K4[Fe(CN)6]作为氰源在氰基化反应中的应用**

过渡金属催化氰基化反应成为合成芳基腈化物的重要手段之一。2004年,无毒、廉价的K4[Fe(CN)6]首次被用来代替传统的KCN、NaCN及CuCN等作为氰源用于芳基卤代物的氰基化反应。K4[Fe(CN)6]作为氰源时无需复杂的预处理,其6个氰根均可参与反应。该反应为氰基化反应开创了一个新的研究方向,迅速得到了众多研究者的青睐。K4[Fe(CN)6]用于氰基化反应的研究也得到了较快的发展。本文主要综述了近年来K4[Fe(CN)6]作为氰源用于卤代芳烃和芳基氟代磺酸酯的氰基化反应。主要介绍了在钯催化剂和铜催化剂作用下,以K4[Fe(CN)6]为氰源的氰基化反应在配体、反应介质和底物适用范围等方面的研究成果。     

Synthesis of 5H-imidazo[5,1-a]isoindole: Photocyclization of N,N′ -bis(o-chlorobenzyl)imidazolium chloride and N-(o-chlorobenzyl)imidazole

A N-heterocyclic compound containing two hetero atoms, imidazo[5,1-a]isoindole, was synthesized in 40% yield by the intramolecular photocyclization of N,N'-bis(o-chlorobenzyl)imidazolium salts 1 in water (neutral or pH ～4) or of N-(o-chlorobenzyl)imidazole 2 , in aqueous acid (pH ?4). However, the photocyclized compound 3 was not formed effectively in basic aqueous solution (3 equivalents of sodium hydroxide or pyridine) or in acetonitrile by the photochemical reaction of N,N'-bis(o-chlorobenzyl)imidazolium salts 1 or N-(o-chlorobenzyl)imidazole (2).     

Complexation of dirhodium(II) with N-functionalized calix[4]resorcinarenes

Russian Chemical Bulletin - Some features of the complexation of [Rh2(OAc)4?2H2O] with calix[4]resorcinarenes functionalized by aminoalkyl groups in the upper or lower rims in EtOH and Me2CO...     

Synthesis of the 5H-pyrrolo[2,1-a]isoindole ring with 1,3-dipolar cycloaddition reactions

The 1,3-dipolar cycloaddition reaction between mesoionic oxazolines, formed from either 1,3-dihydro-2-substituted-2H-isoindole-1-carboxylic acids or 1,3-dihydro-1-oxo-α-substituted-2H-isoindole-2-acetic acids, and dimethylacetylene dicarboxylate has led to the synthesis of several 5H-pyrrolo[2,1-a]isoindole derivatives 9a-d .     

Sorption of Hexacyanoferrate(II,III) Anions on Nickel(II) Hydroxide

Fe(CN)₆ ^{3 -} and Fe(CN)₆ ^{4 -} anions are sorbed from aqueous solutions of their potassium and cesium salts on -Ni(OH)2 by the mechanism of anion exchange with hydroxy groups. Alkali metal cations (K⁺, Cs⁺) are also partly sorbed on nickel(II) hydroxide in the form of anionic complexes (K,Cs) _z Fe(CN)₆ ^{(n - z)-}, where n = 3 or 4 (0 < z < n). The chemical composition of the new phase appearing in contact of nickel(II) hydroxide with aqueous potassium and cesium hexacyanoferrates(II, III) was determined by X-ray phase analysis and IR spectroscopy.     

The Solid State Electrochemistry of Dysprosium(III) Hexacyanoferrate(II)

A new electroactive polynuclear inorganic compound of rare earth metal hexacyanoferrate, dysprosium hexacyanoferrate (DyHCF), was prepared chemically and characterized using techniques of FTIR spectroscopy, thermogravimetric analysis (TGA), UV‐vis spectrometry and X‐ray photoelectron spectroscopy (XPS) etc. The cyclic voltammetric behavior of DyHCF mechanically attached to the surface of graphite electrode was well defined and exhibited a pair of redox peaks with the formal potential of 217 mV (vs. SCE) at a scan rate of 100 mV/s in 0.2 M NaCl solution and the redox peak currents increased linearly with the square root of the scan rates.     

Triazolopyridines. Part 8.1 Nucleophilic substitution reactions of 5-bromo[1,2,3]triazolo[5,1-a]isoquinoline and 7-bromo[1,2,3]-triazolo[1,5-a]pyridine

Nucleophilic substitution of 5-bromotriazoloisoquinoline (3) and of 7-bromo-3-methyltriazolopyridine (6) proceeds readily to give a range of 5-substituted triazoloisoquinolines (4a)-(4e), and of 7-substituted triazolopyridines (7a)-(7h) respectively. Triazoloisoquinolines have been converted into 1,3-disubstituted isoquinolines (11)-(13), (15), and (16), and triazolopyridines into 2,6-disubstituted pyridines (17)-(19). Of secondary amine nucleophiles, only piperidine reacted with 7-bromo-3-methyltriazolopyridine (6) to give the 7-substituted derivative (7g). A second product in this reaction was a 2,6-disubstituted pyridine (8); the similar compounds (20)-(24) were the only products when morpholine or N-acetylpiperazine were used. The reaction between 7-bromotriazolopyridine (9) and piperidine or morpholine gave in high yield the 2,6-disubstituted pyridines (25) and (26).     

Silver triflate-copper(II) acetate cooperative catalysis in a cascade reaction for concise synthesis of 2-carbonyl H-pyrazolo[5,1-a]isoquinolines

A cascade reaction of N'-(2-alkynylbenzylidene)hydrazide with allenoate in the presence of dioxygen co-catalyzed by silver triflate and copper(II) acetate under mild conditions is described, which provides an efficient approach to 2-carbonyl H-pyrazolo[5,1-a]isoquinolines.     

Characterization of copper(II) coordination compounds of 5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine: the crystal structure of diaquatetrakis(5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine-N3)-copper(II) hexafluorophosphate

Copper(II) coordination compounds of several CuA₂ salts (A = PF₆, BF₄, ClO₄, CF₃SO₃ or NO₃) with 5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine (dmtp) as a ligand have been studied. The crystal structure of [Cu(dmtp)₄(H₂O)₂](PF₆)₂ is described. This compound is monoclinic, space group P2₁/c, a = 11.826(2) Å, b = 9.463(2) Å, c = 17.673(3) Å, β = 97.50(1)°, Z = 2, d_calc. = 1.66 Mg m⁻³, and has been refined to a final discrepancy factor (R) of 0.0382 based on 2316 reflections. The structure consists of PF⁻₆ anions and centrosymmetric mononuclear [Cu(dmtp)₄(H₂O)₂]²⁺ cations, Cu₂₊ being coordinated by four equatorial N(3)-bonded dmtp molecules with CuN = 2.019 and 2.050 Å, and by two axial water molecules with CuO = 2.650 Å. The water molecules form intramolecular hydrogen bonds with the dmtp N(4) atoms.     

Synthesis of H-pyrazolo[5,1-a]isoquinolines via copper(II)-catalyzed oxidation of an aliphatic C-H bond of tertiary amine in air

A multicomponent reaction of 2-alkynylbenzaldehyde, sulfonohydrazide, and tertiary amine is discovered, which generates the unexpected H-pyrazolo[5,1-a]isoquinolines in good yields under mild conditions. In the reaction process, silver(I)-catalyzed intramolecular cyclization and copper(II)-catalyzed oxidation of an aliphatic C-H bond of tertiary amine in air are involved.     

Condensation of the isoindole–isoindoline isomers of the thieno[3′,2′:5,6]pyrimido[2,1-a]isoindol-6(10H)-one with aldehydes

The reaction of the isoindole–isoindoline isomers of the thieno[3′,2′:5,6]pyrimido[2,1-a]isoindol-6(10H)-one with aldehydes gives new benzylidene thieno[3′,2′:5,6]pyrimido[2,1-a]isoindol-6(10H)-one derivatives. The structures were assessed with NMR, UV spectroscopy and mass spectra.     

Thin-Layer Chromatography of Anions — Separation of Coexisting Hexacyanoferrate(II), Hexacyanoferrate(III) and Thiocyanate with a New Mobile Phase

JPC – Journal of Planar Chromatography – Modern TLC - The thin-layer chromatography of eighteen anions has been performed on silica layers with mixed aqueous–organic mobile...     

Cycloaddition reactions of N-p-toluenesulfonylimino derivatives of quinoline and isoquinoline. A route to pyrazolo[1,5-a]quinolines and pyrazolo[5,1-a]isoquinolines

N-p-Toluenesulfonylimino ylides of quinoline and isoquinoline give cycloadducts with electrophilic acetylenes at 105°. The adducts are spontaneously aromatized under the conditions of their formation by elimination of p-toluenesulfmic acid to give pyrazolo[1,5-a]quinolines and pyrazolo[5,1-a]isoquinolines, respectively. The orientation of cycloaddition is the same as for N-amino ylides for acetylenic esters. The ad-ducts from p-nitrophenylacetylene are formed by addition of the imino nitrogen to the unsubstituted acetylenic carbon. The orientation and unreactivity of phenylacetylene indicate that the cycloaddition is controlled by dipole HOMO-dipolarophile LUMO interactions.