Ritter reaction metallic reagents

Earlier mention has been made of the use of Lewis acid and Friedel-Crafts reagents as initiators of carbenium ion formation. Another versatile device is to employ a metal to assist in generation of the carbenium ion. In its simplest form, addition of silver(I) ion to an alkyl halide is an excellent technique for encouraging reaction by means of the 5n 1 pathway. This process was first applied to the Ritter reaction by Cast and Stevens, but yields obtained were modest. A recent elegant application of this technique is the two-step conversion of dodecahedrane into its acetamide derivative (Scheme 45). ... 

Sodium superoxide in DMSO is a useful reagent for converting nitriles into amides. Isolated yields are above 70% for this reaction, which was unexpected as nitriles are inert to Na02 in other solvents. The mechanism is not completely understood. The Ritter-type synthesis of N-alkyl-amides from nitriles and alcohols can be improved by the addition of metal carbonyls to help stabilize the intermediate carbonium ions, and an alternative approach is to treat a nitrile with an alkyl halide and nitrosonium hexafluorophosphate. ... 

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