一锅法从卟啉配体合成μ-氧代四苯基双核铁卟啉

A novel method for synthesis of substituted μ-oxo-bis [tetraphenyl porphyrinatoiron] compounds ([TRPPFe]2O) based on the reaction among free base porphyrins (TRPPH2), FeSO4·7H2O and H2O in one pot was proposed and investigated. Four kinds of [TRPPFe]2O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, infrared spectra and UV-vis spectroscopy. The reaction conditions, including the effect of different iron salts on the formation of [TRPPFe]2O, the reaction time between FeSO4·7H2O and TRPPH2, the molar ratio of FeSO4·7H2O/TRPPH2 as well as the volume ratio of H2O/DMF, were investigated. The [TRPPFe]2O yield of 93%-98% could be obtained under the following optimal conditions: the reaction time of FeSO4·7H2O with TRPPH2 was about 10h, the molar ratio of FeSO4·7H2O/TRPPH2 about 5:1, and the volume ratio of H2O/DMF exceeded 2:1. Further research indicated that only TRPPFeCl were formed once FeSO4·7H2O was replaced by FeCl2·4H2O, the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe]2O, suggesting that halogen ions should be avoided in this novel synthetic method.     

Synthesis of pyrazolo[4′,3′:5,6]pyrido[1,2-a]benzimidazole derivatives and study of their fluorescence properties

Synthesis of pyrazolo[4′,3′ :-5,6′pyrido]1,2-a benzimidazoles was achieved by the condensation of 1-chloro-2-formyl-3-methyl pyrido[1,2-a]benzimidazole-4-carbonitrile and 1-chloro-3-methyl pyrido[1,2-a]benzimidazole-2,4-dicarbonitrile with hydrazine hydrate and phenyl hydrazine. The fluorescence properties of the resulting compounds were studied. Some of the compounds when applied on polyester fibres as fluorescent brighteners gave excellent results.     

无溶剂微波辅助一锅法合成吡喃并[2,3-c]吡唑衍生物

绿色、高效、简便的催化多组分一锅法反应符合当前所倡导的"绿色"化学理念,是当今有机化学的研究热点.通过在无溶剂微波辅助条件下,使用廉价易得的KF/A1203催化吡唑啉酮、芳香醛和丙二腈的多组分"一锅法"反应,合成了一系列吡喃并[2,3-c]吡唑衍生物,反应时间为5-10 min,产率为85％-98％.标题化合物的结构经...     

Four‐Electron Electrocyclic Ring‐Opening/Intermolecular [4+2] Cycloadditions of α‐Hydroxycyclobutenones: Stereoselective Synthesis of Multiple Substituted δ‐Lactams

A four‐electron electrocyclic ring‐opening/intermolecular [4+2] cycloaddition of α‐hydroxycyclobutenones is reported. The reaction represents the first example for the intermolecular cycloaddition of the extensively studied enol‐ketene intermediate, and provides a new synthetic route to multiply substituted δ‐lactams in high stereoselectivity.

     

Thermal Intramolecular [2+2] Cycloaddition: Synthesis of 3‐Azabicyclo[3.1.1]heptanes from Morita–Baylis–Hillman Adduct‐Derived 4,4‐Diaryl‐1,3‐dienes

Various 3‐azabicyclo[3.1.1]heptane derivatives were synthesized from Morita–Baylis–Hillman adduct‐derived 1,3‐dienes bearing a 4,4‐diaryl moiety through a thermal intramolecular [2+2] cycloaddition approach. By using the same approach, bicyclo[3.1.1]heptane, 3‐azabicyclo[3.2.0]heptane, and 3‐oxabicyclo[3.1.1]heptane derivatives could also be synthesized. A structurally similar dimethylallyl derivative underwent an intramolecular ene reaction to afford the pyrrolidine derivative.

     

Gold‐Catalyzed 5‐ and 6‐exo‐dig Selective Cyclizations of Alkynyl Silyl Enol Ethers: Efficient Method for [3+2] and [4+2] Annulations onto α,β‐Enones

An efficient method for the annulation of five‐ and six‐membered rings onto α,β‐enones is described via gold‐catalyzed 5‐ and 6‐exo‐dig selective cyclizations of alkynyl silyl enol ethers.     

Regioselective Synthesis of Functionalized Pyrroles via Gold(I)‐Catalyzed [3+2] Cycloaddition of Stabilized Vinyl Diazo Derivatives and Nitriles

The reaction of nitriles with alkenyldiazo compounds in the presence of gold catalysts provides functionalized pyrrole derivatives in moderate to high yields. This formal [3+2] cyclization reaction takes place with complete regioselectivity. The observed regiochemical outcome suggests the attack of the nitrile to the terminal position of the alkenylgold carbenoid (vinylogous reactivity). A broad range of nitriles (including those bearing functional groups) is compatible with this cyclization reaction.     

Polymerization of lactides and lactones. III. Ring-opening polymerization of DL-lactide by the (η3-C3H5)2Sm(μ2-Cl)2(μ3-Cl)2Mg(tmed)(μ2-Cl)Mg(tmed) complex

Ring-opening polymerization of DL -lactide (LA) has been initiated with the (η³-C₃H₅)₂Sm(μ₂-Cl)₂(μ₃-Cl)₂Mg(tmed)(η₂-Cl)Mg(tmed) complex both in bulk and solution. The effects of reaction conditions, such as reaction time, reaction temperature, and monomer/initiator molar ratio on the polymerization has been discussed. The results showed that (η³-C₃H₅)₂Sm(μ₂-Cl)₂(μ₃-Cl)₂Mg(tmed)(μ₂-Cl)Mg(tmed) was more effective for the polymerization of LA, and high molecular weight of polylactide was obtained by this initiator. The solvent affected the polymerization significantly. The polymerization mechanism was in agreement with the coordination mechanism. The polymer was characterized by FTIR, ¹H-NMR, and DSC. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2857–2862, 1999     

Gold(I)‐Catalyzed Cascade for Synthesis of Pyrrolo[1,2‐a:2′,1′‐c]‐/Pyrido[2,1‐c]pyrrolo[1,2‐a]quinoxalinones

An efficient and convenient method was developed for the one‐pot construction of the complex polycyclic heterocycles pyrrolo[1,2‐a:2′,1′‐c]‐/pyrido[2,1‐c]pyrrolo[1,2‐a]quinoxalinones from two simple starting materials via a gold(I)‐catalyzed domino reaction. This strategy presents an atom economical and environmentally friendly transformation, in which two new C N bonds and one new C C bond are formed in a one‐pot reaction process.     

Precisely Controlling Preparation of Ceria‐Stabilized Zirconia Microspheres of ~100 μm by External Gelation

Ceria‐stabilized zirconia (CSZ) microspheres of ~100 μm were prepared by external gelation process. The inner diameter of nozzle was 0.2 mm. The key process parameters including broth pH value, Zr concentration, flow rate, and vibration frequency were optimized for precise control of the diameter. The optimum parameters were found to be flow rate of 11.08 mL/min, Zr concentration of 0.72 mol/L, and vibration frequency of 2650 Hz. CSZ microspheres with an average diameter of 103.1 μm and standard deviation of 4.4 were prepared under these conditions. CSZ microspheres showed good monodispersity, good sphericity, and high density.     

[3+2] Cycloaddition of Propargylamines and α‐Acylketene Dithioacetals: A Synthetic Strategy for Highly Substituted Pyrroles

A new [3+2] cycloaddition strategy for the direct synthesis of highly substituted pyrroles from the readily available α‐acylketene dithioacetals (or related substrates) and commercially available propargylamines under mild metal‐free conditions has been developed. In this reaction, the acyl group plays a critical role in driving the conjugate addition of propargylamine and further cyclization to give pyrroles. Furthermore, the wide scope was confirmed by the preparation of 1,2,3,4‐tetrasubstituted pyrroles (60–70% yields) via a formal 1,2‐acyl migrating [3+2] cycloaddition pathway with N‐methylprop‐2‐yn‐1‐amine as the secondary amine component.