Re: ORGLIST: tetrakis(triphenylphosphyne)palladium(0)

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From: Marko Hapke (marko.hapke$##$mail.uni-oldenburg.de)
Date: Mon Jan 22 2001 - 11:03:48 EST


Hi Valentine,

the compound can easily be made after the procedure given by D. R.
Coulson, Inorg. Synth., 1990, 121-124. I prepared it myself and
identified it with 31P-NMR and melting point:
31P-NMR: 16.3 ppm in toluen-d8 (85% H3PO4 as reference); M. R. Mason and
J. G. Verkade (Organometallics 1992, 11, 2212-2220) have done it in
CD2Cl2 with 15.5 ppm. Often you find a signal at 25.5 ppm, even in fresh
produced batches; this corresponds to the Phosphinoxid O=PPh3.
My melting point (under Argon): 105 C (Lit.(from D. R. Coulson):
105-110 C)

The compound can be handled in air for short periods but must be stored
under argon or nitrogen. If you have an old batch it could be useful to
check its catalytic activity in a standard reaction. The reason for the
lost of catalytic activity are not clear yet. An alternative is the
preparation in situ from Pd2(dba)3 and 4 equivalents PPh3.

Hope this will be useful
Marko



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