Synthesis and Reactivity of Ortho-Mercuriated and Orthio-Palladated Arylacetals and Cyclic and Acyclic Aryldithioacetals. New Examples of the Rearrangement of Acyclic Dithioacetal Aryl- to Dithioether Alkyl-Palladium Complexes

Article abstract of DOI:10.1021/om0342964

The synthesis of ortho-palladated complexes by transmetalation reactions was studied using arylmercurials, by oxidative additions of the haloarenes to palladium(0) species. Orthopalladated amines or imines were synthesized by reacting them with palladium acetate. The reactions with isocyanides giving complexes were studied resulting after mono or tri-insertion. The greater trans influence of the aryl with respect to the chloro ligand caused the Pd-N(2) distance to be longer than the PdN(1) bond length.

Full text of DOI:10.1021/om0342964

1292
Organometallics 2004, 23, 1292-1304
Syn th esis a n d Rea ctivity of Or th o-Mer cu r ia ted a n d
Or th o-P a lla d a ted Ar yla ceta ls a n d Cyclic a n d Acyclic
Ar yld ith ioa ceta ls. New Exa m p les of th e Rea r r a n gem en t
of Acyclic Dith ioa ceta l Ar yl- to Dith ioeth er
Alk yl-P a lla d iu m Com p lexes
J ose´ Vicente,*,† J ose´-Antonio Abad,*,† Francisco S. Herna´ndez-Mata, and
Barbara Rink
Grupo de Qu´ımica Organometa´lica, Departamento de Qu´ımica Inorga´nica, Facultad de
Quı´mica, Universidad de Murcia, Apartado 4021, E-30071 Murcia, Spain
Peter G. J ones‡
Institut fu¨r Anorganische und Analytische Chemie der Technischen Universita¨t, Postfach 3329,
38023 Braunschweig, Germany
M. Carmen Ram´ırez de Arellano§
Departamento de Quı´mica Orga´nica, Facultad de Farmacia, Universidad de Valencia,
46100 Valencia, Spain
Received November 13, 2003
The arylmercurial [Hg{C6H3(CHO)2-2,5}Cl] (1) reacts with CH(OMe)3 or HS(CH2)2SH to
give [Hg{C6H3{CH(OMe)2}2-2,5}Cl] (2) or [Hg(Ara)Cl] [Ara ) C6H3{CH(SCH2CH2S)}2-2,5 (3a )],
respectively. The mercurial 2 or 3a reacts with (NMe4)2[Pd2Cl6] and 2,2′-bipyridine (bpy) or
with trans-[PdCl2(PPh3)2] to give the aryl-palladium complex [Pd{C6H3{CH(OMe)2}2-2,5}-
Cl(bpy)] (4) or [Pd(κ2-C,S-Ara)Cl(PPh3)] (5a *), respectively. The reaction of 1 with NaI3 renders
IC6H3(CHO)2-2,5 (6), which reacts with HS(CH2)2SH to give IAra (7a ). Similarly, IC6H(OMe)3-
2,3,4-(CHO)-6 (8) reacts with HS(CH2)2SH or ToSH (To ) C6H4Me-4) to give the correspond-
ing dithioacetals IArb [Arb ) C6H(OMe)3-2,3,4-{CH(SCH2CH2S)}-6 (7b)] or IC6H(OMe)3-2,3,4-
CH(STo)2-6 (9). The iodoarene 7a or 7b adds oxidatively to “Pd(dba)2” (dba ) dibenzylideneace-
tone) to give [Pd(κ2-C,S-Ar)(µ-I)]2 [Ar ) Ara (10a ), Arb (10b)], which, in turn, reacts (i) with
1 equiv of PPh3 to give [Pd(κ2-C,S-Ar)I(PPh3)] [Ar ) Ara (5a ), Arb (5b)], (ii) with Tl(TfO)
(TfO ) CF3SO3) and PPh3 (1:2:4 molar ratio) to give [Pd(κ2-C,S-Arb)(PPh3)2]TfO (11b), or
(iii) with 1 equiv of Tl(TfO) and bpy (1:2:2 molar ratio) to give [Pd(κ2-C,S-Arb)(bpy)]TfO (11b*).
Complexes 10 react with 1 equiv of isonitriles to give, after a short period of reaction, the
complexes [Pd(κ2-C,S-Ar)I(CNR)] [Ar ) Ara, R ) Xy ) 2,6-dimethylphenyl (12a ), tBu (12a ′);
t
Ar ) Arb, R ) Bu (12b′)]. The iminoacyl complexes [Pd(κ2-C,S-Im)(µ-I)]2 [Im ) Ima (13a ),
Imb (13b)] can be obtained by stirring a solution of 12a for 5 days to give 13a or by reacting
10b with XyNC in 1:1 molar ratio during 22 h to give 13b. Complexes 10 react with 2 equiv
of isonitriles to give the iminoacyl complexes [Pd(κ2-C,S-Im)I(CNR)] [Im ) C(dNR)C6H3-
t
{CH(SCH2CH2S)}2-2,5, R ) Xy, Im ) Ima (14a ), R ) Bu, Im ) Ima′ (14a ′); Im ) C(dNR)-
t
C6H(OMe)3-2,3,4-(SCH2CH2S)-6, R ) Xy, Im ) Imb (14b), R ) Bu, Im ) Imb′ (14b′)].
Complexes 14a ,b react with 10a ,b in 2:1 molar ratio to give 13a ,b. Complexes 10a ,b react
with XyNC and Tl(TfO) (1:4:1) to give the dimeric cations [Pd{(κ2-C,S-Im)(CNXy)}2(µ-I)]-
TfO [R ) Xy, Im ) Ima (15a ), Imb (15b)]. The compound [Pd{κ2-C,S-Arc}(µ-I)]2 (16) reacts (i)
with PPh3 and Tl(TfO) in 1:4:2 molar ratio to give [PdII(κ2-C,S-Arc)(PPh3)2]TfO T [Pd0{η2-
κ3-C,S,S-S(To)dCHC6H(STo)-2-(OMe)3-3,4,5}(PPh3)2]TfO (17), (ii) with isonitriles in 1:2 or
t
1:4 molar ratio yielding complexes [Pd(κ2-C,S-Arc)I(CNR)] [R ) Xy (18), R ) Bu (18′)] or
trans-[Pd(κ1-C-Arc)I(CNR)2] [R ) Xy (19), R ) tBu (19′)], respectively, and (iii) with PPh3 in
1:2 molar ratio yielding [Pd(κ2-C,S-Arc)I(PPh3)] (20). The iodoarene 9 reacts with Pd(dba)2
(i) and PPh3 (1:1:1 molar ratio) to give [Pd{κ2-C,S-Arc)I(PPh3)] [Arc ) CH(STo)C6H(STo)-2-
(OMe)3-3,4,5(20)]and (ii)PPh3 and Tl(TfO)(1:1:2:1molar ratio)togive17.Thecrystaland molecular
structures of 4, 5a *, 14a , and 14b have been determined by X-ray diffraction studies.
In tr od u ction
stoichiometric5-16 organic synthesis, for chiral recogni-
tion,17 as chiral resolving agents,18,19 as antitumorals,20
or advanced materials.21 Ortho-palladated complexes
are also involved in interesting dendritic systems.22 We
have reported the synthesis of ortho-palladated com-
plexes by transmetalation reactions, using arylmercu-
rials, by oxidative additions of the corresponding ha-
loarenes to palladium(0) species, or through ortho-
palladation processes. The first method has allowed us
to prepare aryl-palladium complexes bearing CHO,23-25
The interest in ortho-palladated complexes arises
from their potential applications in catalytic1-4 and
Dedicated to Professor Helmut Werner on the occasion of his 70th
birthday and in recognition of his leading role in organometallic
chemistry.
† E-mail: jvs@um.es (J .V.); jaab@um.es (J .A.A.). Web: http://ww-
w.um.es/gqo/.
‡ Corresponding author regarding the X-ray diffraction study of 14a
and 14b. E-mail: p.jones@tu-bs.de.
§ Corresponding author regarding the X-ray diffraction study of 4
and 5a *. E-mail: mcra@uv.es.
10.1021/om0342964 CCC: $27.50 © 2004 American Chemical Society
Publication on Web 02/18/2004

Ortho-Mercuriated and -Palladated Arylacetals
Organometallics, Vol. 23, No. 6, 2004 1293
CHdNOH, CO2H,25 C(O)Me,24 C(O)NHtBu,15 CH2OEt,8
or NO2 groups in ortho-position. By means of the
indenones,9,10,13,14 or spirocyclic compounds.8,10-12,15
We have also studied reactions with isocyanides
giving complexes resulting after mono- or tri-in-
sertion6,15,30,31,37-39 or organic products such as a keten-
imine,15 2-substituted-aminoisoindolinium salts,6 2,3-
dihydroisoindol-1-ones, benzamides, acetamides, or ac-
26
oxidative addition method we have prepared complexes
with the ortho substituents NH2,27-30 OH, OC(O)Me,
OC(O)CHdCH231 CHdCHR [R ) H,14 Ph, 2-pyridyl, Cl,
CHO, C(O)Me]32 or CN.14 We have also prepared ortho-
palladated amines or imines by reacting them with
palladium acetate.25,33,34 Many of these complexes show
interesting properties. Thus, some of them insert alkynes
to give alkenyl-8-11,13-15,32,33,35-37 or indenyl-palladium
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1294 Organometallics, Vol. 23, No. 6, 2004
Vicente et al.
Ch a r t 1
While many aryl S,C,S-pincer complexes have been
reported,2,4,40-43 a limited number of C-S ortho-palla-
dated complexes are known.3,7,16,41,44,45 Some of them are
active catalysts for C-C coupling reactions.3,16,45 We
report here two families of C-S ortho-palladated com-
plexes and also C-S iminoacyl- and alkyl-palladium
complexes.
Exp er im en ta l Section
The elemental analyses, conductivity measurements in
acetone, and melting point determinations were carried as
described previously.46 The NMR spectra were measured at
room temperature, unless otherwise stated. Chart 2 shows the
notation used for the various organyl groups. The compounds
“Pd(dba)2”47 ([Pd2(dba)3]‚dba, dba ) dibenzylideneacetone),
[Hg{C6H3(CHO)2-2,5}Cl] (1),25 IC6H(OMe)3-2,3,4-CHO-6 (8),48
IC6H(OMe)3-2,3,4-CH(STo)2-6 (9),41 and [Pd{κ2-C,S-Arc}(µ-I)]2
(16)41 were prepared as reported previously. Unless otherwise
stated, reactions were carried out without special precautions
against moisture or light.
etamidic acids,39 and with CO to give aroyl-palladium
complexes,28-31,37,39 3-methylenephthalides and 3-ethoxy-
3-methyl-3H-isobenzofuran-1-one39 or, in the presence
of O2, palladium benzoate complexes.28,29
Syn th esis of [Hg{C6H3{CH(OMe)2}2-2,5}Cl] (2). The
mercurial 1 (504 mg, 1.354 mmol) was reacted under nitrogen
for 24 h at room temperature with HC(OMe)3 (15 mL, degassed
and saturated with nitrogen) and with 96% sulfuric acid (50
µL) in anhydrous methanol (20 mL). Saturated aqueous
NaHCO3 (50 mL) and Cl2CH2 (60 mL) were added, and the
mixture was shaken. The organic phase was separated and
washed twice with 25 mL of a saturated aqueous NaHCO3.
The separated organic phase was dried over MgSO4 and
filtered. The solvent was evaporated to dryness, the resulting
pale yellow oil was dissolved in Et2O (2 mL), and then,
n-pentane (15 mL) and n-hexane (5 mL) were added. The
solvent was evaporated and the residue triturated with
n-pentane (3 mL). The solution was decanted and the residue
triturated again with n-pentane (3 mL). This operation was
repeated several times. The final residue was dried in vacuo
to give a pale yellow solid. Yield: 415 mg, 66%. Mp: 61 °C. IR
(cm-1): ν(Hg-Cl) 345. 1H NMR (300 MHz, CDCl3): δ 7.51 (m,
We have reported that certain 2,3,4-trimethoxy-6-
formylphenylpalladium complexes undergo a rare re-
arrangement, involving a positional change between the
formyl group and the palladium moiety with breaking
and reforming of C-C and C-Pd bonds, to give the
corresponding 3,4,5-trimethoxy-2-formylphenylpalladi-
um isomers (Chart 1).23,24,40 Similarly, when we pre-
pared the first ortho-palladated acyclic dithioacetals, a
new type of rearrangement involving the cleavage of
alkyl-S and aryl-Pd bonds and formation of aryl-S
and alkyl-Pd bonds was observed (Chart 1).41 In the
present work we describe new related results, some of
which have been recently communicated.42 In addition,
we report the synthesis of the first ortho-palladated
cyclic dithioacetal. We designed the synthesis of these
complexes, prepared through transmetalation and oxi-
dative addition reactions, to see if the same or similar
rearrangents to that observed with the acyclic dithio-
acetals could be observed.
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S. J .; Shimizu, G. K. H.; Wisner, J . A. Organometallics 1998, 17, 2324.
van Manen, H. J .; Nakashima, K.; Shinkai, S.; Kooijman, H.; Spek, A.
L.; van Veggel, F.; Reinhoudt, D. N. Eur. J . Inorg. Chem. 2000, 2533.
Takahashi, S.; Nonoyama, M.; Kita, M. Transition Met. Chem. 1995,
20, 528. Bacsa, J .; Moutloali, R. M.; Darkwa, J . Acta Crystallogr., Sect.
C 2002, 58, 109.
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Ramirez de Arellano, M. C.; J ones, P. G. Organometallics 2002, 21,
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(31) Vicente, J .; Abad, J . A.; Fo¨rtsch, W.; J ones, P. G.; Fischer, A.
K. Organometallics 2001, 20, 2704.
(32) Vicente, J .; Abad, J . A.; Bergs, R.; Ram´ırez de Arellano, M. C.;
Mart´ınez-Viviente, E.; J ones, P. G. Organometallics 2000, 19, 5597.
(33) Vicente, J .; Saura-Llamas, I.; Palin, M. G.; J ones, P. G. J . Chem.
Soc., Dalton Trans. 1995, 2535.
(34) Vicente, J .; Saura-Llamas, I.; J ones, P. G. J . Chem. Soc., Dalton
Trans. 1993, 3619. Vicente, J .; Saura-Llamas, I.; Palin, M. G.; J ones,
P. G.; Ram´ırez de Arellano, M. C. Organometallics 1997, 16, 826.
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Arellano, M. C. Organometallics 1996, 15, 1422.
(37) Vicente, J .; Saura-Llamas, I.; Turp´ın, J .; Ram´ırez de Arellano,
M. C.; J ones, P. G. Organometallics 1999, 18, 2683.
(38) Vicente, J .; Abad, J . A.; Mart´ınez-Viviente, E.; J ones, P. G.
Organometallics 2002, 21, 4454.
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Organometallics 2003, 22, 1967.
(40) Vicente, J .; Abad, J . A.; Stiakaki, M. A.; J ones, P. G. J . Chem.
Soc., Chem. Commun. 1991, 137.
(44) Dupont, J .; Beydoun, N.; Pfeffer, M. J . Chem. Soc., Dalton
Trans. 1989, 1715. Campora, J .; Lopez, J . A.; Palma, P.; del Rio, D.;
Carmona, E.; Valerga, P.; Graiff, C.; Tiripicchio, A. Inorg. Chem. 2001,
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Ebeling, G.; Burrow, R. A. Organometallics 2001, 20, 171.
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N. J ., Ed.; Wiley & Sons: New York, 1956; Vol. 36, p 46.

Ortho-Mercuriated and -Palladated Arylacetals
Organometallics, Vol. 23, No. 6, 2004 1295
Ta ble 1. Su m m a r y of X-r a y Da ta for Com p ou n d s 4, 5a *, 14a , a n d 14b
4
5a *
14a ‚CH2Cl2
14b
formula
cryst habit
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
C
22H25ClN2O4Pd
C30H28ClPPdS4
yellow prism
9.5507(8)
10.4225(10)
15.9744(12)
102.645(6)
102.112(6)
102.782(8)
1456.3(2)
2
C31H33Cl2IN2PdS4
yellow tablet
12.1236(8)
19.9017(14)
14.5596(10)
90
100.062(3)
90
3458.9
C30H33INO2O3PdS2
pale yellow prism
9.2584(5)
9.9373(6)
13.2560(9)
84.966(5)
82.327(5)
62.438(3)
1071.04(11)
2
yellow tablet
18.4714(16)
17.5311(14)
18.5995(16)
90
96.634(3)
90
5982.6
Z
4
8
T (K)
173
173
143
143
space group
cryst size
P1h
P1h
P21/n
C2/c
0.62 × 0.34 × 0.32
0.58 × 0.56 × 0.42
0.46 × 0.22 × 0.14
0.19 × 0.13 × 0.08
µ (mm-1
2θ(max)
)
1.023
50
1.573
50
1.85
1.83
56.6
60
no. of total/indep reflns
Rint
4944/3736
0.0270
1.05
10 110/5055
0.0114
1.08
65 083/8582
0.061
1.04
24 855/8711
0.065
0.88
S(F2)
wR2 [all reflns]
R1 [I>2σ(I)]
0.0893
0.0334
0.0605
0.0228
0.0614
0.0248
0.0524
0.0298
Syn th esis of [P d {C6H3{CH(OMe)2}2-2,5}Cl(bp y)] (4).
The mercurial 2 (313 mg, 0.68 mmol), (NMe4)2[Pd2Cl6] (240
mg, 0.42 mmol), and NMe4Cl (120 mg, 1.1 mmol) were mixed
under nitrogen in anhydrous acetone (30 mL), and the result-
ing mixture was stirred for 1 h at room temperature and for
a further 4.5 h at 0 °C. The suspension was filtered over Celite
into an acetone (5 mL) solution of 2,2′-bipyridine (131 mg, 0.84
mmol). From this moment it is not necessary to work under
nitrogen. The resulting mixture was stirred for 45 min, the
solvent evaporated to dryness, and the residue treated with
Cl2CH2 (35 mL). The mixture was filtered over Celite and the
corresponding solution concentrated (ca. 2 mL). Then Et2O (30
mL) and n-hexane (50 mL) were added, causing the precipita-
tion of a yellow solid, which was filtered, washed with
n-hexane, and air-dried to give 4 as a yellow solid. Yield: 287
mg, 81%. Mp: 195 °C (dec). 1H NMR (300 MHz, CDCl3): δ
9.29 (m, 1 H, bpy), 8.1-7.1 (m, 10 H), 6.36 (s, CH(OMe)2, 1
H), 5.37 (s, CH(OMe)2, 1 H), 3.43 (s, MeO, 3 H), 3.34 (s, MeO,
3 H), 3.33 (s, MeO, 3 H), 3.16 (s, MeO, 3 H). 13C NMR (75 MHz,
CDCl3): δ 155.9 (quaternary C), 153.4 (quaternary C), 152.5
(CH), 150.5 (quaternary C), 149.6 (CH), 141.8 (quaternary C),
139.0 (CH), 138.4 (CH), 136.5 (quaternary C), 132.6 (CH), 126.4
(CH), 126.2 (CH), 125.4 (CH), 122.1 (CH), 121.7 (CH), 121.2
(CH), 106.7 (CH(OMe)2), 103.6 (CH(OMe)2), 54.9 (MeO), 53.4
(MeO), 52.9 (MeO), 52.8 (MeO). Anal. Calcd for C22H25N2ClO4-
Pd: C, 50.50; H, 4.82, N, 5.35. Found: C, 50.68; H, 4.66, N,
5.29. Single crystals were grown by slow diffusion of Et2O into
a solution of 4 in acetone.
Syn th esis of [P d (K2-C,S-Ar a )Cl(P P h 3)] (5a *). The mercu-
rial 3a (210 mg, 0.40 mmol), [PdCl2(PPh3)2] (236 mg, 0.34
mmol), and NMe4Cl (76 mg, 0.69 mmol) were added to a
solvent system consisting of anhydrous acetone (30 mL) and
1,4-dioxane (10 mL). The resulting mixture was heated at 76
°C under nitrogen for 7 h. The mixture was cooled to room
temperature and filtered over Celite. The solvent was evapo-
rated to dryness, and the residue was treated with Cl2CH2 (25
mL) and filtered over Celite. The filtrate was concentrated (to
ca. 3 mL), affording a yellow precipitate, which was filtered,
washed with Et2O (2 × 2 mL), and air-dried, giving impure
[PdCl2(PPh3)2] (48 mg). A mixture of Et2O (15 mL), n-pentane
(5 mL), and n-hexane (2 mL) was added to the mother liquor,
and the resulting mixture was slightly concentrated, causing
the precipitation of a solid, which was filtered and chromato-
graphed on Al2O3 using an acetone/CH2Cl2 mixture to give
yellow 5a *, containing minute amounts of the mercurial 3a
shown in 1H NMR spectrum. This could explain the slightly
low C analysis found (relative error, -1.26%). Yield: 148 mg,
64%. Mp: 214 °C (dec). 1H NMR (300 MHz, CDCl3, room
temperature): δ 7.76-7.69 (m, 6 H), 7.46-7.33 (m, 9 H), 7.06
Ch a r t 2
3
3
H6, 1 H), 7.44 (d, H3 1 H, J HH ) 9 Hz), 7.41 (dd, H4, J HH
)
9 Hz, 4J HH ) 2 Hz), 5.38 (s, CH(OMe)2, 1 H), 5.34 (s, CH(OMe)2,
1 H), 3.35 (s, 2 Me, 6 H), 3.33 (s, 2 Me, 6 H). 13C NMR (75
MHz, CDCl3): δ 143.1 (quaternary C), 139.0 (quaternary C),
135.1 (CH), 128.3 (CH), 127.0 (CH), 103.7 (CH(OMe)2), 102.6
(CH(OMe)2), 53.5 (2 Me), 52.7 (2 Me). The signal corresponding
to C-Hg was not observed. Anal. Calcd for C12H17ClHgO4: C,
31.24; H, 3.71. Found: C, 31.26; H, 3.60.
Syn th esis of [Hg(Ar a )Cl] (3a ). A solution of 2 (215 mg,
0.47 mmol) in anhydrous toluene (8 mL) was cooled to 0 °C
under nitrogen. Then, HS(CH2)2SH (79 µL, 0.94 mmol) and
some crystals of p-toluenesulfonic acid were added. The
mixture was stirred for 20 h, allowing it to reach room
temperature slowly. In this way colorless 3a precipitated. It
was filtered, washed with pentane (10 mL), and air-dried.
Yield: 174 mg, 72%. Mp: 195 °C (dec). IR (cm-1): ν(Hg-Cl)
1
4
331. H NMR (200 MHz, d6-DMSO): δ 7.77 (d, H6, 1 H, J HH
3
) 2 Hz), 7.41 (d, H3, 1 H, J HH ) 8 Hz), 7.32 (dd, H4, 1 H,
3J HH ) 8 Hz, J HH ) 2 Hz), 5.87 (s, CHS2, 1 H), 5.69 (s, CHS2,
4
1 H), 3.7-3.3 (m, CH2, 8 H). 13C NMR (50 MHz, d6-DMSO): δ
152.3 (quaternary C), 141.2 (quaternary C), 139.9 (quaternary
C), 136.7 (CH), 129.9 (CH), 127.1 (CH), 59.0 (CHS2), 54.7
(CHS2), 39.8 (b, 4×CH2). Anal. Calcd for C12H13ClHgS4: C,
27.64; H, 2.51. Found: C, 27.76; H, 2.52.

1296 Organometallics, Vol. 23, No. 6, 2004
Vicente et al.
(d, H3, 1 H, 3J HH ) 8 Hz), 6.96 (dd, H4, 1 H, 3J HH ) 8 Hz, 4J HH
The resulting suspension was filtered, and the solid was
washed with water and air-dried, giving a yellow solid, which
was treated with Et2O (60 mL). The resulting mixture was
filtered over Celite, and the solvent was evaporated to dryness.
The residue was triturated with n-pentane (4 mL), filtered,
washed with n-pentane (2 mL), and air-dried to give pale
yellow 6. Yield: 585 mg, 69%. IR (cm-1): ν(CdO) 1695 vs, b.
4
) 2 Hz), 6.64 (d, H6, 1 H, J HH ) 2 Hz), 5.79 (s, CHS2, 1 H),
4.82 (s, CHS2, 1 H), 4.5-4.35 (m, CH2, 2 H), 3.55-3.35 (m,
CH2, 2 H), 3.03 (m, 2×CH2, 4 H). At -55 °C: 7.78-7.71 (m, 6
3
H), 7.56-7.38 (m, 9 H), 7.13 (d, H3, 1 H, J HH ) 8 Hz), 7.00
3
4
(apparent d, H4, 1 H, J HH ) 8 Hz), 6.62 (d, H6, 1 H, J HH
)
4
2 Hz), 5.83 (d, CHS2, 1 H, J PH ) 4.5 Hz), 4.81 (s, CHS2, 1 H),
4.5-4.4 (m, CH2, 2 H), 3.55-3.45 (m, CH2, 2 H), 3.07 (m,
2×CH2, 4 H). 13C NMR (75 MHz, CDCl3): δ 150.9 (quaternary
C), 150.0 (quaternary C), 139.5 (quaternary C), 138.9 (CH),
1H NMR (200 MHz, CDCl3): δ 10.15 (s, CHO, 1 H), 10.04 (s,
3
CHO, 1 H), 8.44 (s, H6, 1 H), 8.02 (d, H3 or H4, 1 H, J HH
)
3
8 Hz), 7.95 (d, H3 or H4, 1 H, J HH ) 8 Hz). FAB-MS: m/z,
2
135.2 (d, o-CH PPh3, J PC ) 11.5 Hz), 130.7 (d, p-CH PPh3,
260 (M+, 39%).
4J PC ) 2.5 Hz), 130.5 (d, i-C PPh3, J PC ) 48 Hz), 128.2 (d,
1
Syn th esis of IAr a (7a ). HS(CH2)2SH (81 µL, 0.96 mmol),
a small crystal of p-toluenesulfonic acid, and anhydrous MgSO4
were added to a solution of 6 (125 mg, 0.48 mmol) in
1,2-dichloroethane (15 mL). The resulting suspension was
refluxed for 8.5 h and then filtered over MgSO4. The resulting
pale yellow solution was concentrated (ca. 1 mL), and cold
n-pentane (3 mL) was added, causing the precipitation of a
colorless solid, which was filtered, washed with cold n-pentane
(2 mL), and air-dried to give 7a . Yield: 140 mg, 71%. 1H NMR
m-CH PPh3, 3J PC )11 Hz), 124.5 (CH), 123.7 (CH), 65.3 (CHS2),
55.4 (CHS2), 43.7 (2xCH2), 40.0 (2×CH2). 31P NMR (121 MHz,
CDCl3, room temperature): δ 36.4 (vb s, ω1/2 ) 55 Hz, PPh3).
At -55 °C: 37.7 (s, PPh3). Anal. Calcd for C30H28ClPPdS4: C,
52.25; H, 4.09. Found: C, 51.60; H, 4.19. Single crystals were
grown by slow diffusion of Et2O into a solution of 5a * in Cl2-
CH2.
Syn th esis of [P d (K2-C,S-Ar a )I(P P h 3)] (5a ). Method A.
PPh3 (51 mg, 0.19 mmol) was added to a suspension of 10a
(100 mg, 0.10 mmol) in Cl2CH2 (20 mL). After stirring for 15
min the resulting mixture was filtered over Celite, the filtrate
was concentrated to ca. 1 mL, and Et2O (7 mL) was added,
causing the precipitation of a solid, which was filtered, washed
with Et2O (3 × 2 mL), and air-dried to give yellow 5a . Yield:
132 mg, 88%.
4
(200 MHz, CDCl3): δ 7.95 (d, H6, 1 H, J HH ) 2 Hz), 7.75 (d,
3
3
4
H3, 1 H, J HH ) 8 Hz), 7.48 (dd, H4, 1 H, J HH ) 8 Hz, J HH
)
2 Hz), 5.87 (s, CHS2, 1 H), 5.51 (s, CHS2, 1 H), 3.8-3.2 (m,
CH2, 8 H). FAB-MS: m/z, 413 (M+, 22%).
Syn th esis of IAr b (7b). It was similarly prepared from 8
(400 mg, 0.12 mmol) and HS(CH2)2SH (104 µL, 0.12 mmol)
during 18 h to give colorless 7b. Yield: 271 mg, 56%. 1H NMR
(200 MHz, CDCl3): δ 7.34 (s, C6H, 1 H), 5.99 (s, CHS2, 1 H),
3.89 (s, OMe, 3 H), 3.87 (b s, 2×OMe, 6 H), 3.6-3.3 (m, CH2,
4 H). FAB-MS: m/z, 398 (M+, 100%), 271 (M+ - I, 41%).
Syn th esis of [P d (K2-C,S-Ar a )(µ-I)]2 (10a ). The iodoarene
7a (557 mg, 1.35 mmol) was added to a solution of “Pd(dba)2”
([Pd2(dba)3]‚dba, dba ) dibenzylideneacetone) (702 mg, 1.22
mmol) in toluene (22 mL) under nitrogen. The mixture was
stirred under nitrogen for 1.5 h and the solvent removed in
vacuo. From this moment it is not necessary to work under
nitrogen. The residue was triturated with Cl2CH2 (5 mL),
filtered, washed with Cl2CH2 (5 mL) and Et2O (3 × 2 mL),
air-dried, heated in an oven at 70 °C, and treated in a
desiccator under P2O5 to give 10a as an orange solid. Yield:
527 mg, 84%. Mp: 205 °C (dec). Anal. Calcd for C24H26I2-
Pd2S4: C, 27.78; H, 2.53; S, 24.72. Found: C, 27.32; H, 2.32;
S, 24.69. This complex is not soluble enough for NMR
measurements.
Method B. The iodoarene 7a (150 mg, 0.36 mmol) was added
to a solution of “Pd(dba)2” (167 mg, 0.30 mmol) and PPh3 (95
mg, 0.36 mmol) in toluene (20 mL) under nitrogen, and the
mixture was stirred for 23 h. The solvent was removed in
vacuo. From this moment it is not necessary to work under
nitrogen. The residue was extracted with Cl2CH2 (30 mL) and
this extract filtered over Celite. The solution was concentrated
(ca. 1 mL), and addition of Et2O (8 mL) caused the precipitation
of a solid, which was filtered, washed with Et2O (3 × 2 mL),
and air-dried to give yellow 5a . Yield: 145 mg, 64%. Mp: 180
1
°C (dec). H NMR (200 MHz, CDCl3): δ 7.9-7.2 (m, PPh3, 15
3
3
H), 7.10 (d, H3, 1 H, J HH ) 8 Hz), 6.96 (dd, H4, 1 H, J HH
)
4
8 Hz, J HH ) 1.5 Hz), 6.64 (b s, H6, 1 H), 5.87 (s, CHS2, 1 H),
4.85 (s, CHS2, 1 H), 4.6-4.4 (m, CH2, 2 H), 3.6-3.4 (m, CH2,
2 H), 3.02 (s, 2×CH2, 4 H). 13C NMR (75 MHz, CDCl3): δ 156.8
(quaternary C), 149.1 (quaternary C), 138.7 (CH), 138.5
(quaternary C), 135.3 (d, o-CH PPh3, J PC ) 11.6 Hz), 131.8
(d, i-C PPh3, J PC ) 49 Hz), 130.6 (2×CH), 128.1 (d, m-CH
2
1
Syn th esis of [P d (K2-C,S-Ar b)(µ-I)]2 (10b). Complex 10b
was prepared as for 10a from 7b (250 mg, 0.63 mmol) and
“Pd(dba)2” (327 mg, 0.57 mmol) in toluene (18 mL). Reaction
time was 24 h. The residue after evaporation of the solvent
was recrystallized from Cl2CH2/Et2O, giving a solid, which was
filtered, washed with Et2O (3 × 2 mL), and air-dried to give
3
4
PPh3, J PC ) 11 Hz), 123.9 (d, p-CH PPh3, J PC ) 9 Hz), 67.1
(CHS2), 55.4 (CHS2), 44.5 (CH2), 39.8 (3×CH2). 31P NMR (121
MHz, CDCl3): δ 15.80 (PPh3). Anal. Calcd for C30H28IPPdS4:
C, 46.13; H, 3.62; S, 16.42. Found: C, 46.10; H, 3.24; S, 16.00.
Syn th esis of [P d (K2-C,S-Ar b)I(P P h 3)] (5b). Method A.
Yellow 5b was prepared as for 5a from 10b (100 mg, 0.10
mmol) and PPh3 (52 mg, 0.20 mmol). Yield: 135 mg, 89%.
Method B. As described for 5a from “Pd(dba)2” (130 mg, 0.23
mmol), 5b was prepared from PPh3 (59 mg, 0.23 mmol) and
the iodoarene 7b (100 mg, 0.25 mmol). Yield: 92 mg, 53%.
Mp: 126 °C. 1H NMR (300 MHz, CDCl3): δ 8.2-7.0 (m, PPh3,
15 H), 6.61 (s, C6H, 1 H), 5.92 (s, CHS2, 1 H), 4.4 (br m, CH2,
2 H), 3.6-3.2 (m, CH2, 2 H), 3.75 (s, MeO, 3 H), 3.40 (s, MeO,
3 H), 2.98 (s, MeO, 3 H). 13C NMR (75 MHz, CDCl3): δ 154.9
(quaternary C), 151.2 (quaternary C), 145.4 (quaternary C),
141.2 (quaternary C), 140.8 (quaternary C), 134.6 (b s, m-CH
1
orange 10b. Yield: 201 mg, 77%. Mp: 170 °C (dec). H NMR
(300 MHz, CDCl3): δ 6.58 (s, C6H, 1 H), 5.8-5.5 (m, CH2, 1
H), 5.69 (s, CHS2, 1 H), 5.3-5.1 (m, CH2, 1 H), 4.0-3.5 (m,
CH2, 2 H), 3.85 (s, MeO, 3 H), 3.68 (s, MeO, 3 H), 3.67 (s, MeO,
3 H). 13C NMR: Not soluble enough. Anal. Calcd for C24H30I2O6-
Pd2S4: C, 28.56; H, 3.00; S, 12.70. Found: C, 28.93; H, 3.01;
S, 12.67.
Syn th esis of [P d (K2-C,S-Ar b)(P P h 3)2]TfO (11b). Method
A. To a suspension of complex 10b (100 mg, 0.10 mmol) in
Cl2CH2 (7 mL) was added Tl(TfO) (70 mg, 0.20 mmol). After
30 min stirring PPh3 (104 mg, 0.40 mmol) was added and the
mixture stirred for 6 h. The yellow suspension was filtered
over Celite, giving a yellow solution, which was concentrated
(ca. 1 mL). Addition of Et2O (8 mL) caused the precipitacion
of a solid, which was filtered, washed with Et2O (2 × 3 mL),
and air-dried to give yellow 11b. Yield: 184 mg, 88%.
Method B. “Pd(dba)2” (130 mg, 0.23 mmol) and PPh3 (118
mg, 0.45 mmol) were mixed under nitrogen in toluene (20 mL)
and stirred for 5 min. Then Tl(TfO) (80 mg, 0.23 mmol) and
7b (100 mg, 0.25 mmol) were added, and the resulting
suspension was stirred for 24 h. After this time it is not
2
PPh3), 129.9 (p-CH PPh3), 127.4 (d, o-CH PPh3, J PC ) 10.5
Hz), 104.7 (CH5), 69.3 (CHS2), 60.9 (MeO), 60.2 (MeO), 56.3
(MeO), 43.9 (vb s, CH2). 31P NMR (121 MHz, CDCl3): δ 29.52
(PPh3). Anal. Calcd for C30H30IO3PPdS2: C, 46.98; H, 3.95; S,
8.36. Found: C, 46.67; H, 3.79; S, 8.12.
Syn th esis of IC6H3(CHO)2-2,5 (6). An excess of NaI was
added to a suspension of I2 (822 mg, 3.24 mmol) in water (225
mL) with continuous stirring until the dissolution of the I2.
The mercurial 1 (1.20 g, 3.25 mmol) was added, and the
mixture was stirred for 3 days with protection against light.

Ortho-Mercuriated and -Palladated Arylacetals
Organometallics, Vol. 23, No. 6, 2004 1297
necessary to work under nitrogen. The solvent was evaporated
to dryness in vacuo, leaving a residue that was extracted with
Cl2CH2 (30 mL), the extract then being filtered over Celite.
The resulting solution was concentrated (ca. 1 mL), and Et2O
(10 mL) was added, precipitating a solid, which was filtered,
washed with Et2O (2 × 3 mL), air-dried, and heated in an oven
at 70 °C for 10 min to give 11b. Yield: 152 mg, 64%. Mp: 126
h. The mixture was filtered over Celite, the filtrate was
concentrated (ca. 1 mL), and cold Et2O (7 mL) was added,
causing the precipitation of a solid, which was filtered, washed
with cold Et2O (3 × 3 mL), air-dried, and heated in an oven at
70 °C for 2 h to give 12b′ as a yellow solid. Yield: 80 mg, 69%.
Mp: 114 °C (dec). IR (cm-1): ν(CtN) 2210. 1H NMR (300 MHz,
CDCl3): δ 6.61 (s, C6H, 1 H), 5.93 (s, CHS2, 1 H), 4.4 (br m,
CH2, 2 H), 3.85 (MeO), 3.81 (MeO), 3.80 (MeO), 3.6-3.4 (m,
1
°C. ΛM ) 120 Ω-1 cm2 mol-1. H NMR (300 MHz, CDCl3): δ
5
t
7.8-7.0 (m, PPh3, 30 H), 6.68 (d, C6H, 1 H, J PH ) 3.5 Hz),
CH2, 2 H), 1.57 (s, Bu, 9 H). 13C NMR (50 MHz. CDCl3): δ
6.26 (s, CHS2, 1 H), 4.2-2.2 (br m, CH2, 4H). 3.75 (s, MeO, 3
H), 3.70 (s, MeO, 3 H), 3.09 (s, MeO, 3 H). 13C NMR (75 MHz,
CDCl3): δ 133.8 (d, o-CH PPh3, 2J PC ) 11.5 Hz), 133.6 (d, o-CH
156.3 (quaternary C), 151.8 (quaternary C), 145.1 (quaternary
C), 141.5 (quaternary C), 140.2 (quaternary C), 107.3 (qua-
ternary C), 104.8 (CH, C6H), 67.4 (CHS2), 61.6 (MeO), 60.8
2
t
PPh3, J PC ) 14 Hz), 131.2 (p-CH PPh3), 130.6 (p-CH PPh3),
(MeO), 56.1 (MeO), 44.2 (b, 2×CH2), 40.4 (quaternary C Bu),
3
128.9 (d, m-CH PPh3, J PC ) 10 Hz), 128.2 (d, m-CH PPh3,
29.8 (tBu). Anal. Calcd for C17H24INO3PdS4: C, 34.73; H, 4.12;
N, 2.38; S, 10.91. Found: C, 34.59; H, 4.07; N, 2.30; S, 10.75.
Syn th esis of [P d (K2-C,S-Im a )(µ-I)]2 (13a ). Method A. A
solution of 12a (45 mg, 0.07 mmol) in Cl2CH2 was stirred for
74 h. The resulting suspension was concentrated (ca. 1 mL)
and Et2O (6 mL) added. The suspension was filtered, and the
solid washed with Et2O (2 × 3 mL), air-dried, and heated in
an oven at 65 °C for 20 min to give 13a as a yellow solid.
Yield: 31 mg, 71%.
3J PC ) 10.5 Hz), 106.8 (CH C6H), 69.9 (CHS2), 60.9 (MeO), 60.2
(MeO), 56.2 (MeO), 42.7 (b, CH2), 37.3 (b, CH2). 31P NMR (121
2
2
MHz, CDCl3): δ 27.84 (d, J PP ) 38 Hz), 10.72 (d, J PP ) 38
Hz), cis-(PPh3)2. Anal. Calcd for C49H45F3O6P2PdS3: C, 55.96;
H, 4.32; S, 9.15. Found: C, 55.53; H, 4.10; S, 9.03.
Syn th esis of [P d (K2-C,S-Ar b)(bp y)]TfO (11b*). Method
A. Yellow 11b* was prepared as for 11b from 10b (100 mg,
0.10 mmol), bpy (2,2′-bipyridine) (31 mg, 0.20 mmol), and Tl-
(TfO) (70 mg, 0.20 mmol). Yield: 110 mg, 81%.
Method B. Complex 10a (50 mg, 0.05 mmol) was added to
a solution of 14a (see below) (75 mg, 0.10 mmol) in Cl2CH2
(10 mL). The resulting suspension was stirred for 5 days. The
suspension was concentrated (ca. 1 mL) and Et2O (6 mL) added
in order to complete the precipitation. The solid was filtered,
washed with Et2O (2 × 3 mL), air-dried, and heated in an oven
at 65 °C for 20 min to give 13a . Yield: 79 mg, 63%. Mp: 165
(dec). IR (cm-1): ν(CdN) 1632. Not soluble enough for NMR
measurements. Anal. Calcd for C21H22INPdS4: C, 38.80; H,
3.42; N, 2.16; S, 19.73. Found: C, 37.18; H, 3.29; N, 2.04; S,
20.38. The insolubility of 13a prevented further purification.
Syn th esis of [P d (K2-C,S-Im b)(µ-I)]2 (13b). Method A.
XyNC (23 mg, 0.18 mmol) was added to a solution of 10b (90
mg, 0.09 mmol) in Cl2CH2 (20 mL). The mixture was stirred
for 22 h. A yellow solid precipitated during this time. It was
filtered, washed with Cl2CH2 (2 × 3 mL), air-dried, heated in
an oven at 70 °C for 14 h, and treated in a desiccator with
P2O5 for 2 days to give 13b as a yellow solid. Yield: 89 mg,
79%.
Method B. Complex 10b (75 mg, 0.07 mmol) was added to
a solution of 14b (see below) (114 mg, 0.15 mmol) in Cl2CH2
(15 mL). The mixture was stirred for 4 h. The resulting
suspension was concentrated (ca. 1 mL) and Et2O (6 mL) added
in order to complete the precipitation. The solid was filtered,
washed with Et2O (2 × 3 mL), and air-dried to give 13b.
Yield: 152 mg, 80%. Mp: 170 (dec). IR (cm-1): ν(CdN) 1666,
1644. Not soluble enough for NMR measurements. Anal. Calcd
for C42H48I2N2O6Pd2S4: C, 39.66; H, 3.81; N, 2.20; S, 10.08.
Found: C, 39.49; H, 3.82; N, 2.29; S, 9.96.
Method B. 11b* was prepared as described for 11b from
“Pd(dba)2” (195 mg, 0.34 mmol), bpy (53 mg, 0.34 mmol), 7b
(150 mg, 0.38 mmol), and Tl(TfO) (120 mg, 0.34 mmol). Yield:
1
165 mg, 71%. Mp: 166 °C. ΛM ) 127 Ω-1 cm2 mol-1. H NMR
(300 MHz, CDCl3): δ 8.71, 8.62, 8.51-8.42, 8.26-8.16, 7.86,
7.5-7.4 (m, bpy, 8 H), 6.68 (s, C6H, 1 H), 5.97 (s, CHS2, 1 H),
4.2-3.2 (br m, CH2, 4H). 3.90 (s, MeO, 3 H), 3.87 (s, MeO, 3
H), 3.85 (s, MeO, 3 H). 13C NMR (75 MHz, CDCl3): δ 155.8
(quaternary C), 155.7 (quaternary C), 154.4 (quaternary C),
154.1 (CH bpy), 152.4 (quaternary C), 151.7 (CH bpy), 142.2
(quaternary C), 141.0 (CH bpy), 140.7 (CH bpy), 133.2 (qua-
ternary C), 128.4 (CH bpy), 126.0 (CH bpy), 123.8 (CH bpy),
123.6 (CH bpy), 123.0 (quaternary C), 105.5 (CH C6H), 68.6
(b CHS2), 63.0 (MeO), 61.1 (MeO), 56.2 (MeO), 41.7 (vb
2×CH2). Anal. Calcd for C23H23F3N2O6PdS3: C, 40.44; H, 3.40;
N, 4.10; S, 14.08. Found: C, 40.53; H, 3.27; N, 4.29; S, 14.08.
Syn th esis of [P d (K2-C,S-Ar a )I(CNXy)] (12a ). XyNC (23
mg, 0.18 mmol) was added to a suspension of 10a (100 mg,
0.10 mmol) in Cl2CH2 (20 mL). After 10 min the mixture was
filtered over Celite, the filtrate was concentrated (ca. 1 mL),
and Et2O (10 mL) was added, causing the precipitation of a
solid that was filtered, washed with Et2O (3 × 3 mL), air-dried,
and heated in an oven at 70 °C for 2 h to give 12a as a yellow
solid. Yield: 78 mg, 67%. Mp: 146 °C (dec). IR (cm-1): ν(Ct
N) 2182. 1H NMR (200 MHz, CDCl3): δ 7.63 (d, H6, 1 H, 4J HH
) 1.5 Hz), 7.35-7.0 (m, C6H3 and Xy, 5 H), 5.91 (s, CHS2, 1
H), 5.53 (s, CHS2, 1 H), 4.26 (br m, CH2, 2 H), 3.6-3.2 (m,
3×CH2, 6 H), 2.61 (s, Me, 6 H). 13C NMR: The compound
Syn th esis of [P d (K2-C,S-Im a )I(CNXy)] (14a ). XyNC (50
mg, 0.38 mmol) was added to a suspension of 10a (100 mg,
0.10 mmol) in Cl2CH2 (15 mL), and the resulting solution was
stirred for 5 h and then filtered over Celite. The filtrate was
concentrated (ca. 1 mL), Et2O (10 mL) was added, and the
resulting suspension was filtered. The solid was washed with
Et2O (2 × 3 mL), air-dried, and heated in an oven at 70 °C for
2 h to give 14a as a yellow solid. Yield: 123 mg, 82%. Mp:
decomposes during the experiment. Anal. Calcd for C21H22
-
INPdS4: C, 38.80; H, 3.42; N, 2.16; S, 19.73. Found: C, 38.40;
H, 3.36; N, 2.36; S, 19.61.
Syn th esis of [P d (K2-C,S-Ar a )I(CNtBu )] (12a ′). Yellow
12a ′ was prepared as for 12a from 10a (105 mg, 0.10 mmol)
t
and BuNC (21.5 µL, 0.19 mmol). Yield: 61 mg, 53%. Mp: 138
°C (dec). IR (cm-1): ν(CtN) 2214. 1H NMR (200 MHz,
4
CDCl3): δ 7.56 (d, H6, 1 H, J HH ) 1.8 Hz), 7.23 (dd, H4, 1 H,
4
3
3J HH ) 7.8 Hz, J HH ) 1.8 Hz), 7.05 (d, H3, 1 H, J HH ) 7.8
1
190 °C (dec). IR (cm-1): ν(CtN) 2182, ν(CdN) 1632. H NMR
Hz), 5.88 (s, CHS2, 1 H), 5.57 (s, CHS2, 1 H), 4.22 (br m, CH2,
(300 MHz, CDCl3): δ 7.79 (m, 1 H), 7.6-7.5 (m, 2 H), 7.21 (t,
2 H), 3.6-3.2 (m, 3×CH2, 6 H), 1.65 (s, Bu, 9 H). 13C NMR
t
3
p-H Xy, 1 H, J HH ) 7 Hz), 7.1-7.0 (m, 2 H), 6.88 (b s, 3 H),
(75 MHz. CDCl3): δ 153.4 (quaternary C), 151.5 (quaternary
C), 138.6 (CH), 138.2 (quaternary C), 125.4 (CH), 124.7 (CH),
65.6 (CHS2), 56.9 (CHS2), 40.1 (4×CH2), 43.8 (quaternary C
tBu), 30.1 (tBu). Anal. Calcd for C17H22INPdS4: C, 33.92; H,
3.69; N, 2.33; S, 21.30. Found: C, 33.89; H, 3.70; N, 2.64; S,
21.45.
5.69 (s, CHS2, 1 H), 5.21 (s, CHS2, 1 H), 4.0-3.2 (several br
m, CH2, 8 H), 2.30 (b s, 2×Me, 6 H), 2.20 (s, 2×Me, 6 H). 13C
NMR (75 MHz, CDCl3): δ 179.5 (CdN), 149.7 (quaternary C),
142.3 (quaternary C), 141.1 (quaternary C), 140.4 (quaternary
C), 135.2 (quaternary C), 132.5 (quaternary C), 129.7 (CH),
129.4 (CH), 128.1 (CH), 127.8 (CH), 126.9 (CH), 126.8 (qua-
ternary C), 125.7 (CH), 123.8 (CH), 55.4 (CHS2), 50.9 (CHS2),
40.1 (4×CH2), 19.2 (Me), 18.8 (Me). Anal. Calcd for C30H31IN2-
PdS4: C, 46.12; H, 4.01; N, 3.59; S, 16.42. Found: C, 46.43;
Syn th esis of [P d (K2-C,S-Ar b)I(CNtBu )] (12b′). tBuNC (22
µL, 0.20 mmol) was added to a suspension of 10b (103 mg,
0.10 mmol) in Cl2CH2 (15 mL) and the mixture stirred for 2.5

1298 Organometallics, Vol. 23, No. 6, 2004
Vicente et al.
H, 4.14; N, 3.91; S, 16.48. Single crystals were grown by slow
diffusion of n-hexane into a solution of 14a in Cl2CH2.
Syn th esis of [P d (K2-C,S-Im a ′)I(CNtBu )] (14a ′). This was
added to a suspension of 10a (100 mg, 0.10 mmol) in Cl2CH2
(20 mL). The mixture was stirred for 4 h, the resulting
suspension was filtered over Celite, and the filtrate was
concentrated (ca. 1 mL). Addition of Et2O caused the precipita-
tion of a solid, which was filtered, washed with Et2O (2 × 3
mL), air-dried, and heated in an oven at 70 °C for 2 h to give
yellow 15a . Yield: 110 mg, 72%. Mp: 140 °C (dec). ΛM ) 121
Ω-1 cm2 mol-1. IR (cm-1): ν(CtN) 2180, ν(CdN) 1632. 1H NMR
(300 MHz, CDCl3): δ 8.0-6.8 (several m, 9 H), 5.70 (s, CHS2,
1 H), 5.30 (b s, CHS2, 1 H), 4.1-3.2 (several br m, CH2, 8 H),
2.30 (s, 2×Me, 6 H), 2.21 (s, 2×Me, 6 H). 13C NMR (75 MHz,
CDCl3): δ 149.0 (quaternary C), 142.6 (quaternary C), 139.6
(quaternary C), 135.2 (quaternary C), 132.3 (quaternary C),
130.2 (CH), 129.6 (CH), 128.2 (CH), 128.0 (CH), 127.5 (CH),
127.0 (quaternary C), 126.0 (CH), 125.1 (quaternary C), 124.2
(CH), 122.9 (quaternary C), 118.6 (quaternary C), 55.3 (CHS2),
51.7 (b sCHS2), 40.1 (4×CH2), 19.3 (Me), 18.6 (Me). Anal. Calcd
for C61H62F3IN4O3Pd2S9: C, 46.23; H, 3.95; N, 3.54; S, 18.21.
Found: C, 46.56; H, 4.12; N, 3.58; S, 18.69.
t
prepared as for 14a from 10a (100 mg, 0.10 mmol) and BuNC
(43 µL, 0.38 mmol). The product was recrystallized from Cl2-
CH2/Et2O and heated in an oven at 70 °C for 1 h to give 14a ′
as a yellow solid. Yield: 88 mg, 67%. Mp: 156 °C (dec). IR
(cm-1): ν(CtN) 2196, ν(CdN) 1666. 1H NMR (200 MHz,
3
CDCl3): δ 7.80 (d, H3 or H4, 1 H, J HH ) 8 Hz), 7.40 (d, H4 or
3
H3, 1 H, J HH ) 8 Hz), 7.06 (s, H6, 1 H), 5.61 (s, CHS2, 1 H),
4.06 (s, CHS2, 1 H), 4.2-3.9 (m, CH2, 1 H), 3.9-3.6 (m, CH2,
t
t
1 H), 3.6-3.2 (m, 3×CH2, 6 H), 1.63 (s, Bu, 9 H), 1.54 (s, Bu,
9 H). 13C NMR (75 MHz, CDCl3): δ 170.2 (CdN), 140.9
(quaternary C), 134.1 (quaternary C), 130.5 (quaternary C),
t
127.8 (CH), 125.5 (CH), 122.0 (CH), 58.1 (quaternary C Bu),
55.8 (CHS2), 51.5 (CHS2), 45.3 (CH2), 40.1 (2×CH2), 35.1 (CH2),
31.4 (tBu), 29.9 (tBu). Anal. Calcd for C22H31IN2PdS4: C, 38.57;
H, 4.57; N, 4.09; S, 18.72. Found: C, 38.79; H, 4.66; N, 4.17;
S, 18.47.
Syn th esis of [P d (K2-C,S-Im b)I(CNXy)] (14b). XyNC (78
mg, 0.59 mmol) was added to a solution of 10b (150 mg, 0.15
mmol) in Cl2CH2 (15 mL). The resulting solution was stirred
for 4.5 h and concentrated to ca. 1 mL, Et2O (10 mL) was
added, and the resulting suspension was cooled in an ice bath.
The cold suspension was filtered and the solid washed with
Et2O (2 × 3 mL), air-dried, heated in an oven at 70 °C for 8 h,
and treated in a desiccator with P2O5 for 3 days to give 14b
as a yellow solid. Yield: 194 mg, 85%. Mp: 182 °C (dec). IR
(cm-1): ν(CtN) 2170, ν(CdN) 1660. 1H NMR (200 MHz,
CDCl3): δ 7.4-6.7 (several m, 7 H), 5.17 (s, CHS2, 1 H), 4.3-
4.1 (br m, CH2, 1 H), 4.1-3.9 (br m, CH2, 1 H), 4.02 (s, MeO,
3 H), 3.96 (s, MeO, 3 H), 3.95 (s, MeO, 3 H), 3.6-3.2 (m, CH2,
2 H), 2.26 (s, 4×Me, 12 H). At -60 °C: 7.38 (s, 1 H), 7.34-
7.24 (m, 2 H), 7.22-7.08 (m, 2 H), 6.98 (t, 1 H, 3J HH ) 7.5 Hz),
Syn th esis of [P d {(K2-C,S-Im b)(CNXy)}2(µ-I)]TfO (15b).
Tl(TfO) (35 mg, 0.10 mmol) was added to a suspension of 10b
(100 mg, 0.10 mmol) in Cl2CH2 (20 mL), and the mixture was
stirred for 15 min. XyNC (52 mg, 0.40 mmol) was added, and
stirring was continued for
a further 1 h. The resulting
suspension was filtered, the filtrate was concentrated (ca. 1
mL), and Et2O (10 mL) was added to complete the precipitation
of a solid, which was filtered, washed with Et2O (2 × 3 mL),
air-dried, and treated in a desiccator with P2O5 for 3 days to
give 15b as a yellow solid. Yield: 101 mg, 66%. Mp: 156 °C
(dec). IR (cm-1): ν(CtN) 2176, ν(CdN) 1682. 1H NMR (300
MHz, CDCl3): δ 7.5-6.8 (several multiplets, C6H + C6H3Me2),
5.21 (s, CHS2, 1 H), 4.01 (s, MeO, 3 H), 3.98 (s, MeO, 3 H),
3.97 (s, MeO, 3 H), 3.5-3.2 (m, CH2, 4 H), 2.26 (s, 4×Me, 12
H). 13C NMR: Decomposes during the experiment. Anal. Calcd
for C61H66F3IN4O9Pd2S5: C, 47.07; H, 4.28; N, 3.60; S, 10.30.
Found: C, 46.88; H, 4.20; N, 3.60; S, 10.28.
Syn th esis of [P d II(K2-C,S-Ar c)(P P h 3)2]TfO T [P d 0{η2-
C,S-S(To)dCHC6H(STo)-2-(OMe)3-3,4,5}(P P h 3)2]TfO (17).
Method A. “Pd(dba)2” (140 mg, 0.24 mmol), PPh3 (128 mg, 0.49
mmol), Tl(TfO) (86 mg, 0.24 mmol), and 9 (150 mg, 0.27 mmol)
were were mixed in toluene (25 mL) under nitrogen and stirred
for 26 h under nitrogen. After this time it is not necessary to
work under nitrogen. The solvent was evaporated to dryness,
and the residue was extracted with Cl2CH2 (30 mL) and
filtered over Celite. The filtrate was concentrated (ca. 1 mL),
Et2O (5 mL) was added, and the suspension was filtered. The
solid was washed with Et2O (2 × 3 mL) and air-dried, affording
orange 17. Yield: 112 mg, 39%.
3
6.73 (d, 1 H, J HH ) 7.5 Hz), 5.18 (s, CHS2, 1 H), 4.3-4.2 (m,
CH2, 1 H), 4.02 (s, MeO, 3 H), 3.99 (s, 2×MeO, 6 H), 3.5-3.4
(m, CH2, 2 H), 3.3-3.2 (m, CH2, 1 H), 2.43 (s, Me, Xy, 3 H),
2.26 (s, 2×Me, Xy, 6 H), 2.08 (s, Me Xy, 3 H). 13C NMR (50
MHz, CDCl3): δ 178.0 (CdN), 151.7 (quaternary C), 150.1
(quaternary C), 148.5 (quaternary C), 142.1 (quaternary C),
135.4 (quaternary C), 130.1 (quaternary C), 129.6 (CH), 128.2
(quaternary C), 127.9 (CH), 126.2 (quaternary C), 123.7 (CH),
108.9 (CH, C6H), 61.2 (MeO or CHS2), 60.8 (MeO or CHS2),
56.4 (MeO or CHS2), 50.6 (MeO or CHS2), 43.0 (CH2), 34.2
(CH2), 19.0 (Me), 18.6 (Me). Anal. Calcd for C30H33IN2O3PdS2:
C, 46.97; H, 4.35; N, 3.65; S, 8.36. Found: C, 47.04; H, 4.40;
N, 3.92; S, 7.95. Single crystals were grown by slow diffusion
of n-hexane into a solution of 14b in Cl2CH2.
Syn th esis of [P d (K2-C,S-Im b′)I(CNtBu )] (14b′). tBuNC (67
µL, 0.59 mmol) was added to a solution of 10b (150 mg, 0.15
mmol) in Cl2CH2 (25 mL). The resulting solution was stirred
for 1.5 h and the solvent evaporated to dryness. The residue
was triturated with Et2O (5 mL), the suspension filtered, and
the solid washed with Et2O (2 × 3 mL), air-dried, heated in
an oven at 70°C for 2 h, and treated in a desiccator with P2O5
for 4 days to give 14b′ as a yellow solid. Yield: 157 mg, 79%.
Method B. Complex 16 (100 mg, 0.08 mmol), Tl(OTf) (54
mg, 0.15 mmol), and PPh3 (80 mg, 0.30 mmol) were mixed in
Cl2CH2 (7 mL) and stirred for 6 h. The resulting mixture was
filtered over Celite, the solution was concentrated (ca. 1 mL),
and Et2O (5 mL) was added. The suspension was filtered, and
the solid was washed with Et2O and air-dried to give 17 as an
orange solid. Yield: 179 mg, 98%. Mp: 127 °C. ΛM ) 130 Ω-1
cm2 mol-1
.
1H NMR (300 MHz, CDCl3, TMS): δ 7.5-6.2
1
Mp: 142 °C (dec). IR (cm-1): ν(CtN) 2198, ν(CdN) 1664. H
3
(several m, 39 H); 5.32 (apparent t, J PH ) 6.3 Hz, CHPd, 1
H); 3.87 (s, MeO, 3 H), 3.76 (s, MeO, 3 H), 3.59 (s, MeO, 3 H),
2.44, (s, Me To, 3 H), 2.31 (s, Me To, 3 H). 13C NMR (50 MHz,
CDCl3): δ 155.2 (quaternary C), 155.0 (quaternary C), 142.8
(quaternary C), 140.5 (quaternary C), 133.8 (CH), 133.6 (CH),
133.1 (CH), 132.9 (CH), 132.4 (quaternary C), 132.1 (quater-
nary C), 131.3 (quaternary C), 131.0 (quaternary C), 130.7
(CH), 130.5 (CH), 130.2 (quaternary C), 130.0 (CH), 129.7 (CH);
128.7 (CH), 128.5 (CH), 128.3 (CH), 126.8 (CH), 109.2 (CH,
C6H), 78.4 (dd, CHPd, 2J PC ) 56 Hz, 2J PC ) 5 Hz), 60.8 (MeO),
60.6 (MeO), 56.3 (MeO), 21.1 (Me To), 20.8 (Me To). 31P{1H}
NMR (300 MHz, CDCl3): δ 7.26 (s, C6H, 1 H), 4.93 (s, CHS2,
1 H), 4.1-3.95 (m, CH2, 1 H), 3.91 (s, MeO, 3 H), 3.88 (s, MeO,
3 H), 3.85 (s, MeO, 3 H), 3.8-3.65 (m, CH2, 1 H), 3.35-3.25
t
t
(m, CH2, 2 H), 1.62 (s, Bu, 9 H), 1.51 (s, Bu, 9 H). 13C NMR
(75 MHz, CDCl3): δ 167.0 (quaternary C), 150.9 (quaternary
C), 146.9 (quaternary C), 142.6 (quaternary C), 130.0 (qua-
ternary C), 129.1 (CH), 128.2 (quaternary C), 108.5 (CH, C6H),
61.6 (MeO or CHS2), 60.7 (MeO or CHS2), 58.0 (quaternary C
t
tBu), 57.5 (quaternary C Bu), 56.4 (MeO or CHS2), 51.3 (MeO
or CHS2), 44.7 (CH2), 35.2 (CH2), 31.2 (tBu), 29.7 (tBu). Anal.
Calcd for C22H33IN2O3PdS2: C, 39.38; H, 4.97; N, 4.18; S, 9.56.
Found: C, 39.50; H, 5.20; N, 4.19; S, 9.39.
2
NMR (121 MHz, CDCl3): δ 27.13 (d, J PP) ) 37.3 Hz); 20.38
2
Syn th esis of [P d {(K2-C,S-Im a )(CNXy)}2(µ-I)]TfO (15a ).
Tl(TfO) (35 mg, 0.10 mmol) and XyNC (50 mg, 0.38 mmol) were
(d, J PP ) 37.3 Hz). Anal. Calcd for C61H55F3O6P2PdS3: C,
60.76; H, 4.61; S, 7.98. Found: C, 60.98; H, 4.71; S, 7.92.

Ortho-Mercuriated and -Palladated Arylacetals
Organometallics, Vol. 23, No. 6, 2004 1299
Syn th esis of [P d (K2-C,S-Ar c)I(CNXy)] (18). XyNC (50 mg,
0.38 mmol) was added to a solution of 16 (250 mg, 0.19 mmol)
in Cl2CH2 (10 mL). The resulting solution was stirred for 10
min and the solvent evaporated to dryness. The residue was
triturated with Et2O (10 mL), filtered, washed with Et2O (2 ×
3 mL), and air-dried to give yellow 18. Yield: 255 mg, 85%.
Mp: 140 °C. IR (cm-1): ν(CtN) 2178. 1H NMR (200 MHz,
treated in a desiccator with P2O5 for 3 days to give 19′ as a
yellow solid. Yield: 96 mg, 77%. Mp: 120 °C (dec). IR (cm-1):
1
ν(CtN) 2202. H NMR (300 MHz, CDCl3): δ 7.3-6.8 (br m, 9
H), 5.66 (vb s, CHPd, 1 H), 3.80 (s, MeO, 3 H), 3.75 (b s, MeO,
3 H), 3.64 (s, MeO, 3 H), 2.29 (s, Me To, 3 H), 2.20 (s, Me To,
3 H), 1.44 (s, tBu, 9 H). At -60 °C: 7.47 (s, C6H, 1 H), 7.2-6.8
(m, 8 H), 5.87 (s, CHPd, 1 H), 3.87 (s, MeO, 3 H), 3.84 (s, MeO,
3 H), 3.61 (s, MeO, 3 H), 2.31 (s, Me To, 3 H), 2.28 (s, Me To,
3
3
CDCl3): δ 7.58 (d, 2 H, J HH ) 8 Hz), 7.38 (d, 2 H, J HH ) 7.6
Hz), 7.3-6.8 (m, 7 H), 6.40 (s, C6H, 1 H), 5.49 (s, CH-Pd, 1
H), 3.79 (s, MeO, 3 H), 3.66 (s, MeO, 3 H), 3.60 (s, MeO, 3 H),
2.48 (s, 2×Me Xy, 6 H), 2.32 (s, Me To, 3 H), 2.13 (s, Me To, 3
H). 13C NMR (50 MHz, CDCl3): δ 155.7 (quaternary C), 152.3
(quaternary C), 148.7 (quaternary C), 143.8 (quaternary C),
141.4 (quaternary C), 139.1 (quaternary C), 138.0 (quaternary
C), 135.8 (quaternary C), 134.1 (CH), 132.9 (quaternary C),
130.3 (CH), 130.0 (quaternary C), 129.7 (CH), 129.6 (CH), 129.5
(CH), 128.1 (quaternary C), 127.9 (CH), 119.9 (quaternary C),
106.8 (CH, C6H), 60.8 (MeO), 60.7 (MeO), 55.7 (MeO) (the
signal corresponding to CHPd could be coincident with one of
the last three signals), 21.2 (Me, To), 20.9 (Me, To), 19.0
(2×Me, Xy). Anal. Calcd for C33H34INO3PdS2: C, 50.16; H, 4.35;
N, 1.77; S, 8.12. Found: C, 50.21; H, 4.36; N, 1.80; S, 8.49.
t
3 H), 1.47 (s, Bu, 18 H). 13C NMR (50 MHz, CdCl3): δ 154.7
(quaternary C), 154.4 (quaternary C), 148.6 (quaternary C),
140.1 (quaternary C), 136.0 (quaternary C), 135.0 (quaternary
C), 134.3 (quaternary C), 129.5 (CH), 129.1 (CH), 128.5 (CH),
127.1 (CH), 115.7 (quaternary C), 106.9 (CH, C6H), 61.0 (MeO),
t
60.6 (MeO), 57.5 (quaternary C Bu), 55.9 (MeO), 29.7 (tBu),
20.9 (2×C6H4-Me-4). Anal. Calcd for C34H43IN2O3PdS2: C,
49.48; H, 5.26; N, 3.40; S, 7.77. Found: C, 49.55; H, 5.44; N,
3.51; S, 7.72.
Syn th esis of [P d (K2-C,S-Ar c)I(P P h 3)] (20). Method A.
“Pd(dba)2” (78 mg, 0.14 mmol) was added under nitrogen to a
solution of 9 (94 mg, 0.17 mmol) and PPh3 (45 mg, 0.17 mmol)
in toluene (15 mL) and stirred for 15 h under nitrogen. After
this time it is not necessary to work under nitrogen. The
solvent was evaporated to dryness, the residue was extracted
with Cl2CH2 (20 mL) and filtered over Celite, and the solvent
was evaporated to dryness. The residue was triturated with
Et2O (15 mL) in an ice bath for 2 h, the suspension was filtered,
and the solid was washed with Et2O (2 × 3 mL) and air-dried,
affording yellow 20. Yield: 28 mg, 22%.
Method B. PPh3 (40 mg, 0.15 mmol) was added to a solution
of 16 (100 mg, 0.08 mmol), and the solution was stirred for 20
min. The solution was concentrated (ca. 1 mL), n-hexane (10
mL) was added, and the suspension was filtered. The solid was
washed with n-hexane (2 × 3 mL) and air-dried to give yellow
20. Yield: 97 mg, 69%. Mp: 158 °C. 1H NMR (300 MHz,
CDCl3): δ 8.0-6.8 (several m, 25 H), 3.77 (s, MeO, 3 H), 3.63
(s, MeO, 3 H), 3.51 (b s, MeO, 3 H), 2.31 (s, Me To, 3 H), 2.26
(s, Me To, 3 H). 31P NMR (121 MHz, CDCl3): δ 32.5 (s, PPh3).
Anal. Calcd for C42H40IO3PPdS2: C, 54.76; H, 4.39; S, 6.96.
Found: C, 54.98; H, 4.36; S, 6.57.
X-r a y Str u ctu r e Deter m in a tion s. Data were recorded
using Mo KR radiation (λ ) 0.71073Å), a graphite monochro-
mator, and ω and φ scans on a Bruker SMART 1000 CCD (14a
and 14b) or ω scans on a Siemens P4 diffractometer (4 and
5a *). Absorption corrections were applied on the basis of
multiple scans (program SADABS; 14b), indexed faces (14a ),
or psi-scans (4 and 5a *). Structures were refined anisotropi-
cally using the program SHELXL-97 (G. M. Sheldrick, Uni-
versity of Go¨ttingen). Hydrogen atoms were included using
rigid methyl groups or a riding model. Special features: 14a
crystallizes with one well-ordered molecule of dichloromethane.
t
Syn th esis of [P d (K2-C,S-Ar c)I(CNtBu )] (18′). BuNC (26
µL, 0.29 mmol) was added to a solution of 16 (150 mg, 0.11
mmol) in Cl2CH2 (5 mL). The solution was stirred for 1 h and
the solvent evaporated to dryness. The residue was triturated
with n-hexane (4 mL), the suspension was filtered, and the
solid was washed with n-hexane (2 × 3 mL), air-dried, heated
in an oven at 70 °C for 2 h, and treated in a desiccator with
P2O5 for 4 days to give 18′ as a yellow solid. Yield: 125 mg,
74%. Mp: 122 °C. IR (cm-1): ν(CtN) 2198. 1H NMR (300 MHz,
CDCl3): δ 7.53 (d, C6H4Me-4, 2 H, 3J HH ) 8 Hz), 7.36 (d, C6H4-
3
3
Me-4, 2 H, J HH ) 8 Hz), 7.12 (d, C6H4Me-4, 2 H, J HH ) 8
3
Hz), 7.09 (d, C6H4Me-4, 2 H, J HH ) 8 Hz), 6.32 (s, C6H, 1 H),
5.31 (s, CHPd, 1 H), 3.77 (s, MeO, 3 H), 3.61 (s, MeO, 3 H),
3.58 (s, MeO, 3 H), 2.32 (s, Me To, 3 H), 2.30 (s, Me To, 3 H),
1.49 (s, tBu, 9 H). 13C NMR (75 MHz, CdCl3): δ 155.7
(quaternary C), 152.2 (quaternary C), 149.3 (quaternary C),
141.2 (quaternary C), 139.0 (quaternary C), 137.5 (quaternary
C), 133.6 (CH), 133.3 (quaternary C), 131.3 (quaternary C),
130.3 (CH), 129.6 (CH), 129.5 (CH), 119.7 (quaternary C), 106.5
t
(CH, C6H), 60.8 (MeO), 60.7 (MeO), 57.9 (quaternary C Bu),
55.6 (MeO), 54.0 (CHPd), 29.9 (tBu), 21.1 (C6H4-Me-4), 21.0
(C6H4-Me-4). Anal. Calcd for C29H34INO3PdS2: C, 46.94; H,
4.63; N, 1.89; S, 8.64. Found: C, 46.83; H, 4.60; N, 2.11; S,
8.57.
Syn th esis of tr a n s-[P d (K2-C,S-Ar c)I(CNXy)2] (19). XyNC
(40 mg, 0.30 mmol) was added to a solution of 16 (100 mg,
0.08 mmol) in Cl2CH2 (10 mL). The resulting solution was
stirred for 7 h and the solvent evaporated to dryness. The
residue was triturated with Et2O (5 mL) at 0 °C, filtered,
washed with Et2O (2 × 3 mL), air-dried, and treated in a
desiccator with P2O5 for 16 h to give 19 as a yellow solid.
Resu lts a n d Discu ssion
1
Yield: 85 mg, 61%. Mp: 119 °C. IR (cm-1): ν(CtN) 2172. H
Syn th esis of Aceta l- a n d Dith ioa ceta l-a r ylp a lla -
d iu m Com p lexes. All attempts to prepare complexes
with the groups Ara or Arb, or 2,5-bis(p-tolyldithio-
acetal)aryl-palladium complexes, by palladation of the
corresponding dithioacetals with palladium acetate (in
toluene or acetonitrile) or by reacting the corresponding
2-formylaryl-palladium complexes23,25 with the dithiols,
were unsuccessful. The resulting mixture of compounds
had ToS (To ) p-tolyl) as the only ligand. Similar
mixtures were obtained by reacting [Pd(AcO)2] with
ToSH in acetonitrile. However, the desired complexes
were obtained using the mercurial [Hg{C6H3(CHO)2-
2,5}Cl] (1), previously synthesized by mercuration of
terephthaldehyde.25 This compound was converted into
a diacetal, which in turn was transformed into a
dithioacetal and then transmetalated to palladium, or
NMR (200 MHz, CDCl3): δ 7.4-6.7 (several m, 15 H), 5.95 (b
s, CH-Pd, 1 H), 3.74 (s, MeO, 3 H), 3.67 (s, MeO, 3 H), 3.45
(s, MeO, 3 H), 2.38 (s, Me Xy, 12 H), 2.22 (s, Me To, 3 H), 2.20
1
(s, Me To, 3 H). H NMR (200 MHz, CDCl3, -60 °C): δ 7.44
3
(s, C6H, 1 H), 7.29 (m, 2 H), 7.13 (d, 4 H, J HH ) 7.8 Hz), 6.97
3
3
(m, 4 H), 6.84 (d, 2 H, J HH ) 8.1 Hz), 6.75 (d, 2 H, J HH ) 8.1
Hz), 6.10 (s, CH-Pd, 1 H), 3.78 (s, MeO, 3 H), 3.69 (s, MeO, 3
H), 3.35 (s, MeO, 3 H), 2.39 (s, Me Xy, 12 H), 2.27 (s, Me To,
3 H), 2.22 (s, Me To, 3 H). Anal. Calcd for C42H43IN2O3PdS2:
C, 54.75; H, 4.71; N, 3.04; S, 6.96. Found: C, 54.50; H, 4.93;
N, 3.16; S, 6.64.
Syn th esis of tr a n s-[P d(K2-C,S-Ar c)I(CNtBu )2] (19′). tBuNC
(34.5 µL, 0.30 mmol) was added to a solution of 16 (100 mg,
0.08 mmol) in Cl2CH2 (10 mL). The resulting solution was
stirred for 1.5 h and concentrated (ca. 1 mL). n-Hexane (5 mL)
was added, causing the precipitation of a solid, which was
filtered, washed with n-hexane (2 × 3 mL), air-dried, and

1300 Organometallics, Vol. 23, No. 6, 2004
Vicente et al.
Sch em e 1
Sch em e 2
complexes are those that we recently prepared by
reacting the iododithioacetal IC6H(OMe)3-2,3,4-CH-
(STo)2-6 (see below) with Pd(dba)2.41
transformed into IC6H3(CHO)2-2,5 and this in turn into
IAra (Ara ) C6H3{CH(SCH2CH2S)}2-2,5), which was
used in oxidative addition reactions. Similarly, IC6H-
Despite the above successful experiences, other at-
tempts to prepare dithioacetal-aryl palladium complexes
using mercurials were fruitless. Thus, 3a did not react
with (Me4N)2[Pd2Cl6] or [PdCl2(NCMe)2] designed to
prepare complexes similar to 5a * but with ligands easy
to replace. These unsuccessful attempts prompted us
to study oxidative addition reactions to prepare halo-
(dithioacetal)arylpalladium complexes.
Oxidative Addition Reaction s. Syn th esis of 2-(1,3-
Dith iola n -2-yl)a r ylp a lla d iu m Com p lexes. We have
used this method of synthesis starting from iododithio-
acetal arenes. By reacting the mercurial 1 with I2/I-,
the iodoarene IC6H3(CHO)2-2,5 (6) was obtained (Scheme
2). This is a well-known synthesis of iodoarenes.52 By
reacting 6 with HS(CH2)2SH, the desired IAra (7a ) was
obtained. Similarly, from IC6H(OMe)3-2,3,4-CHO-6 (8)48
other iododithioacetal arenes such as IC6H(OMe)3-2,3,4-
{CH(SCH2CH2S)}-6 (7b ) or IC6H(OMe)3-2,3,4-{CH-
(STo)2}-6 (9)41 were prepared.
(OMe)3-2,3,4-(CHO)-6 was converted into IArb (Arb
)
C6H(OMe)3-2,3,4-{CH(SCH2CH2S}-6) and used in oxi-
dative addition reactions.
Tr a n sm eta la tion Rea ction s. We have reported the
synthesis of [Hg{C6H3(CHO)2-2,5}Cl] (1) by reacting
terephthaldehyde with HgO in a 1:1 volume mixture of
water and triflic acid at 95 °C.25 This mercurial reacts
with CH(OMe)3 and 96% sulfuric acid in anhydrous
methanol to give the new arylmercury compound [Hg-
{C6H3{CH(OMe)2}2-2,5}Cl] (2), which reacts with HS-
(CH2)2SH and p-toluenesulfonic acid to give [Hg(Ara)Cl]
[Ara ) C6H3{CH(SCH2CH2S)}2-2,5 (3a )] (Scheme 1).
These mercurials can be used as transmetallating
agents to prepare new organopalladium complexes
following a procedure that we have developed for the
preparation of 2,5-diformylphenylpalladium complexes
from 1.25 Thus, 2 reacts with (NMe4)2[Pd2Cl6] in the
presence of (Me4N)Cl in acetone to give the insoluble
Me4N[HgCl3]. Addition of 2,2′-bipyridine (bpy) to the
filtrate gave the neutral complex [Pd{C6H3{CH(OMe)2}2-
2,5}Cl(bpy)] (4). The reaction of 3a with trans-[PdCl2-
(PPh3)2] in the presence of (Me4N)Cl gives (NMe4)-
[HgCl3] and the aryl-palladium complex [Pd{κ-C,S-
Ara}Cl(PPh3)2] (5a *). This reaction also involves the
replacement of 1 equiv of PPh3 associated with the
chelating effect of the C,S-ligand. We propose the PPh3
to be cis to the aryl ligand because the aryl/phosphine
transphobia is greater than the aryl/chloro transphobia.
This term, which we have defined,29,38,42,49 has been
fruitfully used by other authors.19,50
The oxidative addition reaction of the iodoarenes 7a
and 7b to “Pd(dba)2” ([Pd2(dba)3]‚dba) resulted in the
formation of the ortho-palladated complexes [Pd(κ2-C,S-
(50) Albert, J .; Cadena, J . M.; Granell, J . R.; Solans, X.; Font Bardia,
M. Tetrahedron: Asymmetry 2000, 11, 1943. Albert, J .; Bosque, R.;
Cadena, J . M.; Delgado, S.; Granell, J . J . Organomet. Chem. 2001, 634,
83. Amatore, C.; Bahsoun, A. A.; J utand, A.; Meyer, G.; Ntepe, A. N.;
Ricard, L. J . Am. Chem. Soc. 2003, 125, 4212. Carbayo, A.; Cuevas, J .
Y.; Garcia Herbosa, G.; Garcia Granda, S.; Miguel, D. Eur. J . Inorg.
Chem. 2001, 2361. Carbayo, A.; Cuevas, J . V.; Garcia Herbosa, G. J .
Organomet. Chem. 2002, 658, 15. Fernandez, S.; Navarro, R.; Urrio-
labeitia, E. P. J . Organomet. Chem. 2000, 602, 151. Fernandez, A.;
Vazquez Garcia, D.; Fernandez, J . J .; Lopez Torres, M.; Suarez, A.;
Castro J uiz, S.; Vila, J . M. Eur. J . Inorg. Chem. 2002, 2389. Fernandez-
Rivas, C.; Cardenas, D. J .; Martin-Matute, B.; Monge, A.; Gutierrez-
Puebla, E.; Echavarren, A. M. Organometallics 2001, 20, 2998. J alil,
M. A.; Fujinami, S.; Nishikawa, H. J . Chem. Soc., Dalton Trans. 2001,
1091. Larraz, C.; Navarro, R.; Urriolabeitia, E. P. New J . Chem. 2000,
24, 623. Lohner, P.; Pfeffer, M.; Fischer, J . J . Organomet. Chem. 2000,
607, 12. Marshall, W. J .; Grushin, V. V. Organometallics 2003, 22,
555.
Complexes 2 and 4 are the first mercury and pal-
ladium complexes having acetal-substituted aryl ligands.
We are aware of only one such complex, [Cr{C6H4CH-
(OCH2CH2O)-2}3], reported without experimental de-
tails and characterized through an X-ray diffraction
study.51 The only reported dithioacetal aryl metal
(51) Daly, J . J .; Sanz, F.; Sneeden, R. P. A.; Zeiss, H. H. Helv. Chim.
Acta 1974, 57, 1863.
(52) Larock, R. C. In Organomercury Compounds in Organic Syn-
thesis; Hafner, K., Rees, C. W., Trost, B. M., Eds.; Reactivity and
Structure Concepts in Organic Chemistry, Vol. 22; Springer-Verlag:
Berlin, 1985.
(49) Vicente, J .; Arcas, A.; Bautista, D.; J ones, P. G. Organometallics
1997, 16, 2127.

Ortho-Mercuriated and -Palladated Arylacetals
Organometallics, Vol. 23, No. 6, 2004 1301
Sch em e 3
Sch em e 4
Ar)(µ-I)]2 [Ar ) Ara (10a ), Arb (10b)] (Scheme 3).
Although we were not able to grow single crystals in
order to determine their X-ray crystal structures, we
believe it reasonable to formulate them as dimers with
bridging iodine atoms. These complexes react with PPh3
to give complexes [Pd(κ2-C,S-Ar)I(PPh3)] [Ar ) Ara (5a ),
Arb (5b)], which can also be prepared by reaction of 7a
or 7b with “Pd(dba)2” in the presence of PPh3. The
reaction of 10b with 2 equiv of PPh3 in the presence of
Tl(TfO) resulted in the precipitation of TlI and the
formation of the cationic complexes [Pd(κ2-C,S-Arb)-
(PPh3)2]TfO (11b). In a similar reaction, 10b was
reacted with bpy and Tl(TfO), forming [Pd(κ2-C,S-Arb)-
(bpy)]TfO (11b*). Complexes 11 can also be prepared
from “Pd(dba)2” and the corresponding iodoarenes and
ligands in the presence of Tl(TfO). As in the case of 5a *,
only one isomer of 5a ,b was obtained because of the
great aryl/PR3 transphobia (see above).29,38,49
ing species analogous to complexes 12a could not be
isolated. Compound 12a evolves spontaneously in solu-
tion to the corresponding insertion product 13a , a very
insoluble material that could not be characterized by
NMR spectroscopy and that gave poor elemental analy-
ses for C and S. Its proposed structure is based on the
observation of the ν(CdN) band at 1632 cm-1 and the
disappearance of ν(CtN) at 2182 cm-1 and on its
reaction with XyNC to give 14 (see below). This type of
conversion of a coordinated into an inserted isonitrile
has been reported previously, although it requires some
thermal treatment.6,53
The reactions of complexes 10 with the isonitriles in
a 1:4 molar ratio gave compounds [Pd(κ2-C,S-Im)I(CNR)]
[Im ) C(dNR)C6H3{CH(SCH2CH2S)}2-2,5, R ) Xy, Im
The iodoarenes 7a and 7b, which lead to 4-11,
behave differently from 9 because the latter reacts with
“Pd(dba)2” to give, in most cases, a rearrangement
involving the cleavage of alkyl-S and aryl-Pd bonds
and formation of aryl-S and alkyl-Pd bonds (Chart
1).41
t
) Ima (14a ), R ) Bu, Im ) Ima′ (14a ′); Im ) C(dNR)-
C6H(OMe)3-2,3,4-(SCH2CH2S)-6, R ) Xy, Im ) Imb
t
(14b), R ) Bu, Im ) Imb′ (14b′)]. Complex 14a or 14b
was also accessible by reaction of 13a or 13b with XyNC
(1:2 molar ratio), respectively. Additionally, complex 14a
or 14b reacted with 10a or 10b to give 13a or 13b,
respectively (Scheme 4). The above results suggest that
the first step in the reaction of complexes 10 toward
isocyanides (1:2 molar ratio) involves coordination to
We have studied the reactions of 10a and 10b with
the isonitriles XyNC (Xy ) 2,6-dimethylphenyl) and
tBuNC. The 1:2 reactions starting from 10a gave the
products of bridge splitting, [Pd(κ2-C,S-Ar)I(CNR)] [Ar
t
) Ara, R ) Xy ) 2,6-dimethylphenyl (12a ), Bu (12a ′)]
t
(Scheme 4). Similarly, 10b reacts with BuNC to give
12b′ [Ar ) Arb, R ) tBu], while with XyNC it gives the
iminoacyl complex [Pd(κ2-C,S-Imb)(µ-I)]2 [Imb ) C(dNXy)-
C6H(OMe)3-2,3,4-(SCH2CH2S)-6 (13b)]; the correspond-
(53) Yamamoto, Y.; Yamazaki, H. Inorg. Chim. Acta 1980, 41, 229.
Uso´n, R.; Fornie´s, J .; Espinet, P.; Lalinde, E.; J ones, P. G.; Sheldrick,
G. M. J . Chem. Soc., Dalton Trans. 1982, 2389.

1302 Organometallics, Vol. 23, No. 6, 2004
Vicente et al.
Sch em e 5
Sch em e 6
give, after bridge-splitting, monomers 12; the second
stage involves an insertion process to give the more
thermodynamically stable dinuclear iminoacyl com-
plexes 13; finally, in excess of isocyanide, a bridge-
splitting from 13 leads to complexes 14. The reactions
of 14a ,b with complexes 10a ,b to give 13a ,b suggest
that complexes 14a ,b dissociate XyNC (to give 13a ,b),
which would also react with 10 to give 13a ,b. This
proposal is supported by NMR data (see below).
Complex 10a or 10b reacted with XyNC and Tl(TfO)
(1:4:2) to give a precipitate of TlI and a solution from
which the dimeric cation [Pd{(κ2-C,S-Im)(CNXy)}2(µ-I)]-
TfO [Im ) Ima (15a ), Imb (15b)] can be isolated instead
of the expected [Pd(µ-κ3-C,S,N-Im)(CNXy)]2(TfO)2
(Scheme 4). These reactions probably occur via the
corresponding complexes 14; it is remarkable that the
iodide ligand was not fully removed despite using the
appropriate amount of Tl(TfO). However, it was not
totally unexpected because we have found the same
behavior previously.30 Complexes 15 were also obtained
when the required 1:4:1 molar ratio was used. For
complexes 15a and 15b we propose a structure (Scheme
4) in which the bridging iodo ligand is trans to the
iminoacyl carbons, similarly to that shown by a related
complex, [Pd2{κ2-C,N-C(dNXy)C6H4NH2-2}2(CNXy)2(µ-
I)]TfO, whose structure was determined by X-ray meth-
ods.30
which could be a model of the proposed intermediate
C.42 We report here further aspects of the reactivity of
16 and more details on complex 17.
The reaction of 16 with 1 equiv of an isocyanide yields
complexes [Pd(κ2-C,S-Arc)I(CNR)] [R ) Xy (18), R ) tBu
(18′)] resulting after bridge-splitting. This behavior is
in contrast to that of the dithioacetal aryl-palladium
complexes 10, because complexes 18 do not evolve to
the homologues of 13, resulting after the insertion of
the isocyanide into the Pd-C bond (Scheme 4). When
16 was reacted with 2 equiv of an isocyanide, complexes
trans-[Pd(κ1-C-Arc)I(CNR)2] [R ) Xy (19), R ) tBu (19′)]
were obtained (Scheme 6). This result also differs from
that obtained from complexes 10 (Scheme 4), not only
because the isocyanide insertion does not occur but also
since the κ2-C,S chelating ligand converts into a κ1-C
ligand after S-Pd bond cleavage.
Com p lexes w ith th e Liga n d CH(STo)C6H(STo)-
2-(OMe)3-3,4,5. We have recently reported that the
iodoarene 9 reacts with “Pd(dba)2” to give the complex
16 by way of an unusual rearrangement involving the
transformation of a 2-dithioacetalaryl ligand into an
alkyl ligand bearing two thioether functions (Chart 2).41
We proposed the mechanism depicted in Scheme 5, in
which 9 adds to Pd(0) to give the expected aryldithio-
acetal derivative A, which would undergo a C-S bond
cleavage giving B. Then, an insertion of the ToS- ligand
into the C-Pd bond would give 16 via a Pd(0) interme-
diate C resulting from B after an intramolecular redox
process. We have more recently communicated the
synthesis of an unusual Pd complex 17 (Scheme 6),
The reaction of 16 with PPh3 (1:4) in the presence of
Tl(TfO) results in the formation of the cationic complex
17, whose structure has been resolved by X-ray diffrac-
tion studies.42 The main features of this structure reveal
that 17 could be considered as intermediate between a
tricoordinate Pd(0) complex with the ligand η2-C,S-
[ToS(+)dCHC6H(STo)-2-(OMe)3-3,4,5] and a square-
planar Pd(II) complex with the ligand κ2-C,S-
[ToSCH(-)C6H(STo)-2-(OMe)3-3,4,5]. Alternatively, if the
coordination of the STo-2 group is considered, it could
be described as intermediate between a tetracoordinate
Pd(0) complex with the ligand (η2-C,S),S-[ToS(+)dCHC6H-
(STo)-2-(OMe)3-3,4,5] and a flattened square-pyramid
Pd(II) complex with the ligand κ3-C,S,S-[ToSCH(-)C6H-

Ortho-Mercuriated and -Palladated Arylacetals
Organometallics, Vol. 23, No. 6, 2004 1303
Sch em e 7
(STo)-2-(OMe)3-3,4,5] (Scheme 6). The partial reduction
of the metal center was postulated as a consequence of
the strong alkyl/PPh3 transphobia if the complex was a
pure Pd(II) complex and of the inoperativity of the
C-donor/P-donor transphobia in Pd(0) complexes. A
similar behavior has been reported when [PdII(CH2C6H4-
OSiR3-4)Br(diphosphine)] was reacted with F- to give
[Pd0(CH2dC6H4dO-4)Br(diphosphine)].54 An additional
support for this proposal was the reaction of 17 with
NaI to give [Pd(κ2-C,S-Arc)I(PPh3)] (20). The facile
substitution of PPh3 by I- could be another consequence
of the strong alkyl/PPh3 transphobia associated with the
residual Pd(II) character of complex 17. This complex
could also be one-pot prepared by an oxidative addition
reaction of 9 to “Pd(dba)2” in the presence of the
appropriate amounts of PPh3 and Tl(TfO). The reaction
of equimolar amounts of 9, “Pd(dba)2”, and PPh3 or of
16 and PPh3 (1:2) also yields the neutral complex cis-
[Pd(κ2-C,S-Arc)I(PPh3)] (20) (Scheme 6). We have not
been able to grow single crystals of complex 20, but we
assume it has a structure similar to that of cis-[Pd(κ2-
C,S-Arc)(CNXy)2]TfO,41 with the P- and C-donor ligands
arranged cis in accordance with their mutual transpho-
bia. The NMR data indicate that 20 is constituted of
only one isomer.
Sp ectr oscop ic P r op er ties of Com p lexes. Most
spectroscopic data of the new compounds are in ac-
cordance with the proposed structures. However, in
complexes 14b and 15b (Scheme 4) only one singlet
integrating for four methyls is observed at room tem-
perature. At -60 °C three singlets appear corresponding
to 3/6/3 protons. This suggests that, at low temperature,
one of the xylyl groups has restricted rotation around
the N-C6H3Me2 bond, making both methyl groups
inequivalent, while the other one has free rotation. The
above data suggest that an interchange between coor-
dinated and inserted XyNC ligands occurs at room
temperature. We propose the series of equilibria de-
picted in Scheme 7 to account for this behavior. The
proposed dissociation of XyNC is in accordance with the
reactions of 14a ,b with complexes 10a ,b to give 13a ,b
explain why 12a ′, 14a , and 15a show only one signal
for the four methylene carbons.
The ν(CtN) band of coordinated isonitriles appears
in the IR spectra at 2170-2222 cm-1, and the ν(CdN)
band of the inserted isonitriles is observed in the range
1632-1668 cm-1
.
X-r a y Difr a ction Stu d ies. The crystal and molec-
ular structures of complexes 4, 5a *, 14a , and 14b have
been determined (Figures 1-4). Compound 4 shows a
square-planar coordination around the palladium atom,
somewhat distorted because of the small bite angle of
the bpy ligand (N(1)-Pd-N(2) 79.15(10)°). The greater
trans influence of the aryl with respect to the chloro
ligand causes the Pd-N(2) distance (2.122(3) Å) to be
longer than the Pd-N(1) bond length (2.050(3) Å). The
molecule shows a weak intramolecular C(bpy)-H‚‚‚Cl
hydrogen bond [C30‚‚‚Cl 3.348(4) Å, H30‚‚‚Cl 2.75 Å,
C30-H30‚‚‚Cl 121.4°]. Weak intermolecular C-H‚‚‚Cl
1
(see above). The H NMR spectra of complexes 19 show
a broadening affecting the signals of the CHPd, the To
groups, and one of the methoxy groups; such signals
sharpen on cooling to -60 °C.
It would be expected that the 13C NMR spectra of
complexes having the κ2-C,S-Ara ligand show the pres-
ence of three resonances assignable to the methylene
carbons. However, this is only true for 14a ′ (see Ex-
perimental Section). Only two signals are observed for
complexes 5a and 5a *. Similarly, among the compounds
containing the ligand Arb, only 14b and 14b′ show the
expected two methylene signals, while in 11b these two
signals are broad and in 5b, 11b* and 12b′ only one
signal is observed. The spectra of 5a , 5a *, 5b, 11b*, 11b,
and 12b′ could be explained assuming that the ortho
1,3-dithiolan-2-yl group underwent an exchange be-
tween the coordinated and the other sulfur through an
S-Pd bond breaking and re-forming process within the
response time of the apparatus. Such an exchange could
be responsible for making similar both ortho and meta
1,3-dithiolan-2-yl groups in Ara complexes, which could
F igu r e 1. Ellipsoid representation of 4 (50% probability).
Selected bond lengths (Å) and angles (deg): Pd-C(1) 1.994-
(3), Pd-N(1) 2.050(3), Pd-N(2) 2.122(3), Pd-Cl 2.2985-
(9), C(1)-Pd-N(1) 95.49(11), N(1)-Pd-N(2) 79.15(10),
C(1)-Pd-Cl 90.05(9), N(2)-Pd-Cl 95.29(8).
(54) Rabin, O.; Vigalok, A.; Milstein, D. Chem. Eur. J . 2000, 6, 454.

1304 Organometallics, Vol. 23, No. 6, 2004
Vicente et al.
F igu r e 2. Ellipsoid representation of 5a * (50% prob-
ability). Selected bond lengths (Å) and angles (deg): Pd-
C(1) 2.0207(19), Pd-P 2.2828(5), Pd-S(1) 2.3286(5), Pd-
Cl 2.3868(6), S(1)-C(8) 1.805(2), S(1)-C(7) 1.820(2), S(2)-
C(9) 1.805(2), S(2)-C(7) 1.837(2), S(3)-C(10) 1.805(2),
S(3)-C(11) 1.805(2), S(4)-C(12) 1.815(3), S(4)-C(10) 1.837-
(2), C(1)-Pd-P 93.76(6), C(1)-Pd-S(1) 83.62(6), P-Pd-
Cl 93.596(19), S(1)-Pd-Cl 89.10(2), C(7)-S(1)-Pd 96.65-
(7), C(2)-C(1)-Pd 117.24(14), C(1)-C(2)-C(7) 119.50(17),
C(2)-C(7)-S(1) 108.23(14).
F igu r e 4. Ellipsoid representation of 14b with 30%
probability ellipsoids and the labeling scheme. Selected
bond lengths (Å) and angles (deg): Pd-C(20) 1.965(3), Pd-
C(30) 2.033(2), Pd-S(1) 2.3200(6), Pd-I 2.7219(3), S(1)-
C(11) 1.810(3), S(1)-C(10) 1.835(2), S(2)-C(10) 1.802(2),
S(2)-C(12) 1.833(2), N(2)-C(20) 1.154(3), N(2)-C(21) 1.406-
(3), N(3)-C(30) 1.251(3), N(3)-C(31) 1.424(3); C(20)-Pd-
C(30) 92.12(9), C(30)-Pd-S(1) 86.87(7), C(20)-Pd-I 90.98-
(7), S(1)-Pd-I 90.059(16), C(20)-N(2)-C(21) 170.3(2),
N(2)-C(20)-Pd 169.9(2), C(30)-N(3)-C(31) 124.9(2), N(3)-
C(30)-C(1) 122.2(2), N(3)-C(30)-Pd 129.09(18), C(1)-
C(30)-Pd 108.74(15).
agreement with the great aryl/phosphine transphobia
(see above). The five-membered metallocycle adopts an
envelope conformation with the sulfur atom out of the
ring main plane. Both thioacetal rings adopt a twist boat
conformation. The most relevant interactions found in
the crystal include an intramolecular C-H‚‚‚Cl and
intermolecular C-H‚‚‚S and C-H‚‚‚Cl weak hydrogen
bonds (see Supporting Information).
The structures of 14a (Figure 3) and 14b (Figure 4)
are similar. In both cases the iodo ligand is located trans
to the iminoacyl carbon, while the isonitrile is trans to
the sulfur atom, avoiding the unfavorable situation
(greater transphobia) that would occur with both carbon
donor ligands in trans position. The short intermolecular
contacts C(1)-H(1)‚‚‚N(3) in 14a [H(1)‚‚‚N(3) 2.49 Å,
C(1)-H(1)‚‚‚N(3) 154°] and C(11)-H(11a)‚‚‚O(3) [H(11a)‚
‚‚O(3) 2.42 Å, C(11)-H(11a)‚‚‚O(3) 161°] and C(12)-
H(12b)‚‚‚O(2) [H(12b)‚‚‚O(2) 2.47 Å, C(12)-H(12b)‚‚‚O(2)
148°] in 14b could be regarded as weak hydrogen bonds.
F igu r e 3. Ellipsoid representation of 14a (solvent omitted)
with 30% probability ellipsoids and the labeling scheme.
Selected bond lengths (Å) and angles (deg): Pd-C(20)
1.965(2), Pd-C(10) 2.0250(19), Pd-S(1) 2.3067(5), Pd-I
2.6995(3), S(1)-C(2) 1.812(2), S(1)-C(1) 1.8318(19), S(2)-
C(1) 1.823(2), S(2)-C(3) 1.833(2), S(3)-C(5) 1.803(3), S(3)-
C(4) 1.834(2), S(4)-C(6) 1.799(3), S(4)-C(4) 1.827(2), C(10)-
N(3) 1.262(2), C(20)-N(2) 1.149(3), C(21)-N(2) 1.403(2),
C(31)-N(3) 1.435(2); C(20)-Pd-C(10) 91.81(8), C(10)-Pd-
S(1) 87.34(5), C(20)-Pd-I 91.27(6), S(1)-Pd-I 89.408(13),
N(3)-C(10)-C(16) 121.78(17), N(3)-C(10)-Pd 127.51(14),
C(16)-C(10)-Pd 110.63(13), N(2)-C(20)-Pd 174.30(18),
C(20)-N(2)-C(21) 171.1(2), C(10)-N(3)-C(31) 120.32(16).
Ack n ow led gm en t. We thank Ministerio de Ciencia
y Tecnolog´ıa, FEDER (BQU2001-0133), and the Fonds
der Chemischen Industrie for financial support. F.S.H.-
M. and B.R. thank Fundacio´n Se´neca (Comunidad
Auto´noma de la Regio´n de Murcia, Spain) and Minis-
terio de Educacio´n y Cultura (Spain), respectively, for
grants.
and C-H‚‚‚O hydrogen bonds have been found in the
crystal (see Supporting Information).
The structure of 5a * shows a square-planar palladium
center, slightly distorted due to the small bite angle of
the chelated ligand (C(1)-Pd-S(1) 83.62(10)°). The
phosphine ligand is trans to the coordinated sulfur atom,
and the chlorine atom is trans to the aryl group, in
Su p p or tin g In for m a tion Ava ila ble: CIF files for 4, 5a *,
14a , and 14b. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM0342964