Cyanide-based compounds

To give but a few examples, up until today, chlorine and phosgene are used on a large scale as industrial chemicals in a variety of applications. Phosgene for example is used in the manufacture of aniline dyes, polycarbonate resins, coal tar, pesticides, isocyanates, polyurethane, and pharmaceuticals. 32 Current industrial operations utilizing cyanide-based compounds include ... 

Ethyl carbamate, C2HyN02, is developed naturally during the fermentation of alcohoHc beverages. It also appears in foods such as bread and yogurt. Since ethyl carbamate is not easily distilled, its formation most likely involves a distillable precursor. The mechanism of ethyl carbamate formation probably involves cyanate produced from the oxidation of cyanide or from urea-based compounds in the beer. Cyanate reacts with alcohol to form ethyl carbamate as follows ... 

Enkephalins with Tyr1 restrained within the skeleton of a benzomorphan have been reported by two groups. Ramakrishnan and Portoghese<171) prepared antipodal forms of the regioisomeric derivatives 19a and 19b by routes based on corresponding 1- and 3-cyanides. All compounds... 

Derivation (1) From propylene oxygen and ammonia with either bismuth phosphomolybdate or a uranium-based compound as catalysts (2) addition of hydrogen cyanide to acetylene with cuprous chloride catalyst (3) dehydration of ethylene cyanohydrin. 

In the last 10 years, considerable amount of research has been devoted to the development of heterodinuclear cyano-bridged cubic cluster based on the [Feni(Tp)(CN)3]- synthon which directs the formation of cyanide-bridged compounds with interesting structures and magnetic properties. 

A solvent-free reductive amination protocol for carbonyl compounds using sodium borohydride supported on moist montmorillonite KIO clay is facihtated by MW irradiation (Scheme 2.2-44) [129]. Traditionally, sodium cyanoborohydride [130], sodium triacetoxyborohydride [131], and NaBH4 coupled with sulfuric acid [132] are reagents used for the reductive amination of carbonyl compounds the use of corrosive acids or cyanide-based reagents results in toxic-waste generation. The... 

In this paper, we present the metastable a-polymorph of strontium carbodiimide as a novel pseudochalkogenide host lattice for divalent europium ions. Because of the high thermal inertness and cationic nitrogen coordination of this compound looks like a promising candidate for future applications. Furthermore, Sr-based compounds are ideal host lattices for divalent rare-earth-ions, simply because Sr " " is spectroscopically inactive, and Sr and Eu have comparable ionic rachi and identical charge. As a synthetic challenge, however, the preparation of phase-pure samples is required. Inspired by the reaction of EuN, BN, and NaN3 to form Eu3(NBN)2, and the synthesis of In2.24(NCN)3 from InBr and NaCN, we developed a new flux route based on the metal halide, alkaline cyanide, and alkaline azide, which act as precursors for the synthesis of structurally rather complex rare-earth and alkaline-earth cyanamides and... 

In 1990 Alper and Lee reported on a cobalt-catalyzed carbonylation of aryl iodides and alkyl iodides [293, 294]. In the presence of cobalt chloride or acetate, potassium cyanide, base, and PEG-400, carboxylic acids were produced from the corresponding iodo compounds. Lewis acids, such as boron trifluoride etherate... 

The valence states of most inorganic compounds can be changed by either cathodic reduction or anodic oxidation. Thus in principle appropriate species can be either recycled electrochemically or converted to less toxic and environmentally acceptable forms. Sulphur and nitrogen based compounds are thus typically encountered. For example the reduction of nitrates and nitrites and the oxidation of sulphur compounds, such as sulphite, thiosulphate and dithionite, can be carried out quite effectively. There are several established technologies for cyanide and chromium species. 

R. K. Pandey, N. James, Y. Chen and M. P. Dobhal, Cyanide Dye-Based Compounds for Tumor Imaging with and without Photodynamic Therapy , in Topics in Heterocyclic Chemistry, ed. L. Strekowski, Springer GmbH, 2008, vol. 14, Heterocyclic Pol5methine Dyes, p. 41. 

Cyanide-bridged compounds based on Prussian blue... 

The most general methods for the syntheses of 1,2-difunctional molecules are based on the oxidation of carbon-carbon multiple bonds (p. 117) and the opening of oxiranes by hetero atoms (p. 123fl.). There exist, however, also a few useful reactions in which an a - and a d -synthon or two r -synthons are combined. The classical polar reaction is the addition of cyanide anion to carbonyl groups, which leads to a-hydroxynitriles (cyanohydrins). It is used, for example, in Strecker s synthesis of amino acids and in the homologization of monosaccharides. The ff-hydroxy group of a nitrile can be easily substituted by various nucleophiles, the nitrile can be solvolyzed or reduced. Therefore a large variety of terminal difunctional molecules with one additional carbon atom can be made. Equally versatile are a-methylsulfinyl ketones (H.G. Hauthal, 1971 T. Durst, 1979 O. DeLucchi, 1991), which are available from acid chlorides or esters and the dimsyl anion. Carbanions of these compounds can also be used for the synthesis of 1,4-dicarbonyl compounds (p. 65f.). 

Mild acid converts it to the product and ethanol. With the higher temperatures required of the cyano compound [1003-52-7] (15), the intermediate cycloadduct is converted direcdy to the product by elimination of waste hydrogen cyanide. Often the reactions are mn with neat Hquid reagents having an excess of alkene as solvent. Polar solvents such as sulfolane and /V-m ethyl -pyrrol i don e are claimed to be superior for reactions of the ethoxy compound with butenediol (53). Organic acids, phenols, maleic acid derivatives, and inorganic bases are suggested as catalysts (51,52,54,59,61,62) (Fig. 6). 

A cyanohydrin is an organic compound that contains both a cyanide and a hydroxy group on an aUphatic section of the molecule. Cyanohydrias are usually a-hydroxy nitriles which are the products of base-cataly2ed addition of hydrogen cyanide to the carbonyl group of aldehydes and ketones. The lUPAC name for cyanohydrias is based on the a-hydroxy nitrile name. Common names of cyanohydrias are derived from the aldehyde or ketoae from which they are formed (Table 1). 

Production of cyanohydrins is accompHshed through the base-cataly2ed combination of hydrogen cyanide and the carbonyl compound in a solvent, usually the cyanohydrin itself (17). The reaction is carried out at high dilution of the feeds, at 10—15°C, and pH 6.5—7.5. The product is continuously removed from the reaction 2one, cooled to push the equilibrium toward cyanohydrin formation, and then stabili2ed with mineral acid. Purification is usually effected by distillation. 

KCN, 95% EtOH, 20° to reflux, 12 h, 93% yield.Potassium cyanide is a mild transesterification catalyst, suitable for acid- or base-sensitive compounds. When used with 1,2-diol acetates hydrolysis proceeds slowly until the first acetate is removed. ... 

Trimethylsilyl cyanide. This reagent readily silylates alcohols, phenols, carboxylic acids, and, more slowly, thiols and amines. Amides and related compounds do not react with it. The reagent has the advantage that a volatile gas (HCN is highly toxic) is the only by-product. In the following case, the use of added base resulted in retro aldol condensation ... 

Hydrogen cyanide, mp —13.3° bp 25.7°, is an extremely poisonous compound of very high dielectric constant (p. 55). It is miscible with H2O, EtOH and Et20. In aqueous solution it is an even weaker acid than HE, the dissociation constant Ka being 7.2 x 10 ° at 25°C. It was formerly produced industrially by acidifying NaCN or Ca(CN)2 but the most modem catalytic processes are based on direct reaction between... 

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