsulfonyl)‐1‐[(S)‐1‐(2,4,6‐triisopropylphenyl)ethoxy]pent‐2‐enyl}cyclohexanone ((−)‐ 13a ) and its diastereoisomer 14a with (1S,2R,4R) or (1R,2S,4S) configuration. Structures of (±)‐ 10 , (±)‐ 11 , and (−)‐ 13a were established by single‐crystal X‐ray crystallography. Poor diastereoselectivities were observed with the (E,E)‐2‐methylpenta‐1,3‐diene‐1‐ylethers (+)‐ 4b and (−)‐ 4c bearing ( 1 S )‐1‐phenylethyl and (1S)‐1‐(pentafluorophenyl)ethyl groups instead of the Greene's auxiliary ((1S)‐(2,4,6‐triisopropylphenyl)ethyl group). The results demonstrate that high α/β‐syn and asymmetric induction (due to the chiral auxiliary) can be obtained in the four‐component syntheses of the β‐alkoxy ketones. The method generates enantiomerically pure polyfunctional methyl sulfones bearing three chiral centers on C‐atoms and one (Z)‐alkene moiety.     

X‐Ray Crystal Structures and Quantum Chemical Calculations of Tetraphenyl‐arsonium Tetraazidoaurate(III) and Azido(triphenylphosphine)Gold(I)

The single crystal X‐ray structure determinations are reported for [Ph₄As][Au(N₃)₄] ( 1 ) and Ph₃PAuN₃ ( 2 ). Compound 1 is an ionic species with a “windmill” shaped anion. It crystallizes in the monoclinic space group C2/c, a = 18.396(2), b = 6.2492(4), c = 23.555(2) Å; β = 107.98(1)°, Z = 4, R1_{(all data)} = 0.0227, wR2 = 0.0374. The lattice parameters of compound 2 , which crystallizes in the orthorhombic space group P2₁2₁2₁, are a = 10.9252(1), b = 11.5642(1), c = 13.0993(1) Å; Z = 4, R1_{(all data)} = 0.0176, wR = 0.0334. The experimentally obtained X‐ray data and vibrational frequencies of both compounds were compared with those calculated at B3LYP/LANL2DZ and B3LYP/SDD level of theory and for 1 also at the MP2/SDD level.     

Cationic copolymerization of cyclic ketene acetals: The effect of substituents on reactivity

Cationic copolymerizations of 4-methyl-2-methylene-1,3-dioxane, 2 (M₁), with 2-methylene-1,3-dioxane, 1 (M₂); of 4,4,6-trimethyl-2-methylene-1,3-dioxane, 3 (M₁), with 2-methylene-1,3-dioxane, 1 (M₂); of 4-methyl-2-methylene-1,3-dioxolane, 5 (M₁), with 2-methylene-1,3-dioxolane, 4 (M₂); and of 4,5-dimethyl-2-methylene-1,3-dioxolane, 6 (M₁), with 2-methylene-1,3-dioxolane, 4 (M₂) were conducted. The reactivity ratios for these four types of copolymerizations were r₁ = 1.73 and r₂ = 0.846; r₁ = 2.26 and r₂ = 0.310; r₁ = 1.28 and r₂ = 0.825; r₁ = 2.23 and r₂ = 0.515, respectively. The relative reactivities of these monomers towards cationic polymerization are: 3 > 2 > 1; and 6 > 5 > 4. With both five- and six-membered ring cyclic ketene acetals, the reactivity increased with increasing methyl substitution on the ring. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 861–871, 1998     

Die Hydrolyse von 6exo-substituierten 2exo- und 2endo-Norbornylestern der p-Toluolsulfonsäure. Norbornanreihe. 3. Mitteilung

The Hydrolysis of 6 exo -Substituted 2 exo - and 2 endo -Norbornyl p -Toluenesulfonates. Norbornane Series. Part 3 Hydrolysis of the 6exo-substituted 2exo- and 2endo-norbornyl p-toluenesulfonates 1b - 1 and 2b - 1 , respectively, in 70% dioxane led to different amounts of the following products: Unrearranged 2exo-norbornanols 3 and norbornenes 5 , accompanied in somes cases by small amounts of the rearranged Rendo-epimers 4 and 6 and by norticyclenes 7 . When the 6exo-substituent was a nucleophilic group as in 1e - 1 and 2e - 1 , various amounts of tricyclic products were also formed by endo-cyclization. These results show that the 2exo- and 2endo-esters 1 and 2 , respectively, react by way of different intermediates. In cases where the 6exo-substituent was an n-electron donor, as in 1m - r and 2m - r , quantitative fragmentation to (3-cyclopentenyl)acetaldehyde (13) occurred.     

Metal Ions Drive Thermodynamics and Photochemistry of the Bis(styryl) Macrocyclic Tweezer

UV/Vis and NMR spectroscopy were used for the structural elucidation and thermodynamic and photochemical studies of the metal‐coordinated crown‐containing macrocyclic tweezer (E,E)‐ 1 . The bis(styryl) tweezer (E,E)‐ 1 formed two types of complexes with magnesium(II): a 1:1 intramolecular asymmetric sandwich complex [(E,E)‐ 1 ]?Mg²⁺ and a 1:2 complex [(E,E)‐ 1 ]?(Mg²⁺)₂. In the former case, there is direct cation intramolecular exchange (0.299 s^?1, ΔG^≠=69.4 kJ mol^?1) between two parts of the bis(styryl) tweezer (E,E)‐ 1 . Addition of barium(II) to the bis(styryl) tweezer (E,E)‐ 1 led to an intramolecular centrosymmetric sandwich 1:1 complex [(E,E)‐ 1 ]?Ba²⁺. Irradiation of [(E,E)‐ 1 ]?Ba²⁺ afforded reversible intramolecular [2π+2π] photocyclization with excellent stereoselectivity and quantitative yield. In contrast, irradiation of [(E,E)‐ 1 ]?(Mg²⁺)₂ resulted in reversible stepwise E,Z‐isomerization.     

Four 1‐naphthyl‐substituted tetrahydro‐1,4‐epoxy‐1‐benzazepines: hydrogen‐bonded structures in one,two and three dimensions

(2S*,4R*)‐2‐exo‐(1‐Naphthyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₀H₁₇NO, (I), crystallizes with Z′ = 2 in the space group P2₁; the two independent molecules have the same absolute configuration, although this configuration is indeterminate. The molecules of each type are linked by a combination of C—H...O and C—H...π(arene) hydrogen bonds to form two independent sheets, each containing only one type of molecule. (2SR,4RS)‐7‐Methyl‐2‐exo‐(1‐naphthyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₁H₁₉NO, (II), crystallizes as a true racemate in the space group P2₁/c, and a combination of C—H...N, C—H...O and C—H...π(arene) hydrogen bonds links the molecules into sheets, each containing equal numbers of the two enantiomorphs. (2S*,4R*)‐2‐exo‐(1‐Naphthyl)‐7‐trifluoromethyl‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₁H₁₆F₃NO₂, (III), crystallizes as a single enantiomorph, as for (I), but now with Z′ = 1 in the space group P2₁2₁2₁; again, the absolute configuration is indeterminate. A single C—H...π(arene) hydrogen bond links the molecules of (III) into simple chains. (2S,4R)‐8‐Chloro‐9‐methyl‐2‐exo‐(1‐naphthyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₁H₁₈ClNO, (IV), crystallizes as a single enantiomorph of well defined configuration, in the space group P2₁2₁2₁, where two independent C—H...π(arene) hydrogen bonds link the molecules into a single three‐dimensional framework structure.     

Evaluation of potential of electric field produced by molecule using symmetrical one-range addition theorems for Coulomb-Yukawa like correlated interaction potentials of integer and noninteger indices

Using symmetrical one-range addition theorems the series expansion formulae in terms of multicenter charge density expansion coefficients for noninteger n Slater type orbitals (STO), parameters of Coulomb-Yukawa like correlated interaction potentials (CIP) of noninteger indices and linear combination coefficients of molecular orbitals are established for the potential of electrostatic field produced by the charges of molecule. The final results are useful for the study of interaction between atomic-molecular systems containing any number of closed and open shells when the Hartree–Fock–Roothaan (HFR) approximation and the explicitly correlated methods based upon the use of STO as basis functions and Coulomb–Yukawa like CIP are employed. As an example of application, the calculations have been performed for the Coulomb interaction potential produced by the ground state of CH ₂ molecule (1a₁² 2a₁² 1b₁² 3a₁¹ 1b₁¹,³B₁ ){(1a_1^2 2a_1^2 1b_1^2 3a_1^1 1b_1^1,^3B_1 )}.