Journal of OrganometalIic Chemistry c47
Elsevier Sequoia S.A., Lausanne - Printed in The Netherlands
Preliminary communication
Reactivity of the metal coordinated ally1 ligand
I. A simple route to the preparation of tris(triphenylphosphine)- and
tris(tiphenylphosphite)palladium(O)
W. KURAN* and A. MUSCO
Istituto di mimica delle Macromolecole. Via A. Corti. 12 - 20133 Milan0 (Italy)
(Received May lst, 1972;in revised form May 25th, 1972)
The attack of nucleophilic agents containing OH and NH groups on an allylic
carbon atom of n-ally1 complexes is thought to play an important role in the
telomerization reactions of 1,3-dienes catalyzed by palladium complexes’.
As a part of a research program on the mechanistic aspect of these reactions, we
are currently investigating the nucleophilic attack at the allylic carbon atoms of some
phosphine- and phosphite-containing n-allyl-palladium complexes. In the course of our
investigation we have found that the action of nucleophiles on the cationic species
[n-ally&Pd(PR,)J + (PR, = P(C6H&, P(OC6H5)3) constitutes an easy route to the
preparation of the otherwise not easily accessible Pd [P(C,H,),] 3* and
Pd[P(OC,H,),] 3_ A typical preparation of these zerovalent palladium complexes is as
follows.
The phosphorous ligand (2 moles) was added to a methylene chloride solution of
(7r-methallyl-PdCQ2 (OS moles), benzylamine (1 S-2 moles) was then added to the mixture_
After a few minutes benzylarnine chlorohydrate (2/3 of mole) separated out, the methylene
chloride was evaporated, the residue washed with heptane and finally extracted with
toluene.
The heptane solution was found to contain N-methallyl- and NJV-
dimethallylbenzylamine. Pd [P(C,H,),] 3 and Pd [P(OC,H,),] 3 crystallized respectively as
yellow and very pale yellow, almost white, crystals from the toluene solution. The yields
based on palladium used were 40-50%. Both complexes are air sensitive especially in
solution. The analytical data are shown in Table I_
*On leave of absence from the Institute of Organic Chemistry and Technology, Technical University
Pohtechnika), Warsaw (Poland).
L
Pd[P(C,H,),] t has been isolated by Smutny and Chung from the Pd system which catalyses the
degradation of phenoxyoctadiene to phenol and octatriene=. The complexes [@-XC,HJ,P] ,Pd
(X = CH,, Cl) have been reported by Malatesta and Angoletk?.
J. Organometal. Chem., 40 (1972)
C48 PRELLMINARY COMMUNICATION
TABLE 1
ANALYTICAL DATA
Analysis found (calcd. J %
Mol. wt. foun@ M.P_~
C H P Pd (calcd.) PC)
WW,$V,I, 72.23 5.25 9.83 11.86 783 (893) 190-203 (dec)
(72.61) (5.08) (10.40) (11.91)
PdJP(OC,H,), 1, 61.78 4.51 8.34 11.22 921 (1037) 118-129 (dec)
(62.53) (4.37) (8.96) (10.26)
aCryoscopic determination in benzene under argon on samples crystallized from benzene-heptane
(samples crystallized from toluene have given lower values of the molecular weights for trapping of
the solvent in the crystals).
bUnder argon. The m-p. is only approximate, depending on the rate of heating.
The molecular weights of Pd[P(C,H&] 3 and Pd[P(OC,H&] 3 have been
determined by cryoscopy in benzene under argon. The results suggest that, within the
experimental error, both complexes show little dissociation in solution, thus
Pd[P(C,&)J s must appear to behave in solution as does Pt[P(C,H,),] j, for which only
slight dissociation to Pt[P(C,Hs),] 2 has been found4. The extension of the above
mentioned reaction to the preparation of other phosphine-palladium(O) complexes is
being investigated.
REFERENCES
1 W. Keim, ~AllyL System in Gztalysk in G.N. Schrauzer (Ed.), Transition Metals in Homogeneous
Catalysis, Marcel Dekker, New York, N.Y., 1971, p. 59.
2 E.3. Smutny and H. Chung, Amer. Chem. Sot_, Div. Petrol. Chem., Prepr_,.lh (1969) B112.
3 L. Malatesta and M. Angoletta, J. Chem. Sot., (1957) 1186.
4 J.P. Birk, J. Halpem and A.L. Picka.rd,fnorg. Chem,, 7 (1968) 2672.
J. OrganometaL Chem., 40 (1972)
