Carbopalladation of maleate and fumarate esters and 1,1-Dimethylallene with ortho-substituted aryl palladium complexes

Article abstract of DOI:10.1021/om900957s

Dimethyl maleate and dimethyl and diethyl fumarates (RO₂CCH= CHCO₂R) have been reacted with [Pd(C₆H₄R ₀-2)Y(N∧N)] (R₀ = OH, CHO, CN, Y = Br, I, N∧N = tmeda, bpy, dtbbpy; 1:1:4.5 molar ratio) and TlOTf to afford complexes resulting from the stereoselective insertion of the olefin and coordnation to Pd of one carbonyl oxygen, giving an enantiomeric mixture of the five-membered metallacyclic complexes [Pd{k²C,O-2-[CH(CO₂R)CHCO ₂R]C₆H₄R₀}(N∧N)]OTf (R = Me, Et). From dimethyl maleate, the isolated complexes were RR/SS mixtures with R₀ = OH, N∧N = tmeda (2aOH), dtbbpy (2cOH) and N∧N = bpy, R₀ = CHO (2bCHO), CN (2bCN) and from the fumarates RS/SR mixtures with N∧N = bpy,R₀ = CHO, R= Me (3bCHO), Et (4bCHO). Complex 2bCHO reacts with RNC in a 1:1 or 1:3 molar ratio to give the complexes [Pd{2-[CH(CO₂R)CHCO₂R]C₆H₄CHO}} (CNR′)n(bpy)3-n]OTf (R = Me, n = 1, R′ = Xy (5bCHO), ^tBu = (6bCHO); n = 3, R = Xy (7bCHO), ^tBu = (8bCHO)). Similarly, the fumarate derivative 3bCHO or 4bCHO afforded the corresponding complexes where R = Me, n = 1, R′ = Xy (9bCHO), n = 3, R′ = ^tBu (l0bCHO) or R = Et, n = 3, R′ = Xy (11bCHO), ^tBu (12bCHO), respectively. 1,1-Dimethylallene reacts with [Pd(C₆H₄OH-2)I(N∧N)] to give the η³-allyl complexes [Pd{η³CH ₂C(C₆H₄OH-2)CMe₂}(N∧N)]OTf (N∧N = tmeda (13aOH), dtbbpy (13cOH)). The crystal structures of 2aOH, 4bCHO, 7bCHO, and 13aOH have been determined.

Full text of DOI:10.1021/om900957s

Organometallics 2010, 29, 409–416 409
DOI: 10.1021/om900957s
Carbopalladation of Maleate and Fumarate Esters and
1,1-Dimethylallene with Ortho-Substituted Aryl Palladium Complexes
ꢀ
Jose Vicente,* Jose Antonio Abad, and Marıa-Jose Lopez-Saez
ꢀ
ꢀ ꢀ
ꢀ
´ ´ ´
Grupo de Quımica Organometalica, Departamento de Quımica Inorganica, Facultad de Quımica,
ꢀ
Universidad de Murcia, Aptdo. 4021, E-30071 Murcia, Spain
ꢀ
Peter G. Jones
€
Institut fu€r Anorganische und Analytische Chemie, Technische Universitat Braunschweig, Postfach 3329,
38023 Braunschweig, Germany
Received November 2, 2009
Dimethyl maleate and dimethyl and diethyl fumarates (RO2CCHdCHCO2R) have been reacted with
[Pd(C6H4Ro-2)Y(N∧N)] (Ro = OH, CHO, CN, Y = Br, I, N∧N = tmeda, bpy, dtbbpy; 1:1:4.5 molar
ratio) and TlOTf to afford complexes resulting from the stereoselective insertion of the olefin and coord-
nation to Pd of one carbonyl oxygen, giving an enantiomeric mixture of the five-membered metallacyclic
complexes [Pd{κ2C,O-2-[CH(CO2R)CHCO2R]C6H4Ro}(N∧N)]OTf (R = Me, Et). From dimethyl male-
ate, the isolated complexes were RR/SS mixtures with Ro = OH, N∧N = tmeda (2aOH), dtbbpy (2cOH)
and N∧N=bpy,Ro =CHO(2bCHO),CN(2bCN) and from the fumarates RS/SR mixtures with N∧N=
bpy, Ro =CHO, R=Me(3bCHO), Et(4bCHO). Complex 2bCHO reacts with RNC in a 1:1 or 1:3 molar
ratio to give the complexes [Pd{2-[CH(CO2R)CHCO2R]C6H4CHO}}(CNR0)n(bpy)3-n]OTf (R = Me,
n = 1, R0 = Xy (5bCHO), tBu = (6bCHO); n = 3, R = Xy (7bCHO), tBu = (8bCHO)). Similarly, the
fumarate derivative 3bCHO or 4bCHO afforded the corresponding complexes where R = Me, n=1, R0 =
Xy (9bCHO), n = 3, R0 = tBu (10bCHO) or R = Et, n = 3, R0 = Xy (11bCHO), tBu (12bCHO), res-
pectively. 1,1-Dimethylallene reacts with [Pd(C6H4OH-2)I(N∧N)] to give the η3-allyl complexes [Pd{η3-
CH2C(C6H4OH-2)CMe2}(N∧N)]OTf (N∧N = tmeda (13aOH), dtbbpy (13cOH)). The crystal structures
of 2aOH, 4bCHO, 7bCHO, and 13aOH have been determined.
Introduction
substituent (Ro) with the palladium center,4-13 which fre-
quently decompose to give organic compounds.4,6,12-19
Sometimes, the above processes are steps in the catalytic syn-
thesis of some organic compounds, as has been proved, for
example, for indenols, indenones, or isocoumarins.15,20-22
In general, palladium(0)-catalyzed annulation of unsatu-
rated compounds with aryl halides bearing an Ro group
is one of the most efficient syntheses of carbo- and hetero-
cycles.22,23 We have reported the synthesis of ortho-substi-
tuted aryl palladium complexes by transmetalation, using
the corresponding mercury derivatives2,6,16,24 or oxidative
addition3,9,10,12,17,19,25-27 or ortho-metalation8,27,28 reac-
tions.
We are involved in the synthesis of ortho-substituted
aryl palladium complexes because of their remarkable re-
activity. Thus, new complexes are formed via noteworthy
rearrangement processes;1-3 insertion of unsaturated re-
agents into the C-Pd bond afford new and interest-
ing complexes resulting from the interaction of the ortho
*To whom correspondence should be addressed. E-mail: jvs1@um.es;
p.jones@tu-bs.de. WWW: http://www.um.es/gqo/.
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ꢀ
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2009 American Chemical Society
Published on Web 12/23/2009
pubs.acs.org/Organometallics

410 Organometallics, Vol. 29, No. 2, 2010
Vicente et al.
Among the reactivity studies of ortho-substituted aryl palla-
dium complexes, we have reported insertions into the Pd-C
bond of alkynes,4-6,8,10,16,17,20,29 isocyanides,8,11,16,18,26,30
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and a full paper report unprecedented processes involving
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into the Pd-C bond of ortho-palladated phenol and aniline
complexes.31 Following these studies, we report here the
attempts to expand the remarkable reactivity of these aryl
complexes (Ro = OH) toward fumarate and maleate esters
and 1,1-dimethylallene, which although behaving differently
from the other reagents (no addition reactions are observed)
also give interesting results. In view of the nonintervention in
these reactions of the Ro group OH, we have extended the
9
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Article
Organometallics, Vol. 29, No. 2, 2010 411
the β-hydrogen. Of this type are the products that we report
here resulting from the insertion of maleate and fumarate
esters into the Pd-C bond of various ortho-substituted aryl
palladium complexes. The reactions of these C,O-chelating
complexes with isocyanides lead to the cleavage of the Pd-O
bond, affording stable complexes in which the same alkyl
group containing a β-hydrogen is not now involved in a
palladacycle. A few such complexes have been isolated,
e.g. [Pd(dppe)(CH2CHRR0)X] (dppe=1,2-bis(diphenylphos-
phino)ethane, X=CH2CHRR0, SPh, R=H, R0=Ph, CH2-
Ph; R = Me, Ph)37 and a mixture of [Pd{CH(CO2Me)CH2-
C6F5}(μ-Cl)(tetrahydrothiophene)}]2 and [Pd{CH(C6F5)-
CH2CO2Me}(μ-Cl)(tetrahydrothiophene)}]2,38 but they are
unstable in solution at room temperature.
Scheme 1
Allenes insert into Pd-R bonds to give π-allyl com-
plexes10,39 that are models of intermediates in palladium-
catalyzed reactions involving allenes.40,41 We report here the
synthesis of π-allyl complexes resulting from the reaction of
ortho-palladated phenol complexes and 1,1-dimethylallene.
Results and Discussion
[Pd(C6H4Ro-2)Y(N∧N)] (Y = Br, N∧N = bpy, Ro = CHO
(1bCHO), CN (1bCN)17) with TlOTf and dimethyl maleate
(dmm) or dimethyl or diethyl fumarate (dmf, def; 1:1:4.5
molar ratio) has been studied. In both cases, complexes
resulting from the insertion of the olefin and coordina-
tion of a carbonyl oxygen to Pd, [Pd{κ2C,O-2-[CH(R)CH-
CO2R0]C6H4Ro}(N∧N)]OTf (R = CO2R0, R0 = Me, Et,
Ro = OH, CHO, CN), were obtained (Scheme 1). From the
maleate, the isolated complexes were those with R0 = Me,
Ro = OH, N∧N = tmeda (2aOH), dtbbpy (2cOH) and
N∧N = bpy, Ro = CHO (2bCHO), CN (2bCN) and from
the fumarates those with N∧N = bpy, Ro = CHO, R0=Me
(3bCHO), Et (4bCHO). All reactions took place at room
temperature, except for the synthesis of 2bCN, which
required heating at 80 °C for 4 h. These results are in contrast
with some previous studies involving palladium complexes
with these olefins. Thus, some oxidative addition reactions
of aryl halides ArX to [Pd0(η2-olefin)(P∧N)] complexes
(olefin=dmf,42 P∧N=2-(PPh2)C6H4-1-CHdNR, R=C6H4-
OMe-4, CHMe2, C6H3Me2-2,6, C6H3(CHMe2)-2,6) were
reported to afford aryl Pd(II) complexes [Pd(Ar)X(P∧N)],
which did not insert the displaced olefin. It has been reported
that [Pd{κC,N-C6H4CHdNtBu-2}(μ-Cl)]2 or methyl Pd(II)
complexes do not react with dmf43 or, respectively, with
olefins containing electron-withdrawing subtituents.44 [Pd-
(η3-allyl)(Ar)(L)] complexes react with dmm and related
olefins, promoting the reductive elimination of allylarene
derivatives through the intermediate [Pd(η3-allyl)(Ar)-
(dmm)].45 These reactions differ from ours in that replace-
ment of Br or I by TfO in our case allows the coordination of
the olefin, which is known to be an essential precondition
for the migratory insertion reaction. In fact, diethyl fuma-
rate and diethyl maleate insert into the Pd-C bond of
Insertion of Maleate and Fumarate Esters. The reaction of
the complexes [Pd(C6H3XH-2-R0-5)Y(N∧N)] (X = O, Y =
I, R0 = H, N∧N = tmeda (1aOH), dtbbpy (1cOH))12 and
ꢀ
~
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412 Organometallics, Vol. 29, No. 2, 2010
Vicente et al.
[Pd{C(O)Me}(P∧P)(NCMe)]OTf (P∧P = dppe, dppp, dppb)
because of the labile nature of the MeCN ligand. However,
the corresponding products were not isolated because they
underwent β-elimination to give unsaturated ketones.46 The
reaction of [Pd(dmf)(N∧N)] (N∧N = 1,10-phenanthroline
(L1), 1,10-phenanthroline-Me2-2,9 (L2), pyridine-CHdNR-
2-Me-6 (L3)) with Me3OBF4 has been studied. The inser-
tion products [Pd{κ2C,O-2-[CH(CO2Me)CH(Me)CO2Me}-
(N∧N)]OTf (N∧N = L1, L3) were isolated, and although a
migratory insertion mechanism was proposed, the inter-
mediate [Pd(Me)(dmf)(N∧N)]OTf (N∧N = L1, L3) was
neither observed nor isolated. Curiously, the product of
reaction with L2 was [Pd(Me)(dmf)(N∧N)(OH2)], but it does
not afford the carbopalladation product.47 The carbopalla-
dation when N∧N = L1 was stereoselective, whereas when
N∧N = L3 it was not. In our case, all reactions were stereo-
selective.
Scheme 2
Scheme 3
The structures proposed for complexes 2-4 in Scheme 1
are based on the crystal structures of 2aOH and 4bCHO and
NMR data (see below). The latter also show that these
reactions are stereoselective because they give only one pair
of enantiomers, shown by X-ray data to be RR/SS for 2aOH
and RS/SR for 4bCHO. Such selectivity can be explained by
assuming the reaction pathway shown in Scheme 2 for the
reactions with dmm and dmf. The η2 coordination of the
olefin and the migratory insertion reaction leaves a coordi-
nation vacancy at Pd, which is occupied by the carbonyl
oxygen of the CO2Me group attached to the C-Ar carbon
atom. This requires a 120° rotation around the PdC-CAr
bond, which changes the relative position of the H atoms
with respect to that in the olefin.
Complex 2bCHO reacts with RNC in a 1:1 or 1:3 molar
ratio to give the complex [Pd{2-CH(CO2R0)CHCO2R0]-
C6H4CHO}}(CNR)n(bpy)3-n]OTf (Scheme 3, R0 = Me,
t
n=1, R = Xy (5bCHO), Bu = (6bCHO); n=3, R=Xy
(7bCHO), tBu = (8bCHO)). Similarly, the fumarate deriva-
tive 3bCHO or 4bCHO afforded the corresponding com-
plexes where R0 = Me, n = 1, R = Xy (9bCHO), n = 3, R =
tBu (10bCHO) or R0 = Et, n = 3, R = Xy (11bCHO), tBu
(12bCHO), respectively. In the NMR data of complexes
5-12 only one pair of enantiomers is observed, which should
correspond to that present in their parent complexes. The
crystal structure of 7bCHO confirms this assumption.
Reactions with 1,1-Dimethylallene. Unlike some of the
previous studies on the insertion of carbodiimides, isothio-
cyanates, nitriles, and cyanamides into the Pd-C bond of
ortho-palladated phenol complexes,31 these complexes react
with allenes in the usual way. Thus, reaction of complex
1aOH or 1cOH at room temperature with Me2CdCdCH2
or TlOTf in a 1:2:1 or 1:5:1 molar ratio, respectively, gave
[Pd{η3-CH2C(C6H4OH-2)CMe2}(N∧N)]OTf (N∧N = tme-
da (13aOH), dtbbpy (13cOH)) (Scheme 4). The synthesis of
pure complex 13cOH required a great excess of the allene
(otherwise, complex mixtures were obtained) and a crystal-
lization by slow diffusion of n-hexane into a CH2Cl2 solution
of the crude reaction product, which greatly reduced the
yield (27%).
5-acetyl-2,3-dihydro-3-methylene-2-n-octylbenzofuran.41,48
Our complexes are models of one intermediate in this
catalytic reaction.
Structures of Complexes. The crystal structures of
complexes 2aOH (Figure 1), 4bCHO (Figure 2), 7bCHO
(Figure 3), and 13aOH (Figure 4) have been determined by
X-ray diffraction studies and agree with those proposed in
previous schemes.
Bond distances allow a comparison of the trans influences of
some ligands. Thus, the trans influence of alkyl . R(MeO)CdO
˚
in 2aOH (Pd-N(1) = 2.1318(17), Pd-N(2) = 2.0496(16) A) or
˚
4bCHO (Pd-N(21)=2.073(2), Pd-N(31) =2.015(2) A) and
alkyl > XyNC in 7bCHO (Pd-C(30)=2.029(3), Pd-C(20)=
It has been reported that the palladium-catalyzed reac-
tion of 2-iodo-4-acetylphenol and n-octylallene affords
˚
1.980(3), Pd-C(40)=1.977(3) A).
The packing of compounds 2aOH and 13aOH involves
hydrogen bonds from the OH group of the cation to the
triflate counterion.
(46) Dekker, G. C. P.; Elsevier, C. J.; Vrieze, K.; van Leeuwen, P. W.
N. M.; Roobeek, C. F. J. Organomet. Chem. 1992, 430, 357.
(47) Ferrara, M. L.; Giordano, F.; Orabona, I.; Panunzi, A.; Ruffo,
F. Eur. J. Inorg. Chem. 1999, 1939. De Renzi, A.; Orabona, I.; Ruffo, F.
Inorg. Chim. Acta 1997, 258, 105.
(48) Larock, R. C.; Berriospena, N. G.; Fried, C. A. J. Org. Chem.
1991, 56, 2615.

Article
Organometallics, Vol. 29, No. 2, 2010 413
Scheme 4
Figure 2. X-ray thermal ellipsoid plot of the cation of the
complex 4bCHO (50% probability), showing the atom number-
˚
ing. Selected bond lengths (A) and angles (deg): Pd-N(31) =
2.015(2), Pd-O(4) = 2.0361(17), Pd-C(1) = 2.052(2), Pd-N-
(21) = 2.073(2), O(1)-C(3) = 1.221(3), O(4)-C(6) = 1.252(3),
O(5)-C(17) = 1.200(3); N(31)-Pd-C(1) = 100.99(9), O-
(4)-Pd-C(1) = 82.31(8), N(31)-Pd-N(21) = 80.14(8), O-
(4)-Pd-N(21) = 96.67(7), C(6)-O(4)-Pd = 114.18(16).
Figure 1. X-ray thermal ellipsoid plot of the complex 2aOH
(50% probability), showing the atom numbering. Only one
position of the disordered tmeda ligand is shown. Selected bond
˚
lengths (A) and angles (deg): Pd-C(1) = 2.0494(19), Pd-N(2) =
2.0496(16), Pd-O(1) = 2.0668(12), Pd-N(1) = 2.1318(17),
O(1)-C(5) = 1.235(2), O(3)-C(3) = 1.212(2), O(5)-C(12) =
1.370(2); C(1)-Pd-N(2) = 99.24(7), C(1)-Pd-O(1) = 82.33(6),
N(2)-Pd-O(1) = 174.88(6), C(1)-Pd-N(1) = 175.41(7), N-
(2)-Pd-N(1) = 85.10(7), O(1)-Pd-N(1) = 93.21(6), C(5)-
O(1)-Pd = 110.34(11), C(2)-C(1)-Pd = 105.95(12). The intra-
˚
molecular Pd O5 distance is 2.910(2) A.
3 3 3
Spectroscopic Properties of Complexes. In the Experimental
Section the wavenumbers and assignments of some IR bands
(solid state), the data of the 1H and 13C NMR spectra and the
molar conductivities in acetone of complexes have been in-
cluded. These data are consistent with the proposed structures.
The insolubility of 2bCN prevented studies in solution.
Figure 3. X-ray thermal ellipsoid plot of the cation of the
complex 7bCHO (30% probability), showing the atom number-
ing. Selected bond lengths (A) and angles (deg): Pd-C(40) =
The 3JHH values in the dmm or fumarate H-C-C-H groups
in 2aOH (0 Hz), 2cOH (0 Hz), 29bOH (3 Hz) or 3bCHO (5.6
Hz), 4bCHO (5.7 Hz) agree with those calculated using the
Karplus equation and the value found for the H-C-C-H
dihedral angle in 2aOH (97°, 1 Hz) or that in the def derivative
4bCHO (44°, 4 Hz). The 3JHH values for their reaction products
with isocyanides 32-39 are around 11 Hz, suggesting that the
minimum repulsion between the CO2R groups is reached for
H-C-C-H dihedral angles around 180°, which indeed is the
value found in the crystal structure of 7bCHO.
˚
1.977(3), Pd-C(20) = 1.980(3), Pd-C(30) = 2.029(3), Pd-
C(1) = 2.134(3), N(2)-C(20) = 1.157(4), N(3)-C(30) =
1.148(4), N(4)-C(40) = 1.153(4), O(1)-C(2) = 1.205(4),
O(3)-C(5) = 1.200(3), O(5)-C(17) = 1.220(4); C(40)-Pd-
C(20) = 177.22(12), C(40)-Pd-C(30) = 91.04(11), C(20)-Pd-
C(30) = 91.58(11), C(40)-Pd-C(1) = 84.91(11), C(20)-Pd-
C(1) = 92.63(12), C(30)-Pd-C(1) = 170.37(11), C(20)-N(2)-
C(21) = 178.5(3), C(30)-N(3)-C(31) = 177.4(3), C(40)-N(4)-
C(41) = 173.4(3).
or o-cyano groups) afford stereospecifically C,O pallada-
cycles with two chiral centers. Ortho-palladated phenol
complexes react with 1,1-dimethylallene to afford η3-allyl
complexes.
Conclusion
The first insertions of fumarates and dimethyl maleate into
the Pd-C bond of aryl complexes (with o-hydroxy, o-formyl,

414 Organometallics, Vol. 29, No. 2, 2010
Vicente et al.
Chart 1
CH-Ar), 3.84 (s, 3 H, Me), 3.73 (s, 3 H, Me), 2.95-2.49 (m, 16 H,
Me þ CH2, tmeda), 2.39 (s, 1 H, CH-Pd). 13C{1H} NMR
(75 MHz, CDCl3): δ 192.3 (CO), 178.1 (CO), 154.4 (C1), 130.7
(C3), 129.6 (C5), 123.7 (C2), 120.1 (C4), 116.8 (C6), 64.7 (CH2),
57.7 (CH2), 55.4 (Me, CO2Me), 54.6 (CH-Ar), 53.1 (Me, tmeda),
51.4 (Me, CO2Me), 50.2 (Me, tmeda), 49.8 (Me, tmeda), 48.0
(Me, tmeda), 32.0 (CH-Pd). Single crystals suitable for an X-ray
diffraction study were obtained by slow diffusion of n-hexane
into a solution of 2aOH in acetone.
Figure 4. X-ray thermal ellipsoid plot of the complex 13aOH
(50% probability), showing the atom numbering. Selected bond
lengths (A) and angles (deg): Pd-C(8) = 2.090(3), Pd-C(7) =
2.122(2), Pd-N(2) = 2.146(2), Pd-N(1) = 2.162(2), Pd-
C(9) = 2.179(3), O(1)-C(2) = 1.354(3), C(7)-C(8) = 1.414(4),
C(7)-C(9) = 1.423(4), C(9)-C(11) = 1.510(4), C(9)-C(10) =
˚
1.517(4); C(8)-Pd-C(7)
99.94(10), C(7)-Pd-N(2) = 134.26(9), C(8)-Pd-N(1)
173.89(11), C(7)-Pd-N(1) = 139.37(9), N(2)-Pd-N(1) =
83.59(8), C(8)-Pd-C(9)
38.60(10), N(2)-Pd-C(9) = 167.86(9), N(1)-Pd-C(9)
=
39.22(10), C(8)-Pd-N(2)
=
=
[Pd{K2C,O-2-[CH(CO2Me)CH(CO2Me)]C6H4OH}(dtbbpy)]-
OTf (2cOH). 1cOH (135 mg, 0.23 mmol), t = 20 h. Color:
orange. Yield: 125 mg, 74%. Dec pt (°C): 157. ΛM (Ω-1 cm2
mol-1) = 132. Anal. Calcd for C31H37F3N2O8PdS: C, 48.92; H,
4.90; N, 3.68; S, 4.21. Found: C, 48.68; H, 5.13; N, 3.72; S, 3.89.
IR (cm-1): ν(OH) 3602, ν(CO) 1668, 1614. 1H NMR (400 MHz,
CDCl3): δ8.92 (s, 1 H, OH), 8.71 (d, 1 H, dtbbpy, 3JHH = 6.0Hz),
8.49 (d, 1 H, dtbbpy, 3JHH = 5.6 Hz), 8.00 (s, 1 H, dtbbpy), 7.99
(s, 1 H, dtbbpy), 7.68 (d, 1 H, dtbbpy, 3JHH = 5.6 Hz), 7.48 (d,
1 H, dtbbpy, 3JHH = 6.0 Hz), 7.15-7.05 (m, 3 H, C6H4), 6.79 (t,
1 H, C6H4, 3JHH = 7.3 Hz), 4.23 (s, 1 H, CH-Ar), 4.04 (s, 3 H,
Me), 3.72 (s, 3 H, Me), 2.89 (s, 1 H, CH-Pd), 1.45 (s, 9 H, tBu),
=
69.29(11), C(7)-Pd-C(9)
=
=
106.66(9), C(8)-C(7)-C(9) = 117.7(2), C(8)-C(7)-C(1) =
119.2(2), C(9)-C(7)-C(1) = 121.9(2).
Experimental Section
General Considerations. When not otherwise stated, the reac-
tions were carried out without precautions to exclude light or
atmospheric oxygen or moisture. Melting points were deter-
mined on a Reicher apparatus and are uncorrected. Elemental
analyses were carried out with a Carlo Erba 1106 microanalyzer.
IR spectra were recorded on a Perkin-Elmer 16F PC FT-IR
spectrometer with Nujol mulls between polyethylene sheets.
Molar conductivities were measured for ca. 5 ꢀ 10-4 mol L-1
acetone solutions with a Crison Micro CM2200 conductimeter.
NMR spectra were recorded in Bruker Avance 200, 300, and
400 NMR spectrometers. Some NMR assignments were per-
formed with the help of APT, COSY, HMQC, and HMBC
experiments. Chart 1 gives the atom numbering used in NMR
assignments. Ligands (tmeda, bpy, tbbp, RNC) and reagents
(dmm, fumarates, and 1,1-dimethylallene) were purchased and
t
1.43 (s, 9 H, Bu). 13C{1H} NMR (100 MHz, CDCl3): δ 194.0
(CO), 177.9 (CO), 165.7 (C, dtbbpy), 165.4 (C, dtbbpy), 156.9
(C), 154.4 (C), 152.8 (C), 152.5 (CH, dtbbpy), 148.7 (CH,
dtbbpy), 129.4 (CH, C6H4), 129.0 (CH, C6H4), 124.8 (CH,
dtbbpy), 124.3 (CH, dtbbpy), 123.6 (C), 119.8 (CH, dtbbpy þ
C6H4), 119.0 (CH, dtbbpy), 117.0 (CH, C6H4), 56.1 (Me), 52.9
(CH), 51.8 (Me), 35.9 (C, tBu), 35.7 (C, tBu), 34.3 (CH), 30.2 (Me,
tBu), 30.1 (Me, tBu).
[Pd{K2C,O-2-[CH(CO2Me)CH(CO2Me)]C6H4CN}(bpy)]OTf
(2bCN). 1bCN(100 mg, 0.23 mmol), t = 4 h. Color:yellow. Yield:
60 mg, 40%. Dec pt (°C): 196. Anal. Calcd for C24H20F3-
N3O7PdS: C, 43.82; H, 3.06; N, 6.39; S, 4.87. Found: C, 44.05;
H, 2.98; N, 6.61; S, 4.41. IR (cm-1): ν(CN) 2270, ν(CO) 1722,
1704. The insolubility of 2bCN in organic solvents prevented us
from recording its NMR spectra or determining its conductivity.
[Pd{K2C,O-2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(bpy)]OTf
(3bCHO). 1bCHO (100 mg, 0.22 mmol), t = 5 h. Color: yellow.
Yield: 107 mg, 74%. Mp (°C): 142. ΛM (Ω-1 cm2 mol-1) = 121.
Anal. Calcd for C24H21F3N2O8PdS: C, 43.62; H, 3.20; N, 4.24; S,
4.85. Found: C, 43.22; H, 3.31; N, 4.40; S, 4.78. IR (cm-1): ν(CO)
1688, 1600, 1584. 1H NMR (400 MHz, CD2Cl2): δ 10.06 (s, 1 H,
used as received. [Pd2(dba)3] dba (“Pd(dba)2”)49 was prepared
3
as reported. We have described elsewhere the synthesis of
complexes 1aOH, 1cOH,12 1bOH, and 1bCN.17 The solvents
were distilled before use.
General Method of Synthesis of Complexes. To a solution of
the corresponding complex 1 in 15 mL of CH2Cl2 (10 mL of
ClCH2CH2Cl for 2bCN) were added a 4.5:1 molar ratio excess of
the appropriate reagent (2:1 for 40aOH; 4:1 for 29bCHO,
30bCHO, 38bCHO, 39bCHO; 5:1 for 40cOH) and 1 equiv of
TlOTf. The resulting suspension was stirred for reaction time t
(given below individually) at room temperature (at 80 °C for
2bCN) and atmospheric conditions (under N2 for 2bCN and
13cOH). The suspension was filtered, the filtrate was concen-
trated to 2 mL, and 15 mL of Et2O (n-hexane for 13cOH) was
added. The solid was filtered off, washed with Et2O (or n-hexane
for 13cOH), and suction-dried.
CHO), 8.82 (d, 1 H, bpy, 3JHH =4.8 Hz), 8.60 (d, 1 H, bpy, 3JHH
=
4.3 Hz), 8.41 (m, 2 H, bpy), 8.31-8.25 (m, 2 H, bpy), 7.86 (dd, 1 H,
H6, 3JHH = 6.5 Hz, 4JHH = 1.3 Hz), 7.77 (td, 1 H, H4, 3JHH = 6.5
Hz, 4JHH = 1.3 Hz), 7.67-7.62 (m, 3 H, H5 þ bpy), 7.57 (dd, 1 H,
H3, 3JHH = 6.5 Hz, 4JHH = 1.8 Hz), 5.99 (d, 1 H, CH-Ar, 3JHH
=
5.6 Hz), 4.18 (s, 3 H, Me), 3.59 (s, 3 H, Me), 3.44 (d, 1 H, CH-Pd,
3JHH = 5.6 Hz). 13C{1H} NMR (100 MHz, CD2Cl2): δ 195.0
(CHO), 153.1 (CH, bpy), 148.9 (CH, bpy), 141.8 (CH, bpy), 141.6
(CH, bpy), 137.1 (CH, C6H4), 134.2 (CH, C6H4), 131.3 (CH, C6H4)
129.0 (CH, C6H4), 128.1 (CH, bpy), 128.1 (CH, bpy), 124.5 (CH,
bpy), 123.7 (CH, bpy), 57.2 (Me), 52.1 (CH-Ar), 50.3 (Me), 37.0
(CH-Pd).
[Pd{K2C,O-2-[CH(CO2Me)CH(CO2Me)]C6H4OH}(tmeda)]-
OTf (2aOH). 1aOH (51 mg, 0.12 mmol), t = 17 h. Color: yellow.
Yield: 47 mg, 80%. Mp (°C): 131. ΛM (Ω-1 cm2 mol-1) = 132.
Anal. Calcd for C19H29F3N2O8PdS: C, 37.48; H, 4.80; N 4.60; S,
5.27. Found: C, 37.15; H, 5.10; N, 4.61; S, 5.06. IR (cm-1):
1
ν(OH) 3258, ν(CO) 1682, 1619. H NMR (400 MHz, CDCl3):
δ 9.42 (s, 1 H, OH), 7.19 (br, 2 H, H5 þ H6), 7.00 (d,
[Pd{K2C,O-2-[CH(CO2Et)CH(CO2Et)]C6H4CHO}(bpy)]OTf
(4bCHO). 1bCHO (100 mg, 0.22 mmol), t = 5 h room tempera-
ture. Color: yellow. Yield: 127 mg, 82%. Mp (°C): 142. ΛM
(Ω-1 cm2 mol-1) = 125. Anal. Calcd for C26H25F3N2O8PdS: C,
45.34; H, 3.66; N, 4.07; S, 4.65. Found: C, 44.99; H, 3.61; N, 4.23;
3
1 H, H3, JHH = 7.3 Hz), 6.82 (m, 1 H, H4), 3.98 (s, 1 H,
(49) Takahashi, Y.; Ito, S.; Sakai, S.; Ishii, Y. J. Chem. Soc., Chem.
Commun. 1970, 1065.

Article
Organometallics, Vol. 29, No. 2, 2010 415
Table 1. Crystal Data and Structure Refinement Details for Compounds 2aOH, 4bCHO, 7bCHO, and 13aOH
1/
4bCHO 2(CH3)2CO
2aOH
7bCHO CH2Cl2
3
13aOH
3
formula
fw
C19H29F3N2O8PdS
608.90
133
monoclinic
yellow plate
0.25 ꢀ 0.25 ꢀ 0.04
P21/c
15.6847(12)
10.1913(8)
15.3249(12)
90
94.045(4)
90
C27.5H28F3N2O8.5PdS
717.98
133
C42H42Cl2F3N3O8PdS
983.15
133
C18H29F3N2O4PdS
532.89
133
monoclinic
colorless tablet
0.3 ꢀ 0.2 ꢀ 0.08
P21/c
8.4184(6)
17.7346(11)
15.4582(11)
90
105.713(4)
90
temp (K)
cryst syst
cryst habit
cryst size (mm)
space group
triclinic
triclinic
colorless prism
0.25 ꢀ 0.08 ꢀ 0.06
P1
colorless tablet
0.25 ꢀ 0.1 ꢀ 0.05
P1
˚
a (A)
9.3620(8)
11.3529(11)
14.6379(14)
99.933(4)
90.461(4)
109.265(4)
1443.1(2)
2
1.652
0.79
728
1.4 to 28.7
15210
11.2675(11)
11.8420(12)
17.0352(16)
81.832(5)
87.873(5)
76.607(5)
2188.7(4)
2
1.492
0.66
1004
1.2 to 28.6
28258
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
F
2443.5(3)
4
1.655
0.91
1240
2221.6(3)
4
1.593
0.98
1988
calcd (Mg m-3
)
μ(Mo KR) (mm-1
F(000)
)
θ range (deg)
no. of rflns coll
1.3 to 30.0
42892
1.8 to 30.5
43612
no. of indep rflns/Rint
transmissn
no. of restraints/params
goodness of fit on F2
R1 (I > 2σ(I))
7137/0.052
0.85-0.95
168/368
1.00
0.027
0.063
7290/0.047
no abs cor
44/408
0.95
0.035
0.074
0.68/-0.46
10744/0.038
0.78-0.98
0/549
0.82
0.043
0.128
1.39/-0.65
6758/0.047
0.80-0.93
2/279
1.07
0.039
0.103
5.23/-0.97
wR2 (all rflns)
largest diff peak/hole (e A
-3
˚
)
0.84/-0.39
S, 4.43. IR (cm-1): ν(CO) 1694, 1682, 1574. 1H NMR (300 MHz,
=
8.62 (br, 1 H, bpy), 8.44 (br, 2 H, bpy), 7.95 (br, 2 H, bpy), 7.87
3
3
acetone-d6): δ 10.20 (s, 1 H, CHO), 9.00 (dd, 1 H, bpy, 3JHH
(d, 1 H, C6H4, JHH = 7.5 Hz), 7.80 (d, 1 H, C6H4, JHH
7.5 Hz), 7.69 (t, 1 H, C6H4, 3JHH = 7.5 Hz), 7.54 (t, 1 H, C6H4,
3JHH = 7.5 Hz), 5.74 (s, 1 H, CH2Cl2), 5.52 (d, 1 H, CH, 3JHH
=
4
3
5.7 Hz, JHH = 1.2 Hz), 8.77 (dd, 1 H, bpy, JHH = 5.4 Hz,
4JHH = 0.9 Hz), 8.69 (d, 2 H, bpy, 3JHH = 8.1 Hz), 8.48-8.42 (m,
2 H, bpy), 8.00 (m, 1 H, C6H4), 7.96-7.85 (several m, 2 H, C6H4 þ
bpy), 7.71-7.64 (several m, 3 H, C6H4 þ bpy), 6.06 (d, 1 H,
CH-Ar, 3JHH = 5.7 Hz), 4.84-4.69 (m, 2 H, CH2), 4.13-3.97 (m,
2 H, CH2), 3.57 (d, 1 H, CH-Pd, 3JHH = 5.7 Hz), 1.42 (t, 3 H, Me,
3JHH = 7.2 Hz), 1.07 (t, 3 H, Me, 3JHH = 7.2 Hz). 13C{1H} NMR
(75 MHz, acetone-d6): δ 194.4 (CHO), 190.2 (CO), 174.0 (CO),
157.2 (C, bpy), 153.5 (C, bpy), 153.3 (CH, bpy), 148.8 (CH, bpy),
141.5 (CH, bpy), 141.4 (CH, bpy), 135.7 (C6), 135.1 (C2), 133.4
(C5), 131.1 (C3), 128.9 (C4), 127.9 (CH, bpy), 127.8 (CH, bpy),
124.2 (CH, bpy), 123.5 (CH, bpy), 67.0 (CH2), 60.0 (CH2), 49.7
(CH-Ar), 37.2 (CH-Pd), 13.5 (Me), 13.1 (Me). Single crystals
suitable for an X-ray diffraction study were obtained by slow
diffusion of n-pentane into a solution of 4bCHO in acetone.
[Pd{2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(bpy)(CNXy)]-
OTf (5bCHO). 2bCHO (90 mg, 0.14 mmol), t = 16 h. Colorless.
Yield: 93 mg, 86%. Mp (°C): 161. ΛM (Ω-1 cm2 mol-1) = 131.
Anal. Calcd for C33H30F3N3O8PdS: C, 50.05; H, 3.82; N, 5.30;
S, 4.04. Found: C, 49.73; H, 4.05; N, 5.31; S, 4.22. IR (cm-1):
=
11.0 Hz), 3.58 (d, 1 H, CH, 3JHH = 11.0 Hz), 3.46 (s, 3 H, Me),
3.32 (s, 3 H, Me), 1.73 (s, 9 H, tBu). 13C{1H} NMR (100 MHz,
dmso-d6): δ 193.2 (CHO), 175.1 (CO), 173.0 (CO), 141.7 (CH),
139.6 (C), 134.1 (CH), 133.5 (C), 133.0 (CH), 128.9 (CH), 127.9
(CH), 124.3 (CH), 60.2 (C, tBu), 52.3 (Me, CO2Me), 51.1 (Me,
CO2Me), 48.0 (CH), 28.9 (Me, tBu).
[Pd{2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(CNXy)3]OTf
(7bCHO). 2bCHO (90 mg, 0.14 mmol), t = 8.5 h. Colorless.
Yield: 115 mg, 93%. Mp (°C): 109. ΛM (Ω-1 cm2 mol-1) = 125.
Anal. Calcd for C41H40F3N3O8PdS: C, 54.83; H, 4.49; N, 4.68;
S, 3.56. Found: C, 54.55; H, 4.00; N, 4.26; S, 3.51. IR (cm-1):
ν(CN) 2204, ν(CO) 1712. 1H NMR (400 MHz, CDCl3): δ 10.02
(s, 1 H, CHO), 7.81 (d, 1 H, C6H4, 3JHH = 6.2 Hz), 7.57-7.51
(m, 2 H), 7.43-7.36 (m, 4 H), 7.26-7.22 (m, 6 H), 5.22 (d br,
1 H, CH, 3JHH = 9.0 Hz), 4.31 (d, 1 H, CH, 3JHH = 9.0 Hz),
3.68 (s, 3 H, Me, CO2Me), 3.54 (s, 3 H, Me, CO2Me), 2.56 (s, 12
H, Me, Xy), 2.48 (s, 6 H, Me, Xy). 13C{1H} NMR (100 MHz,
CDCl3): δ 193.4 (CHO), 175.3 (CO), 136.2 (C), 135.8 (C), 134.2
(CH), 133.0 (C), 131.6 (CH), 131.5 (CH), 128.7 (CH), 128.7
(CH), 128.3 (CH), 52.8 (Me, CO2Me), 51.8 (CH), 18.7 (Me, Xy),
18.59 (Me, Xy). 13C{1H} NMR (100 MHz, CDCl3, -60 °C):
δ 194.7 (CHO), 176.0 (CO), 174.3 (CO), 138.4 (C), 138.3 (CH),
135.9 (C), 135.4 (C), 134.6 (CH), 133.3 (CH), 131.6 (C), 131.5
(CH), 128.5 (CH), 128.3 (CH), 124.0 (C), 56.2 (CH), 53.0 (Me,
CO2Me), 52.0 (Me, CO2Me), 28.5 (CH), 18.8 (Me, Xy), 18.6
(Me, Xy). Single crystals suitable for an X-ray diffraction study
were obtained by slow diffusion of n-hexane into a solution of
7bCHO in CH2Cl2.
1
ν(CN) 2196, ν(CO) 1728, 1708. H NMR (200 MHz, CDCl3):
δ 10.12 (s, 1 H, CHO), 9.09 (br, 1 H, bpy), 8.79 (d, 2 H, bpy, 3JHH
= 8.0 Hz), 8.67 (br, 1 H, bpy), 8.37 (t, 2 H, bpy, 3JHH = 6.0 Hz),
7.85 (br, 1 H, bpy), 7.79 (d, 2 H, 3JHH = 8.0 Hz), 7.60 (d, 2 H,
3JHH = 4.0 Hz), 7.52-7.35 (m, 2 H), 7.29 (d, 2 H, Xy, 3JHH
=
6.0 Hz), 5.58 (d, 1 H, CH-Ar, 3JHH = 11.2 Hz), 3.80-3.60 (d br,
1 H, CH-Pd þ s, 3 H, CO2Me), 3.45 (s, 3 H, CO2Me), 2.62 (s, 6
H, Me, Xy). 13C{1H} NMR (75 MHz, CDCl3): δ 192.8 (CHO),
175.3 (CO), 173.6 (CO), 142.3 (CH), 139.1 (C), 136.2 (C), 134.4
(CH), 134.1 (CH), 133.4 (C), 131.1 (CH), 129.2 (CH),
128.6 (CH), 128.1 (CH), 125.2 (CH), 52.6 (Me), 51.6 (Me),
18.7 (Me, Xy).
[Pd{2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(CNtBu)3](OTf)
3
H2O (8bCHO H2O). 2bCHO (90 mg, 0.14 mmol), t = 1 h. The
3
[Pd{2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(bpy)(CNtBu)]
(OTf) 0.5CH2Cl2 (6bCHO 0.5CH2Cl2). 2bCHO (90 mg,
0.14 mmol), t = 4.5 h. Colorless. Yield: 93 mg, 86%. Mp
solid was heated in an oven at 70 °C for 2 h. Colorless. Yield: 88
mg, 86%. Mp (°C): 99. ΛM (Ω-1 cm2 mol-1) = 140. Anal. Calcd
for C29H42F3N3O9PdS: C, 45.11; H, 5.48; N, 5.44; S, 4.15.
Found: C, 44.83; H, 5.51; N, 5.48; S, 3.91. IR (cm-1): ν(CN)
3
3
(°C): 161. ΛM (Ω-1 cm2 mol-1) = 131. Anal. Calcd for C29.5
-
H31ClF3N3O8PdS: C, 45.05; H, 3.97; N, 5.34; S, 4.08. Found: C,
1
2230, ν(CO) 1732, 1702, 1694. H NMR (200 MHz, CDCl3):
45.35; H, 3.85; N, 5.58; S, 3.71. IR (cm-1): ν(CN) 2222, ν(CO)
δ 10.17 (s, 1 H, CHO), 7.81 (d, 1 H, C6H4, JHH = 6.0 Hz),
3
1
1714, 1698. H NMR (400 MHz, dmso-d6): δ 10.32 (s, 1 H,
7.60-7.41 (m, 3 H, C6H4), 5.25 (d br, 1 H, CH, 3JHH = 11.2 Hz),
3.87 (d, 1 H, CH, 3JHH = 11.2 Hz), 3.63 (s, 3 H, Me, CO2Me),
CHO), 9.20 (br, 1 H, bpy), 8.74 (d, 2 H, bpy, 3JHH = 7.9 Hz),

416 Organometallics, Vol. 29, No. 2, 2010
Vicente et al.
3.44 (s, 3 H, Me, CO2Me), 1.79 (s, 2 H, H2O), 1.68 (s, 18 H, tBu),
62%. Dec pt (°C): 180. ΛM (Ω-1 cm2 mol-1) = 138. Anal. Calcd for
C18H29F3N2O4PdS: C, 40.57; H, 5.49; N, 5.26; S, 6.02. Found: C,
40.36; H, 5.62; N, 5.27; S, 5.85. IR (cm-1): ν(OH) 3288. 1H NMR
(400 MHz, acetone-d6): δ 8.86 (br, 1 H, OH), 7.43 (br, 1 H, C6H4),
7.20 (td, 1 H, C6H4, 3JHH = 7.8 Hz, 4JHH = 1.7 Hz), 6.96 (d, 1 H,
t
1.63 (s, 9 H, Bu). 13C{1H} NMR (75 MHz, CDCl3): δ 193.0
(CHO), 175.5 (CO), 173.7 (CO), 140.0 (C-CHO), 134.9 (CH),
134.0 (CH), 133.3 (C-CH), 129.9 (CH), 127.9 (CH), 60.1 (C,
tBu), 60.0 (C, tBu), 52.6 (Me, CO2Me), 51.4 (Me, CO2Me), 29.9
(Me, tBu), 29.7 (Me, tBu), 29.6 (CH).
C6H4, 3JHH = 7.7 Hz), 6.87 (td, 1 H, C6H4, 3JHH = 7.8 Hz, 4JHH
=
[Pd{2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(bpy)(CNXy)]OTf
(9bCHO). 3bCHO (90 mg, 0.14 mmol), t = 1.5 h. Color: yellow.
Yield: 86 mg, 79%. Mp (°C): 93. ΛM (Ω-1 cm2 mol-1) = 124.
Anal. Calcd for C33H30F3N3O8PdS: C, 50.05; H, 3.82; N, 5.30; S,
4.04. Found: C, 49.67; H, 3.95; N, 5.48; S, 3.80. IR (cm-1): ν(CN)
2196, ν(CO) 1725, 1698. 1H NMR (400 MHz, CDCl3): δ 9.95 (s,
1.0 Hz), 3.69 (br, 1 H, allyl), 3.56 (d, 1 H, allyl, 2JHH = 1.5 Hz), 3.07
(s, 3 H, Me, tmeda), 3.04-2.95 (br, 7 H, CH2 þ Me, tmeda), 2.92 (s,
3 H, Me, tmeda), 2.67 (s, 3 H, Me, tmeda), 1.43 (s, 3 H, Me, allyl),
1.27 (s, 3 H, Me, allyl). 13C{1H} NMR (100 MHz, acetone-d6): δ
132.0 (CH), 130.3 (CH, C6H4), 123.9 (C, C6H4), 120.6 (CH, C6H4),
116.5 (CH, C6H4), 61.9 (CH2, tmeda), 60.5 (CH2, tmeda), 59.0 (br,
CH2, allyl), 52.6 (Me, tmeda), 51.3 (Me, tmeda), 50.3 (Me, tmeda),
49.5 (Me, tmeda), 23.4 (Me, allyl), 22.9 (Me, allyl). Single crystals
suitable for an X-ray diffraction study were obtained by slow
diffusion of n-pentane into a solution of 13aOH in CH2Cl2.
1 H, CHO), 8.94 (br, 1 H, bpy), 8.71 (d, 2 H, bpy, 3JHH = 8.0 Hz),
3
8.38-8.27 (m, 3 H, bpy), 7.75 (br, 1 H), 7.65 (d, 2 H, JHH
=
7.2 Hz), 7.50-7.35 (several m, 3 H), 7.28-7.16 (m, 2 H), 5.66 (br,
1H, CH), 3.74 (s, 3H, Me), 3.60(s, 3H, Me), 2.52(s,6 H, Me, Xy).
13C{1H} NMR (100 MHz, CDCl3): δ 192.5 (CHO), 176.8 (CO),
171.9 (CO), 142.4 (CH), 142.1 (CH), 140.1(C), 136.3 (C), 134.2
(CH), 133.4 (C), 131.2 (CH), 128.7 (CH), 128.4 (CH), 125.3 (CH),
52.5 (Me, CO2Me), 51.9 (Me, CO2Me), 18.7 (Me, Xy).
[Pd{η3-CH2C(C6H4OH-2)CMe2}(dtbbpy)]OTf
(13cOH).
1cOH (100 mg, 0.17 mmol), t = 14 h room temperature. An
analytically pure sample of 4 mg was obtained by slow diffusion
of n-hexane (4 mL) into a solution of 15 mg of crude product in
CH2Cl2 (1 mL). Color: orange. Yield (crude): 40 mg, 34%. Dec
pt (°C): 180. ΛM (Ω-1 cm2 mol-1) = 150. Anal. Calcd for
C30H37F3N2O4PdS: C, 52.60; H, 5.44; N, 4.09; S, 4.68. Found:
C, 52.71; H, 5.55; N, 4.06; S, 4.55. IR (cm-1): ν(OH) 3303. 1H
NMR (300 MHz, CDCl3): δ 8.79 (d, 1 H, dtbbpy, 3JHH = 5.7
Hz), 8.47 (d, 1 H, dtbbpy, 3JHH = 5.7 Hz), 8.39 (br, 1 H, OH),
8.12 (dd, 2 H, dtbbpy, 3JHH = 4.9 Hz, 4JHH = 1.7 Hz), 7.68 (m, 2
H, dtbbpy), 7.15-7.07 (m, 3 H, C6H4), 6.74 (td, 1 H, C6H4, 3JHH
= 7.1 Hz, 4JHH = 1.5 Hz), 4.07 (s, 1 H, allyl), 3.96 (s, 1 H, allyl),
1.59 (s, 3 H, Me, allyl), 1.56 (s, 3 H, Me, allyl), 1.46 (s, 18 H, tBu).
13C{1H} NMR (100 MHz, CDCl3): δ 165.3 (C, dtbbpy), 165.1
(C, dtbbpy), 155.1 (C, dtbbpy), 154.5 (C, dtbbpy), 153.8 (CH,
dtbbpy), 153.6 (C-OH), 149.4 (CH, dtbbpy), 130.1 (CH, C6H4),
129.9 (CH, C6H4), 125.0 (CH, dtbbpy), 124.7 (CH, dtbbpy),
122.2 (C, C6H4), 119.3 (CH, C6H4), 119.1 (CH, dtbbpy), 117.1
(CH, C6H4), 60.4 (CH 2), 35.8 (C, tBu), 35.8 (C, tBu), 30.3 (Me,
tBu), 24.4 (Me, allyl), 23.6 (Me, allyl).
[Pd{2-[CH(CO2Me)CH(CO2Me)]C6H4CHO}(CNtBu)3](OTf)
H2O (10bCHO H2O). 3bCHO (80 mg, 0.14 mmol), t = 8.5 h.
3
3
The solid was heated in an oven at 70 °C for 2 h. Colorless.
Yield: 61 mg, 58%. Mp (°C): 120. ΛM (Ω-1 cm2 mol-1) = 140.
Anal. Calcd for C29H42F3N3O9PdS: C, 45.11; H, 5.48; N, 5.44;
S, 4.15. Found: C, 45.31; H, 5.57; N, 5.56; S, 3.73. IR (cm-1):
ν(CN) 2226, ν(CO) 1750, 1720, 1705. 1H NMR (400 MHz,
CDCl3): δ 10.24 (s, 1 H, CHO), 7.94 (m, 1 H, C6H4), 7.61 (m, 2
H, C6H4), 7.44 (m, 1 H, C6H4), 5.49 (br, 1 H, CH), 4.01 (d, 1 H,
CH, 3JHH = 12.0 Hz), 3.69 (s, 3 H, Me, CO2Me), 3.61 (s, 3 H, Me,
CO2Me), 1.62 (s, 18 H, tBu), 1.54 (s, 9H, tBu). 13C{1H} NMR (75
MHz, CDCl3): δ 193.2 (CHO), 177.0 (CO), 172.8 (CO), 140.1 (C-
CH), 135.6 (CH, C6H4), 134.1 (CH, C6H4), 133.3 (C-CHO), 128.5
(CH, C6H4), 60.2 (C, tBu), 59.9 (C, tBu), 52.3 (Me, CO2Me), 51.6
(Me, CO2Me), 29.7 (Me, tBu), 29.6 (Me, tBu).
[Pd{2-[CH(CO2Et)CH(CO2Et)]C6H4CHO}(CNXy)3]OTf
(11bCHO). 4bCHO (100 mg, 0.15 mmol), t = 2 h. Color:
pale yellow. Yield: 100 mg, 73%. Mp (°C): 96. ΛM (Ω-1 cm2
mol-1) = 142. Anal. Calcd for C43H43F3N3O8PdS: C, 55.76; H,
4.79; N, 4.54; S, 3.46. Found: C, 55.40; H, 5.01; N, 4.60; S, 3.72.
IR (cm-1): ν(CN) 2198, ν(CO) 1733, 1710, 1694. 1H NMR
(300 MHz, CDCl3): δ 10.24 (s, 1 H, CHO), 7.96 (dd, 1 H, C6H4,
3JHH = 7.5 Hz), 7.57-7.47 (m, 2 H, C6H4), 7.42-7.28 (m, 4 H,
C6H4 þ Xy), 7.26-7.13 (m, 6 H, Xy), 5.67 (d br, 1 H, CH,
3JHH = 10.0 Hz), 4.41 (d, 1 H, CH, 3JHH = 10.0 Hz), 4.17-4.02
(m, 4 H, CH2), 2.49 (s, 12 H, Me, Xy), 2.35 (s, 6 H, Me, Xy), 1.29
(t, 3 H, Me, CO2Et), 1.14 (t, 3 H, Me, CO2Et). 13C{1H} NMR
(75 MHz, CDCl3): δ 193.3 (CHO), 176.3 (CO), 171.8 (CO),
140.3 (C-CH), 136.2 (C), 135.8 (C), 135.5 (CH, C6H4), 134.1
(CH, C6H4), 133.7 (C-CHO), 131.6 (CH, C6H4), 128.7, (CH,
C6H4), 61.3 (CH2), 60.7 (CH2), 32.7 (CH), 18.6 (Me, Xy), 18.6
(Me, Xy), 14.3 (Me, CO2Et), 13.9 (Me, CO2Et).
X-ray Structure Determinations. Intensities were registered at
low temperature on a Bruker SMART 1000 CCD diffracto-
meter using monochromated Mo KR radiation (λ = 0.710 73
˚
A). Absorption corrections were based on indexed faces for
2aOH and 13aOH and for 7bCHO on multiscans (program
SADABS);50 4bCHO was not corrected. Structures were refined
anisotropically using SHELXL-97.51 Hydrogen atoms were
included using rigid methyl groups or a riding model, except
for H of NH, OH, and allyl CH2 groups, which were refined
freely but in some cases with X-H distance restraints. Special
features and exceptions: for 2aOH, the carbons of the tmeda
ligand are disordered over two alternative positions. For
4bCHO the acetone is disordered over an inversion center; its
hydrogens were not located. For 13aOH, large difference peaks
are observed close to the Pd atoms (5.2 e A-3); these cannot be
˚
[Pd{2-[CH(CO2Et)CH(CO2Et)]C6H4CHO}(CNtBu)3]OTf
(12bCHO). 4bCHO (100 mg, 0.15 mmol), t = 45 min. Color-
less. Yield: 85 mg, 73%. Mp (°C): 70. ΛM (Ω-1 cm2 mol-1) =
119. Anal. Calcd for C31H44F3N3O8PdS: C, 47.61; H, 5.67;
N, 5.37; S, 4.10. Found: C, 47.75; H, 5.50; N, 5.30; S, 4.22. IR
(cm-1): ν(CN) 2226, ν(CO) 1722, 1698. 1H NMR (300 MHz,
CDCl3): δ 10.27 (s, 1 H, CHO), 7.94-7.90 (m, 1 H, C6H4),
7.64-7.56 (m, 2 H, C6H4), 7.48-7.44 (m, 1 H, C6H4), 5.40 (d
br, 1 H, CH, 3JHH = 10.2 Hz), 4.17-3.98 (m, 4 H, CH2), 1.54
interpreted except as possible disorder, twinning, or absorption
artifacts. Crystal data and details of the structure refinement for
all four compounds are given in Table 1.
Acknowledgment. We thank the Ministerio de
ꢀ
Educacion y Ciencia (Spain), FEDER (CTQ2007-60808/
ꢀ
ꢀ
BQU), and Fundacion Seneca (04539/GERM/06 and
03059/PI/05) for financial support. M.-J.L.-S. is grateful
to the MEC for a grant.
t
t
(s, 18 H, Bu), 1.48 (s, 9 H, Bu), 1.30 (t, 3 H, Me, CO2Et,
3
3JHH = 6.9 Hz), 1.12 (t, 3 H, Me, CO2Et, JHH = 7.2 Hz).
Supporting Information Available: Tables and CIF files giving
all refined and calculated atomic coordinates, anisotropic thermal
parameters, bond lengths and angles, and other crystallographic data
for compounds 2aOH, 4bCHO, 7bCHO, and13aOH. This material
is available free of charge via the Internet at http://pubs.acs.org.
13C{1H} NMR (75 MHz, CDCl3): δ 192.9 (CHO), 176.4
(CO), 172.2 (CO), 140.5 (C-CH), 135.1 (CH), 134.1 (CH),
133.5 (C-CHO), 128.9 (CH, C6H4), 128.4, (CH, C6H4), 61.1
(CH2), 60.3 (CH2), 30.5 (CH), 29.8 (Me, tBu), 29.6 (Me, tBu),
14.4 (Me, CO2Et), 13.9 (Me, CO2Et).
[Pd{η3-CH2C(C6H4OH-2)CMe2}(tmeda)]OTf (13aOH). 1aOH
(100 mg, 0.23 mmol), t = 18 h. Color: pale orange. Yield: 76 mg,
(50) SADABS (Version 2.0); Bruker AXS Inc., Madison, WI, 1998.
(51) Sheldrick, G. M. Acta Crystallogr., Sect. A 2008, 64, 112.