Aminomethylierung von Thiophosphorsäuredialkylester-, Phosphon- bzw. Thiophosphonsäurealkylesteramiden,Phosphon- bzw. Thiophosphonsäurediamiden und Diphenylthiophosphinsäureamid

Aminomethylation of Phosphoro-, Phosphono-, Phosphinoamidoates and -amidothioates Dialkylphosphoroamidates, alkyl-phosphonoamidates and phosphonoamidothioates react with C₂H₅O? CH₂? NR₂ and HCOH/HNR₂, respectively, as like as a N-aminomethylation forming the corresponding derivatives of the general formula R₂P(X)? NR′? CH₂? NR″₂? R = alkoxy, alkyl, aryl; R′ = H, alkyl; X = O, S; R″ = alkyl, cycloalkyl —. Under the same conditions phosphonodiamidoates and phosphonodiamidothioates yield RP(X)-[NR′? CH₂? NR″₂]₂ or RP(X)? NHR′? (NR′? CH₂? NR″₂) only. These compounds are not formed by interactions of RP(X)(NR′? CH₂OH)₂ with sec. amines. The aminomethylation of (C₆H₅)₂P(S)NH₂ gives unexceptional [(C₆H₅)₂P(S)]₂N? CH₂? NR′₂. The i.r. and ¹H-n.m.r. data of the prepared compounds, which can't be distilled mostly, are discussed.     

Preparation and properties of triorganostannylmethyl 2,3:5,6-di-O-isopropylidene-α-D-mannofuranosides; pesticidal and fungicidal activities of triphenylstannyl-carbohydrate derivates

The synthesis of trioganostannylmethyl 2,3:5,6-di-O-isopropylidene-α-D-mannofuranoside (compound 3, R*OCH₂SnR₂R′:R?R′?Me or Ph) from D-mannose is reported. The compound 3 (R?R′?Ph) is transmetallated by PhLi to compound 5, R*OCH₂Li, Which can be trapped by HgCl₂ [as (R*OCH₂)₂Hg] and by ketones, R³COMe [as compound 7, R*OCH₂CR³MeOH]. Two stereoisomers of this compound (7a, R³?Ph) were formed in a ratio of 40:60, indicating some asymmetric induction, arising from the chiral R* moiety. Reactions of compound 3, (R?R′?Ph), with I₂, HO₂CCF₃ and Cl₂PtCOD result in Ph–Sn bond cleavage and formation of compound 3 with R?Ph; R′?I, OCOCF₃ and Cl respectively. Reactions of compound 3 (R?R′?Me) with electrophiles can lead to cleavage of either of both types of C–Sn bonds present (e.g. by I₂, Br₂, Cl₂PtCOD or SnCl₄) or to attack at the C₅–C₆ protecting group with release of acetone (e.g. by CF₃CO₂H, SO₂ or CH₃COCl). Pesticidal and fungicidal activities of compound 3(R?R′?Ph) as well as of 1,2:5,6-di-O-isopropylidene-3-O(triphenylstannylmethyl)-α-D-glucofuranose (compound 2, R?Ph) and methyl 4, 6-O-benzylidene-2-deoxy-2-triphenylstannyl-α-D-altropyranoside (compound 1, R?Ph) are reported.     

Rational Modification of the Hierarchy of Intermolecular Interactions in Molecular Crystal Structures by Using Tunable Halogen Bonds

A family of 16 isomolecular salts (3‐XpyH)₂[MX′₄] (3‐XpyH=3‐halopyridinium; M=Co, Zn; X=(F), Cl, Br, (I); X′=Cl, Br, I) each containing rigid organic cations and tetrahedral halometallate anions has been prepared and characterized by X‐ray single crystal and/or powder diffraction. Their crystal structures reflect the competition and cooperation between non‐covalent interactions: N? H???X′? M hydrogen bonds, C? X???X′? M halogen bonds and π–π stacking. The latter are essentially unchanged in strength across the series, but both halogen bonds and hydrogen bonds are modified in strength upon changing the halogens involved. Changing the organic halogen (X) from F to I strengthens the C? X???X′? M halogen bonds, whereas an analogous change of the inorganic halogen (X′) weakens both halogen bonds and N? H???X′? M hydrogen bonds. By so tuning the strength of the putative halogen bonds from repulsive to weak to moderately strong attractive interactions, the hierarchy of the interactions has been modified rationally leading to systematic changes in crystal packing. Three classes of crystal structure are obtained. In type A (C? F???X′? M) halogen bonds are absent. The structure is directed by N? H???X′? M hydrogen bonds and π‐stacking interactions. In type B structures, involving small organic halogens (X) and large inorganic halogens (X′), long (weak) C? X???X′? M interactions are observed with type I halogen–halogen interaction geometries (C? X???X′ ≈ X???X′? M ≈155°), but hydrogen bonds still dominate. Thus, minor but quite significant perturbations from the type A structure arise. In type C, involving larger organic halogens (X) and smaller inorganic halogens (X′), stronger halogen bonds are formed with a type II halogen–halogen interaction geometry (C? X???X′ ≈180°; X???X′? M ≈110°) that is electrostatically attractive. The halogen bonds play a major role alongside hydrogen bonds in directing the type C structures, which as a result are quite different from type A and B.     

The behaviour of beryllium μ4-oxo-μ-carboxylates under electron impact

The electron impact mass spectra of eight polynuclear beryllium complexes Be₄O(RCO₂)₆ (R?H, CH₃, C₂H₅) and Be₄O(RCO₂)₅OR′ (R?CH₃, R′?H, CH₃, C₂H₅, C₃H₇; R?C₂H₅, R′?C₂H₅) are reported. The major fragmentations involve the elimination of (RCO)₂O (RCOOR′) or Be(RCO₂)₂ (Be(RCO₂)OR′) from the ions [M? L]⁺ and of {(R? H)CO}, (R′? H), H₂O and BeO from the lighter ions. The fragmentation patterns are practically independent of the organic groups present and can be rationalized by stereochemical considerations.     

Synthesis and supramolecular networks of mono- and dinuclear manganese chloride complexes with 2-(2,2′ : 6′,2″-terpyridin-4′-yl)phenol

2-(2,2′?:?6′,2″-Terpyridin-4′-yl)phenol has been prepared with an improved one-pot method. The reaction between the ligand and MnCl₂ in ethanol at ambient or hydrothermal conditions afforded dichlorido[2-(2,2′?:?6′,2″-terpyridin-4′-yl)phenol-κ³ N,N′,N″]manganese(II) and dichloridobis[µ-2-(2,2′?:?6′,2″-terpyridin-4′-yl)phenolate-κ³ N,N′,N″-κO]dimanganese(II), respectively. Face-to-face π–π stacking interactions between the pyridine rings play a crucial role in supramolecular networks of both complexes. Both complexes display weaker photoluminescence than the free ligand and the dinuclear complex luminescence was stronger than the mononuclear one.     

A Non Ambiguous Evidence of the Betain Dissociation as a Part of the “Retro-Wittig” Process

Abstract

The ring-opening of oxiranes by triphenylphosphine in phenol as solvent, at 100°C, follows pathways (a) and (b) in the case of R ? phenyle, or R′, R″? alkyle, or pathway (c) in the case of R, R′? alkyle, R″? H.     

Ab initio molecular fragment calculations with pseudopotentials: Model peptide studies

The energetics of rotation about the N? C′(ω); N? C^α(φ), and C^α? C′(?) bonds of the peptide unit have been investigated in the pseudo-FSGO fragment scheme on model compounds formamide and N-methylacetamide. The results indicated that the position of the minimum in ω is in the near vicinity of 0°, i.e., the planar arrangement of the peptide unit. The minimum in φ (C′? N? C^α? H) has been found to be 180° and in ψ(H? C^α? C′? N) to be 60°, in good agreement with PCILO and Gaussian-70 results.     

Trimethylsilylverbindungen der Vb-Elemente. II. Molekül- und KristallStruktur des Tetrakis(trimethylsilyl)-diarsans

Trimethylsilyl Derivatives of Vb-Elements. II. Molecular and Crystal Structure of Tetrakis(trimethylsilyl)diarsine Pale yellow tetrakis(trimethylsilyl)diarsine 1 which is easily obtained from lithium bis(trimethylsilyl)arsenide · 2 tetrahydrofurane (THF) and 1,2-dibromoethane crystallizes in a trigonal, acentric space group. The dimensions of the unit cell determined at ?95 ± 5°C are: a = 974.2(2); c = 2 080.0(4) pm; Z = 3. Considering anomalous dispersion the refinement of structural data in space group P3₁21 converges at an R-value of 0.060, in its enantiomorph P3₂21, however, at 0.031. With a dihedral angle Si2′? As′? As? Si1 of ?125.7° the molecule adopts gauche conformation. Both bis(trimethylsilyl)arsino groups are symmetry-related by the crystallographic operation of the diad. Characteristic bond lengths and angles are: As? As 245.8(1); As? Si 236.5(1) and 236.2(2) pm; Si? As? Si 100.90(5); As? As? Si 93.87(3) and 113.63(4)°. The shortest intermolecular As? As distance is found to be 662 pm.     

Application of 1′,2,3,3′,4,4′-Hexa-O-benzylsucrose in the Preparation of Sucrose Macrocycles via a Click Chemistry Route: Regioselectivity Study

Abstract

1′,2,3,3′,4,4′-Hexa-O-benzyl-sucrose was applied in the preparation of sucrose-based macrocycles via a click chemistry route. This was realized by protection of the 6′?OH with silyl block followed by elongation of the glucose end with the ?CH₂CH₂N₃ unit. Removal of the silyl block and subsequent propargylation of the released C6′?OH afforded the corresponding synthon, cyclization of which under the click condition provided the desired macrocycle with the expected 1,4-pattern of substituents at the triazole ring.     

Alkali Metal/Ammonia Reductions of Ketones Should Be Run in the Presence of Ammonium Ion

Reduction of (+)-[3,3?²H₂]camphor ([3,3?²H₂] 1 ) with lithium, sodium or potassium in ammonia and a co-solvent gave; 1) the enolate of [3,3?²H₂] 1 and the alcoholates of (?)-[2,3,3?²H₃]isoborneol ([2,3,3?²H₃] and (+)-[2,3,3?²H₃]borneol ([2,3,3?²H₃] 3 ); 2) the alcoholates of [3,3?²H₂] 2 and [3,3?²H₂] 3 ; 3) the dialcoholates of the pinacols [3,3,3′,3′?²H₄] 4 and [3,3,3′,3′?²H₄] 5 . It is proposed that these are formed from the ketyls [3,3?²H₂] 1 - M⁺, by: 1) disproportionation; 2) H-atom abstraction from the medium; 3) dimerization. Protonation upon work-up afforded [endo?3²H] 1 , [2,3,3?²H₃] 2 , [2,3,3?²H₃] 3 ,[3,3?²H₂] 2 , [3,3?²H₂] 3 , [3,3,3′,3′?²H₄] 4 and [3,3,3′,3′?²H₄] 5 . Pinacol [3,3,3′,3′?²H₄] 5 was the main and pinacol [3,3,3′,3′?²H₄] 4 a minor product in the reductions with lithium and both were minor products in the reductions with sodium; pinacols were not formed in the reductions with potassium. Parallel reductions of 1 , unlabeled, analogously led to 2 , 3 , 4 and 5 , and the ratios 2/3 differed from the ratios ([2,3,3?²H₃] 2 +[3,3?²H₂] 2 /([2,3,3?²H₃]+[3,3?²H₂] 3 ) under certain conditions. Different values for these ratios were found in the reductions with each metal, all of which corresponded to low overall diastereoselectivities. Reactions 1 and 3 persisted when the reductions were carried out in ammonia/water/co-solvent mixtures and the enolate formed via reaction 1 was protonated and the resulting [endo-3-²H] 1 recycled. Reaction 2 cannot be monitored under these conditions. Reactions 1 and 3, and by inference also reaction 2, were almost completely suppressed when analogous reductions were carried out in the presence of ammonium chloride, [3,3?²H₂] 2 and [3,3?²H₂] 3 being obtained almost exclusively, in a 6: 94 ratio. It is proposed that the mechanism outlined in House [1] was dominant when, and only when, ammonium ion was the proton source; it may have competed when water was the proton source.     

2Rotaxane based on terpyridyl bimetal ruthenium complexes and β-cyclodextrin as organic sensitizer for dye-sensitized solar cells

The conjugated carboxy-functionalized terpyridyl bimetal ruthenium complex [(tdctpy)Ru(dctpy-(ph)₄-dctpy)Ru(tdctpy)][PF₆]₄ and [2]rotaxane by self-assembly of [(tdctpy)Ru(dctpy-(ph)₄-dctpy)Ru(tdctpy)][PF₆]₄ with β-cyclodextrin are reported as sensitizer for dye-sensitized solar cells (DSSCs), where tdctpy?=?4′-p-tolyl-4,4″-dicarboxy-2,2′?:?6,2″-terpyridine, dctpy?=?4,4″-dicarboxy-2,2′?:?6,2″-terpyridine and dctpy-(ph)₄-dctpy represents a bridging ligand where two 4,4″-dicarboxy-2,2′?:?6′,2″-terpyridine units are connected through four phenyl spacers in the 4′-position. The DSSCs fabricated utilizing these materials give typical electric power conversion efficiency of 0.013–0.523% under air mass (AM) 1.5, 100?mW?cm^?2 irradiation at room temperature. The terpyridyl bimetal ruthenium complex [(tdctpy)Ru(dctpy-(ph)₄-dctpy)Ru(tdctpy)][PF₆]₄ with conjugated-bridge chains displayed much higher conversion efficiency compared with the carboxy-functionalized terpyridyl monometal ruthenium complex [tdctpy-Ru-(idctpy)][PF₆]₂, where idctpy?=?4′-p-iodophenyl-4,4″-dicarboxy-2,2′?:?6,2″-terpyridine. [2]Rotaxane displayed the highest electric power conversion efficiency of 0.523% when β-cyclodextrin was introduced into the conjugated terpyridyl bimetal ruthenium complex and formed [2]rotaxane.     

Halochrome Molekeln 8. Mitteilung. Synthese und acidobasisches Verhalten von 3′-substituierten 6,11-Dihydrospiro[[1]benzopyrano[4,3-b]indol-6,9′−9′H-xanthenen]

Halochromic Molecules. Synthesis and Acidobasic Properties of 3′-substituted 6,11-dihydrospiro[[1]benzopyrano[4,3-b]indol-6,9′?9′9′H-xanthenes] We have synthesized a series of 3′-substituted 6,11-ihydrospiro[6H-chromeno[4,3-b]indol–6,9′?9′H-xanthenes] and one of their respective aza analogues. ¹H-MR data as well as the fragmentation in the mass spectra of starting and final products supported the postulated structures. With acid, the spiro compounds form ring-opened intensely coloured xanthylium salts. UV/VIS spectra of these salts are listed and discussed. The ?_pH* curves in buffered MeOH/H₂O solutions and the pK* values are determined. The title compounds could possibly be used in ‘pressure sensitive papers’.     

Conformations of highly hindered aryl ethers: XXIII–PMR evidence for preferred conformations and intramolecular π complex formation in nitrophenyl naphthyl ethers

The PMR spectrum of 2-bromo-4,6-dinitrophenyl 2′-naphthyl ether ( 1 ) is consistent with the preferential adoption of a twist conformation ( 1a ) in which the 6-nitro group and the 1′-hydrogen are located endo to the ether link. This preference is explained by the formation of an intramolecular π complex between the 6-nitro group and the C1′? C2′ bond, which is stronger than that formed with the C2′? C3′ bond, in accord with their bond orders. This study adduces further evidence in favor of: (a) the adoption of twist conformations by these and related ethers, (b) the importance of intramolecular π complex formation as a conformational influence, (c) the formation of complexes in such cases is with specific portions of, and not the complete, π cloud and (d) indicates that similar effects may be discerned in analogous ethers related to the thyroid hormones.     

Lithographic design of photosensitive polyarylates based on reaction development patterning

The factors affecting pattern‐forming properties in reaction development patterning were examined with polyarylates with various bisphenol moieties. The developability of the photosensitive polyarylates was dependent on the properties of the subtituent (R) in the bisphenol moieties. The development time decreased in the following order: R?C(CH₃)₂ > fluorenyl unit ? phenolphthalein unit > C(CF₃)₂ > SO₂. This order agreed with that of the reactivity between the polyarylates and ethanolamine, and these orders can be explained by pK_a of the bisphenol used to prepare the polyarylates. The development with NH₂? R′? OH resulted in successful positive‐tone pattern formation. However, pattern formation with the developers containing NH₂? R′? OCH₃ was unsuccessful. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2694–2706, 2006     

Metallderivate von Molekülverbindungen. VI. Lithium- und (Tetrahydrofuran)lithium-cyantrimethylsilylamid — Synthese und Struktur

Metal Derivatives of Molecular Compounds. VI. Lithium and (Tetrahydrofuran)lithium Cyanotrimethylsilylamide — Syntheses and Structures At different temperatures N,N′-bis(trimethylsilyl)carbodiimide ( 1 ) and lithium methanide react either under addition or substitution. When compound 1 , however, is treated at ?40°C with an equimolar amount of (1,2-dimethoxyethane-O,O′)lithium phosphanide ( 2 ) in 1,2-dimethoxyethane, only exchange of one trimethylsilyl group versus lithium is observed and in addition to phosphane and tris(trimethylsilyl)phosphane a very pure lithium derivative insoluble in n-pentane can be isolated. The vibrational spectra prove the compound to be lithium cyanotrimethylsilylamide ( 3 ). Recrystallization from tetrahydrofuran (+40/+20°C) yields (tetrahydrofuran)lithium cyanotrimethylsilylamide ( 3 ′). As shown by an X-ray structure analysis {C2/c; a = 2 261.1(5); b = 1 106.4(2); c = 1 045.9(2) pm; β = 113.63(1)°; Z = 8 formula units}, compound 3 ′ is polymeric in the solid state. Coordinative Li? N2′ bonds allow a head-to-tail addition of two monomeric units each to give an eight-membered heterocycle with two linear N1? C2≡N2 fragments (N1? C2 126.1; C2≡N2 117.5; N1? Si 171.4; Li? N1 203.2; Li? N2′ 206.1 pm; C2? N1? Li 109.0; N1? Li? N2′ 115.9; N2≡C2? N1 177.2°). Forming planar four-membered Li? N2? Li? N2 rings (Li? N2″″ 198.3 pm; Li′? N2? Li″ 80.3; N2′? Li? N2″″ 99.5°) these heterocycles polymerize to slightly folded tapes.     

Die identifizierung und untersuchung von isomeren O-acylribonucleosiden mit hilfe des circulardichroismus

The CD spectra of benzoyl, p-nitrobenzoyl and anisoyl derivatives of adenosine, uridine, 1-methylriboside and 1-D-ribofuranosylbenzimidazole are registrated. The possibility of identification of 2′-, 3′-O-acylribonucleosides and observation of acyl groups isomerisation kinetics is shown. The kinetics of 2′?3′ migration of a number of 2′(3′)-O-derivatives, the dependence of kinetic constants on the pH are studied. The features of acyl derivated ribonucleosides CD spectra are discussed.     

Conformation and Atropisomeric Properties of Indometacin Derivatives

The stereochemistry around the N‐benzoylated indole moiety of indometacin was studied by restricting the rotation about the N? C7′ and/or C7′? C1′ bond. In the 2′,6′‐disubstituted ones, an atropisomeric property was found and the atropoisomers were separated and isolated as stable forms. Their biological abilities to inhibit cyclooxygenase‐1 (COX‐1) and cyclooxygenase‐2 (COX‐2) were examined. Only the aR‐isomer showed specific inhibition of COX‐1, and COX‐2 was not inhibited by either atropisomer. Conformational analysis in NMR studies and X‐ray crystallography, and CD spectra in combination with calculations were utilized to elucidate the bioactive conformations.     

Sur la Similitude des Déformations du Noyau Cyclohexanonique Induites par les Groupes Tertiobutyle et gem-Diméthyle

X-ray and NMR (250 MHz) data for chlorinated 4,4-dimethylcyclohexanones lead to the following conclusions: carbonyl and chlorine substituent effects on ²J and ³J coupling constants are similar to those observed for 4-tert-butylcyclohexanones. In other respects, the gem dimethyl and the tert-butyl groups induce on the ring similar large ⁴J coupling constants (H-3′? C-3? C-4? C-5? H-5′); the results can be interpreted in terms of local gemoetric deformations and additivity of these deformations. The determination of dihedral angles by Lambert's method and from X-ray data shows the identity of the structures in the solid state and the dissolved state and confirms the great structural similarity between 4-tert-butyl- and 4,4-dimethylcyclohexanone derivatives.     

Complexes of (bpy)2Ru(II) and (Ph2bpy)2Ru(II) with a series of thienophenanthroline ligands: synthesis,characterization, and electronic spectra

A series of complexes (bpy)₂LRu(II) and (Ph₂bpy)₂LRu(II), where bpy is 2,2′-bipyridine, Ph₂bpy is 4,4′-diphenyl-2,2′-bipyridine and L is 1,10-phenanthroline (phen), [1]benzothieno[2,3-c][1,10]phenanthroline (btp), naphtho[1′,2′?:?5,4]thieno[2,3-c][1,10]phenanthroline [ntpl, l=linear], and naphtho[1′,2′?:?4,5]thieno[2,3-c][1,10]phenanthroline (ntph, h=helical) were synthesized and characterized using 2D COSY NMR spectra. The UV spectra were assigned to study their metal to ligand charge transfer (MLCT) excited states. Complexes of (bpy)₂LRu(II) showed identical absorption wavelengths (λ _max) for the MLCT of all four members of the series with the only variation being the intensity (log _ε ) for each. The MLCT of (Ph₂bpy)₂LRu(II) showed the similar behavior only with different wavelengths showing that in this heteroleptic series of complexes the MLCT is exclusively to the bpy ligands with none to thienophenanthroline (btp, ntpl, or ntph).     

Computer deconvolution applied to the parallel band, ν9 + ν10, of hexadeuteroethane

Computer deconvolution of spectra is discussed, and a close comparison made of deconvoluted spectra with those measured at higher resolution. It is shown that spectra at a resolution of ～0.012 cm^?1 can be obtained by the use of a relatively small grating spectrometer.The parallel band, ν₉ + ν₁₀, of C₂D₆ is examined at a resolution of 0.012 cm^?1 but no K-structure is observed, indicating that (A′?B′)?(A″?B″) is less than 1 × 10^?5 cm^?1. Rotational constants are given for the main band and two hot bands.