一种吲哚螺吡咯多取代杂环化合物的合成及其晶体结构

利用多组分1,3偶极环加成反应方法,合成了一种新的螺环结构1'-甲基-3'-吡啶甲酰基-4'-(2-噻吩基)螺[吲哚啉-3,2'-吡咯啉]-2-酮化合物,并对该化合物进行了红外光谱、核磁共振谱及X-射线单晶衍射表征.单晶衍射结果表明:该晶体属于三斜晶系,空间群为P-1,晶体参数为a=0.899 9(1)nm,b=0.914 4(1)nm,c=1.271 1(2)nm,α=92.852(1)°,β=107.305(2)°,γ=101.580(1)°.在分子晶体结构中,吡咯啉环采用了信封式构象,通过螺碳原子与吲哚啉环相连,形成刚性螺环结构,2个环接近垂直构型,其二面角为84.15(2)°.     

Synthesis,structure and antioxidant activity of sulfur-containing tetrakisphenol

3-[2-(3,5-Di-tert-butyl-4-hydroxyphenylsulfanyl)acetoxy]2,2-bis[2-(3,5-di-tert-butyl-4-hydroxyphenylsulfanyl) acetoxymethyl]propyl 3,5-di-tert-butyl-4-hydroxyphenylsulfanylacetate was synthesized. Its structure was determined by means of ¹H and ¹³C NMR spectroscopy and X-ray-diffraction analysis. This compound was found to possess high antioxidant activity in the conditions of auto-oxidation of low-pressure polyethylene.     

Microbiological transformations—XII: Microbiological reduction of racemic 1-(2',2',3'-trimethyl-cyclopent-3'-en-1'-yl)propan-2-one and 1-(2',2',3'-trimethyl-cyclopent-3'-en-1'-yl)butan-2-one by rhodotorula mucilaginosa

The microbiological reduction of (±)-l-(2',2',3'-trimethylcyclopent-3'-en-l'-yl)-propan-2-one (4) and (±)-1-(2',2',3'-trimethylcyclopent-3'-en-l'-yl)-butan-2-one (5) by Rhodotorula mucilaginosa was investigated. Both enantiomers of 4 are reduced stereospecifically to corresponding alcohols; (+)-(2S, l'R)-(2',2',3'-trimethylcyclopent-3'-en-l'-yl)-propan-2-ol (6) and (-)-(2S,l'S)-(2',2',3'-trimethylcyclopent-3'-en-l'-yl)-propan-2-ol (7). p ]The substrate selectivity in the reduction of 5 was observed: R enantiomer of 5 yields stereospecifically (+)-(2S,1'R)-(2',2',3'-trimethylcyclopent-3'-en-l'-yl)-butan-2-ol (8) while S(-)5 remains unchanged.     

新型螺双二氢茚二酚衍生物的合成

螺双二氢茚二酚(SPINOL)与N-溴代丁二酰亚胺经溴代反应制得6,6'-二溴-螺双二氢茚二酚(1);1与叔丁基二甲基硅基三氟甲磺酸(TBSOTf)经醚化反应得6,6'-二溴-7-羟基-7'-叔丁基二甲硅氧基-1,1'-螺二氢茚(2);SPINOL经羟基保护后与碘甲烷经双甲基化反应制得6,6'-二甲基-7,7'-双(1-甲氧甲氧基)-1,1'-螺二氢茚(4);4经脱保护后再与TBSOTf经醚化反应合成了6,6'-二甲基-7-羟基-7'-叔丁基二甲硅氧基-1,1'-螺二氢茚(6)。2和6为新化合物,其结构经1H NMR,13C NMR和HR-ESI-MS表征。     

荧光探针2-硼酸基苯甲醛-(2′-羟基-4′-磺酸基)萘腙的合成及对Pb~(2+)的识别

设计合成了2-硼酸基苯甲醛-(2′-羟基-4′-磺酸基)萘腙衍生物(2-BBHSNH),该化合物水溶性极好,识别体系不需任何有机介质。在pH=6.0的KH2PO4-NaOH缓冲溶液中,2-BBHSNH对Pb2+具有选择性识别作用,主客体分子间形成1∶1型的发光配合物。该配合物最大发射波长为568nm,稳定常数为4.3×104 L·mol~(-1)。荧光强度的变化值与Pb~(2+)浓度在5.0×10-7~1.0×10-4 mol·L~(-1)范围内呈现良好的线性关系,相关系数R=0.9983,检出限为9.7×10-8 mol·L~(-1)。将该方法用于环境水样中Pb2+的测定,回收率为111%~116%。     

2'-deoxyribonucleoside 3'-aryl phosphoranilidates: Key intermediates in the stereospecific synthesis of 2'-deoxyribonucleoside cyclic 3',5'-phosphorothioates and dinucleoside(3'→5')-phosphoranilidates

Phosphorylation of the 5'-O-monomethoxytrityl-2'-deoxyribonucleosides by means of aryl phosphoranilidochloridates gives the diastereoisomers of 5'-O-monomethoxytrityl-2'-deoxyribonucleoside 3'-aryl phosphoranilidates. Their separation can be performed by means of chromatographic techniques. They can be further converted to the 2'-deoxyribonucleoside cyclic 3'-5' phosphoranilidates, which are intermediates in the stereospecific synthesis of 2'-deoxyribonucleoside cyclic (3'-5')phosphorothioates of known absolute configuration at phosphorus.     

Synthesis of 2'-deoxy-1-deazawyosine: A stabile 2'-deoxyisostere of a rare trna constituent

2'-Deoxy-1-deazawyosine (3a), an isostere of the rare tRNA constituent wyosine (la) and its α-anomer have been synthesized via glycosylation of the nucleobase 5a with the halogenose 6. In contrast to the labile parent 1a, the isostere is highly stabile against hydrolysis even as 2'-deoxynuclcoside. The stability of 3a is due to the low susceptibility of the pyrrol ring to protonation. The rapid hydrolysis of wyosine (la) compared to guanosine is explained by a favoured solvatization of the molecule being freezed in the anti-conformation.     

An efficient synthesis of certain 5-substituted-2'-deoxyuridine 3',5'-cyclic monophosphate p-o-alkyl(aralkyl) esters. The crystal and molecular structure of 5-IODO-2'-deoxyuridine 3',5'-cyclic monophosphate p-o-methyl ester with axial methoxy group

Some 5-alkyl- and 5-halogeno-2'-deoxyuridine 3',5'-cyclic mono- phosphate P-O-alkyl(aralkyl) esters have been prepared from the silver salts of the parent cyclic monophosphates and alkyl(aralkyl) iodides. The diastereomeric phosphotriesters have been characterized by spectroscopic methods. The crystal and molecular structure of 5-iodo-2'-deoxyuridine 3',5'-cyclic monophosphate P-O-methyl ester with axial methoxy group has been determined. We failed to obtain the desired triesters from the reactions of the cAMP silver salt with alkyl iodides, contrary to previous claims in the literature.     

(S)-5,5'-二氨基-2,2'-双二苯基膦基-1,1'-联萘的绿色合成

以2,2'-双二苯基磷基-1,1'-联萘[(S)-1]为原料,与H2O2经氧化反应制得(S)-2,2'-双二苯基磷氧基-1,1'-联萘[(S)-2];(S)-2经酸性树脂催化硝化制得(S)-5,5'-二硝基-2,2'-双二苯基磷氧基-1,1'-联萘[(S)-3)];(S)-3经Pd/C催化硝基氢化还原制得(S)-5,5'-二氨基-2,2'-双二苯基磷氧基-1,1'-联萘[(S)-4];(S)-4经HSi Cl3/PPh3还原制得(S)-5,5'-二氨基-2,2'-双二苯基膦基-1,1'-联萘,总产率65.6%,其结构经1H NMR,31P NMR和IR确证。     

1H-NMR-spektroskopische konformationsanalyse von halogenierten thymidinabkömmlingen: I. konformation von thymidin, 3',5'-didesoxy-3'-chlor-5'-fluor-thymidin und 3', 5'-didesoxy-3',5'-difluor-thymidin

An improved method is given for determining the conformation of furanoid nucleosides by ¹H-NMR-spectra analysis using halogen-substituted thymidines as examples. The state of the three equilibria - ring-puckering, rotation about the C₄-C₅- bond and about the glycosidic bond - are influenced by the halogen substituents. Compared with thymidine the 3'-chlorine substituent shifts the furanose conformation to conformers, where the 3'-chlorine substituent is equatorial. The 5'-fluorine substituent increases the contribution of the G-G-rotamer and the ratio of syn-conformation. The relationships between the conformers in the pseudo-rotatory cycle and the population of the C_4'-C_5' rotamers are discussed.     

Synthesis, structure, and antioxidant activity of hybrid N-substituted salicylic acid amides

Sterically hindered phenols, 3-tert-butyl-N-(3,5-di-tert-butyl-4-hydroxyphenyl)-5-ethyl-2-hydroxybenzamide and N-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propyl]-2-hydroxybenzamide, were synthesized as potential antioxidants, and the formation of hydrogen bonds by their molecules was shown by UV and IR spectroscopy.     

2,6-双(1-苄基-2-苯并咪唑基)吡啶的合成、晶体结构、光谱及抗氧化活性

合成了化合物2,6-双(1-苄基-2-苯并咪唑基)吡啶,通过元素分析、红外光谱、核磁共振氢谱和X-射线单晶衍射方法对其结构进行了表征.结构分析表明,该晶体属于单斜晶系,C2/c空间群,晶胞参数a=2.989 30(15) nm,b=1.093 74(5) nm,c=1.578 86(7) nm, β=103.555(5)o,V=5.018 32(42) nm3,Z=8,Dc=1.301 g/cm3,μ(Mo-Kα)=0.079 mm-1,F(000)=2 064,S=1.038,R1=0.046 0,w R2=0.127 9,化合物分子间存在的C—Hπ和苯环ππ堆积作用,使得其沿b轴方向形成了一维链状结构.通过紫外-可见吸收和荧光光谱研究了化合物的光谱性质及其对DPPH自由基的抗氧化活性.     

Decarboxylation,during their aromatization by Pd/C,of some 3,4-octahydronaphtho-7,8-benzocoumarins : Synthesis of 1,2'-binaphthyls and 2,2'-binaphthyls

Some 3',4'-cyclohexa-1',2'-dihydro- and 1',2'-cyclohexa-3',4'-dihydro-3,4,7,8-dibenzocoumarins 2 and 3 were prepared by catalytic condensation between a naphthol and a α-carbethoxy-cis- decalone (?1 or ?2). These compounds, when treated with Pd/C at 260°, undergo, beside aromatization, a complete decarboxylation of the lactone ring. A mechanism, involving H transfer through a π-allylic palladium complex is described.     

Synthesis, characterization and antioxidant activity copper-quercetin complex

Quercetin (3,3',4',5,7-pentahydroxyflavone) one of the most abundant dietary flavonoids, has been investigated in the presence of Cu(II) in methanol. The spectroscopic studies (UV-vis, (1)H NMR and IR) were useful to assess the relevant interaction of Quercetin with Cu(II) ions, the chelation sites and dependence of the complex structure from the metal/ligand ratio. A 1:2 (L:M) complex was indicated by Job's method of continuous variation, which was applied to ascertain the stoichiometric composition of the complex. The antioxidant activities of the compounds were evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. The complexed flavonoid was much more effective free radical scavengers than the free flavonoids.