((3-(3-硅胶丙基)硫基)丙基)硫酸酯作为可回收催化剂用于合成4,4'-芳亚甲基-双(1H-吡唑-5-醇)(英文)

Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4'-alkylmethylene-bis(3-methyl-5-pyrazolones) in 74-90% yields. The heterogeneous catalyst was recycled and used in eleven runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without losing catalytic activity.     

Silica-bonded S-sulfonic acid: an efficient and recyclable solid acid catalyst for the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols)

Silica-bonded S-sulfonic acid (SBSSA) is employed as a recyclable catalyst for the condensation reaction of aromatic aldehydes with 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4′-alkylmethylene-bis(3-methyl-5-pyrazolones) in 75-90% yields.     

Asymmetric α-amination of 4-substituted pyrazolones catalyzed by a chiral Gd(OTf)3/N,N'-dioxide complex: highly enantioselective synthesis of 4-amino-5-pyrazolone derivatives

The asymmetric α-amination of 4-substituted pyrazolones with azodicarboxylates was investigated for the first time, employing an N,N'-dioxide gadolinium(III) complex as the catalyst. The novel transformations exhibited high yield, and 4-amino-5-pyrazolone derivatives bearing a chiral quaternary center were obtained in excellent yields (up to 99%) and enantioselectivities (90%-97% ee) for a broad scope of 5-pyrazolones by using 1 mol % or only 0.05 mol % of catalyst.     

Cross‐Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate‐Determining Deprotonation of Bound Hydrazine

Reported here is the Pd‐catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate‐limiting deprotonation of a hydrazine‐bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.     

丁二烯-丙烯腈共聚物碳-碳双键的选择性加氢

丁二烯－丙烯腈共聚物碳－碳双键的选择性加氢张邦华,王光,周庆业,郝广杰,宋谋道,张莹（南开大学高分子化学研究所,天津,３０００７１）关键词丁二烯－丙烯腈共聚物,氯化三苯基膦铑,均相催化,选择性加氢通过催化加氢对不饱和高聚物进行化学改性是提高大分子的物...     

Rapid defunctionalization of carbonyl group to methylene with polymethylhydrosiloxane-B(C(6)F(5))(3)

The polymethylhydrosiloxane-B(C(6)F(5))(3) combination is found to be a versatile carbonyl defunctionalization system under mild and rapid conditions. For the first time, B(C(6)F(5))(3) has been used as a nonconventional Lewis acid catalyst to activate PMHS. Aromatic and aliphatic carbonyl compounds were effectively reduced to give the corresponding alkanes in high yields.     

Flavin-catalyzed generation of diimide: an environmentally friendly method for the aerobic hydrogenation of olefins

The first green and practical method for "aerobic hydrogenation" involving the use of hydrazine and an organocatalyst is described. Olefins can be hydrogenated by treatment with hydrazine in the presence of a 5-ethyl-3-methyllumiflavinium perchlorate (FlEt+.ClO4-) catalyst under O2 atmosphere to give the corresponding hydrogenated products in excellent yields along with environmentally benign water and molecular nitrogen as the only waste products.     

2,2-二(4-羟基-3-氨基)苯基丙烷的合成

在乙醇介质中,以Fe(OH)3／C为催化剂,用80％水合肼将2,2-二(4-羟基-3-硝基)苯基丙烷还原为2,2-二(4-羟基-3-氨基)苯基丙烷。产率99．0％,纯度98．5％。考察了10种金属离子对催化剂活性的影响,结果发现Pb^2 会引起催化剂中毒;Mg^2 ,Cu^2 和Zn^2 钝化了催化剂的催化活性;Ba^2 和Cr^3 不影响催化剂的活性;Al^3 ,Ni^2 ,Ti^3 和Ti^4 能活化催化剂,使反应速度加快,但它们单独使用时无催化活性。     

二氧化硅负载的聚-4-硫杂-6-二苯膦己基硅氧烷钯(0)配合物的合成与催化性能

聚-4-硫杂-6-二苯膦己基硅氧烷与氯化钯作用后经水合肼还原,合成了二氧化硅负载的硫-膦混合双齿钯(0)配合物.该配合物可以有效地催化芳(烯)基卤化物与烯烃、炔烃、Grignard试剂的交叉偶联反应,并可回收多次利用,活性基本不变.     

Enantioselective synthesis of chiral 4H-pyran derivatives through [3+3] tandem reaction over a squaramide catalyst

An efficient [3+3] tandem reaction between 1-phenyl-3-methyl-5-pyrazolones and 2-(1-alkynyl)-2-alken-1-ones over a tertiary amine–squaramide catalyst is described. The pyran fused pyrazolone derivatives were successfully obtained in 53–88% yields and with 62–84% ee by this synthetic methodology. This methodology involves easily accessible starting material, mild condition, satisfied yields and ee values. Additionally, when enynes were used as the substrates for the [3+3] cascade reaction, isomerized target products could be obtained directly.     

多面体低聚八氨基苯基硅倍半氧烷合成方法改进及其表征

以八硝基苯基硅倍半氧烷(ONPS)为原料, 5% Pd/C 和FeCl₃ 为催化剂, 水合肼为还原剂, 在四氢呋喃溶液中反应 1 h 合成了八氨基苯基硅倍半氧烷(OAPS). 相比文献中已有的其它合成方法, 该方法合成过程简单且稳定, 催化效率高、产率高、周期短. 通过FTIR, ¹H NMR, GPC 对产物进行了表征, 证明了硝基已完全转化. 通过催化剂的控制, 分离出ONPS 向OAPS 转化过程中的一种含有羟胺和二羟胺基团的中间体. 分析了OAPS 合成机理, 提出了ONPS 和水合肼的反应历程. 认为ONPS 中的硝基先经过2 电子转移转化为二羟胺化合物, 然后经过脱水加氢生成羟胺化合物, 最后再经过脱水加氢生成OAPS; 在有ONPS 存在的情况下, 水合肼主要转化为氮气和氢气, 待ONPS 完全转化为OAPS 后, 水合肼转化为氮气和氨气.     

Conversion of Some 2(3H)‐Furanones into Pyrrolinotriazine and Oxazolopyrimidine Derivatives

2(3H)‐Furanones 1 were utilized for the construction of pyrrolinotriazine and oxazolopyrimidine derivatives 4 and 9 . Thus, 1 reacted with glycine in ethanol at 70°C to give the acids 2 , which were cyclized into the pyrrolin‐5‐one derivatives 3 by the action of HCl/AcOH. The later compounds 3 were also obtained by refluxing the furanones 1 with glycine in glacial AcOH for 10 h. The carboxy functionality in 3 was used for the construction of a triazinone ring by treatment with thionyl chloride followed by refluxing the acid chloride with hydrazine in ethanol. The conversion of the furanones 1 into the oxazolopyrimidine derivatives 9 involved the following steps: (i) ring opening of the lactone ring with hydrazine hydrate to give the acid hydrazides 5 , (ii) conversion of the hydrazides 5 into the corresponding acyl azides 6 by action of NaNO2/AcOH, (iv) base‐catalyzed decomposition of the azides in the presence of glycine, (v) ring closure of the urea derivatives 7 into the pyrimidine derivatives 8 , and finally (vi) condensing 8 with benzaldehyde in the presence of NaOAc/AcOH mixture.     

Sodium dodecyl benzene sulfonate-catalyzed reaction for aromatic aldehydes with 1-phenyl-3-methyl-5-pyrazolone in aqueous media

Sodium dodecyl benzene sulfonate was successfully used for the tandem Knoevenagel-Michael reaction of aromatic aldehydes with 1-phenyl-3-methyl-5-pyrazolone in water to synthesis of 4, 4′-arkylmethylene-bis(1-phenyl-3-methyl-5-pyrazolones) under mild reaction conditions. Efficient catalytic activity and high selectivity of the catalyst contributed to colloidal particle formation in water. The shape and size of the colloidal aggregates were confirmed by optical microscopy and dynamic light scattering.     

双(对-氨基苯基)-2,3,7,8,12,13,17,18-八甲基卟啉及其金属衍生物的合成与表征

从3-甲基-2,4-戊二酮出发,经多步反应合成了3,3′,4,4′-四-甲基-2,2′-二吡咯基甲烷(TMDPM),改进了合成TMDPM的脱羧反应.研究了TMDPM与对-硝基苯甲醛反应合成meso-5,15-双-苯基-卟啉反应,发现对-甲基苯磺酸是卟啉原合成的良好催化剂,2,3-二-氯-5,6二氰基-1,4-苯醌是将卟啉原转化为卟啉的良好氧化剂;硝基卟啉经SnCl₂还原成氨基卟啉后,用固-液抽提进行氨基卟啉的纯化,得到了5,15-双(对-硝基苯基)-2,3,7,8,12,13,17,18-八甲基卟啉、5,15-双(对-氨基苯基)-2,3,7,8,12,13,17,18-八甲基卟啉及其金属衍生物,并表征了其结构     

Enhanced reactivity in a heterogeneous oxido-peroxido molybdenum(VI) complex of salicylidene 2-picoloyl hydrazone in catalytic epoxidation of olefins

A molybdenum(VI) oxido-diperoxido complex of salicylidene 2-picoloyl hydrazine (sal-phz) was synthesized and successfully grafted onto chloro-functionalised Fe₃O₄ nanoparticles. The resulting heterogeneous and magnetically recoverable nanoscale catalyst MoO₃(sal-phz)/Fe₃O₄ was characterized by physicochemical and spectroscopic techniques. The activity of this heterogeneous catalyst for the oxidation of olefins to corresponding epoxides was efficiently increased by increasing the reaction temperature up to 95 °C. The nanocatalyst proved to be efficient for the selective epoxidation of a variety of alkenes using t-BuOOH with high conversion and selectivity. Leaching and recycling tests showed that the nanocatalyst can be reused at least six times without significant decrease in efficiency.     

(Butadiene)metallocene/B(C6F5)3 pathway to catalyst systems for stereoselective methyl methacrylate polymerization: evidence for an anion dependent metallocene catalyzed polymerization process

The ansa-zirconocene dichlorides [Me(2)Si(C(5)H(4))(3-R-C(5)H(3))]ZrCl(2) 7a-e (R = H, CH(3), cyclohexyl, -CHMe(2), -CMe(3)) were reacted with butadiene-magnesium to yield the respective (eta(4)-butadiene)metallocenes 17a-e. The chiral examples give a mixture of two s-cis and two s-trans diastereomers. The strong Lewis acid B(C(6)F(5))(3) adds selectively to a terminal butadiene carbon atom to yield the (butadiene)metallocene/B(C(6)F(5))(3) betaine complexes 18a-e. Initially, the formation of the Z-18 isomers is preferred. These consecutively rearrange to the thermodynamically favored isomers E-18. The dipolar systems 18 are active single component metallocene catalysts for the stereospecific polymerization of methyl methacrylate. With increasing steric bulk of the attached single alkyl substituent an increasingly isotactic poly(methyl methacrylate) is obtained. A similar trend is observed in the methyl methacrylate polymerization at the [Me(2)Si(C(5)H(4))(3-R-C(5)H(3))]ZrCH(3)(+) catalysts (9a-e) that were conventionally prepared by methyl abstraction from the corresponding ansa-zirconocene dimethyl complexes by treatment with B(C(6)F(5))(3). A comparison of the poly(methyl methacrylates) obtained at these two series of catalysts has revealed substantial differences in stereoselectivity that probably originate from an influence of the respective counteranions. An initial reactive intermediate of methyl methacrylate addition to the dipolar single component metallocene catalyst E-18a was experimentally observed and characterized by NMR spectroscopy at 253 K. The subsequently formed series of [PMMA-C(4)H(6)(-)B(C(6)F(5))(3)](-) anion oligomers (at the catalyst 18c) was monitored (after quenching) and characterized by electrospray mass spectrometry.     

Potentiometric,spectrometric, thermal and conductimetric studies on some 3-phenyl-4-(arylazo)-5-pyrazolones and their complexes with divalent cobalt metal ion

3-phenyl-4-arylazo-5-pyrazolones (I-IV) have been synthesized and characterized by elemental, infrared (IR), ultraviolet and visible spectra (UV-Vis), proton nuclear magnetic resonance (1H NMR) and Mass spectra. It has been proved that these compounds exhibit a keto-enol tautomerism in solution. The donor character of the substituent increases the enol form. The ionization constants of the investigated ligands have been determined potentiometrically and found to decrease in the order OCH(3)(IV)>CH(3)(III)>H(I)>Cl(II). The Co(II) complexes of the investigated 3-phenyl-4-arylazo-5-pyrazolones (I-IV) have been prepared and characterized by elemental and thermal analyses as well as by IR, UV-Vis, electronic transition, potentiometric, conductimetric and magnetic measurements. The data suggest octahedral geometry for Co(II) (1:1) complexes and tetrahedral for Co(II) (2:3) complexes.     

Catalytic Enantioselective Intermolecular Benzylic C(sp3)−H Amination

A practical general method for asymmetric intermolecular benzylic C(sp³)?H amination has been developed by combining the pentafluorobenzyl sulfamate PfbsNH₂ with the chiral rhodium(II) catalyst Rh₂(S‐tfptad)₄. Various substrates can be used as limiting components and converted to benzylic amines with excellent yields and high levels of enantioselectivity. Additional key features for the reaction are the low catalyst loading and the ability to remove the Pfbs group under mild conditions to give NH‐free benzylic amines.     

C2-symmetric bis(oxazolinato)lanthanide catalysts for enantioselective intramolecular hydroamination/cyclization

C(2)-symmetric bis(oxazolinato)lanthanide complexes of the type [(4R,5S)-Ph(2)Box]La[N(TMS)(2)](2), [(4S,5R)-Ar(2)Box]La[N(TMS)(2)](2), and [(4S)-Ph-5,5-Me(2)Box]La[N(TMS)(2)](2) (Box = 2,2'-bis(2-oxazoline)methylenyl; Ar = 4-tert-butylphenyl, 1-naphthyl; TMS = SiMe(3)) serve as precatalysts for the efficient enantioselective intramolecular hydroamination/cyclization of aminoalkenes and aminodienes. These new catalyst systems are conveniently generated in situ from the known metal precursors Ln[N(TMS)(2)](3) or Ln[CH(TMS)(2)](3) (Ln = La, Nd, Sm, Y, Lu) and 1.2 equiv of commercially available or readily prepared bis(oxazoline) ligands such as (4R,5S)-Ph(2)BoxH, (4S,5R)-Ar(2)BoxH, and (4S)-Ph-5,5-Me(2)BoxH. The X-ray crystal structure of [(4S)-(t)BuBox]Lu[CH(TMS)(2)](2) provides insight into the structure of the in situ generated precatalyst species. Lanthanides having the largest ionic radii exhibit the highest turnover frequencies as well as enantioselectivities. Reaction rates maximize near 1:1 BoxH:Ln ratio (ligand acceleration); however, increasing the ratio to 2:1 BoxH:Ln decreases the reaction rate, while affording enantiomeric excesses similar to the 1:1 BoxH:Ln case. A screening study of bis(oxazoline) ligands reveals that aryl stereodirecting groups at the oxazoline ring 4 position and additional substitution (geminal dimethyl or aryl) at the 5 position are crucial for high turnover frequencies and good enantioselectivities. The optimized precatalyst, in situ generated [(4R,5S)-Ph(2)Box]La[N(TMS)(2)](2), exhibits good rates and enantioselectivities, comparable to or greater than those achieved with chiral C(1)-symmetric organolanthanocene catalysts, even for poorly responsive substrates (up to 67% ee at 23 degrees C). Kinetic studies reveal that hydroamination rates are zero order in [amine substrate] and first order in [catalyst], implicating the same general mechanism for organolanthanide-catalyzed hydroamination/cyclizations (intramolecular turnover-limiting olefin insertion followed by the rapid protonolysis of an Ln-C bond by amine substrate) and implying that the active catalytic species is monomeric.     

丁二烯-b-甲基丙烯酸甲酯共聚物中C＝C的选择性催化加氢

以氯化三苯基膦铑为催化剂,对丁二烯-b-甲基丙烯酸甲酯共聚物的催化加氢反应进行了研究,用NMR、FTIR、动态粘弹谱和化学分析法对加氢产物进行了表征。证明RhCl[P(C₆H₅)₃]₃可有效地使共聚物中的C＝C加氢,且具有很高的选择性,未加氢的双键含量小于0.71%.