HCN, reaction with

Tile a-dithione 158 (dithiete 159) underwent a [4 + 2] cycloaddition with fra s-(l,2-dimethoxy)ethylene to give 197 in addition to reactions with HCN and CH2N2, which yielded 198 and 199, respectively (74JA3502). 

Aldehydes and unhindered ketones undergo a nucleophilic addition reaction with HCN to yield cyanohydrins, RCH(OH)C=N. Studies carried out in the early 1900s by Arthur Eapworth showed that cyanohydrin formation is reversible and base-catalyzed. Reaction occurs slowly when pure HCN is used but rapidly when a small amount of base is added to generate the nucleophilic cyanide ion, CN. Alternatively, a small amount of KCN can be added to HCN to catalyze the reaction. Addition of CN- takes place by a typical nucleophilic addition pathway, yielding a tetrahedral intermediate that is protonated by HCN to give cyanohydrin product plus regenerated CN-. 

Amino acid formation in the Urey-Miller experiment and almost certainly in the prebiotic environment is via the Stecker synthesis shown in Figure 8.3. This reaction mechanism shows that the amino acids were not formed in the discharge itself but by reactions in the condensed water reservoir. Both HCN and HCO are formed from the bond-breaking reactions of N2 and H2O in a plasma, which then react with NH3 in solution. The C=0 group in formaldehyde or other aldehydes is replaced by to form NH and this undergoes a reaction with HCN to form the cyano amino compound that hydrates to the acid. The Strecker synthesis does not provide stereo-control over the carbon centre and must result in racemic mixtures of amino acids. There is no room for homochirality in this pathway. 

Cyclohexaamylose-N-methylacetohydroxamic acid, preparation of, 23 254 Cyclohexadienes, 20 293 reaction with HCN, 33 19, 20 on silica, reactions of, 34 54-56-34 64 cracking, 34 55, 72 vibrational spectra, 42 243 Cyclohexadienyl radicals, ESR of, 22 300 1,4-Cyclohexanediols, conversion of ethers, mechanism, 35 361-364 Cyclohexanes, 33 101, 102, 103 autoxidauon of, 25 303 conformational analysis of, 18 9-17 dehydrogenation, 31 14, 21-22 benzene accumulation over platinum, 36 18... 

Cyclopentadiene reaction with HCN, 33 19, 20 vibrational spectra, 42 243 Cyclopentane... 

Hexadiene-3-ol, hydrogenation, 30 361 Hexadiene, reaction with HCN, 33 19-20 Hexafluoropropene oxide oligomers, 42 497 Hexahydronaphthalenes, intermediates of naphthalene hydrogenation, 18 32, 33... 

The measured voltage was —0.440 V. Calculate the molarity of the KOH solution. Assume that essentially all coppeifl) is Cu(CN)2. A little HCN comes from the reaction of KCN with HA. Neglect the small amount of HA consumed by reaction with HCN. For the right half-cell, the reaction is Cu(CN)2 + e Cu(.v) + 2CN. ... 

A drawback connected with the tendency of Ni(0) to undergo oxidative addition of HCN is the formation of inactive nickel cyanide complexes. Such inhibition can be overcome, however, by keeping the HCN concentration low. This also has the further advantage of preventing sudden temperature increases arising from the high exothermicity of the reactions with HCN. 

Reaction with HCN at normal temperatures leading to the formation of other cyanides (SlottaandTschesche, 1927). 

Reaction with HCN 1.10.5.3 Reaction with phthalimide 1.10.5.5.1 Reaction with saccharin 1.10.5.5.1 Reaction with succinimide 1.10.5.5.1... 

Orthocarbonates and their analogs do exchange just one alkoxy group with TMS-CN/SnCU (Scheme 17). In earlier pt rs even the direct reaction with HCN and ZnCb at room temperature was reported to give (after several days or even some weeks) high yields. Treatment with acetyl cyanide (Scheme 17) represents another possibility for transforming orthoesters into bisalkoxynitriles. ... 

Alkynes are readily hydrocyanated in the presence of a homogeneous catalyst, especially a nickel-based catalyst system. However, zerovalent palladium compounds are reported to catalyze the reaction as well, but are less efficient [60], The reaction gives an easy access to the synthetically valuable a,P-un-saturated nitriles. The use of acetone cyanohydrin as a synthetic equivalent for the difficult-to-handle HCN provides an efficient alternative, but the substrate/ catalyst ratio has to be increased in comparison with the reaction with HCN. The regioselectivity of the reaction is controlled by steric, electronic, and chelative effects. Investigations were predominantly performed by changing the substituent pattern on the acetylenic substrate [61]. 

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