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排序方式: 共有123条查询结果,搜索用时 31 毫秒
1.
M. Jonathan Fray Paul Allen Paul R. Bradley Clare E. Challenger Michael Closier Tim J. Evans Mark L. Lewis John P. Mathias Carly L. Nichols Yvonne M. Po-Ba Hayley Snow Mark H. Stefaniak Hannah V. Vuong 《Tetrahedron》2006,62(29):6869-6875
The synthesis of ten substituted aminomethylene tetrahydro-isoquinolines is described, proceeding in eight steps from 5-hydroxyisoquinoline via reductive amination of N-Boc tetrahydro-isoquinoline 5-carboxaldehyde. Likewise, reductive amination was used to prepare four substituted dihydro-isoindoles from the corresponding aldehyde. The dihydro-isoindole ring system was conveniently accessed via a 2+2+2 cycloaddition reaction. 相似文献
2.
A series of new poly(amide imide)s was prepared from new diacid containing sulfone, ether, amide and imide groups with various aromatic diamines. The diacid was synthesized via four steps, starting from reaction of 4-aminophenol with 4-nitrobenzoyl chloride in the presence of propylene oxide afforded N-(4-hydroxy phenyl)-4-nitrobenzamide. In the second step, reduction of nitro group resulted in preparation of 4-amino-N-(4-hydroxy phenyl) benzamide. In the next step for the preparation of diamine, the reaction of 4-amino-N-(4-hydroxy phenyl) benzamide with bis-(4-chlorophenyl) sulfone in the presence of K2CO3 was achieved. The prepared sulfone ether amide diamine was reacted with two moles of trimellitic anhydride to synthesize related sulfone ether amide imide diacid. The precursors and final monomer were characterized by FT-IR, H-NMR and elemental analysis. Direct polycondensation reaction of the sulfone ether amide imide diacid with different diamines in the presence of triphenyl phosphite afforded five different poly (sulfone ether amide imide amide)s. The obtained polymers were fully characterized and their physical properties including thermal behavior, thermal stability, solubility, and inherent viscosity were studied. 相似文献
3.
The alicyclic ring contraction of perfluoro-1-phenyltetralin in reaction with antimony pentafluoride
Perfluoro-1-phenyltetralin (1) heated with antimony pentafluoride at 130 °C, then treated with water, gave a mixture of perfluorinated 3-methyl-2-phenylindenone (3), 3-methyl-2-phenylindene (4), 3-hydroxy-1-methyl-3-phenylindan (5), 1-methyl-3-phenylindan (6), 9-methyl-1,2,3,4,5,6,7,8-octahydroanthracene (7), and 1,9-dimethyl-5,6,7,8-tetrahydro-β-naphthindan (8). When heated with SbF5 in the presence of HF, then treated with water, compound 1 is transformed to a mixture of products 3-6. The reaction at 170 and 200 °C forms compounds 3-6 together with perfluoro-2-(cyclohexen-1-yl)-3-methylindene (10). 相似文献
4.
Two novel assembling systems 3 and 4, with the structures of C6F5CF2−?H+N(Me)2CH2CH2(Me2)N+H?−CF2C6F5 and C6F5CF2I?N(Me)2CH2CH2(Me)2N?ICF2C6F5, respectively, have been generated from the solution of heptafluorobenzyl iodide 1 and N,N,N′,N′-tetramethylethylenediamine 2 in dichloromethane. Their structures have been characterized by X-ray diffraction analysis, NMR and IR spectroscopy. Intermolecular N?I halogen bond and F?H hydrogen bond are revealed to be the driving forces for their formation. 相似文献
5.
An easy to handle and stable racemization catalyst for secondary alcohols is obtained by an in situ mixture of readily available [Ru(cymene)Cl2]2 with chelating aliphatic diamines. Optimization of the reaction revealed that N,N,N′,N′-tetramethyl-1,3-propanediamine as ligand racemizes aromatic alcohols completely within 5 h. This easy to handle and stable catalytic system is combined with a lipase-catalyzed resolution to provide an efficient dynamic kinetic resolution of secondary alcohols. 相似文献
6.
Shahram Mehdipour-Ataei 《European Polymer Journal》2005,41(1):65-71
Terephthalic acid bis(carboxydiphenyl methyl)ester (TBE) as a new monomer for the preparation of polyamides was synthesized through the nucleophilic substitution reaction of benzilic acid with terephthaloyl chloride. This diester-diacid (TBE) was characterized using conventional spectroscopic methods. Polycondensation reactions of TBE with different aromatic and semi-aromatic diamines via Yamazaki method resulted different poly(ester amide)s. All the polymers were characterized and their physical and thermal properties were studied. 相似文献
7.
Jianhua Hu Yinjun Xie Hanmin Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(28):7400-7404
A new and atom‐economic palladium‐catalyzed aminomethylamination of allenes with aminals by C N bond activation is described. This direct and operationally simple method provides a fundamentally novel approach for the synthesis of 1,3‐diamines. Mechanistic studies suggest that a unique cationic π‐allylpalladium complex containing an aminomethyl moiety is generated as a key intermediate through the carbopalladation of the allene with a cyclometalated palladium–alkyl species. 相似文献
8.
The polysiloxane-based alicyclic episulfide resin (PSCER) was synthesized through substitution of oxygen atoms in 1,3-bis[2-(3{7-oxabicyclo[4,1,0]hepyl})ethyl]-tetramethyldisiloxane with sulfur atoms using potassium thiocyanate (KSCN) as the reagent. The product was purified by column chromatography, and the by-products were isolated. It was found by 1H-NMR and 13C-NMR that the by-products were cycloolefins formed by desulfurization of the episulfide groups. PSCER was unstable; desulfurization took place easily, especially at high temperatures. The PSCER resin could not be cured with methylhexahydrophthalic anhydride (MeHPPA). When m-phenylenediamine or isophorondiamine was used as curing agent, PSCER showed a higher reactivity compared with the parent epoxide. However, the reactivity of the alicyclic episulfide was much lower than the polysiloxane based aliphatic episulfide for the steric hindrance of the six member ring. Desulfurization took place upon curing of the alicyclic episulfide resin, therefore the cured resin showed poor mechanical properties. Thermal stability of cured PSCER resin was also poor on account of low bonding energy of C-S and crosslinking density. 相似文献
9.
Heterocycles derived from Tröger's base were shown to complex with metal salts in 2:1 ligand:salt ratios as monodentate or bidentate ligands depending on structure. 相似文献
10.
《合成通讯》2013,43(4):679-686
Abstract 2-(Cyclohex-2′-enyl)-5,5-dimethyl-3-hydroxycyclohex-2-enone undergoes regioselective heterocyclization to give bridged heterocycles 5a,b and 7 on treatment with pyridine hydrotribromide or hexamethylenetetramine hydrotribromide (1 h); or elemental bromine (7 h); N-iodosuccinimide in acetonitrile at 0–5°C (1 h) and conc. H2SO4 at 0–5°C (2 h), respectively. 相似文献