Synthesis of Pharmacologically Important Peptidomimetics

A potentially useful synthetic extension in this area of research has been the Passerini reaction-amine deprotection-acyl migration (PADAM) sequence, first conceived as a tool for giving access to peptide-like structures [40] and mainly developed by Banfi, Riva, and coworkers [2a]. In this sense, PADAM sequence has been employed for the synthesis of interesting peptidomimetics since the resulting a-ketoamide scaffolds are useful for drug discovery [41] or in the synthesis of enzyme inhibitors [42], and this amplifies the scope of this valuable multicomponent process [43] (Fig. 8.4). 

The general mechanism for a PADAM reaction involves a first condensation between N-Boc-protected a-aminoalde- 

The authors reasoned that the appropriate selection of the aldehyde 55, isonitrile 56, and carboxylic acid 57 fragments 

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