Oxidation-Reduction Condensation a New Method for Peptide Synthesis

Organic trivalent phosphorous compounds such as trialkyl phosphites and trialkyl or triarylphosphines are well known to be powerful deoxygenation reagents and have been used in various reduction reactions. But, it is rather a new aspect to make use of their property of deoxygenation for the gsneration of active acyl groups. Since the discovery of the rezcticn of mercuric acetate with trivalent phosphorous coqounds to yield acetic anhydride, our attention has been fccused on the generation of acyl groups and several novel reactions have been found which are applicable to the preparation of acid anhydride and peptide linkages. In considering these reactions described herein, it is necessary to choose appropriate oxidation reagents together with reducing reagents (trivalent phosphcrous compounds) because these dehydration reactions essentially proceed via an oxiaation reduction process as depicted in the following scheme.