SUBSTITUTION REACTIONS OF ALKANES——BROMINATION OF PENTANE,HEXANE AND HEPTANE

In the photo-bromination of pentane, hexane and heptane with bromine, N-bromo-diethylamine or N-bromo-succinimide, the authors found that the mono-bromo-pentanes, -hexanes and-heptanes obtained contain the isomers in the same proportions disregarding whatever brom-inating reagent is used. Among the isomers, 2-bromo-compounds occur in dominant quantitieswhile 1-bromo-compounds are nearly nil. The authors attributed these phenomena mainly tothe low mobility of bromine molecules but the rearrangement of the alkyl free radicals fromprimary to the secondary. Compared with chlorination, chlorine molecules are more mobileand combine with alkyl free radicals rather rapidly before rearrangement occurs, which makes1-chloro-isomer more abundant.     

INSERTION REACTIONS OF CARBOETHOXYCARBENE TO ALKANES

The insertion reactions of carboethoxycarbene on n-pentane, n-hexane, n-heptane and n-octane are studied. The products of each of the reactions were separated and identified by gaschromatography-mass spectrometry. The ratio between the products inserted on various C-atoms in each reaction is not coincident with that calculated from the reaction probability.This can be explained by a suggested reaction mechanism, in which the carbonium ion or freeradical, first formed during the abstraction of H-atom by the carbene, will rearrange partial-ly before recombination with the carboethoxy-methyl anion or free radical.     

SOME INTERESTING REACTIONS OF AN N－BROMOMETHYL QUATERNARY AMMONIUM SALT WITH HALOPHILIC REAGENTS

ＳＯＭＥＩＮＴＥＲＥＳＴＩＮＧＲＥＡＣＴＩＯＮＳＯＦＡＮＮ－ＢＲＯＭＯＭＥＴＨＹＬＱＵＡＴＥＲＮＡＲＹＡＭＭＯＮＩＵＭＳＡＬＴＷＩＴＨＨＡＬＯＰＨＩＬＩＣＲＥＡＧＥＮＴＳ￥ＧｕｏＦｅｎｇＨＵＡＮＧａｎｄＸｉａｏＴｉａｎＬＩＡＮＧ（Ｉｎｓｔｉｔｕｔｅｏ...     

REACTIONS OF 1-ACETOXY ALLYLIC PHOSPHONATES UNDER PALLADIUM(0) CATALYSIS

l-Acetoxy allylic phosphonates rearrange regioselectively to γ-acetoxy α,β-unsaturated phosphonates under the catalysis of Pd(0). l-Acetoxy allylic phosphonates act as the precursors of phosphonatedπ-allylic cations in palladium(0) catalyzed reactions[1]. The reactions of l-acetoxy allylic phosphonates under palladium(0) catalysis with nucleophiles have been reported. 1-4 These reactions are highly regio- and stereoselective. We wish to report here the palladium(0) catalyzed reaction of l-acetoxy allylic phosphonates in the absence of a nucleophile.     

SOME PROPERTIES OF CLOSED-NET-DIAGRAMS OF n k(k≥3) PHASE MULTISYSTEMS

In this paper, some properties of closed-net-diagrams (CND's) of n 3 and n 4 phasemultisystems are discussed, and the theorem on the so-called Divariant Assemblage Charac-teristic Stability Polygons is proposed. The theorem states: Any divariant assemblage ofn k(k≥3) phase multisystems can be stable in a k-polygon possessing no diagonals inappropriate closed-net-diagrams at most, and in a triangle at least. Following the proof ofthis theorem, the authors specially emphasize that this theorem does not mean that there mustexist k-polygons possessing no diagonals in each closed-net-diagram or realistic phase diagramof n k phase multisystems, even though the realistic phase diagram has the maximum closure.     

ELECTRON-TRANSFER REACTIONS OF CROSSLINKED POLY(1-PYRIDINIOMETHYL)STYRENE CHLORIDE 2. REDUCTION OF NITRO-COMPOUNDS

Continuing the study of electron transfer reactions of polypyridiniomethylstyrene chloride (PSPyCl), the reduction of nitro-compounds by the PSPyCl-Zn system was investigated. In general azoxy compounds were obtained as chief intermediate product of reduction. Reduction of nitrobenzo-15-crown-5 and its homologues give a new class of bis-crown ether compounds——azoxy-bisbenzocrown ethers. Azoxybisbenzocrown ethers undergo photoinduced trans-cis isomerization, which is reversible on irradiation with UV and on storage in darkness, similar to the case of azobiscrown ethers. Investigation of solvent extraction of various cations by azobiscrown ether isomers shows that cis-azoxybisbenzo-15-crown-5 exhibit good selectivity toward Nd~(3 ) from other rare earth cations.     

PRELIMINARY COMMUNICATIONS: SUBSTITUTION OF tris(2,2′-BIPYRIDINE)COBALT(III) BY CARBONATE ION

Abstract

This communication reports the instability of tris(2,2′-bipyridine)cobalt(III) toward ligand substitution. 2,2′-Bipyridine(“bpy”) has been recognized as one of the most potent ligands and used to prepare many kinds of metal complexes. Nevertheless, one of the authors¹ reported the preparation of [Co(CN)₂(bpy)₂]Cl, which was obtained by the reaction of [Co(bpy)₃]³⁺ with cyanide ion in water. The reaction was reported to occur within five minutes at room temperature. The strong nucleophilicity of the cyanide ion might be responsible for this kind of substitution.     

STUDIES ON THE REACTIONS OF PHOSPHORO-(OR PHOSPHONO-)BIS-(ISOTHIOCYANATIDO)- THIOATES WITH AMINES

Four series of new phosphorus compounds with general formulas Ⅰ, Ⅱ, Ⅲ and Ⅳ have been prepared by the reactions of phosphoro-(or phosphono-)bis-(isothiocyanatido)-thioates separately with amines. The structures of these compounds have been confirmed by IR and ~1HNMR. In addition, some of them have been further identified by MS and X-ray.     

PHOTOINDUCED S_(RN)1 REACTIONS OF ARYL HALIDES WITH CARBAZOLYL NITROGEN ANION

The photoinduced reactions of aryl halides with carbazolyl nitrogen anion,in dimethyl sulfoxide,yield the corresponding N-arylated products.These reactions are suggested in terms of the S_RNl mechaism of nucleophilic substitution.     

SYNTHESIS OF SOME NORTROPANE DERIVATIVES

Some novel nortropane derivatives represented by structure Ⅱ and Ⅲ weresynthesized and tested for their affinity for dopamine receptors.     

THE NATURE OF INTERMEDIATES OF ISOMERISATION AND OF NUCLEOPHILIC SUBSTITUTION OF β-CHLOROALKYLTHIOCARBOXYLIC ACID DERIVATIVES

Abstract

The addition of sulfenchlorides to the derivatives of unsaturated carboxylic acids results in the formation of kinetically controllable adducts, which in solution and even in a solid state isomerize into thermodinamically stable ones. The derivatives of β-chloroalkyl tiocarboxylic acids readily enter nucleophilic substitution reactions, particularly the reaction of hydrolytic splitting of C-C1 bonding. There still remains a problem to be solved concerning the nature of the intermediates which appear in the process of isomerisation and hydrolysis of these compounds. To solve the problem the research was carried out on the effect of chlorine and perchlorate ions concerning the rate of hydrolysis and isomerisation of the derivatives 2(3)-chloro-3(2)-alkylthio-2-methylpropanoic acids.     

SPECTROSCOPIC and REDOX BEHAVIOUR OF SOME COPPER(II) ‐ THIOETHER COMPLEXES

Abstract

The features of electronic spectra and redox chemistry of a number of Cu(II)-thioether complexes have been examined. The origin of the intense absorption in the region around 14,000–16,000 cm^?1 is attributed to (π)S → d(Cu²⁺) CTB, that obscures the less intense d-d (Cu²⁺) band. The relationship between spectral characteristics and redox potentials of CuL^2+/+ couples values is discussed.     

THE SYNTHESIS,PHYSICAL, AND SPECTRAL PROPERTIES,AND SOME REACTIONS OF A NEW STABLE bis-α-LACTAM (AZIRIDINONE) WITH A TERPENE SKELETON

A synthesis of a new stable bis-α-lactam, cis-1,1′(p-menth-1,8-ylene) bis(3-tert-butyl-2-azirididone) (4), derived from p-menthane, is described. Complete spontaneous thermal decomposition required 1h of reflux in boiling n-decane (b.p. 174°C) and the products are 2,2-dimethylpropanal (pivalaldehyde) (6) and 1,8-diisocyano-p-menthane (7). Reaction with benzylamine yielded the unexpected bis-benzylamide (13a), while reaction with sodium methoxide gave the bis-α-amino acid ester (14).     

SYNTHESIS, SPECTRAL AND MAGNETIC CHARACTERISATION OF SOME BIMETALLIC ALKOXIDES OF NICKEL(Ⅱ)WITH GALLIUM(Ⅲ)AND ZIRCONIUM(IV)

Some interesting bimetallic isopropoxides of nickel(Ⅱ) with gallium(Ⅲ) and zirconium(Ⅳ), Ni[Ga(OPr~1)_4]_2 and Ni[Zr_2(OPr_1)_9]_2 have been synthesized by the interaction of NiCl_2·2Pr~1OH with K[Ga(OPr~1)_4],and K[Zr_2(OPr~1)_9] respectively, in 1:2 molar ratio. These bimetallic isopropoxides undergo facile alcohol interchange reactions with primary alcohols. However, reactions with tertiary alcohols result in the isolation of partially substituted derivatives with the compositions, Ni[Ga(OPr~1)(OBu~t)_3]_2 and Ni[Zr_2(OPr~1)_3(OBu~t)_6]_2. Characterisation of these derivatives has been made on the basis of elemental analyses, infrared, electronic spectral and magnetic susceptibility measurements. These studies suggest an octahedral geometry for nickel(Ⅱ) in the primary bimetallic alkoxides, while in the case of secondary and tertiary derivatives, an equilibrium is suggested between octahedral and tetrahedral forms.##属性不符     

STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES [ⅤⅢ]——THE STEREOCHEMISTRY OF SOME REACTIONS OF THE MIXED ANHYDRIDE OF O-ETHYL PHENYLPHOSPHONOTHIOIC AND O-ETHYL O-PHENYL PHOSPHOROTHIOIC ACIDS

In this paper, (1) alkaline methanolysis, (2) acid methanolysis, (3) alkaline hydro-lysis, (4) aminolysis of (+)-(R)-(R)-mixed anhydride 1 of O-ethyl phenylphosphonothioic:and O-ethyl O-phenylphosphorothioic acid, (5) its reactions with KSH and (6) with PCl_5have been studied. The cleavage of P-O-P bonds in all the reactions studied has beenfound. In reactions (1)-(4), attacks of nucleophiles occur to the phosphorus atoms of phos-phonyl groups forming the products with inversion of configuration, while the configurationof the phosphorus atoms of phosphoryl groups which are not attacked is retained. Inreaction (5), the uncleophile -SH attacks the phosphorus atom of the phosphonyl group,but a racemic product results because of the formation of ph(EtO)P(S)~- which loseschirality; the configuration of the phosphorus atom of the phosphoryl group which is notattacked is still retained. In reaction (6), both the phosphonyl and phosphoryl groups arechlorinated giving as products (-)-(R)-thiophophonyl chloride 1     

REACTIONS OF ORGANODILITHIUM COMPOUND WITH ALKYL HALIDES

The mechanism of the electron transfer reaction of 1,4-dilithio-tetraphenyl-1,3-butadiene with methyl iodide was studied.     

ON THE SYMMETRY ANALYSIS OF CHELETROPIC REACTIONS

By means of local symmetry analysis, the energy correlation diagrams of cheletropic reactions are built up by use of conventional quantum chemistry method to give the Woodward-Hoffmann rules.     

A STUDY OF THE REACTIONS OF BENZYL ETHERS WITH DIBROMOCARBENE

Using potassium carbonate as base and a polyethylene glycol with an average molecular weight of 600 (PGE600) as phase transfer catalyst, reaction of benzyl ethers with dibromocarbene leads to benzylic C—H bond insertion products, aromatic aldehydes are also formed as one of the products.     

THE SYNTHESES OF POLYQUINOLINES WITH 2,2''''-PYRIDYLQUINOLINE AND 2,6-DIQUINOLYLPYRIDINE AS LIGAND AND THEIR APPLICATIONS IN SOME CATALYTIC REACTIONS

The polyquinolines with 2,2'-pyridylquinoline as bidentate and 2,6-diquinolylpyridine as tridentate ligand have been prepared from 4,4-dlamino- 3,3'-dibenzoyldiphenyl ether, 4,4'-diacetyldiphenyl ether and 1,4-bis (2-acetylpyridyl-6-oxy) benzene, 2,6-diacetylpyridine, respectively. These polyquinoline-supported ligands have been used in hydrogenation and hydroformylation of olefins with some transition metal complexes.     

MULTIDENTATE LIGAND EXCHANGE KINETICS:REACTIONS OF AMINOCARBOXYLATO-FERRATE(Ⅲ) COMPLEXES WITH 4-(2-PYRIDYLAZO) RESORCINOL

The kinetics and mechanism of ligand substitution reactions of nitnlotriacetatoiron(Ⅲ),(Fe(NTA)],and N-(2-hydroxycthyl)-ethylencdiaminetriacetatoiron(Ⅲ),[Fe(HEDTA)],complexes with 4-(2-pyridylazo) resorcinol (Par) has been investigated at pH=9.0±0.02,I=0.1mol·l^-1 (NaClO₄,and temp.=25±0.1℃ and 30±0.1℃ respectively. The reaction has been studied spectrophotometrically at 496 nm. (λmax of Fe(Par)₂. In both reactions the final product was [Fe(Par)₂]^-. The values of second order rate constants for NTA and HEDTA exchange reactions are (10.0±0.8)×10¹¹·mol^-1·s^-1 and (2.7±0.1)×10^-1·mol^-1·s_-1 respectively. The reactions of NTA and HEDTA exchange were studied in the pH range 6-9.5 and 7-10.85 respectively. The rate of reacton of [Fe(NTA)] with HPar^- first increases with pH and then levels off. However,in the case of [Fe(HEDTA)] reaction,the rate increases monotonically with increase of pH in the specified range.