New ferrocene-derived hydroxymethylphosphines: FcP(CH2OH)2 [Fc=(η-C5H5)Fe(η-C5H4)] and the dppf analogue 1,1-Fc[P(CH2OH)2]2 [Fc=Fe(η-C5H4)2]

Reactions of the ferrocene-phosphines FcPH₂ and 1,1^′-Fc^′(PH₂)₂ with excess formaldehyde gives the new hydroxymethylphosphines FcP(CH₂OH)₂ 1 and 1,1^′-Fc^′[P(CH₂OH)₂]₂ 2, respectively. Phosphine 1 is an air-stable crystalline solid, whereas 2 is isolated as an oil. Reaction of 1 with H₂O₂, S₈ or Se gives the chalcogenide derivatives FcP(E)(CH₂OH)₂ (E=O, S or Se), whilst reaction of 2 with S₈ gives 1,1^′-Fc^′[P(S)(CH₂OH)₂]₂, which were fully characterised. Phosphine 1 was also characterised by an X-ray crystal structure determination.     

Syndiotactically enriched 1,2-selective polymerization of 1,3-butadiene initiated by iron catalysts based on a new class of donors

A series of phosphoryl (PO) contained compounds: triethylphosphate (a), diethylphenylphosphate (b), ethyldiphenylphosphate (c) triarylphosphates (d and h-m), triphenylphosphine oxide (e), phenyl diphenylphosphinate (f) and diphenyl phenylphosphonate (g) have been prepared. Iron catalysts, which are generated in situ by mixing the compounds with Fe(2-EHA)₃ and AlⁱBu₃ in hexane, are tested for butadiene polymerization at 50 °C. Phosphates donated catalysts have been, unprecedently, found to conduct extremely high syndiotactically (pentad, rrrr = 46.1-94.5%) enriched 1,2-selective (1,2-structure content = 56.2-94.3%) polymerization of butadiene. Introduction of electron withdrawing substituents on phenyl rings oftriphenylphosphate (k-m) remarkably promotes catalytic activity, while bulky substituent isopropyl at 2-position (h) has beneficial influence on regioselectivity. Employment of e, f or g as donor, results in a suppressed monomer conversion, accompanied by deteriorated 1,2-regioselectivity. The effects of polymerization conditions such as reaction temperature, types of cocatalysts and polymerization medium are also investigated by using catalyst system with tri(2,4-difluorophenyl)phosphate (m) as donor. Highly tolerance to polymerization temperature up to 80 °C is observed for the first time in the iron-based catalyst.     

Dual chemosensing properties of new ferrocene-based receptors towards fluoride and copper(II) ions

The new ferrocene based receptors N-[4-ferrocenyl-2-methyl-4-oxobut-1-enyl]-N′-phenylthiourea (1), N-[4-ferrocenyl-2-methyl-4-oxobut-1-enyl]-N′-[4-nitrophenyl]thiourea (2) were synthesized and characterized. Fluorescence titrations of receptors 1 and 2 with various transition metal ions showed selective response to Cu²⁺ ions and the emission intensities quenched significantly. Electrochemical titrations with anions revealed that receptors 1 and 2 sensed the F⁻ anion in high selectivity with a cathodic shift of 100 mV.     

Preparation,surface-active properties and acid decomposition profiles of a new “soap” bearing a 1,3-dioxolane ring

New soap-type surfactants bearing a 1,3-dioxolane ring were prepared in good yields by the acid-catalyzed condensation of 1-O-alkylglycerols (alkyl: decyl, dodecyl, tetradecyl, heptadecyl, octadecyl, orcis-9-octadecenyl) with oxocarboxylic acid esters, followed by alkaline hydrolysis without any expensive reagent and special equipment. These surfactants were soluble in alkaline water at room temperature. Their critical micelle concentrations were much smaller than that of sodium dodecanoate. An alkaline solution of the octadecyl homologue was nonfoaming, but the other homologues, including thecis-9-octadecenyl derivative, showed high foaming ability in alkaline solutions. The structural effect of these compounds on the area per molecule at the surface is also discussed. Because these surfactants contain a 1,3-dioxolane ring, they can be utilized as a new acid-decomposable type of cleavable surfactant. At pH 1, they decompose almost completely into nonsurface-active species after 80 min.     

Silica gel-promoted new one-pot procedure for the synthesis of 1,3-oxathiolan-5-one

A highly selective two-component silica gel-promoted synthesis of 1,3-oxathiolan-5-one derivatives in N,N-Dimethylformamide (DMF) is presented. The reaction was carried out using aromatic aldehyde and mercaptoacetic acid in the presence of silica gel in DMF with heating. The reactions were worked up by separating the silica gel and recovering the solid product after adding water in excellent yields without any chromatographic purification. Structures of the compounds were satisfactorily confirmed by ¹H NMR and LCMS spectral analysis.     

Oxidative Dehydrogenation of a C4 Raffinate‐2 towards 1,3‐Butadiene in a Two‐Zone Fluidized Bed

The oxidative dehydrogenation of a C4 raffinate‐2 consisting of n‐butane, 1‐butene, and 2‐butene was conducted in a two‐zone fluidized bed reactor using a Mo‐V‐MgO catalyst. This study reports the influence of the operating conditions temperature, hydrocarbon inlet height, and oxygen/hydrocarbon molar ratio on the product distribution, in particular on the formation of 1,3‐butadiene. Axial concentration profiles were measured to elucidate the reaction sequence in the fluidized bed.     

The influence of lateral substituents on the phase behavior of side-chain liquid crystalline polysiloxanes containing trans-2,5-disubstituted-1,3-dioxane based mesogenic side groups

The synthesis and characterization of the polysiloxanes containingtrans-2,5-disubstituted-1,3-dioxane-based mesogenic side groups were described in this present study. Among three polysiloxanes containing three methylene units in their spacers, one without the lateral substituent exhibited two enantiotropic smectic phases while the other two polymers with a lateral methyl- or methoxy-substituent displayed an enantiotropic nematic phase. For polymers containing a longer spacer length (n 4), those without lateral substituent presented two enantiotropic smectic phases while the others containing a lateral substituent showed only an enantiotropic smectic A phase. The lateral substitution exerted a strong effect on the mesomorphic properties of the synthesized polymers.     

Anionic polymerization of 1,3‐cyclohexadiene: Addition of poly(1,3‐cyclohexadienyl)lithium to fullerene‐C60

The addition of poly(1,3‐cyclohexadiene) (PCHD) carbanion to fullerene‐C₆₀ (C₆₀) was examined using poly(1,3‐cyclohexadienyl)lithium (PCHDLi), PCHDLi/1,4‐diazabicyclo[2,2,2]octane (DABCO), and PCHDLi/N,N,N′,N′‐tetramethylethylenediamine (TMEDA). The reactivity of PCHD carbanions was in the order of PCHDLi > PCHDLi/DABCO > PCHDLi/TMEDA, regardless of the polymer main chain structure. PCHDLi, PCHDLi/DABCO, and PCHDLi/TMEDA in toluene formed σ‐structures, σ‐ and π‐structures, and π‐structures, respectively. The degree of localization on the terminal carbanion was a main factor for control of this addition reaction. In addition, all 1,2‐cyclohexadiene (1,2‐CHD) unit sequences contributed to preventing the addition reaction. That is, large steric hindrance of the polymer main chain was another important factor to control the addition reaction. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Pyridazino-1,3a,6a-Triazapentalenes as Versatile Fluorescent Probes: Impact of Their Post-Functionalization and Application for Cellular Imaging

Pyridazino-1,3a,6a-triazapentalenes (PyTAP) are compact fused 6/5/5 tricyclic scaffolds which exhibit promising fluorescent properties. Chemically stable, they can be post-functionalized using standard Pd-catalyzed cross-coupling chemistry. Several original PyTAP bearing additional unsaturated substituents in positions 2 and 8 were synthetized and their spectroscopic properties analyzed. They have been successfully tested as fluorescent probes for cellular imaging.     

硼酸催化合成N,N-二甲基-N′-月桂酰基-1,3-丙二胺及其同系物

以不同碳链长度的饱和脂肪酸、N,N-二甲基-1,3-丙二胺(DMAPA)为原料合成了N,N-二甲基-N′-月桂酰基-1,3-丙二胺(C12DMAPA)及其同系物。通过改变反应温度、调节酸胺的摩尔比和加入的硼酸的比例,探索反应的优化条件。在酰胺化反应中,最优条件为,n(脂肪酸)∶n(DMAPA)=1∶1.8,在110℃反应6～8h,加入催化量的硼酸(5mol%),收率为78%～90%。产物用IR表征鉴定。     

胡椒环合成的研究进展

胡椒环作为一种重要的有机合成中间体,广泛地用于香料,杀虫剂,医药等精细化学品的制备。文章综述了胡椒环的合成方法的新进展,包括非质子极性溶剂使用,相转移催化剂催化反应,无溶剂条件下以及分子筛催化下的反应。     

Living polymerization of 1,3-butadiene by a Ziegler-Natta type catalyst composed of iron(III) 2-ethylhexanoate, triisobutylaluminum and diethyl phosphite

Living characteristics of facilely prepared Ziegler-Natta type catalyst system consisting of iron(III) 2-ethylhexanoate, triisobutylaluminum and diethyl phosphite have been found in the polymerization of 1,3-butadiene in hexane at 40 °C. The characteristics have been well demonstrated by: a first-order kinetics with respect to monomer conversion, a narrow molecular weight distribution (M_w/M_n = 1.48-1.52) of polybutadiene in the entire range of polymerization conversion and a good linearity between M_n and the yield of polymer. Feasible post-polymerization of 1,3-butadiene and block co-polymerization of 1,3-butadiene and isoprene further support the living natures of the catalyst bestowed with. The current catalyst system is highly active (yield > 80%, 35 min), providing polybutadiene with 1,2, cis-1,4 and trans-1,4 units about 44.0%, 51.0% and 5.0%, respectively.     

1,3-二羟基丙酮的合成与应用研究进展

1,3-二羟基丙酮作为重要的化工医药中间体,广泛应用于化工、医药、化妆品和食品领域。主要综述了1,3-二羟基丙酮的合成方法,包括化学合成法和微生物合成法,并介绍了其在化工与医药领域的最新应用进展。     

微生物法生产1,3-丙二醇过程的代谢工程研究进展

代谢工程在微生物发酵法生产化工产品的过程中扮演着越来越重要的角色. 本研究以生物法生产1,3-丙二醇所涉及的关键酶、代谢途径及其改造为考察对象,系统综述了微生物法生产1,3-丙二醇所涉及的代谢工程技术、最新应用情况及其进展,并展望了未来的发展趋势.     

Preparation and properties of sulfonate salt-type cleavable surfactants with a 1,3-dioxane ring

A series of di-anionic cleavable surfactants were prepared by the condensation of aldehydes with 2,2-bis(hydroxymethyl)-1,3-propanediol, followed by reaction with 1,3-propanesultone in the presence of sodium hydride. Surfactant 5a had a different¹H nuclear magnetic resonance spectrum in D₂O than products 5b−d. This was rationalized by its different conformation, which originates from the self-coiling of its alkyl chain. The critical micelle concentrations, Krafft points and hydrolysis properties of these surfactants were determined.     

Experimental study of the structure of a rich premixed 1,3-butadiene/CH4/O2/Ar flame

The structure of a laminar rich premixed 1,3-butadiene/CH₄/O₂/Ar flame has been investigated, 1,3-butadiene, methane, oxygen, and argon mole fractions being 0.033, 0.2073, 0.3315, and 0.4280, respectively, for an equivalence ratio of 1.80. The flame has been stabilized on a burner at a pressure of 6.7 kPa. The concentration profiles of stable species have been measured by gas chromatography after sampling with a quartz probe. The quantified species include carbon monoxide and dioxide, methane, oxygen, hydrogen, ethane, ethylene, acetylene, propyne, allene, propene, cyclopropane, 1,3-butadiene, butenes, 1-butyne, vinylacetylene, diacetylene, C₅ compounds, benzene, and toluene. The temperature distribution in the flame has also been measured. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 6, pp. 89–95, November–December, 2006.     

Efficient synthesis of 2-hydroxyalkyl alkanedithioates from 1,3-diketones,CS2, and epoxides

An efficient synthesis of 2-hydroxyalkyl alkanedithioates via a one-pot reaction between 1,3-diketones, carbon disulfide, and substituted oxiranes in the presence of catalytic amount of triethylamine in tetrahydrofuran is described.     

Development of a new azido-oxazoline monomer for the preparation of amphiphilic graft copolymers by combination of cationic ring-opening polymerization and click chemistry

A new monomer (2-(5-azidopentyl)-2-oxazoline) bearing an azido group was synthesized. The cationic ring-opening copolymerization of this monomer with 2-methyl-2-oxazoline resulted in a well-defined linear polymer backbone with pendant azido groups. Alkynyl-poly(d,l-lactide) was grafted onto the azido groups of poly(oxazoline) via a Huisgen 1,3-dipolar cycloaddition reaction to give a novel amphiphilic graft copolymer [poly(2-methyl-2-oxazoline-co-2-pentyl-2-oxazoline)-g-poly(d,l-lactide)] (P[(MeOx-co-PentOx)-g-LA]). Different graft copolymers were prepared with PLA of different lengths. Preliminary results of the self-association of this copolymer in water indicated the formation of nanoparticles, which suggests this copolymer may have applications as vehicles for drug delivery.     

Kinetics of polyesterification: modelling and simulation of unsaturated polyester synthesis involving 2-methyl-1,3-propanediol

The kinetics of the individual key reactions involved in the formation of unsaturated polyester resins have been studied using the very reactive glycol, 2-methyl-1,3-propanediol (MPD). This diol has been reacted in turn with maleic anhydride (MA), phthalic anhydride (PA) and isophthalic acid (IA) under isothermal conditions in the temperature range 180-210 °C and the kinetic constants for the following reactions have been obtained MA+MPD, PA+MPD, IA+MPD, MA+PA+MPD and MA+IA+MPD. The relative reactivities of MPD with MA and PA measured by monitoring the loss of carboxyl groups at 180 and 200 °C were found to be 2.26 and 1.70, respectively. At 200 °C PA is more reactive than IA (ratio approximately 1.31) in homopolyesterification. In the copolyesterifications involving PA and IA where cross catalysis can occur, the PA reacted approximately 1.25 times faster than IA at 200 °C. The differences in reactivity might be expected to have a significant effect on the coreactant sequence lengths in prepolymers formed by the concurrent reaction of PA, IA and MPD particularly at low conversions thus on the final properties of the cured resins in which they are employed. The properties of the products are not examined in this paper.     

Preparation,characterization and biodegradable characteristics of poly(1,3-trimethylene carbonate-co-glycolide)

Poly(1,3-trimethylene carbonate-co-glycolide) (PGCA) has been synthesized by ring-opening polymerization of 1,3-trimethylene carbonate (CA) and glycolide (GA) with stannous octoate as catalyst. The copolymers were characterized by ¹H nuclear magnetic resonance (NMR), ¹³C NMR and differential scanning calorimetry. Water content and static contact angle of distilled water on the polymer surface were used to evaluate the hydrophobicity of the copolymers. There was no apparent difference in hydrophobicities of copolymers containing up to 30 mol% GA. The biodegradation of PGCA was conducted in phosphate buffer solution at 37°C and in rats. The results indicated that the degradation rates of PGCA were higher than that of PCA and depended on the GA fraction in the copolymers. Furthermore, degradation occurred in the bulk when the GA content exceeded 20 mol%. With less GA units the degradation became a surface reaction both in vitro and in vivo. These properties of PGCA may be useful in protein delivery systems.