Regioselective synthesis of fluoroalkylated [1,2,3]-triazoles by Huisgen cycloaddition

A series of fluoroalkylated 1,4-disubstituted [1,2,3]-triazoles were synthesized by the 1,3-dipolar cycloaddition of fluoroalkylated azides with terminal alkynes in the presence of Cu(I) salt as catalyst at room temperature. All the reactions were performed in highly regioselective with 1,4-disubstituted, no 1,5-disubstituted product was formed. For aryl or alkyl-alkyne, triethylamine should be used as ligand. But for propiolic ester(amide), triethylamine couldn’t be used, otherwise no products was formed. A mechanism of Cu(I) inserting the internal alkyne was suggested.     

Temperature-dependent crystal structure and fluorescence properties of a tetranuclear copper(I) cluster from in situ [2 + 3] cycloaddition synthesis

Hydrothermal reaction of CuSO₄·7H₂O and NaN₃ with 2-cyanothiophene in aqueous ethanol yielded a novel tetranuclear copper(I) polymer, {[Cu₄(tptz)₄]·0.5(C₂H₆O)}_n (1) (Htptz = 5-(thiophen-2-yl)-1H-tetrazole). The tptz ligand in the complex was generated through an in situ [2 + 3] cycloaddition reaction involving the cyano groups of the precursor 2-cyanothiophene. In a rare example, three different geometries of Cu(I) cations, namely the linear, triangle, and tetrahedron geometries of Cu(I) centers, are created and linked by Htptz ligands into a 1-D ladder structure. Additionally, 1 exhibits strong blue fluorescence (with λ = 467 nm) at room temperature in the solid state.     

Solid State Synthesis and Structural Characterization of Binuclear Cu(I)-SbPh3 Complex [Cu(SbPh3)2I]2

Dimeric complex [Cu(SbPh3)2I]2 has been synthesized by a solid state reaction at a low heating temperature and its crystal structure has been analyzed by X-ray crystallography. The crystal is monoclinic, space group P21/a (#14), a = 20.436(5), b=14.125(3), c=24.683(3)(A), β=110.67(1)°, Z=4, V=6666(2)(A)3; C72H60Sb4I2Cu2, Mr = 1792, Dc = 1.787 g.cm-3, μ(MoKα) = 31.88 cm-1, F(000)=3440, R=0.038 and Rw=0.043 for 5632 observed reflections (I≥3.0σ(I)) and 361 refined parameters. The result reveals the copper and the bridging iodide atoms form an approximately planar rhomboid array. Effects of the bulkiness of the ligands upon the structures of the analogous complexes are discussed.     

Cu(I) mediated one-pot synthesis of azobenzenes from bis-Boc aryl hydrazines and aryl halides

N,N^′-bis-Boc aryl hydrazines underwent Cu(I) catalyzed couplings with aryl halides to provide N,N^′-bis-Boc diaryl hydrazines. The resulting N,N^′-bis-Boc diaryl hydrazines are readily oxidized to the azobenzenes in the presence of Cu(I) and a base. A prolonged heating of the initial coupling reactions directly provides the corresponding azobenzenes in one pot.     

一价铜配合物〔Cu（C_8H_4F_3O_2S）（PPh_3）_2〕的合成和晶体

室温下，铜粉和２－噻吩甲酰三氟丙酮、三苯基膦在甲醇和四氢呋喃混合溶剂中反应，生成一价铜的配合物［Ｃｕ（Ｃ_８Ｈ_４Ｆ_３Ｏ_２Ｓ）（ＰＰｈ_３）_２］，测定了该配合物的晶体结构，结果表明，晶体属单斜晶系，Ｐ２_１／ｎ空间群，晶胞参数：ａ＝１０．５８４（１），ｂ＝１６．７３８（１），ｃ＝２２．７２８（９）Ａ；β＝９４．２２（２）°，Ｖ＝４０１５．２Ａ３，Ｍｒ＝７８５．２９，Ｚ＝４，Ｄｃ＝１０２９９ｇ／ｃｍ３，μ＝９．８６ｃｍ－１。晶体结构由直接法解出，使用块对角矩阵和全矩阵最小二乘法对原子参数进行修正，最后偏离因子Ｒ＝０．０４８，Ｒｗ＝０．０５４，其中４３９１个Ｉ＞３σ（Ｉ）的可观察衍射点参加了结构修正，结果表明，Ｃｕ原子由２个Ｏ原子和２个Ｐ原子配位，形成畸变四面体构型。     

Regioselective synthesis of C-prenylated flavonoids via intramolecular [1,3] or [1,5] shift reaction catalyzed by acidic clays

Prenyl side chain and dihydropyrano skeleton exists in many natural and synthetic biologically active flavonoids. A highly efficient and regioselective method for the synthesis of C-prenylated flavonoids via intramolecular [1,3] or [1,5] shift reaction of 5-O-prenylflavonoids catalyzed by Florisil or Montmorillonite clays is described. Florisil catalyzes intramolecular [1,5] shift reaction of 5-O-prenylflavonoids to obtain 8-C-prenylated flavonoids exclusively, Montmorillonite K10 exhibits the superior selectivity to promote intramolecular [1,3] shift reaction to obtain 6-C-prenylated flavonoids compared with Florisil and Montmorillonite KSF. This method provides a practical process to regioselective synthesize biologically important C-prenylated flavonoids in good yields using commercially available and inexpensive catalyst under mild conditions.     

Synthesis, spectroscopic characterization and electronic structure of some new Cu(I) carbene complexes

Reaction of oligomeric Cu(I) complexes [Cu(Μ-S-C(=NR)(O-Ar-CH₃)]_n with Lewis acids gave Cu(I) carbene complexes, which were characterized by¹H and¹³C NMR spectroscopy. Cu(I) carbene complexes could be directly generated from RNCS, Cu(I)-OAr and Lewis acids; this method can be used to prepare Cu(I) carbene complexes with different substitutents on the carbene carbon. The complexes were unreactive towards olefins and do not undergo cyclopropanation. Electronic structure calculations (DFT) show that the charge on the carbene carbon plays an important role in controlling the reactivity of the carbene complex.     

Synthesis,structure, and catalytic activity of Keggin-type polyoxometalate coordinated Cu(I): {[Cu(py)2]4[SiW12O40]}, via hydrothermal decarboxylation

A Keggin-type polyoxometalate [SiW₁₂O₄₀]^4? supported transition metal complex, {[Cu(py)₂]₄[SiW₁₂O₄₀]} (py?=?pyridine), has been synthesized by hydrothermal decarboxylation and characterized by elemental analyses, IR spectra, thermal stability analyses, and single-crystal X-ray diffraction. The compound is a 1-D chain containing an inorganic–organic backbone with alternating [SiW₁₂O₄₀]^4? clusters and [Cu(py)₂]⁺ along the c-axis, and with both three- and four-coordinate copper. The luminescence properties indicated that the emission peak is emission of pyridine, assigned to the Cu(I) to pyridine charge transfer. This air-stable Cu(I) complex can efficiently catalyze the O-arylation of both phenols and aryl halides.     

Regioselective synthesis of 1,5-disubstituted 1,2,3-triazoles by 1,3-dipolar cycloaddition: Role of Er(OTf)3, ionic liquid and water

A simple procedure to obtain 1,5-disubstituted 1,2,3-triazoles, using the Er(OTf)₃/[mpy]OTf/H₂O catalytic system is described. The reaction proceeds through an eliminative azide–olefin cycloaddition (EAOC) offering a highly regioselective approach and good yields (81–94%). The advantages of this method include simple operations of work-up and the ability of the catalytic system to be re-used five times without an evident loss in yield. The role of IL and water were speculated, invoking also a probable ionic self-assembly (ISA) effect.     

Solid State Synthesis and Structural Characterizationof Binuclear Cu( I)-Sb Ph_3 Co m plex 〔 Cu( Sb Ph_3)_2 I〕

１　ＩＮＴＲＯＤＵＣＴＩＯＮＣｕ（Ｉ）ｃｏｍｐｌｅｘｅｓｗｉｔｈｐｈｏｓｐｈｉｎｅａｎｄａｒｓｉｎｅｌｉｇａｎｄｓａｒｅｗｅｌｌｋｎｏｗｎ〔１〕．ＦｏｒＣｕｐｈｏｓｐｈｉｎｅｃｏｍｐｌｅｘｅｓ，ｔｈｅＣｕ∶ｌｉｇａｎｄｒａｔｉｏｖａｒｉｅｓｆｒｏｍ１∶１ｔｏ１∶４ａｎｄｃｏｏｒｄｉｎａｔｉｏｎｇｅｏｍｅｔｒｙｏｆＣｕ（Ｉ）ｒａｎｇｅｓｆｒｏｍｌｉｎｅａｒｔｏｔｒｉｇｏｎａｌ，ｔｈｅｎｔｏｔｅｔｒａｈｅｄｒａｌｅｘｔｒｅｍｅｓ；ｆｏｒｅｘａｍｐｌｅ，ｔｈｅ１∶２ａｄｄｕｃｔｓＣｕ（ＰＰｈ３）…     

Two New Modifications of [P(C6H5)4]2[Cu2I4]

Single crystals of two new modifications of [P(C₆H₅)₄]₂[Cu₂I₄] were obtained by reaction of granulated copper with iodine and [P(C₆H₅)₄]I in dry acetone under nitrogen atmosphere. They crystallise monoclinically, space group P2₁/n (No. 14), a = 11.550(6), b = 7.236(2), c = 27.232(13) Å, β = 98.13(3)°, V = 2253(2) ų, and Z = 2 ([P(C₆H₅)₄]₂[Cu₂I₄]-C), and space group Cc (No. 9), a = 17.133(5), b = 15.941(5), c = 18.762 (6) Å, β = 114.02(1)°, V = 4681(3) ų, and Z = 4 ([P(C₆H₅)₄]₂[Cu₂I₄]-D), respectively. In these compounds the [CuI₂]^? anions form dimers di-μ-iodo-diiodocuprate(I), which are either planar ( C ) or folded ( D ).     

Efficient N-arylation catalyzed by a copper(I) pyrazolyl-nicotinic acid system

Catalyst 6-(1H-pyrazol-1-yl)nicotinic acid L-CuCl behaves as a very active promoter of the N-arylation reactions, as it has been demonstrated with varieties of substrates under mild reaction conditions. A Cu(I) complex based on L of precatalyst has been isolated by a hydrothermal method and structurally characterized.     

Synthesis,spectroscopic and electrochemical characterization of copper(I) complexes with functionalized pyrazino[2,3-f]-1,10-phenanthroline

The present work reports the synthesis and spectroscopic and electrochemical characterization of homoleptic copper(I) complexes with substituted pirazino [2,3-f]-1,10-phenanthroline, RpplR′, (R = H, Me, COOH or COOMe, and R′ = H, Me) as ligand. The ligand ppl works as an acceptor of electronic density, which is delocalized mainly in the quinoxaline part of its structure. The UV–Vis spectra show that all the complexes display bands in the range 400–650 nm, which are MLCT in character. The λ_max and extinction coefficients of the MLCT band at 450 nm and the LC band do not change significatively when varying the R substituent. Nevertheless, the intensity of the shoulder around 500 nm does change; this absorption has been related to either a static or dynamic flattening distortion of the complex D_2d → D₂ symmetry. The cyclic voltammetry of the complexes shows irreversible redox processes with E_p values that do not follow the tendency expected from the donor/acceptor character of the substituents on the ligand. All the complexes studied showed no emission both in acetonitrile and dichloromethane as solvent at room temperature and under argon atmosphere.     

One-pot synthesis of 1,4-disubstituted 1,2,3-triazoles from terminal acetylenes and in situ generated azides

1,4-Disubstituted 1,2,3-triazoles were obtained by a high-yielding copper(I) catalyzed 1,3-dipolar cycloaddition reaction between in situ generated azides and terminal acetylenes. This one-pot, two-step procedure tolerates most functional groups and circumvents the problems associated with the isolation of potentially toxic and explosive organic azides.     

Synthesis,crystal structure and magnetic properties of a new complex containing Cu(I) and radicals, [Cu(imme2py)2](ClO4)

A new complex, [Cu(imme2py)₂](ClO₄) (imme2py?=?2-(2′-(6′-methylpyridyl))-4,4,5,5-tetramethyl-1H-imidazolyl-1-oxyl) has been synthesized and structurally characterized by X-ray diffraction methods. It crystallizes in the orthorhombic crystal system, space group P ₂₁₂₁₂₁ . The structure consists of [Cu(imme2py)₂]⁺ cations and chloride anions. The coordination geometry about Cu(I) is tetrahedral with the four coordination sites being occupied by four nitrogen atoms. Magnetic measurements show intramolecular antiferromagnetic interactions between the imino nitroxides.     

Alkyl chain self ordering,induction and suppression of mesophase by Cu(II) containing [1,2,3]-triazole-based bidentate salicylaldimine ligands: synthesis,characterisation and X-ray diffraction studies

Some new Cu(II) complexes containing [1,2,3]-triazole-based bidentate salicylaldimine and its analogues with terminal substituent (F, Cl, Br and I) have been synthesieed. All the target complexes and their uncoordinated ligands were elucidated by elemental analysis and spectroscopic techniques (UV-visible, FT-IR, 1D, 2D ¹H and ¹³C-NMR). The polarising optical microscope and differential scanning calorimetry (DSC) have disclosed all complexes and ligands are mesomorphic except the complex without any terminal substituent. The fluoro-substituted complexes with even parity C₁₄H₂₉ and C₁₆H₃₃ exhibit new enantiotropic nematic phase which was absent in their corresponding ligands, whereas the suppression of SmC phase occurred for all complexes with longer C₁₆H₃₃ and C₁₈H₃₇. X-ray diffraction confirmed the existence of SmA, SmC and N phases for complexes and ligands. The other notable feature is that the self-ordering of terminal alkyl chain occurred in SmA and SmC phases of complexes with even terminal alkyl chain ranging from C₁₄H₂₉ to C₁₈H₃₃. Their corresponding ligands exhibit intercalated structure of SmA and SmC phases. The thermal behaviour studies show that the fluoro-substituted triazole-based complexes possess lowest phase transition temperature and more stable as compared to other substituent which decomposed during the isotropisation.     

DBBD及其Cu(I)配位聚合物[CuI(DBBD)2]n的合成

In this article we report the synthesis of (R,S)-4,4′-biquinoline-6,6′-dimethyl-3,3′-dicarboxylate (DBBD) (1) and the formation of copper(I) coordination polymer [CuI(DBBD)₂]_n (2) by inducing a bidentate organic ligand (DBBD). The crystal 1 belongs to monoclinic system with space group P2₁, and a=0.881 30(19) nm, b=1.966 0(6) nm, c=1.478 1(4) nm, β=119.429(12)°, V=2.230 5(10) nm³, D_c=1.276 g·cm^-3. The crystal 2 belongs to orthogonal system with space group Fmm2, and a=2.044 41(17) nm, b=1.543 06(13) nm, c=1.652 45(13) nm, V=5.212 9(7) nm³, D_c=1.669 g·cm^-3, Z=8. CCDC: 292931, 1; 292934, 2.     

Crystal structure and interaction with bovine serum albumin of the Cu(I/II) complex [C20H32Cu2I3N4] n

[C₂₀H₃₂Cu₂I₃N₄] _n was synthesized and characterized by elemental analysis, ESI-MS spectrometry, and IR spectra. The crystal structure was determined by X-ray single-crystal diffraction. The binding of the complex with bovine serum albumin (BSA) was studied by fluorescence spectroscopy under simulated physiological conditions. The binding constant (K _b), the number of binding sites (n), and the corresponding thermodynamic parameters ΔH, ΔS, ΔG were calculated based on the van’t Hoff equation. The complex had strong ability to quench the fluorescence from BSA, and the quenching mechanism of this complex to BSA was static quenching. Hydrogen bonds and van der Waals forces are the interactions between the Cu(I/II) complex and BSA. According to the Förster non-radiation energy transfer theory, the binding average distance between the donor (BSA) and the acceptor (Cu(I/II) complex) was obtained. The effect of the complex on the BSA conformation was also studied by using synchronous fluorescence spectroscopy.     

Cu(I) and Ag(I) complexes of chalcogenide derivatives of the organometallic ligand dppf and the dppa analogue

New Cu(I) and Ag(I) complexes were prepared by reaction of [M(NCCH₃)₄][X] (M = Cu or Ag; X = BF₄ or PF₆) with the bidentate chalcogenide ligands Ph₂P(E)NHP(E)Ph₂ (E = S, S₂dppa; E = Se, Se₂dppa), and dpspf (1,1′-bis(diphenylselenophosphoryl)ferrocene). Copper and silver behaved differently. While three molecules of either S₂dppa and Se₂dppa bind to a distorted tetrahedral Cu₄ cluster, with deprotonation of the ligand, 1:2 complexes of the neutral ligands are formed with Ag(I), with a tetrahedral coordination of the metal. The [Cu₄{Ph₂P(Se)NP(Se)Ph₂}₃]⁺ clusters assemble as dimers, held together by weak Se?Se distances interactions. Another dimer was observed for the [Ag(dpspf)]⁺ cation, with two short Ag?Se distances. DFT and MP2 calculations indicated the presence of attracting interactions, reflected in positive Mayer indices (MI). The electrochemistry study of this species showed that both oxidation and reduction took place at silver.     

Tetramethylcyclotetraarsoxane Bridging of Copper(I) Halide Units Cu6Br6, Cu2I2, [Cu6I8]2–, and [Cu3I4–] in Porous Coordination Polymers

The polymeric compounds [{Cu₂I₂(C₆H₅CN)₂[cyclo‐(CH₃AsO)₄]} · C₆H₅CN] ( 1 ) and [Cu₆Br₆(C₆H₅CN)₄{cyclo‐(CH₃AsO)₄}] ( 2 ) may be prepared by reaction of the copper(I) halide with methylcycloarsoxane (CH₃AsO)_n in benzonitrile at 100 °C. 1 contains four‐membered (CuI)₂ rings, 2 tricyclic Cu₆Br₆ units, that are connected through bridging (CH₃AsO)₄ ligands into infinite chains. π–π Stacking of terminal C₆H₅CN ligands from parallel chains leads to the construction of porous frameworks, whose cavities are large enough in the case of 1 to accommodate guest C₆H₅CN molecules. In the presence of CsI, the self‐assembly reaction of CuI with (CH₃AsO)₄ in H₂O–CH₃OH–CH₃CN (at 20 °C) or CH₃CN (at 130 °C) affords [Cs(H₂O)₂][Cu₃I₄{cyclo‐(CH₃AsO)₄}₂] · 0.5 CH₃OH ( 3 ) and Cs[Cu₃I₄{cyclo‐(CH₃AsO)₄}₂] ( 4 ), whose 1‐ and 2‐dimensional anionic coordination polymers are linked together through respectively [Cs{cyclo‐(CH₃AsO)₄‐κ⁴O}₂]⁺ and [Cs{Cu₃I₄‐κ⁴I}{cyclo‐(CH₃AsO)₄‐κ⁴O}] sandwiches.