三氟甲基烯烃的选择性C—F键活化最新进展（英文）

三氟甲基的选择性碳氟键活化是获得偕二氟类化合物的重要途径.鉴于三氟甲基烯烃在合成上的重要性以及反应选择性的多样性,近年来利用这类化合物的选择性碳氟键活化引起了极大的关注.综述了这一领域的研究进展,主要包括亲核加成/脱氟反应(S_N2’类型)、酸促进的脱氟傅克芳基化反应、(形式)原位脱氟官能团化反应以及过渡金属催化的迁移插入/脱氟反应.     

经由三氟甲基自由基的三氟甲基化反应研究进展

含有三氟甲基的有机分子在功能材料、农业化学品、制药等领域具有广泛应用,发展三氟甲基化的新方法是有机化学中的热点．通过产生三氟甲基自由基形成碳碳键是三氟甲基化的重要策略．本文依据三氟甲基自由基产生的不同方式,分3部分介绍三氟甲基自由基经由的碳碳键形成反应．     

过渡金属催化的芳香化合物三氟甲基化研究进展

向芳香化合物分子中引入三氟甲基在制药,农用化学品和有机材料的砌块合成中有重大的意义.由于过渡金属催化的反应反应条件温和,底物适用性广等优点,最近几年,逐渐被科学家应用到芳香化合物的三氟甲基化中,成为追捧的热点.综述了近几年在利用过渡金属对芳香化合物进行的三氟甲基化中取得的重大进展.     

氟咯草酮的合成工艺改进

以间三氟甲基苯胺为原料,与二氯乙酰氯反应制得N-间三氟甲基二氯乙酰胺(2);在碱性条件和相转移催化剂催化下化合物2与烯丙基氯发生反应得N-烯丙基-N-间三氟甲基二氯乙酰胺(3);化合物3在含金属-配体络合物催化下经分子内环化反应合成氟咯草酮(1)。经过工艺优化,本路线以78%收率得到纯度96.3%的化合物1,其结构经~1H NMR,~(13)C NMR和HR-MS(ESI)确证。     

三氟甲基芳基硫醚的合成

三氟甲基芳基硫醚由于具有高疏水性和亲脂性,在医药、农用化学品及材料科学中有着重要的应用。合成含三氟甲硫基的芳香化合物已成为有机氟化学领域的研究热点之一。本文从间接法和直接法两方面综述了向分子中引入三氟甲硫基的相关研究,包括新的三氟甲硫基化试剂以及新的合成方法在制备三氟甲基芳基硫醚中的应用,最后讨论了这些方法存在的问题,并为探索新型的、更加经济的三氟甲硫基化反应提供参考。     

三氟甲基芳基锍盐在Cu粉引发下对杂环化合物的三氟甲基化

三氟甲基芳基锍盐是一类非常温和的亲电氟烷基化试剂,已有几十年的研究历史,但是它们所有的应用几乎都局限于亲电三氟甲基化反应;含三氟甲基的芳香杂环化合物大多具有很好的药理活性,然而它们只有极少数能够用     

过渡金属催化芳香化合物三氟甲基化反应

近年来,过渡金属催化芳香化合物三氟甲基化反应迅速发展,底物适用范围不断扩展,新方法、新型三氟甲基化试剂的应用也不断涌现。本文综述了近年来过渡金属催化芳香化合物三氟甲基化的最新研究进展,包括卤代芳香化合物的三氟甲基化,芳香硼酸的三氟甲基化和芳烃C—H活化三氟甲基化反应。此外,对过渡金属催化三氟甲基化反应中涉及的机理也进行了详细地讨论。     

历经不同高价芳基铜中间体的芳香碳氢键三氟甲基化反应

在温和的铜盐促进反应条件下,四氮杂杯[1]芳烃[3]吡啶化合物发生高效、高选择性芳香碳氢键三氟甲基化反应,高产率地生成了一系列三氟甲基官能化的大环分子.基于结构明确的芳基二价铜和芳基三价铜的三氟甲基化反应的结果,铜促进的芳香碳氢键三氟甲基化反应依据三氟甲基化试剂的性质经历了两条完全不同的途径.当使用亲核性的Ruppert-Prakash试剂时,芳基三价铜与三氟甲基阴离子生成[ArCu(Ⅲ)CF₃]⁺配合物及发生还原消除是反应的关键步,而当使用亲电性的Umemoto试剂时,反应经历了芳基二价铜与三氟甲基自由基的直接偶联过程.     

从三氟甲基化反应的近年进展看有机氟化学的发展趋势

由于含三氟甲基的化合物在医药、农药等领域得到广泛应用,发展向有机分子引入三氟甲基的方法成为当前的热点研究课题.分别总结了国外和我国学者近年(主要是2009～2011年)在三氟甲基化反应研究领域取得的研究成果.从近年三氟甲基化反应的研究进展,作者提出一些值得关注的有机氟化学发展方向.     

碳-氟键断裂用于构建氟代异噁唑化合物

含氟异噁唑骨架是许多药物及农药分子中的重要结构单元,其中单氟代异噁唑类化合物的合成方法还比较有限.从易得的α-三氟甲基-β-羰基酯出发,发展了基于碱促进的碳氟键断裂策略的氟代异噁唑化合物合成方法,该反应条件温和,操作简便,官能团兼容性良好,可以中等到较好的收率得到一系列3-氟代异噁唑化合物,且所得产物可进一步转化为生物活性分子的类似物.     

C?H···N and C?H···O intramolecular hydrogen bonding effects in the 1H, 13C and 15 N NMR spectra of the configurational isomers of 1‐vinylpyrrole‐2‐carbaldehyde oxime substantiated by DFT calculations

According to the ¹H, ¹³C and ¹⁵N NMR spectroscopic data and DFT calculations, the E‐isomer of 1‐vinylpyrrole‐2‐carbaldehyde adopts preferable conformation with the anti‐orientation of the vinyl group relative to the carbaldehyde oxime group and with the syn‐arrangement of the carbaldehyde oxime group with reference to the pyrrole ring. This conformation is stabilized by the C? H···N intramolecular hydrogen bond between the α‐hydrogen of the vinyl group and the oxime group nitrogen, which causes a pronounced high‐frequency shift of the α‐hydrogen signal in ¹H NMR (～0.5 ppm) and an increase in the corresponding one‐bond ¹³C–¹H coupling constant (ca 4 Hz). In the Z‐isomer, the carbaldehyde oxime group turns to the anti‐position with respect to the pyrrole ring. The C? H···O intramolecular hydrogen bond between the H‐3 hydrogen of the pyrrole ring and the oxime group oxygen is realized in this case. Due to such hydrogen bonding, the H‐3 hydrogen resonance is shifted to a higher frequency by about 1 ppm and the one‐bond ¹³C–¹H coupling constant for this proton increases by ～5 Hz. Copyright © 2008 John Wiley & Sons, Ltd.     

GIAO,DFT, AIM and NBO analysis of the N?H···O intramolecular hydrogen‐bond influence on the 1J(N,H) coupling constant in push–pull diaminoenones

In the series of diaminoenones, large high‐frequency shifts of the ¹H NMR of the N? H group in the cis‐position relative to the carbonyl group suggests strong N? H···O intramolecular hydrogen bonding comprising a six‐membered chelate ring. The N? H···O hydrogen bond causes an increase of the ¹J(N,H) coupling constant by 2–4 Hz and high‐frequency shift of the ¹⁵N signal by 9–10 ppm despite of the lengthening of the relevant N? H bond. These experimental trends are substantiated by gauge‐independent atomic orbital and density functional theory calculations of the shielding and coupling constants in the 3,3‐bis(isopropylamino)‐1‐(aryl)prop‐2‐en‐1‐one (12) for conformations with the Z‐ and E‐orientations of the carbonyl group relative to the N? H group. The effects of the N? H···O hydrogen‐bond on the NMR parameters are analyzed with the atoms‐in‐molecules (AIM) and natural bond orbital (NBO) methods. The AIM method indicates a weakening of the N? H···O hydrogen bond as compared with that of 1,1‐di(pyrrol‐2‐yl)‐2‐formylethene (13) where N? H···O hydrogen bridge establishes a seven‐membered chelate ring, and the corresponding ¹J(N,H) coupling constant decreases. The NBO method reveals that the LP(O) →σ*_{N? H} hyperconjugative interaction is weakened on going from the six‐membered chelate ring to the seven‐membered one due to a more bent hydrogen bond in the former case. A dominating effect of the N? H bond rehybridization, owing to an electrostatic term in the hydrogen bonding, seems to provide an increase of the ¹J(N,H) value as a consequence of the N? H···O hydrogen bonding in the studied diaminoenones. Copyright © 2010 John Wiley & Sons, Ltd.     

Preparation and Intramolecular CC Coupling Reaction for Bis‐benzimidazolium Salt

Bis‐benzimidazolium salt 1 was prepared via a series of reactions using 2,2′‐diphenol as starting material. Compound 2 was afforded through the intramolecular C? C coupling reaction of 1 under the catalysis of Pd(OAc)₂. The structure of 2 is characterized through X‐ray diffraction analyses, ¹H NMR and ¹³C NMR. In 2 , two boat‐like seven‐membered rings are contained, where the C? C bond distance newly formed is 1.461(5) Å, and it is between regular C? C single bond (1.54 Å) and C?C double bond (1.34 Å). This shows that new C? C bond has partial double‐bond character. In the crystal packing of 2 , the 2D supramolecular layers are formed via C? H···F hydrogen bond.     

Weak Interactions Involving Fluorine in Suppramolecular Assemblies of Cu(Ⅱ)Complexes

Syntheses and X‐ray structural characterizations of two new Cu(II) complexes Cu(tfbz)₂(Htfbz)₂(phen) ( 1 ) (Htfbz=2,4,5‐trifluorobenzoic acid, phen=1,10‐phenanthroline) and [Cu(pfbz)₂(phen)]₂(Hpfbz)₂ ( 2 ) (Hpfbz=pentafluorobenzoic acid) are reported. The first complex crystallizes in the monoclinic space group C2/c with the crystal cell parameters a=1.9903(4) nm, b=1.3688(3) nm, c=1.3623(3) nm, β=97.90(3)°, V=3.6762(13) nm³ and Z=4. The second complex crystallizes in the triclinic space group P‐1 with the crystal cell parameters a=1.7965(4) Å, b=1.9236(2) Å, c=2.0916(2) Å, α=110.156(2) °, β=105.040(3) °, γ=98.123(3) °, V=6.3372(17) nm³ and Z=4. The crystallographic analyses revealed that F···H–C hydrogen bonds in both complexes lead to formation of infinite three‐dimensional supramolecular networks. A large number of F···F interactions in complex 2 ensure the stability of intricate crystal structure.     

Assessment of intermolecular interactions at three sites of the arylalkyne in phenylacetylene‐containing lithium‐bonded complexes: Ab initio and QTAIM studies

The intermolecular interactions existing at three different sites between phenylacetylene and LiX (X = OH, NH₂, F, Cl, Br, CN, NC) have been investigated by means of second‐order Møller?Plesset perturbation theory (MP2) calculations and quantum theory of “atoms in molecules” (QTAIM) studies. At each site, the lithium‐bonding interactions with electron‐withdrawing groups (? F, ? Cl, ? Br, ? CN, ? NC) were found to be stronger than those with electron‐donating groups (? OH and ? NH₂). Molecular graphs of C₆H₅C?CH···LiF and πC₆H₅C?CH···LiF show the same connectional positions, and the electron densities at the lithium bond critical points (BCPs) of the πC₆H₅C?CH···LiF complexes are distinctly higher than those of the σC₆H₅C?CH···LiF complexes, indicating that the intermolecular interactions in the C₆H₅C?CH···LiX complexes can be mainly attributed to the π‐type interaction. QTAIM studies have shown that these lithium‐bond interactions display the characteristics of “closed‐shell” noncovalent interactions, and the molecular formation density difference indicates that electron transfer plays an important role in the formation of the lithium bond. For each site, linear relationships have been found between the topological properties at the BCP (the electron density ρ_b, its Laplacian ?²ρ_b, and the eigenvalue λ₃ of the Hessian matrix) and the lithium bond length d(Li‐bond). The shorter the lithium bond length d(Li‐bond), the larger ρ_b, and the stronger the π···Li bond. The shorter d(Li‐bond), the larger ?²ρ_b, and the greater the electrostatic character of the π···Li bond. © 2012 Wiley Periodicals, Inc.     

Synthesis,Structure, and Solution Study of a Mercury(II) Complex with the Ligand [1‐(2‐Methoxyphenyl)‐3‐(4‐chlorophenyl)]triazene

The title ligand, [1‐(2‐methoxyphenyl)‐3‐(4‐chlorophenyl)]triazene, H L ( 1 ), was prepared. In a reaction with Hg(NO₃)₂ it forms the complex [Hg(C₂₆H₂₂Cl₂N₆O₂)], [Hg L ₂] ( 2 ). Both compounds were characterized by means of X‐ray crystallography, CHN analysis, FT‐IR, ¹H NMR, and ¹³C NMR spectroscopy. In the structure of compound 1 , two independent fragments are present in the unit cell. They exhibit trans arrangement about the –N=N– double bond. The dihedral angles between two benzene rings in both fragments are 4.36 and 18.79 Å, respectively. Non‐classic C–H ··· N hydrogen bonding and C–H ··· π interactions form a layer structure along the crystallographic ab plane [110]. In compound 2 , the Hg^II atom is hexacoordinated by two tridentate [1‐(2‐methoxyphenyl)‐3‐(4‐chlorophenyl)]triazenide ligands through a N₂O₂ set. In addition, in the structure of 2 , monomeric complexes are connected to each other by C–H ··· π stacking interactions, resulting in a 2D architecture. These C–H ··· π edge‐to‐face interactions are present with H ··· π distances of 3.156 and 3.027 Å. The results of studies of the stoichiometry and formation of complex 2 in methanol solution were found to support its solid state stoichiometry.     

Pentafluorobenzoato‐dimolybdenum(II) Solvate and Co‐crystal Complexes with Benzene and Naphthalin

The quadruply bonded Mo₂⁴⁺ complex Mo₂(DAniF)₃(OOCC₆F₅) ( 1 ) [DAniF = N,N′‐bis(4‐methoxyphenyl)formamidinate] was synthesized. The solvate Mo₂(DAniF)₃(OOCC₆F₅) · (C₆H₆) ( 2 ) and co‐crystal Mo₂(DAniF)₃(OOCC₆F₅) · (C₁₀H₈) ( 3 ) complexes were obtained by self‐assembly of crystals of 1 with benzene and naphthalin, respectively. Compounds 1 , 2 , and 3 were structurally characterized by single‐crystal X‐ray diffraction. In monomer 1 , the Mo–Mo bond length of 2.0874(6) Å is typical for dimolybdenum quadruple bonds. The solvate complex 2 was stabilized by weak π–π stacking interactions between the benzene molecule and the pentafluorophenyl ring (as indicated by a center‐to‐center distance of 3.838(10) Å and a center‐to‐plane distance of 3.712(4) Å between phenyl and pentafluorophenyl ring) and intermolecular C–H ··· F–C interactions (the shortest F ··· H distance is 2.560(2) Å). In complex 3 , a one‐dimensional chain was formed by C–H ··· F–C interactions between the hydrogen atoms in naphthalin and the fluorine atoms in the monomer (H ··· F distances of 2.582(2) Å). Information on the structures in solution of the three crystals was obtained by ¹H NMR spectroscopy.     

基于2,4′-二羧基二苯甲酮构筑的具有一维梯状链和一维隧道的三维超分子体系

采用水热法设计合成了两个新型三维超分子化合物H₂L·H₂O (1)和[Ag(bpy)₂]·HL·H₂O (2) (其中bpy=2,2'-联吡啶, H₂L=2,4′-二羧基二苯甲酮),晶体结构分析表明,它们均是通过氢键采用不同的连接方式拓展而成。其中,化合物1 是2,4′-二羧基二苯甲酮和水分子通过O–H···O氢键形成的一维梯状链扩展构筑的三维超分子体系;化合物2 则是2,4′-二羧基二苯甲酮和水分子通过两种氢键形成含有一维隧道的三维超分子体系。有趣的是,[Ag(bpy)₂]⁺ 阳离子通过π–π 堆积和弱的Ag···Ag相互作用连在一起,进而以客体形式填充其中。荧光性质研究表明,由于存在bpy的螯合与堆积效应,化合物2相比配体和化合物1,其荧光发射峰发生红移。     

Crystallographic report: 1,4‐Bis[(phenyldichlorostannyl)ethyl]benzene,p‐(Cl2PhSnCH2CH2)2C6H4

An ‘S’ conformation, stabilized by intramolecular C? H···π interactions, is found in centrosymmetric p‐(Cl₂PhSnCH₂CH₂)₂C₆H₄. The dinuclear species features distorted tetrahedral tin centres, with the greatest distortion manifested in the C? Sn? C angle of 134.32(16) °. Copyright © 2002 John Wiley & Sons, Ltd.     

Crystallographic report: 1,4‐Bis(triphenylstannylmethyldimethylsilyl)benzene,p‐(Ph3SnCH2SiMe2)2C6H4

The dinuclear molecule of p‐(Ph₃SnCH₂SiMe₂)₂C₆H₄ adopts an ‘S’ conformation in the solid state, which is stabilized by C? H···π interactions. Distorted tetrahedra defined by C₄ donor sets are found for the tin atoms. Copyright © 2002 John Wiley & Sons, Ltd.