含杂环二茂铁亚胺异环环钯化合物在Heck反应中的催化活性研究

含杂环二茂铁亚胺异环环钯化合物结构新颖、独特,其催化的Heck偶联反应具有底物范围广、反应条件温和、催化活性高且催化诱导期短等优点。芳基碘代物、芳基溴代物和芳基氯代物都可作为反应底物,其中化合物2应用于芳基溴代物和丙烯酸乙酯的反应得到了100%的收率。在反应中加入四丁基溴化铵,且提高反应温度到140℃,带有斥电子取代基的芳基溴代物、芳基氯代物仍能以较高的产率得到偶联产物。实验中利用薄层色谱监测反应。     

Langmuir-Blodgett films of cyclopalladated ferrocenylimine: preparation, characterization, and application in Suzuki coupling reaction

Langmuir monolayer and Langmuir-Blodgett (LB) films of cyclopalladated ferrocenylimine 1 were prepared and characterized. The surface pressure (π)-area (A) isotherm of complex 1 indicated the formation of highly condensed monolayer on the subphase. Ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopy showed that complex 1 monolayer was transferred successfully onto solid supports. Atomic force microscopy (AFM) image suggested that LB films transferred on the solid substrate were well-ordered, homogeneous. Cyclic voltammograms of LB films deposited on glassy carbon electrodes showed quasi-reversible oxidation/reduction waves of ferrocene moiety. From the average thickness of monolayer, the hydrocarbon chain could be fairly directed perpendicular to the substrates. Finally, LB films of complex 1 presented a largely improved catalytic efficiency for Suzuki reaction with respect to its cast films and homogeneous reactions under the same conditions. The results might have an implication on the catalytic mechanism of this reaction.     

缬氨醇衍生的手性二茂铁亚胺环钯化合物的合成及晶体结构

含氮配位基团的二茂铁衍生物的环钯化合物在有机合成、催化等领或有着重要的应用,尽管目前已经合成了从多的二茂铁环钯化合物,但其中绝大部分为外消旋体。二茂铁是引入平面手性的理想骨架,通过经典的拆分方法或利用光学纯的二茂铁配体进行不对称环钯化反应可得到具有平面手性的二茂铁环钯化合物,研究发现,利用平面手性的二茂铁环钯化合物与金属汞嘲、锡等的金属转移反应可方便地制备平面构型保持的手性环汞、环锡化合物;还可将它们用于外消旋氨基酸的手性拆分及催化不对称Claisen重排反应（ee值最高可达95％）。     

Generally applicable and efficient esterification of aldehydes with alcohols catalyzed by cyclopalladated ferrocenylimine

The palladacycle‐catalyzed esterification of a variety of aldehydes with alcohols was developed. This reaction allows formation of esters in moderate to excellent yields not only for various aldehydes but also alcohols. In addition, the esterification could proceed well under mild conditions with a low catalyst loading of 0.0625 mol%. Copyright © 2013 John Wiley & Sons, Ltd.     

Carbene adduct of cyclopalladated ferrocenylimine as an efficient catalyst for the amination of aryl chlorides

A novel air- and moisture-stable carbene adduct of cyclopalladated ferrocenylimine has been synthesized and characterized. The structure of this compound was determined by X-ray crystal structure analysis. This adduct has been applied as an efficient catalyst for the amination of aryl chlorides.     

Study on the Heck reaction promoted by carbene adduct of cyclopalladated ferrocenylimine and the related reaction mechanism

Carbene adduct of cyclopalladated ferrocenylimine has been successfully applied to Heck reaction of various aryl bromides with olefins. On the basis of kinetic studies, in situ ¹³C NMR spectra investigations and Hg poisoning experiments, it was proposed that the Heck reaction catalyzed by carbene adduct of cyclopalladated ferrocenylimine proceeded through a classical Pd(0)/Pd(II) cycle and such palladacycle was only a reservoir of the catalytically active Pd(0) species.     

Amination of aryl chlorides in water catalyzed by cyclopalladated ferrocenylimine complexes with commercially available monophosphinobiaryl ligands

The easily accessible, air- and moisture-stable cyclopalladated ferrocenylimine complex 3 was found to be a highly active one-component precatalyst for the amination of aryl chlorides in water in the presence of inexpensive KOH and t-BuOH as a base and an additive, respectively.     

Highly efficient cyclopalladated ferrocenylimine catalyst for Suzuki cross-coupling reaction of 3-pyridylboronic pinacol ester with aryl halides

The Suzuki cross-coupling reaction of 3-pyridylboronic pinacol ester with aryl iodides, bromides and chlorides was carried out in DMF/H₂O (3/1, v/v) at 110 °C in the presence of cyclopalladated ferrocenylimine I and K₂CO₃ or CsCO₃ (1.0 equiv.) without the protection of inert gas. By using this method the synthesis of 3-pyridyl biaryl compounds could be readily achieved.     

Synthesis and characterization of new cyclopalladated carbene complexes

Di-μ-chlorobis(2-methyl-2-methoxy-3-t-butylthiopropyl)dipalladium(II) reacted with bis(1,3-diphenyl-2-imidazolidinylidene) to afford a new chlorobridged carbene complex [{PdCl(did)}₂] (did  1,3-diphenyl-2-imidazolidinyl-idenato,2-C,2′-C) in 46.2% yield, which has a cyclopalladated chelate structure involving a Pd—carbene and a Pd—aryl bond; new carbene complexes, [{PdBr(did)}₂], [{Pd(CH₃COO)(did)}₂], [Pd(acac)(did)], and [PdCl(did)Q] (Q  4-MePy, P[OCHMe₂]₃) were also prepared from [{PdCl(did)}₂].     

Syntheses and characterization of novel lanthanide adamantine-dicarboxylate coordination complexes

Hydrothermal reactions of 1,10-phenanthroline (phen), 1,3-adamantanedicarboxylic acid (H₂L) and lanthanide chlorides yielded six compounds: [Ln(L)(HL)(phen)] (Ln=Pr, 1; Nd, 2), [Ln(L)(HL)(phen)(H₂O)] (Sm, 3; Eu, 4), [Tb(L)(HL)(phen)(H₂O)]₂·2H₂O (5), [Er₃(L)₄(OH)(phen)]₂ (6). Compounds 1-4 are structurally featured by one-dimensional polymeric chains; 5 hold binuclear structure constructed from eight-coordinated lanthanide center LnN₂O₆ of distorted bicapped trigonal prism bridged by dicarboxylate ligands; 6 shows that erbium ions are in mono and bicapped trigonal prismatic geometries, respectively, which are further connected by μ₃-OH to give rise to trinuclear structure. Thermogravimetric analyses of 1, 3 and 5 were performed. Fluorescent measurements of 4 and 5 were carried out, respectively.     

Synthesis and characterization of 2-phenylaniline cyclopalladated complexes

Reaction of the dinuclear complex [Pd{κ2-N2′,C1-2-(2′-NH₂C₆H₄)C₆H₄}Cl]₂ (1) with ligands (L = 4-picoline, sym-collidine) gave the six-membered palladacycles [Pd{κ2-N2′,C1-2-(2′-NH₂C₆H₄)C₆H₄}Cl(L)] (2). The complex 1 reacted with AgX (X = CF₃SO₃, BF₄) and bidentate ligands [L–L = phen (phenanthroline), dppe (bis(diphenylphosphino)ethane), bipy(2,2′-bipyridine) and dppp (bis(diphenylphosphino)propane)] giving the mononuclear orthopalladated complexes [Pd{κ2-N2′,C1-2-(2′-NH₂C₆H₄)C₆H₄}(L–L)] (3) [L–L = phen, dppe, bipy and dppp]. These compounds were characterized by physico-chemical methods, and the structure of [Pd{κ2-N2′,C1-2-(2′-NH₂C₆H₄)C₆H₄}Cl(L)] (L = sym-collidine) was determined by single-crystal X-ray analysis.     

N-heterocyclic carbene adducts of cyclopalladated ferrocenylchloropyrimidine: synthesis, structural characterization and application in the Sonogashira reaction

Three N-heterocyclic carbene (NHC) adducts of cyclopalladated ferrocenylchloropyrimidine, 2?C4 [PdCl{[(??⁵-C₅H₅)]Fe[(??⁵-C₅H₃)-N₂C₄H₂-Cl]}(NHCs)] have been prepared by reaction of the chloride-bridged palladacyclic dimer 1 [PdCl{[(??⁵-C₅H₅)]Fe[(??⁵-C₅H₃)-N₂C₄H₂-Cl]}]₂ with the corresponding imidazolium salts. These complexes were characterized by elemental analysis, IR, ESI?CMS and NMR. The use of these complexes as catalysts for the Sonogashira reaction was examined. Complex 4 proved to be an efficient catalyst for the Sonogashira reaction of aryl bromides and some activated aryl chlorides under copper- and amine-free conditions. Typically, using 0.1?C2?mol?% of catalyst in the presence of 1.5 equivalents of CsOAc as base in dimethylacetamide at 120?°C provided coupling products in good yields.     

Generally applicable and efficient oxidative Heck reaction of arylboronic acids with olefins catalyzed by cyclopalladated ferrocenylimine under base- and ligand-free conditions

A mild and efficient method for oxidative Heck-type reaction of arylboronic acids with olefins catalyzed by cyclopalladated ferrocenylimine was developed. The results represent the first examples involving the palladacycle as the catalyst for such couplings. Moreover, the catalytic system could tolerate various functional groups, such as F, Cl, Br, NO₂ and CH₃O, and the substrates could be extended to a wide range of olefins from acrylic esters, α,β-unsaturated ketones to alkenes. Furthermore, the olefination could proceed well under base- and ligand-free conditions and employ oxygen as the environmentally benign oxidant.     

Synthesis and structural characterization of novel pyranoluteolinidin dyes

The synthesis and structural characterization by LC–MS and NMR of novel pyranoluteolinidin derivatives are reported. The compounds result from the reactions between luteolinidin and three different carboxylic acids in wine model-like solutions. The three pigments possess different substituents attached to the D ring (methyl, catechol and dimethylaminophenyl groups) and the same catechol group in the B ring, yielding a wide spectrum of colors from yellow to pink-purple.     

Syntheses and characterization of novel ruthenium complexes based on 1,3-dicyanobenzene

The syntheses and full characterization of novel ruthenium complexes based on 1,3-dicyanobenzene are described. Crystal structures are reported for both [1,3-(cis-RuCl(P(CH₃)₃)₄NC)₂C₆H₄][PF₆]₂ (1cis) and [1,3-(trans-RuCl(dppe)₂NC)₂C₆H₄][H₂PO₄]₂ (3′). Ligand substitution in the homobimetallic complex (3) leads easily to the monometallic analogue, [1,3-(trans-RuCl(dppe)₂NC)C₆H₄(CN)][PF₆] (4). A heterobimetallic complex, [1,3-(trans-RuCl(dppe)₂NC)C₆H₄(CN-FeCp(dppe))][PF₆]₂ (5), of satisfactory purity is also obtained.     

An efficient catalyst for the synthesis of ortho-substituted biaryls by the Suzuki cross-coupling: Triphenylphosphine adduct of cyclopalladated ferrocenylimine

The air and moisture stable triphenylphosphine adduct of cyclopalladated ferrocenylimine 2 has been successfully used in palladium-catalyzed Suzuki cross-coupling for the synthesis of ortho-substituted biaryls in air. In the presence of 0.05 mol% of 2 as catalyst and 3 equivalent of CsF as base in dioxane at 100 °C, ortho-substituted biaryls were synthesized with moderate to high yields in the reactions of 2-methoxy-1-naphthylboronic acid with aryl halides, and 14 new ortho-substituted biaryls were obtained and characterized.     

Syntheses and structural characterization of a monomeric tin(II) diamide and a novel chlorotin(II) amide trimer

We have found that addition of a 2:1 ratio of the bulky ligand Li[N(mesityl)(SiMe(3))] to SnCl(2) yields Sn[N(mesityl)(SiMe(3))](2), which is found by X-ray crystallography to be monomeric in the solid state. Interestingly, the solid state structure of the stannylene exhibits a "minipocket" caused by the parallel arrangement of the phenyl rings. A 1:1 ratio of ligand to SnCl(2) affords the new chlorotin amide [Sn(mu-Cl)[N(mesityl)(SiMe(3))]](3), which adopts a unique trimeric structure in the solid state. The chairlike (Sn-Cl)(3) backbone shown here has not been seen previously in Sn-halide chemistry.     

New optically active pyrazoles: Syntheses and the structural characterization of menthopyrazole analogues

New chiral pyrazoles, (4R,7R)‐4‐methyl‐7‐isopropyl‐3‐phenyl‐ (3‐phenyliso menthopyrazole cis‐1), (4R,7S)‐4‐methyl‐7‐isopropyl‐ (1‐menthopyrazole; trans‐2), (4R,7R)‐4‐isopropyl‐7‐methyl‐ (iso carvomen‐thopyrazole, cis‐3) and (4R,7S)‐4‐isopropyl‐7‐methyl‐4,5,6,7‐tetrahydro‐1H‐indazole (carvomenthopyra‐zole, trans‐3) were prepared. The diastereomeric pairs of these 1–3 were structurally characterized by NMR spectroscopy. The subtle differences of structures of 1–3 should induce the useful effects for a chiral auxiliary or a chiral catalyst.     

Synthesis and structural characterization of novel tetranuclear organotitanoxane derivatives

Synthesis of the novel titanoxane compounds, [(TiCl)(TiOH){(Ti)[μ-(η(5)-C(5)Me(4)SiMe(2)O-κO)](2)(μ-O)}(2)(μ-O)] (4) and [{Ti[μ-(η(5)-C(5)Me(4)SiMe(2)O-κO)](μ-O)}(4)] (5) by controlled reaction of the dinuclear titanium oxo complex [{Ti{μ-(η(5)-C(5)Me(4)SiMe(2)O-κO)}Cl](2)(μ-O)] (1) with 2 equiv of LiOH is reported. Complex 4 is innovative and remarkable. It is one of the rare known examples of tetranuclear stable terminal hydroxo titanium complexes, with an open-chained structure, which coincides with the transient metal monohydroxo proposed in the stepwise pathway employed to justify the formation of the hexanuclear complex [{Ti[μ-(η(5)-C(5)Me(4)SiMe(2)O-κO)](μ-O)}(6)] (3) from 1. (1)H DOSY experiments were used to characterize complex 4. In addition, the structures of compound 5 and of precursor 1 were determined by single-crystal X-ray diffraction studies.