The Coordination Chemistry of the Ylide Adduct O2CC(PPh3)2; Preparation,Crystal Structures,and Spectroscopic Properties of [Cl3In{O2CC(PPh3)2}], [Cl2Sn{O2CC(PPh3)2}], and [I2In{O2CC(PPh3)2}2]I

The betain like carbodiphosphorane CO₂ adduct O₂CC(PPh₃)₂ ( 1a ) can serve as a ligand versus hard Lewis acids from main group compounds. Thus, reaction of 1a with InCl₃, InI₃ and SnCl₂ in polar solvents leads to the addition compounds [Cl₃In{O₂CC(PPh₃)₂}] ( 2 ), [Cl₂SnO₂CC(PPh₃)₂}] ( 3 ) and the salt like compound [I₂In{O₂CC(PPh₃)₂}₂]I ( 4 ) in good yields. Whereas in the indium compounds 1a acts as a chelating ligand, in the tin compound the molecule coordinates with one oxygen atom only as a monodentate ligand. 4 has a pyramidal structure with a stereochemical active pair of electrons. All compounds could be characterized by X‐ray analyses and the usual spectroscopic methods.     

Stereoselective synthesis of tri- and tetrasubstituted oxepanes via n-Bu3SnH mediated 7-endo-trig vinyl radical cyclisation

A stereoselective 7-endo-trig cyclisation of homopropargyl and phenyl homopropargyl derivatives of Baylis-Hillman adducts using n-Bu₃SnH/AIBN mediated vinyl radical cyclisation affords tri- and tetrasubstituted oxepanes, respectively, in good yields.     

C_（60）与含烯丙基胺聚合物加成物的荧光行为

Ｃ_（６０）与含烯丙基胺聚合物加成物的荧光行为田慧洁，陈立桅，姚光庆，金朝霞，李福绵（北京大学化学系北京１００８７１）关键词脂肪胺，Ｃ_（６０），聚烯丙基胺，荧光Ｃ６０是一高度对称的笼状碳簇分子，室温下难以观察到荧光现象［１］，但我们发现它与聚烯丙基胺...     

Qualitative study of in vivo melphalan adduct formation in the rat by miniaturized column-switching liquid chromatography coupled with electrospray mass spectrometry

In a general study of DNA adduct formation with melphalan, rats were intravenously injected with a single high dose (10 mg kg(-1)). Adduct formation was studied at the nucleoside level in the target organs liver, bone marrow, kidney and blood with the use of 2D liquid chromatography/tandem mass spectrometry (LC/MS/MS). Adducts of dGuo and dAdo were detected under selected reaction monitoring in liver and bone marrow 10 h after administration of melphalan. In the DNA hydrolysates from kidney and blood a Gua-melphalan adduct was found, although in very low abundance. These first results of the search for in vivo-formed melphalan adducts in the rat showed that our miniaturized LC/MS technique is useful for investigating this type of compound. More experiments will be performed in this area to gather more information about the pharmacokinetics and the quantity of adducts formed.     

Siloxyallenes revisited. A useful functional intermediate for the synthesis of (Z)-β-branched Morita-Baylis-Hillman type adducts and (Z)-chalcones

Siloxyallenes proved to be a useful functional intermediate in the preparation of (Z)-β-branched Morita-Baylis-Hillman type adducts by the reaction of aldehydes with silylacetylenes or siloxypropynes. Various (Z)-chalcones were stereoselectively synthesized from siloxypropynes via siloxyallenes.     

Synthesis of β-branched Morita-Baylis-Hillman-type adducts from 1,3-diaryl-2-propynyl trimethylsilyl ethers and aldehydes catalyzed by potassium tert-butoxide

1,3-Diaryl-2-propynyl trimethylsilyl ethers were easy to isomerize into the corresponding siloxyallenes using a catalytic amount of potassium tert-butoxide under very mild conditions. The siloxyallenes reacted in situ with various aldehydes to afford Z-selective β-branched Morita-Baylis-Hillman-type adducts in a one-pot reaction after acid treatment.     

A facile and efficient stereoselective synthesis of highly functionalised trisubstituted alkene derivatives of ferrocenealdehyde

The reaction of the Baylis–Hillman adduct 2 of ferrocenealdehyde with various oxygen and carbon nucleophiles in the presence of montmorillonite K10 clay catalyst furnished highly functionalised trisubstituted alkene derivatives of ferrocenealdehyde in excellent yield. Synthetic use of one of products 7 has been demonstrated with the synthesis of a 1,3-diyne ether derivative of ferrocene 16 via an Eglinton coupling reaction.     

Effects of liquid chromatography mobile phase buffer contents on the ionization and fragmentation of analytes in liquid chromatographic/ionspray tandem mass spectrometric determination

The effects of liquid chromatography mobile phase buffer contents on the ionization and fragmentation of drug molecules in liquid chromatographic/ionspray tandem mass spectrometric (LC/MS/MS) determination were evaluated for simvastatin (SV) and its hydroxy acid (SVA). The objective was to improve further the sensitivity for SV by overcoming the unfavorable condition caused by the formation of multiple major adduct ions and multiple major fragment ions when using ammonium as LC mobile phase buffer. Mobile phases (70:30 acetonitrile-buffer, 2 mM, pH 4.5) with buffers made from ammonium, hydrazine or alkyl (methyl, ethyl, dimethyl or trimethyl)-substituted ammonium acetate were evaluated. Q1 scan and product ion scan spectra were obtained for SV in each of the mobile phases under optimized conditions. The results showed that, with the alkylammonium buffers, the alkylammonium-adducted SV was observed as the only major molecular ion, while the formation of other adduct ions ([M + H](+), [M + Na](+) and [M + K](+)) was successfully suppressed. On the other hand, product ion spectra with a single major fragment ion were not observed for any of the alkylammonium-adducted SVs. The affinity of the alkylammoniums to SV and the basicity of the alkylamines are believed to be factors influencing the formation and abundance of molecular and fragment ions, respectively. Methylammonium acetate provided the most favorable condition among all the buffers evaluated and improved the sensitivity several-fold for SV in LC/MS/MS quantitation compared with that obtained using ammonium acetate buffer. Better precision for SV in both Q1 and SRM scans was observed when using methylammonium buffer compared with those using ammonium buffer. The mobile phase buffer contents did not seem to affect the ionization, fragmentation and chromatography of SVA. The results of this evaluation can be applied to similar situations with other organic molecules in ionspray LC/MS/MS determination.     

氨基硝基苯并二氧化呋咱与二甲基甲酰胺分子加合物的制备和晶体结构

氨基硝基苯并二氧化呋咱 (ANBDF)可与二甲基甲酰胺 (DMF)形成稳定的分子加合物 (两者摩尔比为 1∶1) ,未见文献报道 .报道了该加合物的合成、晶体结构、晶体学数据和结构参数 .该加合物为淡黄色透明晶体 ,其中ANBDF与DMF分子以氢键结合 ,属单斜晶系 ,空间群P2 1 /n .     

Interaction of dihydroxy host systems with glycols. A comparative study of the crystal structures of 1:1 molecular complexes of 1,4-butanediol with 2,5-bis(4-chlorophenyl)hydroquinone andtrans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene

The title compounds crystallize in space groupC2/c withZ=4; C₁₈H₁₂O₂Cl₂·HO(CH₂)₄OH,a=16.186(3),b=7.626(1),c=16.939(3) Å, =91.32(2)°,R _F =0.048 for 1743 observed MoK reflections; C₂₆H₂₀O₂·HO(CH₂)₄OH,a=11.881(3),b=13.009(4),c=16.689(4) Å, =110.67(2)°,R _F =0.066 for 1783 data points. Both structures feature centrosymmetric hydrogen-bonded (OH)₄ rings formed by molecular components located in special positions. Different packing modes account for the observed conformations (g ⁺ ag ^– andaaa, respectively) of 1,4-butanediol and its possible replacement by 1,2-ethanediol as a guest in the former crystal structure. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82009 (25 pages).Dedicated to Professor H. M. Powell.