Asymmetric Dihydroxylation of Allylamine Catalyzed by Wool-OsO_4 Complex

A new chiral polymer-metal complex, wool-osmium tetroxide(wool-OsO4) complex was prepared by a very simple method. This complex was found to be able to catalyze the asymmetric dihydroxylation of allylamine to get (R)-(+)-3-amino-l, 2-propanediol. The experimental results showed that OsO4 content in the complex, reaction time, allylamine/OsO4 molar ratio all have great effects on the chemical and optical yields of product. Additionally, wool-OsO4 complex catalyst could be reused without remarkable change in optical catalytic activity.

Thermo- and pH-Responsive Hydrogels Based on N-Isopropylacrylamide and Allylamine Copolymers

The thermo- and pH-responsive hydrogels were synthesized via copolymerization of N-isopropylacrylamide and al-lylamine hydrochloride monomers. The equilibrium swelling of the hydrogels was studied as a function of temperature and pH in aqueous solutions. It was shown that controlled alteration of the hydrogel phase transition temperature can be achieved by changing their composition and pH of the environment. Increase in content of hydrophilic allylamine from 10 to 60 wt% in monomer mixture causes a shift of the phase transition temperature from 35oC to 47oC. Hydrogels with N-isopropylacrylamide/allylamine hydrochloride mass ratio of 3:2 show the highest pH-response. Values of average molecular weight between polymer cross-links, , and Flory parameter, χ, were calculated using temperature dependences of the equilibrium swelling of the synthesized hydrogel.

Optimization of Preparation Process for Allylamine-bacterial Cellulose via Graft Copolymerization by Response Surface Methodology

In order to improve the efficiency of new adsorbent, grafting-allylamine bacterial cellulose（al-BC）, response surface methodology（RSM） was used for the optimization of preparation process. Three factors affecting the yield of grafting reaction are the amount of allylamine, the concentration of ceric ammonium nitrate（CAN） and the concentration of nitric acid. Based on the regression coefficient analysis in the Box-Behnken design, a relationship between the preparation variable and grafting yield was obtained. Square error analysis on main factors, and multi-variable interactions were employed for studying grafting yield. The results show that at the conditions of CAN of 23.00 mmol/L CAN, 0.17 mol/L nitric acid, adding an amount of grafting-allylamine bacterial cellulose of 26.49 mL/L made grafting rate reach maximum of 24.25% at 40℃ after the reaction for 4 h. The experimental results are in good agreement with the calculation values via proposed regression equation, indicating that the equation could be used to nredict and optimizate the preparation of grafting al-BC.

Construction of 3-Azabicyclo[3.1.0]hexane Backbone by the Reaction of Allenes with Allylamines via Tandem Michael Addition and Copper-Mediated Oxidative Carbanion Cyclization

Main observation and conclusion A facile synthetic method for the construction of 3-azabicyclo[3.1.0]hexane in the presence of copper catalyst system was developed.The reaction proceeds through Michael addition of allylamines with allenes followed by copper-mediated intramolecular oxidative carbanion 5-exo-trig radical cyclization,affording potential biologically active 3-azabicyclo[3.1.O]hexane derivatives in moderate to high yields(42%-85%).

A method of active conformation search based on active and inactive analogues, and its application to allylamine antimycotics

A new program ACSBAIA (Active Conformation Search Based on Active and Inactive Analogues ) for determination of the active conformations was developed based on the rationales that specific functional groups of active analogues could reach and interact with the active site of target receptor by means of the change of conformations, but that of inactive analogues could not interact with theactive site owing to conformational restriction. The program consisted of 4 sub-programs: conformation sampling system, active conformation constraint system, inactive conformation exclusion system, and activity prediction system. Pharmacophoric conformation of allylamine antimycotics was studied by this method. Activities of 2 analogues were predicted and tested. The results suggested that the method was scientific and practical. The application of this method was not restricted by the three-dimensional structural knowledge of target receptor. In the absence of structural information about the receptor, the method was particularly applicable.

Development of Coatings Marine Antifouling Based on Perfluorinated Surfactants Synthesis and Physicochemical Study

The fight against dirt settling on the hulls of ships and more generally on all underwater structures is more than 2000 years. The need for effective antifouling paints, which prevents the establishment and growth of marine organisms on submerged structures, is universally recognized. In this work, we synthesize two perfluorinated surfactants from simple monomers. After describing the reactions, we discuss the different analyzes of the proton nuclear magnetic resonance (1H NMR), the fluorine nuclear magnetic resonance (NMR I9F), gel permeation chromatography (GPC) and the light scattering (LS) at a fixed angle 90. The glass transition temperature of the two surfactants diethylallylphosphonate and allylamine are obtained by Differential Scanning Calorimetry (DSC). Antifouling paint properties were followed by exposure of the plates to the marine environment by visual observation.

Amine-containing film deposited in pulsed dielectric barrier discharge at a high pressure and its cell adsorption behaviours

With monomer allylamine, amine-containing functional films were prepared in alternative current pulsed dielectric barrier discharge （DBD） at a high pressure. This paper analyses in detail the film properties and structures, such as hydrophilicity, compounds and microstructures as well as amine density by the water contact angle, Fourier transform infrared spectroscopy, atomic force microscopy, and ultraviolet-visible measurement. The influence of discharge param- eters, in particular applied power, on amine density was investigated. As an application the cell adsorption behaviours on plasma polymerization films was performed in-vitro. The results show that at a high pressure pulsed DBD plasma can polymerize films with sufficient amine group on surface, through which the very efficient cell adsorption behaviours was demonstrated, and the high rate of cell proliferation was visualized.

Effect of synthesis variables of plasma synthesized polymers on growth of HepG2 cells

Low pressure plasma polymer films were synthesized using pyrrole and allylamine monomers and adding iodine was used(or not)for the reaction in both cases.They were polymerized on glass substrates under the same reaction conditions.Polymerization of allylamine was also studied at different operating powers.These thin polymer films were used as culture surfaces for HepG2 cells,a cell line derived from a human hepatoma.The proliferation,differentiation and two-dimensional propagation until obtaining monolayer of the cells was studied on the different synthetized films and correlations were established between the conditions of synthesis,the physicochemical characteristics obtained and the performance as substrates for the cellular growth.

Roughness Control of Layer-by-Layer and Alternative Spray Films from Congo Red and PAH via Laser Light Irradiation

Films from congo red (CR) alternated with poly(allylamine hydrochloride), PAH, were prepared by layer-by-layer and alternative spray techniques. In order to investigate the change of roughness induced by laser light irradiation (532 nm), both kinds of films were characterized by using UV-visible spectroscopy and atomic force microscopy (AFM). At dif- ferent irradiation times, layer-by-layer, LbL, films showed small changes in the roughness and irregular behavior, whereas spray films exhibited higher and a regular decreasing of roughness with increasing irradiation time. The higher roughness of spray films as compared with the LbL ones was attributed to different formation mechanisms of the films. The decreasing of the roughness as a function of the irradiation time (exhibited by the spray films) was associated to surface relaxation due to the interplay between photoisomerization of congo red dye and the heating of the sample during the laser light irradiation. The results suggested that the alternative spray technique is the best choose to control of roughness of the films by using light irradiation.

Synthesis and characterization of a new organic-inorganic hybrid polyphosphazene polymer

A new organic-inorganic hybrid polyphosphazene polymer was synthesized via sequential nucleophilic substitution using allylamine and phenol. The polymer was characterized by FTIR, 1H-NMR, and 31P-NMR spectra. The thermal properties were studied by DSC and TGA. It was found that the polymer has good thermal stability. Char yields of the polymer reaches to 48.6% at 800°C. The high char yield makes it possible in theory for the polymer to be used as flame retardant. By cross linking, the thermal stability of the polymer could be improved further.

Mesomorphous structure change by tail chain number in ionic liquid crystalline complexes of linear polymer and amphiphiles

Three polymer-amphiphile complexes were prepared by combining poly（allylamine hydrochloride）（PAH） with the potassium salt of mono-,di-,and trisubstituted benzoic acid dendrons（4-octyloxybenzoic acid,3,5-dioctyloxybenzoic acid,and 3,4,5- trioctyloxybenzoic acid）.The solid structure and properties were monitored with FT-IR,XRD,TG,DSC,and polarized optical microscope（POM）.Difference in the tail chain number of the dendritic amphiphile induced two different mesomorphous structures： lamella for the mono-,disubstituted dendron containing complexes and hexagonal column for the trisubstituted dendron containing complexes.These corresponded to the ionic thermotropic liquid crystal SmA andΦ_h phases,respectively.This finding is significant for design of functional nanostructures based on the ionic complexation of polymers and amphiphiles.

Radical-mediated hydroalkylation of 2-vinylpyrrolidine derivatives: a versatile entry into indolizidine alkaloids

A concise route for the preparation of two simple optically pure indolizidin-5-ones has been developed.The key chain elongation process was achieved using a triethylborane/catechol mediated hydroalkylation of Boc-protected 2-vinylpyrrolidines.By using complementary strategies,these two bicyclic lactams can be alkylated with complete control of the stereochemistry at C(5)and their conversion to a variety of indolizidine alkaloids such as coniceine,indolizidine 209D and 167B,5-epi-indolizidine 249A and monomorine has been reported in the literature.

Fabrication of Covalently Linked PAH/PVS Layer-by-layer Assembled Multilayers via a Post-photochemical Cross-linking Strategy

A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly（allylamine hydrochloride）（PAH）/poly（vinylsulfonic acid sodium salt）（PVS） multilayers. Con- ventional polyelectrolyte multilayers of PAH/PVS are usually fabricated through electrostatic layer-by-layer（LbL） assembly, resulting in poor stability, especially in basic solutions, which leads to the urgent demand for converting weak electrostatic interactions into covalent bonds to enhance the stability of the multilayers. This stability problem has been ultimately addressed by post-infiltrating a photosensitive cross-linking agent, 4,4＇-diazostilbene-2,2＇- disulfonie acid disodium salt（DAS）, into the LbL assembled films to initiate the photochemical reaction to cross-link the multilayers. The obviously improved stability of the photo-cross-linked multilayers was demonstrated through experiments with basic solution treatments. Compared to the complete decomposition of uncross-linked multilayers in basic solution, over 74.4% of the covalently cross-linked multilayers were retained under the same conditions, even after a longer duration of basic solution treatment.

Dual photoredox and cobalt catalysis enpowers site-selective allylic amination

The development of a highly efficient,selective and atom-economical method for the construction of allylic amines are a challenge in green synthetic chemistry.In a recent work published in Nature Catalysis,Lei,Qi,and coworkers reported that the combination of a photoredox catalyst and cobaloxime catalyst enables site-selective allylic amination of various olefins with secondary alkyl amines,affording the valuable tertiary aliphatic allylamines,without the need for external oxidants.