纳米铝粉促进羰基化合物水相烯丙基化反应

氮气保护条件下,纳米铝在0.1 N NH₄Cl溶液中,能有效地促进羰基化合物与烯丙基溴进行Barbier-Grignard型烯丙基化反应,得到相应高烯丙醇。芳香族醛或酮的烯丙基化产率较高,而脂肪族羰基化合物反应产率低,反应产率受羰基空间位阻影响大,在同样条件下,邻羟基羰基化合物烯丙基化产物主要是赤式-邻二醇。     

One-Pot Synthesis of 1,4-Dihydropyridine and Polyhydroquinoline Derivatives via L-Proline Catalyzed Hantzsch Multicomponent Reaction under Ultrasound Irradiation

L‐Proline efficiently catalyzed the multi‐component Hantzsch reaction in EtOH at 60°C under ultrasound irradiation to afford the corresponding 1,4‐dihydropyridine and polyhydroquinoline derivatives in high yields. This method offers the advantages of neutral and mild reaction conditions, high to excellent yields of the products and simple workup.     

Catalyst‐Free Reaction in Water: Synthesis of Functionalized Tetrahydroindole Derivatives via Three‐Component Domino Reaction

An environmentally benign and efficient method has been developed for the synthesis of functionalized tetrahydroindole derivatives in aqueous media under catalyst‐free conditions, by simply combining a phenylglyoxal monohydrate, an enaminone, and a barbituric acid. The advantages of this method are that it is catalyst free, has an easy workup, provides good yields, and uses water as solvent, which make this procedure facile and practical.     

Revealing Triple‐Shape Memory Effect by Polymer Bilayers

Bilayer polymers that consist of two epoxy dual‐shape memory polymers of well‐separated glass transition temperatures have been synthesized. These bilayer epoxy samples exhibit a triple‐shape memory effect (TSME) with shape fixities tailorable by changing the ratio between the two layers. The triple‐shape fixities of the bilayer epoxy polymers can be explained by the balance of stress between the two layers. Based on this work, it is believed that the following three molecular design criterions should be considered in designing triple‐shape memory polymers with optimum TSME: 1) well‐separated thermal transitions, 2) a strong interface, and 3) an appropriate balance of moduli and relative ratios between the layers (or microphases).

     

Chemoselective Synthesis of Novel Heterocyclic [3.3.3]Propellane Derivatives via a One‐pot Three‐component Reaction

A highly chemoselective method for the synthesis of heterocyclic [3.3.3]propellane derivatives was developed via sequential three‐component reactions of acenaphthenequinone, malononitrile/cyanoacetate and a variety of 1,3‐dicarbonyl compounds under mild conditions in ethanol. A plausible mechanism for this type of reaction was proposed. The value of this method was highlighted by its high selectivity, simple procedures, and good yields.     

Nano–Mn‐[4‐nitrophenyl‐salicylaldimine‐methyl pyranopyrazole]Cl2 as a new nanostructured Schiff base complex and catalyst for the synthesis of hexahydroquinolines

By the reaction of 4‐nitrobenzaldehyde with ethyl acetoacetate, malononitrile and hydrazine hydrate, pyranopyrazole derivative as an active biological compound was synthsized and then reacted with salicylaldehyde and MnCl₂.4H₂O to afford nano‐Mn‐[4‐nitrophenyl‐salicylaldimine‐methyl pyranopyrazole]Cl₂ (nano‐[Mn‐4NSMP]Cl₂) for the first time. The produced Schiff base complex with nanostructured was fully characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG) and scanning electron microscope (SEM) and used it as an efficient catalyst for the preparation of hexahydroquinolines.     

A Multicomponent,Catalyst‐free,One‐Pot Synthesis of Functionalized 1,4‐Dihydroquinolines and Their Antimicrobial Studies

An atom‐efficient, catalyst‐free, and environmentally friendly approach towards the synthesis of substituted 1,4‐dihydroquinolines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j ) through a one‐pot multicomponent reaction involving resorcinol, aromatic aldehyde, acetoacetanilide, and ammonium acetate has been developed. The reactions were carried out under both conventional and microwave irradiation conditions. In general, improvement in rate and yield were observed when reactions were carried out under microwave irradiation compared with classical conditions. Most of the new compounds possessed moderate to significant antibacterial and antifungal activities.     

Phase Transition Behaviors of Self‐Oscillating Polymer and Nano‐Gel Particles

Summary: Self‐oscillating polymers and nano‐gel particles consisting of N‐isopropylacrylamide and the ruthenium catalyst of the Belousov‐Zhabotinsky reaction have been prepared. In order to clarify the crosslinking effect on the self‐oscillating behavior, the phase transition behaviors were investigated by measuring the transmittance and the fluorescence intensity of the polymer solution and the gel bead suspension. Cooperative effects due to crosslinking will play an important role for the design of nanoactuators.

Chemical structure of poly(NIPAAm‐co‐Ru(bpy)₃).     

UV‐Induced Tetrazole‐Thiol Reaction for Polymer Conjugation and Surface Functionalization

A UV‐induced 1,3‐dipolar nucleophilic addition of tetrazoles to thiols is described. Under UV irradiation the reaction proceeds rapidly at room temperature, with high yields, without a catalyst, and in both polar protic and aprotic solvents, including water. This UV‐induced tetrazole‐thiol reaction was successfully applied for the synthesis of small molecules, protein modification, and rapid and facile polymer–polymer conjugation. The reaction has also been demonstrated for the formation of micropatterns by site‐selective surface functionalization. Superhydrophobic–hydrophilic micropatterns were successfully created by sequential modifications of a tetrazole‐modified porous polymer surface with hydrophobic and hydrophilic thiols. A biotin‐functionalized surface could be fabricated in aqueous solutions under long‐wavelength UV irradiation.     

Synthsis of 4‐Piperidones via Multicomponent Double Mannich Reaction Catalyzed by I2

A multicomponent double Mannich reaction of amines, aldehydes and ketones was efficiently catalyzed by molecular iodine, producing a series of 4‐piperidones in a stereoselective way. A variety of amines, aldehydes and ketones were tolerated in this tandem process, including those with labile functinal groups. Further investigation of the reaction between alkyl‐imines and ketones showed that imines from amines and ketones were formed in situ and isomerized to enamine in the presence of molecular iodine to accelerate the corresponding Mannich addition.     

Stimuli‐Responsive Hybrid Coatings of Polyelectrolyte Multilayers and Nano‐Patterned Polymer Brushes

A new type of polymeric hybrid coating is created by layer‐by‐layer deposition of polyelectrolyte multilayers (PEM) onto nano‐patterned polymer brushes (NPB). The PEM is a hydrogen‐bonded multilayer consisting of poly(acrylic acid) and poly(acrylamide) and the NPB is derived from a surface reactive rod‐coil block copolymer, polystyrene‐block‐poly[3‐(triethoxysilyl)propylisocyanate]. The thickness of the PEM coating is optimized with respect to the height of the NPB mounds, to yield PEM/NPB hybrid coatings with unique nano‐embossed or nano‐porous structures that can be interchangeable by heating and moisture annealing. The hybrid coating is patternable by the micro‐contact printing method. The results demonstrate that the combination of surface‐bound, hydrophobic NPB layer with hydrophilic PEM films at the nanoscopic level offers a new organic hybrid coating with novel surface properties.

     

Temperature/pH‐Sensitive Hydrogels Prepared from Pluronic Copolymers End‐Capped with Carboxylic Acid Groups via an Oligolactide Spacer

The Pluronic F127 triblock copolymer was end‐capped by carboxyl groups using a degradable oligolactide as a spacer to confer pH‐ and thermo‐sensitive properties. With increasing chain length of the oligolactide, the temperature‐dependent sol‐gel transition curve was significantly shifted to higher concentration with concomitant narrowing of the gelation temperature range. Carboxylic acid end‐capped Pluronic also exhibited a peculiar pH‐dependent sol‐gel transition behavior. At 37 °C, sharp gel‐to‐sol and sol‐to‐gel transitions were observed around pH = 4.8 and 8.2, respectively. The pH‐dependent phase transition was caused by introduction of carboxylic acid groups at the ends of Pluronic F127.

     

A Sensitive and Renewable Chlortoluron Molecularly Imprinted Polymer Sensor Based on the Gate‐Controlled Catalytic Electrooxidation of H2O2 on Magnetic Nano‐NiO

A new sensor was fabricated by MIP synthesized on the surface of magnetic nickel(II) oxide (NiO) nanoparticles which based on the oxidation current change of H₂O₂. Chlortoluron was selected as template which can be detected indirectly by the decrease of the H₂O₂ oxidation current on the NiO nanoparticle‐modified GCE caused by the blocking access after rebinding. A high sensitivity was obtained because of the high catalytic effect of NiO nanoparticles on H₂O₂ oxidation. Chlortoluron was determined from 1.0×10^?8/L to 1.0×10^?4 mol/L, with a detection limit of 2.4×10^?9 mol/L. The proposed method combines the high sensitivity of the catalytic effect and the high selectivity of the MIP technique. Water samples were assayed using the MIP sensor, and recoveries of 96.9 % to 104.7 % were obtained.     

Synthesis,characterization and application of nano‐CoAl2O4 as an efficient catalyst in the preparation of hexahydroquinolines

In this work, nano‐CoAl₂O₄ was prepared and characterized by FT‐IR, energy dispersive X‐ray analysis (EDX), X‐ray diffraction patterns (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). Nano‐CoAl₂O₄ was applied for the synthesis of hexahydroquinoline derivatives by the condensation reaction between ethyl acetoacetate, dimedone and various aldehydes. These reactions were carried out at 80 °C under solvent‐free conditions.     

Synthesis of Pseudo‐Peptides Containing a Quinazolinone Skeleton via Ugi Four‐Component Reaction

A simple and efficient synthesis of quinazolinone pseudo‐peptide derivatives based on a new 3‐amino‐1,2,3,4‐tetrahydro‐4‐oxoquinazoline‐2‐carboxylic acid via Ugi four‐component reaction has been developed. This reaction was conducted under mild conditions with a broad scope of substrates.     

Temperature‐Induced Transformation from Large Compound Vesicles to Worm‐like Aggregates by ABC Triblock Copolymer

Two triblock polymers, tetraaniline‐block‐poly(N‐isopropyl acrylamide)‐block‐poly(hydroxyethyl acrylate) (TA‐b‐PNIPAM‐b‐PHEA) and TA‐b‐PHEA‐b‐PNIPAM, were synthesized with unambiguous structure by a two step method. The difference of these two diblock polymers is the connection order of carboxyl group to block, e.g., carboxyl group to PNIPAM block for PNIPAM‐b‐PHEA and to PHEA block for PHEA‐b‐PNIPAM. Secondly, block tetraaniline was linked to the diblock polymer through amidation to yield the corresponding triblock copolymer. Both of them have almost the identical chemical compositions. The only difference is the connection order of each block in the triblock polymers. When they were self‐assembled at 45°C in a suitable solution, both of their aggregates have spherical shape with slight defects on their surface with the average diameter of about 400 nm. However, when their aggregate dispersion was cooled down to 20°C, only TA‐b‐PHEA‐b‐PNIPAM's morphology changed, forming worm‐like aggregates with the diameter of about 100–200 nm transformed from spherical aggregates. Both amphiphilic property and position of each block in this triblock copolymer are very essential for this morphology transformation. Since the worm‐like aggregates presented here by our group have hollow structure inside, its controlled release properties for doxorubicin were evaluated. Drug release experiment indicated that along with the temperature changes, the rearrangement of the intermediate layer structure caused morphology change in aggregate, thus accelerating the speed of drug release.     

基于可控相转变温度热敏高分子的人IgG酶联荧光免疫分析

以温度敏感高分子聚N－异丙基丙烯酰胺－丙烯酰胺[P(NIP-AA)]作为载体,建立了酶联荧光免疫分析人IgG的新方法。AA摩尔含量为8％的高分子P(NIP-AA)其临界溶解温度为37 °C。竞争型免疫测定中,被固定的IgG和标准溶液（或样品）在33 °C均相条件下竞争性地与辣根过氧化物酶标记抗体反应,升高温度分离出高分子免疫复合物,沉淀重新溶解后通过偶联过氧化氢与对羟基苯乙酸的荧光反应进行定量,线性范围为100-1000 ng/mL,检测限为2.0 ng/mL。方法灵敏、快速操作简便,且提高了免疫反应效率。此外,灵敏度与用传统微孔板做载体相似,但测定时间更快（从100-120分钟减少到30分钟）。该法用于测定人血清中IgG的含量,结果满意。     

Gold Nanoparticles Functionalized by a Dextran‐Based pH‐ and Temperature‐Sensitive Polymer

A dextran‐based dual‐sensitive polymer is employed to endow gold nanoparticles with stability and pH‐ and temperature‐sensitivity. The dual‐sensitive polymer is prepared by RAFT polymerization of N‐isopropylacrylamide from trithiocarbonate groups linked to dextran and succinoylation of dextran after polymerization. The functionalized nanoparticles show excellent stability under various conditions and can be stored in powder‐form. UV and DLS measurements confirm that the temperature‐induced optical changes and aggregation behaviors of the particles are strongly dependent on pH.

     

Poly(amidoamine) Conjugates Containing Doxorubicin Bound via an Acid‐Sensitive Linker

Poly(amidoamine)s with amino pendant groups were prepared by hydrogen‐transfer polyaddition of primary and secondary amines to bis‐acrylamines. Dansyl cadaverine (DC) doxorubicin (Dox) were bound to the polymers via a cis‐aconityl spacer to give conjugates containing 3 µg of DC per mg of polymer and 28 to 35 µg of Dox per mg of polymer. Release of DC and Dox at physiological and acidic pH varied from 0 to 35% over 48 h and was pH dependent. Although the ISA1Dox conjugate (IC₅₀ = 6 µg Dox · mL^?1) presented similar toxicity as the parent polymer without Dox, ISA23Dox showed increased toxicity (IC₅₀ = 10 µg Dox · mL^?1). These results suggest that ISA23Dox is able to release biologically active Dox in vitro and that this conjugate might be suitable for further development.