Ethylenediamine dissolving metals

Sterically hindered epoxides are sometimes easier to reduce by dissolving metals 2-methyl-2,3-epoxybutane gave, after treatment with lithium in ethylenediamine at 50° for 1 hour, 74% of 3-methyl-2-butanol and 8% of 2-methyl-2-butanol [659. ... 

Experimental evidence in support of this explanation is the fact that lithium added to a solution of lithium iodide in ethylenediamine dissolves without imparting a blue color to the solution—i.e., reacts immediately to give the amide. By contrast, lithium added to a solution of lithium chloride in ethylenediamine dissolves and imparts a deep blue color to the solution. The catalytic effect of iodide anion may be related to the effect of iodide anion on the electron spin resonance (ESR) absorption of solutions of alkali metals in liquid ammonia. Catterall and Symons (2) observed a drastic change in the presence of alkali iodides but very little change in the presence of alkali bromides or chlorides. They attributed this change to interaction of the solvated electron with the 6 p level of the iodide anion. 

Carbon-carbon double bonds are often stable to dissolved metals. Considerable amounts of norbornane (54) are obtained when either norbomadiene (53) or nor-bornene (56) is reduced by calcium in methylamine-ethylenediamine (Scheme 4.15) [35]. The C-C double bonds in both substrates are highly strained, which enables the reduction to proceed smoothly. In the reduction of diene 53, a tricyclic compound 55 is produced as a by-product in 18% yield. 

Diborane in tetrahydrofuran reduces epoxides, but the yields are low, and other products are formed by pathways that result from the electrophilic character of diborane/ Diborane reduction occurs in better yield in the presence of BH4, but the electrophilic role played by diborane is still evident because the dominant product is that resulting from addition of hydride at the more substituted carbon." Dissolving metals, particularly lithium in ethylenediamine, give synthetically useful yields of alcohols from epoxides/ ... 

Epoxides can also be reduced to saturated alcohols. Lithium aluminum hydride acts as a nucleophilic reducing agent, and the hydride is added at the less substituted carbon atom of the epoxide ring. Lithium triethylborohydride is more reactive than LiAlH4 and is superior for epoxides that are resistant to reduction. Reduction by dissolving metals, such as lithium in ethylenediamine, also gives good yields. 

This cluster is prepared from the reaction of an alloy of Pb with an alkali metal, dissolved in liquid ammonia with the crown ether, crypt, dissolved in ethylenediamine. 

Vanadium(V) oxide is amphoteric, dissolving in alkali to give salts of tetrahedral VO " anion, and in acid to give V02. The latter cation is almost certainly cis-[V02(H20)4]+, as in [V02(ox)2]3- and [V02(edta)]3 (ox = oxalate dianion edta = ethylenediamine tetraacetate tetraanion). All dioxo complexes of d° metals have cis configurations, an arrangement that maximizes dji-pjt interactions. 

This synthesis was carried out by reaction of polyethylene terephthalate and ethylenediamine in the presence of the metallic salts. Mechanical activation was supplied by vibratory milling in a nitrogen atmosphere. Granular polyethylene terephthalate (supplied by U.F.S.-Jassy) was subjected to mechanical processing in powdered form. It was purified by dissolving in a 40/60 phenol/chloroform mixture and reprecipitating with methanol. After filtration, the polymer was extracted... 

Solvated electrons in ammonia are formed in equilibrium with metal ions dissolved in this medium (76). Analogous behavior was reported for ethylenediamine (42). On mixing ethylenediamine solutions of alkali metals with water, hydrated electrons were claimed to he formed as transients (43). 

A much improved method involves the treatment of [Cr(H20)6]Cl3 dissolved in methanol with ethylenediamine, in the presence of a small piece of zinc metal. The function of the zinc (virtually all of which can be recovered unchanged at the end of the reaction) is to produce a catalytic amount of Cr(II). The zinc dissolves very slowly ... 

To a considerable extent, solutions of alkali metals in solvents such as methylamine or ethylenediamine exhibit similar properties to the ammonia solutions. Some of the alkali metals also dissolve in ethers and tetrahydrofuran, but that chemistry will not be described here. 

Reaction of group 15 elements like arsenic with alkali or alkaline earth metals forms Zintl anions of the general type Asn". Characterization of these species has been accomplished dissolving the solids in liquid NH3 or ethylenediamine (H2NCH2CH2NH2) and adding the macrocycle, 2,2,2-crypt (5) to complex the cations and stabilize the polyatomic anions. The fully characterized Zintl arsenic anions As4, As and Asu are shown inFigme 1. ... 

Metal ions have recently been used to direct the course of these condensation reactions. These template syntheses are the topic of a recent review by Busch (13). The compound shown in Figure 3(b), having square planar geometry, is one of the products formed by dissolving bis-(ethylenediamine)-nickel(II) perchlorate in acetone. 

Chromium metal (26.0 g, 0.50 mol) was dissolved in 4M HCl (240 mL, 0.96 mol) under a Nj atmosphere to give a blue solution of CrClj. After 4 h, when evolution of H2 had ceased and most of the metal had dissolved, a solution of l,5,6,7-tetrachloro-8,8-dimethoxy-c rfo-tricyclo[3.2.1.0 ]oct-6-ene (12.16g, 0.040 mol) and ethylenediamine (120 g, 2.0 mol) in DMF (800 mL) was added dropwise and the mixture was stirred magnetically for 36 h under Nj. The maroon-colored mixture was then poured into HjO and the product extracted into EtjO (3 x lOOmL). The combined EtjO extracts were washed thoroughly with HjO, dried, and evaporated to give a clear oil, which solidified when cooled to — 10°C. The solid was crystallized from pentane (at — 20°C) to give the product as chunky white crystals mp 22.5-23.5°C. 

Bis(ethylenediamine)copper(II) iodide has been prepared by passing air through a mixture of ethylenediamine and copper(I) iodide heated at 60°.5 Iodocuprate(I) compounds have been obtained by dissolving copper(I) iodide in concentrated alkali metal or ammonium iodide solutions. Bis(ethylenediamine)copper(II) diiodocuprate-(I) could be obtained by combining its components, but an adaptation of the procedure of Harris,3 as given here, obviates isolation of the bis(ethylenediamine)copper(II) ion and is somewhat more rapid. 

The anhydrous nitrates are voluminous, powdery solids, with colors comparable to those of the metal ions present. They dissolve rapidly and completely to clear solutions in water, ethanol, or anhydrous ethylenediamine. In contact with moist air they absorb water readily and give the corresponding hydrated salts. 

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