A New Approach to α—Bromochalcones

α-Bromo benzolymethylene triphenylphosphorane 3 has been synthesized by the reaction of benzoylmethylene triphenylphosphorane 1 with N-bromosuccinimide in the yield of 87% and can react with aromatic aldehydes 4 to give α-bromochalcones 5 in good yields.     

An Overview of Molecular Packing Mode in Two‐Dimensional Organic Nanomaterials via Supramolecular Assembly

Two‐dimensional (2D) organic nanomaterials are attracting increasing research interest and expected to be the ideal candidate for future‐ proofed flexible electronics and biotechnologies. Owing to the complex molecular structures and multiple intermolecular interactions in organic systems, deeper understanding of rational molecular design and assembly principles is urgently required. In this review, a collection of molecular packing mode in the 2D organic nanomaterials via supramolecular assembly is presented, so as to help explicit the relationship among molecular structures, supramolecular interactions and molecular packing motifs in 2D assembly systems. We also provide a rational and accessible schematic model to demonstrate several typical kinds of molecular packing motifs for the prediction of the 2D morphology.     

TEOS-MTES基SiO2溶胶微结构的SAXS研究

正硅酸乙酯(TEOS)为前驱体,在碱性条件下制备含有无定形SiO2颗粒的溶胶,以甲基三乙氧基硅烷(MTES)在酸性条件下获得聚甲基硅氧链,二者混合后应用同步辐射X射线进行混合溶胶的SAXS散射强度测定,计算了溶胶的平均回转半径、平均粒径、两相界面层厚度、散射体体积分数、两相间比表面积等参数,辅以光子相关光谱法(PCS)和透射电子显微镜(TEM)观测溶胶粒度,证实SiO2颗粒被MTES混合物连接成族团.实验发现所测混合溶胶样品均表现出对Porod定理的负偏离,说明溶胶中颗粒与溶剂之间存在很明显的两相间界面层.     

Synthesis of new 1,3-bis（phenylethynyl）disilazanes

Three new 1,3-bis(phenylethynyl)disilazanes were synthesized from the reaction of 1,3-dichlorodisilazanes with (phenylethy- nyl)lithium,and characterized by infrared (IR) spectra,nuclear magnetic resonance (NMR) and mass spectrometry (MS).     

Adenanthusone,a New Ursane Type Nortriterpenoid from Isodon adenanthus

A new ursane‐type nortriterpenoid, adenanthusone (=(11α,12α)‐4‐demethyl‐11,12‐epoxy‐3,13‐dihydroxy‐2‐oxoursa‐3,20(30)‐diene‐28‐oic acid γ‐lactone; 1 ) was isolated from Isodon adenanthus. Its structure was determined by NMR spectra and X‐ray crystallographic diffraction analysis. The biogenetic implication of the nortriterpene is discussed.     

Synthesis, Structure and Conductivity of the New Charge-transfer Salt (ET)_2(CH_2=CH-CH_2-SO_3)·H_2O

ET is one of the most famous electron-donor molecules, which forms charge-transfer complexes (abbr. CT-complexes) with various types of counterions. These complexes have received intense attention because a wide range of physical properties such as conductivity and superconductivity1, ferromagnetism2-4 and nonlinear optical properties5 was found in these materials. Although the majority of the ET-based CT-complexes were prepared by combining with inorganic counterions, CT-complexes with o…     

New Approach to Synthesis of 6,7—Dimethoxyisatin

A new approach to synthesis of 6,7-dimethoxyisatin is reported.2-nitro-3,4-dimethoxy mandelonitrile in glacial acetic acid was treated with the solution of stannous chloride in hydrochloric acid to give 6,7-dimethoxyisatin in a high yield.     

Furostanol saponins with inhibitory action against COX-2 production from Tupistra chinensis rhizomes

Two furostanol saponins were obtained from the n-butanol fraction of methanol extract from Tupistra chinensis rhizomes,a folk medicine of Shennongjia Forest District of Hubei Province.Their structures were determined as (25S)-26-O-(β-D-glucopyranosyl)- furost-1β,3β,22α,26-tetrol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (1) and (25R)- 26-O-(β-D-glucopyranosyl)-furost-1β,3β22α,26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glu- copyranoside (2),on basis of chemical and spectroscopic evidences.1 and 2 displayed marked inhibitory action towards COX-2 production in macrophages of the rat abdomen induced by LPS at 20μg/mL.     

Pharmacokinetic detection of penicillin excreted in urine using a totally internally reflected resonance light scattering technique with cetyltrimethylammonium bromide

A quantitative analysis method for penicillins including ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO) is proposed that makes use of the totally internally reflected resonance light scattering (TIR-RLS) signal from the penicillin at the H₂O/CCl₄ interface in the presence of cetyltrimethylammonium bromide (CTMAB), and enables the pharmacokinetics of penicillin taken orally and excreted through urine to be monitored. Penicillin is coadsorbed with CTMAB at the H₂O/CCl₄ interface in neutral solution, resulting in the formation of ion associates that display greatly enhanced TIR-RLS signals (maximum at 368–372 nm). This enhanced TIR-RLS intensity was found to be proportional to the penicillin concentration over the range 0.2×10^–6 to 2.2×10^–6 mol L^–1, with limits of determination (3) of 5.0×10^–8 to 7.0×10^–8 mol L^–1. Pharmacokinetics studies performed using the present method show that the excretion of orally-taken ampicillin through urine has a half-time of 1.05 h and an excremental quantum over 8 h of 49.3%, respectively.     

Synthesis of Enantiomerically Pure Ferrocenes from Glycofuranosyl-cyclopentadienes,synthetic equivalents of (alkoxyalkyl)fulvenes

Cyclopentadienyl C-glycosides (= glycosyl-cyclopentadienes) have been prepared as latent fulvenes. Their reaction with nucleophiles leads to cyclopentadienes substituted with (protected) alditol moieties and, hence, to enantiomerically pure metallocenes. Treatment of 1 with cyclopentadienyl anion gave the epimeric glycosyl-cyclopentadienes 6 / 7 (Scheme 1). Each epimer consisted of a ca. 1:1 mixture of the 1, 3-and 1, 4-cyclopentadienes a and b , respectively, which were separated by prep. HPLC. Slow regioisomerisation occurred at room temperature. Diels-Alder addition of N-phenylmaleimide to 6a / b ca. 3:7 at room temperature yielded three ‘endo’-adducts, i.e., a disubstituted alkene ( 8 or 9 , 25%) and the trisubstituted alkenes 10 (45%) and 11 (13%). The structure of 10 was established by X-ray analysis. Reduction of 6 / 7 (after isolation or in situ) with LiAlH₄ gave the cyclopentadienylmannitols 12a / b (80%) which were converted to the silyl ethers 13a / b (Scheme 2). Lithiation of 13a / b and reaction with FeCl₂ or TiCl₄ led to the symmetric ferrocene 14 (76%) and the titanocene 15 (34%), respectively. The mixed ferrocene 16 (63%) was prepared from 13a / b and pentamethylcyclopentadiene. Treatment of 6 / 7 with PhLi at ?78° gave a 5:3 mixture of the 1-C-phenylated alcohols 17a / b and 18a / b (71%) which were silylated to 19a / b and 20a / b , respectively. Lithiation of 19 / 20 and reaction with FeCl₂ afforded the symmetric ferrocenes 21 and 22 and the mixed ferrocene 23 (54:15:31, 79%) which were partially separated by MPLC. The configuration at C(1) of 17–22 was assigned on the basis of a conformational analysis. The reaction of the ribofuranose 24 with cyclopentadienylsodium led to the epimeric C-glycosides 27a / b and 28a (57%, ca. 1:1, Scheme 3). The in-situ reduction of 27 / 28 with LiAlH₄ followed by isopropylidenation gave 25a / b (65%) which were transformed into the ferrocene 26 (79%) using the standard method. Phenylation of 27 / 28 , desilylation, and isopropylidenation gave a 20:1 mixture of 33a / b and 34a / b (86%) which was separated by prep. HPLC. The same mixture was obtained upon phenylation of the fulvene 32 which was obtained in 36% yield from the reaction of the aldehydo-ribose 30 with cyclopentadienylsodium at ?100°. Lithiation of 33 / 34 and reaction with FeCl₂ gave the symmetric ferrocene 35 (88%). Similarly, the aldehydo-arabinose 36 was transformed via the fulvene 37 (32%) into a 18:1 mixture of 38a / b and 39a / b (78%) and, hence, into the ferrocene 40 (83%). Conformational analysis allowed to assign the configuration of 33–35 , whereas an X-ray analysis of 40 established the (1S)-configuration of 38a / b and 40 . The opposite configuration at C(1) of 38a / b and 33a / b was established by chemical degradation (Scheme 4). Hydrogenation (→ 41 and 44 , resp.), deprotection (→ 42 and 45 , resp.), NaIO₄ oxidation, and NaBH₄ reduction yielded (+)-(S)- 43 and (?)-(R)- 43 , respectively.