Substituent effects on P-C reductive elimination from styrylpalladium(II) phosphine complexes

Article abstract of DOI:10.1021/om100476z

A series of styrylpalladium phosphine complexes, trans-[Pd(CH=CHAr) Br(PMeAr′₂)₂] (1: Ar = Ph, 4-MeOC₆H ₄, 4-MeC₆H₄, 4-F₃CC ₆H₄, 4-O₂NC₆H₄; Ar′ = Ph, 4-MeC₆H₄, 4-FC₆H₄), have been prepared, and their P-C reductive elimination in the presence of added PMeAr′₂ (1-4 equiv) in CD₂Cl₂ has been examined by kinetic experiments. All complexes are converted to [Pd(η²-ArCH=CHPMeAr′₂)(PMeAr′₂) ₂]Br (3) at 40 °C in high selectivity. The kinetic data are consistent with the reaction process involving prior association of 1 with PMeAr′₂ to form a five-coordinate intermediate, trans-[Pd(CH=CHAr)Br(PMeAr′₂)₃] (A), which subsequently undergoes P-C reductive elimination to give 3. The pseudo-first-order rate constant (k_obsd) increases as the amount of added PMeAr′₂ ([PMeAr′₂]) increases, according to the equation 1/k_obsd = 1/kK[PMeAr′₂] + 1/k, where K = [A]/[1][PMeAr′₂] and k stands for the rate constant for the conversion of A to 3. The association constant K and the rate constant k exhibit a good Hammett correlation with the σ_p values of para substituents on the Ar and Ar′ groups, respectively: log(K _Y/K_H) = [+0.84(3)]σ_p + 0.02(1) (for Ar groups); log(K_Y/K_H) = [+4.2(4)]Σ_p + 0.09(7) (for Ar′ groups); log(k_Y/k_H) = [-2.43(9)]σ_p + 0.01(3) (for Ar groups); [-4.8(4)] Σ_p-0.11(8) (for Ar′ groups). Thus, the K value increases as the electron-withdrawing ability of para substituents increases, while the k value increases as the electron-donating ability of para substituents increases. The P-C reductive elimination mechanism from A to 3 is discussed.

Full text of DOI:10.1021/om100476z

5570 Organometallics 2010, 29, 5570–5578
DOI: 10.1021/om100476z
Substituent Effects on P-C Reductive Elimination from
Styrylpalladium(II) Phosphine Complexes†
Masayuki Wakioka and Fumiyuki Ozawa*
International Research Center for Elements Science (IRCELS), Institute for Chemical Research,
Kyoto University, Uji, Kyoto 611-0011, Japan
Received May 16, 2010
A series of styrylpalladium phosphine complexes, trans-[Pd(CHdCHAr)Br(PMeAr02)2] (1: Ar =
Ph, 4-MeOC6H4, 4-MeC6H4, 4-F3CC6H4, 4-O2NC6H4; Ar0 = Ph, 4-MeC6H4, 4-FC6H4), have been
prepared, and their P-C reductive elimination in the presence of added PMeAr02 (1-4 equiv) in
CD2Cl2 has been examined 0 by kinetic experiments. All complexes are converted to [Pd(η2-
ArCHdCHPMeAr02)(PMeAr 2)2]Br (3) at 40 °C in high selectivity. The kinetic data are consistent
with the reaction process involving prior association of 1 with PMeAr02 to form a five-coordinate
intermediate, trans-[Pd(CHdCHAr)Br(PMeAr02)3] (A), which subsequently undergoes P-C reduc-
tive elimination to give 3. The pseudo-first-order rate constant (kobsd) increases as the amount
of added PMeAr02 ([PMeAr02]) increases, according to the equation 1/kobsd = 1/kK[PMeAr02] þ 1/k,
where K = [A]/[1][PMeAr02] and k stands for the rate constant for the conversion of A to 3. The asso-
ciation constant K and the rate constant k exhibit a good Hammett correlation with the σp values of
para substituents on the Ar and Ar0 groups, respectively: log(KY/KH) = [þ0.84(3)]σp þ 0.02(1) (for
P
Ar groups); log(KY/KH) = [þ4.2(4)] σp þ 0.09(7) (for Ar0 groups); log(kY/kH) = [-2.43(9)]σp þ
P
0.01(3) (for Ar groups); [-4.8(4)] σp - 0.11(8) (for Ar0 groups). Thus, the K value increases as the
electron-withdrawing ability of para substituents increases, while the k value increases as the
electron-donating ability of para substituents increases. The P-C reductive elimination mechanism
from A to 3 is discussed.
Introduction
performance of polymeric materials.6 Accordingly, mecha-
nistic information about the P-C reductive elimination is of
particular importance for developing efficient catalysis. In
this context, the mechanism of Ar/Ar0 group exchange on
[PdAr0(X)(PAr3)2] complexes has been examined by Novak
et al. and later by Grushin.3b,c They found a strong retarda-
tion effect of added tertiary phosphine ligand and proposed a
dissociative pathway of P-C reductive elimination.
Palladium-catalyzed organic transformations are among
the most widely used synthetic reactions, and many of them
involve a tertiary phosphine coordinated organopalladium
complex of the formula [PdR(X)(PAr3)2] (R = alkyl, aryl,
alkenyl; X=halide, pseudohalide) as a key intermediate.1 It
has been documented that this type of complex often under-
goes P-C reductive elimination to give phosphonium ha-
lides and Pd(0) species.2 This process is usually reversible
with P-C oxidative addition of phosphonium salts to Pd(0)
species, and the overall process results in intramolecular
exchange of the palladium-bound R group with the Ar group
of phosphine ligands.3-5 The R/Ar group exchange lowers
the chemical yield and selectivity of catalytic reactions.
Particularly in polycondensation reactions based on cross-
coupling processes, the R/Ar group exchange causes struc-
tural defects in polymer chains and, thus, deteriorating
Recently, we examined P-C reductive elimination from
trans-[Pd(CHdCHPh)Br(PMePh2)2] (1a).7,8 This reaction
(2) (a) Huang, C.-C.; Duan, J.-P.; Wu, M.-Y.; Liao, F.-L.; Wang,
S.-L.; Cheng, C.-H. Organometallics 1998, 17, 676. (b) Rybin, L. V.;
Petrovskaya, E. A.; Rubinskaya, M. I.; Kuz'mina, L. G.; Struchkov, Y. T.;
Kaverin, V. V.; Koneva, N. Y. J. Organomet. Chem. 1985, 288, 119. (c)
Migita, T.; Shimizu, T.; Asami, Y.; Shiobara, J.; Kato, Y.; Kosugi, M. Bull.
Chem. Soc. Jpn. 1980, 53, 1385. (d) Migita, T.; Nagai, T.; Kiuchi, K.;
Kosugi, M. Bull. Chem. Soc. Jpn. 1983, 56, 2869. (e) Kowalski, M. H.;
Hinkle, R. J.; Stang, P. J. J. Org. Chem. 1989, 54, 2783. (f ) Hinkle, R. J.;
Stang, P. J.; Kowalski, M. H. J. Org. Chem. 1990, 55, 5033. (g) Clark, J. H.;
Tavener, S. J.; Barlow, S. J. J. Mater. Chem. 1995, 5, 827. (h) Vicente, J.;
Abad, J.-A.; Frankland, A. D.; De Arellano, M. C. R. Chem. Eur. J. 1999, 5,
3066. (i) Dervisi, A.; Edwards, P. G.; Newman, P. D.; Tooze, R. P. Dalton
2000, 523. ( j) Bourgogne, C.; Le, F. Y.; Juen, P.; Masson, P.; Nicoud, J.-F.;
Masse, R. Chem. Mater. 2000, 12, 1025. (k) Arisawa, M.; Yamaguchi, M.
J. Am. Chem. Soc. 2000, 122, 2387. (l) Arisawa, M.; Yamaguchi, M. Adv.
Synth. Catal. 2001, 343, 27. (m) de la Torre, G.; Gouloumis, A.; Vazquez, P.;
Torres, T. Angew. Chem., Int. Ed. 2001, 40, 2895. (n) Jutand, A.; Negri, S.
Organometallics 2003, 22, 4229. (o) Cheng, Z.; Subbarayan, M.; Chen, X.;
Gambhir, S. S. J. Label. Compd. Radiopharm. 2005, 48, 131. (p) Arisawa,
M.; Yamaguchi, M. J. Am. Chem. Soc. 2006, 128, 50. (q) Marcoux, D.;
Charette, A. B. J. Org. Chem. 2008, 73, 590.
† Part of the Dietmar Seyferth Festschrift. Dedicated to Professor Dietmar
Seyferth in honor of his outstanding service as Editor-in-Chief of Organo-
metallics.
*To whom correspondence should be addressed. E-mail: ozawa@scl.
kyoto-u.ac.jp.
(1) (a) Tsuji, J. Palladium in Organic Synthesis; Springer: Berlin,
Germany, 2005. (b) Tsuji, J. Palladium Reagents and Catalysts: New
Perspectives for the 21st Century; Wiley: Chichester, U.K., 2004. (c)
Hegedus, L. S.; Soderberg, B. C. G. Transition Metals in the Synthesis of
Complex Organic Molecules, 3rd ed.; University Science Books: Sausalito,
€
CA, 2009.
r
pubs.acs.org/Organometallics
Published on Web 06/10/2010
2010 American Chemical Society

Article
Organometallics, Vol. 29, No. 21, 2010 5571
Scheme 1
Scheme 2
[Pd(η2-PhCHdCHPMePh2)(PMePh2)2]Br (3a) is afforded
instead of 2a.
To gain further insight into the P-C reductive elimination
process, we compared in this study the reaction rates of styryl
complexes 1a-g, having a series of para substituents with
different electronic properties on Ar and Ar0 groups (Scheme 2).
It has been found that electron-donating substituents on both
the styryl and phosphine ligands accelerate the P-C reductive
elimination to a great extent.10,11
serves as the initiation process for homocoupling of (E )-
styryl bromide to give 1,4-diphenylbutadiene.9 The P-C
reductive elimination of arylpalladium complexes is a rever-
sible process that involves a difficulty in analyzing the
mechanism. In contrast, the P-C reductive elimination
from 1a proceeds irreversibly to form the corresponding
η2-styrylphosphonium complex in high selectivity. Thus,
we carried out a detailed mechanistic investigation using
kinetic techniques. Scheme 1 illustrates the experimental
observations. Complex 1a (Ar, Ar0 = Ph) follows two reac-
tion courses, depending on the amount of PMePh2 added to
the system. In the absence of added PMePh2, dissociative
path (a), giving [Pd(η2-PhCHdCHPMePh2)Br(PMePh2)]
(2a), is operative. On the other hand, since this process
involves rate-determining dissociation of PMePh2 ligand
from 1a, the reaction course dramatically changes to asso-
ciative path (b) in the presence of added PMePh2, where
Results
Preparation of trans-[Pd(CHdCHAr)Br(PMeAr02)2] (1).
The styryl complexes were prepared by oxidative addition of
(E )-ArCHdCHBr (1-4 equiv) to palladium(0) complexes
generated in situ from [Pd(η5-C5H5)(η3-C3H5)] and PMeAr02
(2.05 equiv) in toluene (for 1a,c-g) orEt2O(for1b) (Scheme2).
The complexes were isolated as pale yellow crystals in high
yields (70-97%) and identified by NMR spectroscopy and
elemental analysis.12
Selected 13C{1H} and 31P{1H} NMR data are given in
Table 1. The complexes exhibit a singlet signal in the 31P{1H}
NMR spectra, consistent with the square-planar geometry
around the palladium having two PMeAr02 ligands in mu-
tually trans positions. The variation in the chemical shifts is
quite small, and no notable dependence on substituents is
observed (δ 7.9 ( 0.6). The β-carbon signals of styryl ligands
are apparently insensitive to substituents as well. On the
other hand, the 13C NMR signals of R-carbons adjacent to
palladium tend to be shifted upfield as the electron-donating
ability of the substituents on the styryl ligands increases.13
The chemical shifts are linearly correlated with the Hammett
σp values:14 δC=[15(1)]σp þ 145.4(6) (Figure 1).
(3) (a) Kong, K.-C.; Cheng, C.-H. J. Am. Chem. Soc. 1991, 113, 6313.
(b) Goodson, F. E.; Wallow, T. I.; Novak, B. M. J. Am. Chem. Soc. 1997,
119, 12441. (c) Grushin, V. V. Organometallics 2000, 19, 1888. (d)
€
Herrmann, W. A.; Brossmer, C.; Priermeier, T.; Oefele, K. J. Organomet.
Chem. 1994, 481, 97. (e) Segelstein, B. E.; Bulter, T. W.; Chenard, B. L.
J. Org. Chem. 1995, 60, 12. (f ) Sakamoto, M.; Shimizu, I.; Yamamoto, A.
Chem. Lett. 1995, 1101. (g) Vicente, J.; Abad, J.-A.; Martinez-Viviente, E.;
Ramirez de Arellano, M. C.; Jones, P. G. Organometallics 2000, 19, 752. (h)
Kwong, F. Y.; Chan, K. S. Organometallics 2000, 19, 2058. (i) Hwang, L. K.;
Na, Y.; Lee, J.; Do, Y.; Chang, S. Angew. Chem., Int. Ed. 2005, 44, 6166. ( j)
€
Schn€urch, M.; Hammerle, J.; Mihovilovic, M. D.; Stanetty, P. Synthesis
2010, 837.
(4) An alternative mechanism involving a phosphido intermediate
has been proposed for the conversion of trans-[PdMe(I)(PPh3)2] to
[PdPh(I)(PMePh2)(PPh3)]: Morita, D. K.; Stille, J. K.; Norton, J. R.
J. Am. Chem. Soc. 1995, 117, 8576.
P-C Reductive Elimination from 1. As described in the
Introduction the P-C reductive elimination of 1a follows
either a dissociative or an associative path, depending on the
amount of added PMePh2. Since the rate-determining step of
(5) For a review, see: Macgregor, S. A. Chem. Soc. Rev. 2007, 36, 67.
(6) (a) Wallow, T. I.; Novak, B. M. J. Org. Chem. 1994, 59, 5034. (b)
Frahn, J.; Karakaya, B.; Schafer, A.; Schluter, A.-D. Tetrahedron 1997, 53,
15459. (c) Goodson, F. E.; Hartwig, J. F. Macromolecules 1998, 31, 1700. (d)
Goodson, F. E.; Wallow, T. I.; Novak, B. M. Macromolecules 1998, 31, 2047.
(e) Remmers, M.; Mueller, B.; Martin, K.; Raeder, H.-J.; Koehler, W.
Macromolecules 1999, 32, 1073. (f ) Goodson, F. E.; Hauck, S. I.; Hartwig,
J. F. J. Am. Chem. Soc. 1999, 121, 7527. (g) Banerjee, S.; Maier, G.; Burger,
M. Macromolecules 1999, 32, 4279. (h) Jayakannan, M.; van Dongen,
J. L. J.; Janssen, R. A. J. Macromolecules 2001, 34, 5386. (i) Jayakannan, M.;
Lou, X.; Van Dongen, J. L. J.; Janssen, R. A. J. J. Polym. Sci., Part A:
Polym. Chem. 2005, 43, 1454. ( j) Murage, J.; Eddy, J. W.; Zimbalist, J. R.;
McIntyre, T. B.; Wagner, Z. R.; Goodson, F. E. Macromolecules 2008, 41,
7330.
(7) Wakioka, M.; Nakajima, Y.; Ozawa, F. Organometallics 2009, 28,
2527.
(8) The P-C reductive elimination of a styrylpalladium complex has
been reported for trans-[Pd(CHdCHPh)Br(PPh3)2].2a
(9) Wakioka, M.; Nagao, M.; Ozawa, F. Organometallics 2008, 27,
602.
(10) Substituent effects on C-C, C-N, C-O, and C-S reductive
elimination from [PdAr0(Y)L2] type complexes (Y = aryl, amido,
alkoxo, thiolato; L = tertiary phosphine ligand) have been reviewed:
Hartwig, J. F. Inorg. Chem. 2007, 46, 1936.
(11) For a general discussion of reductive elimination mechanisms,
see: Ozawa, F. In Current Methods in Inorganic Chemistry; Yamamoto,
A., Kurosawa, H., Eds.; Elsevier Science: Amsterdam, The Netherlands,
2003; Vol. 3 (Fundamentals of Molecular Catalysis), Chapter 9.
(12) The X-ray structure of 1a was previously reported.7
(13) The assignments of the R- and β-carbons of alkenyl ligands are
based on H,C-HSQC experiments. The chemical shifts are comparable
to those of trans-[Pd(CHdCHPh)(NHPh)(PMe3)2]: Villanueva, L. A.;
Abboud, K. A.; Boncella, J. M. Organometallics 1994, 13, 3921.
(14) Inamoto, N. Hammett Soku (Rule); Maruzen: Tokyo, Japan, 1983.

5572 Organometallics, Vol. 29, No. 21, 2010
Table 1. 13C{1H} and 31P{1H} NMR Data for trans-[Pd(CHdCHAr)Br(PMeAr02)2] (1)a
13C NMR: δ (ppm) [JPC (Hz)]
Wakioka and Ozawa
complex
31P NMR: δ (ppm)
Ar
Ar0
PdCHdCHAr
PdCHdCHAr
PMeAr02
1a
1b
1c
1d
1e
1f
Ph
4-MeOC6H4
4-MeC6H4
4-F3CC6H4
4-O2NC6H4
4-O2NC6H4
4-O2NC6H4
Ph
Ph
Ph
Ph
Ph
145.4 (t) [8]
141.4 (t) [7]
143.5 (t) [8]
151.4 (t) [8]
157.8 (t) [9]
159.1 (t) [8]
157.2 (t) [8]
133.9 (t) [6]
132.7 (t) [6]
133.7 (t) [6]
132.7 (t) [6]
132.3 (t) [6]
132.0 (t) [6]
133.9 (t) [6]
8.0 (s)
7.8 (s)
7.6 (s)
8.4 (s)
8.5 (s)
7.4 (s)
8.0 (s)
4-MeC6H4
4-FC6H4
1g
a Measured in CD2Cl2 at -20 °C.
Figure 1. Dependence of the chemical shifts of R-vinylic car-
bons in 1a-g on the σp values of para substituents on the Ar
groups. The straight line is based on least-squares calculations
(r = 0.986).
Scheme 3
Figure 2. 31P{1H} NMR spectra of the reaction solutions of
P-C reductive elimination from 1b in the presence of (a) 1 equiv
and (b) 4 equiv of added PMePh2 in CD2Cl2 at -20 °C.
(parts a and b, respectively). In addition to small signals due
to 4b (δ 19.4) and phosphine oxide (δ 29.2), spectrum a
exhibits three sets of signals at δ 21.2 (d, 3JPP=12 Hz), 4.2 (d,
2JPP = 4 Hz), and 3.9 (dd, 3JPP=12 Hz, 2JPP=4 Hz) in the
same intensity; they are assigned to styrylphosphonium and
two PMePh2 ligands in 3b, respectively. As seen from spect-
rum b, complex 3b is preserved as the main product in the
presence of 4 equiv of added PMePh2, though the amount of
4b increases and two additional broad signals due to [Pd-
(PMePh2)n] and free PMePh2 are observed at δ -3.6 and
-26.8, respectively. Thus, highly selective P-C reductive
elimination takes place in the presence of added PMePh2.
Because the isolation of 3a-g was unfeasible due to poor
the latter path is assignable to P-C reductive elimination
from a five-coordinate intermediate,7 we examined the ef-
fects of para substituents on this path.
Complexes 1a-g underwent P-C reductive elimination in
the presence of added PMeAr02 (1-4 equiv/Pd) in CD2Cl2 at
40 °C to give the corresponding styrylphosphonium com-
plexes [Pd(η2-ArCHdCHPMeAr02)(PMeAr02)2]Br (3a-g),
together with small amounts of styrylphosphonium salts
[ArCHdCHPMeAr02]Br (4a-g), which are formed by sub-
sequent displacement of the styrylphosphonium ligands in
3a-g with PMeAr02 (Scheme 3).
1
crystallinity,15 these species were characterized by H and
13C{1H} NMR spectroscopy. In the 13C{1H} NMR spectra,
the R- and β-carbon signals of styrylphosphonium ligands
were observed at δ 33-34 and 63-65, respectively. Both of
these carbon atoms exhibited P-C couplings with the two
PMeAr02 ligands (30-34 and 5-7 Hz), showing π-coordination
Figure 2 shows 31P{1H} NMR spectra of the reaction
solutions after the completion of P-C reductive elimination
from 1b in the presence of 1 and 4 equiv of added PMePh2
(15) Most of the complexes were obtained as oily materials that we
were unable to obtain in an analytically pure form.

Article
Organometallics, Vol. 29, No. 21, 2010 5573
Table 2. P-C Reductive Elimination from trans-[Pd-
(CHdCHAr)Br(PMeAr02)2] (1)a
[PMeAr02]0
(mM)
data
range (%)c
product ratio
(3/4)
run complex
104kobsd (s-1 b
)
1
2
3
4
5
6
7
8
1a
1a
1a
1a
1b
1b
1b
1b
1c
1c
1c
1c
1d
1d
1d
1e
1e
1e
1f
50
64
100
200
50
0.76(2)
0.87(1)
1.28(2)
2.14(1)
2.96(4)
3.67(5)
5.26(5)
9.20(7)
1.40(1)
1.54(1)
2.29(1)
4.39(3)
0.0847(8)
0.0898(8)
0.125(1)
0.0303(4)
0.0364(5)
0.0399(2)
0.0794(6)
0.0995(8)
0.149(9)
0.264(1)
0.0092(1)
0.0095(2)
0.0103(1)
19
29
38
60
35
37
53
74
55
78
82
88
25
51
61
20
16
43
21
27
41
57
22
15
30
99/1
98/2
96/4
94/6
99/1
98/2
94/6
86/14
97/3
96/4
98/2
92/8
98/2
97/3
94/6
99/1
97/3
95/5
95/5
96/4
95/5
96/4
96/4
96/4
95/5
65
100
200
50
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
58
100
200
50
58
100
50
73
91
50
63
96
188
50
Figure 3. Plots of 1/kobsd against 1/[PMePh2] for the kinetic
data in Table 2 for 1a-c. The straight lines are based on least-
squares calculations: 1/kobsd = [5.7(4)] ꢁ 102 s M/[PMePh2] þ
[2.1(5)] ꢁ 103 s (for 1a, r = 0.995); [1.52(3)] ꢁ 102 s M/[PMePh2] þ
[3.4(4)] ꢁ 102 s (for 1b, r = 0.999); [3.2(2)] ꢁ 102 s M/[PMePh2] þ
[8(3)] ꢁ 102 s (for 1c, r = 0.994).
1f
1f
1f
1g
1g
1g
62
109
Figures 3 and 4 show the plots of 1/kobsd against 1/
[PMeAr02] for 1a-c and 1d-g, respectively. Applying the
slope and intercept values of each plot to eq 2 results in the
equilibrium (K ) and rate constants (k ) given in Table 3. It is
seen that the equilibrium constant (K ) increases as the
electron-withdrawing ability of para substituents on the Ar
and Ar0 groups increases. In contrast, the rate constant for
P-C reductive elimination (k ) increases to a great extent as
the electron-donating ability of para substituents increases.
Each series of kinetic parameters showed a good Hammett
correlation with the σp values of substituents (Figures 5 and 6).
a [1]0 = 50 mM. All reactions were examined by 1H NMR spectros-
copy using 1,3,5-trimethoxybenzene as an internal standard. b The
numbers in parentheses are standard deviations derived from least-
squares calculations. c The upper range of the conversion of 1, taken into
the first-order plot.
of the styrylphosphonium ligands with the Pd(PMeAr02)2
moiety. The R-carbon atoms also showed a large P-C
coupling with the phosphonium moiety (77-80 Hz).
Kinetic Examinations. The reductive elimination reactions
of 1a-g were followed by 1H NMR spectroscopy using 1,3,5-
trimethoxybenzene as an internal standard. Table 2 sum-
marizes the results. All kinetic runs were performed in
CD2Cl2 at 40 °C in the presence of 1-4 equiv/1 of added
PMeAr02. Under these conditions, since the concentration of
free PMeAr02 gradually decreases with the formation of 3,
the reaction rate changes with the reaction progress. Accord-
ingly, the rate constants (kobsd) were estimated in most cases
from the early stages of the time-conversion curves for 1; the
upper ranges of conversion taken into the kinetic analysis are
given in the table. In this situation, the P-C reductive elimi-
nation could be treated as a pseudo-first-order reaction with
respect to the concentration of 1 (r > 0.999).
As seen from Table 2, the reaction rate increases with
increasing amounts of added PMeAr02. This tendency is con-
sistent with the associative path (b) in Scheme 1, which consists
of a rapid interconversion between 1 and A and the rate-
determining formation of 3. The reaction rate is expressed by
eq 1, and the kobsd value is correlated with the concentration
of added PMeAr02 by eq 2, where [Pd-styryl] = [1] þ [A], K =
[A]/[1][PMeAr02], and k stands for the rate constant for the
conversion of A to 3.
Discussion
The opposite electronic effects of para substituents on the
K and k values have been observed. It is reasonable that a
more electron-withdrawing substitute provides a more elec-
tron-deficient palladium center with a higher affinity for
phosphine ligand and therefore leads to a larger association
constant (K ).
There are two possible processes for the conversion of A to
3 (Scheme 4). One is the stepwise process (a) involving a
metallophosphorane intermediate (B), and the other is the
direct process (b) with concurrent formation of the P-CHd
CHAr and Pd-(η2-CHdCHAr) bonds. Recently, Macgregor
et al. compared closely related processes for F/Ph exchange on
[RhF(PPh3)3] to afford [RhPh(PFPh2)(PPh3)2] using DFT
calculations. They found the former as an energetically favor-
able process.16,17 We assume a similar process (i.e., process a in
Scheme 4) for the following reasons. (1) Although there is a
possibility that process b becomes advantageous over process a
due to the π-coordination ability of the styrylphosphonium
ligand being higher than that of the phenylphosphonium ligand
d½3ꢀ
dt
d½Pd-styrylꢀ
dt
kK½PMeAr02ꢀ
¼ -
¼
½Pd-styrylꢀ ð1Þ
ð2Þ
1 þ K½PMeAr02ꢀ
(16) Macgregor, S. A.; Roe, D. C.; Marshall, W. J.; Bloch, K. M.;
Bakhmutov, V. I.; Grushin, V. V. J. Am. Chem. Soc. 2005, 127, 15304.
(17) For reviews of metallophosphorane, see: Goodman, J.; Macgregor,
S. A. Coord. Chem. Rev. 2010, 254, 1295. Nakazawa, H.; Kubo, K.; Miyoshi, K.
Bull. Chem. Soc. Jpn. 2001, 74, 2255. Dillon, K. B. Chem. Rev. 1994, 94, 1441.
Montgomery, C. D. Phosphorus, Sulfur, Silicon Relat. Elem. 1993, 84, 23.
1
¼
1
1
þ
kobsd
kK½PMeAr02ꢀ
k

5574 Organometallics, Vol. 29, No. 21, 2010
Wakioka and Ozawa
Figure 4. Plots of 1/kobsd against 1/[PMeAr02] for the kinetic
data in Table 2 for 1d-g. The straight lines are based on least-
squares calculations: 1/kobsd = [3.9(4)] ꢁ 103 s M/[PMePh2] þ
[4.1(6)] ꢁ 104 s (for 1d, r = 0.994); [8.80(2)] ꢁ 103 s M/[PMePh2] þ
[1.539(4)] ꢁ 105 s (for 1e, r = 0.999); [6.00(7)] ꢁ 103 s M/[PMe-
(C6H4Me)2] þ [5.3(9)] ꢁ 103 s (for 1f, r = 0.999); [1.08(7)] ꢁ 104 s
M/[PMe(C6H4F)2] þ [8.7(1)] ꢁ 105 s (for 1g, r = 0.997).
Figure 5. Hammett plots for equilibrium constants (K) in
Table 3 against the σp (for 1a-e) or σp (for 1e-g) values
P
of para substituents on the Ar and Ar0 groups. log(KY/KH) =
[þ0.84(3)]σp þ 0.02(1) (for Ar, r = 0.998); log(KY/KH) =
P
[þ4.2(4)] σp þ 0.09(7) (for Ar0, r = 0.996).
Table 3. Equilibrium (K) and Rate (k) Constants for Reductive
Elimination from trans-[Pd(CHdCHAr)Br(PMeAr02)2] (1)a
complex
Ar (σp)b
Ar0 (σp)b
K (M-1) 106k (s-1
)
1a
1b
1c
1d
1e
1f
Ph (0)
Ph (0)
3.6
2.2
3
11
17.5
0.88
81
480
2900
1000
24
6.50
200
1.1
4-MeOC6H4 (-0.27) Ph (0)
4-MeC6H4 (-0.17) Ph (0)
4-F3CC6H4 (þ0.54) Ph (0)
4-O2NC6H4 (þ0.78) Ph (0)
4-O2NC6H4 (þ0.78) 4-MeC6H4 (-0.17)
4-O2NC6H4 (þ0.78) 4-FC6H4 (þ0.06)
1g
a Conditions: [1]0 = 50 mM, [PMeAr02]0 = 50-200 mM, in CD2Cl2 at
40 °C. b The Hammett parameters of para substituents on the Ar and Ar0
groups, taken from ref 14.
(i.e., [PhPFPh2]þ in the rhodium system), the observed sub-
stituent effects are apparently inconsistent with this assumption.
(2) The previous DFT calculations revealed that the phos-
phorus atom that undergoes P-C reductive elimination is
significantly positively charged after the reaction.9 If the positive
charge continuously increases during the reaction, and the
phosphorus atom in B is more electron-deficient than that in
A,18 the metallophosphorane intermediate (B) would be stabi-
lized to a considerable extent by electron-donating substituents,
and thereby the reductive elimination would be accelerated.
Thus, the kinetic data are consistent with process a, while it is
difficult to completely exclude process b at the present stage.
Electronic substituent effects on the reductive elimination
of two reactive ligands from a Pd(II) center have been studied
for the last several decades, and they are categorized into
two classes, depending on the sort and combination of the
ligands.10,11 In general, for symmetrical complexes having the
same reactive ligands, a donating-donating combination of
substituents leads to a higher reaction rate, as typically ob-
served for dialkyl complexes.11 On the other hand, reductive
Figure 6. Hammett plots for the rate constants (k) in Table 3
against the σp (for 1a-e) or σp (for 1e-g) values of para sub-
P
stituents on the Ar and Ar0 groups. log(kY/kH) = [-2.43(9)]σp þ
P
0.01(3) (for Ar, r = 0.997); [-4.8(4)] σp - 0.11(8) (for Ar0, r =
0.996).
elimination from unsymmetrical complexes tends to be
facilitated by the combination of electron-withdrawing and
electron-donating substituents. This type of substituent ef-
fect has been documented mainly for arylpalladium com-
plexes of the formula [PdAr0(Y)L2] (Y = aryl, alkyl, amido,
alkoxo, thiolato; L = tertiary phosphine ligand),10,19 where an
electron-withdrawing para substituent on the Ar0 group en-
hances the reductive elimination rate to a considerable extent.
An interesting feature found in those systems is the major
contribution of the resonance effect (rather than the inductive
effect) of para substituents, which is consistent with the so-
called “migratory reductive elimination” process involving the
(18) Continuous growth in the positive change of phosphorus atom
has been suggested by DFT calculations for a related reaction involving
a metallophosphorane intermediate: Erhardt, S.; Macgregor, S. A.
J. Am. Chem. Soc. 2008, 130, 15490.
(19) For the substituent effects on aryl(alkyl)palladium(II) complexes,
see: Ozawa, F.; Kurihara, K.; Fujimori, M.; Hidaka, T.; Toyoshima, T.;
Yamamoto, A. Organometallics 1989, 8, 180.

Article
Organometallics, Vol. 29, No. 21, 2010 5575
a
Scheme 4
to the literature.21 Diarylmethylphosphines (PMeAr02: Ar0 =
4-MeC6H4, 4-FC6H4) were prepared by methylation of the
22
corresponding PClAr02 with MeLi in Et2O.23 (E )-(2-Bromo-
ethenyl)arenes,24 except for styryl bromide, were prepared
from benzaldehyde derivatives by the procedure reported for
(E,E )-bis(2-bromoethenyl)arenes.25 All other chemicals were
obtained from commercial suppliers and used without further
purification.
Preparation of trans-[Pd(CHdCHC6H4OMe)(PMePh2)2]
(1b). This complex was synthesized similarly to 1a.9 To a
homogeneous solution of [Pd(η5-C5H5)(η3-C3H5)] (106 mg,
0.500 mmol) in Et2O (4.0 mL) was added PMePh2 (210 mg,
1.05 mmol) at 0 °C. The mixture was stirred for 10 min, and a
solution of (E )-4-(2-bromoethenyl)anisole (107 mg, 0.500
mmol) in Et2O (2.0 mL) was added at 0 °C. The homogeneous
solution was stirred at room temperature for 5 h and then
allowed to stand at -20 °C to afford pale yellow crystals of
1b, which was analytically pure (349 mg, 97% yield). Complexes
1c-g were similarly prepared using toluene instead of Et2O as a
reaction solvent and isolated as analytically pure samples by
recrystallization of powdery products from CH2Cl2/pentane
(for 1c) or CH2Cl2/Et2O (for 1d-g) at -20 °C. The identifica-
tion data are as follows. The NMR data for 1a, which were
reexamined under the same conditions for comparison, are
included.
a L = PMeAr02.
intramolecular nucleophilic attack of the Y group at the ipso
carbon atom of the Ar0 ligand.11,20 Thus, the participation of the
π orbital on the ipso carbon is of particular importance for the
Ar0-Y bond formation. On the other hand, while the present
P-C reductive elimination is categorized into the unsymme-
trical type, the contribution of π orbitals to the P-C bond
formation would be much smaller than that in the Ar0-Y bond
formation. In this case, the electron-donating para substituents
on the ArCHdCH and PMeAr02 ligands weaken the Pd-ligand
bonds and thereby destabilize the ground state. Furthermore,
the electron-donating substituents very probably stabilize the
metallophosphorane intermediate (B) as described above, and
the overall effects of substituents enhance the P-C reductive
elimination reaction.
1a: 1H NMR (CD2Cl2, -20 °C) δ 7.61-7.55 and 7.46-7.35
(m, 20H in total), 7.00 (t, 3JHH = 7.6 Hz, 2H), 6.93 (t, 3JHH
=
7.2 Hz, 1H), 6.50 (dt, 3JHH = 16.0 Hz, 3JHP = 9.5 Hz, 1H), 6.43
3
3
(d, JHH = 7.3 Hz, 2H), 5.58 (d, JHH = 16.0 Hz, 1H), 2.04
(virtual triplet, Japp = 3.3 Hz, 6H); 13C{1H} NMR (CD2Cl2,
-20 °C) δ 145.4 (t, 2JPC=8 Hz), 139.6 (s), 133.9 (t, 3JPC = 6 Hz),
133.3 (virtual triplet, Japp = 6 Hz), 133.0 (virtual triplet, Japp
=
23 Hz), 130.3 (s), 128.6 (virtual triplet, Japp=5 Hz), 128.1 (s),
125.4 (s), 124.8 (s), 14.5 (virtual triplet, Japp=16 Hz); 31P{1H}
NMR (CD2Cl2, -20 °C) δ 8.0 (s).
1b: 97% yield; mp 72-74 °C dec; 1H NMR (CD2Cl2, -20 °C)
δ 7.62-7.55 and 7.46-7.35 (m, 20H in total), 6.55 (d, 3JHH
=
Conclusion
8.7 Hz, 2H), 6.36 (d, 3JHH = 8.7 Hz, 2H), 6.24 (dt, 3JHH = 15.9
Hz, 3JHP = 9.7 Hz, 1H), 5.49 (dt, 3JHH = 15.9 Hz, 4JHP = 1.9
Hz, 1H), 3.66 (s, 3H), 2.04 (virtual triplet, Japp = 3.3 Hz, 6H);
13C{1H} NMR (CD2Cl2, -20 °C) δ 157.1 (s), 141.4 (t, 2JPC = 7
Hz), 133.1 (virtual triplet, Japp = 6 Hz), 132.8 (virtual triplet,
We have succeeded in kinetic observations of substituent
effects on the P-C reductive elimination from trans-[Pd-
(CHdCHAr)Br(PMeAr02)2] (1) to give [Pd(η2-ArCHd
CHPMeAr02)(PMeAr02)2]Br (3) via the five-coordinate inter-
mediate [Pd(CHdCHAr)Br(PMeAr02)3] (A). With respect to
both of the Ar and Ar0 groups, more electron-withdrawing
para substituents facilitate the association of 1 with PMeAr02
to give A. However, since the P-C reductive elimination
from A to give 3 is accelerated by electron-donating substit-
uents to a notable extent, the overall process is facilitated by
electron-donating substituents. These observations are in
accordance with the P-C reductive elimination process
involving a metallophosphorane intermediate (B).
J
app = 23 Hz), 132.6 (s), 132.7 (t, 3JPC = 6 Hz), 130.2 (s), 128.4
(virtual triplet, Japp = 5 Hz), 125.6 (s), 112.9 (s), 55.1 (s), 14.2
(virtual triplet, Japp = 16 Hz); 31P{1H} NMR (CD2Cl2, -20 °C)
δ 7.8 (s). Anal. Calcd for C35H35BrOP2Pd: C, 58.39; H, 4.90.
Found: C, 58.67; H, 4.95.
1c: 71% yield; mp 80-82 °C dec; 1H NMR (CD2Cl2, -20 °C)
δ 7.61-7.55 and 7.45-7.35 (m, 20H in total), 6.82 (d, 3JHH
=
8.0 Hz, 2H), 6.40 (dt, 3JHH = 15.9 Hz, 3JHP = 9.6 Hz, 1H), 6.34
(d, 3JHH = 8.0 Hz, 2H), 5.53 (d, 3JHH = 15.9 Hz, 1H), 2.16 (s,
3H), 2.02 (virtual triplet, Japp = 3.3 Hz, 6H); 13C{1H} NMR
(CD2Cl2, -20 °C) δ 143.5 (t, 2JPC = 8 Hz), 136.9 (s), 135.0 (s),
133.7 (t, 3JPC = 6 Hz), 133.3 (virtual triplet, Japp = 6 Hz), 133.1
(virtual triplet, Japp = 23 Hz), 130.3 (s), 128.7 (s), 128.5 (virtual
triplet, Japp = 5 Hz), 124.7 (s), 21.0 (s), 14.5 (virtual triplet,
Experimental Section
General Considerations. All manipulations were carried out
under a nitrogen atmosphere using standard Schlenk techni-
ques. Nitrogen was dried by passing through P2O5 (Merck,
SICAPENT). NMR spectra were recorded on a Bruker Avance
400 spectrometer (1H NMR 400.13 MHz, 13C NMR 100.62
MHz, and 31P NMR 161.97 MHz). Chemical shifts are reported
in δ (ppm), referenced to the 1H (residual protons) and 13C
signals of deuterated solvents or to the 31P signal of an external
85% H3PO4 standard. Elemental analysis was performed by the
ICR Analytical Laboratory, Kyoto University. CD2Cl2 was
dried over CaH2, distilled, and stored over activated MS4A.
The complex [Pd(η5-C5H5)(η3-C3H5)] was prepared according
J
app = 16 Hz); 31P{1H} NMR (CD2Cl2, -20 °C) δ 7.6 (s). Anal.
Calcd for C35H35BrP2Pd: C, 59.72; H, 5.01. Found: C, 59.76; H,
5.05.
(21) Tatsuno, Y.; Yoshida, T.; Otsuka, S. Inorg. Synth. 1979, 19, 220.
(22) Casalnuovo, A. L.; RajanBabu, T. V.; Ayers, T. A.; Warren,
T. H. J. Am. Chem. Soc. 1994, 116, 9869.
(23) Seyferth, D.; Burlitch, J. M. J. Org. Chem. 1963, 28, 2463.
(24) (E )-4-(2-Bromoethenyl)anisole, (E )-4-(2-bromoethenyl)toluene:
Bull, J. A.; Mousseau, J. J.; Charette, A. B. Org. Lett. 2008, 10, 5485.
(E)-1-(2-Bromoethenyl)-4-(trifluoromethyl)benzene, (E)-1-(2-bromoethenyl)-
4-nitrobenzene: Haack, R. A.; Penning, T. D.; Djuric, S. W.; Dziuba, J. A.
Tetrahedron Lett. 1988, 29, 2783.
(20) Calhorda, M. J.; Brown, J. M.; Cooley, N. A. Organometallics
1991, 10, 1431.
(25) Wakioka, M.; Mutoh, Y.; Takita, R.; Ozawa, F. Bull. Chem. Soc.
Jpn. 2009, 82, 1292.

5576 Organometallics, Vol. 29, No. 21, 2010
Wakioka and Ozawa
1d: 85% yield; mp 118-120 °C dec; 1H NMR (CD2Cl2,
-20 °C) δ 7.60-7.53 and 7.45-7.35 (m, 20H in total), 7.23 (d,
3JHH = 8.2 Hz, 2H), 6.74 (dt, 3JHH = 16.1 Hz, 3JHP = 9.3 Hz,
1H), 6.45 (d, 3JHH = 8.2 Hz, 2H), 5.62 (d, 3JHH = 16.1 Hz, 1H),
2.08 (virtual triplet, Japp = 3.3 Hz, 6H); 13C{1H} NMR (CD2-
(dd, 1JPC = 31 Hz, 3JPC = 3 Hz), 136.0 (dd, 1JPC = 31 Hz, 3JPC
1 Hz), 134.2 (d, 4JPC = 3 Hz), 134.1 (d, 4JPC = 3 Hz), 133.5 (dd,
1JPC = 33 Hz, 3JPC = 2 Hz), 132.8 (d, 2JPC = 10 Hz), 132.3 (d,
2JPC = 10 Hz), 132.2 (d, 2JPC = 15 Hz), 132.0 (d, 2JPC = 14 Hz),
131.2 (d, 2JPC = 14 Hz), 130.6 (d, 2JPC = 13 Hz), 130.4 (m), 129.9
(m), 129.9 (m), 129.9 (d, 3JPC = 12 Hz), 129.7 (d, 3JPC = 12 Hz),
129.2 (m), 129.0 (d, 3JPC = 9 Hz), 129.0 (d, 3JPC = 9 Hz), 128.8
(br), 128.4 (d, JPC = 9 Hz), 128.4 (d, JPC = 9 Hz), 125.7 (s),
124.6 (s), 124.5 (dd, 1JPC = 89 Hz, 4JPC = 2 Hz), 123.8 (dd, 1JPC
= 82 Hz, 4JPC = 6 Hz), 65.3 (dd, 2JPC = 31 Hz, 2JPC = 6 Hz),
33.3 (ddd, 1JPC = 79 Hz, 2JPC = 31 Hz, 2JPC = 7 Hz), 14.3 (d,
2JPC = 19 Hz), 12.1 (d, 2JPC = 20 Hz), 11.3 (d, 2JPC = 64 Hz);
31P{1H} NMR (CD2Cl2, -20 °C) δ 21.6 (d, 3JPP = 12 Hz), 4.5 (s),
4.3 (d, 3JPP = 12 Hz).
=
2
Cl2, -20 °C) δ 151.4 (t, JPC=8 Hz), 142.6 (s), 133.3 (virtual
triplet, Japp = 6 Hz), 132.8 (virtual triplet, Japp = 23 Hz), 132.7
3
3
3
(t, JPC = 6 Hz), 130.4 (s), 128.6 (virtual triplet, Japp=5 Hz),
126.3 (q, 2JFC = 32 Hz), 124.9 (q, 3JFC=4 Hz), 124.8 (s), 124.8
(q, 1JFC=273 Hz), 14.5 (virtual triplet, Japp=16 Hz); 31P{1H}
NMR (CD2Cl2, -20 °C) δ 8.4 (s). Anal. Calcd for C35H32-
BrF3P2Pd: C, 55.47; H, 4.26. Found: C, 55.45; H, 4.31.
1e: 92% yield; mp 106-108 °C dec; 1H NMR (CD2Cl2,
3
-20 °C) δ 7.82 (d, JHH = 8.8 Hz, 2H), 7.58-7.52 and 7.43-
3b: 1H NMR (CD2Cl2, -20 °C) δ 7.82-7.76, 7.70-7.63,
7.62-7.56, 7.52-7.20, 7.14-7.07 (m, 26H in total), 6.66 (d,
3JHH = 8.7 Hz, 2H), 6.58-6.48 (m, 6H), 3.76 (s, 3H), 3.63-3.49
(m, 2H), 1.84 (d, 2JHP = 13.1 Hz, 3H), 1.53 (d, 2JHP = 5.2 Hz,
3H), 1.05(d, 2JHP =6.0Hz, 3H);13C{1H} NMR (CD2Cl2, -20 °C)
δ 158.0 (d, 4JPC = 2 Hz), 138.4 (dd, 1JPC = 28 Hz, 3JPC = 4 Hz),
137.3 (dd, 1JPC = 30 Hz, 3JPC = 3 Hz), 136.3 (dd, 1JPC = 31 Hz,
3JPC = 1 Hz), 134.2 (d, 4JPC = 3 Hz), 134.0 (dd, 1JPC = 31 Hz,
3JPC = 2 Hz), 134.0 (d, 4JPC = 3 Hz), 133.9 (dd, 3JPC = 12Hz, 3JPC
= 6 Hz), 132.9 (d, 2JPC =10 Hz), 132.5(d, 2JPC =10 Hz), 132.2 (d,
2JPC = 15 Hz), 131.9 (d, 2JPC = 14 Hz), 131.3 (d, 2JPC = 14 Hz),
130.7 (d, 2JPC = 13 Hz), 130.3 (m), 129.9 (d, 2JPC = 12 Hz), 129.8
7.33 (m, 20H in total), 6.99 (dt, 3JHH = 16.2 Hz, 3JHP = 9.1 Hz,
1H), 6.40 (d, 3JHH = 8.8 Hz, 2H), 5.69 (d, 3JHH = 16.2 Hz, 1H),
2.12 (virtual triplet, Japp=3.3 Hz, 6H); 13C{1H} NMR (CD2-
Cl2, -20 °C) δ 157.8 (t, 2JPC=9 Hz), 145.0 (s), 144.7 (s), 133.2
(virtual triplet, J = 6 Hz), 132.6 (virtual triplet, Japp=23 Hz),
132.3 (t, 3JPC = 6 Hz), 130.5 (s), 128.7 (virtual triplet, Japp=5
Hz), 124.9 (s), 123.6 (s), 14.4 (virtual triplet, Japp = 16 Hz);
31P{1H} NMR (CD2Cl2, -20 °C) δ 8.5 (s). Anal. Calcd for
C34H32BrNO2P2Pd: C, 55.57; H, 4.39; N, 1.91. Found: C, 55.54;
H, 4.25; N, 1.95.
1f: 73% yield; mp 93-95 °C dec; 1H NMR (CD2Cl2, -20 °C)
δ 7.83 (d, 3JHH = 8.9 Hz, 2H), 7.41 (dt, 3JHH = 7.7 Hz, 3JHP
=
(m), 129.8 (m), 129.6 (d, 2JPC = 12 Hz), 129.2 (m), 129.0 (d, 3JPC
=
5.4 Hz, 8H), 7.16 (d, 3JHH = 7.7 Hz, 8 H), 7.03 (dt, 3JHH = 16.2
Hz, 3JHP = 9.0 Hz, 1H), 6.42 (d, 3JHH = 8.9 Hz, 2H), 5.66 (dt,
9 Hz), 129.0 (d, 3JPC = 9 Hz), 128.4 (d, 3JPC = 9 Hz), 128.4 (d,
3JPC = 9 Hz), 125.8 (s), 124.6 (dd, 1JPC = 89 Hz, 4JPC = 2 Hz),
124.0 (dd, 1JPC =82Hz, 4JPC = 6 Hz), 114.0 (s), 65.4 (dd, 2JPC =31
Hz, 2JPC =5Hz), 33.1 (ddd, 1JPC = 79 Hz, 2JPC = 30 Hz, 2JPC = 7
3JHH = 16.2 Hz, 1H), 2.31 (s, 12H), 2.06 (virtual triplet, Japp
3.4 Hz, 6H); 13C{1H} NMR (CD2Cl2, -20 °C) δ 159.1 (t, 2JPC
=
=
8 Hz), 145.1 (s), 144.6 (s), 140.8 (s), 133.1 (virtual triplet, Japp=6
Hz), 132.0 (t, 3JPC = 6 Hz), 129.4 (virtual triplet, Japp = 24 Hz),
129.3 (virtual triplet, Japp = 5 Hz), 124.8 (s), 123.6 (s), 21.5 (s),
14.4 (virtual triplet, Japp = 16 Hz); 31P{1H} NMR (CD2Cl2,
-20 °C) δ 7.2 (s). Anal. Calcd for C38H40BrNO2P2Pd: C, 57.70;
H, 5.10; N, 1.77. Found: C, 57.37; H, 5.29; N, 1.79.
Hz), 14.4 (d, 2JPC = 19 Hz), 12.3 (d, 2JPC = 20 Hz), 11.3 (d, 2JPC
=
64 Hz); 31P{1H} NMR (CD2Cl2, -20 °C) δ 21.2 (d, 3JPP = 12 Hz),
4.2 (d, 2JPP = 4 Hz), 3.9 (dd, 3JPP = 12 Hz, 2JPP = 4 Hz).
3c: 1H NMR (CD2Cl2, -20 °C) δ 7.82-7.76, 7.70-7.58,
7.57-7.56, 7.51-7.20, 7.12-7.06 (m, 26H in total), 6.93 (d,
3JHH = 7.9 Hz, 2H), 6.52-6.43 (m, 6H), 3.62-3.43 (m, 2H),
1.85 (d, 2JHP = 13.1 Hz, 3H), 1.53 (d, 2JHP = 5.4 Hz, 3H), 1.03
1g: 70% yield; mp 113-115 °C dec; 1HNMR(CD2Cl2, -20 °C)
δ 7.89 (d, 3JHH = 8.6 Hz, 2H), 7.58-7.50 (m, 8H), 7.08 (dd, 3JFH
= 8.5 Hz, 3JHH = 8.5 Hz, 8H), 7.02 (dt, 3JHH = 16.2 Hz, 3JHP
=
(d, JHP = 6.1 Hz, 3H); 13C{1H} NMR (CD2Cl2, -20 °C) δ
2
9.0 Hz, 1H), 6.58 (d, 3JHH = 8.7 Hz, 2H), 5.72 (d, 3JHH = 16.2 Hz,
1H), 2.07 (virtual triplet, Japp=3.1 Hz, 6H); 13C{1H} NMR (CD2-
Cl2, -20 °C) δ 164.1 (d, 1JFC = 251 Hz), 157.3 (t, 2JPC = 8 Hz),
145.0 (s), 144.6 (s), 135.4 (doublet of virtual triplet, 3JFC = 8 Hz,
138.6 (dd, 3JPC = 12 Hz, 3JPC = 6 Hz), 138.3 (dd, 1JPC=29 Hz,
3JPC=3 Hz), 137.2 (dd, 1JPC = 31 Hz, 3JPC = 3 Hz), 136.2 (d,
1JPC = 32 Hz), 135.0 (d, 4JPC = 3 Hz), 134.2 (d, 4JPC = 3 Hz),
134.1 (d, 4JPC=3 Hz), 133.8 (dd, 1JP2C=33 Hz, 4JPC = 2 Hz),
2
J
app=7 Hz), 132.4(t, 3JPC=6 Hz), 128.2(virtual triplet of doublet,
132.8 (d, JPC = 10 Hz), 132.4 (d, JPC = 10 Hz), 132.2 (d,
Japp = 24 Hz, 4JFC = 4 Hz), 124.8 (s), 123.9 (s), 116.0 (doublet of
virtual triplets, 2JFC = 21 Hz, Japp = 6 Hz), 14.7 (virtual triplet,
2JPC = 15 Hz), 131.9 (d, 2JPC = 14 Hz), 131.2 (d, 2JPC=14 Hz),
2
2
130.7 (d, JPC = 13 Hz), 130.3 (m), 129.9 (d, JPC = 12 Hz),
129.9 (m), 129.6 (d, 2JPC = 12 Hz), 129.5 (s), 129.2 (m), 129.0 (d,
3JPC = 9 Hz), 129.0 (d, 3JPC = 9 Hz), 128.4 (d, 3JPC = 10 Hz),
J
app=16 Hz); 31P{1H} NMR (CD2Cl2, -20 °C) δ 8.0 (s). Anal.
Calcd for C34H28BrF4NO2P2Pd: C, 50.61; H, 3.50; N, 1.74.
Found: C, 50.66; H, 3.56; N, 1.75.
128.3 (d, 3JPC = 9 Hz), 124.5 (s), 124.1 (d, 1JPC = 88 Hz, 4JPC
=
Kinetic Examinations of P-C Reductive Elimination. A typi-
cal procedure (run 1 in Table 2) is as follows. Complex 1a (20.7
mg, 0.030 mmol) and 1,3,5-trimethoxybenzene (2.5 mg, 0.015
mmol; internal standard) were placed in an NMR sample tube
and dissolved in CD2Cl2 (ca. 0.5 mL) at -78 °C. PMePh2 (6.0
mg, 0.030 mmol) was added, and the total volume of the sample
solution was adjusted to 0.6 mL by adding a small amount of
CD2Cl2. The sample tube was placed in an NMR sample probe
controlled to 40.0 ( 0.1 °C. The reaction was examined at
intervals by 1H NMR spectroscopy using the following marker
signals: 1a (δ 5.69, CHdCH), 3a (δ 2.03, PMe), 4a (δ 3.04, PMe),
1,3,5-trimethoxybenzene (δ 6.10, Ar). All kinetic runs were
similarly conducted. The NMR data for 3a-c are as follows.
3a: 1H NMR (CD2Cl2, -20 °C) δ 7.82-7.77, 7.70-7.57,
7.52-7.27, 7.26-7.20, 7.14-7.06, 6.62-6.57, 6.52-6.43 (m,
2 Hz), 123.9 (dd, 1JPC = 82 Hz, 4JPC = 6 Hz), 65.5 (dd, 2JPC =31
Hz, 2JPC = 5 Hz), 33.2 (ddd, 1JPC = 80 Hz, 2JPC = 31 Hz, 2JPC
=
7 Hz), 12.2 (s), 14.3 (d, 2JPC = 19 Hz), 12.3(d, 2JPC = 20 Hz), 11.3
(d, 2JPC = 64 Hz); 31P{1H} NMR (CD2Cl2, -20 °C) δ 21.4 (d,
3JPP=12 Hz), 4.1 (s), 4.1 (d, 3JPP = 12 Hz).
Because the reductive elimination from 1d-g in the presence
of PMeAr02 was slow, detailed NMR analysis of the correspond-
ing styrylphosphonium complexes (3d-g) was performed with
the complexes independently prepared by P-C reductive elim-
ination from 1d-g in the absence of PMeAr02, followed by
complexation of the resulting [Pd(ArCHdCHPMeAr02)Br-
(PMeAr02)] (2d-g) with 1 equiv of PMeAr02 in CD2Cl2. A typical
procedure is as follows. Complex 1d (22.7 mg, 0.030 mmol) was
placed in an NMR sample tube and dissolved in CD2Cl2 (total 0.6
mL) at -78 °C. The solution was allowed to stand at 40 °C for 53 h.
3
3
1
35H in total), 3.60 (dddd, JHH = 10.8 Hz, JHP = 10.3 Hz,
3JHP = 6.3 Hz, 3JHP = 3.3 Hz, 1H), 3.55 (dddd, 2JHP = 19.6 Hz,
3JHH=10.8 Hz, 3JHP=8.7 Hz, 3JHP = 4.3 Hz, 1H), 1.85 (d, 2JHP
= 13.1 Hz, 3H), 1.54 (d, 2JHP = 5.3 Hz, 3H), 1.00 (d, 2JHP = 6.2
Hz, 3H); 13C{1H} NMR (CD2Cl2, -20 °C) δ 141.6 (dd, 3JPC=12
Hz, 3JPC = 7 Hz), 138.2 (dd, 1JPC = 29 Hz, 3JPC = 4 Hz), 137.1
The color gradually changed from colorless to orange. H NMR
analysis revealed the complete conversion of 1d and the formation
of 2d (94%) and a small amount of trans-[PdBr2(PMePh2)2] (3%).
PMePh2 (6.0 mg, 0.030 mmol) was added at room temperature,
and the resulting yellow solution of 3d was examined by NMR
spectroscopy. The NMR data of 2d-g and 3d-g are as follows.

Article
2d: 1H NMR (CD2Cl2, 20 °C) δ 8.04-7.96, 7.78-7.70,
7.70-7.63, 7.61-7.48, 7.29-7.12, 7.11-7.04, 6.99-6.92, 6.90-
6.81 (m, 24H in total), 3.42 (ddd, 2JHP=19.3 Hz, 3JHH = 10.7
Hz, 3JHP = 3.6 Hz, 1H), 3.16 (ddd, 3JHP = 13.2 Hz, 3JHH = 10.7
Hz, 3JHP = 8.5 Hz, 1H), 2.84 (d, 2JHP = 13.7 Hz, 3H), 1.60 (d,
2JHP = 6.5 Hz, 3H); 13C{1H} NMR (CD2Cl2, 20 °C) δ 149.0 (d,
3JPC = 12 Hz), 138.4 (d, 1JPC = 29 Hz), 136.6 (d, 1JPC = 30 Hz),
Organometallics, Vol. 29, No. 21, 2010 5577
1
2JPC = 38 Hz), 15.3 (d, JPC = 20 Hz), 13.9 (d, 1JPC = 66 Hz);
31P{1H} NMR (CD2Cl2, 20 °C) δ 19.2 (d, 3JPP = 8 Hz), 6.8 (dd,
3JPP = 8 Hz, 5JPF = 3 Hz).
3d: 1H NMR (CD2Cl2, -20 °C) δ 7.82-7.76, 7.70-7.63,
7.63-7.57, 7.52-7.22, 7.15-7.06 (m, 28H in total), 6.68 (d,
3JHH = 7.5 Hz, 2H), 6.51 (dd, 3JPC=10.2 Hz, 3JHH = 7.9 Hz,
2H), 6.42 (dd, 3JPC = 10.3 Hz, 3JHH=7.9 Hz, 2H), 3.83 (dddd,
3JHH = 10.7 Hz, 3JHP = 7.6 Hz, 3JHP = 7.1 Hz, 3JHP = 3.4 Hz,
1H), 3.54 (dddd, 2JHP = 19.9 Hz, 3JHH = 10.7 Hz, 3JHP = 9.0 Hz,
134.9 (d, 2JPC = 10 Hz), 133.7 (d, 4JPC = 3 Hz), 133.7 (d, 4JPC
=
3 Hz), 132.7 (d, 2JPC = 14 Hz), 132.5 (d, 2JPC = 10 Hz), 132.4 (d,
2JPC = 14 Hz), 130.0 (d, 3JPC = 11 Hz), 129.3 (d, 3JPC = 12 Hz),
129.2 (s), 129.2 (s), 128.4 (d, 3JPC = 9 Hz), 128.3 (d, 3JPC = 9
Hz), 126.9 (dd, 1JPC = 73 Hz, 4JPC = 10 Hz), 126.0 (q, 2JFC =32
Hz), 125.6 (q, 3JFC = 4 Hz), 125.4 (q, 1JFC = 271 Hz), 125.3 (s),
3JHP = 4.0 Hz, 1H), 1.95 (d, 2JHP = 13.1 Hz, 3H), 1.62 (d, 2JHP
5.6Hz, 3H), 1.10(d, 2JHP = 6.3Hz, 3H); 13C{1H} NMR (CD2Cl2,
=
3
3
-20 °C) δ 146.0 (dd, JPC = 13 Hz, JPC = 7 Hz), 137.7 (dd,
1JPC = 32 Hz, 3JPC = 3 Hz), 136.3 (dd, 1JPC = 32 Hz, 3JPC = 3
124.5 (d, 1JPC = 93 Hz), 57.8 (d, 2JPC = 5 Hz), 28.1 (dd, 1JPC
=
1
3
4
Hz), 135.7 (dd, JPC = 32 Hz, JPC = 1 Hz), 134.3 (d, JPC
=
81 Hz, 2JPC = 37 Hz), 14.8 (d, 1JPC = 19 Hz), 13.6 (d, 1JPC = 67
Hz); 31P{1H} NMR (CD2Cl2, 20 °C) δ 19.6 (d, 3JPP = 7 Hz), 7.6
(d, 3JPP=7 Hz).
3 Hz), 134.2 (d, 4JPC = 3 Hz), 135.1 (dd, 1JPC = 31 Hz, 3JPC = 1
Hz), 132.9 (d, 2JPC = 10 Hz), 132.7 (d, 2JPC = 10 Hz), 132.0 (d,
2JPC = 14 Hz), 131.7 (d, 2JPC = 13 Hz), 131.3 (d, 2JPC = 14 Hz),
130.9 (d, 2JPC = 13 Hz), 130.5 (m), 130.0 (m), 129.9 (d, 2JPC = 12
Hz), 129.7 (d, 2JPC = 12 Hz), 129.5 (m), 129.1 (d, 3JPC = 10 Hz),
129.1 (d, 3JPC = 9 Hz), 128.5 (d, 3JPC = 10 Hz), 128.5 (d, 3JPC = 9
Hz), 125.7 (brs), 124.6 (s), 123.9 (dd, 1JPC = 89 Hz, 4JPC = 2 Hz),
123.5 (dd, 1JPC = 83 Hz, 4JPC = 6 Hz), 63.4 (dd, 2JPC = 31 Hz,
2JPC=5 Hz), 33.7(ddd, 1JPC = 78 Hz, 2JPC=32 Hz, 2JPC = 7 Hz),
14.9 (d, 2JPC = 20 Hz), 12.8 (d, 2JPC = 20 Hz), 11.2 (d, 2JPC = 64
Hz); 31P{1H} NMR (CD2Cl2, -20 °C) δ 22.1 (dd, 3JPP = 12 Hz,
2JPP = 3 Hz), 4.8 (m, 2JPP = 3 Hz), 4.0 (s).
2e: 1H NMR (CD2Cl2, 20 °C) δ 8.04-7.96, 7.78-7.66, 7.60-
7.50, 7.31-7.25, 7.23-7.15, 7.11-7.06, 7.04-6.97, 6.95-6.88
(m, 22H in total), 6.77 (d, 3JHH = 8.7 Hz, 2H), 3.46 (ddd, 2JHP
18.8 Hz, 3JHH = 10.6 Hz, 3JHP = 4.0 Hz, 1H), 3.16 (ddd, 3JHP
=
=
=
12.5 Hz, 3JHH = 10.6 Hz, 3JHP = 8.7 Hz, 1H), 2.85 (d, 2JHP
2
13.7 Hz, 3H), 1.62 (d, JHP = 6.6 Hz, 3H); 13C{1H} NMR
3
3
(CD2Cl2, 20 °C) δ 152.6 (dd, JPC = 12 Hz, JPC = 1 Hz),
142.2 (s), 137.9 (d, 1JPC = 30 Hz), 136.4 (d, 1JPC = 31 Hz), 134.9
(d, 2JPC = 10 Hz), 133.8 (d, 4JPC = 3 Hz), 133.8 (d, 4JPC = 3
Hz), 132.8 (d, 2JPC = 14 Hz), 132.5 (d, 2JPC = 10 Hz), 132.4 (d,
3e: 1H NMR (CD2Cl2, -20 °C) δ 7.83 (d, 3JHH = 8.8 Hz, 2H),
7.82-7.76, 7.72-7.64, 7.63-7.56, 7.52-7.19, 7.16-7.06, 6.72-
6.63, 6.58-6.48 (m, 32H in total), 4.15 (dddd, 3JHH = 10.8 Hz,
3JHP = 7.8 Hz, 3JHP=7.1 Hz, 3JHP = 3.2 Hz, 1H), 3.59 (dddd,
2JHP = 20.0 Hz, 3JHH = 10.8 Hz, 3JHP = 9.4 Hz, 3JHP = 3.3 Hz,
1H), 2.02 (d, 3JHP = 13.2 Hz, 3H), 1.63 (d, 3JHP = 5.9 Hz, 3H),
1.07 (d, 3JHP3 = 6.4 Hz, 3H); 13C{1H} NMR (CD2Cl2, -20 °C) δ
2JPC =14Hz), 130.0(d, 3JPC = 11 Hz), 129.4 (m), 129.4 (d, 3JPC
=
12 Hz), 129.4 (d, 3JPC = 12 Hz), 128.4 (d, 3JPC = 9 Hz), 126.5 (dd,
1JPC = 74 Hz, 4JPC = 10 Hz), 125.0 (s), 124.4 (s), 124.2 (d, 1JPC
=
93 Hz), 57.7 (d, 2JPC = 6 Hz), 27.9 (dd, 1JPC = 81 Hz, 2JPC = 38
Hz), 14.8 (d, 1JPC = 20 Hz), 13.6 (d, 1JPC = 66 Hz); 31P{1H} NMR
(CD2Cl2, 20 °C) δ 20.1 (d, 3JPP = 8 Hz), 8.0 (d, 3JPP = 8 Hz).
1
3
3
2f: H NMR (CD2Cl2, 20 °C) δ 7.86 (dd, JHP = 12.5 Hz,
150.0 (dd, JPC = 12 Hz, JPC = 7 Hz), 144.4 (s), 137.4 (dd,
3JHH = 8.2 Hz, 2H), 7.69 (d, JHH = 9.1 Hz, 2H), 7.61 (dd,
3
1JPC = 31 Hz, 3JPC = 3 Hz), 135.9 (dd, 1JPC = 32 Hz, 3JPC
=
3JHP = 11.9 Hz, 3JHH = 8.2 Hz, 2H), 7.37 (dd, 3JHH = 7.9 Hz,
4JHP = 2.0 Hz, 2H), 7.32 (dd, 3JHH = 7.9Hz, 4JHP = 2.4 Hz, 2H),
2 Hz), 135.3 (d, 1JPC = 32 Hz), 134.3 (d, 4JPC = 3 Hz), 134.2 (d,
4JPC = 3 Hz), 132.1 (d, 1JPC = 31 Hz), 132.8 (d, 2JPC = 10 Hz),
3
2
2
6.99 (d, JHH = 8.2 Hz, 2H), 6.94-6.84, 6.81-6.73 (m, 8H in
132.6 (d, JPC = 10 Hz), 132.3 (d, JPC = 14 Hz), 131.8 (d,
2JPC = 14 Hz), 131.3 (d, 2JPC = 13 Hz), 130.8 (d, 2JPC = 13 Hz),
130.6 (m), 130.2 (m), 130.1 (m), 130.0 (d, 3JPC = 11 Hz), 129.9
(d, 3JPC = 11 Hz), 129.6 (m), 129.2 (d, 3JPC = 10 Hz), 129.1 (d,
3JPC = 10 Hz), 128.5 (d, 3JPC = 10 Hz), 128.5 (d, 3JPC = 9 Hz),
124.6 (s), 124.3 (s), 123.9 (dd, 1JPC = 87 Hz, 4JPC = 2 Hz), 123.3
total), 3.48 (ddd, 2JHP = 18.7Hz, 3JHH = 10.6Hz, 3JHP = 2.9 Hz,
1H), 3.09 (ddd, 3JHP = 12.5 Hz, 3JHH = 10.6 Hz, 3JHP = 8.7 Hz,
1H), 2.78 (d, 2JHP = 13.7 Hz, 3H), 2.44 (s, 3H), 2.43 (s, 3H), 2.33
(s, 3H), 2.24 (s, 3H), 1.58 (d, 2JHP = 6.7 Hz, 3H); 13C{1H} NMR
(CD2Cl2, 20 °C) δ 152.8 (d, 3JPC = 12 Hz), 144.8(d, 4JPC = 3 Hz),
144.8 (d, 4JPC = 3 Hz), 144.4 (s), 139.6 (d, 4JPC = 2 Hz), 139.4 (d,
4JPC = 2 Hz), 134.8 (d, 2JPC = 11 Hz), 134.4 (d, 1JPC = 31 Hz),
(dd, 1JPC = 83 Hz, 4JPC = 6 Hz), 63.2 (dd, 2JPC = 30 Hz, 2JPC
=
5 Hz), 34.2 (ddd, 1JPC=77 Hz, 2JPC = 33 Hz, 2JPC = 6 Hz), 15.0
(d, 2JPC = 19 Hz), 12.2 (d, 2JPC = 21 Hz), 11.2 (d, 2JPC = 63
Hz); 31P{1H} NMR (CD2Cl2, -20 °C) δ 22.5 (dd, 3JPP = 12 Hz,
133.1 (d, 1JPC = 32 Hz), 132.9 (d, 2JPC = 15 Hz), 132.5 (d, 2JPC
=
10 Hz), 132.2 (d, 2JPC = 14 Hz), 130.7 (d, 3JPC = 12 Hz), 130.0 (d,
3JPC = 13 Hz), 129.1 (d, 3JPC = 10 Hz), 129.1 (d, 3JPC = 10 Hz),
125.0 (s), 124.3 (s), 123.2 (dd, 1JPC = 76 Hz, 4JPC = 10 Hz), 120.8
(d, 1JPC = 95 Hz), 57.5 (d, 2JPC = 6 Hz), 27.9 (dd, 1JPC = 81 Hz,
3JPP = 3 Hz), 5.6 (d, 2JPP = 12 Hz, 3JPP = 12 Hz), 4.1 (dd, 2JPP
12 Hz, 3JPP = 3 Hz).
=
3f: 1H NMR (CD2Cl2, -20 °C) δ 7.87 (d, 3JHH = 8.6 Hz, 2H),
2JPC = 38 Hz), 22.1 (s), 22.0 (s), 21.5 (s), 21.4 (s), 15.0 (d, 1JPC
=
3
3
7.55 (d, JPH = 12.3 Hz, JHH =8.2 Hz, 2H), 7.42-7.06 (m,
14H), 6.93 (d, 3JHH = 6.9 Hz, 2H), 6.93 (d, 3JHH = 6.9 Hz, 2H),
6.86 (d, 3JHH = 7.0 Hz, 2H), 6.60 (brs, 2H), 6.42 (d, 3JPH = 10.5
Hz, 3JHH = 8.1 Hz, 2H), 6.44 (d, 3JPH=10.6 Hz, 3JHH = 8.1 Hz,
2H), 3.83 (dddd, 3JHH = 10.7 Hz, 3JHP = 8.4 Hz, 3JHP = 7.5 Hz,
3JHP = 3.4 Hz, 1H), 3.52 (dddd, 2JHP = 20.0 Hz, 3JHH = 10.7
15 Hz), 13.7 (d, 1JPC = 66 Hz); 31P{1H} NMR (CD2Cl2, 20 °C) δ
19.6 (d, 3JPP = 8 Hz), 6.4 (d, 3JPP = 8 Hz).
2g: 1H NMR (CD2Cl2, 20 °C) δ 8.04-7.96, 7.81-7.71, 7.32-
7.25, 7.22-7.16, 7.12-7.05, 7.00-6.89, 6.84-6.78 (m, 20H in
total), 3.45 (ddd, 2JHP = 18.8 Hz, 3JHH = 10.6 Hz, 3JHP = 3.1
Hz, 1H), 3.15 (ddd, 3JHP = 13.0 Hz, 3JHH = 10.6 Hz, 3JHP = 7.8
Hz, 1H), 2.84 (d, 2JHP = 13.7 Hz, 3H), 1.58 (d, 2JHP = 6.6 Hz,
3H); 13C{1H} NMR (CD2Cl2, -20 °C) δ 166.4 (dd, 1JFC = 257
Hz, 4JPC = 1 Hz), 166.2 (dd, 1JFC = 257 Hz, 4JPC = 2 Hz), 163.9
3
3
Hz, JHP = 9.7 Hz, JHP = 3.2 Hz, 1H), 2.49 (s, 3H), 2.39 (s,
3H), 2.35 (s, 3H), 2.30 (s, 3H), 2.29 (s, 3H), 2.28 (s, 3H), 1.89 (d,
3
3JHP = 13.2 Hz, 3H), 1.62 (d, JHP = 5.9 Hz, 3H), 1.04 (d,
3JHP = 6.4 Hz, 3H); 13C{1H} NMR (CD2Cl2, -20 °C) δ 150.2
(dd, 3JPC = 12 Hz, 3JPC = 7 Hz), 145.3 (d, 4JPC = 3 Hz), 144.8
(dd, 1JPC = 32 Hz, 3JPC = 2 Hz), 144.2 (d, 4JPC = 3 Hz), 144.2
(dd,1JFC =235Hz,4JPC = 1 Hz), 163.8 (dd, 1JFC =235Hz,4JPC
=
1 Hz), 152.4 (d, 3JPC = 11 Hz), 144.5 (s), 137.5 (dd, 2JPC = 12 Hz,
3JFC = 9 Hz), 135.2 (dd, 2JPC = 11 Hz, 3JFC = 9 Hz), 134.7 (dd,
2JPC = 14 Hz, 3JFC = 8 Hz), 134.4 (dd, 2JPC = 15 Hz, 3JFC=8 Hz),
133.2 (dd, 1JPC = 31 Hz, 4JFC = 3 Hz), 132.3 (dd, 1JPC=32 Hz,
(s), 140.9 (d, 4JPC = 2 Hz), 140.4 (d, 4JPC = 1 Hz), 140.3 (d, 4JPC
1 Hz), 139.8 (d, 4JPC = 2 Hz), 134.1 (dd, 1JPC = 32 Hz, 3JPC
3 Hz), 132.8 (d, 2JPC = 10 Hz), 132.7 (dd, 1JPC = 33 Hz, 3JPC
=
=
=
4JFC = 3 Hz), 125.3 (s), 124.4 (s), 122.0 (ddd, 1JPC = 80 Hz, 4JPC
=
1 Hz), 132.4 (d, 2JPC = 10 Hz), 132.1 (d, 2JPC = 14 Hz), 131.6 (d,
2JPC = 14 Hz), 131.2 (d, 2JPC = 14 Hz), 130.8 (d, 2JPC = 13 Hz),
10 Hz, 4JFC=4 Hz), 119.8 (dd, 1JPC = 97 Hz, 4JFC = 3 Hz), 117.7
(dd, 2JFC = 22 Hz, 3JPC = 13 Hz), 116.9 (dd, 2JFC = 22 Hz, 3JPC
14 Hz), 115.6 (dd, 2JFC = 21 Hz, 3JPC = 10 Hz), 115.6 (dd, 2JFC
=
=
130.5 (d, 3JPC = 13 Hz), 130.3 (d, 3JPC = 13 Hz), 129.7 (d, 3JPC
=
9 Hz), 129.6 (d, 3JPC = 9 Hz), 129.1 (d, 3JPC = 9 Hz), 124.4 (s),
124.2 (s), 120.3 (dd, JPC = 92 Hz, JPC = 1 Hz), 120.0 (dd,
1
4
21 Hz, 3JPC =10Hz), 57.0(d, 2JPC =5Hz), 28.5(dd, 1JPC =81Hz,

5578 Organometallics, Vol. 29, No. 21, 2010
Wakioka and Ozawa
1JPC = 84 Hz, 4JPC = 6 Hz), 62.9 (dd, 2JPC = 30 Hz, 2JPC = 5
Hz), 33.9 (ddd, 1JPC = 78 Hz, 2JPC = 34 Hz, 2JPC = 6 Hz), 21.9
(s), 21.8 (s), 21.4 (s), 21.3 (s), 21.3 (s), 21.3 (s), 15.0 (d, 2JPC = 21
3JFC = 8 Hz), 133.2 (dd, 2JPC = 15 Hz, 3JFC = 8 Hz), 132.9 (dd,
=
2JPC = 16 Hz, 3JFC = 9 Hz), 132.9 (dd, 2JPC = 15 Hz, 3JFC
9 Hz), 132.4 (ddd, 1JPC = 33 Hz, 3JPC = 3 Hz, 4JFC = 3 Hz), 131.1
2
2
1
3
4
Hz), 11.4 (d, JPC = 21 Hz), 11.4 (d, JPC = 64 Hz); 31P{1H}
(ddd, JPC = 33 Hz, JPC = 3 Hz, JFC = 3 Hz), 130.5 (ddd,
1JPC=36 Hz, 3JPC =2Hz,4JFC = 2 Hz), 128.1 (ddd, 1JPC =36Hz,
NMR (CD2Cl2, -20 °C) δ 21.9 (dd, 3JPP = 12 Hz, 3JPP = 3 Hz),
2
3
2
4.0 (d, JPP = 12 Hz, JPP = 12 Hz), 2.5 (dd, JPP = 12 Hz,
3JPP = 3 Hz).
3JPC = 3 Hz, 4JFC = 3 Hz), 124.1 (s), 124.1 (s), 120.5 (ddd, 1JPC
=
4
4
1
87 Hz, JPC = 4 Hz, JFC = 4 Hz), 119.9 (ddd, JPC = 91 Hz,
4JPC =4 Hz, 4JFC = 4 Hz), 117.0 (dd, 2JFC =21Hz, 3JPC=13 Hz),
116.2 (dd, 2JFC = 21 Hz, 3JPC = 10 Hz), 116.0 (dd, 2JFC = 21 Hz,
3JPC = 10 Hz), 115.6 (dd, 2JFC = 21 Hz, 3JPC = 10 Hz), 115.6 (dd,
2JFC =21Hz, 3JPC =10Hz), 62.4(dd,2JPC =31Hz,2JPC =5 Hz),
34.6 (ddd, 1JPC = 77 Hz, 2JPC = 33 Hz, 2JPC = 6 Hz), 15.4 (d,
2JPC = 20 Hz), 12.9 (d, 2JPC = 21 Hz), 11.3 (d, 2JPC = 64 Hz);
31P{1H} NMR (CD2Cl2, -50 °C) δ 22.0 (d, 3JPP = 13 Hz), 5.0 (m,
2JPP = 13 Hz, 3JPP = 13 Hz), 3.2 (m).
3g: 1H NMR (CD2Cl2, -50 °C) δ 7.93-7.83, 7.83-7.76,
7.33-7.00, 6.96-6.89, 6.82-6.76, 6.74-6.66, 6.50-6.42 (m,
3
3
28H in total), 4.66 (dddd, JHH = 10.8 Hz, JHP = 7.3 Hz,
3JHP = 7.1 Hz, 3JHP = 3.3 Hz, 1H), 3.79 (dddd, 2JHP = 20.2 Hz,
3JHH = 10.8 Hz, 3JHP = 9.5 Hz, 3JHP = 3.1 Hz, 1H), 2.40 (d,
2JHP = 10.2 Hz, 3H), 1.62 (d, 2JHP = 5.8 Hz, 3H), 1.21 (d, 2JHP
= 6.3 Hz, 3H); 13C{1H} NMR (CD2Cl2, -50 °C) δ 165.7 (dd,
1JFC = 257 Hz, 4JPC = 1 Hz), 165.7 (dd, 1JFC = 257 Hz, 4JPC
=
1
1 Hz), 163.7 (dd, JFC = 252 Hz, JPC = 1 Hz), 163.5 (dd,
4
1JFC = 251 Hz, 4JPC = 1 Hz), 163.3 (dd, 1JFC = 250 Hz, 4JPC
1 Hz), 163.1 (dd, 1JFC = 252 Hz, 4JPC = 1 Hz), 149.6 (dd, 3JPC
=
=
Acknowledgment. This work was supported by Grants-
in-Aid for Scientific Research from the Ministry of
Education, Culture, Sports, Science, and Technology of
Japan.
13 Hz, 3JPC = 7 Hz), 144.0 (s), 135.2 (dd, 2JPC = 21 Hz, 3JFC= 10
Hz), 134.1 (dd, 2JPC=16 Hz, 3JFC=8 Hz), 133.5 (dd, 2JPC = 15 Hz,