Ethylenediamine complexes, and

Zhu, S., Gorski, W., Powell, D.R. and Walmsley, J.A. (2006) Synthesis, structures, and electrochemistry of gold(III) ethylenediamine complexes and interactions with guanosme 5 -monophosphate. Inorganic Chemistry,... 

Tris(diamine) complexes of chromium(III) have been important from several viewpoints. First, the tris(ethylenediamine) complex is valuable as a synthetic intermediate,1 the action of heat on the chloride salt giving the cis-dichlorobis(ethylenediamine) complex and on the thiocyanate salt giving the irans-bis(iso-thiocyanato) complex. Second, the cations are resolvable, and studies2 of their optical activity have been fruitful in establishing relations between signs of Cotton effects and absolute stereochemistries. A large number of other studies, including kinetic and equilibrium measurements, have shown these complexes to be readily hydrolyzed to bis(ethylenediamine) complexes.3... 

Using a tris(ethylenediamine) complex and ammonia as the base instead of OH-, the prospect of making a trigonal cap was conceived and achieved as follows ... 

The Dias approach involves the use of three very efficient Evans oxazolidinone-mediated syn-aldol condensations. The other key steps involve a coupling reaction between the lithium acetylide-ethylenediamine complex and a tosylate followed by a methylation and a selective reduction to establish the C12-C13 (E) double bond. 

P-Arylation of electron-deficient alkenes. Aryl radicals are generated from aryl halides by reaction with the CrCh-ethylenediamine complex, and the mode of addition is similar to that of arylcopper reagents. 

Thermal deamination of tris(ethylenediamine)chromium(III) complexes is a standard preparative method for cis- and trans-diacidobis(ethylenediamine) complexes and the thermal behaviour of the starting materials has been related to their crystal structures." The cyano complex cfr-[Cr(CN)2(en)2]C104 in DMSO undergoes stepwise reduction at... 

Some 39 independent reflections are observed in the fiber diagram of ramie cellulose I-ethylenediamine complex, and there are a further 36 that are predicted within the range of these data, but which are too weak to detect. Elemental analysis indicates the presence of one ethylenedlamlne per glucose residue and density considerations require dlsaccharlde units of two chains per unit cell. 

Fig. 1.8. Structures of Pt complexes linked to intercalators. An acridine orange linked to a platinum—ethylenediamine complex and the proposed structure of a complex with Pt...

Lithium Acetylide. Lithium acetyhde—ethylenediamine complex [50475-76-8], LiCM7H -112X01120112X112, is obtained as colodess-to-light-tan, free-flowing crystals from the reaction of /V-lithoethylenediamine and acetylene in an appropriate solvent (131). The complex decomposes slowly above 40°O to lithium carbide and ethylenediamine. Lithium acetyhde—ethylenediamine is very soluble in primary amines, ethylenediamine, and dimethyl sulfoxide. It is slightly soluble in ether, THF, and secondary and tertiary amines, and is insoluble in hydrocarbons. 

Unit cells of pure cellulose fall into five different classes, I—IV and x. This organization, with recent subclasses, is used here, but Cellulose x is not discussed because there has been no recent work on it. Crystalline complexes with alkaU (50), water (51), or amines (ethylenediamine, diaminopropane, and hydrazine) (52), and crystalline cellulose derivatives also exist. Those stmctures provide models for the interactions of various agents with cellulose, as well as additional information on the cellulose backbone itself. Usually, as shown in Eigure la, there are two residues in the repeated distance. However, in one of the alkah complexes (53), the backbone takes a three-fold hehcal shape. Nitrocellulose [9004-70-0] heUces have 2.5 residues per turn, with the repeat observed after two turns (54). 

Both sodium acetylide in xylene (Air Reduction Corporation) and lithium acetylide-ethylenediamine complex (Foote Mineral Co.) are now commercially available, and have been used successfully for the ethynylation of 17-keto steroids. 

Complexes of chelating ligands like ethylenediamine (en) and diethylene-triamine (dien) can be made [119] ... 

We see from these examples that many of the carbon nucleophiles we encountered in Chapter 10 are also nucleophiles toward aldehydes and ketones (cf. Reactions 10-104-10-108 and 10-110). As we saw in Chapter 10, the initial products in many of these cases can be converted by relatively simple procedures (hydrolysis, reduction, decarboxylation, etc.) to various other products. In the reaction with terminal acetylenes, sodium acetylides are the most common reagents (when they are used, the reaction is often called the Nef reaction), but lithium, magnesium, and other metallic acetylides have also been used. A particularly convenient reagent is lithium acetylide-ethylenediamine complex, a stable, free-flowing powder that is commercially available. Alternatively, the substrate may be treated with the alkyne itself in the presence of a base, so that the acetylide is generated in situ. This procedure is called the Favorskii reaction, not to be confused with the Favorskii rearrangement (18-7). ... 

Dwyer and Sargeson have used the optical activity method in their study of the exchange between the tris-(ethylenediamine) complexes of Co(III) and Co(II)... 

The presence of ligands, either in the form of added anions such as acetate or as co-solvents or solvents, such as pyridine, markedly affect the kinetics. In pyridine or dodecylamine solvents the hydrogenation of Ag(I) acetate follows simple second-order kinetics, as does that of Cu(I) acetate. This behaviour is also shown in aqueous solutions by Ag(I) in the presence of acetate ions and by an ethylenediamine complex of Ag(I) . The rate of hydrogenation of Cu(II) acetate, on the other hand, is independent of oxidant concentration. The rate of oxidation of hydrogen by Cu(II) acetate in quinoline is also independent of oxidant concentration , but does depend on the square of the concentration of cuprous acetate which acts as a catalyst. For further details of these complicating features, reference should be made to the original papers and to Hal-pern s review ... 

Dihalides are reduced by Cr(II) to the corresponding olefin ". Allylic and benzylic halides and polyhalides are reduced more readily than simple alkyl halides, but even the latter are readily reduced by an ethylenediamine complex ofCr(ri) . ... 

Reduction of simple alkyl halides to alkanes by ethylenediamine complexes of Cr(II), denoted Cr"(en) occurs readily , e.g. for isopropyl chloride in aqueous dimethylformamide at 25 °C simple second-order behaviour is found with ki dependent on [en]/[Cr(II)] but reaching a limiting value of 1.6x 10 l.mole . sec . Competition studies between a mixture of two alkyl chlorides for Cr(II) was achieved by estimating alkane products by gas-liquid chromatography and... 

Enantioselective Br2 addition to cyclohexene (11) was accomplished by the solid-state reaction of a 2 1 inclusion complex of 10b and 11 with 7, although the optical yield was low (Sect. 2.1). However, some successful enantioselective solid-state reactions have been reported. For example, reaction of a 1 1 complex of 68 and acetophenone (64a) with borane-ethylenediamine complex (130) in the solid state gave the (i )-(+)-2-hydroxyethylbenzene (65a) of 44% ee in 96%... 

Dumond F., Marceau E., and Che M. 2007. A study of cobalt speciation in Co/Al203 catalysts prepared from solutions of cobalt-ethylenediamine complexes. J. Phys. Chem. C 111 4780-89. 

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