Synthesis and Properties of Brominated 6,6'-Dimethyl-[2,2'-bi-1H-indene]-3,3'-diethyl-3,3'-dihydroxy-1,1 '-diones

Photochromic 6‐bromomethyl‐6′‐methyl‐[2,2′‐bi‐1H‐indene]‐3,3′‐diethyl‐3,3′‐dihydroxy‐1,1′‐dione ( 2 ), 6,6′‐ bis(bromomethyl)‐[2,2′‐bi‐1H‐indene]‐3,3′‐diethyl‐3,3′‐dihydroxy‐1,1′‐dione ( 3 ) and 6,6′‐bis(dibromomethyl)‐[2,2′‐ bi‐1H‐indene]‐3,3′‐diethyl‐3,3′‐dihydroxy‐1,1′‐dione ( 4 ) have been synthesized from 6,6′‐dimethyl‐[2,2′‐bi‐1H‐ indene]‐3,3′‐diethyl‐3,3′‐dihydroxy‐1,1′‐dione ( 1 ). The single crystal of 4 was obtained and its crystal structure was analyzed. The results indicate that in crystal 4 , molecular arrangement is defective tightness compared with its precursor 1 . Besides, UV‐Vis absorption spectra in CH₂Cl₂ solution, photochromic and photomagnetic properties in solid state of 2 , 3 and 4 were also investigated. The results demonstrate that when the hydrogen atoms in the methyl group on the benzene rings of biindenylidenedione were substituted by bromines, its properties could be affected considerably.     

Reaction of zinc enolates derived from 1-aryl-2,2-dibromoalkan-1-ones with tetramethyl 2,2′-(1,4-phenylenedimethylidene)dimalonate,dimethyl 3,3′-(1,4-phenylene)bis(2-cyanoacrylate), and 2,2′-(1,4-phenylenedimethylidene)-bis(malononitrile)

Zinc enolates derived from 1-aryl-2,2-dibromoalkanones reacted with tetramethyl 2,2′-(1,4-phenylenedimethylidene)dimalonate, dimethyl 3,3′-(1,4-phenylene)bis(2-cyanoacrylate), and 2,2′-(1,4-phenylenedimethylidene)bis(malononitrile) to give, respectively, tetramethyl 3,3′-(1,4-phenylene)bis(2-alkyl-2-aroylcyclopropane-1,1-dicarboxylates), dimethyl 3,3′-(1,4-phenylene)bis(2-alkyl-2-aroyl-1-cyanocyclopropane-1-carboxylates), and 3,3′-(1,4-phenylene)bis(2-alkyl-2-aroylcyclopropane-1,1-dicarbonitriles) as a single stereoisomer.     

Synthesis and Asymmetric Enantioselective Addition of Chiral Polybinaphthyl and Polybinaphthol I.igands

Four chiral polymers P-1, P-2, P-3 and P-4 were synthesized by the polymerization of （S）-2,2＇-dioctoxy-1,1＇- binaphthyl-6,6＇-boronic acid （S-M-3） with （S）-6,6＇-dibromo-1,1＇-binaphthol （S-M-1）, （R）-6,6＇-dibromo-1,1＇- binaphthol （R-M-1）, （S）-3,3＇-diiodo-1,1＇-binaphthol （S-M-2） and （R）-3,3＇-diiodo-1,1＇-binaphthol （R-M-2） under Pd-catalyzed Suzuki reaction, respectively. All four polymers can show good solubility in some common solvents due to the nonplanarity of the polymers in the main chain backbone and flexible alkyl groups in the side chain. The analysis results indicate that specific rotation and circular dichroism （CD） spectral signals of the alternative S-S chiral polymers P-1 and P-3 are larger than those of S-R chiral polymers P-2 and P-4, but their UV-Vis and fluorescence spectra are almost similar. The results of asymmetric enantioselectivity of four polymers for diethylzinc addition to benzaldehyde indicate that catalytically active center is （R） or （S）-1, 1＇-binaphthol moieties.     

Geminal Ionic Liquids: A Combined Approach to Investigate Their Three‐Dimensional Organisation

Different investigations, such as 1D and 2D NMR spectroscopy, resonance light scattering spectroscopy and molecular dynamics simulations, have been jointly used to achieve a deeper understanding of the degree of structural order in two geminal ionic liquids. In particular, 3,3′‐di‐n‐butyl‐1,1′‐(1,3‐phenylenedimethylene)diimidazolium and 3,3′‐di‐n‐butyl‐1,1′‐(1,4‐phenylenedimethylene)diimidazolium bis[bis(trifluoromethanesulfonyl)imide] have been studied. These geminal ionic liquids were chosen because of the presence of both a rigid phenylenedimethylene link between two imidazolium rings, which should give a high degree of order to the solvent system, and the different shapes of the two cations of the isomers, which could induce different properties and packing in the liquid state. Data collected here show that the two geminal ionic liquids are characterised by a different degree of structural order that induces, for example, a different sensitivity of the two solvent systems to temperature changes or to the presence of a co‐solvent such as methanol.     

Organosoluble polyimides and copolyimides based on 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane and aromatic dianhydrides

1,1‐Bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane (BAPPE) was prepared through nucleophilic substitution reaction of 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane and p‐chloronitrobenzene in the presence of K₂CO₃ in N,N‐dimethylformamide, followed by catalytic reduction with hydrazine and Pd/C. Novel organosoluble polyimides and copolyimides were synthesized from BAPPE and six kinds of commercial dianhydrides, including pyromellitic dianhydride (PMDA, I_a ), 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA, I_b ), 3,3′,4,4′‐ biphenyltetracarboxylic dianhydride (BPDA, I_c ), 4,4′‐oxydiphthalic anhydride (ODPA, I_d ), 3,3′,4,4′‐diphenylsulfonetetracarboxylic dianhydride (DSDA, I_e ) and 4,4′‐hexafluoroisopropylidenediphthalic anhydride (6FDA, I_f ). Differing with the conventional polyimide process by thermal cyclodehydration of poly(amic acid), when polyimides were prepared by chemical cyclodehydration with N‐methyl‐2‐pyrrolidone as used solvent, resulted polymers showed good solubility. Additional, I_a,b were mixed respectively with the rest of dianhydrides (I_c–f) and BAPPE at certain molar ratios to prepare copolyimides with arbitrary solubilities. These polyimides and copolyimides were characterized by good mechanical properties together with good thermal stability. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2082–2090, 2000     

Enantioselective Synthesis of 3,3′‐Diaryl‐SPINOLs: Rhodium‐Catalyzed Asymmetric Arylation/BF3‐Promoted Spirocyclization Sequence

The enantioselective synthesis of a series of C₂‐symmetric 3,3′‐diarylated 1,1′‐spirobiindane‐7,7′‐diols (3,3′‐diaryl‐SPINOLs) was developed by sequential Rh‐catalyzed twofold asymmetric conjugate arylation/BF₃‐promoted diastereoselective spirocyclization (>20:1 d.r. and >99 % ee for all examples). Some phosphoramidite ligands were prepared from the 3,3′‐Ph‐SPINOL and applied to several catalytic asymmetric reactions, and the 3,3′‐diarylated ligands showed higher enantioselectivities than the privileged nonsubstituted ligands.     

Simultaneous Determination of Concentration and Enantiomeric Composition of Amino Acids in Aqueous Solution by Using a Tetrabromobinaphthyl Dialdehyde Probe

3,3′-Diformyl-1,1′-bi-2-naphthol or its methoxymethyl-protected derivative is found to undergo a highly selective reaction with excess bromine in CH₂Cl₂ at reflux to give the novel 5,5′,6,6′-tetrabrominated product (S)- or (R)- 2 . The observed electrophilic substitution at the 5,5′-positons of an optically active binaphthyl compound is unprecedented. Unlike unbrominated 3,3′-diformyl-1,1′-bi-2-naphthol, which is not suitable for fluorescent recognition in water, compound (S)- 2 , in combination with Zn²⁺, exhibits a highly enantioselective fluorescent response toward amino acids in aqueous solution (HEPES buffer, pH 7.4). It is further found that the condensation product of (R)- 2 with tryptophan, (R)- 3 , shows dual-responsive emissions toward amino acids; the short wavelength (λ₁=350 nm) emission is sensitive to the concentration of the substrate regardless of the chiral configuration and the long wavelength (λ₂>500 nm) emission is highly enantioselective. Thus, the use of (R)- 3 allows the simultaneous determination of the concentration and enantiomeric composition of an amino acid sample from one fluorescence measurement.     

Enantioselective addition of diethylzinc to aldehydes catalyzed by 3,3′‐bis(2‐oxazolyl)‐1,1′‐bi‐2‐naphthol (BINOL‐Box) ligands derived from 1,1′‐bi‐2‐naphthol

With 3,3′‐bis(2‐oxazolyl)‐1,1′‐bi‐2‐naphthols (BINOL‐Box) synthesized from 1,1′‐bi‐2‐naphthol (BINOL), the enantioselective addition of diethylzinc to aryl aldehydes proceeded smoothly to give secondary aryl alcohols in good yield with good enantioselectivity. Interestingly, the yields and enantioselectivities were affected by the mixing sequence of the reactants. Furthermore, the synthesis of both enantiomers of the addition products has been achieved using the same ligands by choosing achiral additives, Ti(O‐iPr)₄ and 4A molecular sieves. Copyright © 2000 John Wiley & Sons, Ltd.     

Gold(I)/Chiral Brønsted Acid Catalyzed Enantioselective Hydroamination–Hydroarylation of Alkynes: The Effect of a Remote Hydroxyl Group on the Reactivity and Enantioselectivity

The catalytic enantioselective hydroamination–hydroarylation of alkynes under the catalysis of (R₃P)AuMe/(S)‐3,3′‐bis(2,4,6‐triisopropylphenyl)‐1,1′‐binaphthyl‐2,2′‐diyl hydrogenphosphate ((S)‐TRIP) is reported. The alkyne was reacted with a range of pyrrole‐based aromatic amines to give pyrrole‐embedded aza‐heterocyclic scaffolds bearing a quaternary carbon center. The presence of a hydroxyl group in the alkyne tether turned out to be very crucial for obtaining products in high yields and enantioselectivities. The mechanism of enantioinduction was established by carefully performing experimental and computational studies.     

Polymeric Colorants: Statistical Copolymers of Indigo Building Blocks with Defined Structures

Statistical copolymers of indigo ( 1a ) and N‐acetylindigo ( 1b ) building blocks with defined structures were studied. They belong to the class of polymeric colorants. The polymers consist of 5,5′‐connected indigo units with keto structure and N‐acetylindigo units with uncommon tautomeric indoxyl/indolone (=1H‐indol‐3‐ol/3H‐indol‐3‐one) structure (see 2a and 2b in Fig. 1). They formed amorphous salts of elongated monomer lengths as compared to monomeric indigo. The polymers were studied by various spectroscopic and physico‐chemical methods in solid state and in solution. As shown by small‐angle‐neutron scattering (SANS) and transmission‐electron microscopy (TEM), disk‐like polymeric aggregates were present in concentrated solutions (DMSO and aq. NaOH soln.). Their thickness and radii were determined to be ca. 0.4 and ca. 80 nm, respectively. From the disk volumes and by a Guinier analysis, the molecular masses of the aggregates were calculated, which were in good agreement with each other. Defined structural changes of the polymer chains were observed during several‐weeks storage in concentrated DMSO solutions. The original keto structure of the unsubstituted indigo building blocks reverted to the more flexible indoxyl/indolone structure. The new polymers were simultaneously stabilized by intermolecular H‐bonds to give aggregates, preferentially dimers. Both aggregation and tautomerization were reversible upon dissolution. The polymers were synthesized by repeated oxidative coupling of 1,1′‐diacetyl‐3,3′‐dihydroxybis‐indoles 5 (from 1,1′‐diacetyl‐3,3′‐bis(acetyloxy)bis‐indoles 6 ) followed by gradual hydrolysis of the primarily formed poly(N,N′‐diacetylindigos) 7 (Scheme). N,N′‐Diacetylbis‐anthranilic acids 9 were isolated as by‐products.     

One‐dimensional CuII coordination polymers containing C2h‐symmetric 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate linkers

Two new one‐dimensional Cu^II coordination polymers (CPs) containing the C_2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ⁴O,O′:O′′:O′′′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂]·H₂O}_n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ²O³:O^3′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂(H₂O)]·H₂O}_n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the Cu^II ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).     

Synthesis and mass spectrum of 3,3′-thiobispyridine and polarographic reduction of 1,1′-dimethyl-3,3′-thiobispyridinediium diiodide

3,3′-Thiobispyridine is prepared by reaction of pyridine-3-thiol with 3-bromopyridine. The base peak in the mass spectrum of 3,3′-thiobispyridine is due to the molecular ion which fragments by loss of H, HCN and CS as well as by central bond rupture. The 1,1′-dimethyl diquaternary salt of 3,3′-thiobispyridine is reduced polarographically by a one electron transfer not involving hydrogen to an unstable radical cation at a potential (E_o) of −0.72 V in the pH range 7.4–11.2.     

Synthesis and property of soluble poly(1,1′-dialkyl-3,3′-ferrocenylenevinylene)s via titanium-induced dicarbonyl-coupling reaction of 1,1′-dialkylferrocene-3,3′-dicarbaldehydes

1,1′-Dialkylferrocene-3,3′-dicarbaldehydes ( 1a–c ) with long alkyl chains such as ethyl, hexyl, and dodecyl groups were prepared in 13–25% yield via three-step reactions. The titanium-induced dicarbonyl-coupling reaction of 1a–c gave poly(1,1′-dialkyl-3,3′-ferrocenylenevi-nylene)s ( 2a–c ) in quantitative yields, which were the molecular weights of 3000–10,000 and highly soluble in chloroform, benzene, and hexane. The electrical conductivity and the third-order nonlinear optical susceptibility for poly(1,1′-dihexyl-3,3′-ferrocenylenevinylene) ( 2b ) were estimated to be 1 × 10^?2 S/cm on doping with iodine and 1–4 × 10^?12 esu at a wavelength of 1–2.4 μm, respectively. © 1995 John Wiley & Sons, Inc.     

Synthesis and thermal properties of aryl-substituted rod-like polyimides

This article describes the synthesis and thermal characterization of novel aryl-substituted rod-like homopolyimides. Synthetic aspects of monomer syntheses and one-step polymer synthesis in m-cresol are presented. Polyimides with rod-like chain structure are based on monophenylated pyromellitic dianhydride (MPPMDA), diphenylated pyromellitic dianhydride (DPPMDA), and as rod-like diamine units on phenylated para-phenylene diamine and 1,1′-binaphthyl-4,4′-diamine. As partial flexible units, which have the possibility to be converted into an extended chain conformation, commercially available 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 3,4′-oxydianiline (3,4′-ODA) were used. The polyimides were investigated with respect to solution properties and thermal behavior. © 1993 John Wiley & Sons, Inc.     

Asymmetric oxidative coupling polymerization affording polynaphthylene with 1,1′-bi-2-naphthol units

The oxidative coupling polymerizations of racemic-, (R)-, and (S)-2,2′-dimethoxymethoxy-1,1′-binaphthalene-3,3′-diols were carried out with a copper catalyst with various ligands, such as N,N,N′,N′-tetramethylethylenediamine (TMEDA), (S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine, (−)-sparteine, and (S)-(−)-2,2′-isopropylidenebis(4-phenyl-2-oxazoline) [(−)-Phbox], under an O₂ atmosphere. For example, a 10/1 (v/v) MeOH · H₂O-insoluble polymer with a number-average molecular weight of 3.8 × 10³, from a polymerization with CuCl–TMEDA followed by acetylation of the hydroxyl groups, was obtained in a 71% yield. Polymerization with (−)-Phbox proceeded in an S-selective manner to give a polymer with the highest negative specific rotation from the (S)-monomer. The obtained polymer was successfully converted into a polymer with the optically pure 1,1′-bi-2-naphthol unit based on the original monomer structure, which could be used as a polymeric chiral auxiliary and showed catalytic activity for the asymmetric diethylzinc addition reaction to aldehydes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4528–4534, 2004     

Dense Energetic Nitraminofurazanes

3,3′‐Diamino‐4,4′‐bifurazane ( 1 ), 3,3′‐diaminoazo‐4,4′‐furazane ( 2 ), and 3,3′‐diaminoazoxy‐4,4′‐furazane ( 3 ) were nitrated in 100 % HNO₃ to give corresponding 3,3′‐dinitramino‐4,4′‐bifurazane ( 4 ), 3,3′‐dinitramino‐4,4′‐azofurazane ( 5 ) and 3,3′‐dinitramino‐4,4′‐azoxyfurazane ( 6 ), respectively. The neutral compounds show very imposing explosive performance but possess lower thermal stability and higher sensitivity than hexogen (RDX). More than 40 nitrogen‐rich compounds and metal salts were prepared. Most compounds were characterized by low‐temperature X‐ray diffraction, all of them by infrared and Raman spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and by differential scanning calorimetry (DSC). Calculated energetic performances using the EXPLO5 code based on calculated (CBS‐4M) heats of formation and X‐ray densities support the high energetic performances of the nitraminofurazanes as energetic materials. The sensitivities towards impact, friction, and electrostatic discharge were also explored. Additionally the general toxicity of the anions against vibrio fischeri, representative for an aquatic microorganism, was determined.     

(Perhalogenmethylthio)heterocyclen. XXI. Reaktionen halogenierter perhalogenmethylthiopyrrole: Salz- und radikalbildung,dimerisierung

2-Chloro-3,4,5-tris(trifluoromethylthio)pyrrole ( 2a ), 3-Chloro-2,4,5-tris(trifluoromethylthio)pyarrole ( 2b ) and 3,4-dichloro-2,5-bis(trifluromoethylthio)pyrrole ( 2c ) react with silver nitrate/silver acetate in good yield to give the corresponding N-silver salts 3a-c . Compound 2b forms with an aqueous potassium hydroxide solution the N-potassium salt 4 . Compounds 3a and 3b react with iodine to give the dimeers 2,2′-dichloro-3,3,′ 4,4′5,5′-hexakis(trifluoromethylthio)-2,2′-bi-2H-pyrrolyl ( 5a ) and 3,3′-dichloro-2,2′,4,4′,5,5′-hexakis(trifluoromethylthio)-2,2′-bi-2H-pyrrolyl ( 5b ). The dimers dissociate in solution to the corresponding pyrrolayl radicals. The esr and endor spectra of 3-chloro-2,4,5-tris(trifluoromethylthio)pyrrolyl were measured; coupling constants are given. For the newly prepared substances melting-points, ¹⁹F-nmr and ir spectroscopical data are provided.     

The Knoevenagel product of indolin‐2‐one and ferrocene‐1,1′‐dicarbaldehyde

Indolin‐2‐one (oxindole), (I), undergoes a Knoevenagel condensation with ferrocene‐1,1′‐dicarbaldehyde, (II), to afford the title complex 3,3′‐[(E,E)‐ferrocene‐1,1′‐diyldimethylidyne]diindolin‐2‐one dichloromethane disolvate, [Fe(C₂₈H₂₀N₂O₂)]·2CH₂Cl₂, (IV). The structure of (IV) contains two ferrocene complex molecules in the asymmetric unit and displays, as expected, intermolecular hydrogen bonding (N—H...O=C) between the indolin‐2‐one units. Intermolecular π–π stacking interactions are also observed.     

A Diels-Alder Approach to 4,4′-Ihiobis-(Phihalic Acid) Derivatives

Reactions of 3,3′-thiobis(2,5-dihydrothiophene 1,1 dioxide) (2) with several dienophiles afforded Diels Alder adducts 4–7. Compound 7 was aromatized to give 4,4′-thio-bis(dimethyl phthalate) (9), a potential intermediate to sulfur- bridged polyimides.     

Functionalized 3,3′,5,5′‐Tetraaryl‐1,1′‐Biphenyls: Novel Platforms for Molecular Receptors

This paper describes the development of novel aromatic platforms for supramolecular construction. By the Suzuki cross‐coupling protocol, a variety of functionalized m‐terphenyl derivatives were prepared (Schemes 1–4). Macrolactamization of bis(ammonium salt) (S,S)‐ 6 with bis(acyl halide) 7 afforded the macrocyclic receptor (S,S)‐ 2 (Scheme 1), which was shown by ¹H‐NMR titration studies to form ‘nesting' complexes of moderate stability (K_a between 130 and 290 M ^?1, 300 K) with octyl glucosides 13 – 15 (Fig. 2) in the noncompetitive solvent CDCl₃. Suzuki cross‐coupling starting from 3,3′,5,5′‐tetrabromo‐1,1′‐biphenyl provided access to a novel series of extended aromatic platforms (Scheme 5) for cleft‐type (Fig. 1) and macrotricyclic receptors such as (S,S,S,S)‐ 1 . Although mass‐spectral evidence for the formation of (S,S,S,S)‐ 1 by macrolactamization between the two functionalized 3,3′,5,5′‐tetraaryl‐1,1′‐biphenyl derivatives (S,S)‐ 33 and 36 was obtained, the ¹H‐ and ¹³C‐NMR spectra of purified material remained rather inconclusive with respect to both purity and constitution. The versatile access to the novel, differentially functionalized 3,3′,5,5′‐tetrabromo‐1,1′‐biphenyl platforms should ensure their wide use in future supramolecular construction.