N-（2-甲基）苯基甘氨酸的三价和四价金属/非金属衍生物(英)

用N-（2-甲基）苯基甘氨酸合成了几种（硼、铝、铁、砷和锑）及四价（硅、钛和硒）金属/非金属衍生物。合成是在苯溶液中采用了金属/非金属的异丙氧基化合物和N-（2-甲基）苯基甘氨酸按1∶1和1∶2的配比完成的。一般情况下，合成的产物均为有色固体，以及在产物中有异丙氧基基团残留而显吸湿性。对所制成的衍生物均采用了共沸混合物分析、元素分析和光谱测定等进行了表征。     

Chemical Bonding and Electronic Localization in a GaI Amide

The electron density in a one‐coordinate [Ga^IN(SiMe₃)R] complex has been determined from ab initio calculations and multipole modeling of 90 K X‐ray data. The topologies of the Laplacian distribution and the ELI‐D match a situation having an sp³‐hybridized nitrogen with a tetrahedral arrangement of two single σ‐bonds (to carbon and silicon) and two lone pairs pointing towards gallium in a scissor‐grasping fashion. The analysis of the Laplacian distribution furthermore reveals a ligand‐induced charge concentration (LICC) in the outer core of gallium oriented directly towards the nitrogen atom, and thus in between the two lone pairs. These observations might suggest that the trigonal planar nitrogen geometry result from a dative Ga?N bond, in which the roles of the metal and the ligand have been reversed with respect to a “standard” metal–ligand interaction, that is, the metal is here electron‐donating. The ELI‐D reveals a diffuse and directional lone pair on gallium, suggesting that this complex could serve as a σ‐donor.     

Borohydride Ionic Liquids as Hypergolic Fuels: A Quest for Improved Stability

Hydrazine and its derivatives are used as fuels in rocket propellant systems; however, due to high vapor pressure, toxicity, and carcinogenicity, handling of such compounds is extremely hazardous. Hypergolic ionic liquids have shown great promise to become viable replacements for hydrazines as fuels. Borohydride‐containing ionic liquids have now been synthesized using a more efficient synthetic pathway that does not require liquid ammonia and halide precursors. Among the eight new compounds, 1‐allyl‐3‐n‐butyl‐imidazolium borohydride ( 1 ) and 1, 3‐diallylimidazolium borohydride ( 5 ) exhibit very short ignition‐delay times (ID) of 8 and 3 ms, respectively. The hydrolytic stability of borohydride compounds has been greatly improved by attaching long‐chain alkyl substituents to the imidazole ring. 1,3‐Di‐(n‐octyl)‐imidazolium borohydride ( 3 ) is a water stable borohydride‐containing ionic liquid. 1,3‐Di‐(n‐butyl)‐imidazolium borohydride ( 2 ) is a unique example of a borohydride liquid crystal. These ionic liquids have some unusual advantages, including negligible vapor pressures, good ignition delay (ID) times, and reduced synthetic and storage costs, thereby showing good application potential as environmentally friendly fuels in bipropellant formulations. In addition, they also have potential applications in the form of reducing agents and hydrogen storage materials.     

Zinc(II)‐Catalyzed Intermolecular Hydrative Aldol Reactions of 2‐En‐1‐ynamides with Aldehydes and Water to form Branched Aldol Products Regio‐ and Stereoselectively

This work describes zinc(II)‐catalyzed hydrative aldol reactions of 2‐en‐1‐ynamides with aldehydes and water to afford branched aldol products regio‐ and stereoselectively. The anti and syn selectivity can be modulated by the sizes of sulfonamides to yield E‐ and Z‐configured zinc(II) dienolates selectively. This new reaction leads to enantiopure aldol products by using a cheap chiral sulfonamide. The mechanistic analysis reveals that the sulfonamide amides of the substrates can trap a released proton to generate dual acidic sites to activate a carbonyl allylation reaction.     

A comparative study of inclusion complexes of flunarizine with alpha (α-CD) and beta-cyclodextrin (β-CD)

A detailed NMR (¹H, COSY, and ROESY) spectroscopic study of complexation of Flunarazine (FL) with α- and β-CD was carried out. ¹H NMR titration studies confirmed the formation of FL/α-CD and FL/β-CD complexes as evidenced by chemical shift variations of the proton resonances of both the CDs and FL. The stoichiometry of the complexes was determined to be 1:2 (FL/α-CD) and 1:1 (FL/β-CD) and overall binding constants were also calculated. It was confirmed with the help of ROESY spectral data that only one of the F-substituted aromatic ring and phenyl ring penetrate the α-CD cavity while both F-substituted aromatic rings as well as phenyl ring penetrates the β-CD cavity during complexation. The binding modes of FL/CD cavity interactions derived from ROESY experimental data show that the resulting complex of FL with β-CD possesses better induced fit interaction as compared to α-CD, which is responsible for the enhanced molecular stability with β-CD in comparison to α-CD. The mode of penetration of guest into the CD cavity and structures of the complexes has been established.     

Pd-catalyzed one-pot chemoselective hydrogenation protocol for the preparation of carboxamides directly from azides

Carboxamides were obtained efficiently in high yields from azides on reaction with the corresponding pre-formed activated carboxylic acids in a single-step reductive transformation using hydrogen atmosphere (balloon) under Pd/BaSO₄ or Pd/CaCO₃ catalysis. The method is highly chemoselective and compatible with extremely labile functional groups such as benzyl carbamates, benzyl ethers, benzyl esters, and olefins.     

Microwave-assisted parallel synthesis of benzofuran-2-carboxamide derivatives bearing anti-inflammatory,analgesic and antipyretic agents

A series of benzofuran-2-carboxamides of biological and medicinal significance were synthesized by a microwave-assisted one-pot parallel approach via O-alkylation/Knoevenagel condensation. All the compounds were characterized and assayed for their in vivo anti-inflammatory, analgesic and antipyretic activities. The activity data of all compounds were listed and discussed in detail, among which some derivatives exhibited potent activities of particular interest.     

Estimation of Olefin Dimerisation Products by GC/GC–MS and IR Techniques

A GC and IR based protocol was developed for monitoring the isobutene dimerisation process wherein the complete characterisation of the products was carried out by GC coupled with mass spectrometry. In the dimerisation process, LPG from FCC process comprising a mixture of saturated and unsaturated C4 hydrocarbons is subjected to a dimerisation process using a catalyst to produce C8 hydrocarbons. The reaction is carried out keeping in view the demand for high-octane blending components in gasoline. The isooctene generated in the process (mainly from the dimerisation of isobutene) is converted into isooctane having the RON and MON value 100. The monitoring process requires the use of two different column chemistries, viz., a 100 m CPSIL PONA CB non-polar column for C8 and its isomers and an Alumina PLOT column for C4 hydrocarbons. A 100 m non-polar column does not separate the C4 mixture since the column is meant for gasoline range products containing C5 and above hydrocarbons. Therefore, a need was felt for an improvised method which can handle both the analyses simultaneously. A cryogenic oven program starting from 0 °C was developed for separating the isomers of C4 hydrocarbons and C8 hydrocarbons on a single column during the single run by Detailed Hydrocarbon Analyzer. The data obtained using the cryo programme was validated with data obtained using Alumina PLOT column on C4 mixture since the Alumina PLOT column is the widely accepted column chemistry for separating the C4 hydrocarbons. An IR method for the estimation of the total olefin content was developed using 2,2,4-trimethyl pentene-1 as the reference standard. The total olefins generated during the process were identified by GC–MS, quantified by DHA-FID and validated by infrared spectroscopy. A good correlation was found between GC and IR spectral results (correlation coefficient R ² = 0.99).