Chiral ionic liquid-mediated photochirogenesis. Enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid

Enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid (AC-H) and its lithium salt (AC-Li) in chiral ionic liquid (CIL), (R)-1-(2,3-dihydroxypropyl)-3-methylimidazolium acetate {[(R)-GLYMI][AcO]}, gave a mixture of two head-to-tail (HT) and two head-to-head (HH) cyclodimers in HT/HH ratios of 1.3-1.7 (for AC-H) and 2.2-4.3 (for AC-Li) with low enantiomeric excesses (ee) of 0-3% for chiral syn-HT and anti-HH dimers. In contrast, irradiation of AC-H in an aqueous solution, containing cucurbit[8]uril (CB[8]) as a host and [(R)-GLYMI][AcO] or [(R)-GLYMI][Tf(2)N] as a modifier of CB portals, afforded the HH dimers in 91-99% selectivity, although the anti-HH dimer was totally racemic. Interestingly, irradiation of AC-H in a dichloromethane solution, containing [(R)-GLYMI][AcO] as a chiral template, led to the formation of the HH-dimers in 98% selectivity with chiral anti-HH dimer in -14% ee, presumably by the dual ligation of two ACs to a CIL through electrostatic and hydrogen-bonding interactions.     

Enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid mediated by gamma-cyclodextrins with a flexible or rigid cap

[reaction: see text] A series of modified gamma-cyclodextrins (CDs) with a flexible or rigid cap, synthesized and used as chiral supramolecular hosts for mediating the enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid, significantly improved the chemical and optical yields of chiral head-to-head cyclodimer 3, while the gamma-CD with a rigid cap dramatically inverted the stereochemical outcomes and further improved the enantioselectivities of both head-to-tail and head-to-head dimers 2 and 3.     

Template-assisted stereoselective photocyclodimerization of 2-anthracenecarboxylic acid by bispyridinio-appended gamma-cyclodextrin

[reaction: see text] Four kinds of bispyridinio-appended gamma-cyclodextrin (gamma-CD) were prepared to make a molecular flask for controlling the stereoselectivity of photocyclodimerization of 2-anthracenecarboxylate. When the photocyclodimerization of 2-anthracenecarboxylate was carried out in the presence of A,E-bispyridinio-appended gamma-CD, the relative yield of one of the configurational isomers, the head-to-head/anti-isomer, was increased 1.8-fold compared to the corresponding yield in the presence of unmodified gamma-CD or in the absence of any gamma-CD. The optical yields of the photocyclodimerization reaction products also increased more than 10-fold by the addition of bispyridinio-appended gamma-CD compared with unmodified gamma-CD.     

Synthesis and pharmacological activity of 4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2-hydroxymethyl-4- pyrrolidinyl]benzamide (TKS159) and its optical isomers

Of 4-amino-5-chloro-2-methoxy-N-(1-ethyl-2-hydroxymethyl-4- pyrrolidinyl)benzamide, four optical isomers, (2S,4S)-1 (TKS159), (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27, were prepared from optically active 4-amino-1-ethyl-2-hydroxymethylpyrrolidine di-p-toluenesulfonate [(2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-23, respectively]. The requisites, (2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-23, were prepared from a commercially available trans-4-hydroxy-L-proline. The absolute configurations of (2S,4S)-1 (TKS159), (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27 were spectroscopically determined. Of the benzamide derivatives, four optical isomers, (2S,4S)-1, (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27, showed a relatively potent affinity for 5-hydroxytryptamine 4 (5-HT4) receptors in a radioligand binding assay ([3H]GR113808). The activities of 25-27 were less effective than that of 1 for the gastric emptying of a phenol red semisolid meal in rats. All this suggests that the most potent of the isomers was 4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2- hydroxymethyl-4-pyrrolidinyl]benzamide (1).     

Enantiodifferentiating [2+2] photocycloaddition of cyclohexenone carboxylic acid with ethylene using 8-phenylmenthyl amine as a chiral template

Enantiodifferentiating [2+2] photocycloaddition of cyclohexenone carboxylic acid with the smallest olefin, ethylene, was accomplished using 8-phenylmenthyl amine as a chiral template. Particularly, we succeeded in enhancing the enantiomeric excess (ee) value by selective excitation of a chiral substrate–template supramolecular complex.     

N-(2-(取代苯并噻唑-2-氨基甲酰基)-取代苯基)-4-氟苯甲酰胺衍生物的合成及生物活性

以对氟苯甲酸和取代邻氨基苯甲酸为起始原料,设计并合成11个含氟基苯并噻唑基邻甲酰氨基苯甲酰胺类化合物,其结构经1 H NMR、13C NMR、IR及元素分析确证.初步生物活性测试结果表明,在500 mg/L浓度下部分化合物对烟草花叶病毒(TMV)有一定抑制作用.采用MTT法进行化合物抑制PC3及Bcap-37癌细胞体外活性测试,结果表明所合成的化合物具有不同程度的抑制PC3和Bcap-37癌细胞活性,其中化合物4d在10 μmol·L-1浓度下对PC3和及Bcap-37的抑制率分别为73.2％和68.1％.     

Synthesis and complexing ability of N-[2-(2-morpholinoacetyl)hydrazinocarbothioyl]benzamide

The synthesis and identification of N-[2-(2-morpholinoacetyl)hydrazinocarbothioyl]benzamide were performed. A qualitative and quantitative evaluation of its complexing ability to the Ni(II) and Co(II) ions was done. The stability constants of the Ni- and Co-complexes were determined. The thermodynamic aspects of the complexing process were discussed.     

A solid-state fluorescence sensing system consisting of chiral (1R,2S)-2-amino-1,2-diphenylethanol and fluorescent 2-anthracenecarboxylic acid

A solid-state fluorescence sensing system was created by using a chiral supramolecular organic fluorophore having a channel-like cavity composed of (1R,2S)-2-amino-1,2-diphenylethanol as a chiral molecule and 2-anthracenecarboxylic acid as a fluorescence molecule.     

Synthesis and Crystal Structure of N-(2-(1-butyl-3-phenylureido)-1H-indol-3-yl)-N-(4-chlorophenyl)benzamide

<正>The title compound N-(2-(1-butyl-3-phenylureido)-1H-indol-3-yl)-N-(4-chloro- phenyl)- benzamide (C_(32)H_(29)ClN_4O_2, M_r = 537.04) was synthesized by a sequential Ugi four com- ponent condensation (4CC)/aza-Wittig/carbodiimide-mediated cyclization, and the structure was characterized by NMR, IR, MS, elemental analysis and X-ray single-crystal diffraction analysis. The crystal belongs to orthorhombic, space group P2_12_12_1 with a = 11.3663(9), b = 13.3248(10), c = 18.7887(15), V = 2845.6(4)~3, Z = 4, D_c = 1.254 mg/m3, μ = 0.170 mm~(-1), F(000) = 1128, the final R = 0.0538 and wR = 0.1187. X-ray analysis reveals that the new five-membered ring (C(14)-C(15)-N(2)-C(16)-C(21)) and the benzene ring (C(16)-C(21)) are nearly coplanar.     

Complexing ability of N-[2-(2-morpholinoacetyl)hydrazinocarbothioyl]benzamide toward iron(II) ions

Qualitative and quantitative assessment of the complexing ability of N-[2-(2-morpholinoacetyl)-hydrazinocarbothioyl]benzamide toward iron(II) ions is given. Stability constants of iron(II) complexes are determined. Thermodynamics of the complex-formation processes is considered.     

Synthesis of N-(2-Benzene-2,2-dichloroethylidene)-4-chlorobenzenesulfonamide and N-(2-Benzene-2,2- dichloroethylidene)-4-methylbenzenesulfonamide

In reaction of N,N-dichloro-4-chlorobenzene- and N,N-dichloro-4-methylbenzenesulfonamides with phenylacetylene were obtained in good yield N-(2-benzene-2,2-dichloroethylidene)arenesulfonamides. The latter undergo nucleophilic addition of water, ethanol, and arenesulfonamides.     

N-[2-(4-Methoxy-phenyl)-ethyl]-2-(quinolin-8-yloxy)acetamide: a receptor for acid binding

Different hydrates of the receptor, N-[2-(4-methoxy-phenyl)-ethyl]-2-(quinolin-8-yloxy)acetamide (I), and its co-crystals with acetic acid and l(+)α-hydroxy-phenylacetic acid are synthesised and their structures are studied. The acids such as acetic acid, l(+)α-hydroxy-phenylacetic acid quench fluorescence of I. The receptor I shows a fluorescence quenching on interaction with perchloric acid in benzene, whereas in methanol the solution of I results in the generation of a new fluorescence emission at higher wavelengths. The crystal structure of the perchlorate salt is determined to explain the protonation behaviour of the receptor I and the perchlorate salt in methanol leads to fluorescence emission at a place different from that of the parent compound.     

N-(4-哌啶基)苯甲酰胺衍生物的设计、合成及其抗肝癌活性

以4-羟基苯甲酸乙酯为原料,经烃化、水解、缩合、脱保护、磺酰化反应,合成了6个含有磺酰基取代的4-苯氧基-N-(4-哌啶基)苯甲酰胺衍生物。 其结构经¹H NMR、¹³C NMR和MS谱等技术手段进行了表征,并以索拉非尼为阳性对照药对HepG2细胞株进行了初步体外抗肝癌细胞增殖活性的评价。 实验发现,4-苯氧基-N-(1-甲磺酰基哌啶-4-基)苯甲酰胺的体外抗肝癌生物活性优于索拉非尼,IC₅₀值为8.42 μmol/L。 研究结果表明,新结构4-苯氧基-N-(4-哌啶基)苯甲酰胺类化合物具有良好的抗肝癌活性。     

Synthesis of 2-(5-hydroxymethyl-2-formylpyrrol-1-yl)propionic acid lactone

2-(5-Hydroxymethyl-2-formylpyrrol-1-yl)propionic acid lactone was synthesized in six steps with a 17.0% overall yield, starting from L-alanine. The synthetic route involved the Clauson-Kaas reaction, Vilsmeier reaction, and transesterification. The transesterification was the key step in the formation of the target compound.