茚磺苯酰胺及其合成中间体的NMR研究

合成了茚磺苯酰胺(Ⅰ),测试了它的¹HNMR谱以及合成中间体(Ⅱ-Ⅶ)的¹H和¹³CNMR谱,常温下观测到了化合物(Ⅲ)的旋转异构现象,讨论了ABX自旋系统中,解析质子化学位移的另一种方法。     

氟烯的结构-特性关系 Ⅱ.某些含氟烷基取代环丙烷的核磁共振谱及质谱

本文报导了十七个新的含氟烷基单取代环丙烷的核磁共振谱及质谱数据,着重讨论了含氟烷基对环上质子的屏蔽效应.烷基取代基中α碳(与环直接相联的碳)上的氢为氟原子取代之后,不仅使所有环上质子的化学位移向低场移动,并且使环上之顺式质子与反式质子的化学位移差Δδ减小,对应于三种类型的环丙烷:和相应的Δδ值分别为～0. 4、～0. 2和<0. 1ppm.这说明除了与环直接相联的 C-C 键外,与α碳相联的键(如 C-F 键)对环上质子的化学位移也有重大影响.文中对质谱也作了简单的讨论.     

1-苯基-3-(3'-吲哚基)-5-取代苯基-2-吡唑啉的合成及1H NMR和MS中的取代基效应

J-(3'-吲哚基)-3-取代苯基-2-丙烯-1-酮与茉肼反应,合成了10种新的1-苯基-3-(3'-吲哚基)-5-取代苯基-2-吡唑啉衍生物,其结构通过各种波谱证实.讨论了此系列化合物¹HNMR和Ms中的取代基效应,得出取代基常数σ或σ⁺与质子化学位移,碎片相对丰度之间存在着良好的线性关系.     

稠环芳烃系列化合物化学位移的计算——Ⅲ.稠环芳烃13C化学位移的加合性

本文在稠环芳烃质子化学位移及甲基稠环芳烃甲基质子化学位移加合性的基础上考虑到稠环芳烃分子中碳原子微环境的特点、π电子环流以及碳原子受到的范德华作用对¹³C化学位移的贡献机理,提出12种类型的六元碳环结构因素,并利用10个化合物的80个¹³C化学位移实验数据得出适合于稠环芳烃¹³C化学位移的普遍公式,按这一公式计算结果的标准误差为lppm,远小于现有的半经验量子力学方法的计算误差.说明稠环芳烃系列分子的¹³C化学位移也存在加合性规律.利用本计算方法可较准确地鉴别和预示已合成的稠环芳烃分子的¹³C化学位移值.本文计算了55个稠环芳烃分子的674个非等性的¹³C化学位移.     

双环戊二烯基二(芳氧基)钛、锆、铪衍生物的13C核磁共振谱

第Ⅳ副族金属的双环戊二烯基二卤化物及取代双环戊:二烯基二卤化物的¹³C NMR谱已有一些报道.但关于双环戊二烯基二(芳氧基)钛、锫、铪类型化合物的¹³C NMR谱则尚未见系统报道.我们研究其¹³C NMR谱,目的在于探讨第Ⅳ副族的不同金属以及芳环对位不同取代基对¹³C化学位移的影响.我们发现环戊二烯环的¹³C化学位移随金属周期数的增加而有规律地移向高场.同时,在钛、锆、铪三个系列的化合物中,不论是芳环还是环戊二烯环,其相应碳原子的¹³C化学位移之间存在着非常好的线性关系,相关系数等于或优于0.99.     

钨钼杂多酸及其盐与二甲基甲酰胺加合物的制备和性质研究

合成了10种钨钼杂多酸及其盐与DMF的加合物,用IR光谱、Raman光谱、UV光谱、¹HNMR、TG-DTA和X射线衍射方法研究了加合物的性质。加合物中配体DMF以C=O键的氧作为配位原子,与杂多酸中的质子或杂多酸盐中的金属阳离子配合成键。IR光谱中ν_c-o的位移可作为配位键成键强度的判据。     

二苯并碘国正离子的π电子结构

碘杂环化合物最近引起了化学工作者的注意。二苯并碘国正离子(diphenyleneiodoniumcation)溴盐及碘盐的制备早在本世纪初已经成功。1956年Collete等提出合成5,6,7或8员二苯并碘杂环的方法。近年来,黄文魁,高振衡等亦制备了一系列碘杂环化合物。 Irving等根据电子光谱(见图1)指出,二笨并碘国正离子与芴的结构相似。芴为平面型结构,已经用不同方法得到证实。可以认为二苯并碘国正离子也具有平面或近平面结构。     

混合三烃基锡衍生物的研究(Ⅱ)─一丁基二环己基锡羧酸酯的合成、结构表征及生物活性

合成了21个混合三烃基锡羧酸酯。利用红外光谱、核磁共振谱(¹H,¹³C,¹¹⁹Sn)和质谱表征了化合物的结构。对取代苯甲酸酯化合物,锡原子的化学位移δ(¹¹⁹Sn)与苯环上取代基的Hammett常数有很好的线性关系。化合物的生物活性测定结果表明,它们具有高效杀螨活性。     

核磁共振INDOR法研究若干单糖分子的构型和构象

本文用核磁共振谱的INDOR,研究若干单糖在DMSO溶液中的构型和构象。在单糖分子中,除少数质子如差向异构氢(C₁—H)外,大多数质子处于相似的化学环境中,相邻者又彼此偶合,在常规核磁共振谱上产生的信号重迭交错,形成峰包,无法一一辨认以确定归属。从木糖、阿拉伯糖、甘露糖、鼠李糖等单糖在DMSO中的1NDOR谱,可间接测得C₂～C₄上质子的各组谱线,进而获得每一质子的化学位移及偶合常数。用Karplus方程定出相邻碳上质子的两面角及C—H键取向,因而确证这些分子在DMSO中的立体结构。     

手性螺-环丙烷类化合物的结构特征和解析

通过IR,¹HNMR,¹³CNMR,UV,MS以及X射线晶体衍射测定方法来确认一类新的手性螺-环丙烷化合物的化学结构.为研究新的螺环/环丙烷类复杂化合物的结构提供了有价值的依据.     

Atroposelective Ring Opening of Cyclic Diaryliodonium Salts with Bulky Anilines Controlled by a Chiral Cobalt(III) Anion

The present work demonstrates a CuCl and anionic chiral cobalt(III)-catalyzed enantioselective ring-opening reaction. The small-size, ligand-free copper species enabled the cross-coupling of iodonium salts with a series of bulky aromatic amines in high ee values. The chiral cobalt(III) anion causes appreciable chemical shift changes of cyclic diaryliodoniums in ¹H NMR spectra.     

Charge transfer complexes as dual thermal/photo initiators for free-radical frontal polymerization

Frontal polymerization is a process in which a localized reaction zone propagates from the coupling of thermal transport and the Arrhenius rate dependence of an exothermic polymerization; monomer is converted into polymer as the front passes through an unstirred medium. Herein we report the first study of charge transfer complexes (CTCs) as photo/thermal initiators for free-radical frontal polymerization. Front velocity was studied as a function of mole ratio between an aromatic amine, such as dimethyl-p-toluidine or dimethylaniline, and an iodonium salt. It was found that the front velocity reached a maximum at a certain mole ratio of amine to iodonium salt. The velocity remained constant upon increasing the ratio of amine to iodonium salt past this critical ratio. Fronts were also studied using N-phenyl glycine as an electron donor, but its utility was limited by low solubility. Lastly, the steric and electronic effects of the iodonium salt and counter anion were explored. It was found that CTCs using iodonium salts with less nucleophilic anions gave higher front velocities. In terms of intrinsic reactivity, the CTC composed of N,N-dimethyl-p-toluidine and bis[4-(tert-butyl)phenyl]iodonium tetra(nonafluoro-tert-butoxy)aluminate gave the highest front velocity per molal of iodonium salt.     

Kinetics and reaction mechanisms of diazo compounds and iodonium salts as studied by chemically induced dynamic nuclear polarisation

CIDNP phenomena in various reactions of diazo compounds and iodonium salts are described. The various reaction pathways leading to the formation of polarised aromatic products are analysed in detail.     

Fast atom bombardment mass spectra of iodonium salts

Positive-ion fast atom bombardment mass spectra and linked-scan tandem mass spectra were measured for aromatic iodonium salts. The mass spectra usually contain the intact cation of the iodonium salt as the base peak, fragment ions of lower abundance resulting from simple cleavages or rearrangements, and a characteristic loss of atomic iodine. High-level semi-empirical calculations suggest that an obtuse ring? I⁺? ring angle facilitates loss of atomic iodine through concomitant ring? to? ring bond formation.     

Photosolvolysis of (E)-styryl(phenyl)iodonium tetrafluoroborate. Generation and reactivity of a primary vinyl Cation

The photochemistry of (E)-styryl(phenyl)iodonium tetrafluoroborate in methanol and 2,2,2-trifluoroethanol as well as in dichloromethane and toluene has been investigated. In all solvents the vinylic C [bond] I bond is more photoreactive than the aromatic C [bond] I bond. Homolysis as well as heterolysis of both bonds occurs, but the latter type of cleavage predominates. In alcoholic solvents, the incipient phenyl cation produces a nucleophilic substitution product. The primary styryl cation gives nucleophilic substitution, elimination, and rearrangement products. The dependence of the photoreaction on the nucleophilicity of the solvent indicates that in the presence of good nucleophiles a 10-I-3 compound is the reactive iodonium species. In this case the reaction proceeds via an S(N)i mechanism. In the absence of good nucleophiles an 8-I-2 species gives photoreaction via an S(N)1 mechanism. This is corroborated by the solvent dependence of the UV spectra, and the product composition upon photoreaction with bromide in varying concentration. Photoreaction of the iodonium salt in a chlorinated alkane yields (E)- and (Z)-beta-fluorostyrene in a Schiemann-type reaction. Reaction in toluene yields Friedel-Crafts products. The results of the photochemical reactions are compared to those of the thermal ones, and the implications of the differences are discussed.     

The Pd-catalyzed synthesis of difluoroethyl and difluorovinyl compounds with a chlorodifluoroethyl iodonium salt (CDFI)

Herein, we report a simple and efficient method for the direct installation of chlorodifluoroethyl group onto aromatic molecules of various aromatic amides with a new 2-chloro,2,2-difluoroethyl(mesityl)iodonium salt (CDFI). Moreover, the chlorodifluoroethyl compounds could be smoothly converted into difluorovinyl compounds in a one-pot or discrete procedure and regarded as a steady source of difluorovinyl compounds with “HCl-mask”.     

Synthesis and characterization of photosensitive polyimides

All aromatic polyimides bearing diarylsulfide linkages in the main chain were prepared either by condensation of a sulfur containing dianhydride with an aromatic diamine or the condensation of a sulfur containing aromatic diamine with a dianhydride. Phenylation with diphenyl iodonium salts was then used to convert the diarylsulfide groups to triarylsulfonium salts. The resulting photosensitive polyimides were shown to undergo main chain cleavage during photolysis using UV irradiation. These new polyimides are candidates for positive working, high temperature photoresist materials.     

Synthesis and Reactivity of (β-Amino-α-acylalkenyl)phenyliodonium Salts

During the last few years alkenyl(phenyl)iodonium salts have risen from mere chemical curiosities to valuable synthetic intermediates. [1] Because of an excellent leaving group ability of a phenyliodonyl moiety, alkenyl(phenyl) iodonium salts undergo nucleophilic vinyl substitutions under mild conditions, thus providing a useful route for the synthesis of various kinds of olefins. Recently, some of functionalized alkenyl iodonium salts have been prepared. [2]     

Nitroylides

Conclusions On interacting iodonium dinitromethylides with aromatic hydrocarbons of the benzene series the corresponding aryldinitromethanes were formed, i.e., the product of introducing the carbanion portion of the ylide at the C-H bond of the aromatic ring. The influence of temperature and added salts of transition metals on the yileld of reaction products has been clarified.Translated from Izvestiya Akademii Nauk SSSR, No. 12, pp. 2741–2746, December, 1982.     

Iron(II)‐Catalyzed Direct Cyanation of Arenes with Aryl(cyano)iodonium Triflates

A direct oxidative cyanation of arenes under Fe^II catalysis with 3,5‐di(trifluoromethyl)phenyl(cyano)iodonium triflate (DFCT) as the cyanating agent has been developed. The reaction is applicable to wide range of aromatic substrates, including polycyclic structures and heteroaromatic compounds.