α-{[4-(取代苯基亚甲基)亚氨基]苯氧基}丙酸乙酯的合成及植物生长调节活性

通过4．氨基苯氧丙酸乙酯与相应的取代芳香醛类化合物进行缩合反应得到了11个未见报道的α-{[4-(取代苯基亚甲基)亚氨基]苯氧基}丙酸乙酯类目标化合物,用UV、IR、~1H NMR和元素分析测试技术对其进行了表征。探讨了芳环上取代基对反应收率的影响,结果发现具有吸电子取代基的对硝基苯甲醛给出93％的最高反应产率:而有供电子取代基的对甲基苯甲醛给出54％的最低反应产率。初步生物活性测试证明,此类席夫碱化合物具有一定的植物生长调节活性:化合物6b和6f具有52％和55％的促黄瓜子叶生根活性,化合物6j具有75％的黄瓜子叶生根抑制活性;化合物6h具有53％的生长素活性;化合物6b具有51％的细胞分裂素活性。     

含噻吩和吡啶基的插烯式四硫富瓦烯衍生物的合成、结构和电化学性质

在亚磷酸三乙酯催化作用下,2,3-二(2-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(1)分别与2-噻吩甲醛(2a)和3-噻吩甲醛(2b)发生成烯偶联反应,生成二硫富瓦烯化合物[2-(2-噻吩)亚基-1,3-二硫环戊烯-4,5-二硫基]双邻吡啶(3a)和[2-(3-噻吩)亚基-1,3-二硫环戊烯-4,5-二硫基]双邻吡啶(3b);含噻吩和吡啶基的二硫富瓦烯化合物3a和3b分别经过单质碘诱导氧化偶联反应和硫代亚硫酸钠还原反应,得到含噻吩和吡啶基的插烯式四硫富瓦烯化合物1,2-双(4,5-二邻吡啶硫代-1,3-二硫环戊烯-2-亚基)-1,2-双(2-噻吩基)乙烷(4a)和1,2-双(4,5-二邻吡啶硫代-1,3-二硫环戊烯-2-亚基)-1,2-双(3-噻吩基)乙烷(4b).利用核磁共振波谱(NMR)、傅里叶变换红外光谱(FTIR)和质谱(MS)方法对插烯式四硫富瓦烯衍生物(4a和4b)分别进行了表征,同时采用X射线单晶衍射法分析确证了化合物3a,3b,4a和4b的晶体结构.循环伏安法研究结果表明,化合物4a和4b呈现准可逆的两电子转移行为.结合量子化学理论计算,探讨了噻吩基的位置差异对化合物4a和4b电化学电位的影响.     

3-杂环基硫取代-1,3,4,5-四氢-2-氧代-苯并氮杂衍生物的合成

以芳酰肼为原料, 合成了一系列3-巯基-5-芳基-1,2,4-三唑、2-巯基-5-芳基-1,3,4-噁二唑和2-巯基-5-芳 基-1,3,4-噻二唑, 并通过硫原子对3-溴-2-氧代-苯并氮杂3-位上的亲核取代反应将杂环化合物引入了苯并氮杂的结构当中, 合成了32个新的苯并氮杂杂环衍生物. 为提高其在有机溶剂中的溶解性, 在苯并氮杂的N原子上引入乙酸乙酯和乙酸叔丁酯基取代基, 合成了36个新衍生物. 所有化合物经质谱、核磁共振谱及元素分析确证了结构并初步测定了抗菌活性.     

3-杂环基硫取代-1,3,4,5-四氢-2-氧代-苯并氮杂衍生物的合成

以芳酰肼为原料,合成了一系列3-巯基-5-芳基-1,2,4-三唑、2-巯基-5-芳基-1,3,4-噁二唑和2-巯基-5-芳基-1,3,4-噻二唑,并通过硫原子对3-溴-2-氧代-苯并氮杂3-位上的亲核取代反应将杂环化合物引入了苯并氮杂的结构当中,合成了32个新的苯并氮杂杂环衍生物.为提高其在有机溶剂中的溶解性,在苯并氮杂的N原子上引入乙酸乙酯和乙酸叔丁酯基取代基,合成了36个新衍生物.所有化合物经质谱、核磁共振谱及元素分析确证了结构并初步测定了抗菌活性.     

2，6-二-O-乙氧乙基-3-O-三氟乙酰基-β-环糊精气相色谱手性固定相的制备及应用

将β-环糊精的2,6-位引入乙氧乙基,3-位引入三氟乙酰基,合成了新的环糊精衍生物2,6-二-O-乙氧乙基-3-O-三氟乙酰基-β-环糊精,并采用静态法涂渍毛细管气相色谱柱,考察了毛细管柱的柱性能和分离性能。结果表明,该固定相对G rob试剂、苯的二取代位置异构体氯甲苯、硝基甲苯和溴甲苯以及10种手性化合物如α-取代丙酸酯化合物、1-(2′-硝基苯基)-乙醇、α-甲基-对氯苯乙腈和丙炔醇酮乙酸酯等具有良好的分离效果。其中,对α-甲磺酰基丙酸酯对映体的拆分效果最好;对α-取代丙酸的甲酯衍生物的分离效果优于乙酯衍生物;对α-羟基取代丙酸酯的分离效果优于α-卤代丙酸酯。     

含吡啶基四硫富瓦烯衍生物的合成、 结构和电化学性质

在乙酰乙酸乙酯和氧化亚铜共同催化下, 二-(1,3-二硫环戊烯-2-硫酮-4,5-二硫)合锌酸四乙基铵盐分别与2-碘吡啶(1a)、 3-碘吡啶(1b)和4-碘吡啶(1c)反应, 制得硫酮化合物2,3-二(2-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(2a)、 2,3-二(3-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(2b)和2,3-二(4-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(2c). 在醋酸汞催化下, 硫酮化合物2a, 2b和2c分别被氧化为2,3-二(2-吡啶硫基)-1,3-二硫环戊烯-2-酮(3a)、 2,3-二(3-吡啶硫基)-1,3-二硫环戊烯-2-酮(3b)和2,3-二(4-吡啶硫基)-1,3-二硫环戊烯-2-酮(3c). 以亚磷酸三乙酯为偶联剂, 氧酮化合物3a, 3b和3c分别发生自偶联反应生成2,3,6,7-四(2-吡啶硫基)四硫富瓦烯(4a)、 2,3,6,7-四(3-吡啶硫基)四硫富瓦烯(4b)和2,3,6,7-四(4-吡啶硫基)四硫富瓦烯(4c). 采用核磁共振波谱(NMR)、 傅里叶变换红外光谱(FTIR)和质谱(MS)分析了所合成化合物的结构和组成, 通过X射线衍射分析确认了吡啶基四硫富瓦烯衍生物4b和4c的晶体结构. 循环伏安法研究结果表明, 化合物4a, 4b和4c呈现准可逆的两电子转移过程, 结合量子化学计算, 分析了不同位置取代的吡啶基对四硫富瓦烯电化学电势的影响.     

一些新型含氮、硫杂官能团的杯[4]芳烃衍生物的合成

以杯[4]芳烃-1,3-二溴乙氧基衍生物1为合成平台,在K2CO3/MeCN体系中分别与乙醇胺、L-亮氨醇、2-巯基苯并咪唑、巯基乙酸乙酯反应,以49%～76%的产率合成了4种新型含氮、硫杂官能团的杯[4]芳烃衍生物2,4,5和6.化合物2进一步与异硫氰酸苯酯反应,以84%的产率得到了新型树枝状杯[4]芳烃氮、硫杂衍生物3.新化合物的结构与构象经元素分析、质谱、核磁共振谱等表征证实.     

5-氨基-1H-1,2,4-三氮唑-3-硫代-2''''-丙酸乙酯类Schiff碱的合成与表征

用氨基三氮唑硫代丙酸乙酯与取代苯甲醛反应,合成了6个新型的5-氨基-1H-1,2,4-三氮唑-3-硫代-2′-丙酸乙酯类Schiff碱,其结构经1H NMR, IR, MS和元素分析表征.     

合成宾达利的新方法

以邻氨基苯乙酮(2)为原料,经过连续的重氮化-还原-缩合反应序列制得3-甲基-1H-吲唑(3);3经(Boc)2O保护亚氨基后以NBS进行甲基溴代反应制得1-叔丁氧羰基-3-溴甲基-1H-吲唑(5);5与2-羟基异丁酸乙酯缩合得醚2-(1-叔丁氧羰基-1H-吲唑-3-基)甲氧基-2-甲基丙酸乙酯(6);6经HCl/乙酸乙酯溶液脱Boc保护制得关键中间体7;在叔丁醇钾存在下,7与溴苄缩合并水解合成了MCP-1抑制剂宾达利,总收率37.3%,其结构经1H NMR,13C NMR和MS确证。     

5-氨基-1H-1，2，4-三氮唑-3-硫代-2′-丙酸乙酯类Schiff碱的合成与表征

用氨基三氮唑硫代丙酸乙酯与取代苯甲醛反应，合成了6个新型的5-氨基-1H-1，2，4-三氮唑-3-硫代-2′-丙酸乙酯类Schiff碱，其结构经^1H NMR，IR，MS和元素分析表征。     

Cobalt carbonyl catalyzed reactions of disulfides: Carbonylation to thioesters and desulfurization to sulfides

aromatic and benzylic disulfides react with carbon monoxide and a catalytic amount of cobalt carbonyl to give thioesters and carbonyl sulfide, while the presence of t-butyl peroxide results in the formation of sulfides in high yields.     

Reversed steric order of reactivity for tert-butyl and adamantyl-3-cyanomethylene-1,2,4-triazines

Reactions of 2-(6-tert-butyl-5-oxo-4,5-dihydro-1,2,4-triazin-3(2H)-ylidene)-3-oxo-3-R-propanenitriles (R = t-Bu, Ad-1) with tert-butyl bromoacetate gave the corresponding N(2), C(5)O bis-alkylation products. Treatment of the latter with t-BuLi, in the case of R = t-Bu, led to intramolecular condensation at the exocyclic nitrile group. However, in the case of R = Ad-1, the condensation with the sterically more hindered carbonyl group was observed to give diastereomerically pure 8-cyanopyrrolo[1,2-b][1,2,4]triazine-6-carboxylate derivatives. The structures of the isolated products were confirmed by spectral methods and X-ray single-crystal diffraction.     

Asymmetric synthesis of differentially protected α-alkyl succinates

The alkylation of the chiral iron acyls [(η⁵-C₅H₅)Fe(CO)(PPh₃)COCH₂R] (R = H, Me, n-Pr, n-Bu, i-Bu, n-C₅H₁₁) with t-butyl bromoacetate takes place highly stereoselectively to provide a series of novel iron succinoyl complexes, which on oxidative decomplexation lead directly to chiral α-alkyl succinates.     

REACTIONS OF β-KETO SULFOXIDES WITH SULFUR ELECTROPHILES. PART II. STEREOCHEMICAL AND CONFIGURATIONAL STUDIES OF THE INTERMEDIATE ENOLATES

Abstract

Some β-keto sulfoxides containing different groups at the sulfinyl moiety were submitted to sulfenylation reaction employing two procedures: in homogeneous media and by PTC to give the corresponding monosulfenylated products. The Z configuration for the enolates of the β-keto sulfoxides independently of the group at the sulfur moiety is proved by ¹H NMR NOE difference experiments. The diastereoselectivity observed in the case of a t-butyl sulfinyl derivative is rationalized by preferred attack of the sulfur electrophile to the unhindered face of enolate not shielded by t-butyl group, as shown by X-ray analysis of the corresponding enol ether.     

Nojirimycin Based 2,5-Diketopiperazines

2,5-Diketopiperazines were prepared and characterized where one of the amino acids is (2S,3R,4R,5S)-3,4,5-trihydroxypipecolic acid. The protected pipecolic acid was synthesized from a selectively protected deoxynojirimycin derivative. The ring closure to give the diketopiperazines, from the dipeptides, was performed by nucleophilic attack of the amino function of the pipecolic acid moiety onto the carbonyl group of the methyl esters.     

Synthesis and reactions of allenic amides : Allenes-XXXI

Allenic amides are prepared from allenic nitriles using alkaline hydrogen peroxide and by a Ritter reaction with t-butyl alcohol, when N-t-butylamides are obtained. Strong nucleophiles attack the central carbon of the allene system to give α,β-unsaturated addition products.     

Metal to ligand group transfer reactions : II. Reactions of some π-allylrhodium(I) complexes with trifluoroacetic acid and alkyl,acyl and trimethyltin halides

Rh(π-C₃H₅)(PF₃)₃ (I), reacts with trifluoroacetic acid to form propene and [Rh(CF₃COO)(PF₃)₂]₂ (II). I reacts with t-butyl bromide to give [RhBr(PF₃)₂]₂ and a mixture of propene and 2-methyl-1-propene and with n-propyl bromide to give propene and [RhBr(PF₃)₂]₂. Rh(π-C₃H₅)(PPh₃)₂ (III), and t-butyl bromide yield propene and 2-methyl-1-propene. In these reactions a mechanism involving β-hydrogen abstraction and hydrogen migration via the metal to carbon is proposed. When III reacts with Me₃SnCl the Me₃Sn—moiety migrates intact to the π-allyl group. I reacts with acetyl chloride to give propene, [RhCl(PF₃)₂]₂ and the carbonyl rhodium complex Rh₂Cl₂(PF₃)₃(CO). II does not apparently undergo phosphine ligand exchange unlike the analogous halogeno-bridged dimers.     

一类高喜树碱化合物的新型合成方法

本文以溴乙酸叔丁酯与9-羟基喜树碱反应,引入了羧酸官能团,能很方便地合成一系列高喜树碱酰胺化合物。本路线摈弃了磷酸酯等保护基团,路线简洁,收率提高,羧酸官能团起到了提高喜树碱溶解度的作用,便于后面反应的进行和产物纯化。     

Lewis acid-catalyzed [4 + 3] cycloaddition of 2-(trimethyl silyloxy)acrolein with furan. Insight on the nature of the mechanism from a DFT analysis

[reaction: see text]. The mechanism for the Lewis acid-catalyzed [4 + 3] cycloaddition of 2-(trimethylsilyloxy)acrolein 1 with furan 2 has been studied at the B3LYP/6-31G level. This reaction is a three-step process that is initialized by the nucleophilic attack of 2 to the beta-conjugated position of 1 to give a zwitterionic intermediate IN1. The key step on the formation of the seven-membered ring is the electrophilic attack of the furan residue to the electrophilically activated carbonyl carbon at this intermediate.     

The conformation of 4-phenylcyclohexanone in solution by 1H- and 13C-Lanthanide induced shift (L.I.S.) analysis : Evidence in favour of phenyl over t-butyl as a conformational lock

The degree of pucker of the cyclohexanone ring in 4-phenylcyclohexanone has been refined by L.I.S. analysis. The results indicate puckering intermediate between that in cyclohexanone and 4-t-butylcyclohexanone, suggesting that phenyl may be preferable to t-butyl as a locking group in conformational analysis. The Yb (fod)3 shift reagent, although binding primarily at the carbonyl oxygen atom, also complexes weakly with the phenyl group.