Oximes to nitriles

Irradiation of a mixture of androstane (28) and cholestane (29) followed by oxidation of the product oximes to nitriles and mass spectrometric analysis revealed a N15/N14 ratio of 1 1.32 for the product derived from (28) and a N16/N14 ratio of 1 1.25 for the product derived from (29). Thus mechanism (a) is effectively eliminated, see top of facing page. 

Imanaka—heterogenization of Rh complexes. In 1991, Imanaka and coworkers124 reported the heterogenization of Rh complexes by binding them to aminated polymers. As discussed previously, these findings led to fruitful research by Ford, Pardey, and others. The isolated polymer-bound Rh carbonyl anion complex was found to be reusable for reactions such as water-gas shift and reduction of nitro compounds. The polymer-bound Rh complexes were characterized by infrared spectroscopy. Water-gas shift activity (80 mol H2 per mol Rh6(CO)i6 in 24 hours) was recorded using the Rh complexes at 100 °C with 0.92 atm of CO, 2.16 ml H20, 0.05 mmol Rh6(CO)16, aminated polystyrene, 5.0 mmol of N, 5.56 ml ethoxyethanol and reduction of nitro-compounds (e.g., aliphatic nitro compounds to nitriles, oximes to nitriles, hydroxylamines to nitriles, and N-oxides to amines) occurred at 40 °C. 

Dehydration (cf., 6, 648). A reagent (1), prepared in situ from (C6H5),PO and Tf20 in the molar ratio 2 1, effects dehydration, usually at 25°, of amides or oximes to nitriles in >90% yield. It also effects condensation of acids and amines to form amides. The reaction of an aryl carboxylic acid with an o-phenylenediamine promoted by 1 provides 2-arylbenzimidazoles in >80% yield (equation I). If the... 

Dehydration. This reagent is useful for synthesis of acyl azides from carboxylic acids, NaCN, and pyridine, with tetrabutylammomum bromide as catalyst (75-95% yield). In combination with pyridine, it effects dehydration of oximes to nitriles in 80-90% yield, P-Lactams can be prepared directly in 40-75 )t yield from carboxylic acids and imines with the reagent (1 equiv,) and triethylamine (excess). In general, a mixture of cis- and rra/j5-azetidinones is formed. 

Dehydration.1 This reagent is useful for synthesis of acyl azides from carboxylic acids, NaCN, and pyridine, with tetrabutylammonium bromide as catalyst (75-95% yield). In combination with pyridine, it effects dehydration of oximes to nitriles in 80-90% yield. 

Miller, C. P., Kaufman, D. H. Mild and efficient dehydration of oximes to nitriles mediated by the Burgess reagent. Synlett 2000,1169-1171. 

Dehydration of oximes to nitriles with the reagent also has been reported. A solution of 0.05 mole of heptaldoxime and 5 drops of triethylamine in 30 ml. of benzene was treated with 0.1 mole of phenyl isocyanate in 10 ml. of benzene and lefluxed for 2 hrs. The carbon dioxide evolved was collected as BaCOs and cor-... 

BECKMANN Rearrangement or Fragmentation Acid catalyzed rearrangement of oximes to amides or cleavage of oximes to nitriles. 

Dehydration reactions using the tertiary phosphine-carbon tetrachloride adduct have appeared quite regularly in the literature again this year. Among those reported have been the dehydrations of oximes to nitriles, carboxylic acids to anhydrides, and the amides (37) to the cumulenes (38). Further reaction of the dehydration product from treatment of the... 

Conversion of oximes to nitriles. Aldoximes are converted into nitriles in high yield by treatment with an ortho ester in the presence of a catalytic amount of an acid (methanesulfonic acid). The primary product is the oxime dialkyl ortho ester, which can be isolated in the absence of the acid catalyst. ... 

Ahmad, A., and I.D. Spenser The Conversion of a-Keto Acids and of a-Keto Acid Oximes to Nitriles in Aqueous Solution. Canad. J. Chem. 39, 1340 (1961). 

Use as Dehydrating Agent. The reagent converts oximes to nitriles under mild conditions (rt, 1.5 h) (eq 1). ... 

The deoxygenation of the oxime to nitriles possibly proceeds according to Scheme 10 ... 

Oxyma [59, ethyl 2-cyano-2-(hydroxyimino)acetate] has been 0-sulfonated, and the sulfonate ester (60) is an excellent catalyst for dehydration of oximes to nitriles. ... 

Rogic, M.M., J.F. Van Peppen, K.P. Klein et al. 1974. New facile method for conversion of oximes to nitriles. Preparation and acid-catalyzed transformation of aldehyde oxime ortho esters. J Org Chem 39 3424—3426. 

Introduction. The Ph3PBr2 adduct was first used in synthesis in 1959 for the preparation of alkyl and acyl bromides from alcohols and carboxylic acids, and for the dehydration of amides and oximes to nitriles. Since then it has been widely employed as a versatile reagent for a number of synthetic reactions. 

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