New methods for the synthesis of ArPdL2I (L = tertiary phosphine) complexes

Article abstract of DOI:10.1021/om9602567

Organopalladium ArPdL₂I (L = tertiary phosphine) complexes (1) can be synthesized in one step from the precursors Pd₂(dba)₃·C₆H₆ (2) (dba = t,t-dibenzylideneacetone) and (η³-allyl)PdCp (3) (Cp = η⁵-cyclopentadienide). Two advantages over previous synthetic methods are that this route requires only stoichiometric amounts of phosphine and that the desired complexes are easily isolated from reaction byproducts. The scope and generality of these reactions are investigated, and the synthesis of a number of new organic- and water-soluble complexes utilizing this methodology is discussed. Improved syntheses of water-soluble ligands P(C₆H₅)₂(4-SO₃KC₆H ₄) (5) and As(C₆H₅)₂(4-SO₃KC₆H ₄) (6) are presented as well.

Full text of DOI:10.1021/om9602567

3708
Organometallics 1996, 15, 3708-3716
New Meth od s for th e Syn th esis of Ar P d L2I (L ) Ter tia r y
P h osp h in e) Com p lexes
Thomas I. Wallow,† Felix E. Goodson, and Bruce M. Novak*
Department of Polymer Science and Engineering and the Materials Research Science and
Engineering Center, University of Massachusetts, Amherst, Massachusetts 01003, and
Department of Chemistry, University of California, Berkeley, California 94720
Received April 2, 1996X
Organopalladium ArPdL2I (L ) tertiary phosphine) complexes (1) can be synthesized in
one step from the precursors Pd2(dba)3‚C6H6 (2) (dba ) t,t-dibenzylideneacetone) and (η3-
allyl)PdCp (3) (Cp ) η5-cyclopentadienide). Two advantages over previous synthetic methods
are that this route requires only stoichiometric amounts of phosphine and that the desired
complexes are easily isolated from reaction byproducts. The scope and generality of these
reactions are investigated, and the synthesis of a number of new organic- and water-soluble
complexes utilizing this methodology is discussed. Improved syntheses of water-soluble
ligands P(C6H5)2(4-SO3KC6H4) (5) and As(C6H5)2(4-SO3KC6H4) (6) are presented as well.
In tr od u ction
ligands into cross-coupling polymerizations can result
not only in production of monofunctional aryl endcaps
but also produce branched network structures by inad-
vertent generation of multifunctional phosphine mono-
mers.6 Given this wide range of potential consequences,
a more detailed understanding of the aryl interchange
process would be useful.
Organopalladium complexes ArPdL2X (L ) tertiary
phosphine, X ) halide or sulfonate) play central roles
as catalytic intermediates in a broad spectrum of cross-
coupling reactions.1 These complexes provide an at-
tractive entry point into Pd-mediated cross-couplings,
due to both enhanced catalytic activity relative to
zerovalent PdLn complexes2 and ease of handling. Un-
like zerovalent PdLn compounds, ArPdL2X species are
stable in air for hours to days, depending on the specific
complex. A renewed interest in the stoichiometric
reactivity of ArPdL2X compounds has arisen following
the discovery that aryl moieties bound to the phospho-
rus atoms can interchange readily with the aryl group
bound to the palladium center (eq 1).3 This revelation
(2) Whether or not a uniform scale for ranking the catalytic efficiency
of Pd complexes exists in the context of cross-coupling remains an
incompletely resolved issue. Numerous authors have reported that
phosphine inhibition can play a role in limiting catalytic efficiency and/
or employ stoichiometrically matched (1:2 Pd:P), entirely “ligandless”,
or even heterogeneous catalyst precursors. See: (a) Reference 1c,g,h
and references therein. (b) Thompson, W. J .; J ones, J . H.; Lyle, P. A.;
Thies, J . E. J . Org. Chem. 1988, 53, 2052. (c) Majeed, A. J .; Antonsen,
O.; Benneche, T.; Undheim, K. Tetrahedron 1989, 45, 4. (d) San-
dosham, J .; Undheim, K. Acta Chem. Scand. 1989, 43, 684. (e) Farina,
V.; Krishnan, B. J . Am. Chem. Soc. 1991, 113, 9585 and references
therein. (f) Banwell, M. G.; Cameron, J . M.; Collis, M. P.; Crisp, G.
T.; Gable, R. W.; Hamel, E.; Lambert, J . N.; Mackay, M. F.; Reum, M.
E.; Scoble, J . A. Aust. J . Chem. 1991, 44, 705. (g) Ali, N. M.; McKillop,
A.; Mitchell, M. B.; Rebelo, R. A.; Wallbank, P. J . Tetrahedron 1992,
48, 8117. (h) Wallow, T. I.; Novak, B. M. J . Org. Chem. 1994, 59, 5034
and references therein. Alternatively, some reactions have been
reported to proceed more readily in the presence of Pd[P(C6H5)3]4 or
reaction mixtures containing excess phosphines. Use of these systems
is ubiquitous; see reviews in ref 1. Catalyst stability in the presence
of excess phosphines is sometimes invoked: some degree of catalyst
tailoring to complement the reactivity of a given substrate appears to
be necessary in instances when sterically hindered or complex multi-
functional substrates are used.
Control of Pd:ligand stoichiometry is frequently accomplished by
generating catalytic species in situ. For comprehensive discussions
of subtleties that pertain to such processes as well as extensive
compilations of methods employing in-situ generated catalysts; see:
(i) Amatore, C.; Azzabi, M.; J utand, A. J . Am. Chem. Soc. 1991, 113,
8375. (j) Amatore, C.; J utand, A.; Khalil, F.; M’Barki, M. A.; Mottier,
L. Organometallics 1993, 12, 3168.
(3) (a) Kong, K.-C.; Cheng, C.-H. J . Am. Chem. Soc. 1991, 113, 6313.
(b) Herrmann, W. A.; Brossmer, C.; Priermeier, T.; O¨ fele, K. J .
Organomet. Chem. 1994, 481, 97.
has potentially dramatic consequences for the synthesis
of small molecules and polymers4 utilizing palladium-
mediated cross-couplings. Several recent investigations
have attributed the formation of phosphine-derived
byproducts in palladium-mediated cross-coupling reac-
tions to this aryl-aryl interchange.5 Furthermore, our
own work suggests that incorporation of phosphine
* To whom correspondence should be addressed at the Department
of Polymer Science, University of Massachusetts.
† Current address: AT&T Bell Laboratories, 600 Mountain Ave,
Murray Hill, NJ 07974.
X Abstract published in Advance ACS Abstracts, August 1, 1996.
(1) For selected reviews, compilations, and monographs, see: (a)
Heck, R. F. Acc. Chem. Res. 1979, 12, 146. (b) Negishi, E. I. Acc. Chem.
Res. 1982, 15, 340. (c) Beletskaya, I. P. J . Organomet. Chem. 1983,
250, 551. (d) Heck, R. F. Palladium Reagents in Organic Syntheses;
Academic: London, 1985. (e) Stille, J . K. Angew. Chem., Int. Ed. Engl.
1986, 25, 508. (f) Trost, B. M. Angew. Chem., Int. Ed. Engl. 1989, 28,
1173. (g) Beletskaya, I. P. Bull. Acad. Sci. USSR, Div. Chem. Sci.
(Engl. Transl.) 1990, 39, 2013. (h) Undheim, K.; Benneche, T.
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Organomet. Chem. 1993, 457, 167. (l) Undheim, K.; Benneche, T. Acta
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1993, 44, 59. (b) Tour, J . M. Adv. Mater. 1994, 6, 190.
(5) (a) O’Keefe, D. F.; Dannock, M. C.; Marcuccio, S. M. Tetrahedron
Lett. 1992, 33, 6679. (b) Hunt, A. R.; Stewart, S. K.; Whiting, A.
Tetrahedron Lett. 1993, 34, 3599. (c) Segelstein, B. E.; Butler, T. W.;
Chenard, B. L. J . Org. Chem. 1995, 60, 12. Milstein has proposed that
substrate-dependent structural changes of phosphine ligands during
catalysis may complicate mechanistic investigations. (d) Milstein, D.
Chemtracts: Inorg. Chem. 1991, 3, 356. Similarly, studies by Ceriotti
et al. have demonstrated that an analogous ligand transformation via
alkyl-aryl interchange renders
a meaningful kinetic analysis of
cyclohexene hydroformylation by Rh-phosphine complexes impossible.
(e) Ceriotti, A.; Garlaschelli, L.; Longoni, G.; Malatesta, M. C.;
Strumolo, D.; Fumagalli, A.; Martinengo, S. J . Mol. Catal. 1984, 24,
309.
S0276-7333(96)00256-7 CCC: $12.00 © 1996 American Chemical Society

ArPdL2I Complexes
Organometallics, Vol. 15, No. 17, 1996 3709
In this paper, we describe highly general, flexible, and
functional-group-tolerant methods for synthesizing
ArPdL2I complexes (1). Such methods are necessary for
synthesizing the variety of compounds required for
substituent-effect studies of the aryl-aryl interchange
and mechanistic investigations of Suzuki aryl cross-
coupling reactions in aqueous media.7 We report that
the direct synthesis of ArPdL2I complexes using Pd2-
(dba)3‚C6H6 (2) (dba ) t,t-dibenzylideneacetone) and (η3-
allyl)PdCp (3) (Cp ) η5-cyclopentadienide) as precursors
provides high yields of the desired complexes from
stoichiometric mixtures of the precursors, aryl iodides,
and phosphines within minutes at room temperature.
By employment of stoichiometric amounts of reagents,
these routes minimize or eliminate the need for tedious
and often intractable purification problems that can
arise in traditional synthetic routes. Since these pre-
cursors are generic and tolerant of functional groups,
ArPdL2I complexes derivatized with nearly any combi-
nation of aryl moieties and substituted phosphines may
be synthesized in one step. Finally, we demonstrate
that 2 is a useful precursor for synthesizing water-
soluble ArPdL2I complexes in high yields. We note that
the methods presented here may represent a convenient
method for synthesizing chiral complexes,8 since only
stoichiometric amounts of potentially expensive phos-
phines are required.
In the course of mechanistic investigations on pal-
ladium complexes, several researchers have used aryl
iodides or electron-poor olefins to trap transient zerova-
lent “Pd(L)2” species.12 The similarity of this technique
to the reports of Ishii et al., who noted that Pd2(dba)3‚-
solvent (solvent ) C6H6 (2) or CHCl3) complexes un-
dergo a variety of ligand exchange and formal oxidative
addition reactions13 prompted us to consider 2 as a
direct precursor. Given the lability of 2 and the rapid
oxidative addition of aryl iodides to zerovalent pal-
ladium at room temperature,14 a one-step, direct syn-
thesis of ArPdL2I complexes from 2 seemed feasible (eq
5). Indeed, studies presented in this paper show that
addition of a stoichiometric mixture of an aryl iodide
and triarylphosphine to a solution of 2 gives a nearly
quantitative yield of the desired ArPdL2I complex in ca.
5-10 min at room temperature. Since our first pre-
liminary disclosure on the use of this methodology,2h
other researchers have used 2 as a precursor into
ArPdL2I (L ) triphenylarsine) complexes15 and (ArP-
dLBr)2 (L ) bulky phosphine) complexes.16b
Resu lts a n d Discu ssion
Syn th etic Meth od ology. Given the specific impor-
tance of ArPd[P(C6H5)3]2I complexes, there are surpris-
ingly few reports of synthetic alternatives to the tradi-
tional route involving oxidative addition of an aryl iodide
9
to zerovalent Pd[P(C6H5)3]4 (eq 2). One such alterna-
A second one-step procedure was developed using (η3-
allyl)PdCp (3) as a precursor (eq 6). Shaw has shown
tive involves the use of strong reducing agents (eq 3) to
form the desired complexes.10 Boersma et al.11 have
synthesized (C6H5)Pd)tmeda)I (tmeda ) N,N,N′,N′-
tetramethylethylenediamine) and reported it to be a
useful precursor to bis(triphenylphosphine) species via
ligand exchange reactions (eq 4). Treatment of the
tmeda complex with 2 equiv of P(C6H5)3 provided a 90%
yield of (C6H5)Pd[(P(C6H5)3]2I.
that 3 rapidly generates Pd[P(C6H5)3]4 in the presence
of excess P(C6H5)3.17 Upon addition of a stoichiometric
(12) For some examples, see: (a) Ozawa, F.; Ito, T.; Nakamura, Y.;
Yamamoto, A. Bull. Chem. Soc. J pn. 1981, 54, 1868. (b) Loar, M. K.;
Stille, J . K. J . Am. Chem. Soc. 1981, 103, 4174. (c) Ozawa, F.;
Kurihara, K.; Yamamoto, T.; Yamamoto, A. Bull. Chem. Soc. J pn. 1985,
58, 399. (d) Ozawa, F.; Fujimori, M.; Yamamoto, T.; Yamamoto, A.
Organometallics 1986, 5, 2144. (e) Ozawa, F.; Kurihara, K.; Fujimori,
M.; Hidaka, T.; Toyoshima, T.; Yamamoto, A. Organometallics 1989,
8, 180. (f) Reference 10b. (g) Mason, M. R.; Verkade, J . G. Organo-
metallics 1992, 11, 2212. (h) Grushin, V. V.; Alper, H. Organometallics
1993, 12, 1890. (i) Sakamoto, M.; Shimizu, I.; Yamamoto, A. Chem.
Lett. 1995, 1101. Also, see ref 2i,j.
(6) For preliminary disclosures, see: (a) Wallow, T. I.; Seery, T. A.
P.; Goodson, F. E.; Novak, B. M. Polym. Prep. (Am. Chem. Soc. Div.
Polym. Chem.) 1994, 35 (1), 710. (b) Novak, B. M.; Wallow, T. I.;
Goodson, F. E.; Loos, K. Polym. Prep. (Am. Chem. Soc. Div. Polym.
Chem.) 1995, 36 (1), 693.
(7) (a) Casalnuovo, A. L.; Calabrese, J . C. J . Am. Chem. Soc. 1990,
112, 4324. (b) Wallow, T. I.; Novak, B. M. J . Am. Chem. Soc. 1991,
113, 7411.
(8) de Graaf, W.; Boersma, J .; van Koten, G.; Elsevier, C. J . J .
Organomet. Chem. 1989, 378, 115.
(9) (a) Fitton, P.; J ohnson, M. P.; McKeon, J . E. J . Chem. Soc., Chem.
Commun. 1968, 6. (b) Fitton, P.; Rick, E. A. J . Organomet. Chem.
1971, 28, 287. (c) Eady, J . F. U.S. Patent 4 578 522, 1986. (d) Hill, J .
A.; Eady, J . F. J . Labelled Comp. Radiopharm. 1992, 31, 1011.
(10) (a) Negishi, E.; Takahashi, T.; Akiyoshi, K. J . Organomet. Chem.
1987, 334, 181. (b) Brown, J . M.; Cooley, N. A. Organometallics 1990,
9, 353.
(11) (a) de Graaf, W.; van Wegen, J .; Boersma, J .; Spek, A. L.; van
Koten, G. Recl. Trav. Chim. Pays-Bas 1989, 108, 275. (b) Markies, B.
A.; Canty, A. J .; de Graaf, W.; Boersma, J .; J anssen, M. D.; Hogerheide,
M. P.; Smeets, W. J . J .; Spek, A. L.; van Koten, G. J . Organomet. Chem.
1994, 482, 191.
(13) (a) Ukai, T.; Kawazura, H.; Ishii, Y. J . Organomet. Chem. 1974,
65, 253. (b) Ito, T. S.; Hasegawa, S.; Takahashi, Y.; Ishii, Y. J .
Organomet. Chem. 1974, 73, 401.
(14) (a) Fauvarque, J .-F.; Pflu¨ger, F.; Troupel, M. J . Organomet.
Chem. 1981, 208, 419. (b) Amatore, C.; Pflu¨ger, F. Organometallics
1990, 9, 2276.
(15) Morita, D. K.; Stille, J . K.; Norton, J . R. J . Am. Chem. Soc. 1995,
117, 8576.
(16) (a) Paul, F.; Patt, J .; Hartwig, J . F. J . Am. Chem. Soc. 1994,
116, 5969. (b) Paul, F.; Patt, J .; Hartwig, J . F. Organometallics 1995,
14, 3030. (c) Hartwig, J . F.; Paul, F. J . Am. Chem. Soc. 1995, 117,
5373. For other examples of oxidative addition reactions to coordina-
tively unsaturated palladium complexes bearing only a single tertiary
phosphine ligand, see: (d) Reference 12h. (e) Grushin, V. V.; Alper,
H. J . Am. Chem. Soc. 1995, 117, 4305. (f) Grushin, V. V.; Bensimon,
C.; Alper, H. Organometallics 1995, 14, 3259.
(17) Shaw, B. L. Proc. Chem. Soc. 1960, 247.

3710 Organometallics, Vol. 15, No. 17, 1996
Wallow et al.
Ta ble 1. Syn th esis of Or ga n ic-Solu ble Ar P d L2I
Com p lexes
Ta ble 2. Syn th esis of Ar P d L2I Com p lexes: Scop e
a n d Lim ita tion s
% yield
% yield
complex
X
Y
from 2
from 3
1a
1b
1c
1d
1e
1f
1g
1h
1i
1j
1k
1l
1m
1n
1o
1p
1q
1r
H
H
H
H
H
H
H
OCH3
OCH3
OCH3
OCH3
CH3
CH3
CH3
CH3
F
F
F
F
CF3
CF3
CF3
CF3
CF3
4-OCH3
4-CH3
4-F
4-NO2
4-CF3
2-CH3
2-OCH3
H
4-CH3
4-F
4-CF3
H
4-OCH3
4-F
4-CF3
H
4-OCH3
4-CH3
4-CF3
H
4-OCH3
4-CH3
4-F
90
87
95
94
89
95
99
95
97
98
94
85
87
93
53
91
89
78
90
89
86
1s
1t
1u
1v
1w
1x
35
73
56
80
20
77
F5
mixture of an aryl iodide and triphenylphosphine, 3 also
gives a nearly quantitative yield of the desired ArPdL2I
complex at room temperature. Recently, Yamamoto and
co-workers were able to synthesize ArPdL2I complexes
by oxidatively adding quaternary phosphonium salts to
Pd(methyl acrylate)(PMePh2)2 providing another viable
route to these compounds as well as some interesting
insights into the mechanism of the aryl-aryl exchange
reaction.12i However, the methodology from precursors
2 and 3 does have the important advantage of allowing
the single-step synthesis of a number of different
compounds containing a variety of ligands from a single
palladium starting material.
Scop e of Meth od ology. Representative syntheses
of several ArPdL2I complexes (1) were carried out using
both precursors; the results are summarized in Tables
1-3. In most cases (Table 1), complex 3 was the
preferred precursor as only volatile byproducts are
formed in the reaction, thus simplifying the purification
of the desired products. However, 3 was found to be
unreactive toward arsine-based ligands and was seen
to decompose rapidly in the presence of water-solubi-
lizing sulfonated phosphines. Consequently, for the
synthesis of water-soluble complexes (Table 3), oxidative
addition to precursor 2 was the preferred route.
as normal. When an aryl bromide was used in place of
an aryl iodide, the result was a complex mixture of
products from which the desired complex could not be
isolated. Steric bulk on the phosphine ligands also had
an adverse effect on the reactions, although ortho
substituents on the aryl iodide appeared not to affect
product formation. Hartwig has recently developed
syntheses of several dimeric arylpalladium halide com-
pounds with bulky phosphine ligands from a Pd0L2
precursor.16 Researchers in his group also attempted
to synthesize the bromide complexes directly from 2 but
similarly had difficulties in isolating pure complexes in
appreciable yields.16b The authors suggested that this
might be due to dibenzylideneacetone insertions and
subsequent â-hydrogen eliminations resulting in the
formation of HBr. Running these reactions in the
presence of triethylamine did produce pure complexes,
but the yields were still no higher than those obtained
from the Pd0L2 precursor.16b
Complexes 1a -f have been synthesized previously
(see Experimental Section); these are highly crystalline
materials which can be readily purified from byproducts
such as excess phosphines or dibenzylideneacetone.
Thus, the methods developed here do not provide any
special advantages over the known preparation of these
compounds from Pd[P(C6H5)3]4. For organic-soluble
complexes 1h -z, however, the analogous PdL4 species
are not known or are not readily accessible, due largely
to the expense or the nontrivial syntheses of the ligands.
As a result, the preparation of these new compounds is
made possible specifically by the methods described
above. Preliminary studies on the aqueous systems
showed the syntheses of complexes 1a a -ee via analo-
gous water-soluble PdL3 precursors7 to be unsatisfac-
Table 2 further illustrates the scope and generality
of these procedures. Although the chelating 1,3-bis-
(diphenylphosphino)propane ligand promoted the reac-
tion in the normal manner, 1,2-bis(diphenylphosphino)-
benzene failed to produce the target complex, presumably
because of sterics (vide infra). The bulky, electron-poor
perfluorotriphenylphosphine ligand also failed to yield
identifiable complexes in the presence of either precur-
sor. However, when tris(4-(trifluoromethyl)phenyl)-
phosphine was used as a ligand, the reactions proceeded

ArPdL2I Complexes
Organometallics, Vol. 15, No. 17, 1996 3711
Ta ble 3. Syn th esis of Wa ter -Solu ble Ar P d L2I Com p lexes
% yield
% yield
complex
Z
ligand
from 2
from 3
1a a
1bb
1cc
1d d
1ee
-3-CO2CH3
-4-CO2CH3
-4-CO2CH3
-4-NO2
P[(C6H5)3]2(3-SO3NaC6H4) (4)
P[(C6H5)3]2(4-SO3KC6H4) (5)
As[(C6H5)3]2(4-SO3KC6H4) (6)
5
5
94a
95a
84a
99
0
-4-CF3
99
a
Crude yield.
tory; the reactions went to completion, but as the
solubilities of the products matched those of the liber-
ated phosphines, purification of the complexes proved
to be difficult. Consequently, the stoichiometric proce-
dures presented in this paper provide a notable im-
provement in the synthesis of these compounds as well.
preparative routes used to generate potassium diphe-
nylphosphide and -arsenide. The most effective syn-
thesis of 5 employs chlorodiphenylphosphine in THF as
shown in eq 7, while 6 is more readily prepared from
Water soluble compound 1a a appears to be noncrys-
talline, and the removal of trapped solvents has proven
to be difficult. In order to overcome this problem, we
prepared more symmetric analogs. Substitution of
highly crystalline phosphine 5 in place of phosphine 4
and use of methyl 4-iodobenzoate as an aryl iodide
instead of the corresponding 3-isomer produced crystal-
line complex 1bb, which could be obtained in analytical
purity. Arsine complex 1cc and phosphine complexes
1d d ,ee were prepared in the same manner. Ironically,
neither 1bb nor 1cc is stable in unbuffered water for
more than approximately 30 min at room temperature,
due to apparent ester hydrolysis and subsequent acid-
promoted decomposition. Solutions prepared in aqueous
bicarbonate solution or methanol are stable for several
hours at room temperature and for days when stored
at -20 °C. Both complexes 1d d ,ee are water stable.
However, they are potent surfactants and are best
prepared as stock solutions in aqueous mixtures with
alcohols or acetone to suppress foaming.
Syn t h esis of P (C6H 5)2(4-SO3KC6H 4) (5) a n d
As(C6H5)2(4-SO3KC6H4) (6). The meta-substituted
monosulfonated triphenylphosphine P(C6H5)2(3-SO3-
NaC6H4) (4) has been used extensively as a supporting
ligand for water-soluble transition-metal complexes.18
Its para-isomer, 5, offers several advantages over 4,
including improved crystallinity of both the ligand and
its metal complexes, simplified spectroscopic character-
istics, and convenience of preparation and purification.
The analogous para-substituted monosulfonated triph-
enylarsine 6 is also easily prepared; its corresponding
meta-isomer has not been described previously. Both
5 and 6 have been known for some time; however, they
have not found use until very recently,19 since classical
preparations have yielded both ligands only as byprod-
ucts formed under forcing conditions.20
triphenylarsine in DME (eq 8). Negligible yields are
obtained via the reduction of either P(C6H5)3 or As-
(C6H5)3 in THF or diethyl ether. THF displays poor
stability in the presence of extremely reactive anions
such as phenylpotassium at room temperature,21 while
diethyl ether is too nonpolar to facilitate reduction of
the phosphine and arsine. Synthesis of 5 from P(C6H5)3
in analogy to eq 7 proceeds in only 28% yield. This poor
yield appears to result from reaction of the phosphide
anion with DME. Anhydrous 4-fluorobenzenesulfonic
acid was found to be a convenient source of protons for
selectively quenching phenylpotassium in the prepara-
tion of 6.
Recrystallization from water affords analytically pure
5 and 6 in 66% and 62% yields, respectively. Phosphine
5 forms a stable hydrate, while the arsine crystallizes
without associated water. This difference is reflected
(19) A modern synthesis of 5 has been developed recently using a
nucleophilic aromatic substitution similar to the method presented
here. See: (a) Herd, O.; Langhans, K. P.; Stelzer, O.; Weferling, N.;
Sheldrick, W. S. Angew. Chem., Int. Ed. Engl. 1993, 32, 1058. (b) Herd,
O.; Hessler, A.; Langhans, K.; Stelzer, O. J . Organomet. Chem. 1994,
475, 99. Instead of employing reducing metals, the authors generate
potassium diphenylphosphide in KOH/DMSO by deprotonation of
diphenylphosphine, an approach which has been used previously for
the alkylation of primary and secondary phosphines. See: (c) Tsvetkov,
E. N.; Bondarenko, N. A.; Malakhova, I. G.; Kabachnik, M. I. Synthesis
1986, 198 and references therein. On balance, the two methods appear
to be similar in terms of synthetic ease and reaction yield.
(20) (a) Schindlbauer, H. Monatsh. Chem. 1965, 96, 2051. (b)
Schindlbauer, H.; Lass, H. Monatsh. Chem. 1968, 99, 2460.
(21) See: Maercker, A. Angew. Chem., Int. Ed. Engl. 1987, 26, 972
and references therein.
Ligands 5 and 6 can be produced under mild condi-
tions and in good yields by reaction of potassium
4-fluorobenzenesulfonate with potassium diphenylphos-
phide or -arsenide, respectively. Reaction yields are
highly dependent on both the choice of solvent and the
(18) For reviews, see: (a) Kalck, P.; Monteil, F. Adv. Organomet.
Chem. 1992, 34, 219. (b) Herrmann, W. A.; Kohlpaintner, C. W.
Angew. Chem., Int. Ed. Engl. 1993, 32, 1524. (c) Li, C.-J . Chem. Rev.
1993, 93, 2023.

3712 Organometallics, Vol. 15, No. 17, 1996
Wallow et al.
perature even when stored under argon. Consequently, care
should be taken to prechill solvents used in the preparation
of these materials, and the exposure of the complexes to
ambient temperatures should be limited as much as possible.
They are, however, indefinitely stable when stored under argon
at -30 °C.
in their respective palladium complexes: lyophilization
yields arsine complex 1cc as a completely anhydrous
powder, whereas small amounts of water are very
difficult to remove even from lyophilized samples of
phosphine complexes 1bb,d d ,ee.
Liga n d Syn th esis. Meta-substituted phosphine 4 was
synthesized according to the literature procedure.25 Chlo-
rodiphenylphosphine was obtained commercially, stored in a
drybox, and used without further purification. Tripheny-
larsene was sublimed before use. Metallic potassium was
stripped of hydroxides and freshly cut in a drybox. Anhydrous
4-fluorobenzenesulfonic acid was obtained by stripping water
from the crystalline hydrate at 50 °C in vacuo, followed by
two Kugelrohr distillations. The anhydrous acid is an in-
tensely hygroscopic colorless liquid and must be handled with
complete exclusion of moisture. A 0.373 M stock solution was
prepared in toluene and stored at -20 °C in a Teflon stopcock
equipped Schlenk tube. Potassium 4-fluorobenzenesulfonate
was prepared by titrating an aqueous solution of the acid with
potassium bicarbonate, followed by recrystallization from
water. The resulting crystals were rinsed with cold water,
dried in vacuo at 80 °C for several hours, then ground into a
fine powder, and once again dried in vacuo at 80 °C overnight.
P r ep a r a tion of Or ga n ic-Solu ble P d Com p lexes 1a -z.
Gen er a l P r oced u r e fr om P r ecu r sor 2. THF solutions of
2 (92.0 mg, 0.0926 mmol), aryl iodide (0.185 mmol), and ligand
(0.370 mmol) were chilled to -30 °C and then combined in a
20 mL scintillation vial equipped with a stirbar. The reaction
was allowed to stir at room temperature until the deep violet
color faded to a bright yellow (generally 5-15 min), after which
the solvent was then removed with a rotary evaporator leaving
a yellow solid mass. This was dissolved in a minimum amount
of cold toluene (prechilled to -30 °C) and filtered onto a plug
of silica in a pipette with cold toluene as eluent. The product
eluted with the solvent front as a pale yellow band leaving
behind dibenzylideneacetone as an intense yellow band. The
solution was filtered through a 0.2 µm PTFE membrane and
then concentrated, layered with hexanes (2-4 volumes), and
chilled to -30 °C overnight. The resulting crystals were
collected via filtration and dried in vacuo or by lyophilization
from benzene.
Con clu sion
To summarize, the precursors Pd2(dba)3‚C6H6 (2) (dba
) t,t-dibenzylideneacetone) and (η3-allyl)PdCp (3) (Cp
) η5-cyclopentadienide) provide a convenient route into
ArPdL2I complexes. This methodology is tolerant of a
variety of functional groups, although it does not appear
to be a good method for the synthesis of the analogous
bromides or for complexes with sterically bulky or
extremely electron-poor phosphines. From these pre-
cursors, we have successfully synthesized a number of
organic and water soluble complexes for mechanistic
studies of the aryl-aryl exchange reaction and of Suzuki
coupling reactions in aqueous media. These investiga-
tions will be discussed in further disclosures.
Exp er im en ta l Section
Gen er a l Meth od s. Schlenk-line or drybox (Vacuum At-
mospheres Inc. HE-43-2 drybox equipped with a HE 493 Dry
Train; maintained under positive argon pressure) techniques
were used for all manipulations. 1H NMR spectra were
acquired at 300, 400, or 500 MHz using Bruker AM-series and
AMX-series spectrometers; proton-decoupled 13C, 19F, and 31P
spectra were obtained at corresponding frequencies. 1H and
13C chemical shifts are reported relative to tetramethylsilane,
31P chemical shifts are reported relative to 85% phosphoric
acid, and 19F chemical shifts are reported relative to fluoroben-
zene (δ ) -113.1). THF, DME, diethyl ether, hexanes, and
toluene were purified by distillation from sodium/benzophe-
none and used immediately. DMF was dried over 4 Å
molecular sieves, filtered, and vacuum distilled prior to use.
Water and alcohols were deoxygenated by prolonged sparging
with an argon stream. Aryl halides were obtained from
Aldrich and sublimed or distilled prior to use. Organic soluble
phosphines except phenyldi-o-tolylphosphine were used as
received from Strem Chemicals. Phenyldi-o-tolylphosphine
was prepared from a literature procedure.22 Mass spectra were
performed by the U.C. Berkeley Mass Spectrometry Labora-
tory. Analytical data were obtained by the elemental analysis
facilities at the University of California at Berkeley and the
University of Massachusetts at Amherst.
P a lla d iu m Com p lex Syn th esis. Complexes 213a and 323
were synthesized by standard methods. Caution! Complex 3
is a modestly air-stable, highly volatile organometallic. While
we are unaware of documented health risks associated with 3
in particular, volatile transition metal complexes, specifically
those of the nickel triad, can be quite toxic. Complex 3 has a
painful, piercingly noxious odor and should be handled ac-
cordingly. 1H, 19F, and 31P NMR characterization of complexes
1a -ee was quite straightforward. 13C NMR spectra were
complicated by multiple couplings and 13C-31P virtual cou-
pling.24 In combination with the limited solubility of complexes
1a -ee, these effects hampered the detection of weak, multiply
split, or overlapping resonances. As a result, complete 13C
NMR spectral assignments were not possible in many cases.
Partial tabulations are included, where appropriate. Com-
plexes 1a -ee are not particularly robust and decompose
thermally over the course of hours (for complexes made from
electron-donating aryl iodides) to several weeks (for complexes
made from electron-withdrawing aryl iodides) at room tem-
Gen er a l P r oced u r e fr om P r ecu r sor 3. THF solutions
(1 mL) of 3 (39.4 mg, 0.185 mmol), aryl iodide (0.185 mmol),
and ligand (0.370 mmol) were chilled to -30 °C and then
combined in a 20 mL scintillation vial equipped with a stirbar.
The reaction was allowed to stir at room temperature until
the deep orange-red color faded to a pale yellow (generally
5-15 min), after which the solution was filtered through a 0.2
µm PTFE membrane, concentrated, layered with hexanes, and
chilled to -30 °C overnight. The resulting crystalline mass
was then collected via filtration and dried in vacuo or by
lyophilization from benzene.
6H5)3]2I (1a ).3 Syn th esized
(4-Meth oxyp h en yl)P d [P (C
fr om 3. The above general procedure was followed by utilizing
19.8 mg (0.0925 mmol) of 3, 21.7 mg (0.0925 mmol) of 4-iodo-
anisole, 48.5 mg (0.185 mmol) of triphenylphosphine, and dry,
degassed CH2Cl2 as solvent. A 72.0 mg amount of a pale
(24) 2J P-P coupling in square-planar Pd(II) diphosphine complexes
produces AXX′ or A[X]2 spin systems observable in {1H} 13C NMR
2
spectra. In the limit where J P-P is large, 13C resonances resolve into
apparent triplets. For discussions, see: (a) Redfield, D. A.; Cary, L.
W.; Nelson, J . H. Inorg. Chem. 1975, 14, 1975. (b) Pregosin, P. S.;
Kunz, R. Helv. Chim. Acta 1975, 58, 423. (c) Verstuyft, A. W.; Nelson,
J . H.; Cary, L. W. Inorg. Chem. 1976, 15, 732. (d) Verstuyft, A. W.;
Redfield, D. A.; Cary, L. W.; Nelson, J . H. Inorg. Chem. 1976, 15, 1128.
(e) Pregosin, P. S., Kunz, R. W. 31P and 13C NMR of Transition Metal
Phosphine Complexes; Springer: Berlin, 1979; pp 65-74.
(25) (a) Ahrland, S.; Chatt, J .; Davies, N. R.; Williams, A. A. J . Chem.
Soc. 1958, 90, 276. Very recently, notable improvements in the
synthesis of m-sulfonated triarylphosphines have been realized by
using H2SO4/SO3/B(OH)3 as the sulfonating medium. (b) Herrmann,
W. A.; Albanese, G. P.; Manetsberger, R. B.; Lappe, P.; Bahrmann, H.
Angew. Chem., Int. Ed. Engl. 1995, 34, 811.
(22) Bennett, M. A.; Longstaff, P. A. J . Am. Chem. Soc. 1969, 91,
6266.
(23) Tatsuno, Y.; Yoshida, T.; Otsuka, S. Inorg. Synth. 1990, 28, 342.

ArPdL2I Complexes
Organometallics, Vol. 15, No. 17, 1996 3713
greenish-yellow powder, 1a , was recovered (0.0832 mmol,
90%): 1H NMR (CDCl3) δ 3.48 (s, 3H), 5.92 (d, J ) 8.6Hz, 2H),
6.40 (m, 2H), 7.24 (apparent t, J app ) 7.1 Hz, 12H), 7.29
(apparent t, J app ) 7.2 Hz, 6H), 7.50 (m, 12H); 13C NMR
(CDCl3) δ 55.4, 114.5, 127.7 (apparent t, J app ) 5.2 Hz), 129.7,
23.5 Hz), 134.8 (apparent t, J app ) 6.2 Hz), 135.7 (apparent t,
J app ) 4.9 Hz), additional resonances not resolved; 19F NMR
(CDCl3) δ -61.7; 31P NMR (CDCl3) δ 23.7. Anal. Calcd for
C
43H34F3IP2Pd: C, 57.20; H, 3.80. Found: C, 57.09; H, 3.94.
(2-Met h ylp h en yl)P d [P (C6H 5)3]2I (1f).28 Syn t h esized
132.3 (apparent t, J app ) 23.0 Hz), 134.9 (apparent t, J app
)
fr om 3. The above general procedure was followed using 39.4
mg (0.185 mmol) of 3, 40.4 mg (0.185 mmol) of 2-iodotoluene,
and 97.0 mg (0.370 mmol) of triphenylphosphine to yield 0.149
g of 1f as a pale greenish-yellow powder (0.175 mmol, 95%):
1H NMR (CDCl3) δ 1.82 (s, 3H), 6.08 (d, J ) 7.0 Hz, 1H), 6.26
(apparent t, J app ) 7.2 Hz, 1H), 6.39 (apparent t, J app ) 7.2
Hz, 1H), 6.86 (m, 1H), 7.22 (apparent t, J app ) 7.5 Hz, 12H),
7.31 (apparent t, J app ) 7.4 Hz, 6H), 7.46 (m, 12H); 13C NMR
(CDCl3) δ 15.3, 122.9, 124.1, 127.7 (apparent t, J app ) 5.0 Hz),
129.7, 130.4, 132.1 (apparent t, J app ) 22.8 Hz), 134.8, 134.9
(apparent t, J app ) 6.1 Hz), 141.2, 159.8; 31P NMR (CDCl3) δ
6.2 Hz), 135.7, additional resonances not resolved; 31P NMR
(CDCl3) δ 22.9. Anal. Calcd for C43H37IOP2Pd: C, 59.71; H,
4.31. Found: C, 59.84; H, 4.24.
(4-Meth ylp h en yl)P d [P (C6H5)3]2I (1b).26 Syn th esized
fr om 3. The above general procedure was followed using 39.4
mg (0.185 mmol) of 3, 40.4 mg (0.185 mmol) of 4-iodotoluene,
97.0 mg (0.370 mmol) of triphenylphosphine, and dry, degassed
CH2Cl2 as solvent. This yielded 137.2 mg of a pale greenish-
yellow powder, 1b (0.162 mmol, 87%): 1H NMR (CDCl3) δ 1.91
(s, 3H), 6.07 (d, J ) 7.6 Hz, 2H), 6.40 (dt, J ) 8.0 Hz, J ) 2.2
Hz, 2H), 7.22 (m, 12H), 7.30 (t, J ) 7.6 Hz, 6H), 7.49 (m, 12H);
13C NMR (CDCl3) δ 20.1, 127.7 (apparent t, J app ) 5.1 Hz),
128.9 129.6, 131.0, 132.3 (apparent t, J app ) 22.9 Hz) 134.9
(apparent t, J app ) 6.3 Hz), 135.5 (br m) additional resonances
not resolved; 31P NMR (CDCl3) δ 22.6.
22.7. Anal. Calcd for
Found: C, 60.99; H, 4.33.
C43H37IP2Pd: C, 60.83; H, 4.39.
(2-Meth oxyp h en yl)P d [P (C6H5)3]2I (1g). Syn th esized
fr om 3. The above general procedure was followed using 39.4
mg (0.185 mmol) of 3, 43.3 mg (0.185 mmol) of 2-iodoanisole,
and 97.0 mg (0.370 mmol) of triphenylphosphine yielding 0.159
g of 1g, a pale greenish-yellow powder (0.184 mmol, 99%): 1H
NMR (CDCl3) δ 3.05 (s, 3H), 5.40 (dd, J ) 8.1 Hz, J ) 1.3 Hz,
1H), 6.17 (apparent t, J app ) 7.2 Hz, 1H), 6.37 (apparent t,
J app ) 7.3 Hz, 1H), 6.86 (m, 1H), 7.21 (m, 12H), 7.28 (apparent
t, J app ) 7.3 Hz, 6H), 7.52 (m, 12 H); 13C NMR (CDCl3) δ 53.6,
109.2, 120.0, 124.0, 127.5 (apparent t, J app ) 5 Hz), 129.5, 132.6
(4-F lu or op h en yl)P d [P (C6H 5)3]2I (1c).27 Syn t h esized
fr om 3. The above general procedure was followed using 39.4
mg (0.185 mmol) of 3, 41.1 mg (0.185 mmol) of 4-fluoroiodo-
benzene, and 97.0 mg (0.370 mmol) of triphenylphosphine to
yield 150.1 mg of 1c as greenish-white flakes (0.176 mmol,
95%): 1H NMR (CDCl3) δ 6.02 (m, 2H), 6.48 (m, 2H), 7.25 (t,
J ) 7.3 Hz, 12H), 7.33 (t, J ) 7.3 Hz, 6H), 7.51 (m, 12H); 13C
NMR (CDCl3) δ 114.5 (d, J C-F ) 18.9 Hz), 127.8 (apparent t,
(apparent t, J app ) 22.8 Hz), 134.2, 134.8 (apparent t, J app
)
6.4 Hz), 146.0, 159.0; 31P NMR (CDCl3) δ 23.1. Anal. Calcd
for C43H37IOP2Pd: C, 59.71; H, 4.31. Found: C, 59.47; H, 4.24.
(P h en yl)P d [P (4-m eth oxyp h en yl)3]2I (1h ). Syn th esized
fr om 3. The above general procedure was followed using 39.4
mg (0.185 mmol) of 3, 37.8 mg (0.185 mmol) of iodobenzene,
and 130.2 mg (0.370 mmol) of tris(4-methoxyphenyl)phosphine
to yield 0.169 g of 1h , a white powdery solid (0.166 mmol,
90%): 1H NMR (CDCl3) δ 3.77 (s, 18H), 6.24 (apparent t, J app
) 7.4 Hz, 2H), 6.36 (t, J ) 7.2 Hz, 1H), 6.56 (m, 2H), 6.74 (d,
J ) 8.6 Hz, 12H), 7.37 (m, 12H); 13C NMR (CDCl3) δ 55.2, 113.4
J app ) 5.1 Hz), 129.8, 132.0 (apparent t, J app ) 23.4 Hz), 134.9
1
(apparent t, J app ) 6.2 Hz), 135.8 (m), 151.6, 160.2 (d, J C-F
)
239.5 Hz); 19F NMR (CDCl3) δ -125.1; 31P NMR (CDCl3) δ 22.9.
(4-Nitr oph en yl)P d[P (C6H5)3]2I (1d).9a Syn th esized fr om
2. A solution of 4-iodonitrobenzene (0.052 g, 0.204 mmol) and
triphenylphosphine (0.106 g, 0.408 mmol) in 3 mL of THF was
added to a solution of Pd2(dba)3‚C6H6 (2) (0.100 g, 0.101 mmol)
in 2 mL of THF. The reaction was complete within 5 min;
the solution was filtered through a 0.2 µm PTFE membrane
which was rinsed with additional THF until any precipitated
product had redissolved. The filtrate was concentrated, two
volumes of hexanes were added, and the flask was chilled for
several hours (-30 °C) to yield 0.170 g of complex 1d as a
crystalline mono-THF solvate (0.179 mmol, 89%).
(apparent t, J app ) 5.7 Hz), 121.6, 124.1 (apparent t, J app
)
25.2 Hz), 127.3, 136.2 (apparent t, J app ) 6.9 Hz), 160.6, 161.2,
one additional resonance not resolved; 31P NMR (CDCl3) δ 19.5.
Anal. Calcd for C48H47IO6P2Pd: C, 56.79; H, 4.67. Found: C,
56.89; H, 4.93.
Syn th esized fr om 3. A solution of 4-iodonitrobenzene
(0.052 g, 0.204 mmol) and triphenylphosphine (0.106 g, 0.408
mmol) in 3 mL of THF was added to a solution of (η3-allyl)-
PdCp (3) (0.043 g, 0.202 mmol) in 2 mL of THF. The reaction
was stirred for 5 min and then filtered, concentrated, layered
with hexanes, and chilled to -30 °C. Collection of the
crystalline deposit yielded 0.181 g of complex 1d as the THF
solvate (0.191 mmol, 94%): 1H NMR (CDCl3) δ 6.86 (d, J )
8.7 Hz, 1H), 7.03 (d, J ) 8.7 Hz, 1H), 7.25 (m, 6H), 7.35 (m,
3H), 7.55 (m, 6H); 13C NMR (CDCl3) δ 120.8, 127.9 (apparent
t, J app ) 5.1 Hz), 130.2, 131.3 (apparent t, J app ) 23.7 Hz),
134.8 (apparent t, J app ) 6.2 Hz), 135.8, 143.7, 176.9, additional
resonances not resolved; 31P NMR (CDCl3) δ 23.2.
(4-Meth ylp h en yl)P d [P (4-m eth oxyp h en yl)3]2I (1i). Syn -
th esized fr om 3. The above general procedure was followed
using 39.4 mg (0.185 mmol) of 3, 40.4 mg (0.185 mmol) of
4-iodotoluene, and 130.2 mg (0.370 mmol) of tris(4-methox-
yphenyl)phosphine to yield 0.184 g of 1i as a white powdery
solid (0.179 mmol, 97%): 1H NMR (CDCl3) δ 1.96 (s, 3H), 3.79
(s, 18 H), 6.12 (d, J ) 7.5 Hz, 2H), 6.40 (m, 2H), 6.76 (d, J )
8.8 Hz, 12H), 7.40 (m, 12H); 13C NMR (CDCl3) δ 20.2, 55.2,
113.3 (apparent t, J app ) 5.4 Hz), 124.1 (apparent t, J app
)
25.5), 128.4, 130.5, 135.6, 136.3 (apparent t, J app ) 6.9 hz),
155.3, 160.5; 31P NMR (CDCl3) δ 19.1. Anal. Calcd for
C
49H49IO6P2Pd: C, 57.19; H, 4.76. Found: C, 56.94; H, 4.90.
(4-(Tr iflu or om eth yl)ph en yl)P d[P (C6H5)3]2I (1e).9c,d Syn -
th esized fr om 2. The above procedure for 1d employing
4-iodobenzotrifluoride (0.056 g, 0.204 mmol) triphenylphos-
phine (0.106 g, 0.408 mmol), and Pd2(dba)3‚C6H6 (2) (0.100 g,
0.101 mmol) yielded 0.169 g of complex 1e as a mono-THF
solvate (0.173 mmol, 86%).
(4-F lu or op h en yl)P d [P (4-m eth oxyp h en yl)3]2I (1j). Syn -
th esized fr om 3. The above general procedure was followed
using 39.4 mg (0.185 mmol) of 3, 41.1 mg (0.185 mmol) of
p-fluoroiodobenzene, and 130.2 mg (0.370 mmol) of tris(4-
methoxyphenyl)phosphine to yield 0.188 g of 1j as a white
powdery solid (0.182 mmol, 98%): 1H NMR (CDCl3) δ 3.78 (s,
18H), 6.05 (app t, J ) 9.2 Hz, 2H), 6.45 (m, 2H), 6.76 (d, J )
8.8 Hz, 12H), 7.39 (m, 12H); 13C NMR (CDCl3) δ 55.2, 113.4
(apparent t, J app ) 5.5 Hz), 113.9 (d, J C-F ) 18.9 Hz), 123.8
(apparent t, J app ) 25.6 Hz), 135.9 (apparent dt, J app ) 5.5
Hz, J app ) 5.1 Hz), 136.2 (apparent t, J app ) 6.9 Hz) 136.2
(apparent t, J app ) 6.9 Hz), 153.9, 160.0 (d, 1J C-F ) 237.3 Hz),
160.7; 19F NMR (CDCl3) δ -125.5; 31P NMR (CDCl3) δ 19.4 (d,
Syn th esized fr om 3. The above procedure for 1d yielded
0.175 g of complex 1e as a mono-THF solvate (0.180 mmol,
89%): 1H NMR (CDCl3) δ 6.39 (d, J ) 8.0 Hz, 1H), 6.71 (d, J
) 8.0 Hz, 1H), 7.24 (m, 6H), 7.31 (m, 3H), 7.51 (m, 6H); 13C
1
NMR (CDCl3) δ 123.3 (m), 124.9 (q, J C-F ) 265.5 Hz), 127.9
(apparent t, J app ) 5.1 Hz), 130.0, 131.6 (apparent t, J app
)
(26) Amatore, C.; J utand, A.; Khalil, F.; Nielsen, M. F. J . Am. Chem.
Soc. 1992, 114, 7076.
(27) Sekiya, A.; Ishikawa, N. J . Organomet. Chem. 1976, 118, 349.
(28) Nakamura, Y.; Maruya, K.; Mizoroki, T. Nippon Kagaku Kaishi
1978, 1486.

3714 Organometallics, Vol. 15, No. 17, 1996
Wallow et al.
J P-F ) 3.2 Hz). Anal. Calcd for C48H46FIO6P2Pd: C, 55.80;
H, 4.49. Found: C, 55.78; H, 4.49.
(P h en yl)P d [P (4-flu or op h en yl)3]2I (1p ). Syn th esized
fr om 3. The above general procedure was applied using 39.4
mg (0.185 mmol) of 3, 37.8 mg (0.185 mmol) of iodobenzene,
and 117.0 mg (0.370 mmol) of tri-p-fluorophenylphosphine to
yield 1p as bright yellow crystals. These were then freeze-
dried from benzene in order to remove solvent of crystallization
(0.158 g, 0.168 mmol, 91%): 1H NMR (CDCl3) δ 6.32 (apparent
t, J app ) 7.3 Hz, 2H), 6.45 (t, J ) 7.2 Hz, 1H), 6.53 (m, 2H),
6.95 (apparent t, J app ) 8.8 Hz, 12 H), 7.41 (m, 12H); 13C NMR
(CDCl3) δ 115.4 (apparent dt, J app ) 21.2 Hz, J app ) 5.5 Hz),
122.5, 127.3 (apparent td, J app ) 24.4 Hz, J app ) 3.3 Hz), 128.3,
(4-(Tr iflu or om e t h yl)p h e n yl)P d [P (4-m e t h oxyp h e n -
yl)3]2I (1k ). Syn th esized fr om 3. The above general pro-
cedure was followed by utilizing 19.8 mg (0.0925 mmol) of 3,
25.2 mg (0.0925 mmol) of 4-iodobenzotrifluoride, and 65.1 mg
(0.185 mmol) of tris(4-methoxyphenyl)phosphine. This yielded
0.094 mg (0.087 mmol, 94%) of 1k as a pale yellow powder:
1H NMR (CDCl3) δ 3.77 (s, 18H), 6.44 (d, J ) 8.0, 2H), 6.69 (d,
J ) 8.0 Hz, 2H), 6.75 (d, J ) 8.8 Hz, 12H), 7.39 (m, 12H); 13
C
NMR (CDCl3) δ 55.1, 122.8 (br), 123.4 (apparent t, J app ) 25.7
Hz), 135.7 (br), 136.1 (apparent t, J app ) 7.0 Hz), 160.8,
additional resonances not resolved; 19F NMR (CDCl3) δ -61.8;
31P NMR (CDCl3) δ 19.5. Anal. Calcd for C49H46F3IO6P2Pd:
C, 54.34; H, 4.28. Found: C, 54.20; H, 4.33.
135.8 (apparent t, J app ) 4.8 Hz), 136.7 (apparent dt, J app
)
1
8.0 Hz, J app ) 7.1 Hz), 159.3, 163.8 (d, J C-F ) 250.6 Hz); 19F
NMR (CDCl3) δ -109.3; 31P NMR (CDCl3) δ 20.9. Anal. Calcd
for C42H29F6IP2Pd: C, 54.43; H, 3.67. Found: C, 54.28; H, 3.64.
(4-Meth oxyp h en yl)P d [P (4-flu or op h en yl)3]2I (1q). Syn -
th esized fr om 3. The above general procedure was applied
using 78.8 mg (0.370 mmol) of 3, 86.6 mg (0.370 mmol) of
iodoanisole, and 234.0 mg (0.740 mmol) of tri-p-fluorophe-
nylphosphine to yield 1q as pale greenish-yellow feathery
crystals (0.320 g, 0.329 mmol, 89%): 1H NMR (CDCl3) δ 3.52
(s, 3H), 6.02 (d, J ) 8.5 Hz, 2H), 6.33 (d, J ) 8.5 Hz, 2H), 6.96
(apparent t, J app ) 8.5 Hz, 12H), 7.42 (m, 12H); 13C NMR
(CDCl3) δ 55.4, 114.8, 115.4 (apparent dt, J app ) 21.4 Hz, J app
) 5.5 Hz), 125.8, 127.4 (apparent t, J app ) 24.1 Hz), 135.5 (br
m), 136.8 (apparent dt, J app ) 7.9 Hz, J app ) 7.4 Hz), 156.6,
163.8 (d, 1J C-F ) 252.5 Hz), additional resonances not resolved;
19F NMR (CDCl3) δ -109.3; 31P NMR (CDCl3) δ 20.8. Anal.
Calcd for C43H31F6IOP2Pd: C, 53.97; H, 3.26. Found: C, 53.70;
H, 3.12.
(P h en yl)P d [P (4-m eth ylp h en yl)3]2I (1l). Syn th esized
fr om 3. The above general procedure was applied using 39.4
mg (0.185 mmol) of 3, 37.8 mg (0.185 mmol) of iodobenzene,
and 112.4 mg (0.370 mmol) of tri-p-tolylphosphine to yield 1l
as a yellow crystalline mass. Residual solvent was removed
via lyophilization from benzene (0.145 g, 0.158 mmol, 85%):
1H NMR (CDCl3) δ 2.30 (s, 18H), 6.17 (app t, J ) 7.5 Hz, 2H),
6.32 (t, J ) 7.2 Hz, 1H), 6.54 (m, 2H), 7.01 (d, J ) 7.7 Hz,
12H), 7.35 (m, 12H); 13C NMR (CDCl3) δ 21.4, 121.3, 127.5,
128.4 (apparent t, J app ) 5.2 Hz), 129.3 (apparent t, J app
)
23.7 Hz), 134.8 (apparent t, J app ) 6.3 Hz), 136.1 (br), 139.5,
159.7; 31P NMR (CDCl3) δ 21.1. Anal. Calcd for C48H47IP2Pd:
C, 62.72; H, 5.15. Found: C, 62.92; H, 5.21.
(4-Meth oxyph en yl)P d[P (4-m eth ylph en yl)3]2I (1m ). Syn -
th esized fr om 3. The above general procedure was applied
using 39.4 mg (0.185 mmol) of 3, 43.3 mg (0.185 mmol) of
iodoanisole, and 112.4 mg (0.370 mmol) of tri-p-tolylphosphine
to yield 1m as yellow needlelike crystals. Residual solvent
was removed by freeze-drying the product from benzene
(0.153g, 0.161 mmol, 87%): 1H NMR (CDCl3) δ 2.30 (s, 18H),
3.47 (s, 3H), 5.89 (d, J ) 8.6 Hz, 2H), 6.35 (m, 2H), 7.02 (d, J
) 7.7 Hz, 12H), 7.37 (m, 12H); 13C NMR (CDCl3) δ 21.4, 55.3,
114.1, 128.4 (apparent t, J app ) 5.1 Hz), 129.3 (apparent t, J app
) 23.8), 134.6, 134.8 (apparent t, J app ) 6.2 Hz), 135.7, 136.6,
139.5; 31P NMR (CDCl3) δ 21.0. Anal. Calcd for C49H49IOP2-
Pd: C, 62.01; H, 5.20. Found: C, 61.70; H, 5.20.
(4-Meth ylp h en yl)P d [P (4-flu or op h en yl)3]2I (1r ). Syn -
th esized fr om 3. The above general procedure was applied
using 19.8 mg (0.0925 mmol) of 3, 20.2 mg (0.0925 mmol) of
iodotoluene, and 58.5 mg (0.185 mmol) of tri-p-fluorophe-
nylphosphine to yield 1r as pale greenish-yellow feathery
crystals (69.1 mg, 0.0722 mmol, 78%): 1H NMR (CDCl3) δ 1.98
(s, 3H), 6.19 (d, J ) 6.0 Hz, 2H), 6.35 (d, J ) 6.1 Hz, 2H), 6.95
(m, 12H), 7.41 (m, 12H); 13C NMR (CDCl3) δ 20.1, 115.3
(apparent dt, J app ) 21.3 Hz, J app ) 5.7 Hz), 127.3 (apparent
td, J app ) 24.2 Hz, J app ) 3.3 Hz), 129.3, 132.0, 135.3 (apparent
t, J app ) 5.2 Hz), 136.8 (apparent dt, J app ) 7.7 Hz, J app ) 7.4
1
Hz), 153.5, 163.9 (d, J C-F ) 252.3 Hz); 19F NMR (CDCl3) δ
-109.5; 31P NMR (CDCl3) δ 20.6. Anal. Calcd for C43H31
F6IOP2Pd: C, 53.97; H, 3.27. Found: C, 53.93; H, 3.62.
-
(4-F lu or op h en yl)P d [P (4-m eth ylp h en yl)3]2I (1n ). Syn -
th esized fr om 3. The above general procedure was applied
using 39.4 mg (0.185 mmol) of 3, 41.1 mg (0.185 mmol) of
4-fluoroiodobenzene, and 112.4 mg (0.370 mmol) of tri-p-
tolylphosphine to yield 1n as a yellow crystalline mass.
Residual solvent was removed by freeze-drying the product
from benzene (0.162 g, 0.173 mmol, 93%): 1H NMR (CDCl3) δ
2.30, (s, 12H), 5.98 (d, J ) 7.4 Hz, 2H), 6.43 (m, 2H), 7.02 (d,
J ) 8.0 Hz, 12H), 7.37 (m, 12H); 13C NMR (CDCl3) δ 21.3, 114.0
(d, J C-F ) 18.9 Hz), 128.5 (apparent t, J app ) 5.3 Hz), 129.1
(apparent t, J app ) 24.2 Hz), 134.8 (apparent t, J app ) 6.5 Hz),
(4-(Tr iflu or om et h yl)p h en yl)P d [P (4-flu or op h en yl)3]2I
(1s). Syn th esized fr om 3. The above general procedure was
applied using 19.8 mg (0.0925 mmol) of 3, 25.2 mg (0.0925
mmol) of 4-iodobenzotrifluoride, and 58.5 mg (0.185 mmol) of
tri-p-fluorophenylphosphine to yield 1s as pale greenish-yellow
feathery crystals (84.3 mg, 0.0834 mmol, 90%): 1H NMR
(CDCl3) δ 6.55 (d, J ) 7.9 Hz, 2H), 6.68 (d, J ) 7.9 Hz, 2H),
6.97 (t, J ) 8.6 Hz, 12H), 7.58 (m, 12H); 13C NMR (CDCl3) δ
115.6 (apparent dt, J app ) 21.3 Hz, J app ) 5.7 Hz), 123.7, 126.5
(apparent td, J app ) 24.8 Hz, J app ) 3.6 Hz), 135.6 (apparent
t, J app ) 5.1 Hz), 136.7 (apparent dt, J app ) 7.6 Hz, J app ) 7.3
Hz), 164.0 (d, 1J C-F ) 253.6 Hz), additional resonances overlap;
19F NMR (CDCl3) δ -108.6, -62.3; 31P NMR (CDCl3) δ 20.9.
Anal. Calcd for C43H28F9IP2Pd: C, 51.09; H, 2.80. Found: C,
50.99; H, 2.99.
135.8 (m), 139.7, 152.6, additional resonances not resolved; 19
NMR (CDCl3) δ -125.6; 31P NMR (CDCl3) δ 21.1 (d, J P-F
F
)
3.8 Hz). Anal. Calcd for C48H46FIP2Pd: C, 61.52; H, 4.95.
Found: C, 61.20; H, 4.98.
(4-(T r iflu o r o m e t h y l)p h e n y l)P d [P (4-m e t h y lp h e n -
yl)3]2I (1o). Syn th esized fr om 3. The above general pro-
cedure was applied using 19.8 mg (0.0925 mmol) of 3, 25.2
mg (0.0925 mmol) of 4-iodobenzotrifluoride, and 56.2 mg (0.185
mmol) of tri-p-tolylphosphine to yield 1o as a pale yellow,
feathery precipitate (48.6 mg, 0.0492 mmol, 53%): 1H NMR
(CDCl3) δ 2.29 (s, 18H), 6.32 (d, J ) 8.0 Hz, 2H), 6.64 (d, J )
8.0 Hz, 2H), 7.02 (d, J ) 7.6 Hz, 12H), 7.38 (m, 12H); 13C NMR
(CDCl3) δ 122.9 (q, J C-F ) 3.9 Hz), 123.6 (br), 128.6 (apparent
t, J app ) 5.3 Hz), 128.7 (apparent t, J app ) 24.2 Hz), 134.7
(apparent t, J app ) 6.5 Hz), 135.7 (apparent t, J app ) 4.9 Hz),
140.0, additional resonances not resolved; 19F NMR (CDCl3) δ
-62.0; 31P NMR (CDCl3) δ 21.3. Anal. Calcd for C49H46F3IP2-
Pd: C, 59.62; H, 4.70. Found: C, 59.35; H, 4.87.
(P h en yl)P d [P (4-(tr iflu or om eth yl)p h en yl)3]2I (1t). Syn -
th esized fr om 2. The above general procedure was followed
utilizing 92.0 mg (0.0925 mmol) of 2, 37.8 mg (0.185 mmol) of
iodobenzene, and 172.4 mg (0.370 mmol) of tris(4-(trifluorom-
ethyl)phenyl)phosphine to yield 80.3 mg of 1t as pale yellow
feathery crystals (0.0646 mmol, 35%): 1H NMR (CDCl3) δ 6.28
(apparent t, J app ) 7.5 Hz, 2H), 6.43 (d, J ) 7.3 Hz, 1H), 6.47
1
(m, 2H), 7.58 (m, 24H); 13C NMR 9CDCl3) δ 123.5 (q, J C-F
)
271.2 Hz), 125.1 (m), 129.1, 132.6 (q, J C-F ) 32.6 Hz), 134.6
(apparent t, J app ) 22.9 Hz), 134.9 (apparent t, J app ) 6.6 Hz);
135.4 (apparent t, J app ) 5.1 Hz); 157.8, additional resonances
not resolved; 19F NMR (CDCl3) δ -63.2; 31P NMR (CDCl3) δ

ArPdL2I Complexes
Organometallics, Vol. 15, No. 17, 1996 3715
23.2. Anal. Calcd for C48H29F18IP2Pd: C, 46.38; H, 2.36.
Found: C, 46.05; H, 2.43.
127.8 (apparent t, J app ) 5.0 Hz), 128.5, 129.5, 131.6 (apparent
t, J app ) 21.3 Hz), 133.8 (apparent t, J app ) 5.7 Hz), 135.5
(apparent t, J app ) 4.9 Hz), 141.2, 149.9; 31P NMR (CDCl3) δ
17.0. Anal. Calcd for
Found: C, 56.02; H, 5.10.
(4-Met h ylp h en yl)P d (1,3-b is(d ip h en ylp h osp h in o)p r o-
p a n e)I (1z). Syn th esized fr om 3. The above general proce-
dure was applied using 39.4 mg (0.185 mmol) of 3, 40.4 mg
(0.185 mmol) of 4-iodotoluene, and 78.8 mg (0.185 mmol) of
1,3-bis(diphenylphosphino)propane to yield 1z as pale green-
yellow crystals which turned pinkish upon exposure to ambient
temperature. The crystals were then freeze-dried from ben-
zene in order to remove solvent of crystallization (0.125 g,
0.170 mmol, 92%): 1H NMR (CDCl3) δ 1.85 (m, 2H), 1.99 (s,
(4-Me t h oxyp h e n yl)P d [P (4-(t r iflu or om e t h yl)p h e n -
yl)3]2I (1u ). Syn th esized fr om 2. The above general pro-
cedure was followed utilizing 92.0 mg (0.0925 mmol) of 2, 43.3
mg (0.185 mmol) of 4-iodoanisole, and 172.4 mg (0.370 mmol)
of tris(4-(trifluoromethyl)phenyl)phosphine to yield 0.172 g of
1u as pale yellow feathery crystals (0.135 mmol, 73%).
Syn th esized fr om 3. The above general procedure was
applied using 19.8 mg (0.0925 mmol) of 3, 21.7 mg (0.0925
mmol) of 4-iodoanisole, and 86.3 mg (0.185 mmol) of tris(4-
(trifluoromethyl)phenyl)phosphine to yield 1u as pale yellow
feathery crystals (91.2 mg, 77%): 1H NMR (CDCl3) δ 3.44 (s,
C35H37IP2Pd: C, 55.83; H, 4.95.
3H), 5.97 (d, J ) 8.4 Hz, 2h), 6.27 (m, 2H), 7.60 (m, 24 H); 13
C
NMR (CDCl3) δ 54.8, 115.4, 123.5 (q, 1J C-F ) 271.2 Hz), 125.1
3H), 2.39 (m, 2H), 2.51 (m, 2H), 6.39 (m, 2H), 6.74 (td, J t
)
?
8.0 Hz, J d ) 2.6 Hz, 2H), 7.12 (td, J t ) 7.8 Hz, J d ) 2.4 Hz,
4H), 7.28 (m, 6H), 7.41 (m, 6H), 7.81 (m, 4H); 13C NMR (CDCl3)
δ 19.0, 20.4, 27.1 (broad), 28.6 (dd, J ) 24.6 Hz, 7.4 Hz), 128.0
(d, J ) 10.6 Hz), 128.2, 128.4 (d, J ) 9.6 Hz), 130.1, 130.5,
130.9, 132.8, 133.1 (d, J ) 10.7 Hz), 133.7 (d, J ) 11.0 Hz),
136.6, additional resonances not resolved; 31P NMR (CDCl3) δ
-10.6 (d, J PP ) 53.2 Hz), 10.9 (d, J PP ) 53.2 Hz). Anal. Calcd
for C43H33IP2Pd: C, 55.42; H, 4.51. Found: C, 55.17; H, 4.54.
P r ep a r a tion of Wa ter -Solu ble Com p lexes 1a a -ee. ((3-
Met h oxyca r b on yl)p h en yl)P d [P (C6H5)2(3-SO3Na C6H4)]2I
(1a a ). A solution of methyl 3-iodobenzoate (0.250 g, 0.955
mmol) and monosulfonated triphenylphosphine (4) (0.695 g,
1.91 mmol) dissolved in 7.5 mL of DMF was added to a slurry
of Pd2(dba)3‚C6H6 (2) (0.470 g, 0.48 mmol) in 2.5 mL of DMF.
All 2 dissolved over the course of 1 h to yield a homogeneous
yellow solution. The solution was filtered through a 0.2 µm
PTFE membrane to remove traces of metallic Pd. Complex
1a a was precipitated as a slush by addition of several volumes
of ether. Repeated ethereal washes yielded a free-flowing
powder, which was collected by filtration and dried in vacuo
to give 0.999 g of complex 1a a (0.910 mmol, 94%) suitable for
routine use. Similar reactions using 4 in the presence of
precursor 3 failed to yield identifiable products. Highly
purified material was obtained by dissolving 1a a in warm (40
°C) methanol, filtering, concentrating the solution in vacuo,
and chilling (-20 °C). The resulting powder was free of
(m), 132.6 (q, J C-F ) 32.8 Hz), 134.8 (apparent t, J app ) 22.4
Hz), 135.0 (apparent t, J app ) 6.6 Hz), 157.0; 19F NMR (CDCl3)
δ -63.2; 31P NMR (CDCl3) δ 23.0. Anal. Calcd for C49H31F18
-
IOP2Pd: C, 46.23; H, 2.46. Found: C, 45.97; H, 2.58.
(4-Me t h y lp h e n y l)P d [P (4-(t r i flu o r o m e t h y l)p h e n -
yl)3]2I (1v). Syn th esized fr om 2. The above general pro-
cedure was followed by utilizing 92.0 mg (0.0925 mmol) of 2,
40.4 mg (0.185 mmol) of 4-iodotoluene, and 172.4 mg (0.370
mmol) of tris(4-(trifluoromethyl)phenyl)phosphine to yield
0.131 g of 1v as a white, fluffy precipitate (0.104 mmol, 56%):
1H NMR (CDCl3) δ 1.90 (s, 3H), 6.11 (d, J ) 7.5 Hz, 2H), 6.28
(m, 2H), 7.54 (d, J ) 8.0 Hz, 12H), 7.61 (m, 12H); 13C NMR
1
(CDCl3) δ 19.6, 123.5 (q, J C-F ) 271.2 Hz), 125.1 (m), 130.1,
132.6 (q, J C-F ) 32.2 Hz), 134.8 (apparent t, J app ) 22.2 Hz),
134.9 (apparent t, J app ) 5.1 Hz), 135.0 (apparent t, J app ) 6.7
Hz), 152.1, additional resonances not resolved; 19F NMR
(CDCl3) δ -63.2; 31P NMR (CDCl3) δ 22.9. Anal. Calcd for
C
49H31F18IP2Pd: C, 46.82; H, 2.49. Found: C, 46.81; H, 2.59.
(4-F lu or op h en yl)P d [P (4-(t r iflu or om et h yl)p h en yl)3]2I
(1w ). Syn th esized fr om 2. The above general procedure
was followed by utilizing 92.0 mg (0.0925 mmol) of 2, 41.1 mg
(0.185 mmol) of 4-fluoroiodobenzene, and 172.4 mg (0.370
mmol) of tris(4-(trifluoromethyl)phenyl)phosphine to yield
0.187 g of 1w as pale yellow, feathery crystals (0.148 mmol,
80%): 1H NMR (CDCl3) δ 6.12 (apparent t, J app ) 8.9 Hz, 2H),
6.39 (m, 2H), 7.60 (m, 24H); 13C NMR (CDCl3) δ 115.9 (d, J C-F
1
1
detectable impurities other than trapped methanol by H and
) 19.6 Hz), 123.4 (q, J C-F ) 271.1 Hz), 125.2 (q, J C-F ) 3.7
31P NMR: 1H NMR (DMSO-d6) δ 3.57 (s, 3H), 6.30 (apparent
t, J app ) 7.7 Hz, 1H), 6.84 (d, J ) 7.7 Hz, 1H), 6.89 (br d, J )
7.7 Hz, 1H), 6.92 (br s, 1H), 7.26 (m, 8H), 7.31 (m, 12 H), 7.44
(apparent t, J app ) 7.7 Hz, 2H), 7.71 (d, J ) 7.7 Hz, 2H), 7.82
(br d, J ) 7.7 Hz, 2H), 7.98 (br s, 2H); 13C NMR (DMSO-d6) δ
51.3, 122.7, 126.3, 127.8, 128.0, 128.8, 129.8, 130.8 (br), 133.9,
136.0, 136.7, 139.0, 148.0, 166.0, additional resonances not
Hz), 123.9 (q, J C-F ) 32.7 Hz), 134.5 (apparent t, J app ) 23.0
Hz), 135.0 (apparent t, J app ) 6.6 Hz), 135.4 (q, J C-F ) 5.7
Hz), 149.8, 160.7 (d, 1J C-F ) 245.7); 19F NMR (CDCl3) δ -122.3
(s, 1F), -61.5 (s, 18F); 31P NMR (CDCl3) δ 22.9. (J P-F ) 4.5
Hz). Anal. Calcd for C48H28F19IP2Pd: C, 45.72; H, 2.24.
Found: C, 45.38; H, 2.30.
(P en t a flu or op h en yl)P d [P (4-(t r iflu or om et h yl)p h en -
yl)3]2I (1x). Syn th esized fr om 2. The above general pro-
cedure was followed by utilizing 92.0 mg (0.0925 mmol) of 2,
54.3 mg (0.185 mmol) of iodopentafluorobenzene, and 172.4
mg (0.370 mmol) of tris(4-(trifluoromethyl)phenyl)phosphine
to yield 49.0 mg of 1x as bright yellow cubic crystals (0.0367
mmol, 20%): 1H NMR (CDCl3) δ 7.50 (d, J ) 8.1 Hz, 12H),
7.70 (m, 12H); 13C NMR (CDCl3) δ 123.3 (q, 1J C-F ) 271.2 Hz);
resolved; 31P NMR (DMSO-d6) δ 24.8. Anal. Calcd for C44H35
-
INa2O8P2PdS2: C, 48.17; H, 3.21. Found: C, 48.73; H, 3.26.
((4-Me t h o x y c a r b o n y l)p h e n y l)P d [P (C 6 H 5 )2 (4-S O 3 -
KC6H4)]2I (1bb). The above procedure for 1a a was employed
using Pd2(dba)3‚C6H6 (2) (0.150 g, 0.151 mmol) 5 (0.232 g, 0.583
mmol) and methyl 4-iodobenzoate (0.082 g, 0.310 mmol). This
yielded 0.322 g of complex 1bb (0.285 bbb, 95%), which was
then recrystallized from aqueous THF by quickly adding just
enough water to a warm (ca. 50 °C) THF suspension (ca. 10
mL of THF) to dissolve the complex. The solution was rapidly
cooled to -20 °C to yield pale yellow-green leaves as a mono-
THF solvate. Lyophilization from water gave a solvate-free
powder: 1H NMR (CD3OD) δ 3.73 (s, 3H), 6.80 (dm, J ) 7.9
Hz, 2H), 6.86 (d, J ) 7.9 Hz, 2H), 7.28 (m, 8H), 7.38 (m, 4H),
7.54 (m, 12H), 7.70 (d, J ) 8.1 Hz, 4H); 13C NMR insufficient
125.3 (m), 133.5 (q, J C-F ) 32.9 Hz), 134.0 (apparent t, J app
)
24.7 Hz), 134.7 (apparent t, J app ) 6.6 Hz), additional reso-
nances not resolved; 19F NMR (CDCl3) δ -160.0 (apparent t,
J app ) 21.7Hz, 2F), -158.8 (t, J ) 19.0 Hz, 1F), -117.8 (d, J
) 24.8 Hz, 2F), -61.6 (s, 18F); 31P NMR (CDCl3) δ 22.2. Anal.
Calcd for C48H24F23IP2Pd: C, 43.25; H, 1.81. Found: C, 43.47;
H, 2.12.
(4-Met h ylp h en yl)P d [(et h yl)P (p h en yl)2]2I (1y). Syn -
th esized fr om 3. The above general procedure was applied
using 39.4 mg (0.185 mmol) of 3, 40.4 mg (0.185 mmol) of
4-iodotoluene, and 79.3 mg (0.370 mmol) of ethyldiphenylphos-
phine to yield 1y as a greenish-white precipitate: 1H NMR
(CDCl3) δ 0.86 (dt, J ) 8.3 Hz, J ) 7.5 Hz, 6H), 2.04 (s, 3H),
2.06 (m, 4H), 6.35 (d, J ) 7.6 Hz, 2H), 6.41 (m, 2H), 7.26 (m,
8H), 7.33 (apparent t, J app ) 7.2 Hz, 4H), 7.48 (m, 8H); 13C
NMR (CDCl3) δ 9.1, 20.5, 22.5 (apparent t, J app ) 14.3 Hz),
solubility; 31P NMR (CD3OD) δ 22.3; Anal. Calcd for C44H35
-
IK2O8P2PdS2: C, 45.33; H, 2.83. Calcd for the monohydrate:
C, 44.63; H, 2.96. Found: C, 45.02; H, 3.38.
((4-Me t h o x y c a r b o n y l)p h e n y l)P d [As (C6H 5)2(4-S O 3-
KC6H4)]2I (1cc). An identical procedure employing Pd2-
(dba)3‚C6H6 (2) (0.150 g, 0.151 mmol), 6 (0.259 g, 0.610 mmol),
and methyl 4-iodobenzoate (0.082 g, 0.310 mmol) yielded 0.307
g of complex 1cc (0.252 mmol, 84%). This material was

3716 Organometallics, Vol. 15, No. 17, 1996
Wallow et al.
recrystallized from aqueous THF to yield pale yellow leaves
as a mono-THF solvate. Lyophilization from water gave a
solvate-free powder: 1H NMR (CD3OD) δ 3.75 (s, 3H), 6.87
(d, J ) 7.8 Hz, 2H), 6.94 (d, J ) 7.8 Hz, 2H), 7.31 (m, 4H),
7.39 (m, 2H), 7.45 (multiple resonances, 6H), 7.73 (d, J ) 8.0
Hz, 2H); 13C NMR insufficient solubility. Anal. Calcd for
phosphide anion was generated rapidly. The solution was
stirred for 1 h. Excess potassium was removed under an argon
back-flush. The flask was equipped with an oven-dried
condenser, and potassium 4-fluorobenzenesulfonate (2.21 g,
10.5 mmol) was added. The solution was heated at reflux
under argon until colorless, ca. 5 h. Workup proceeded by
pouring the cooled reaction mixture into 150 mL of water. The
resulting aqueous solution was washed twice with 50 mL of
ether and then concentrated to yield a white solid. Crystal-
lization from degassed water yielded 2.64 g of 5 as a stable
hydrate (6.63 mmol, 66%): 1H NMR (DMSO-d6) δ 7.22 (m, 3
H), 7.37 (m, 3 H), 7.62 (m, 1 H); 13C NMR (DMSO-d6) δ 125.8
C
44H35As2IK2O8PdS2: C, 43.42; H, 2.90. Found: C, 43.63; H,
2.84.
(4-Nitr op h en yl)P d [P (C6H5)2(4-SO3KC6H4)]2I (1d d ). An
identical procedure employing Pd2(dba)3‚C6H6 (2) (0.100 g,
0.101 mmol), 5 (0.155 g, 0.390 mmol), and 4-iodonitrobenzene
(0.052 g, 0.206 mmol) yielded 0.232 g of complex 1d d (0.199
mmol, 99%). A portion of this material was recrystallized from
aqueous THF to yield pale yellow-green leaves as a mono-THF
solvate. Lyophilization of the solvate from 90:10 water:
methanol gave a solvate-free powder in 99% recovery based
on the crude material: 1H NMR (CD3OD) δ 6.92 (dm, J ) 8.8
Hz, 1H), 7.04 (d, J ) 8.8 Hz, 1H), 7.35 (m, 4H), 7.45 (m, 2H),
7.56 (m, 6H), 7.86 (m, 4H); 13C NMR insufficient solubility;
31P NMR (CD3OD) δ 23.5. Anal. Calcd for C42H32IK2NO8P2-
PdS2: C, 45.19; H, 2.89; N, 1.25. Calcd for the monohydrate:
C, 44.47; H, 3.02; N, 1.23. Found: C, 44.80; H, 3.21; N, 1.47.
(4-(Tr iflu or om e t h yl)p h e n yl)P d [P (C6H 5)2(4-SO3KC6-
H4)]2I (1ee). An identical procedure employing Pd2(dba)3‚C6H6
(2) (0.100 g, 0.101 mmol), 5 (0.155 g, 0.390 mmol), and
4-iodobenzotrifluoride (0.056 g, 0.206 mmol) yielded 0.227 g
of complex 1ee (0.199 mmol, 98%). A portion of this material
was recrystallized from aqueous THF to yield pale yellow-
green crystals as a mono-THF solvate. Lyophilization of the
solvate from 90:10 water:methanol gave a solvate-free powder
in 83% recovery based on the crude material: 1H NMR (CD3-
OD) δ 6.44 (d, J ) 8.1 Hz, 1H), 6.77 (d, J ) 8.1 Hz, 1H), 7.27
2
2
(d, J C-P ) 7.0 Hz), 128.8 (d, J C-P ) 7.2 Hz), 129.0 (s), 132.7
1
1
3
(d, J C-P ) 19.7 Hz), 133.2 (d, J C-P ) 19.5 Hz), 136.5 (d, J CP
) 11.4 Hz), 137.1 (d, J CP ) 11.6 Hz), 148.7 (s); 31P NMR
3
(DMSO-d6) δ -6.03; MS (FAB) (m/z) 380 (MH+), 419 (MK+).
Anal. Calcd for C18H16KPO4S: C, 54.32; H, 4.05. Found: C,
54.41; H, 4.04.
As(C6H5)2(4-SO3KC6H4) (6). To an oven-dried, argon-
flushed 250 mL Schlenk flask equipped with a glass-coated
stir bar was added 1.380 g of potassium (35.4 mmol) and 50
mL of DME. A solution containing 3.38 g of As(C6H5)3 (11.0
mmol) in 50 mL of DME was added via an addition funnel,
and the mixture was stirred at room temperature for ca. 10
h. Excess potassium was removed under an argon back-flush.
The flask was fitted with an addition funnel charged with
4-fluorobenzenesulfonic acid in toluene (29 mL of a 0.373 M
stock). Upon cooling of the reaction to -78 °C, the acid
solution was added dropwise over 15 min. Following addition,
the reaction flask was allowed to warm to room temperature,
equipped with an oven-dried condenser, and heated to reflux
under argon until colorless, ca. 4 h. Workup proceeded exactly
as for 11 to yield 2.904 g of 12 (6.84 mmol, 62%): 1H NMR
(DMSO-d6) δ 7.24 (d, J ) 8.2 Hz, 1 H), 7.27 (m, 2 H), 7.37 (m,
3 H), 7.62 (d, J ) 8.2 Hz, 1 H); 13C NMR (DMSO-d6) δ 125.9,
128.7, 128.9, 132.7, 133.2, 138.8, 139.4, 148.5; MS (FAB) (m/
z) 425 (MH+), 463 (MK+). Anal. Calcd for C18H14AsKO3S: C,
50.94; H, 3.33. Found: C, 50.59; H, 3.38.
(m, 4H), 7.38 (m, 2H), 7.44 (m, 4H), 7.66 (m, 2H), 7.77 (d, J )
1
8.1 Hz, 2H); 13C NMR (CD3OD) δ 124.6 (m), 125.8 (q, J C-F
)
269.9 Hz), 126.2 (apparent t, J app ) 5.2 Hz), 129.1 (apparent
t, J app ) 5.2 Hz), 131.5, 131.7 (q, J C-F ) 23.6 Hz), 135.6
2
(apparent t, J app ) 6.2 Hz), 136.0 (apparent t, J app ) 6.5 Hz),
136.8 (br), 147.2, additional resonances not resolved; 19F NMR
(CD3OD) δ -61.35; 31P NMR (CD3OD) δ 23.8. Anal. Calcd
for C43H32F3IK2O6P2PdS2: C, 45.33; H, 2.83. Calcd for the
monohydrate: C, 44.63; H, 2.96. Found: C, 44.89; H, 3.16.
Liga n d Syn th esis. P (C6H5)2(4-SO3KC6H4) (5). To an
oven-dried, argon-flushed 250 mL Schlenk flask equipped with
a stir bar were added 50 mL of THF and 1.00 g of potassium
(25.3 mmol). A solution containing 2.20 g of chlorodiphe-
nylphosphine (10.0 mmol) in 20 mL of THF was added
dropwise over the course of 10 min via an addition funnel.
Following a brief induction period, the bright orange-red
Ack n ow led gm en t. We gratefully thank the Na-
tional Science Foundation (U.S.), the Office of Naval
Research, and Lawrence Berkeley Laboratories for
funding this research. T.I.W. thanks the U.S. Depart-
ment of Education, Dow Chemical, and IBM for fellow-
ship support. Similarly, F.E.G. thanks the U.S. De-
partment of Education for a graduate fellowship.
OM9602567