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1.
The bi[10]paracyclophane (−)-6b with two chiral planes and one chiral axis has been synthesized in enantiomerically pure form. Its absolute configuration was determined by quantum chemical calculation of the circular dichroism and comparison with the experimental CD spectrum.  相似文献   

2.
The synthesis of the bi[10]paracyclophanes 2 and 4 from the meso-configured bioxepine 3 is described. These compounds are stereochemically remarkable: the biaryl axis that connects the constitutionally identical, but oppositely configured planar-chiral paracyclophane portions, is configurationally semi-stable. Thus, 2 is an unprecedented borderline case of a (planar-chiral)-(axially chiral)-(planar-chiral) molecule that is right in between a meso-compound (as a macroscopical result of the—albeit slow—rotation about the central C,C-bond) and C1-symmetry (with respect to the existence of separable—even though configurationally unstable—discrete atropo-enantiomers). Despite their restricted configurational stability, these atropo-enantiomers were resolved on a chiral phase at 5 °C and were stereochemically assigned by LC-CD coupling, in combination with quantum chemical CD calculations.  相似文献   

3.
With the biggest cavity in the cucurbit[n]urils (CB[n]s) family, CB[10] has shown its unique molecular recognition properties. This review gives a brief summary of the research progresses in the CB[10]-based chemistry, involving its purification and applications in fields such as molecular recognition and molecular assembly.  相似文献   

4.
Proximal heteroalkylation of monoalkyl ethers of calix[4]arenes or p-tert-butylcalix[4]arenes in NaH/CH3CN or NaOH/DMSO, respectively, was applied for synthesis of inherently chiral calixarenes with ABHH substitution pattern. The introduction by the method of (R)- or (S)-N-(α-phenylethyl)acetamide chiral auxiliary group gives mixtures of diastereomeric derivatives of inherently chiral calixarenes, which were separated by column chromatography. The chiral calixarenes were thoroughly characterized by 1H, 13C NMR, and X-ray diffraction methods.  相似文献   

5.
The enantioselective synthesis of [9,9′]bi[naphtho(2,1-b)furanyl]-8,8′-diol, a modified BINOL, was achieved using an inexpensive route. Both enantiomers of [9,9′]bi[naphtho(2,1-b)furanyl]-8,8′-diol were obtained with satisfactory stereoselectivities by employing two optical antipodes of phenylethylamine as chiral influence in a Cu(II)Cl2 catalyzed oxidative coupling step.  相似文献   

6.
《中国化学快报》2023,34(3):107632
Here we use nor-seco-cucurbit[10]uril (ns-CB[10]) based ternary complexation to construct [5]rotaxane, linear supramolecular dynamic rotaxane polymers and cubic 3D supramolecular organic framework. A [5]rotaxane is constructed by ns-CB[10], TMeCB[6] and short linear derivatives of 4,4′-bipyridinium (M2). ns-CB[10], CB[7] and long linear derivatives of 4,4′-bipyridinium (M3) self-assemble into a linear supramolecular dynamic rotaxane polymer. ns-CB[10] and tetracationic tetrahedral monomer self-assemble and form a three-dimensional supramolecular organic framework. The above results demonstrate that ns-CB[10]-based ternary complexation is a versatile platform to build various supramolecular systems.  相似文献   

7.
《中国化学快报》2023,34(3):107780
The macrocyclic family comprising pillar[n]arenes and cucurbit[n]urils have received much attention recently. However, studies on the construction of supramolecular complexes formed directly with derivatized pillar[n]arenes and cucurbit[n]urils are scant. Given the interest in such systems, herein we have synthesized a new type of naphthalene-derivatized pillar[n]arene NTP5 and selected Q[10] as the host molecule. The 4-[2-(1-naphthalenyl)ethenyl]pyridine of NTP5 is encapsulated by Q[10] and formed a host-guest complex in water-acetic acid (1:1) solution accompanied by enhanced fluorescence, which changed the morphology of NTP5 from a sphere to a porous form. In addition, the fluorescence of Q[10]-NTP5 can be quenched by the addition of the highly toxic pesticide paraquat (PQ), and the mechanism was shown to be the formation of a new charge transfer ternary system of Q[10]-NTP5-PQ. This work provides new ideas for the contribution of supramolecular assemblies based on derivatized pillar[n]arenes and their combination with cucurbit[n]urils and reveals their potential applications.  相似文献   

8.
A meta-substituted aminocalix[4]arene 4 immobilized in the cone conformation was prepared via mercuration of the starting tetra-propoxy derivative, followed by nitrosation and reduction reactions. Acylation of the amino group by chiral amino acid residues ((S)-N-trifluoroacetyl-Ala or (S)-N-trifluoroacetyl-Phe) allowed for the preparation of diastereomeric amides that were separated by preparative TLC on silica gel. Subsequent cyclization under Bischler-Napieralski reaction conditions yielded calixarenes 7b and 7c bearing an oxazole moiety in the meta position instead of the expected upper rim-bridged compounds. The reaction sequence represents a straightforward approach towards enantiomerically pure inherently chiral calix[4]arene derivatives (without HPLC separation steps). The absolute configuration of the enantiomers were confirmed by single crystal structure determination (X-ray).  相似文献   

9.
《中国化学快报》2022,33(12):5124-5127
Challenges of achieving efficient photodimerization of azaanthracene derivatives remain due to the low selectivity and slow reaction rate. In this paper, cucurbit[10]uril (CB[10]), with the largest rigid and hydrophobic cavity among CB[n]s, was used to affect the photodimerization reaction of four water-soluble 1-(2-)substituted azaanthracene derivatives (1-4). It revealed that 1-4 could form 1:2 host-guest complexes with CB[10] in aqueous solution. Irradiation of 1 in the presence of 0.5 equiv. of CB[10] selectively produced a head-to-tail (anti-HT) photodimer product. As for 2-4, CB[10] acted as a nanoreactor accelerating their photodimerization reaction in water. Our results suggest that photodimerization of azaanthracene derivatives could be promoted by the CB[10]-based host-guest strategy with high efficiency and selectivity.  相似文献   

10.
The reductive coupling reaction of 1,4-bis(3-acetyl-5-tert-butyl-2-methoxyphenyl)butane 3 was carried out using TiCl4-Zn in pyridine followed by a McMurry coupling reaction to afford the compounds anti and syn 1,2-dimethyl[2.4]MCP-1-ene 4. Bromination of 4 with BTMA-Br3 in dry CH2Cl2 afforded the interesting compound 1,2-bis-(bromomethyl)-5,15-di-tert-butyl-8,18-dimethoxy[2.4]MCP-1-ene 6 and consecutive debromination with Zn and AcOH in CH2Cl2 solution afforded the stable solid 5,15-di-tert-butyl-8,18-dimethoxy-1,2-dimethylene[2.4]MCP 7 in 89% yield. Compound 7 was conveniently employed in a Diels–Alder reaction with dimethyl acetylenedicarboxylate (DMAD) to provide 2-(3′,6′-dihydrobenzo)-5,15-di-tert-butyl-8,18-dimethoxy[2.4]MCP-4′,5′-dimethylcarboxylate 8 in good yield. Diels–Alder adduct 8 was converted into a novel and inherently chiral areno-bridged compound [2.4]MCP 9 by aromatization. The chirality of the two conformers was characterized by circular dichroism (CD) spectra of the separated enantiomer which are perfect mirror images of each other.  相似文献   

11.
A chiral iridium complex catalyzed a consecutive and enantioselective [2+2+2] cycloaddition of polyynes to give axially chiral compounds. Intermolecular reaction of tetraynes, possessing aryl groups on their termini, with protected but-2-yne-1,4-diols gave C2-symmetrical quateraryl compounds. Intramolecular reaction of hexaynes, possessing aryl or alkyl groups on their termini gave C2-symmetrical biaryl compounds. The catalytic synthesis of a pentacene derivative with axial chiralities is also discussed.  相似文献   

12.
《中国化学快报》2023,34(10):108195
The effective removal and selective detection of explosive and toxic pollutant trinitrophenol (TNP) is an attractive but challenging field. Herein, a double-cavity nor-seco-cucurbit[10]uril (ns-Q[10])-based supramolecular assembly 8-HQ@ns-Q[10] was fabricated and its structure was characterized by X-ray single crystal diffraction. In this assembly, the stoichiometric ratio of ns-Q[10] and 8-hydroxyquinoline (8-HQ) is 1:2, which is also attributed to the special double-cavity structure of ns-Q[10]. The luminescence sensing experiments showed that 8-HQ@ns-Q[10] can be used as a good fluorescence-enhanced sensing material (enhanced 27-fold) for the rapid detection of explosives and the aqueous contaminant TNP, with a limit of detection (LOD) of 2.07 × 10−5 mol/L, without interference from other phenolic compounds. Furthermore, TNP can be efficiently removed in the presence of assembly 8-HQ@ns-Q[10], and the removal efficiency is more than 89%. Therefore, the supramolecular assembly 8-HQ@ns-Q[10], as a fluorescence-enhanced luminescence sensor and adsorption material, has rich research value and potential application prospect when applied to the detection and removal of TNP in aqueous environment.  相似文献   

13.
Potassium 2-methylthio-5-bromopyrimidine-4-carboxylate was condensed with thiophenoxide ion containing various electron releasing groups to produce 2-methylthio-5-arylthiopyrimidine 4-carboxylic acids. Some of these acids were cyclized through their acid chlorides with anhydrous aluminum chloride to their corresponding 10H-[1]benzothiopyrano[3.2—d]pyrimidin-10-ones.  相似文献   

14.
Summary The title compound was prepared from (–)(S) p -2,7-dibromo-1,6-methano[10]annulene by treatment withn-Bu-Li and subsequent quenching with D2O. The optical rotations at four wavelengths and the circular dichroism spectrum are reported.
Chiralität durch Deuterium-Substitution: Synthese und Circulardichroismus von (+)(R) p -2,7-Dideuterio-1,6-methano[10]annulen (Kurze Mitt.)
Zusammenfassung Die Titelverbindung wurde aus (–)(S) p -2,7-Dibrom-1,6-methano[10]annulen durch Umsetzung mitn-Bu-Li und nachfolgende Reaktion mit D2O dargestellt. Optische Rotationen bei vier Wellenlängen und das Circulardichroismus-Spektrum wurden bestimmt.
  相似文献   

15.
We have developed an efficient chemical resolution of racemic hydroxy substituted dithia-aza[4]helicenes (DTA[4]H) 1(OH) using enantiopure acids as resolving agents. The better diastereomeric separation was achieved on esters prepared with (1S)-(−)-camphanic acid. Subsequent simple manipulations produced highly optically pure (≥ 99% enantiomeric excess) (P) and (M)-1(OH) in good yields. The role of the position where the chiral auxiliary is inserted (cape- vs. bay-zone) and the structure of the enantiopure acid used on successful resolution are discussed.  相似文献   

16.
[n]Helicenes with helically twisted structures have attracted increasing interest owing to their unique properties. Therefore, it has been an important issue to develop facile synthetic methodologies which allow access to a variety of [n]helicenes. Here we report the synthesis of [7]helicenes and [7]helicene-like compounds from the thia[7]helicene as a common starting material. Desulfurative dilithiation of the thia[7]helicene and the subsequent reaction with silicon and phosphorus electrophiles afforded the silole- and phosphole-fused [7]helicene-like compounds, respectively. The cyclopentadiene-fused [7]helicene-like compound and the pyrrole-fused aza[7]helicenes were also successfully synthesized via twofold SNAr reactions of the thia[7]helicene S,S-dioxide with the carbon and nitrogen nucleophiles, respectively. The thia[7]helicene S,S-dioxide showed a slightly red-shifted absorption spectrum than the parent thia[7]helicene, which was well demonstrated by the theoretical calculations. The substituents on the silicon atom of silole-fused [7]helicene-like compounds have little impact on the longest absorption maximum. Such little effect of the substituents on absorption properties was also observed for cyclopentadiene-fused [7]helicene-like compounds and aza[7]helicenes and was well demonstrated by the theoretical calculations. The thia[7]helicene S,S-dioxide and the silole-fused [7]helicene-like compound exhibited bright blue emission, and the cyclopentadiene-fused [7]helicene-like compound and the aza[7]helicenes showed strong violet emission. Each single enantiomer of the aza[7]helicenes showed circularly-polarized luminescence with the dissymmetry factors of 4.2~4.4 × 10−3.  相似文献   

17.
Various 2-alkoxy 7-chloro-10-[[[(dialkylamino)alkyl]amino]]benzo[b][1,5]naphthyridines (XI) and N-oxides (XV, XVII, XVIII, XXII), 4-[(2-alkoxy-7-chlorobenzo[b][1,5]naphthyridin-10-yl)-amino]-α-(diethylamino)-o-cresol derivatives (XII-XIV, XXI) and N-oxides (XIX, XX, XXV), 2-butoxy-8-[[[(dialkylamino)alkyl]amino]]-1,5-naphthyridines (XXVIa and b), and 2-butoxy-8–[[3-[(diethylamino)methyl]-p-anisidino]]-1,5-naphthyridine (XXVII) were synthesized for antifilarial and antimalarial evaluation. The compounds were obtained in 13–91% yield by the condensation of 2-alkoxy-7,10-dichlorobenzo[b][1,5]naphthyridines, 2-alkoxy-7,10-dichlorobenzo[b][1,5]naphthyridine 5-oxides, and 2-butoxy-8-chloro-1,5-naphthyridine with the appropriate diamine in phenol, or by perbenzoic acid oxidation of the parent 10-amino-7-chlorobenzo-[b][1,5] naphthyridines in chloroform. Among them, eight compounds killed adult Litomosoides carinii in gerbils when administered in daily gavage doses of 25–400 mg./kg. for 5 days. Azacrine 5-oxide (XVII), the most active compound, was equipotent with amodiaquine (1a), azacrine (IX), and quinacrine 10-oxide (VI). Twelve substances were active orally against Plasmodium berghei in mice at doses ranging from 3.8–155 mg./kg./day for 6 days. 7-Chloro-10-[[-3-[(diethylamino)-methyl]-p-anisidino]]-2-methoxybenzo[b][1,5]naphthyridine 5-oxide dihydrochloride (XX) was approximately 12 times as potent as quinine against P. berghei, but was highly cross-resistant with chloroquine (IV). Structure-activity relationships are discussed.  相似文献   

18.
Planar chiral [2]‐ and [3]rotaxanes constructed from pillar[5]arenes as wheels and pyridinium derivatives as axles were obtained in high yield using click reactions. The process of rotaxane formation was diastereoselective; the obtained [2]rotaxane was a racemic mixture consisting of (pS, pS, pS, pS, pS) and (pR, pR, pR, pR, pR) forms of the per‐ethylated pillar[5]arene ( C2 ) wheel, and other possible types of the [2]rotaxane did not form. Isolation of the enantiopure [2]rotaxanes with one axle through (pS, pS, pS, pS, pS)‐ C2 or (pR, pR, pR, pR, pR)‐ C2 wheels was accomplished. Furthermore, pillar[5]arene‐based [3]rotaxane was successfully synthesized by attachment of two pseudo [2]rotaxanes onto a bifunctional linker. [3]Rotaxane formed in a 1:2:1 mixture with one axle threaded through two (pS, pS, pS, pS, pS)‐ C2 , one (pS, pS, pS, pS, pS)‐ C2 and one (pR, pR, pR, pR, pR)‐ C2 (meso form), or two (pR, pR, pR, pR, pR)‐ C2 wheels. The [3]rotaxane enantiomers and the meso form were successfully isolated using appropriate chiral HPLC column chromatography. The procedure developed in this study is the starting point for the creation of pillar[5]arene‐based interlocked molecules.  相似文献   

19.
The synthesis and characterization of a series of regioselective intramolecular bridging of calix[10]arene are described for the first time. Reacting p-tert-butylcalix[10]arene with tri-ethylene glycol ditosylate using K2CO3 as a base in toluene, 1,2-calix[10]crown-4 2a, 1,4-calix[10]crown-4 2b and 1,6-calix[10]crown-4 2c were obtained in yields of 9%, 14% and 7%, respectively. While using Cs2CO3/acetone instead of K2CO3/toluene, the 1,4-calix[10]crown-4 2b was obtained selectively in good yield up to 50%.  相似文献   

20.
Chiral diastereomeric cavitand-salen macrocycles have been synthesized by the high-dilution condensation of a tris-(quinoxaline-bridged)-diformyl-calix[4]resorcarene with (1R,2R)-diphenylethylenediamine. The reaction produced a couple of diastereoisomers, consisting of two cavitand cavities bis-bridged by two chiral diimino moieties, which differ in a convergent (C-shaped) or divergent (S-shaped) orientation of the two cavities.  相似文献   

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