One-Pot Convenient and High Yielding Synthesis of Dithiocarbamates

Summary. A convenient and high yielding method for the synthesis of diverse dithiocarbamates having various substituents including alkyl, aryl, heteroaryl, and alkylaryl at the thiol chain or at the amine chain or at both thiol and amine chains were developed by the one-pot reaction of mercaptans, amines, and bis(benzotriazolyl)methanethione in presence of amidine base under mild reaction conditions.     

Novel ring transformation of quinolines to indole derivatives in two steps via 1,4-dihydroquinoline derivatives

Diphenyl 1-phenoxycarbonyl-1,4-dihydroquinoline-4-phosphonates 5c-g, obtained from the reaction of corresponding quinoline derivatives 1 with phenyl chloroformate and triphenyl phosphite in one step, were ozonized in CHCl₃ and CH₃COOH. Treatment of the resulting mixture with NaHCO₃ produced the 3-formyl-1-phenoxycarbonylindole derivatives 8a-e in high yields. The ring transformation of quinolines 1 to indoles 8 proceeds under mild conditions.     

异亚硝基乙酰乙酸乙酯亚胺Pd(Ⅱ)配合物的合成、表征和tran Pd(p-CH3C6H4-IEAI)2的晶体结构

Six palladium(Ⅱ) complexes with isonitrosoethylacetoacetate imine Schiff base ligands, Pd(R-IEAI)₂, were prepared and characterized by IR, Raman and electronic spectra. Complex tran Pd(p-CH₃C₆H₄-IEAI)₂ (2) cry- stallizes in the monoclinic system, space group P2₁/c,with a=1.2002(2),b=0.9972(2),c=1.1121(2)nm,β=90.43(3)°,Z=2,F(000)=616,μ=7.44cm^-1. The final R and wR are 0.0244 and 0.0625 for 2620 ob-served reflections with I≥2σ(I), respectively. The geometry around the Pd(Ⅱ) ions in those complexes has a distorted PdN₄ square plane, the Schiff base ligands R-IEAI^- being coordinated through their oximino-nitrogen atoms and imino-nitrogen atoms.     

Synthesis and magnetic properties of poly(p‐phthaloyl‐disacetylaceton‐ethylenediimine) metal complexes

Macrocyclic Schiff‐base ligand, bisacetylaceton‐ethylenediimine (BAE) and its transition metal complexes M(BAE) (M = Cu²⁺, Ni²⁺) were synthesized. The complexes having characteristics of aromatic systems and well‐defined one‐dimensional structures, reacted with p‐phthaloyl chloride, to obtain polymer complexes. The complexes were characterized by elemental analysis, inductively coupled plasma (ICP), FT‐IR, and thermal analysis and show good thermal stability. ESR spectra analysis discovered that there are free radicals in the chain of polymers, indicating that a weak magnetic spin‐exchange interaction operates between the metal ions and free radicals. It is found that, as the bridging p‐phthaloyl group is able to propagate the magnetic exchange interaction, the polymer complexes show paramagnetic properties by measurement of temperature dependence of the magnetic property, and obey Curie–Weiss law. Copyright © 2001 John Wiley & Sons, Ltd.     

Vicarious nucleophilic substitution in enamine derivatives of 1-hydroxynaphthalene-2,4-dicarbaldehyde

The reaction of aromatic amines with highly stable Schiff base enamines formed from an alkyl amine and 1-hydroxynaphthalene-2,4-dicarbaldehyde resulted in nucleophilic substitution of the alkyl amine with the aromatic amine in ethyl alcohol at room temperature within 1-2 min. This reactivity, regioselectivity and formation of stable derivatives are due to extra stabilization through extended conjugation in these systems.     

含呋喃环Schiff碱型大环化合物的合成及其与Ba^2+,Sr^2+配合行为

利用Mn^2+，Ba^2+及Sr^2+作为模板离子，合成了一类新型的含呋喃环系 Schiff碱型大环化合物，如L^1和配合物L^2Ba(ClO4)2，L^3Ba(ClO4)2和L^4Ba (ClO4)2.L^2-L^4的Ba^2+配合物经与NaSO4水溶液反应解络，得到自由配体L^2， L^3和L^4，配体L^2和L^3分别与Sr^2+作用，得到配合物L^2Sr(ClO4)2和L^3Sr (ClO4)2。上述大环配体和各种配合物均经元素分析，IR，^1H NMR，MS等证实了它 们的结构和组成。     

Mono- and diboronates derived from tridentate ONO ligands and arylboronic acids

The syntheses of eight [4.3.0] heterobicyclic boronates containing a N → B coordinative bond are described. The monomeric compounds were prepared by reaction of arylboronic acids with a tridentate ligand having the ONO donor set of atoms. It was shown that substituents at the para-position of the B-phenyl moiety transmit electronic effects to the CN bond which in turn is polarized by formation of the N → B coordination bond. At the same time, related tridentate ligands were also reacted with 1,4-benzenediboronic acid in order to prepare benzene diboron complexes. The structure of this type of compounds was confirmed by X-ray analysis for one of the derivatives.     

Novel Lewis-base ionic liquids replacing typical anions

We have synthesized two kinds of new Lewis-base ionic liquids (ILs); one is based on the relatively strong Lewis basic acetate anion, and the other is a salt composed of a mono-alkylated diamine such that the Lewis base site is incorporated in the cation. 1-Octyl-4-aza-1-azonia-bicyclo[2.2.2]octane bis(trifluoromethanesulfonyl)amide, [C₈dabco]TFSA, and N-butyl-N-methylpyrrolidinium acetate, [p_1,4]OAc, melted into fluid liquids at 26 and 81 °C, respectively. The thermal decomposition of [p_1,4]OAc started at around 150 °C, whereas the thermal stability of [C₈dabco]TFSA was almost equal to that of typical TFSA-based ILs in spite of the Lewis base site. This suggests that if the Lewis base site is incorporated into the cation the IL can maintain higher thermal stability. In addition, as a further result of the presence of the basic nitrogen, [C₈dabco]TFSA can dissolve hydrated Cu(NO₃)₂ whereas the other TFSA-based ILs cannot.     

The influence of cyclodextrin complexation on proton transfer in piperidinomethyl-2-naphthol

Summary Piperidinomethyl-2-naphthol forms inclusion complexes with -cyclodextrin with an equilibrium constant of 265M ^–1 in aqueous solution. The proton transfer equilibrium between the neutral and the zwitterionic form is strongly influenced by the association.

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Der Einfluß der Komplexierung mit -Cyclodextrin auf das Protontransfer-Gleichgewicht in Piperidino-2-naphthol (Kurze Mitt.)

Zusammenfassung Piperidinomethyl-2-naphthol bildet Einschlußkomplexe mit -Cyclodextrin mit einer Gleichgewichtskonstante von 265M ^–1. Das Protontransfer-Gleichgewicht zwischen neutraler Form und zwitterionischer Struktur wird durch diese Assoziation stark beeinflußt.

     

Electrochemical behaviour of a series of Fe(III) complexes with tetradentate Schiff base ligands

Summary The electrochemical reduction of the Fe(III) complexes with a series of substituted N,N-Ethylenebisacetonimines was investigated by cyclic voltammetry in acetonitrile solution at a platinum electrode. The substituent does not significantly influence the redox properties of the studied complexes. The symmetry of the redox orbital is responsible for the observed behaviour of the complexes.

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Elektrochemisches Verhalten einer Reihe von Fe(III)-Komplexen mit vierzähnigen Schiffschen Basen als Liganden

Zusammenfassung Die elektrochemische Reduktion der Fe(III)-Komplexe einer Reihe von substituierten N,N-Ethylenbisacetoniminen wurde mittels cyclischer Voltammetrie in Acetonitril an einer Platinelektrode untersucht. Der Substituent beeinflußt die Redoxeigenschaften der untersuchten Komplexe nicht signifikant. Das beobachtete Verhalten der Komplexe wird von der Symmetrie des Redoxorbitals bestimmt.