Quaternized amhophosphines: A stable and convenient entry to valuable catalysts

The derivatization of aminophosphine ligands into their corresponding ammonium or ammonium-phosphonium salts with protic acids is reported. The resulting salts are, in general, much more tolerant of ambient conditions and represent convenient alternatives to the often highly air-sensitive unprotected ligands. The salts have been used to prepare transition metal complexes identical to those obtained from unprotected ligands by simple, in situ neutralization with base. These materials have also been found to be convenient synthons, affording a convenient alternate route to useful transition-metal catalysts when used in the absence of base.