Iron derivatives Subject

Pyrrolidone is the major product when allylamine is subjected to the conditions of the oxo process using dicobalt octacarbonyl as the catalyst.203 The by-products are pyridine derivatives 112 and 113 and these compounds become the major products when iron pentacarbonyl is used as the catalyst ... 

Combustion of transition metal organometallic compounds produces a mixtures of simple compounds (metal oxides, carbon oxides, water, nitrogen) which is subject to exact analysis. Thermal decomposition or high temperature iodination of the same compounds cannot necessarily be expected to produce simple materials, with the result that identification is often a difficult problem. This is typified by diene derivatives of iron carbonyl10, where side reactions of the dienes (e.g. polymerization) follow disruption of the iron-diene bonds. The oligomeric mixture can be parti-... 

All of the examples cited above involve monoacylation of iron-diene complexes. Frank-Neumann has recently demonstrated that monoacylated derivatives are subject to a second acylation and that bis-1,4-diacylated complexes could be obtained in moderate to good yields. Examples ate given in equations (8) and (9) and Table 4.20,23... 

Melanin granules are secreted by melanocytes in the hair papilla and distributed to keratin in the hair cortex and inner layers of the hair sheath during normal development. Melanogenesis is subject to hormonal control and has been the focus of intensive genetic studies. Two main forms of melanin exist in human skin—eumelanin and phaeomelanin, both of which are derived from tyrosine through the action of tyrosinase (a cupro-enzyme) and possibly other key enzymes (with nickel, chromium, iron, and manganese as cofactors). Tyrosine is converted to dihydroxyphenylalanine and, via a series of intermediate steps, to indole-5,6-quinone, which polymerizes to eumelanin. Phaeomelanins are produced by a similar mechanism but with the incorporation of sulfur (as cysteine) by a nonenzymatic step in the oxidation process. 

Baylis-Hillman adducts such as 55 and 56 derived from 2-nitrobenzaldehydes were shown to function as useful precursors to functionalized (1H)-quinol-2-ones and quinolines. Treatment of 55 and 56 with iron and acetic acid at 110 °C afforded 57 and 58, respectively <02T3693>. A variety of other cyclization reactions utilized in the preparation of the quinoline scaffold were also reported. An iridium-catalyzed oxidative cyclization of 3-(2-aminophenyl)propanols afforded 1,2,3,4-tetrahydroquinolines <02OL2691>. The intramolecular cyclization of aryl radicals to prepare pyrrolo[3,2-c]quinolines was studied <02T1453>. Additionally, photocyclization reactions of /rans-o-aminocinnamoyl derivatives were reported to provide 2-quinolones and quinolines <02JHC61>. Enolizable quinone and mono- and diimide intermediates were shown to provide quinolines via a thermal 6jt-electrocyclization <02OL4265>. Quinoline derivatives were also prepared from nitrogen-tethered 2-methoxyphenols. The corresponding 2-methoxyphenols were subjected to a iodine(III)-mediated acetoxylation which was followed by an intramolecular Michael addition to afford the quinoline OAc O... 

Ruthenium Dicarbonyl, Ru(CO)a.—Ruthenium, like iron, yields a carbonyl derivative. It is obtained as an orange-yellow deposit upon subjecting ruthenium black to the action of carbon monoxide at 300° C. under a pressure of 400 atmospheres. The product is extracted from the residue by solution in alcohol. It is insoluble in benzene and in hydrochloric acid, but soluble in nitric acid and in bromine, gas being evolved. When heated, a mirror of metallic ruthenium is produced.5 In contradistinction to the other carbonyls of this group of metals ruthenium dicarbonyl is not volatile. 

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