Cation-pi binding of an alkali metal ion by pendant alpha,alpha-dimethylbenzyl groups within a dinuclear iron(III) structural unit

We report here on the cation-pi binding of potassium ions by benzyl groups in a coordination complex. The results demonstrate the cation-binding power of the benzyl group and consequently the potential for aromatic groups to interact with alkali metal ions even in aqueous media.     

Labelling studies of the ring opening of 1-bromo-2-chloro-3,3-dimethylcyclopropene

1-Bromo-2-chloro-3,3-dimethylcyclopropene reacts with methyl lithium in the presence of 2,3-dimethylbut-2-ene at above ?70°C to give (4); ¹²C labelling shows that C-2 of the cyclopropane becomes the centre carbon of the allene.     

Syntheses of 1-(2-bromo-3-hydroxypropyl)-and 1-(2-bromo-2-propenyl)isatins and theirβ-thiosemicarbazones

Only the bromine atom at the primary carbon atom participates in nucleophilic replacement by a trifluoroacetate ion and elimination of HBr in 1-(2,3-dibromopropyl)isatin.Institute for the Biological Protection of Vegetation, Academy of Sciences of the Republic of Moldova, 2060 Kishinev, Moldova. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 308–310, March, 1998.     

N-(S)-(1'-氯甲基-2'-烷基)-2-乙基-2-(4S-烷基-4,5-二氢恶唑)丁酰胺的合成

由L-氨基酸不对称合成了4种新型手性化合物(6a，6b，7a，7b)，其结构经IR，^1HNMR，^1^3C NMR及MS等证实。     

Enantioselective synthesis of (S)-N,N-diethyl-2-formyl-2-(methoxymethoxy)butyramide,a key intermediate for 20(S)-camptothecin analogues,via asymmetric bromolactonization

A new enantioselective synthetic method for enantiomerically pure (S)-N,N-diethyl-2-formyl-2-(methoxymethoxy)butyramide 5, a versatile key intermediate has been developed employing asymmetric bromolactonization using (S)-proline as the chiral auxiliary.     

Di(2-ethyl hexyl) butyramide and di(2-ethyl hexyl)isobutyramide as extractants for uranium(VI) and plutonium(IV)

The extraction of uranium(VI) and plutonium(IV) from nitric acid into n-dodecane was studied using two isomeric branched alkyl amides, di(2-ethyl hexyl) butyramide (DEHBA) and di(2-ethyl hexyl) isobutyramide (DEHIBA). The extraction ratios of Pu(IV) at relatively high acidities were higher than the corresponding values for U(VI) in the case of DEHBA. However, with DEHIBA the values for Pu(IV) were negligibly small. Pu(IV) was found to be extracted as trisolvate by DEHBA and as disolvate by DEHIBA. U(VI) was extracted by both the amides. From the study of the extraction reactions at different temperatures, it was shown that all the reactions in the present investigation were enthalpy favoured and entropy disfavoured. Separation of Pu(IV) from bulk of U(VI) was feasible. However, the purity of the separated plutonium was not satisfactory in batch extraction studies.     

Synthesis and Crystal Structure of Copper (Ⅱ) Compound with 3,3''''-Azobispyridine Ligand [Cu(NO_3)_2(H_2O)_2(3,3''''azpy)_2]

1INTRODUCTIONThedevelopmentofinorganicsupramoleculararchitecturesisarapidlydevelopedareaofresearchthathasimplicationsfortherationaldesignoffunctionalmaterials[1,2].Aconvenientpathtoobtainapolymericstructureistouseabidentateligand,suchaspyrazine,4,4-bipyridineor4,4?azobispyridinetolinkthemetalions,forminganinfinitestructure[3,4].Theuniquedirectionality,strength,andcomplementarityofnon-covalenthydrogenbondingplayanimportantroleintheconstructionofavarietyofmotifsformolecularself-assemblyandre…     

Molecular association in 2-bromo-2-chloro-1,1,1-trifluoroethane (Halothane)

Intermolecular interactions and the role of fluorine substitution have been investigated for a halogenated-ethane anesthetic. 2-Bromo-2-chloro-1,1,1-trifluoroethane, BrClCHCF₃ (Halothane), has been in situ pressure frozen in a diamond anvil cell and its structure determined by single-crystal X-ray diffraction at 1.85(5) GPa/296 K. Crystal is triclinic, space group . In this racemic structure the enantiomorphic molecules are substitutionally disordered at the same general positions in that way that bromine and chlorine atoms occupy the same site at the 50:50 ratio. Despite the fact that only the Br and Cl atoms are disordered, the crystal packing is dominated by halogen?halogen and halogen?hydrogen interactions. This X-ray diffraction study provides structural explanation of considerably increased vapor pressure of Halothane compared to its hydrogenated analogue.     

Diene autocondensation of 3,3-dimethyl-2-phenyl- and 3,3-dimethyl-2-(2-thienyl)-3H-pyrroles

Chemistry of Heterocyclic Compounds -