Synthesis of 4,5-fused tricyclic quinolines via an acid-promoted intramolecular Friedel–Crafts allenylation of aniline derivatives

A novel method for synthesizing 4,5-fused tricyclic quinoline derivatives based on an acid-promoted intramolecular Friedel–Crafts allenylation of anilines. Using aryl group-substituted propargyl alcohol derivatives with a meta-substituted N-Boc aniline unit as substrates, a four-step reaction sequence involving an acid-promoted intramolecular Friedel–Crafts allenylation of anilines, an acid-promoted intramolecular C–N bond formation, deprotection of the Boc group, and air oxidation proceeded in a single pot, producing the corresponding 4,5-fused tricyclic quinoline derivatives in 31–84% yield.     

有机化学进展(2011~2012)

本文综述了中国大陆地区有机化学研究人员2011至2012年两年内在合成方法学、有机合成化学、元素有机化学以及天然产物化学等领域获得的重要成果。文章中共引用参考文献355篇,其中110多篇手性金属配合物和有机小分子催化的不对称反应、金属催化的碳氢键活化等合成方法学论文和30余篇氟有机化学论文基本来源于德国《应用化学》(国际版)和《美国化学杂志》。本文汇集了中国有机化学家两年中合成的150多个具有生物活性和化学结构多样性的天然产物,其中不乏具有高度挑战性的复杂天然分子。在近两年中中国有机化学家从陆地和海洋的生物体内发现各种不同类型新天然产物90多个。     

Synthesis of highly substituted quinolines via heterocyclization of fluorinated acetylenephosphonates with ortho-aminoaryl ketones

A synthetic route to a series of 4-alkyl- or arylquinolines, bearing in 2- and 3-position fluorinated and phosphonate functions at the same time, is reported for the first time. These compounds are synthesized via regioselective heterocyclization of XCF₂-alkynylphosphonates (X=F, Cl, Br, H, CF₃) with ortho-aminoaryl ketones (R=CH₃, CF₃, Ph) in the presence of K₂CO₃ or Li₂CO₃/TMEDA as mediators. 2-Fluoro- and 3-phosphorus-containing 4-Me, 4-CF₃ or 4-Ph quinolines are obtained in good to excellent yields. The influence of substituents in the aromatic ketone, the XCF₂-group in the alkyne as well as mediators and the reaction medium on the reactivity and specificity of the reaction is also investigated.     

Divergent synthesis of 6H-isoindolo[2,1-a]indol-6-ones and indenoindolones: an investigation of Pd-catalyzed isocyanide insertion

A novel Pd-catalyzed intramolecular cyclization via tert-butyl isocyanide insertion from 2-(2-bromophenyl)-1H-indoles has been developed, which demonstrates the utility of isocyanides in C–N or C–C bond construction. Treatment of 2-(2-bromophenyl)-1H-indoles with tert-butyl isocyanide affords 6H-isoindolo[2,1-a]indol-6-ones with high efficiency. However, N-methyl or N-Boc protected 2-(2-bromophenyl)-1H-indoles gives indenoindolones in excellent yields under the same condition, which reveals that under the described situation, isocyanides insertion for the formation of C–N bonds is prior to that of C–C bonds.     

Synthesis of a furano abietane cyano enone—A new scaffold for biological exploration

A six step synthesis of furano abietane cyano enone 12 is described, in which the key step is a palladium-catalyzed intramolecular Heck reaction of bromo 3-phenoxyacrylate 17, prepared from enone phenol 13 in high yield.     

Determination of synthetic polycyclic musks in water by microwave-assisted headspace solid-phase microextraction and gas chromatography-mass spectrometry

This paper describes a rapid and solvent-free method, microwave-assisted headspace solid-phase microextraction (MA-HS-SPME), for the extraction of six commonly used synthetic polycyclic musks: galaxolide (HHCB), tonalide (AHTN), celestolide (ADBI), traseolide (ATII), cashmeran (DPMI) and phantolide (AHMI) from water samples prior to their determination using gas chromatography-mass spectrometry (GC-MS). The effects of various extraction parameters for the quantitative extraction of these analytes by MA-HS-SPME were systematically investigated and optimized. The analytes in a 20-mL water sample (in a 40-mL sample-vial containing 4 g of NaCl) were efficiently extracted by a polydimethylsiloxane-divinylbenzene (PDMS-DVB) fiber placed in the headspace when the system was microwave irradiated at 180 W for less than 4 min. The limits of detection (LODs) ranged from 0.05 to 0.1 ng/L, and the limits of quantification (LOQs) were less than 0.2 ng/L. A preliminary analysis of wastewater samples revealed that HHCB and AHTN were the two most commonly detected synthetic polycyclic musks; using a standard addition method, their concentration were determined to range from 1.2 to 37.3 ng/L with relative standard deviation (RSD) ranging from 2 to 6%. The results obtained using this approach are better than those from the conventional oil-bath HS-SPME.     

Selective recognition of ovalbumin using a molecularly imprinted polymer

Micro-contact imprinting has been used to form thin-film molecular imprints of ovalbumin (OVA) in polymers supported on glass slides. Thermocalorimetric data was used to optimise the choice of functional monomer and cross-linker to maximise selectivity and minimise non-specific recognition.A polymer comprising polyethyleneglycol 400 dimethacrylate (95 vol.%) and methacrylic acid (5 vol.%) showed both maximum recognition for OVA when made as a molecularly imprinted polymer (MIP), and minimal recognition when made as a non-imprinted, i.e. control polymer. OVA rebinding to the molecularly imprinted polymer, from a buffered 2 µM OVA solution, was 1.55 × 10^{− 11} mol cm^{− 2}, while the control polymer showed 10-fold less re-binding, i.e. 0.154 × 10^{− 11} mol cm^{− 2}.Experiments in which human serum albumin (HSA), conalbumin, ovomucoid or lysozyme, were re-bound to the polymers, either as single proteins or in competition with OVA, showed them to have low affinity for the polymer formulation used. Of the competing proteins examined, in non-competitive binding experiments, HSA showed the greatest affinity 0.45 × 10^{− 11} mol cm^{− 2} for the OVA imprinted polymer. In two protein competition experiments, i.e. with OVA and a competing protein present at equal concentrations (2 µM), OVA binding to the OVA imprinted polymer was in all cases significantly greater than that of the competitor.     

Environmental biodegradation of synthetic polymers I. Test methodologies and procedures

Biodegradation of synthetic polymers is an important property that is used in many applications. Evaluation of the extent of biodegradation has used different methods in recent years. For each environmental compartment, different approaches have to be made in order to obtain valuable data on biodegradability.This review describes validated and accepted methods based on standardized biodegradation tests, analytical tests, enzymatic tests or tests of physical properties to evaluate the biodegradability of synthetic polymers for different types of environmental compartments (e.g., soil, compost or aqueous media).Part II of this review will subsequently report on the environmental biodegradation of different groups of synthetic polymers.     

高分子共混物中氢键的作用Ⅱ.氢键对高分子共混物性能的影响以及引入方法

高分子共混物中氢键的存在能促进共混组分具有更好的可混和性.因此,研究高分子共混物中的氢键对高分子的共混改性具有重要的理论和实用价值.本文是<高分子共混物中氢键的Ⅰ.氢键的特征描述以及影响因素>的下篇,将继续介绍高分子共混物中氢键的作用,主要包括氢键对高分子共混物性能的影响以及主要的引入氢键的方法.特别地,本文通过将高分子共混物分为合成高分子与合成高分子共混物,合成高分子与天然高分子共混物以及合成高分子与其它物质共混物,总结了氢键存在对共混物性能的影响.     

Convenient synthesis of substituted benzo[e][1,2,4]- or [d][1,2,6]oxadiazepines,benzo[f][1,3,5]triazocines from N-aryliminoesters

We report herein a short and efficient synthesis of benz[e][1,2,4]- or [d][1,2,6]oxadiazepines and benzo[f][1,3,5]triazocines from easily prepared N-aryl iminoesters. The strategy involves a bis-nucleophile reagent (hydroxylamine or guanidine) that promotes a one-step ring closure from the starting functionalized iminoesters.