Formation and reaction

Both potassium and sodium cyanide react with alkyl halides to give excellent yields of the nitrile in the solvent DMSO. When the reaction is done in refluxing alcohol or when certain other metal cyan-ides are used, an isomeric product (see 4) is often observed called an isonitrile (isocyanide). Isonitriles were first reported 

Chapter 8. Nucleophilic Species That Form Carbon-Carbon Bonds 

Isonitriles can be used for a few useful synthetic transformations. The Passerini reaction is a convenient route to amide esters. When propionic acid was heated with acetone and fcrt-butylisonitrile, for example, the product was a-propanoyloxy amide 9. A useful modification of the Passerini reaction used trifluoroacetic acid rather than a normal aliphatic carboxylic acid. When a-phenoxyacetaldehyde (10) reacted with fcrf-butylisonitrile and trifluoroacetic acid (TFA), 11 was formed. Hydrolysis of this trifluoroacetyl ester with aqueous sodium carbonate led to isolation of the a-hydroxyamide (12) in 69% yield. This modification has the advantage that hydrolysis conditions for trifluoroacetate esters are milder than for normal esters. 

Isonitriles are somewhat limited in their synthetic utility, but they have some interesting disconnections  

Organometallic Chemistry of the Main Group Elements, ACS, Washington 1970, Cassettes 1/5, pp. 1/155. 

Haiduc, I. I., The Chemistry of Inorganic Ring Systems, Pt. 1/2, Wiley-Interscience, New York 1970, pp. 1/662, 1/575. 

Neumann, W. P., Recent Developments in the Field of Organic Derivatives of Group IV B Elements, Pure Appl. Chem. 23 [1970] 433/46. 

Alkali Metal and Magnesium Derivatives of Organo-Silicon, -Germanium, -Tin, -Lead, -Phosphorus, -Arsenic, -Antimony and -Bismuth Compounds, Organometal. Chem. Rev. A 6 [1970] 283/318. 

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The product of this reaction as its sodium salt is called a Meisenheimer complex after the Ger man chemist Jacob Meisenheimer who reported on their formation and reactions in 1902 A Meisenheimer complex corresponds to the product of the nucleophilic addition stage in the addition-elimination mechanism for nucleophilic aromatic substitution... 

Ma.nufa.cture. Nickel carbonyl can be prepared by the direct combination of carbon monoxide and metallic nickel (77). The presence of sulfur, the surface area, and the surface activity of the nickel affect the formation of nickel carbonyl (78). The thermodynamics of formation and reaction are documented (79). Two commercial processes are used for large-scale production (80). An atmospheric method, whereby carbon monoxide is passed over nickel sulfide and freshly reduced nickel metal, is used in the United Kingdom to produce pure nickel carbonyl (81). The second method, used in Canada, involves high pressure CO in the formation of iron and nickel carbonyls the two are separated by distillation (81). Very high pressure CO is required for the formation of cobalt carbonyl and a method has been described where the mixed carbonyls are scmbbed with ammonia or an amine and the cobalt is extracted as the ammine carbonyl (82). A discontinued commercial process in the United States involved the reaction of carbon monoxide with nickel sulfate solution. 

Pigment Red 144 [5280-784] 20735 disa2o condensation coupling of dia2oti2ed 2,5-dichloroaniline with 3-hydroxy-2-napthoic acid, foUowed by acid chloride formation and reaction with 2-chloro-/)-phen5iene- diamine... 

Above 160°C it is believed that additional cross-linking reactions take place involving the formation and reaction of quinone methides by condensation of the ether linkages with the phenolic hydroxyl groups (Figure 23.14). 

Hawkins, E.G.R. Organic Peroxides - Their Formation and Reactions Van Nostrartd Princeton, 1961. 

The catalytic conditions (aqueous concentrated sodium hydroxide and tetraalkylammonium catalyst) are very useful in generating dihalo-carbenes from the corresponding haloforms. Dichlorocarbene thus generated reacts with alkenes to give high yields of dichlorocyclopropane derivatives,16 even in cases where other methods have failed,17 and with some hydrocarbons to yield dicholromethyl derivatives.18 Similar conditions are suited for the formation and reactions of dibromocar-benc,19 bromofluoro- and chlorofluorocarbene,20 and chlorothiophenoxy carbene,21 as well as the Michael addition of trichloromethyl carbanion to unsaturated nitriles, esters, and sulfones.22... 

These hydroxyquinoxalines may be considered as regular alcohols or phenols because their formation and reactions are negligibly affected by the heterocyclic system or its nuclear substituents. 

Formed by either process, carbocations are most often short-lived transient species and react further without being isolated. The intrinsic barriers to formation and reaction of carbocations has been studied. ... 

For a review of the formation and reactions of xanthates, see Dunn, A.D. Rudorf, W. Carbon Disulphide in Organic Chemistry Ellis Horwood Chichester, 1989, p. 316. 

C2H5)2CCH3]Co(C,H5) Formation and Reaction with (C2H5)2C2B2(CH3)2CH2 6.5.3.1, 6.5.3.3... 

The formation and reaction of peroxyl radicals derived by reaction of tervalent phosphorus compounds with oxygen have attracted interest. Photolysis of trialkyl phosphites in oxygenated solutions of aromatic hydrocarbons gives phenols. " Phosphorus trichloride reacts with 1,2-dichloroethylene, in the presence of oxygen, to give (17). It is tempting to suggest that both reactions occur via similar intermediates, e.g. (15) and (16). 

Reactive intermediates in solution and in the gas phase tend to be indiscriminant and ineffective for synthetic applications, which require highly selective processes. As reaction rates are often limited by bimolecular diffusion and conformational motion, it is not surprising that most strategies to control and exploit their reactivity are based on structural modihcations that influence their conformational equilibrium, or by taking advantage of the microenvironment where their formation and reactions take place, including molecular crystals. ... 

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