羟基蒽醌衍生物中羟基质子的核磁共振研究

通过对23个羟基蒽醌衍生物的质子核磁共振研究, 观察了不同取代类型羟基的化学位移范围;讨论了酚羟基乙酰化对芳环质子的化学位移影响, 为羟基取代位置的确定及芳环质子谱线归属提供了某种判据.此外, 还用HMO 法探讨了各类取代羟基的氢键强度及羰基迫位仅有一个羟基的内氢键强度与给予原子电荷密度的关系.本文报道一系列新型冠醚N,N'-双取代-1,7-二氧杂-12-冠-4(1~6), N,N' -双取代-1, 7-二氮杂-15冠-5(7~10) 及N,N'-双取代-1,10-二氮杂-18-冠-6(11~14)的质谱. 借助联动扫描和去焦技术对它们的开裂机理作了详细探讨.     

取代杂氮硅三环的核磁共振及分子动力学研究

对取代的杂氮硅三环类化合物(Silatrane)-(3R,4S)-1-氯甲基杂氮硅三环-4-羧酸(1)和(3R,4S)-1-氯甲基-3-甲基杂氮硅三环-4-羧酸(2)及它们相应的三乙基铵盐(3)和(4)的结构采用^1H,^1^3C,^2^9Si NMR进行研究, 其一维^1H NMR谱根据二维同核和异核相关谱进行了归属。从测得的偶合常数及化学位移分析, 得出羧基及其铵盐的取代造成相邻另外两环上的-CH2-CH2-O-链上二面角发生扭拐,成为拐折旁式构象。分子动力学方法的模拟计算证明了这种构象变化。另外根据溶液中^2^9Si及^1H的化学位移实验结果, 讨论了该类化合物环上取代对分子内配键(N-Si)的影响。     

混合三烃基锡衍生物的研究VIII: 甲基二环己基锡(取代)苯氧乙酸酯的合成、结构表征和生物活性

本文合成了二十个混合甲基二环己基锡取代苯氧乙酸酯。研究了这些化合物的IR, NMR (^1H, ^1^3C, ^1^1^9Sn), 结果表明, 除邻甲氧基苯氧乙酸酯外, 这些化合物都可能是以羰基氧为桥连的五配位聚合有机锡化合物。^1^1^9Sn NMR的研究结果表明, ^1^1^9Sn化学位移与苯环上取代基有一线性关系: δ^1^1^9Sn=6.23σ+94.67, r=0.943。农药的初筛表明, 这些化合物除有很好的杀螨活性外, 还有一定的杀菌, 除草和植物激素作用。     

3,5-二甲基-DL-酪氨酸与铜(Ⅱ)和具极性侧基氨基酸配体配合物稳定性的研究

采用pH电位滴定法,研究了合成配体3,5-二甲基-DL-酪氨酸(DL-Dmtyr)与铜(Ⅱ)的二元配合物,及进一步与带正电荷或极性侧基的氨基酸配体形成三元混配配合物的稳定常数,考察了甲基对稳定性的贡献;用核磁共振研究了DL-Dmtyr与铜(Ⅱ)和L-Arg混配配合物中的配体间静电氢键作用.研究结果表明,甲基取代碘基后,混配配合物分子内的配体相互作用明显增强.     

混合三烃基锡衍生物的研究VIII: 甲基二环己基锡(取代)苯氧乙酸酯的合成、结构表征和生物活性

本文合成了二十个混合甲基二环己基锡取代苯氧乙酸酯。研究了这些化合物的IR, NMR (^1H, ^1^3C, ^1^1^9Sn), 结果表明, 除邻甲氧基苯氧乙酸酯外, 这些化合物都可能是以羰基氧为桥连的五配位聚合有机锡化合物。^1^1^9Sn NMR的研究结果表明, ^1^1^9Sn化学位移与苯环上取代基有一线性关系: δ^1^1^9Sn=6.23σ+94.67, r=0.943。农药的初筛表明, 这些化合物除有很好的杀螨活性外, 还有一定的杀菌, 除草和植物激素作用。     

3-乙酰基取代吡咯衍生物的合成及其晶体结构

本文通过Knorr合成法制备了四个3-位乙酰基取代的吡咯衍生物:1, 2-二甲基-4-异丙基-5-苯基-3-乙酰基-吡咯(5a); 1, 2, 4-三甲基-5-对甲氧苯基-3-乙酰基-吡咯(5b); 1, 2, 5-三甲基-4-苯基-3-乙酰基-吡咯(5c); 1, 2, 5-三甲基-4-对甲氧苯基-3-乙酰基-吡咯(5d)。通过红外, 质谱, 核磁等方法对其结构进行了表征。测定了其中三个化合物的晶体结构。对这类吡咯环上4或5-位有芳环取代基时化合物的晶体结构特征进行了扼要讨论, 晶体衍射实验结果表明,4, 5-位上的芳环与吡咯环本身处于非共平面结构。     

两种中位不对称四苯基卟啉的氢谱解析

剖析两种结构不对称氰基取代四苯基卟啉(5-对氰基苯基-10,15,20-三对甲基苯基卟啉(triCH3,CN-TPP)和5-对甲基苯基-10,15,20-三对氰基苯基卟啉(triCN,CH3-TPP)的核磁共振氢谱。     

三取代环丙烷的^1^3C核磁共振谱研究

前文曾报道三取代环丙烷的质子核磁共振谱及其解析结果,讨论了取代基对化学位移和偶合常数的影响.环丙烷的~(13)C核磁共振谱研究报道极少。Monti等人研究了甲基、溴代和乙炔基环丙烷的~(13)C核磁共振谱,发现在多取代的环丙烷中,取代基相互之间的影响是很显著的.Clague等人亦报道了一系列环丙烷的~(13)C核磁共振谱,但未有详细的分析.本文报道10种尚未见载于文献的三取代环丙烷的~(13)C核磁共振谱,数据见表1. 在1,2,3-三取代环丙烷中,由于取代基的相互作用,影响环上碳的化学位移的因素是比较复杂的.从我们测定化合物的数据来看,取代基为CH_3的环上碳的平均化学位移为29.24     

单重态氧化学 V: 二烷基取代酚光敏氧化反应的研究

本文研究了2,6-二甲基酚、2,4-二甲基酚及3,4-二甲基酚的光敏氧化反应, 应用竹红菌甲素作敏化剂匹配高压钠灯首次提供了二烷基取代酚同单重态氧发生化学反应的例证, 并测定了它们对单重态氧的反应速度常数, 其反应活性顺序为:BHT>2,4-DMP>3,4-DMP>DBP>2,6-DMP.二烷基取代酚同单重态氧可能通过1,4-环加成反应的机理, 再经重排生成最终产物.     

核磁共振波谱法测定液体乳中的1,2-丙二醇

采用核磁共振氢谱(~1H NMR)、选择性一维全相关谱(1D-TOCSY)及定量核磁共振法(qNMR)对液态乳中的1,2-丙二醇进行了快速筛查及含量测定,并与气相色谱法的测定结果进行了比较。~1H NMR法以液态乳基质中1,2-丙二醇的甲基质子信号特征为初步定性标准,选择性一维全相关谱法以1,2-丙二醇的亚甲基和次甲基质子信号特征为精确定性标准。在定性检测基础上,采用定量核磁共振法以1,2-丙二醇δ 1.15处的质子峰为定量峰,3-(三甲基硅基)氘代丙酸钠(TMSP)δ 0.00处的峰为内标峰,测定了液体乳中1,2-丙二醇的绝对含量。方法的检出限为0.002 mg/mL,定量下限为0.006 mg/mL。实际样品测定结果显示,NMR法与气相色谱法的检测结果一致,且NMR法前处理简单,操作方便,专属性高,在提高检测效率的同时能够避免假阳性结果出现,非常适合实际检测中液体乳中1,2-丙二醇的批量、快速检测。     

超分子体系中的分子识别研究(Ⅻ)──环糊精及环糊精双核铜配合物对4-取代苯酚的分子识别

用分光光度滴定法在25.0℃时测定了不同pH值下α-,β-,γ-环糊精以及1mol/LNaOH水溶液中α-和β-环糊精双核铜配合物与4-取代苯酚形成超分子配合物的稳定常数.化学计量法表明,主体环糊精及环糊精双核铜配合物与客体4-取代苯酚形成了1：1的超分子配合物.从主-客体间的尺寸关系、pH值、多点识别和诱导契合作用等因素讨论了环糊精及环糊精双核铜配合物对客体4-取代苯酚的分子识别机制.结果表明,β-环糊精双核铜配合物对4-取代苯酚具有特殊的键合能力和分子选择性。     

Palladium-catalyzed intermolecular coupling of 3-substituted propargylic carbonates with phenols: Synthesis of 2-substituted benzofuran derivatives

We accomplished the synthesis of 2-substituted benzofuran derivatives by the palladium-catalyzed reaction of 3-substituted propargylic carbonates with phenols. The 2-substituted benzofuran derivatives were obtained through the intermolecular coupling of the 3-substituted propargylic carbonates with phenols, and sequential intramolecular cyclization reaction.     

Efficient oxidative ipso-fluorination of para-substituted phenols using pyridinium polyhydrogen fluoride in combination with hypervalent iodine(III) reagents

Diacetoxyiodobenzene (PIDA) and bis(trifluoroacetoxy)iodobenzene (PIFA) in the presence of pyridinium polyhydrogen fluoride (PPHF) are effective for the fluorination of para-substituted phenols to give a variety of 4-fluorocyclohexa-2,5-dienones in a good yield. (R,S)-1,1′-Bi-5,6,7,8-tetrahydro-2-naphthol (and its monoacetate) yields atropoisomeric fluorocyclohexadienones. The 4-substituted carbamate open-chain phenols were readily converted to fluorohydroindolenone and fluorohydroquinolenone derivatives by intramolecular conjugate addition.     

Yb(OTf)3-catalyzed reactions of 5-alkylidene Meldrum's acids with phenols: one-pot assembly of 3,4-dihydrocoumarins, 4-chromanones, coumarins, and chromones

[reaction: see text] The Yb(OTf)3-catalyzed annulation reactions of phenols with 5-alkylidene Meldrum's acids enabled the synthesis of structurally diverse heterocycles in high isolated yields. A series of 4-substituted 3,4-dihydrocoumarins, 2,2-disubstituted 4-chromanones, coumarins, and 2-substituted chromones were readily and efficiently assembled, including the naturally occurring coumarins citropten, scoparone, and ayapin. Addition of phenols to biselectrophilic 5-alkylidene Meldrum's acids proceeded through two distinct multibond-forming modes: Friedel-Crafts C-alkylation/O-acylation and Friedel-Crafts C-acylation/O-alkylation. The regioselectivity of the catalytic annulation reaction was controlled by the degree of substitution on the alkylidene moiety.     

Synthesis of some novel heterocyclic dyes derived from pyrazole derivatives

Diazotized aryl amines were coupled with 3-substituted 5-amino pyrazoles to produce a series of novel 3-substituted 5-amino-4-arylazopyrazoles. Also, 3-substituted 5-amino-pyrazoles were diazotized and coupled with different phenols to give the corresponding novel 3-substituted 5-aryl azo pyrazoles. These dyes were characterized by elemental analysis and spectral data, applied to different types of fibres (wool, polyester and a blend of wool/polyester as disperse dyes) and their fastness properties were evaluated.     

One-Pot Generation of Benzynes from Phenols: Formation of Primary Anilines by the Deoxyamination of Phenols

Benzynes were selectively generated in situ from phenols and trapped regioselectively with potassium hexamethyldisilazide to form primary anilines following acidic workup. The direct conversion of a phenolic hydroxyl group into a free amino group is a useful method for the preparation of primary aryl amines that are hard to synthesize by using coupling reactions involving phenol derivatives with ammonia. Whereas reactions of ortho- and meta-substituted phenols produced meta-substituted anilines exclusively, those of para-substituted phenols provided ortho-silylanilines.     

A novel and convenient approach for tosyloxylation of aromatic ring of some ortho-substituted phenolic compounds using [hydroxy(tosyloxy)iodo]benzene

The oxidation of some substituted monohydric phenols, containing electron-withdrawing substituents at the ortho position to the phenolic group, with [hydroxy(tosyloxy)iodo]benzene (HTIB, Koser’s reagent) leads to novel tosyloxylation of aromatic ring, thereby offering a convenient synthesis of hitherto unknown 4-tosyloxy-2-substituted phenols.     

Ionic liquid crystalline hydrogen-bonded associates based on phenols

Different 4-substituted phenols were mixed with 1-n-heptyl-4-(4-pyridyl)pyridinium chloride. In the phase diagrams thermodynamically stable solid 1 :1 hydrogen-bonded ionic associates were detected. Smectic A phases are stabilized in mixtures between the proton donor and the associate.     

Improved procedure for the bimolecular oxidative amidation of phenols

Trifluoroacetic acid (TFA) is an effective promoter of the bimolecular Ritter-like oxidative amidation of 4-substituted phenols induced by PhI(OAc) 2 in MeCN. This suppresses the need for fluoroalcohol cosolvents, increases the yields, and facilitates isolation/purification procedures.     

2－取代氨基－4，6－二氯嘧啶类化合物的合成及其杀菌活性

以４，６－二氯嘧啶－２－异氰酸酯与胺类、肼类及醇类化合物反应，合成了１８个未见文献报道的标题化合物。它们的结构经ＩＲ、１ＨＮＭＲ证实。其中苯硫甲基磺酰脲类化合物有较好的杀菌活性。