New acetonyl palladium(II) complexes

Article abstract of DOI:10.1021/om8003288

[Pd(CH₂C(O)Me)Cl]_n (1), reacts with P- and N-donor ligands to afford cis-[Pd{CH₂C(O)Me}Cl(dppf)] (dppf = bis(diphenylphosphino)ferrocene (2)) and [Pd(CH₂C(O)Me)ClL ₂] (L = pyridine = py (3), 4-Me-pyri

Full text of DOI:10.1021/om8003288

3978
Organometallics 2008, 27, 3978–3985
New Acetonyl Palladium(II) Complexes
Jose´ Vicente, Aurelia Arcas,* Jesu´s M. Ferna´ndez-Herna´ndez, and Delia Bautista‡
Grupo de Qu´ımica Organometa´lica, Departamento de Qu´ımica Inorga´nica, Facultad de Qu´ımica,
UniVersidad de Murcia, Apartado 4021, E-30071 Murcia, Spain, and SAI, UniVersidad de Murcia,
Apartado 4021, 30071 Murcia, Spain
ReceiVed April 14, 2008
[Pd{CH2C(O)Me}Cl]n (1), reacts with P- and N-donor ligands to afford cis-[Pd{CH2C(O)Me}Cl(dppf)]
(dppf ) bis(diphenylphosphino)ferrocene (2)) and [Pd{CH2C(O)Me}ClL2] (L ) pyridine ) py (3), 4-Me-
t
pyridine ) Mepy (4), 4-tBu-pyridine ) Bupy (5)). Reaction of 3 or 3-5 with 1 equiv of [Tl(acac)] or
TlTfO and L affords, respectively, [Pd{CH2C(O)Me}(O,O-acac)(py)] (6) or [Pd{CH2C(O)Me}L3]TfO
t
(L ) py (7), Mepy (8), Bupy (9)). The reaction of 9 with 1 equiv of {Ph2P(CH2)2}2PhP (triphos) gave
[Pd{CH2C(O)Me}(triphos)]TfO (10). Complex 1 reacts with norbornene (nbn) followed by addition of
L2 (1:2:1), with 1,5-cyclooctadiene (cod) (1:1) or with 1,1-dimethyl allene (dma) to give [Pd{(nbn)-
CH2C(O)Me}ClL2] (L2 ) 2,2′-bipyridine (bpy) (11), 4,4′-di-tert-butyl 2,2′-bipyridine (dbbpy) (12)),
[Pd{CH2C(O)Me}Cl(cod)] (13), or [Pd{η3-CH2C{CH2C(O)Me}Cl]2 (14), respectively. The structures
of complexes 3, 8, 11, and 13 have been solved by X-ray diffraction studies.
ligand, which leaves available for substitution three coordination
positions at palladium. We have used 1 to prepare neutral mono-
and dinuclear complexes as well as C-palladated ꢀ-ketoenamine
complexes resulting from insertion of one molecule of isocya-
nide into the Pd-acetonyl bond.4,5
Introduction
We are involved in the synthesis of ketonyl metal complexes1–7
because some of these species are intermediates in organic
synthesis.8–10
We have reported the synthesis of the polymer [Pd{CH2C-
(O)Me}Cl]n (1), obtained by transmetalation reactions from
[Hg{CH2C(O)Me}2] and [PdCl2(MeCN)2] or (NMe4)[Pd2Cl6].4
The other methods of synthesis of acetonyl palladium(II)
complexes lead to neutral species always containing strongly
coordinated ligands, such as PPh3,11 N,N,N′,N′-tetramethyleth-
ylenediamine,3 C6F5, C6H4CH2NMe2-2.12 In contrast with these
complexes, 1 offers the opportunity of preparing neutral acetonyl
complexes simply by bridging splitting reactions with neutral
ligands or cationic acetonyl complexes by replacing the chloro
We describe our last report on the synthetic use of 1, showing
the preparation of new types of neutral and the first cationic
acetonyl complexes resulting from its reaction with a variety
of ligands (neutral and anionic, monodentate N donor, di- and
tridentate P donor). The insertion of alkenes into Pd-C bonds
has attracted interest, since it constitutes a key step in many
important processes such as the Heck reaction,9,13 the palladium-
catalyzed polimerization of olefins,14,15 and the copolymerization
* To whom correspondence regarding the synthesis and solution
characterization of complexes should be addressed. E-mail: aurelia@um.es
(A.A.); jvs@um.es (J.V). WWW: http://www.scc.um.es/gi/gqo/.
‡ To whom correspondence regarding the X-ray diffraction study of
complexes should be sent. E-mail: dbc@um.es.
(1) (a) Vicente, J.; Bermu´dez, M. D.; Chicote, M. T.; Sa´nchez-Santano,
M. J. J. Chem. Soc., Chem. Commun. 1989, 141. (b) Vicente, J.; Bermu´dez,
M. D.; Chicote, M. T.; Sa´nchez-Santano, M. J. J. Chem. Soc., Dalton Trans.
1990, 1945. (c) Vicente, J.; Bermu´dez, M. D.; Escribano, J.; Carrillo, M. P.;
Jones, P. G. J. Chem. Soc., Dalton Trans. 1990, 3083. (d) Vicente, J.; Arcas,
A.; Ferna´ndez-Herna´ndez, J. M.; Sironi, A.; Masciocchi, N. Chem. Commun.
2005, 1267.
(7) Vicente, J.; Bermu´dez, M. D.; Carrillo, M. P.; Jones, P. G. J.
Organomet. Chem. 1993, 456, 305.
(8) (a) Culkin, D. A.; Hartwig, J. F. Acc. Chem. Res. 2003, 36, 234. (b)
Sodeoka, M.; Hamashima, Y. Bull. Chem. Soc. Jpn. 2005, 78, 941. (c) Chen,
G. S.; Kwong, F. Y.; Chan, H. O.; Yu, W. Y.; Chan, A. S. C. Chem.
Commun. 2006, 1413. (d) Ogoshi, S.; Morimoto, T.; Nishio, K.; Ohe, K.;
Murai, S. J. Org. Chem. 1993, 58, 9. (e) Carfagna, C.; Musco, A.; Sallese,
G.; Santi, R.; Fiorani, T. J. Org. Chem. 1991, 56, 261. (f) Palucki, M.;
Buchwald, S. L. J. Am. Chem. Soc. 1997, 119, 11108. (g) Satoh, T.;
Kawamura, Y.; Miura, M.; Nomura, M. Angew. Chem., Int. Ed. Engl. 1997,
36, 1740.
(2) (a) Vicente, J.; Abad, J. A.; Cara, G.; Jones, P. G. Angew. Chem.,
Int. Ed. Engl. 1990, 29, 1125. (b) Vicente, J.; Bermu´dez, M. D.; Carrillo,
M. P.; Jones, P. G. J. Chem. Soc., Dalton Trans. 1992, 1975. (c) Vicente,
J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Bautista, D. Organometallics
2006, 25, 4404.
(3) Vicente, J.; Abad, J. A.; Chicote, M. T.; Abrisqueta, M.-D.; Lorca,
J.-A.; Ram´ırez de Arellano, M. C. Organometallics 1998, 17, 1564.
(4) Vicente, J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Bautista, D.
Organometallics 2001, 20, 2767.
(9) Tsuji, J. Palladium Reagents and Catalysts; John Wiley: Chinchester,
U.K., 1995.
(10) Ito, Y.; Hirao, T.; Saegusa, T. J. Org. Chem. 1978, 43, 1011.
(11) (a) Albeniz, A. C.; Catalina, N. M.; Espinet, P.; Redon, R.
Organometallics 1999, 18, 5571. (b) Suzuki, K.; Yamamoto, H. Inorg. Chim.
Acta 1993, 208, 225. (c) Bertani, R.; Castellani, C. B.; Crociani, B. J.
Organomet. Chem. 1984, 269, C15.
(12) Ruiz, J.; Rodr´ıguez, V.; Cutillas, N.; Pardo, M.; Pe´rez, J.; Lo´pez,
G.; Chaloner, P.; Hitchcock, P. B. Organometallics 2001, 20, 1973.
(13) (a) Heck, R. F. Palladium Reagents in Organic Syntheses; Academic
Press: London, U.K., 1985. (b) Beletskaya, I. P.; Cheprakov, A. V. Chem.
ReV. 2000, 100, 3009. (c) Dounay, A. B.; Overman, L. E. Chem. ReV. 2003,
103, 2945.
(14) (a) Johnson, L. K.; Killian, C. M.; Brookhart, M. J. Am. Chem.
Soc. 1995, 117, 6414. (b) Yamamoto, A. J. Chem. Soc., Dalton Trans. 1999,
1027. (c) Ittel, S. D.; Johnson, L. K.; Brookhart, M. Chem. ReV. 2000, 100,
1169.
(5) Vicente, J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Bautista, D.;
Jones, P. G. Organometallics 2005, 24, 2516.
(6) (a) Vicente, J.; Abad, J. A.; Cara, G.; Gutierrez-Jugo, J. F. J. Chem.
Soc., Dalton Trans. 1992, 2481. (b) Vicente, J.; Bermu´dez, M. D.; Carrio´n,
F. J. Inorg. Chim. Acta 1994, 220, 1. (c) Vicente, J.; Abad, J. A.; Bergs,
R.; Jones, P. G.; Bautista, D. J. Chem. Soc., Dalton Trans. 1995, 3093. (d)
Vicente, J.; Chicote, M. T.; Huertas, S.; Ram´ırez de Arellano, M. C.; Jones,
P. G. Eur. J. Inorg. Chem. 1998, 511. (e) Vicente, J.; Chicote, M. T.; Rubio,
C.; Ram´ırez de Arellano, M. C.; Jones, P. G. Organometallics 1999, 18,
2750.
(15) Mecking, S.; Johnson, L. K.; Wang, L.; Brookhart, M. J. Am. Chem.
Soc. 1998, 120, 888.
10.1021/om8003288 CCC: $40.75
2008 American Chemical Society
Publication on Web 06/27/2008

New Acetonyl Palladium(II) Complexes
Organometallics, Vol. 27, No. 15, 2008 3979
2
of alkenes and CO.15,16 However, only a few examples of alkene
insertion into the Pd-ketonyl bond have been reported.10,17 We
describe here a complex resulting from insertion of an alkene
(norbornene) into the Pd-acetonyl bond and its crystal structure,
which is the first example of a fully characterized palladium
complex of this type.
Allenes have found increasing applications in transition metal-
catalyzed reactions for organic and polymer synthesis.18 Orga-
nopalladium complexes react with allenes to afford π-allyl
complexes.19–21 We also report the first example of a reaction
affording a π-allyl complex resulting after insertion of an allene
into a Pd-ketonyl bond.
(d, JPP ) 29 Hz). Anal. Calcd for C37H33ClFeNOP2Pd: C, 58.99;
H, 4.42. Found: C, 58.63; H, 4.53.
Synthesis of [Pd{CH2C(O)Me}Cl(py)2] (3). To a suspension
of 1 (195 mg, 0.98 mmol) in acetone (40 mL) was added pyridine
(171 µL, 2.11 mmol). The suspension was stirred until 1 dissolved
and then was filtered through Celite. The filtrate was concentrated
(ca. 2 mL), and addition of Et2O (20 mL) gave a suspension that
was filtered off. The solid was washed with Et2O (2 × 5 mL) and
air-dried to give 3 as a yellow solid. Yield: 322 mg, 92%. Mp:
114-116 °C. IR (Nujol, cm-1): ν(CdO) 1636 (s); ν(Pd-Cl) 280
(m). 1H NMR (200 MHz, CDCl3, trans:cis isomers 10:1): trans
isomer δ 8.86 (m, 4H, o-H), 7.80 (m, 2H, p-H), 7.40 (m, 4H, m-H),
2.64 (s, 2H, CH2), 1.72 (s, 3H, Me); cis isomer δ 8.73 (m, 2 H,
o-H, py cis to acetonyl), 8.41 (m, 2 H, o-H, py trans to acetonyl),
7.80 (m, 1 H, p-H, py trans to acetonyl), 7.70 (m, 2 H, p-H, py cis
to acetonyl), 7.40 (m, 2 H, m-H, py cis to acetonyl), 7.25 (m, 2 H,
m-H, py trans to acetonyl), 2.81 (s, 2H, CH2), 2.37 (s, 3H, Me).
13C{1H} NMR (50.32 MHz, CDCl3): trans isomer δ 209.3 (CO),
152.7 (o-C), 138.0 p-C), 125.2 (m-C), 32.1 (CH2), 30.0 (Me); cis
isomer δ 153.2 (py), 152.2 (py), 138.5 (py), 125.7 (py), 124.8 (py),
30.8 (Me), 22.9 (CH2). Anal. Calcd for C13H15ClN2OPd: C, 43.72;
H, 4.23; N, 7.84. Found: C, 43.45; H, 4.21; N, 7.82. Single crystals
of 3 were obtained by slow diffusion of Et2O into a solution of 3
in CHCl3.
Synthesis of [Pd{CH2C(O)Me}Cl(Mepy)2] (4). This yellow
complex was prepared as described for 3, using 1 (100 mg, 0.50
mmol) in CH2Cl2 (10 mL) and 4-methyl pyridine (Mepy, 104 µL,
1.06 mmol). Yield: 174 mg, 90%. Dec pt: 126-128 °C. IR (Nujol,
cm-1): ν(CdO) 1638 (s); ν(Pd-Cl) 270 (m). 1H NMR (300 MHz,
CDCl3, trans:cis isomers 10:1): trans isomer δ 8.64-8.66 (m, 4H,
o-H), 7.18-7.2 (m, 4H, m-H), 2.61 (s, 2H, CH2), 2.40 (s, 6H,
Mepy), 1.74 (s, 3H, MeCO); cis isomer δ 8.52 (m, 2H, o-H), 8.26
(m, 2H, o-H), 2.75 (s, 2H, CH2). 13C{1H} NMR (75.43 MHz,
CDCl3): trans isomer δ 209.3 (CO), 152.0 (CH), 150.0 (C), 126.1
(CH), 32.0 (CH2), 30.1 (MeCO), 21.0 (Mepy); cis isomer δ 152.4
(o-C), 151.4 (o-C), 126.5 (m-C), 30.8 (MeCO), 23.0 (CH2), 21.0
(Mepy). Anal. Calcd for C15H19ClN2OPd: C, 46.77; H, 4.97; N,
7.27. Found: C, 46.40; H, 4.88; N, 7.14.
Experimental Section
Unless otherwise stated, the reactions were carried out without
precautions to exclude light or atmospheric oxygen or moisture.
Melting points were determined on a Reicher apparatus and are
uncorrected. Elemental analyses were carried out with a Carlo Erba
1106 microanalyzer. Molar conductivities were measured on a ca.
5 × 10-4 M acetone solution with a Crison Micro CM2200
conductimeter. IR spectra were recorded on a Perkin-Elmer 16F
PC FT-IR spectrometer with Nujol mulls between polyethylene
sheets. NMR spectra were recorded in a Brucker AC 200 or Avance
300 or 400 spectrometers at room temperature. Chemical shifts were
referred to TMS (1H, 13C), H3PO4 (31P), or CFCl3 (19F). When
needed, NMR assignments were performed with the help of APT,
DEPT, COSY, one-dimensional NOE experiments, and HETCOR
techniques. Complex 1 was prepared as reported previously.4
Synthesis of [Pd{CH2C(O)Me}Cl(dppf)] (2). To a suspension
of 1 (100 mg, 0.50 mmol) in dry THF (2 mL) was added
bis(diphenylphosphino)ferrocene (dppf) (279 mg, 0.50 mmol) under
N2. The mixture was stirred for 15 min, the solution was
concentrated to dryness, and Et2O (20 mL) was added. The resulting
suspension was filtered and the solid washed with Et2O (10 mL)
to give 2 as an orange solid. Yield: 337 mg, 90%. Mp: 140 °C. IR
(Nujol, cm-1): ν(CdO) 1640; ν(Pd-Cl) 294. 1H NMR (200 MHz,
CDCl3): δ 7.97-7.88 (m, 4H, Ph), 7.69-7.59 (m, 4H, Ph),
7.46-7.37 (m, 8H, Ph), 7.29-7.20 (m, 4H, Ph), 4.73 (m, 2H, Cp),
4.52 (m, 2H, Cp), 4.13 (m, 2H, Cp), 3.33 (m, 2H, Cp), 2.70 (dd,
Synthesis of [Pd{CH2C(O)Me}Cl(tBupy)2] (5). This complex
was prepared as described for 3, using 1 (150 mg, 0.75 mmol) in
CH2Cl2 (10 mL) and 4-tert-butylpyridine (tBupy, 234 µL, 1.58
mmol). The final solution was concentrated (ca. 2 mL) and cooled
in a water/ice bath. Addition of n-pentane (15 mL) and vigorous
stirring gave a suspension that was filtered off, and the solid was
washed with n-pentane (2 × 5 mL) and air-dried to give 5 as a
light-yellow solid. Yield: 324 mg, 91.5%. Dec pt: 128 °C. IR (Nujol,
cm-1): ν(CdO) 1638 (s); ν(Pd-Cl) 278 (m). 1H NMR (300 MHz,
CDCl3 trans:cis isomers 12:1): trans isomer δ 8.72-8.70 (m, 4H),
7.34-7.36 (m, 4H), 2.64 (s, 2H, CH2), 1.73 (s, 3H, MeCO), 1.31
2
2
2H, CH2, JHPcis ) 5.2 Hz, JHPtrans ) 12.6 Hz), 2.27 (s, 3H, Me).
31P{1H} NMR (80.95 MHz, CDCl3): δ 38.42 (JPP ) 29 Hz), 17.2
(16) (a) Sen, A. Acc. Chem. Res. 1993, 26, 303. (b) Bianchini, C.; Meli,
A. Coord. Chem. ReV. 2002, 225, 35.
(17) (a) Ito, Y.; Aoyama, H.; Hirao, T.; Mochizuki, A.; Saegusa, T.
J. Am. Chem. Soc. 1979, 101, 494. (b) Ito, Y.; Aoyama, H.; Saegusa, T.
J. Am. Chem. Soc. 1980, 102, 4519.
(18) (a) Zimmer, R.; Dinesh, C. U.; Nandanan, E.; Khan, F. A. Chem.
ReV. 2000, 100, 3067. (b) Hong, S.; Marks, T. J. Acc. Chem. Res. 2004,
37, 673. (c) Ma, S. M. Chem. ReV. 2005, 105, 2829.
t
(s, 18H, Bu); cis isomer δ 8.59 (m, 2H, o-H), 8.29 (m, 2H, o-H),
7.23 (m, 2H), 2.78 (s, 2H, CH2), 2.37 (s, 3H, MeCO). 13C{1H}
NMR (75.43 MHz, CDCl3): trans isomer δ 209.3 (CO), 162.3 (Cp),
151.8 (o-C), 122.2 (m-C), 35.0 (CMe3), 31.8 (CH2), 30.0 (CMe3),
30.0 (MeCO); cis isomer δ 152.5 (o-C), 151.5 (o-C), 122.8 (m-C),
121.8 (m-C), 30.9 (MeCO), 22.9 (CH2). Anal. Calcd for
C21H31ClN2OPd: C, 53.74; H, 6.66; N, 5.97. Found: C, 53.35; H,
6.69; N, 5.86.
(19) (a) Ankersmit, H. A.; Loken, B. H.; Kooijman, H.; Spek, A. L.;
Vrieze, K.; van Koten, G. Inorg. Chim. Acta 1996, 252, 141. (b) Delis,
J. G. P.; Groen, J. H.; Vrieze, K.; van Leeuwen, P.; Veldman, N.; Spek,
A. L. Organometallics 1997, 16, 551. (c) Yagyu, T.; Suzaki, Y.; Osakada,
K. Organometallics 2002, 21, 2088. (d) Canovese, L.; Visentin, F.; Chessa,
G.; Santo, C.; Uguagliati, P.; Bandoli, G. J. Organomet. Chem. 2002, 650,
43. (e) Canovese, L.; Chessa, G.; Santo, C.; Visentin, F.; Uguagliati, P.
Inorg. Chim. Acta 2003, 346, 158. (f) Canovese, L.; Visentin, F.; Chessa,
G.; Uguagliati, P.; Santo, C.; Bandoli, G.; Maini, L. Organometallics 2003,
22, 3230. (g) Sirlin, C.; Chengebroyen, J.; Konrath, R.; Ebeling, G.; Raad,
I.; Dupont, J.; Paschaki, M.; KotzybaHibert, F.; HarfMonteil, C.; Pfeffer,
M. Eur. J. Org. Chem. 2004, 1724.
(20) (a) Ankersmit, H. A.; Veldman, N.; Spek, A. L.; Eriksen, K.;
Goubitz, K.; Vrieze, K.; van Koten, G. Inorg. Chim. Acta 1996, 252, 203.
(b) Canovese, L.; Visentin, F.; Chessa, G.; Uguagliati, P.; Bandoli, G.
Organometallics 2000, 19, 1461.
(21) (a) Vicente, J.; Abad, J.-A.; Bergs, R.; Ramirez de Arellano, M. C.;
Martinez-Viviente, E.; Jones, P. G. Organometallics 2000, 19, 5597. (b)
Yagyu, T.; Hamada, M.; Osakada, K.; Yamamoto, T. Organometallics 2001,
20, 1087. (c) Chengebroyen, J.; Linke, M.; Robitzer, M.; Sirlin, C.; Pfeffer,
M. J. Organomet. Chem. 2003, 687, 313.
Synthesis of [Pd{CH2C(O)Me}(acac)(py)] (6). To a solution
of 3 (90 mg, 0.25 mmol) in acetone (25 mL) was added Tl(acac)
(77 mg, 0.25 mmol). The resulting suspension was stirred for 15
min and filtered through Celite. The filtrate was concentrated to
dryness, and n-hexane (5 mL) was slowly added to give an oil that
was stirred in an acetone/ice bath to give a solid, which was filtered
off, washed with n-hexane (5 mL), and air-dried to give 6 as a
yellow solid. Yield: 40 mg, 46%. Mp: 67-68 °C. IR (cm-1):
ν(CdO) 1650; ν(CdO, acac) 1582, 1516. 1H RMN (200 MHz,
CDCl3): δ 8.79-8.83 (m, 2H, py), 7.73-7.82 (m, 1H, py),

3980 Organometallics, Vol. 27, No. 15, 2008
Vicente et al.
7.33-7.40 (m, 2H, py), 5.35 (s, 1H, acac), 2.64 (s, 2H, CH2), 2.20
(s, 3H, MeCOCH2), 2.00 (s, 3H, Me, acac), 1.93 (s, 3H, Me, acac).
13C{1H} NMR (100.8 MHz, CDCl3): δ 212.6 (MeCOCH2), 187.6
and 185.4 (CO, acac), 152.4 (o-C), 137.5 (Cp), 125.0 (m-C), 99.9
(CH, acac), 30.2 (MeCOCH2), 27.7 (Me, acac), 27.1 (Me, acac),
26.5 (CH2). Anal. Calcd for C13H17NO3Pd: C, 45.70; H, 5.01; N,
4.10. Found: C, 45.40; H, 5.02; N, 4.07.
9 H, tBu). 13C{1H} NMR (50.30 MHz, CDCl3): δ 212.6 (CO), 163.5
(C py cis to R), 162.9 (C py trans to R), 151.70 (CH py cis to R),
149.4 (CH py trans to R), 123.3 (CH py cis to R), 122.9 (CH py
trans to R), 35.1 (CMe3, cis to R), 35.0 (CMe3, trans to R), 30.6
(MeCO), 30.1 (CMe3), 27.8 (CH2). 19F NMR (282.20 MHz, CDCl3):
δ -78.14. Anal. Calcd for C31H44F3N3O4PdS: C, 51.84; H, 6.18;
N, 5.85; S, 4.46. Found: C, 51.42; H, 6.19; N, 6.10; S, 4.07.
Synthesis of [Pd{CH2C(O)Me}(triphos)]TfO · 0.5THF (10). To
a solution 9 (81.7 mg, 0.11 mmol) in dry THF (4 mL) was added
{Ph2P(CH2)2}2PhP (triphos, 61 mg, 0.11 mmol) under N2. After
15 min the solution was concentrated and Et2O (2 mL) was added.
The resulting suspension was filtered off, and the solid was washed
with Et2O (5 mL) and air-dried to give 10 as a colorless solid.
Yield: 77 mg, 74%. Mp: 182-184 °C. ΛM (acetone, 5 × 10-4):
Synthesis of [Pd{CH2C(O)Me}(py)3]TfO (7). TlOTf (103 mg,
0.29 mmol) was added to a solution of 3 (100 mg, 0.28 mmol) in
acetone (20 mL). Pyridine (25 µL, 0.3 mmol) was added to the
resulting suspension, which was stirred for 15 min and concentrated
to dryness, and CH2Cl2 was added (20 mL). The resulting
suspension was stirred for 20 min and filtered through Celite. The
filtrate was concentrated (ca. 3 mL) and Et2O was slowly added.
The mixture, containing an oil, was stirred for 1 h at 0 °C to give
a suspension, which was filtered off. The solid was washed with
Et2O (2 × 5 mL), recrystalized from CH2Cl2/Et2O, and air-dried
to give 7 as a yellow solid. Yield: 125 mg, 81%. Mp: 102-104
°C. ΛM (acetone, 4.7 × 10-4 M): 149 Ω-1 cm2 mol-1. IR (Nujol,
cm-1): ν(CdO) 1650 (s). 1H NMR (300 MHz, CDCl3): δ
8.98-8.97 (m, 4H, py cis to acetonyl), 8.67-8.65 (m, 2H, py trans
to acetonyl), 7.86-7.81 (m, 2H, py cis to acetonyl), 7.74-7.69
(m, 1H, py trans to acetonyl), 7.48-7.43 (m, 4H, py cis to acetonyl),
7.36-7.32 (m, 2H, py trans to acetonyl), 2.60 (s, 2H, CH2), 1.78
(s, 3H, Me). 13C{1H} NMR (75.43 MHz, CDCl3): δ 211.6 (CO),
152.3 (C py cis to acetonyl), 149.8 (C py trans to acetonyl), 138.7
(C py cis to acetonyl), 138.5 (C py trans to acetonyl), 126.2 (C py
cis to acetonyl), 125.9 (C py trans to acetonyl), 30.6 (Me),
28.1(CH2). Anal. Calcd for C19H20ClF3N3O4PdS: C, 41.50; H, 3.67;
N, 7.64; S, 5.83. Found: C, 41.30; H, 3.40; N, 7.60; S, 5.63.
Synthesis of [Pd{CH2C(O)Me}(Mepy)3]TfO · H2O (8). To a
suspension of 1 (150 mg, 0.75 mmol) in acetone (7 mL) were added
Mepy (240 µL, 2.46 mmol) and TlTfO (271 mg, 0.77 mmol). The
resulting suspension was stirred for 30 min and then was filtered
through Celite. The filtrate was concentrated to dryness, extracted
with CH2Cl2 (20 mL), and filtered through Celite. The filtrate was
concentrated (ca. 1 mL) and Et2O (5 mL) was added. The mixture,
containing an oil, was stirred in an acetone/ice bath to give a
suspension, which was filtered off to give 8 as a colorless solid.
Yield: 373 mg, 81%. Mp: 94 °C. ΛM (acetone, 4.72 × 10-4): 120
Ω-1 cm2 mol-1. IR (cm-1): ν(CdO) 1650; ν(OH) 3426. 1H NMR
(300 MHz, CDCl3): δ 8.74-8.72 (m, 4H, py cis to R), 8.39-8.37
(m, 2H, py trans to R), 7.27-7.24 (m, 4H, py cis to R), 7.14-7.12
(m, 2H, py trans to R), 2.54 (s, 2H, CH2), 2.39 (s, 6H, Mepy cis to
R), 2.27 (s, 3H, Mepy trans to R), 1.76 (s, 3H, MeCO). 13C{1H}
NMR (75.43 MHz, CDCl3): δ 212.2 (CO), 151.5 (CH py cis to R),
151.13 (C py cis to R), 150.70 (C py trans to R), 149.2 (CH py
trans to R), 127.1 (CH py cis to R), 126.8 (CH py trans to R), 30.7
(MeCO), 27.8 (CH2), 21.1 (Mepy cis to R), 21.0 (Mepy trans to
R). 19F NMR (282.20 MHz, CDCl3): δ -78.14. Anal. Calcd for
C22H28F3N3O5PdS: C, 43.32; H, 4.63; N, 6.89; S, 5.26. Found: C,
43.34; H, 4.55; N, 6.99; S, 5.02. Single crystals of 8 · H2O were
obtained by slow diffusion of Et2O into a solution of 8 in acetone.
Synthesis of [Pd{CH2C(O)Me}(tBupy)3]TfO (9). To a suspen-
sion of 1 (88 mg, 0.44 mmol) in acetone (3 mL) was added tBupy
(0.2 mL, 1.35 mmol). Addition of KTfO (88 mg, 0.46 mmol) gave
a suspension, which was concentrated to dryness, extracted with
CH2Cl2 (5 mL), and filtered through Celite. The filtrate was
concentrated to dryness and n-pentane (10 mL) was added. The
mixture, containing an oil, was stirred in an acetone/ice bath to
give a suspension, which was filtered off, washed with n-pentane
(5 mL), and air-dried to give 9 as a colorless solid. Yield: 240 mg,
1
158 Ω-1 cm2 mol-1. IR (cm-1): ν(CdO) 1628. H NMR (300
MHz, CDCl3): δ 7.71-7.38 (m, 25H, Ph), 3.74 (m, 2H, CH2, THF),
3.38-3.33 (m, 2H, CH2, triphos), 3.23-3.18 (m, 2H, CH2, triphos),
3.10-2.78 (m, 2H, CH2, triphos), 2.50-2.38 (m, 2H, CH2, triphos),
2.51 (dt, 2H, CH2C(O), 3JHPcis ) 5.1 Hz, 3JHPtrans ) 10.2 Hz), 1.85
(m, 2H, CH2, THF). 1.21 (s, 3H, Me). 31P{1H} (121.42 MHz,
CDCl3): δ 110.1 (t, P trans to R, 2JPP ) 19.6 Hz), 48.3 (d, P cis to
R, 2JPP ) 19.6 Hz). 13C{1H} NMR (75.40 MHz, CDCl3): δ 210.3
(CO), 133.4-131.9 (m, CH, Ph) 129.7-129.3 (m, CH, Ph),
128.6-127.4 (m, C, Ph), 67.9 (THF), 35.0 (dt, CH2CO, 2JCPtrans
)
)
62 Hz, 2JCPcis ) 3.3 Hz), 30.0 (Me), 26.0 (dt, CH2, triphos, 2JCP
2
62 Hz, JCPcis ) 3.3 Hz), 25.5 (THF). 19F NMR (282.20 MHz,
CDCl3): δ -78.1. Anal. Calcd for C40H42F3O4.5PdP3S: C, 54.40;
H, 4.79; S, 3.63. Found: C, 54.01; H, 4.73; S, 3.49.
Synthesis of [Pd{C7H10[CH2C(O)Me]}Cl(bpy)] (11). To a
solution of norbornene (110 mg, 1.16 mmol) in dry MeCN (3 mL)
was added 1 (116 mg, 0.58 mmol) under N2. The resulting
suspension was stirred for 1 h and filtered under N2. Bpy (91 mg,
0.58 mmol) was added to the filtrate to give a suspension, which
was filtered off. The filtrate was concentrated (0.5 mL), Et2O (10
mL) was added, and the precipitate was filtered off; the solid was
washed with Et2O (3 mL) and air-dried to give 11 as a yellow solid.
Yield: 131 mg, 50%. Dec pt: 149 °C. IR (cm-1): ν(CdO) 1704;
ν(Pd-Cl) 318.1H NMR (400 MHz, CDCl3): δ 9.35 (m, 1H, H6′),
8.80 (m, 1H, H6), 8.40-8.02 (m, 3H, bpy, H3, H3′, H4), 7.95 (m,
1H, H4′), 7.63 (m, 1H, H5), 7.51 (m, 1H, H5′), 3.47 (dd, 1H,
2
3
CH2C(O), JHH ) 17.3, JHH ) 6.2 Hz), 2.83 (dd, 1H, CH2C(O),
3
2JHH ) 17.3, JHH ) 7.9 Hz), 2.52 (m, 1H, H12), 2.46 (m, 1H,
H7), 2.22 (m, 2H, H8 and H13), 2.07 (s, 3H, Me), 1.87 (m, 1H,
H9), 1.59 (m, 1H, H10′), 1.31 (m, 2H, H10 and H11), 1.16 (m,
1H, H13′), 1.11 (m, 1H, H11′). 13C{1H} NMR (100.8 MHz,
CDCl3): δ 210.1 (CO), 155.9 (C, bpy), 152.4 (C, bpy), 149.2 (C6′),
148.9 (C6), 138.4 (C4), 138.3 (C4′), 126.4 (C5), 126.1 (C5′), 122.1
(C3 or C3′), 121.1 (C3 or C3′), 51.5 (C7), 50.9 (CH2CO), 46.3
(C12), 46.1 (C8), 42.7 (C9), 36.3 (C13), 31.5 (Me), 31.2 (C11),
29.5 (C10). Anal. Calcd for C20H23ClN2OPd: C, 53.47; H, 5.16;
N, 6.24. Found: C, 53.14; H, 5.15; N, 6.42. Single crystals of 11
were obtained by slow diffusion of Et2O into a solution of 11 in
acetone.
76%. Mp: 119 °C. ΛM (acetone, 4.8 × 10-4): 109 Ω-1 cm2 mol-1
.
IR (cm-1): ν(CdO) 1644. 1H NMR (300 MHz, CDCl3): δ
8.83-8.81 (m, 4H, py cis to R), 8.47-8.50 (m, 2H, py trans to R),
7.43-7.41 (m, 4H, py cis to R), 7.31-7.28 (m, 2H, py trans to R),
Synthesis of [Pd{C7H10[CH3C(O)Me]}Cl(dbbpy)] (12). To a
solution of 1 (127 mg, 0.635 mmol) in dry MeCN (5 mL) was
t
2.53 (s, 2H, CH2), 1.72 (s, 3 H, Me), 1.29 (s, 18 H, Bu), 1.21 (s,

New Acetonyl Palladium(II) Complexes
Organometallics, Vol. 27, No. 15, 2008 3981
Scheme 1
added norbornene (120 mg, 1.27 mmol) under N2. The resulting
suspension was stirred for 1 h and then filtered through Celite. To
the filtrate was added dbbpy (170 mg, 0.635 mmol) to give a
suspension, which was concentrated (3 mL) and then filtered off,
washed with n-pentane (5 mL), and air-dried, to give 12 as a yellow
solid. The filtrate was concentrated, Et2O was added, and the
suspension was filtered to give a second crop of 12. Yield: 170
mg, 47%. IR (cm-1): ν(CdO) 1714; ν(Pd-Cl) 326. 1H NMR (300
MHz, CDCl3): δ 9.21 (m, 1H, dbbpy), 8.69 (m, 1H, dbbpy), 7.96
(m, 1H, dbbpy), 7.90 (m, dbbpy), 7.59 (m, 1H, dbbpy), 7.48 (m,
1H, dbbpy), 3.45 (dd, 1H, CH2C(O), 2JHH ) 17.6, 3JHH ) 6.3 Hz),
2
3
2.89 (dd, 1H, CH2C(O), JHH ) 17.6, JHH ) 8.4 Hz), 2.50-2.47
(m, 2H, H7 and H12), 2.24-2.18 (m, 2H, H8 and H13), 2.10 (s,
3H, Me), 1.87 (m, 1H, H9), 1.60-1.53 (m, 1H, H10′), 1.44 (s, 9H,
t
tBu), 1.40 (s, 9H, Bu), 1.35-1.25 (m, 2H, H10 and H11), 1.15
(m, 1H, H13′), 1.11 (m, 1H, H11′). 13C{1H} NMR (75.45 MHz,
CDCl3): δ 210.4 (CO), 162.8 (C, dbbpy), 156.3 (C, dbbpy), 152.8
(C, dbbpy), 149.1 (C, dbbpy), 148.7 (C, dbbpy), 123.7 (C, dbbpy),
123.4 (C, dbbpy), 118.6 (C, dbbpy), 117.4 (C, dbbpy), 51.1 (CH2),
50.5 (C7), 46.3 (C12), 46.2 (C8), 42.7 (C9), 36.2 (C13), 35.4
(CMe3), 35.3 (CMe3), 31.6 (Me), 31.3 (C11), 30.4 (CMe3), 30.2
(CMe3), 29.7 (C10). Anal. Calcd for C28H39ClN2OPd: C, 59.89; H,
7.00; N, 4.99. Found: C, 58.66; H, 7.61; N, 5.01. See discussion.
Synthesis of [Pd{CH2C(O)Me}Cl(cod)] (13). To a suspension
of 1 (150 mg, 0.75 mmol) in dry THF (15 mL) was added cod
(104 µL, 0.85 mmol) under N2. When the solid was disolved, the
reaction mixture was filtered under N2 and the filtrate was
concentrated (ca. 3 mL). Addition of n-pentane (20 mL) gave a
suspension that was stirred in an acetone/ice bath for 20 min and
filtered under N2. The solid was washed with n-hexane (2 × 5 mL)
and air-dried to give 13 as a yellow solid. Yield: 188 mg, 81%.
58.7 CH2C(O)), 48.6 (CH2, allene), 29.9 (MeCO), 24.3 (Me, allene),
23.4 (Me, allene). Anal. Calcd for C16H26Cl2O2Pd2: C, 35.95; H,
4.91. Found: C, 35.63; H, 4.90.
X-ray Structure Determinations of Complexes 3, 8, 11,
and 13. Complexes 3 and 13 were measured on a Siemmens P4
diffractometer. Structure 11 was measured on a Bruker Smart APEX
diffractometer. Data were collected using monochromated Mo KR
radiation in ω scan mode. Structure 8 was measured on a Bruker
Smart 1000 diffractometer in w and f scan modes. Absorption
corrections were applied on the basis of psi-scans for structures 3
and 13 and multiscans (Program SADABS) for structures 8 and
11. All structures were refined anisotropically on F2. The methyl
groups were refined using rigid groups (AFIX 137), water hydro-
gens in compound 8 were refined as free with DFIX, and the other
hydrogens were refined using a riding model. Special features:
Complex 8: The triflate anion is disordered over three positions
(0.67:0.24:0.09). An unexpected difference peak was tentatively
identified as a water molecule. Reasonable hydrogen sites for the
water could be located and refined.
1
Dec pt: 100 °C. IR (cm-1): ν(CdO) 1648. H NMR (200 MHz,
C6D6): δ 5.71 (2H, CH, cod), 5.10 (2H, CH, cod), 3.00 (2H,
CH2CO), 2.53 (3H, Me), 1.40-1.81 (8H, CH2, cod). 13C{1H} NMR
(50.32 MHz, C6D6): δ 208.9 (CO), 123.3 (CH, cod), 107.0 (CH,
cod), 35.8 (CH2CO), 31.3 (MeCO), 30.8 (CH2, cod), 27.4 (CH2,
cod). Anal. Calcd for C11H17ClOPd: C, 43.02; H, 5.58. Found: C,
43.0; H, 5.52. Single crystals of 13 were obtained by slow diffusion
of Et2O into a solution of 13 in CDCl3.
Results and Discussion
Synthesis of [Pd2{η3-CH2C[CH2C(O)Me]CMe2}2(µ-Cl)2] (14).
A solution of 1 (106 mg, 0.54 mmol) in dry MeCN (5 mL) was
stirred with 3-methyl-1,2-butadiene (63.8 µL, 0.64 mmol) under
N2 for 1 h and then filtered through Celite and concentrated to
dryness. The residue was stirred with n-pentane (10 mL) and the
resulting suspension was filtered. The solid was washed with
n-pentane (5 mL) and air-dried to give 14 as a pale yellow solid.
Yield: 110 mg, 77%. Dec pt: 180 °C. IR (cm-1): ν(CdO) 1714;
ν(Pd-Cl) 260, 240. 1H NMR (200 MHz, CDCl3): δ 3.78 (HA, AB
Reactions of [Pd{CH2C(O)Me}Cl]n (1) with P- and N-
Donor Ligands to Give Neutral Complexes. The reaction of
1 with 1 equiv of bis(diphenylphosphino)ferrocene (dppf) in
THF under N2 gave cis-[Pd{CH2C(O)Me}Cl(dppf)] (2) (Scheme
1) instead of the desired enolato complex that could be formed
due to the strong transphobia between C- and P-donor ligands.
Thus, the reaction of cis-[PdBr(Ar)(dpb)] (dpb ) 1,2-bis(diphe-
nylphosphino)benzene) with K{OC(dCMe2)Ph} gives the eno-
lato complex cis-[Pd(Ar){OC(dCMe2)Ph}(dpb)], although most
potassium enolates afford the corresponding 2-oxoalkyl deriva-
tives.22
system, 1H, CH2C(O), 2JHH ) 17.4 Hz), 3.61 (d, 1H, CH2, allene,
2
2JHAHB ) 1.4 Hz), 3.26 (HB, AB system, 1H, CH2CO, JHAHB
)
2
17.4 Hz), 3.25 (d, 1H, CH2, allene, JHH ) 1.4 Hz), 2.21 (s, 3H,
MeCO), 1.32 (s, 3H, Me, allene), 1.31 (s, 3H, Me, allene). 13C{1H}
NMR (50.32 MHz, CDCl3): δ 203.9 (CO), 114.9 (C), 91.4 (C),
(22) Culkin, D. A.; Hartwig, J. F. Organometallics 2004, 23, 3398.

3982 Organometallics, Vol. 27, No. 15, 2008
Vicente et al.
Scheme 2
Addition of pyridine ligands (2.1:1) to suspensions of 1 in
acetone affords complexes [Pd{CH2C(O)Me}ClL2] (L ) py (3),
t
Mepy (4), Bupy (5)) with good yields (>90%). Complexes 3
and 4 can be easily precipitated from their solutions by addition
of Et2O, but isolation of 5 required the use n-pentane as
precipitating agent. We have unsuccessfully attempted to prepare
dinuclear complexes containing bridging acetonyl ligands
such as [Pd2{CH2C(O)Me}{µ-κ2-C,O-CH2C(O)Me}(µ-Cl)Cl-
(dmso)2], which we reported previously.4 Thus, when 1 was
reacted with py, Mepy, or tBupy in 1:1 molar ratio, complexes
3-5 were obtained along with 50% of unreacted 1. CDCl3
solutions of complexes 3-5 contain an approximately 10:1
mixture of trans and cis isomers. Complex 3 reacts with Tl(acac)
in 1:1 molar ratio to give [Pd{CH2C(O)Me}(acac)(py)] (6).
Although complexes 2-6 are air stable, CDCl3 solutions of 2-5
slowly decompose to give acetone and [PdCl2L2].
Synthesis of Cationic Complexes. The room-temperature
reaction of complex 3 or 5 with TlOTf (1:1 molar ratio) in dry
acetone gives almost instantly a precipitate of TlCl. From the
filtrate, a mixture (by NMR) of products was isolated that we
could not separate. However, bands corresponding to ν(CO)
appearing at lower frequencies than in the starting complexes
suggest the formation of some complex containing a bridging
acetonyl or η3-oxoallyl ligand.
1) led to [Pd{(nbn)CH2C(O)Me}ClL2] (L2 ) bpy (11), dbbpy
(12)) (Scheme 2), although 12 could not be obtained analytically
pure. Complex 11 results from the syn insertion of the exo face
of the norbornene double bond into the Pd-Cacetonyl bond. This
is the general mode of insertion of this olefin into Pd-C bonds.25
Only a limited number of examples of alkene insertion into a
Pd-Cketonyl bond have been reported,17,26 but 11 is the first such
complex fully characterized. The behavior of 1 toward other
olefins (cyclohexene, cyclooctene, maleic anhydride, and di-
Addition of L to the suspensions resulting from addition of
TlOTf (1:1 molar ratio) in THF or acetone to complexes 3-5
led to the isolation of the corresponding cationic complexes
t
[Pd{CH2C(O)Me}L3]TfO (L ) py (7), Mepy (8), Bupy (9)).
Alternatively, reaction of 1 with Mepy or tBupy and QTfO (Q
) Tl, K, respectively) (1:3:1) also afforded complex 8 or 9,
respectively. The reaction of 9 with triphos (1:1 molar ratio) in
THF gave [Pd{CH2C(O)Me}(triphos)]TfO (10). We designed
this reaction assuming that the P/C transphobia23 induced a
change of the acetonyl ligand to the enolato coordination mode.
This has been observed in a few cases. Thus, although
1
methyl maleate) was followed by H NMR in CD3CN, but no
reaction was observed in any case after several days.
The reaction between 1 and 1,5-cyclooctadiene (cod; 1:1
molar ratio) in dry THF gave [PdCl{CH2C(O)Me}(η4-cod)] (13,
Scheme 2). When the reaction was carried out in acetone, 13
t
cis-[Pd(Ar)Br(dpb)] (Ar ) C6H4Me-2, C6H4 Bu-4; dpb ) 1,2-
1
bis(diphenylphosphino)benzene) reacts with different potassium
enolates KOC(dCRR′)R′′ to give the expected 2-oxoalkyl
complexes cis-[Pd(Ar){CRR′C(O)R′′}(dpb)], when R ) R′ )
Me and R”′′ ) Ph, the enolato isomer cis-[Pd(Ar){OC(d
CMe2)C(O)Ph}(dpb)] was obtained.22,24 The stabilization of the
enolato isomer was attributed to steric reasons, which explains
that in our case (R ) R′ ) H and R′′ ) Me) the ketonyl isomers
2 and 10 were obtained.
was obtained contaminated with an impurity. The H NMR
spectrum in CDCl3 solution of the crude product showed the
presence of [PdCl2(cod)], which could be the product of the
Reactions of 1 with Alkenes and Allenes. The reaction of
1
1 with norbornene (nbn, 1:2) was followed by H NMR in
CD3CN. After 1 h, the reaction mixture showed the absence of
complex 1. When the reaction was repeated in a preparative
scale in MeCN, a solid could be precipitated by addition of
Et2O. This solid could not be identified, but the presence of a
band at 1714 cm-1 in the IR spectra suggested the insertion of
the alkene into the Pd-Cacetonyl bond. However, the reaction of
1 with norbornene followed by addition of bpy or dbbpy (1:2:
(23) (a) Vicente, J.; Abad, J. A.; Frankland, A. D.; Ram´ırez de Arellano,
M. C. Chem.-Eur. J. 1999, 5, 3066. (b) Vicente, J.; Abad, J. A.; Herna´ndez-
Mata, F. S.; Jones, P. G. J. Am. Chem. Soc. 2002, 124, 3848. (c) Vicente,
J.; Abad, J. A.; Mart´ınez-Viviente, E.; Jones, P. G. Organometallics 2002,
21, 4454. (d) Vicente, J.; Arcas, A.; Bautista, D.; Jones, P. G. Organome-
tallics 1997, 16, 2127. (e) Vicente, J.; Arcas, A.; Ga´lvez-Lo´pez, M. D.;
Jones, P. G. Organometallics 2006, 25, 4247. (f) Jalil, M. A.; Fujinami, S.;
Nishikawa, H. J. Chem. Soc., Dalton Trans. 2001, 1091. (g) Amatore, C.;
Bahsoun, A. A.; Jutand, A.; Meyer, G.; Ntepe, A. N.; Ricard, L. J. Am.
Chem. Soc. 2003, 125, 4212. (h) Crespo, M.; Granell, J.; Solans, X.; Font-
Bardía, M. J. Organomet. Chem. 2003, 681, 143. (i) Lo´pez, C.; Caubet,
A.; Pe´rez, S.; Solans, X.; Font-Bardía, M. J. Organomet. Chem. 2003, 681,
82. (j) Marshall, W. J.; Grushin, V. V. Organometallics 2003, 22, 555.
Figure 1. Ellipsoid representation of complex 3 (50% probability).
Selected bond lengths (Å) and angles (deg): Pd-N(2) ) 2.0262(17),
Pd-N(1) ) 2.0270(17), Pd-C(1) 2.0804(19), Pd-Cl ) 2.3869(5),
O(1)-C(2) ) 1.232(3), C(1)-C(2) ) 1.460(3), C(2)-C(3) )
1.511(3), N(2)-Pd-C(1) ) 90.03(7), N(1)-Pd-C(1) ) 87.61(7),
N(2)-Pd-Cl ) 91.18(5), N(1)-Pd-Cl ) 91.17(5), N(2)-Pd-N(1)
) 177.61(6).

New Acetonyl Palladium(II) Complexes
Organometallics, Vol. 27, No. 15, 2008 3983
Figure 2. Ellipsoid representation of complex 8 (50% probability).
Selected bond lengths (Å) and angles (deg): Pd-N(31) ) 2.0269(18),
Pd-N(21) ) 2.0328(18), Pd-C(1) ) 2.056(2), Pd-N(11) )
2.1202(19), C(1)-C(2) ) 1.464(4), O(1)-C(2) ) 1.229(3),
C(2)-C(3))1.512(3),N(31)-Pd-C(1))89.60(9),N(21)-Pd-C(1)
) 90.56(9), N(31)-Pd-N(11) ) 89.83(7), N(21)-Pd-N(11) )
Figure 4. Ellipsoid representation of complex 13 (50% probability).
Selected bond lengths (Å) and angles (deg): Pd-C(1) ) 2.072(3),
Pd-C(5) ) 2.178(3), Pd-C(4) ) 2.193(3), Pd-Cl ) 2.3268(9),
Pd-C(9) ) 2.329(3), Pd-C(8) ) 2.358(3), O-C(2) ) 1.225(4),
C(1)-C(2) ) 1.467(5), C(2)-C(3) ) 1.501(5), C(4)-C(5) )
1.380(5), C(4)-C(11) ) 1.520(4), C(5)-C(6) ) 1.512(4), C(6)-C(7)
) 1.525(5), C(7)-C(8) ) 1.504(5), C(8)-C(9) ) 1.354(5),
C(9)-C(10) ) 1.499(4), C(10)-C(11) ) 1.539(5), C(1)-Pd-C(5)
) 89.66(13), C(1)-Pd-C(4)) 92.41(13), C(5)-Pd-C(4) )
36.81(12), C(1)-Pd-Cl ) 89.72(10), C(5)-Pd-C(9) ) 94.95(12),
C(4)-Pd-C(9))81.17(12),Cl-Pd-C(9))92.23(9),C(5)-Pd-C(8)
) 80.17(12), C(4)-Pd-C(8) ) 87.10(12), Cl-Pd-C(8) ) 95.09(9),
C(9)-Pd-C(8) ) 33.58(11).
89.96(7), C(2)-C(1)-Pd
)
108.20(16), O(1)-C(2)-C(1)
) 122.5(2), O(1)-C(2)-C(3) ) 119.1(2), C(1)-C(2)-C(3) )
118.5(2).
ratio) in dry THF gave a mixture of products that could not be
separated.
Addition of 1,1-dimethyl allene (dma) to a solution of 1 in
acetonitrile (1.2:1 molar ratio) led to the isolation of the
dinuclear π-allyl complex [Pd{η3-CH2C[CH2C(O)Me]CMe2}2(µ-
Cl)2] (14, Scheme 2), resulting from the insertion of the allene
intothePd-Cbond.ThereactionofMe4N[Pt{CH2C(O)Me}Cl2(η2-
C2H4)] with dma gives instead the substitution product cis-
Me4N[Pt{CH2C(O)Me}Cl2(η2-H2CdCdCMe2)].27
Crystals apparently suitable for an X-ray crystallographic
study were obtained for 14, but although the structure shown
in Scheme 2 was established, a complete crystallographic
analysis was not possible. Disorder was so severe that, despite
repeated attempts and data collection at low temperature, no
satisfactory refinement was achieved. However, the composition
and the position of the organic ligand acting as η3-allyl were
established with certainty. η3-Allyl palladium complexes have
Figure 3. Ellipsoid representation of complex 11 (50% probability).
Selected bond lengths (Å) and angles (deg): Pd(1)-C(11) )
2.043(2), Pd(1)-N(1) ) 2.0753(17), Pd(1)-N(2) ) 2.1518(18),
Pd(1)-Cl(1) ) 2.3069(12), O(1)-C(17) ) 1.210(3), C(11)-C(12)
) 1.544(3), C(11)-C(15) ) 1.571(2), C(12)-C(13) ) 1.536(3),
C(12)-C(19) ) 1.548(3), C(13)-C(14) ) 1.530(3), C(14)-C(20)
) 1.541(3), C(14)-C(15) ) 1.550(3), C(15)-C(16) ) 1.528(3),
C(16)-C(17) ) 1.510(3), C(17)-C(18) ) 1.509(3), C(19)-C(20)
) 1.554(3), C(11)-Pd(1)-N(1) ) 93.56(7), N(1)-Pd(1)-N(2) )
78.42(6), C(11)-Pd(1)-Cl(1) ) 94.36(6), N(2)-Pd(1)-Cl(1) )
93.51(5), C(12)-C(11)-C(15) ) 103.09(14), C(13)-C(12)-C(11)
) 102.64(15), C(13)-C(12)-C(19) ) 100.61(17), C(11)-C(12)-
C(19))107.15(17),C(14)-C(13)-C(12))94.74(16),C(13)-C(14)-C(20)
)102.22(17),C(13)-C(14)-C(15))101.85(15),C(20)-C(14)-C(15)
) 107.97(16), C(16)-C(15)-C(14) ) 111.82(15), C(16)-C(15)-
C(11))115.50(15),C(14)-C(15)-C(11))102.45(14),C(17)-C(16)-C(15)
)114.15(16),O(1)-C(17)-C(18))120.55(19),O(1)-C(17)-C(16)
) 122.22(18), C(18)-C(17)-C(16) ) 117.22(18), C(12)-C(19)-
C(20) ) 103.54(16), C(14)-C(20)-C(19) ) 102.70(17).
(24) Culkin, D. A.; Hartwig, J. F. J. Am. Chem. Soc. 2001, 123, 5816.
(25) (a) Zocchi, M.; Tieghi, G.; Albinati, A. J. Chem. Soc., Dalton Trans.
1973, 883. (b) Kang, M.; Sen, A. Organometallics 2004, 23, 5396. (c)
Zocchi, M.; Tieghi, G. J. Chem. Soc., Dalton Trans. 1979, 944. (d) Reddy,
K. R.; Surekha, K.; Lee, G.-H.; Peng, S.-M.; Chen, J.-T.; Liu, S.-T.
Organometallics 2001, 20, 1292. (e) Brumbaugh, J. S.; Whittle, R. R.;
Parvez, M.; Sen, A. Organometallics 1990, 9, 1735. (f) Bocelli, G.; Catellani,
M.; Ghelli, S. J. Organomet. Chem. 1993, 458, C12. (g) Tanaka, D.;
Romeril, S. P.; Myers, A. G. J. Am. Chem. Soc. 2005, 127, 10323. (h)
Catellani, M.; Mealli, C.; Motti, E.; Paoli, P.; Perez-Carreño, E.; Pregosin,
P. S. J. Am. Chem. Soc. 2002, 124, 4336. (i) Spek, A. L.; Markies, B. A.;
Kruis, D.; Boersma, J.; van Koten, G. Acta Crystallogr., Sect. C 1995, 51,
1535. (j) Vicente, J.; Abad, J. A.; Lo´pez-Sa´ez, M. J.; Fo¨rtsch, W.; Jones,
P. G. Organometallics 2004, 23, 4414.
reaction between DCl (from CDCl3) and an hydroxo complex
(the impurity?) resulting from the hydrolysis of 13. In addition,
13 slowly decomposes in chlorinated solvents to give
[PdCl2(cod)]. The reaction of 1 with norbornadiene (1:1 molar
(26) Ito, Y.; Nakatsuka, M.; Kise, N.; Saegusa, T. Tetrahedron Lett.
1980, 21, 2873.
(27) Vicente, J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Aullo´n, G.;
Bautista, D. Organometallics 2007, 26, 6155.

3984 Organometallics, Vol. 27, No. 15, 2008
Vicente et al.
Table 1. Crystallographic Data for Complexes
8
3
11
13
formula
fw
C13H15ClN2OPd
357.12
lath
C22H28F3N3O5Pd S
609.93
block
0.40 × 0.20 × 0.20
monoclinic
P21/c
C20H23ClN2OPd
449.25
block
C11H17ClOPd
307.10
block
0.21 × 0.20 × 0.17
orthorhombic
Pbca
cryst habit
cryst size (mm)
cryst system
space group
cell constants
a (Å)
0.54 × 0.30 × 0.10
0.32 × 0.22 × 0.08
triclinic
triclinic
P1
P1
8.2358(6)
8.817(2)
10.974(2)
73.534(5)
87.561(5)
63.968(5)
683.6(2)
2
14.0831(12)
11.5607(11)
16.9448(14)
90
112.467(4)
90
2549.4(4)
4
7.956(5)
9.980(5)
12.514(5)
97.255(5)
105.519(5)
103.746(5)
910.6(8)
2
8.2836(8)
13.7315(7)
19.6036(11)
90
90
90
b (Å)
c (Å)
R (deg)
ꢀ (deg)
γ (deg)
volume (Å3)
Z
2229.8(3)
8
λ (Å)
0.71073
1.735
1.541
0.71073
1.589
0.869
1240
0.71073
1.638
1.176
456
0.71073
1.830
1.868
Fcalcd (Mg m-3
)
µ(Mo KR) (mm-1
F(000)
)
356
1232
T (K)
2θmax (deg)
no. of reflns measd
no. of indep reflns
transmissions
Rint
173(2)
50
2523
2354
0.8611 and 0.4899
0.008
psi-scans
2354/136/164
0.0425
0.016
133(2)
60
39 875
7461
100(2)
52.7
10 018
3691
173(2)
50
3827
1962
0.862 and 0.700
0.029
semiempirical from equivalents
560/386
0.0910
0.0320
1.049
0.9118 and 0.7047
0.0143
semiempirical from equivalents
0/227
0.0582
0.0217
1.13
0.7418 and 0.6950
0.0307
psi-scans
88/128
0.0446
0.0232
0.84
abs corr
no. restrnts/params
Rw(F2, all reflns)
R(F, > 4σ(F))
S
1.07
0.32
max ∆F (e Å-3
)
1.11
0.33
0.40
1
been obtained by reacting alkyl,20,28 aryl,21 or acyl28 palladium
derivatives with allenes.
All attempts to react acetonitrile solutions of 1 with het-
erocumulenes (CS2 and RNdCdS) or alkynes (diphenylacety-
lene and dimethyl acetilendicarboxylate) were unsuccessful, and
the starting compounds or complex mixtures of products were
obtained.
Spectroscopic Properties. The H NMR spectra of com-
plexes show the methyl proton resonances in the wide range
1.21-2.53 ppm depending on neighboring group effects. Thus,
in 10, some of the aryl groups of the phosphine ligand cause
the maximum shielding (1.21 ppm); in trans-3-5 and 7-9, the
pyridine ligands lead to an intermediate shielding (1.72-1.78
ppm), while in cis-3, cis-4, 6, and 11-14 the lower shielding
is reached (2.07-2.53 ppm). The methylene acetonyl protons
appear as singlets in the range 2.51-3.00 for complexes 3-9
and 13. Those of complex 2 give a doublet of doublets at 2.70
ppm, and the 31P{1H} NMR spectrum consists of two doublets,
in agreement with the proposed structure. For CDCl3 solutions
Crystal Structures. The crystal structures of complexes 3
(Figure 1), 8 (Figure 2), 11 (Figure 3), and 13 (Figure 4)
have been solved. The palladium atoms are in an almost
square-planar coordination. The decreasing trans influence
of the ligands alkyl > acetonyl > olefin > chloro > pyridine
≈ bpy is shown by comparing the metal-to-donor atom bond
distances. Thus, Pd-N bond distances trans to: py or bpy in
3 or 8 (2.0269(2)-2.0328(2) Å) < chloro in 11 (2.0753(17)
Å) < acetonyl in 8 (2.1202(19) Å) < alkyl in 11 (2.1518(18)
Å); Pd-Colefin bond distances in 13 trans to: Cl (2.193(3),
2.178(3) Å) < acetonyl (2.358(3) and 2.329(3) Å); Pd-Cl
bond distances trans to: bpy in 11 (2.3069(12) Å) < olefin
in 13 (2.3268(9) Å) < acetonyl 3 (2.3869(6) Å); and Pd-CH2
of complexes 3-5, H and 13C NMR spectra, HMQC, and
1
NOESY 2D experiments reveal they are 10-12:1 mixtures of
1
trans/cis isomers. In the H NMR spectra of complex 10, the
CH2C(O) protons appear as a doublet of triplets and the 31P{1H}
NMR shows a triplet and a doublet for the P atoms trans and
cis to the acetonyl ligand, respectively. The insertion of
norbornene into the Pd-CH2 bond to give complexes 11 and
12 causes the expected deshielding in only one of the methylene
protons (3.45-3.47 ppm), while the other must be shielded by
one of the bpy rings (2.83-2.89 ppm). In complex 14, both
methylene protons are, as expected, more deshielded (3.78, 3.26
ppm) than those in the acetonyl complexes.
t
bond distances trans to: Bupy in 8 (2.056(2) Å) < olefin in
13 (2.072(3) Å) ≈ chloro (2.0804(19) Å).
The structure of 11 shows the exo insertion of norbornene
into the Pd-acetonyl bond. The CdO (1.210(3) Å) or CH2-CO
(1.510(3) Å) bond distance in 11 is slightly shorter or longer,
respectively, than in 3 [1.232(3), 1.460(3) Å, respectively], 8
[1.229(3), 1.464(4) Å, respectively], or 13 [1.225(4), 1.467(5)
Å, respectively]. In general, CdO and CH2-CO bond distances
inotheracetonylmetalcomplexesareintheranges1.209(3)-1.232(5)
and 1.475(4)-1.516(5), respectively.2–5,7 The molecules of 11
associate in dimers through a π · · · π stacking of the bpy rings
with a centroid-centroid distance of 3.450 Å.
1
The H NMR spectrum of 11 shows the nonequivalence of
the halves of the bpy ligand. 1H NOESY 2D experiments reveal
an interchange between both halves. A similar behavior has been
found in other organopalladium complexes.29,30 It has been
(29) (a) van Asselt, R.; Vrieze, K.; Elsevier, C. J. Organomet. Chem.
1994, 480, 27. (b) Gogoll, A.; Ornebro, J.; Grennberg, H.; Ba¨ckvall, J. E.
¨
J. Am. Chem. Soc. 1994, 116, 3631. (c) Markies, B. A.; Kruis, D.; Rietveld,
M. H. P.; Verkerk, K. A. N.; Boersma, J.; Kooijman, H.; Lakin, M. T.;
Spek, A. L.; van Koten, G. J. Am. Chem. Soc. 1995, 117, 5263.
(30) Delis, J. G. P.; Aubel, P. G.; Vrieze, K.; van Leeuwen, P. W. N. M.;
Veldman, N.; Spek, A. L.; van Neer, F. J. R. Organometallics 1997, 16,
2948.
(28) Ruelke, R. E.; Kliphuis, D.; Elsevier, C. J.; Fraanje, J.; Goubitz,
K.; van Leeuwen, P. W. N. M.; Vrieze, K. J. Chem.Soc., Chem. Commun.
1994, 1817.

New Acetonyl Palladium(II) Complexes
Organometallics, Vol. 27, No. 15, 2008 3985
proposed that it is due to a site exchange of the nitrogen donor
atoms. The mechanism of this process involves Pd-N bond
breaking and subsequent isomerization via a Y-shaped inter-
mediate.30 In 11, the same mechanism could explain its fluxional
behavior, although the intermediate could be a square-planar
complex due to coordination of the carbonyl group. A similar
behavior is found for complex 12. The allyl moiety in 14 shows
the syn and anti protons with a typical geminal coupling for
this compound. NOESY 2D experiments reveal a NOE between
the H anti and the Me anti. One CH2C(O) proton has a NOE
with the Me syn, and the other one has a NOE with the H syn.
This could be due to the rotational hindrance of the acetonyl
group around the C-CH2C(O) bond.
One absorption is observed in the IR spectra of complexes
2-10 and 13, in the region 1628-1650 cm-1, corresponding
to ν(CdO) in a terminal acetonyl ligand.1–5 However, the
absorption assignable to ν(CdO) in complexes 11, 12, and 14
appears where it is observed in organic ketones (1704-1714
cm-1). The difference is in agreement with the shortening
observed in the CdO distance in 11 with respect to those in 3
and 8 (see above).
energy region. The bands at 240 and 260 cm-1 in 14 can be
assigned to ν(PdCl) modes corresponding to bridging chloro
ligands.
Conclusion
We report our final illustration of the synthetic capacity of
the polymer [Pd{CH2C(O)Me}Cl]n to prepare in good yields
new types of acetonyl complexes: trans-[Pd{CH2C(O)Me}ClL2],
[Pd{CH2C(O)Me}L3]+, and [Pd{CH2C(O)Me}(O,O-acac)L]+.
Reactions with alkenes afford the adduct [Pd{CH2C(O)Me}-
Cl(cod)], the product resulting from the syn insertion of the exo
face of the norbornene double bond into the Pd-Cacetonyl bond,
[Pd{(nbn)CH2C(O)Me}ClL2], which is the first such complex
fully characterized, or the π-allyl complex [Pd{η3-CH2C-
[CH2C(O)Me]CMe2}2(µ-Cl)2] resulting from the insertion of
1,1-dimethyl allene in the Pd-Cacetonyl bond.
Acknowledgment. We thank Ministerio de Ciencia y
Tecnolog´ıa and FEDER for financial support (CTQ2004-
05396) and Prof. Peter G. Jones for provision of data
collection facilities. J.M.F.-H. acknowledges grants from
Fundacio´n Se´neca and Fundacio´n Cajamurcia.
The absorption frequency of the ν(Pd–Cl) band in the IR
spectra of chloro complexes increases as the trans influence of
the ligands decreases: acetonyl (3-5; 270-280 cm-1) >
P-donor ligand (2; 294 cm-1) > N-donor ligand (11, 12; 318
and 326 cm-1), which is in accordance with the X-ray crystal
structure data of 3 and 11 (see above). The ν(PdCl) band in 13
could not be assigned because several bands appear in the low-
Supporting Information Available: CIF files, listing of all
refined and calculated atomic coordinates, anisotropic thermal
parameters, bond length and angles for complexes 3, 8, 11, and
13. This material is available free of charge via the Internet at
http://pubs.acs.org.
OM8003288