Phosphonium ions reductive cleavage

Sodium-naphthalene reduction of organotrineopentoxyphosphonium salts led to the instantaneous loss of phosphonium ion phosphonates and phosphites were obtained748 (reaction 224). Alkali metal amalgams are efficient reagents for the reductive cleavage of both achiral and optically active phosphonium salts configuration is retained750 (Table 23). 

The C—P bond cleavage processes responsible for the observed interchange has been described in the literature. Novak and coworkers reported on the reversible formation of tetraarylphosphonium ion, via a reductive elimination pathway, as a possible key intermediate in the exchange of aryl groups on the central palladium with aryl groups on the phosphine moiety (Scheme 4.4) [5]. A subsequent oxidative addition of a different C-P bond in the phosphonium ion to the intermediary palladium(O) complex would then create the interchanged arylpaUadi-um(II) complex also observed by Chernard and coworkers [6]. A similar C-P bond... 

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