乙烯亚胺与亚胺[2+2]环加成反应的理论研究

在ＨＦ／６－３１Ｇ和ＨＰ２／６－３１Ｇ站对乙烯亚胺和亚胺两模型分子的〔２＋２〕环加成反应的三种环加成方式进行了理论探讨。计算发现,环加成方式（１）和环加成方法（２）反应途径的位垒较低,反应较易进行;而环加成方式（３）位垒较高,反应较难发生。我们用前线轨道理论对其机理进行了初步探讨。     

Oxidative addition of organic halides to zerovalent palladium complexes containing rigid bidentate nitrogen ligands

Zerovalent complexes of the type Pd(Ar-BIAN)(alkene), i.e. complexes containing the rigid bidentate nitrogen ligands bis(arylimino) acenaphthene (Ar = p-Tol, p-MeOC₆H₄, o-Tol,o,o′-Me₂C₆H₃, o,o′-ⁱPr₂C₆H₃) and an electron-poor alkene have been shown to react with a variety of (organic) halides RX, including methyl, benzyl, aryl, acyl and allylic halides, to give the corresponding square planar divalent Pd(R)X(Ar-BIAN) or [Pd(η³-allyl)(Ar-BIAN)]X complexes. The new complexes obtained have been fully characterized and their fluxional behaviour in solution studied by ¹H NMR spectroscopy. The rate of oxidative addition of iodomethane to Pd(p-Tol-BIAN)(alkene) complexes was found to decrease with increasing Pd-alkene bond strength, i.e. dimethyl fumarate fumaronitrile, but oxidative addition to the fumaronitrile complex was accelerated by irradiation with a mercury lamp. Oxidative addition of allylic ha     

6 + 6 Macrocycles derived from 2,6-diformylpyridine and trans-1,2-diaminocyclohexane

While the non-templated reaction of racemic trans-1,2-diaminocyclohexane with 2,6-diformylpyridine leads to a mixture of 2?+?2 and 4?+?4 macrocyclic imines, the reaction of the isolated 2?+?2 macrocycle with cadmium(II) chloride results in the fusion of three smaller macrocyclic units into a large 6?+?6 macrocycle. The X-ray molecular structures of the hexanuclear cadmium complex of this macrocycle as well as the derived 6?+?6 protonated amine reveal multiply folded macrocycles that adopt container-type conformations.     

Imine hydrogenation catalyzed by iridium complexes comprising monodentate chiral phosphoramidites and N-donor ligands

The relatively inexpensive chiral monodentate phosphoramidite (S)-MONOPHOS may be used in combination with pyridines to prepare iridium complexes effective for catalysis of asymmetric imine hydrogenation with comparable enantioselectivity to some of those containing more costly chiral bidentate phosphines. [Ir(cod)((S)-MONOPHOS)(L)]BArF (cod = 1,5-cyclooctadiene; L = 3-methylisoquinoline, acridine, 2,6-lutidine, acetonitrile, or 2,3,3-trimethylindolenine; BArF = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) are efficient catalysts for the asymmetric hydrogenation of 2,3,3-trimethylindolenine. An important observation is that the catalyst containing acridine is more enantioselective than the catalyst derived from 2,3,3-trimethylindolenine which suggests that the other N-donor ligands are not readily displaced by the substrate during the catalytic cycle.     

Three-component coupling of aldehyde, alkyne, and amine catalyzed by silver in ionic liquid

A three-component coupling of aldehyde, alkyne, and amine was developed by using gold, copper, or silver as catalysts in ionic liquid.     

SYNTHESIS OF TRIFLUOROMETHYL-IMINES BY SOLID ACID/SUPERACID CATALYZED MICROWAVE ASSISTED APPROACH

A new solid acid/superacid catalyzed microwave assisted synthesis of trifluoromethyl-imines is described. Various α,α,α-trifluoromethylketones react readily with primary amines to produce the corresponding imines. Two different strategies have been employed; one is the application of microwave irradiation coupled with solvent-free solid acid catalysis. The other method, for highly deactivated substrates includes the use of a pressure vessel at 175 °C temperature, with solid superacid catalysis. Using the solid acid K-10 montmorillonite or the superacidic perfluorinated resinsulfonic acid Nafion-H, a wide variety of trifluoromethylated imines have been synthesized using the above methods. The products have been isolated in good to excellent yields and high selectivities. This new environmentally friendly synthetic methodology provides significantly higher yields than traditional methods during relatively short reaction times for the preparation of the target compounds.     

Electrophilic amination of enolates with oxaziridines: effects of oxaziridine structure and reaction conditions

A range of N-alkoxycarbonyl- and N-carboxamido-oxaziridines has been prepared to test the effects of oxaziridine structure on yields of enolate amination product. Side-products arising from reaction of aldehyde-derived oxaziridines with base were identified, while a ketone-derived oxaziridine afforded moderate yields of amination product with stabilised carbanions.     

Co-immobilized formate anion and palladium on a polymer surface: a novel heterogeneous combination for transfer hydrogenation

A novel heterogeneous combination of a formate reagent and palladium catalyst co-immobilized on a resin support has been developed and shown to be highly efficient and recyclable for transfer hydrogenation of alkenes, imines, nitroarenes and 1,2-dicarbonyl compounds.     

A novel one-pot reductive amination of aldehydes and ketones with lithium perchlorate and zirconium borohydride-piperazine complexes

A novel, one-pot reductive mono-alkylation method of amines (primary and secondary), 1,2-phenylenediamine, O-trimethylsilylhydroxylamine, and N,N-dimethylhydrazine was developed using LiClO₄ (5 mol %) as a source for in situ generation of imine, iminium ion, oxime, and hydrazone, and zirconium borohydride-piperazine complex as reducing agent. This condition is especially useful for situations in which it is not practical to use the amine in excess (as is typically the case under acid-catalyzed conditions) or for acid-sensitive compounds.