Cobalt-catalyzed photopromoted carbonylation of chloroalkanes in the presence of KI

<正>The photopromoted carbonylation of chloroalkanes with carbon monoxide catalyzed by cobalt compounds[Co(OAc)_2,CoCl_2] in the presence of KI was carried out under ambient conditions.The results revealed that the catalytic activity of Co(OAc)_2 was higher than that of CoCl_2.A basic additive NaOAc was beneficial to the reaction.Interestingly,with NaOAc as an additive, Co(OAc)_2 and CoCl_2 exhibited similar catalytic activity.Preliminary work showed that the role of iodide ion was initially to form active iodoalkanes via substituting chloride ion in chloroalkanes in situ,and then,the carbonylation of iodoalkanes proceeded under irradiation.     

Cu(Ⅱ)-catalyzed aerobic oxidative amidation of azoarenes with amides

A method for Cu(Ⅱ)-catalyzed dehydrogenative amidation of azoarene using air as the terminal oxidant was developed. Various amides, such as arylamides, alkylamides, lactams, and imides, are all effective amidation reagents and provide the desired products in moderate to excellent yields. Notably, good yields can also be obtained on a gram-scale with this amidation reaction.In this protocol of azoarene amidation, the catalyst(Cu(OAc)_2) and oxidant(air) are inexpensive and readily available, and the process is highly efficient and atom economical.     

Copper-mediated 1,4-conjugation reaction of functionalized alkylzinc iodides with derivatives of β-nitrostyrene

Functionalized alkylzinc iodides will undergo 1,4-conjugation reaction with derivatives ofβ-nitrostyrene in the presence of Cu(OAc)_2/LiCl to afford a polyfunctional nitro-compound in high yield.     

PhI(OAc)_2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones

Umpolung is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)_2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy ketones in good to excellent yields. PhI(OAc)_2 serves as a source of acetoxy in the reaction.     

The solid state reactions of o-aminobenzoic acid with Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Mn(Ⅱ) acetate hydrate at room temperature

The solid-solid state reactions of o-aminobenzoic acid with Zn(OAc)2.2H2O, Cu(OAc)2 .H2O, Ni(OAc)2.4H2O and Mn(OAc)2.4H2O result in the formation of corresponding complexes M(OAB)2 (M = Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Mn(IⅡ)). XRD, IR and elemental analysis methods have been used to characterize the solid products. The activation energies of these reactions, which are calculated from the kinetic data obtained by means of the isothermal electrical conductivity measurement method, have been found to increase in the order: Cu(OAc)2.H2O(37.7 kJ.mol-1)~Mn(OAc)2.4H2O (39.7kJ.mol-1) < Zn(OAc)2.2H2O (56.3 kJ.mol-1) < Ni(OAc)2.4H2O (85.2 kJ.mol-1). The trend is related to their crystal structures.     

Theoretical Analysis of the Mechanism of Cationic Pd(Ⅱ)-catalyzed Fujiwara-Moritani Reaction

A systematic theoretical investigation has been studied on Fujiwara-Moritani reaction between 3-methoxyacetanilide with n-butyl acrylate by means of density functional theory(DFT) calculations when two types of Pd(Ⅱ) catalysts are employed. In [Pd(MeCN)_4](BF_4)_2 catalytic cycle, a 1,4-benzoquinone(BQ)-induced C-H activation of trans-(MeCN)_2Pd(BQ)~(2+) with 3-methoxyacetanilide occurs as the first step to give DC-4_(MeCN), facilitating the insertion of n-butyl acrylate and β-hydride elimination, followed by recycling of catalyst through hydrogen abstraction of monocationic BQ fragment. In Pd(OAc)_2 catalytic cycle, it is proposed that the most favored reaction pathway should proceed in dicationic mechanism involving a BQ-assisted hydrogen transfer for C-H activation by Pd active catalyst(HOAc)_2Pd(BQ)~(2+) to generate DC-4_(HOAc), promoting acrylate insertion and β-hydride elimination, followed by the regeneration of catalyst to give the final product. The calculations indicate that the rate-determining step in [Pd(MeCN)_4](BF_4)_2 catalytic system is the acrylate insertion, while it is the regeneration of catalyst in the Pd(OAc)_2 catalytic system. In particular, the roles of BQ and ligand effects have also been investigated.     

Rhodium catalyzed regioselective arene homologation of aryl urea via double C–H bond activation and migratory insertion of alkyne

A convenient rhodium catalyzed oxidative arene homologation of aniline derivatives with symmetrical or unsymmetrical alkynes using Cu(OAc)_2 as oxidant is described. Urea group is shown to be effective as a directing group for initial ortho C–H activation. Two migratory insertion events of alkyne into Rh–C bond occur successively, both with complete regioselectivity. This method is particularly useful for synthesis of polyarenes with different substituents, which has not been reported with conventional protocol. A mechanism has been proposed to explain the observed data.     

A 2D Layer Copper(Ⅱ) Coordination Polymer with 3-Nitrophthalic Acid: Synthesis,Crystal Structure and Copper 3-Nitrophthalate Metal-organic Framework-graphene Oxide Nanocomposite

A 2D layer Cu(Ⅱ) coordination polymer [Cu(npth)(H_2O)]n(1) was crystallized from a mixture of 3-nitrophthalic acid and Cu(OAc)_2·H_2O in water under room temperature and structurally characterized by single-crystal X-ray diffraction, FT-IR and TGA. Compound 1 was applied to make a nanocomposite with graphene oxide(GO). A highly dispersible and stable nanocomposite of Cu(npth)-GO was successfully synthesized by a simple ultrasonication method. SEM, TEM, UV-vis, FT-IR and TGA were used to characterize the morphology and structure of the prepared composite. In accordance with the characterization results, we suspected that the binding mechanism of Cu(npth) and GO was assigned to be the cooperative interaction of Cu–O coordination, π-π stacking and hydrogen bonding.     

Synthesis and Crystal Structures of Two Di-Cu(Ⅱ) Complexes Based on an Asymmetric Dinucleating Ligand

Two new dicopper(II) complexes [Cu2L(OAc)2](ClO4)·H2O(1) and [Cu2L(BPP)2]-(ClO4)(2) using an asymmetric dinucleating ligand HL and auxiliary ligands such as acetate(OAc) and bisphenyl phosphate(BPP) have been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. Complex 1 crystallizes as blue single crystals that belong to the triclinic crystal system and P1 space group, while complex 2 crystallizes in a monoclinic P21/c space group. Single-crystal X-ray diffraction analysis reveals that the two copper ions in complexes 1 and 2 reside within the adjacent ligand compartments and are bridged by the endogenous phenoxo-O from ligand L and the introduction of two desired exogenous carboxylates or phosphates in the bidentate μ-1,3-bridged mode. The coordination geometries of Cu(1) and Cu(2) are both distorted square pyramids.     

Unexpected Side Reaction in the Intermolecular N-H Insertion of Phenyl Diazoacetates with Arylamines

Unexpected side reaction is discovered from the N-H insertion of phenyl diazoacetates with arylamines in the presence of Rh2(OAc)4 catalyst. This side reaction is not evident with copper catalysts such as Cu(acac)2 or Cu(OTf)2. Good yield of the N-H insertion was obtained by using 0.2% of copper catalyst.     

铜（II）化合物作用下2-綦胺的氧化偶合反应

2-萘胺（1）在甲醇中与铜胺络合物[x(CuCl_2):x(苄胺或乙醇胺）=2：1]室温 下反应得到产率为74%的1,1'-联-2-萘胺（2）。在醋酸铜、硝酸铜或高氯酸铜的催 化下,1在甲醇中被氢气氧化为2-氨基-1,4-萘醌-4-2'-萘亚胺（3）,产率86%。 用X-ray单晶衍射证实3的乙酰化产物结构为2-乙酰氨基-1,4-萘醌-E-4-2'-萘亚胺 （4）。循环伏安研究表明,铜（II）化合物的氧化反应选择性与其还原峰电位有 关。电喷雾质谱的分析表明1,2-萘醌-2-亚胺（6）是生成3的中间体。     

Cu（OAc）2/Pyrimidines-Catalyzed Cross-coupling Reactions of Aryl Iodides and Activated Aryl Bromides with Alkynes under Aerobic, Solvent-free and Palladium-free Conditions

Excellent results have been achieved in the Cu（OAc）2-catalyzed Sonogashira cross-couplings of aryl iodides and activated aryl bromides utilizing TBAF （tetrabutylammonium fluoride） as the base and 4,6-dimethoxypyrimidin-2-amine as the ligand. It is noteworthy that the reaction is conducted under aerobic, solvent-free and palladium-free conditions.     

Mn(III)/Cu(II)-mediated oxidative radical cyclization of alpha-(Methylthio)acetamides leading to erythrinanes

Treatment of N-[2-(3,4-dimethoxyphenyl)ethyl]-alpha-(methylthio)acetamide 3 with Mn(OAc)3 in the presence of Cu(OAc)2 gave tetrahydroindol-2-one 4, which then cyclized with Mn(OAc)3 to give 4-acetoxyerythrinane 5. A similar reaction of the 3,4-methylenedioxyphenyl congener 8 also gave tetrahydroindol-2-one 9, which, however, gave only a trace amount of the Mn(OAc)3-mediated cyclization product 11 and afforded the oxidation product 10. On the basis of these results, formation of 5 from 4 was thought to proceed via nucleophilic attack of the pyrrole ring on the cation-radical lX, generated by a single electron-transfer reaction of the acetoxy-substituted intermediate V. Treatment of compound 16 with Mn(OAc)3/Cu(OAc)2 gave no erythrinane derivative with recovery of the starting material, indicating that the presence of a methylthio group of 4 is essential for effecting the formation of erythrinane 5. On the other hand, treatment of 3 with Mn(OAc)3 using Cu(OTf)2 as an additive in place of Cu(OAc)2 gave another erythrinane 17. This method was applied to a formal synthesis of 3-demethoxyerythratidinone (20), a naturally occurring Erythrina alkaloid.     

Pd(OAc)_2/TBAB催化卤代芳烃与末端炔烃的Sonogashira交叉偶联反应研究

研究了无铜、无配体、可回收利用的催化体系[Pd(OAc)2/TBAB]催化卤代芳烃与末端炔烃的Sonogashira交叉偶联反应,高产率地合成了一系列偶联产物,其结构经1H NMR和13C NMR表征。催化实验结果表明,Pd(OAc)2/TBAB可回收重复使用3次,催化活性基本不变。     

不对称加氢催化剂[Ru(BINAP)(OAc)2]的合成及其固载化研究

对文献报道的实验反应条件进行优化改进后,合成了不对称加氢催化剂[Ru((S)-BINAP)(OAc)2]和[Ru((R)-BINAP)(OAc)2]。将合成的催化剂应用于惕各酸的不对称催化氢化,(S)-2-甲基丁酸得率为88%,立体选择性可达85%e.e.。为了提高催化剂的利用率,将催化剂[Ru(BINAP)(OAc)2]负载在新型介孔分子筛SBA-15上,用于惕各酸的不对称催化氢化,循环应用3次后,(S)-2-甲基丁酸得率仍可达到59%,立体选择性达57%e.e.。     

Copper(II) complexes of tridentate N,N,N',N',N'-pentamethyldiethylenetriamine: superoxide dismutase and inhibitory activity against bacteria and fungi

A series of ternary copper(II) complexes containing same coordination sphere but difference in the counter ions, viz., [Cu(PMDT)(OAc)]PF(6)(1); [Cu(PMDT)(OAc)]ClO(4)(2); [Cu(PMDT)(OAc)]BF(4)(3) and [Cu(PMDT)(OAc)]BPh(4)(4) where PMDT=N,N,N',N',N'-pentamethyldiethylenetriamine, OAc=Acetate ion were synthesized and characterized by means of spectroscopic, magnetic and cyclic voltammetric measurements. In frozen solution e.p.r. spectra, an interesting relation g|| >g(perpendicular) has been observed which is atypical of the axially symmetric d(9) Cu(II) (S(Cu)=1/2) having an unpaired electron in a d (x2-y2) orbital. Single crystal X-ray analysis of (1) has revealed the presence of distorted square planar geometry. The influence of the counter ion on the complexes has been examined by performing some biological experiments like superoxide dismutase and anti-microbial activity.     

Highly selective C-H functionalization/halogenation of acetanilide

Highly regioselective C-H functionalization/halogenation of acetanilides to produce ortho-haloacetanilides was catalyzed by Pd(OAc)2 and Cu(OAc) 2 with CuX2 as the halogen source.     

Pt碘乙二胺配合物的DFT和DV-Xα研究

利用密度泛函DFT/LANL2DZ和DV-Xα，对两种Pt(IV)碘配合物trans，cis-[Pt (OAc)_2I_2(en)] (A)，trans，cis-[Pt(OH)_2I_2(en)] (B)及它们的光照产物 [Pt(OAc)_2(OH)I(en)] (C)，[Pt(OH)_3I(en)] (D)完成了几何优化；计算了配合 物能级、光谱、前线轨道组成、电荷布居等性质。计算结果能解释有关的实验现象 。     

Heterobimetallic molecular cages for the deposition of Cu/Ti and Cu/Zn mixed-metal oxides

Heterobimetallic molecular precursors [Ti4(dmae)6(mu-OH)(mu-O)6Cu6(OAc)9.H2O] (1) and [Zn7(OAc)10(mu-OH)6Cu5(dmae)4Cl4] (2) for the deposition of metal oxide thin films of Cu6Ti4O12 (Cu3TiO4, TiO2) and Cu5Zn7O12 (ZnO, CuO) were prepared by the interaction of Ti(dmae)4 with Cu(OAc)2.2H2O for 1 and tetrameric (N,N-dimethylamino)ethanolatocopper(II) chloride, [(dmae)CuCl]4 [where dmae = (N,N-dimethylamino)ethanolate] with Zn(OAc)2.2H2O (where OAc = acetate) for 2 in dry toluene. Both complexes were characterized by melting point, elemental analysis, Fourier transform IR, fast atom bombardment mass spectrometry, thermal analysis (TGA), and single-crystal X-ray diffraction. TGA and XRD prove that complexes 1 and 2 undergo facile thermal decomposition at 300 and 460 degrees C to form thin films of Cu/Ti and Cu/Zn mixed-metal oxides, respectively. Scanning electron microscopy and XRD of the thin films suggest the formation of impurity-free crystallite mixtures of Cu3TiO4 and TiO2, with average crystallite sizes of 22.2 nm from complex 1 and of ZnO and CuO with average crystallite sizes of 26.1 nm from complex 2.     

Efficient and Recyclable Reaction System for the Homocoupling of Terminal Acetylenes

Diynes were synthesized in high yields by homocoupling of terminal arylacetylenes and terminal alkylacetylenes in Cu(OAc)₂‐PEG (polyethyleneglycol) with NaOAc as a base. Cu(OAc)₂‐PEG was readily recycled via solvent precipitation with efficient recyclability.