Triaryl arsines, oxidation

Conversion of aliphatic and aromatic amine N-oxides to corresponding amines, phosphine oxides to phosphines and triaryl arsine oxides to triaryl arsines have also been achieved. These reactions require the presence of HMPA as cosolvent (Zhang and Lin, 1987). 

Eq. (5.186)], triaryl arsines, and triaryl stibines react with nitronium salts to give the corresponding oxides. 

Trialkyl- and triaryl-phosphines, -arsines and -stibines are all good donors toward rf-group transition metals and chelating di- and tri-phosphines and -arsines have been especially widely used as 7r-acid ligands (Section 22-13). The oxides, R3MO, also form many complexes, but they function simply as donors. Trialkyl- and triaryl-phosphines, -arsines and -stibines generally react with alkyl and aryl halides to form quaternary salts ... 

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