Alkyne insertion into cis-silyl(stannyl)platinum(II) complexes

Article abstract of DOI:10.1021/om030553t

A series of cis-silyl(stannyl)platinum(II) complexes have been prepared by oxidative addition of silylstannanes to Pt(cod)₂ in toluene in the presence of tertiary phosphine ligands: cis-Pt(SiR₃)(SnMe₃)L₂ [L = PMe₂Ph, SiR₃ = SiMe₃ (1a), SiMe₂Ph (1b), SiMePh₂ (1c), SiPh₃ (1d); SiR₃ = SiMe₂Ph, L = PMe₃ (1e), PEt₃ (1f), PMePh₂ (1g)]. These complexes undergo competitive insertion of alkynes (RC≡CH) into the Pt-Sn and Pt-Si bonds under kinetic conditions to give the insertion complexes cis-Pt{C(R)=CHSnMe₃}(SiR₃)L₂ (2) and cis-Pt(SnMe₃){C(R)=CHSiR₃}L₂ (3), respectively. Furthermore, once 2 is formed in the reaction systems, it is converted to 3 under thermodynamic conditions. The kinetic ratio of 2 to 3 is significantly affected by the silyl and phosphine ligands as well as the alkynes employed. Thus, in the insertion of phenylacetylene, the kinetic ratio changes depending on the silyl and phosphine ligands attached to the complexes as follows: 2/3 = 0/100 (1a), 30/70 (1b), 59/41 (1c), 93/7 (1d), 36/64 (1e), 25/75 (1f), 25/75 (1g). On the other hand, in the reactions of 1b, the kinetic ratio varies with alkynes as follows: 2/3 = 12/88 (p-H₂NC₆H₄C≡ CH), 28/72 (p-MeC₆H₄C≡CH), 30/70 (PhC≡CH), 46/54 (p-OHCC₆H₄C≡CH), 100/0 (MeO₂-CC≡CCO₂Me). Reasons for the variations are discussed on the basis of the insertion mechanism elucidated by kinetic investigations.

Full text of DOI:10.1021/om030553t

Organometallics 2003, 22, 4433-4445
4433
Alk yn e In ser tion in to cis-Silyl(sta n n yl)p la tin u m (II)
Com p lexes
Takashi Sagawa, Yasunobu Sakamoto, Rika Tanaka, Hiroyuki Katayama,† and
Fumiyuki Ozawa*,†
Department of Applied Chemistry, Graduate School of Engineering, Osaka City University,
Sumiyoshi-ku, Osaka 558-8585, J apan
Received J uly 25, 2003
A series of cis-silyl(stannyl)platinum(II) complexes have been prepared by oxidative
addition of silylstannanes to Pt(cod)2 in toluene in the presence of tertiary phosphine
ligands: cis-Pt(SiR3)(SnMe3)L2 [L ) PMe2Ph, SiR3 ) SiMe3 (1a ), SiMe2Ph (1b), SiMePh2
(1c), SiPh3 (1d ); SiR3 ) SiMe2Ph, L ) PMe3 (1e), PEt3 (1f), PMePh2 (1g)]. These complexes
undergo competitive insertion of alkynes (R′CtCH) into the Pt-Sn and Pt-Si bonds under
kinetic conditions to give the insertion complexes cis-Pt{C(R′)dCHSnMe3}(SiR3)L2 (2) and
cis-Pt(SnMe3){C(R′)dCHSiR3}L2 (3), respectively. Furthermore, once 2 is formed in the
reaction systems, it is converted to 3 under thermodynamic conditions. The kinetic ratio of
2 to 3 is significantly affected by the silyl and phosphine ligands as well as the alkynes
employed. Thus, in the insertion of phenylacetylene, the kinetic ratio changes depending on
the silyl and phosphine ligands attached to the complexes as follows: 2/3 ) 0/100 (1a ), 30/
70 (1b), 59/41 (1c), 93/7 (1d ), 36/64 (1e), 25/75 (1f), 25/75 (1g). On the other hand, in the
reactions of 1b, the kinetic ratio varies with alkynes as follows: 2/3 ) 12/88 (p-H2NC6H4Ct
CH), 28/72 (p-MeC6H4CtCH), 30/70 (PhCtCH), 46/54 (p-OHCC6H4CtCH), 100/0 (MeO2-
CCtCCO2Me). Reasons for the variations are discussed on the basis of the insertion
mechanism elucidated by kinetic investigations.
Sch em e 1
In tr od u ction
Addition of inter-element linkages to carbon-carbon
multiple bonds catalyzed by group 10 metal complexes
has attracted a great deal of recent interest.1 Scheme 1
shows a generally accepted catalytic cycle for the
reaction using a terminal alkyne as a substrate, which
consists of three elementary processes a-c. Oxidative
addition of an element-element bond to a low-valent
metal species (A) gives intermediate B bearing two
metal-element bonds (process a), which subsequently
undergoes insertion of alkyne into one of the metal-
element bonds to give insertion complex C or C′ (process
b). Reductive elimination from C or C′ forms addition
product D with regeneration of A (process c). We are
currently interested in the mechanisms of processes b
and c,2-4 which have been much less explored than the
oxidative addition process a.1
In this paper, we wish to describe a detailed mecha-
nistic study of alkyne insertion into cis-silyl(stannyl)-
platinum(II) complexes, which are models of key inter-
mediates for palladium-catalyzed silylstannylation of
unsaturated hydrocarbons.5 Although this process has
* Corresponding author. E-mail: ozawa@scl.kyoto-u.ac.jp.
† Present address: Institute for Chemical Research, Kyoto Univer-
sity, Uji, Kyoto 611-0011, J apan.
(1) (a) Beletskaya, I.; Moberg, C. Chem. Rev. 1999, 99, 3435. (b) Han,
L.-B.; Tanaka, M. Chem. Commun. 1999, 395. (c) Suginome, M.; Ito,
Y. Chem. Rev. 2000, 100, 3221. (d) Kondo, T.; Mistudo, T. Chem. Rev.
2000, 100, 3205.
(2) (a) Ozawa, F. J . Organomet. Chem. 2000, 611, 332. (b) Ozawa,
F.; Kamite, J . Organometallics 1998, 17, 5630. (c) Sagawa, T.; Asano,
Y.; Ozawa, F. Organometallics 2002, 21, 5879. (d) Ozawa, F.; Hikida,
T. Organometallics 1996, 15, 4501. (e) Hikida, T.; Onitsuka, K.;
Sonogashira, K.; Hayashi, T.; Ozawa, F. Chem. Lett. 1995, 985. (f)
Ozawa, F.; Sugawara, M.; Hayashi, T. Organometallics 1994, 13, 3237.
(g) Ozawa, F.; Sugawara, M.; Hasebe, K.; Hayashi, T. Inorg. Chim.
Acta 1999, 296, 19. (h) Hasebe, K.; Kamite, J .; Mori, T.; Katayama,
H.; Ozawa, F. Organometallics 2000, 19, 2022. (i) Ozawa, F.; Kitaguchi,
M.; Katayama, H. Chem. Lett. 1999, 1289. (j) Ozawa, F.; Hikida, T.;
Hasebe, K.; Mori, T. Organometallics 1998, 17, 1018. (k) Ozawa, F.;
Hikida, T.; Hayashi, T. J . Am. Chem. Soc. 1994, 116, 2844. (l) Ozawa,
F.; Mori, T. Organometallics 2003, 22, in press.
(3) For related mechanistic studies, see: (a) Iverson, C. N.; Smith,
M. R., III. Organometallics 1996, 15, 5155. (b) Lesley, G.; Nguyen, P.;
Taylor, N. J .; Marder, T. B. Organometallics 1996, 15, 5137. (c)
Mochida, K.; Wada, T.; Suzuki, K.; Hatanaka, W.; Nishiyama, Y.;
Nanjo, M.; Sekine, A.; Ohashi, Y.; Sakamoto, M.; Yamamoto, A. Bull.
Chem. Soc. J pn. 2001, 74, 123. (d) Ananikov, V.; Beletskaya, I.;
Aleksandrov, G.; Eremenko, I. Organometallics 2003, 22, 1414.
(4) For theoretical treatment of catalytic processes, see: (a) Hada,
M.; Tanaka, Y.; Ito, M.; Murakami, M.; Amii, H.; Ito, Y.; Nakatsuji,
H. J . Am. Chem. Soc. 1994, 116, 8754. (b) Sakaki, S.; Ogawa, M.;
Musashi, Y. J . Organomet. Chem. 1997, 535, 25. (c) Bottoni, A.;
Higueruelo, A. P.; Miscione, G. P. J . Am. Chem. Soc. 2002, 124, 5506.
(d) Cui, Q.; Musaev, D. G.; Morokuma, K. Organometallics 1997, 16,
1355. (e) Sakaki, S.; Kikuno, K. Inorg. Chem. 1997, 36, 226. (f) Cui,
Q.; Musaev, D. G.; Morokuma, K. Organometallics 1998, 17, 1383.
10.1021/om030553t CCC: $25.00 © 2003 American Chemical Society
Publication on Web 09/20/2003

4434 Organometallics, Vol. 22, No. 22, 2003
Sagawa et al.
Sch em e 2
been once examined theoretically,4a its experimental
study has been extremely limited to date,6 probably due
to instability of silyl(stannyl)palladium(II) complexes.
On the other hand, we have found in this study that a
series of platinum analogues are successfully prepared
by oxidative addition of silylstannanes to platinum(0)
complexes and detailed information about the insertion
mechanism is gained by kinetic examinations.7 A par-
ticular interest has been focused on site selectivity in
alkyne insertion. Thus, silyl(stannyl) complexes have
two metal-element bonds capable of undergoing the
insertion. A previous theoretical study using cis-Pd-
(SiH3)(SnH3)(PH3)2 has predicted that insertion into the
Pd-Sn bond is preferable to that into the Pd-Si bond
under kinetic conditions.4a On the other hand, for the
platinum analogues, relative ease of the insertion into
Pt-Si and Pt-Sn bonds has been found to dramatically
vary with the types of silyl and phosphine ligands and
alkynes employed.
Resu lts
F igu r e 1. 31P{1H} NMR spectra of 1d , 2d , and 3d in CD2-
Cl2 at 121.5 MHz. Complexes 1d and 3d were examined
after isolation, whereas 2d was generated in situ from 1d
and phenylacetylene (1.1 equiv) in CD2Cl2 in the presence
of added PMe2Ph (1 equiv) and examined without isolation.
A broad singlet arising from free PMe2Ph (δ -44.0) in
spectrum b was omitted for simplicity.
Syn th esis of cis-P t(SiR3)(Sn Me3)L2. Silyl-stannyl
complexes listed in Scheme 2 were prepared by the
reactions of Pt(cod)2 with silylstannanes and phos-
phines. For example, Pt(cod)2 was dissolved in toluene
and successively treated with Ph3SiSnMe3 (1 equiv) and
PMe2Ph (2 equiv) at 0 °C. 31P{1H} NMR analysis of the
resulting solution revealed selective formation of 1d ,
which was isolated as a yellow crystalline solid in 38%
yield. In this procedure, Ph3SiSnMe3 must be added
prior to PMe2Ph; otherwise Pt(cod)(PMe2Ph)2 is exclu-
sively formed in the system. Similar phenomena oc-
curred for all silyl-stannyl complexes. Especially, PMe3-
coordinated 1e was obtained as a 1:1 mixture with
Pt(cod)(PMe3)2 even in the proper order of addition,
while Pt(cod)(PMe3)2 was successfully removed by wash-
ing the crude product with Et2O-pentane (1:3), and 1e
was isolated as an analytically pure compound in 35%
yield.
Figure 1a shows the 31P{1H} NMR spectrum of 1d
measured at -50 °C in CD2Cl2. Two sets of doublets
with 117Sn, 119Sn, and 195Pt satellites are observed. The
(5) (a) Mitchell, T. N.; Killing, H.; Dicke, R.; Wickenkamp, R. J .
Chem. Soc., Chem. Commun. 1985, 354. (b) Chenard, B. L.; Laganis,
E. D.; Davidson, F.; RajanBabu, T. V. J . Org. Chem. 1985, 50, 3666.
(c) Chenard, B. L.; Van Zyl, C. M. J . Org. Chem. 1986, 51, 3561. (d)
Mitchell, T. N.; Wickenkamp, R.; Amamria. A.; Dicke, R.; Schneider,
U. J . Org. Chem. 1987, 52, 4868. (e) Murakami, M.; Amii, H.;
Takizawa, N.; Ito, Y. Organometallics 1993, 12, 4223. (f) Obora, Y.;
Tsuji, Y.; Asayama, M.; Kawamura, T. Organometallics 1993, 12, 4697.
(g) Tsuji, Y.; Obora, Y. J . Am. Chem. Soc. 1991, 113, 9368. (h)
Murakami, M.; Morita, Y.; Ito, Y. J . Chem. Soc., Chem. Commun. 1990,
428. (i) Mitchell, T. N.; Schneider, U. J . Organomet. Chem. 1991, 407,
319. (j) J eganmohan, M.; Shanmugasundaram, M.; Chang, K.-J .;
Cheng, C.-H. Chem. Commun. 2002, 2552. (k) Obora, Y.; Tsuji, Y.;
Kakehi, T.; Kobayashi, M.; Shinkai, Y.; Ebihara, M.; Kawamura, T. J .
Chem. Soc., Perkin Trans. 1 1995, 599. (l) Mori, M.; Hirose, T.;
Wakamatsu, H.; Imakuni, N.; Sato, Y. Organometallics 2001, 20, 1907.
(m) Shin, S.; RajanBabu, T. V. J . Am. Chem. Soc. 2001, 123, 8416.
(6) Murakami, M.; Yoshida, T.; Kawanami, S.; Ito, Y. J . Am. Chem.
Soc. 1995, 117, 6408.
2
doublet at δ -9.7 with large J SnP couplings [1559
(
119Sn), 1499 Hz (117Sn)] is due to the phosphine trans
to the SnMe3 ligand, whereas the other doublet at δ
2
-5.4 with relatively small J SnP couplings [185 (119Sn),
177 Hz (117Sn)] is assignable to the phosphine cis to the
1
SnMe3 ligand (i.e., trans to the SiPh3 ligand). The J PtP
value for the latter signal (1663 Hz) is significantly
smaller than that for the former one (2331 Hz), and this
tendency is consistent with the greater trans influence
of the silyl ligand than the stannyl ligand.
The 31P{1H} NMR signals of 1d broadened at elevated
temperature and coalesced into a broad singlet involving
1
195Pt satellites at 35 °C (δ -7.6, J PtP ) 1997 Hz). The
(7) A part of this study has been communicated: Ozawa, F.;
Sakamoto, Y.; Sagawa, T.; Tanaka, R.; Katayama, H. Chem. Lett. 1999,
1307.
coalescence temperature was not affected by addition
of free PMe2Ph (1 equiv) to the system. A similar type

Alkyne Insertion into cis-Silyl(stannyl) Pt(II)
Organometallics, Vol. 22, No. 22, 2003 4435
Sch em e 4
F igu r e 2. X-ray structure of 1d ‚THF. Hydrogen atoms
and THF molecule are omitted for clarity. Selected bond
distances (Å) and angles (deg): Pt-Si ) 2.362(2), Pt-Sn
) 2.6079(5), Pt-P(1) ) 2.352(2), Pt-P(2) ) 2.323(2), Si-
Pt-Sn ) 86.20(5), P(1)-Pt-P(2) ) 96.60(7), Si-Pt-P(1) )
158.76(7), Si-Pt-P(2) ) 94.27(6), Sn-Pt-P(1) ) 91.61-
(5), Sn-Pt-P(2) ) 154.69(5).
1
Sch em e 3a
trans to the silyl ligands involve relatively small J PtP
values (1419-1663 Hz), whereas those trans to the
1
SnMe3 ligand exhibit J PtP values of 2318-2513 Hz. The
coalescence temperatures (Tc) vary significantly with the
sorts of silyl and phosphine ligands. Thus, Tc rises
according to the silyl ligands in the order SiMe3 (1a ) <
SiMe2Ph (1b) < SiMePh2 (1c) < SiPh3 (1d ) and accord-
ing to the phosphine ligands in the order PEt3 (1f) ≈
PMePh2 (1g) < PMe2Ph (1b) < PMe3 (1e). The observed
orders seem to reflect a delicate balance of electronic
and steric effects.
Alkyn e In ser tion in to cis-P t(SiR3)(Sn Me3)L2. Com-
plexes 1 reacted with alkynes in solution to give two
types of products, 2 and 3, which are formed by the
insertion into Pt-Sn and Pt-Si bonds, respectively
(Scheme 4). The ratio of 2 to 3 varied significantly with
the types of silyl and phosphine ligands, alkynes em-
ployed, and reaction conditions. As described below in
detail, two types of processes are operative. One is
competitive formation of 2 and 3, and the other is
subsequent conversion of 2 to 3.
a
A, B ) SiR3, SnMe3.
of NMR behavior has already been documented for bis-
(silyl)- and bis(stannyl)platinum(II) complexes by Tsuji
et al. and attributed to the occurrence of twist-rotation
via a pseudo-tetrahedral transition state on an NMR
time scale (Scheme 3).8 Although fluxional behavior of
this type has never been observed for dialkylplatinum-
(II) analogues, it becomes feasible when highly electron-
releasing silyl and stannyl ligands are coordinated to
platinum.
(a ) Rea ction of 1d w ith P h en yla cetylen e. Com-
plex 1d rapidly reacted with phenylacetylene (10 equiv)
in CDCl3 at 50 °C to give the insertion complex into the
Pt-Si bond (3d ), selectively. On the other hand, the
same reaction examined in the presence of 1 equiv/1d
of added PMe2Ph proceeded gradually at the same
temperature to afford a mixture of 3d and 2d , the latter
of which is the insertion complex into the Pt-Sn bond.
Figure 3a shows the time course. It is seen that 2d and
3d are simultaneously formed at the expense of 1d . The
ratio of 2d to 3d remains almost constant (93/7) during
the reaction. Conversion of 1d obeyed good pseudo-first-
order kinetics up to 80% conversion (kobsd ) 1.02(2) ×
10-4 s-1).
When the amount of added PMe2Ph was reduced to
0.1 equiv/1d , the insertion reaction proceeded much
more rapidly (see Figure 3b). Furthermore, 2d once
formed in the reaction system was subsequently con-
verted to 3d . Thus, the amount of 2d reaches the
maximum (69%) after 20 min and then decreases with
increasing amount of 3d . The initial ratio of 2d to 3d is
93/7, and this value is in good agreement with that
observed for Figure 3a.
The structurally flexible nature of 1d was also sug-
gested by X-ray crystallography. As seen from the
ORTEP diagram in Figure 2, the complex has signifi-
cantly distorted square-planar geometry around plati-
num. The Pt-Si and Pt-Sn bonds are tilted from the
PtP2 plane by 18.2° and 24.0°, respectively, toward
opposite directions from each other. Thus, the deviation
from the ideal coordination plane is more remarkable
for the SnMe3 ligand than the SiPh3 ligand, indicating
more the flexible nature of the Pt-Sn bond than the
Pt-Si bond. The Pt-P(1) bond (2.352(2) Å) trans to the
silyl ligand is clearly longer than the Pt-P(2) bond
(2.323(2) Å) trans to the stannyl ligand, reflecting the
higher trans influence of the silyl ligand than the
stannyl ligand.
Table 1 lists the 31P{1H} NMR data for 1a -g at -50
°C, together with the coalescence temperatures for the
two doublet signals. The signals due to the phosphines
(8) (a) Obora, Y.; Tsuji, Y.; Nishiyama, K.; Ebihara, M.; Kawamura,
T. J . Am. Chem. Soc. 1996, 118, 10922. (b) Tsuji, Y.; Nishiyama, K.;
Hori, S.; Ebihara, M.; Kawamura, T. Organometallics 1998, 17, 507.
(c) Tsuji, Y.; Obora, Y. J . Organomet. Chem. 2000, 611, 343. (d) Wendt,
O. F.; Deeth, R. J .; Elding, L. I. Inorg. Chem. 2000, 39, 5271.

4436 Organometallics, Vol. 22, No. 22, 2003
Ta ble 1. 31P {1H} NMR Da ta for cis-P t(SiR3)(Sn Me3)L2 (1a -g)a
Sagawa et al.
119SnP
117SnP
(Hz)
complex
SiR3
L
δ (ppm)
2J PP (Hz)
1J PtP (Hz)
2J
(Hz)
2J
Tc (°C)
-15
1a
SiMe3
PMe2Ph
-5.3 (d)
-5.7 (d)
-6.1 (d)
-8.3 (d)
-6.4 (d)
-9.8 (d)
-5.4 (d)
-9.7 (d)
-15.1 (d)
-17.8 (d)
14.5 (br,d)
13.6 (br,d)
9.3 (br,d)
6.2 (br,d)
28
28
26
26
25
25
25
25
27
27
23
23
21
21
1419
2392
1526
2379
1606
2352
1663
2331
1464
2318
1629
2513
1596
2461
196
1634
194
1616
187
1561
185
1559
201
1645
192
1577
184
1544
181
1510
177
1449
193
1521
1b
1c
1d
1e
1f
SiMe2Ph
SiMePh2
SiPh3
PMe2Ph
PMe2Ph
PMe2Ph
PMe3
5
15
35
SiMe2Ph
SiMe2Ph
SiMe2Ph
20
PEt3
185b
1616b
197b
-30
-25
1g
PMePh2
1540b
a
b
In CD2Cl2, at -50 °C. The 2J
and 2J
119SnP
117SnP
values were not resolved due to broadening of the satellite signals.
analysis. Although 2d was not isolated owing to the
occurrence of its conversion to 3d , the formation of this
complex was clearly confirmed by 1H, 13C{1H}, and 31P-
{1H} NMR spectroscopy. Figures 1b and 1c show the
31P{1H} NMR spectra of 2d and 3d , respectively. The
site of phenylacetylene insertion (i.e., Pt-Sn or Pt-Si
bond) could be confirmed with these spectra. Thus, 2d
exhibits two sets of doublets with 195Pt satellites at δ
-10.9 (1J PtP ) 1324 Hz) and -15.5 (1J PtP ) 1889 Hz).
1
The J PtP values are comparable to those of cis-Pt-
(SiPh3){C(Ph)dCH(SiPh3)}(PMe2Ph)2 (1246 and 1820
Hz),2b cis-Pt(SiPh3)-{CHdCH(SiPh3)}(PMe2Ph)2 (1390
and 1821 Hz),2b and cis-Pt(SiPh3)(CHdCH2)(PMe2Ph)2
(1342 and 1988 Hz).2a The occurrence of the insertion
into the Pt-Sn bond is also supported by the absence
of P-Sn couplings in the signals. In contrast, the signals
of 3d in Figure 1c involve the satellites due to the
coupling to 117Sn and 119Sn nuclei, in addition to the
1
195Pt satellites. The J PtP values (2081 and 1975 Hz)
observed for 3d are consistent with a structure having
stannyl and alkenyl ligands in mutually cis positions.
The regiochemistry of phenylacetylene insertion giv-
ing the structures “Pt-C(Ph)dCH-(SnMe3)” in 2d and
“Pt-C(Ph)dCH(SiPh3)” in 3d was confirmed by 13C
NMR spectroscopy. The R-vinylic carbon signal of 2d
2
appeared at δ 169.4 (dd, J PC ) 99 and 17 Hz) with a
large coupling to 195Pt (1J PtC ) 713 Hz), and this signal
vanished in a DEPT NMR spectrum because of the
absence of a proton on this carbon. Similarly, the
2
R-carbon signal of 3d at δ 184.3 (dd, J PC) 101 and 13
1
Hz, J PtC ) 719 Hz) disappeared in a DEPT NMR
spectrum.
(b) Effect of Silyl a n d P h osp h in e Liga n d s. Reac-
tions of 1a -g with phenylacetylene were similarly
examined in the presence of 0.1 equiv/1 of added
phosphines (Table 2). The reaction of 1a was complete
in a few minutes even at -70 °C, giving the insertion
complex into the Pt-SiMe3 bond (3a ), selectively (run
1). Complexes 1b and 1e-g, bearing a SiMe2Ph ligand,
reacted with phenylacetylene at -5 °C to give kinetic
mixtures of 2 and 3, respectively (runs 2, 5-7); the
ratios of 2 to 3 were unchanged at this temperature but
converged to 3 at room temperature. Complexes 1c and
1d were less reactive and underwent insertion of
phenylacetylene at elevated temperatures (runs 3, 4).
As already shown for 1d (Figure 3b), these systems
involved competitive formation of 2 and 3 and subse-
quent conversion of 2 to 3.
F igu r e 3. Time course of the reaction of 1d with pheny-
lacetylene in CDCl3 in the presence of added PMe2Ph at
50 °C. Initial concentration: [1d ]0 ) 20 mM, [PhCtCH] )
0.20 M, [PMe2Ph]0 ) 20 (a) or 2.0 mM (b).
The following points have emerged: (1) Insertion
reactions into the Pt-Sn and Pt-Si bonds compete with
each other under kinetic conditions, giving a 93/7 ratio
of 2d and 3d at 50 °C. (2) Complex 2d is entirely
converted to 3d under thermodynamic conditions. (3)
Both processes are retarded by addition of free PMe2-
Ph to the system.
Complex 3d was isolated as a white crystalline solid
and identified by NMR spectroscopy and elemental

Alkyne Insertion into cis-Silyl(stannyl) Pt(II)
Organometallics, Vol. 22, No. 22, 2003 4437
Ta ble 2. Rea ction s of 1a -g w ith P h en yla cetylen ea
b
reaction 103kobsd
run complex
SiR3
L
temp (°C)
(s-1
)
2:3c
1
2
1a
1b
1c
1d
SiMe3
SiMe2Ph PMe2Ph
SiMePh2 PMe2Ph
PMe2Ph
-70
-5
15
rapid
1.50(1)
0.326(3) 59:41
1.2(1)
0:100
30:70
3
4d
SiPh3
PMe2Ph
50
93:7
5
6
7
1e
1f
1g
SiMe2Ph PMe3
SiMe2Ph PEt3
SiMe2Ph PMePh2
-5
-5
-5
2.4(1)
0.413(2) 25:75
0.801(1) 25:75
36:64
a
Reactions were performed in CD2Cl2 in the presence of added
phosphines (L) unless otherwise noted. Initial concentration: [1]0
b
) 20 mM, [PhCtCH]0 ) 0.20 M, [L]0 ) 2.0 mM. Rate constants
for the conversion of 1, estimated by least-squares treatment of
first-order plots at least for two half-lives. c The ratio of insertion
d
products under kinetic conditions. In CDCl3.
Ta ble 3. Rea ction s of 1b w ith Sever a l Alk yn esa
b
run
alkyne
103kobsd (s-1
)
2:3c
F igu r e 4. X-ray structure of 2k . Hydrogen atoms are
omitted for clarity. Selected bond distances (Å) and angles
(deg): Pt-Si ) 2.394(2), Pt-P(1) ) 2.377(2), Pt-P(2) )
2.306(2), Pt-C(1) ) 2.099(6), C(1)-C(2) ) 1.30(1), C(1)-
C(3) ) 1.52(1), C3(1)-O(1) ) 1.195(8), C(3)-O(2) ) 1.328-
(8), O(2)-C(4) ) 1.449(9), C(2)-Sn ) 2.168(6), C(2)-C(5)
) 1.480(9), C(5)-O(3) ) 1.220(8), C(5)-O(4) ) 1.373(9),
O(4)-C(6) ) 1.42(1), Si-Pt-C(1) ) 83.9(2), P(1)-Pt-P(2)
) 96.42(6), Si-Pt-P(1) ) 172.20(6), Si-Pt-P(2) ) 91.34-
(7), P(1)-Pt-C(1) ) 88.3(2), P(2)-Pt-C(1) ) 175.2(2), Pt-
C(1)-C(2) ) 128.9(6), Pt-C(1)-C(3) ) 107.9(5), C(2)-
C(1)-C(3) ) 123.1(6), Sn-C(2)-C(1) ) 127.4(5), Sn-C(2)-
C(5) ) 114.0(5), C(1)-C(2)-C(5) ) 118.5(6), O(1)-C(3)-
O(2) ) 125.0(6), O(1)-C(3)-C(1) ) 123.1(6), O(2)-C(3)-
C(1) ) 111.8(5), O(3)-C(5)-O(4) ) 120.0(6), O(3)-C(5)-
C(2) ) 129.0(7), O(4)-C(5)-C(2) ) 111.0(6), C(3)-O(2)-
C(4) ) 114.1(6), C(5)-O(4)-C(6) ) 118.0(6).
1
2
3
4
5
p-H2NC6H4CtCH
p-MeC6H4CtCH
PhCtCH
p-OHCC6H4CtCH
MeO2CCtCCO2Me
1.20(2)
1.24(3)
1.50(1)
rapid
12:88
28:72
30:70
46:54
100:0
rapid
a
Reactions were performed in CD2Cl2 at -5 °C in the presence
of added PMe2Ph. Initial concentration: [1b]0 ) 20 mM, [alkyne]0
) 0.20 M, [PMe2Ph]0 ) 2.0 mM. b Rate constants for the conversion
of 1b, estimated by least-squares treatment of first-order plots at
least for two half-lives. c The ratio of insertion products under
kinetic conditions.
Table 2 suggests the following points: (1) The reactiv-
ity of 1 decreases according to silyl and phosphine
ligands in the order SiMe3 (1a ) > SiMe2Ph (1b) >
SiMePh2 (1c) > SiPh3 (1d ); PMe3 (1e) > PMe2Ph (1b)
> PMePh2 (1g) > PEt3 (1f). (2) The kinetic ratio of 2 to
3 increases according to silyl ligands [SiMe3 (1a ) <
SiMe2Ph (1b) < SiMePh2 (1c) < SiPh3 (1d )] and to
phosphine ligands [PEt3 (1f) ) PMePh2 (1g) < PMe2Ph
(1b) ≈ PMe3 (1e)]. The effect of silyl ligands is particu-
larly remarkable, and the kinetic ratio varies from 0/100
to 93/7.
(c) Effect of Alk yn es. Table 3 compares the reac-
tions of 1b with several acetylenes in CD2Cl2 at -5 °C.
It is seen that the acetylene bearing more electron-
withdrawing substituent(s) tends to give a higher
reactivity and a higher kinetic ratio of 2. The mixtures
of insertion products formed in runs 1-4 were entirely
converted to 3 at room temperature. On the other hand,
2k , formed by the insertion of dimethyl acetylenedicar-
boxylate into the Pt-Sn bond of 1b, was exceptionally
stable and isolated as a crystalline solid suitable for
X-ray diffraction analysis.
Figure 4 shows the ORTEP diagram of 2k . The
complex adopts square-planar geometry; the sum of the
four angles around platinum is 360.0°. The Pt-P(1)
bond (2.377(2) Å) is significantly longer than the Pt-
P(2) bond (2.306(2) Å), reflecting the difference in trans
influence of silyl and alkenyl ligands. The SnMe3 group
is bonded to the â-vinylic carbon in cis orientation
toward platinum, showing the occurrence of cis insertion
of dimethyl acetylenedicarboxylate into the Pt-Sn bond
of 1b.
F igu r e 5. Time course of the reaction of 1b with phenyl-
acetylene in CD2Cl2 in the presence of added PMe2Ph at
-5.0 °C (plot a). Initial concentration: [1b]0 ) 20 mM,
[PhCtCH] ) 0.20 M, [PMe2Ph]0 ) 2.0 mM. Plot b repre-
sents the first-order plot for the conversion of 1b.
tive example of the time course. Complexes 2b and 3b
are simultaneously formed in the ratio of 30/70 through-
out the reaction. The conversion of 1b obeys good
pseudo-first-order kinetics at least for two half-lives
under the conditions using an excess amount of phenyl-
acetylene (see Figure 5b).9
(d ) Kin etic Stu d y. The reaction progress of 1b with
phenylacetylene in CD2Cl2 at -5.0 °C was followed by
1H NMR spectroscopy at several concentrations of PhCt
CH and added PMe2Ph. Figure 5a shows a representa-
Table 4 lists the rate constants observed under
various conditions. The reaction proceeded more rapidly

4438 Organometallics, Vol. 22, No. 22, 2003
Sagawa et al.
Sch em e 5a
Ta ble 4. Kin etic Da ta for th e Rea ction of 1b w ith
P h en yla cetylen e
b
runa
[PhCtCH]0 (M)
[PMe2Ph]0 (mM)
103kobsd (s-1
)
1
2
3
4
5
6
7
8
0.20
0.15
0.20
0.30
0.58
0.30
0.30
0.30
2.0
2.5
2.5
2.5
2.5
15
1.50(1)
0.755(1)
1.15(1)
1.75(2)
3.14(3)
0.595(1)
0.455(1)
0.324(1)
22
30
a
L ) PMe2Ph.
a
All runs were performed in CD2Cl2 at -5.0 °C in the presence
of added PMe2Ph. Initial concentration: [1b]0 ) 20 (run 1) or 25
b
mM (runs 2-8). Rate constants for the conversion of 1b, esti-
to the system. Furthermore, the following crossover
experiments have suggested an intramolecular process
for the conversion. Thus, the kinetic mixture of 2b and
3b (30/70), generated in situ from 1b and PhCtCH (1
equiv) in CD2Cl2 in the presence of free PMe2Ph (0.1
equiv) at -5 °C, was treated with p-MeC6H4CtCH (3
equiv) at 35 °C for 3 h (Scheme 5). NMR examination
of the resulting reaction solution revealed selective
conversion of 2b to 3b; no trace of the insertion product
of p-MeC6H4CtCH (3i) was detected. Similarly, heating
a kinetic mixture of 2i and 3i (28/72) with PhCtCH (3
equiv) in CD2Cl2 at 35 °C for 3 h led to selective
formation of 3i.
mated by least-squares treatment of first-order plots at least for
two half-lives.9
Discu ssion
Mech a n ism of Alk yn e In ser tion . The kinetic ob-
servations for 1b are consistent with the insertion
mechanism given in Scheme 6. The first step is associa-
tive displacement of one of the phosphine ligands (L)
in 1 with alkyne to give 4 and 5, which are very probably
interconverted with each other by twist-rotation simi-
larly to 1 (Scheme 3). The rate of twist-rotation for 1b
was estimated to be 1.8 × 102 s-1 at -5 °C by line-shape
analysis of the 31P{1H} NMR spectrum, and this value
is about 105 greater than the rate of phenylacetylene
insertion into 1b. Although we had no direct information
about the rate of interconversion between 4 and 5, all
phenomena observed in this study have been found to
be reasonably interpreted by assuming the occurrence
of rapid equilibrium between these intermediates (vide
infra).
Complexes 4 and 5 undergo migratory insertion in the
next step. Stannyl migration in 4 gives a three-
coordinate intermediate 6, which is subsequently con-
verted to 2 by trans-to-cis isomerization followed by
coordination of L. On the other hand, silyl migration in
5 causes the formation of 3 via the intermediate 7.
F igu r e 6. (a) Plot of pseudo-first-order rate constants
against phenylacetylene concentration for the data of runs
2-5 in Table 4. (b) Plot of pseudo-first-order rate constants
against concentration of added PMe2Ph for the data of runs
4 and 6-8 in Table 4.
When the interconversion between 4 and 5 is rapid
enough to keep the ratio of 4 to 5 constant, and the
steady-state approximation can be applied to the total
concentration of 4 and 5, the following relation holds:
at higher concentration of phenylacetylene (runs 2-5).
The plot of kobsd against [PhCtCH]0 gave a straight line
including the origin (Figure 6a). On the other hand, the
reaction was retarded by addition of free PMe2Ph to the
system (runs 4 and 6-8, and Figure 6b).
(k1Sn + k1Si)[R′CtCH][1] )
(e) Con ver sion of 2 to 3. We have described that 2
formed under kinetic conditions is subsequently con-
verted to 3 under thermodynamic conditions. This
reaction is clearly retarded by addition of free phosphine
(k-1Sn[4] + k-1Si[5])[L] + (k2Sn[4] + k2Si[5]) (1)
Since [5] ) K[4],
(k1Sn + k1Si)[R′CtCH][1] )
(9) The kobsd values of runs 2 and 3 in Table 4 were derived from
the first-order plots of the data up to 58% and 76% conversion of 1b,
respectively.
{(k-1Sn + k-1SiK)[L] + (k2Sn + k2SiK)}[4] (2)

Alkyne Insertion into cis-Silyl(stannyl) Pt(II)
Organometallics, Vol. 22, No. 22, 2003 4439
Sch em e 6
Accordingly,
and (k-1Sn + k-1SiK)/(k2Sn + k2SiK) values were estimated
as 0.94(1) × 10-2 s-1 M-1 and 2.5(1) × 102, respectively.
Effect of Silyl a n d P h osp h in e Liga n d s. (a ) Rea c-
tion Ra te. Based on the kinetic analysis described
above, the overall rate of the conversion of 1 to 2 and 3
is considered to be controlled at two stages. One is
associative displacement of one of the phosphine ligands
in 1 with alkyne, and the other is migratory insertion
of the alkyne ligands in 4 and 5 into Pt-Sn and Pt-Si
bonds, respectively. As seen from Table 2, variation in
the rate constants is particularly remarkable for the
change of silyl ligands. This tendency is rationalized by
assuming the latter stage to be more crucial for control-
ling the reaction rate, and this assumption is consistent
(k1Sn + k1Si)[R′CtCH]
[4] )
[1] (3)
(k-1Sn + k-1SiK)[L] + (k2Sn + k2SiK)
On the other hand, if the conversions of 6 to 2 and 7 to
3 are sufficiently faster than the migratory insertion in
4 and 5, the sum of the formation rates of 2 and 3 (i.e.,
the rate of conversion of 1) can be expressed as follows:
d[2] d[3]
d[1]
dt
+
) -
) k2Sn[4] + k2Si[5] )
(k2Sn + k2SiK)[4] (4)
dt
dt
with the balance of the rate constants for 1b: (k-1Sn
+
Substitution of eq 3 into eq 4 yields the following rate
expression:
k-1SiK)/(k2Sn + k2SiK) ) 2.5(1) × 102. Thus, reflecting
increase in Pt-Si bond energy,10 the rate of migratory
insertion in 5 may be reduced in the order SiMe3 (1a )
> SiMe2Ph (1b) > SiMePh2 (1c) > SiPh3, causing a drop
in the overall rate. As we discuss later, this point is also
related to the marked dependence of the kinetic ratio
of 2 to 3 on silyl ligands.
(k1Sn + k1Si)(k2Sn + k2SiK)[R′CtCH]
d[1]
-
)
[1] (5)
dt
(k-1Sn + k-1SiK)[L] + (k2Sn + k2SiK)
Thus, the kobsd value is correlated with the concentra-
tions of R′CtCH and L by the following equation:
The data in Table 2 also suggest that bulkiness of silyl
and phosphine ligands serves as another factor to
control the reactivity. Thus, it seems reasonable that
bulky ligands prevent the association of alkyne with 1
to retard the formation of 4 and 5, although the
possibility that the rates of migratory insertion in 4 and
5 are also reduced by steric factors cannot be excluded.
(b) Kin etic Ra tio. The kinetic ratio of 2 to 3 may be
dictated by two factors. One is the ratio of 4 to 5, and
the other is the relative rates of migratory insertion (i.e.,
k2Sn vs k2Si). As seen from the data of runs 1-4 in Table
2, the kinetic ratio of 2 to 3 remarkably increases in
the order 1a < 1b < 1c < 1d . Since these complexes
have the same ligands except for silyl ligands, the
dramatic change in the kinetic ratio is attributed to the
nature of silyl ligands.
[R′CtCH]
)
kobsd
(k-1Sn + k-1SiK)[L]
(k1Sn + k1Si)(k2Sn + k2SiK) (k1Sn + k1Si
1
+
(6)
)
Figure 7 shows the plot of [PhCtCH]0/kobsd values
against [PMe2Ph]0 values for all runs in Table 4, giving
a good linear correlation (r ) 0.998) fully consistent with
eq 6. Based on the intercept and slope, the (k1Sn + k1Si
)
As for the equilibrium between 4 and 5, the highly
electron-releasing SiMe3 ligand may coordinate most
preferentially to the position trans to the alkyne ligand
in 4, rather than the position trans to the phosphine
ligand in 5, to reduce electronic repulsion between trans
ligands. On the other hand, the bulky SiPh3 ligand will
be most favorably accommodated at the position cis to
the alkyne ligand in 5, rather than the position cis to
the phosphine ligand in 4, to avoid steric hindrance
(10) Generally, electron-withdrawing substituents on silicon lead to
strengthening of Pt-Si bonds: (a) Sakaki, S.; Mizoe, N.; Sugimoto,
M. Organometallics 1998, 17, 2510. (b) Sakaki, S.; Mizoe, N.; Sugimoto,
M.; Musashi, Y. Coord. Chem. Rev. 1999, 190-192, 933.
F igu r e 7. Plot of [PhCtCH]0/kobsd values against [PMe2-
Ph]0 values for all data in Table 4.

4440 Organometallics, Vol. 22, No. 22, 2003
Sagawa et al.
Sch em e 7
between the silyl and phosphine ligands. Accordingly,
the ratio of 4 to 5 is expected to decrease in the order
SiMe3 (1a ) > SiMe2Ph (1b) > SiMePh2 (1c) > SiPh3 (1d )
from both electronic and steric viewpoints. Since this
order is just the reverse of the sequence of kinetic ratios
actually observed, the marked variation in the kinetic
ratios for 1a -d must be considered to mainly reflect
the other factor, i.e., the difference in the insertion rates
in 4 and 5. Since the Pt-Si bond becomes stronger in
the order SiMe3 (1a ) < SiMe2Ph (1b) < SiMePh2 (1c) <
SiPh3 (1d ),10 the rate of migratory insertion in 5 should
be reduced in this order, and as a result, the product
ratio of 2 increases.
Comparing the product ratios for runs 2 and 5-7 in
Table 2, there is a tendency that the ratio of 3 increases
as the phosphine ligand becomes bulkier. Since the
complexes employed in these runs (1b and 1e-g) have
the same silyl and stannyl ligands, it seems likely that
all complexes adopt a very similar balance of migratory
insertion rates. Consequently, the modest variation in
the product ratio is attributable mainly to a change in
the equilibrium position between 4 and 5 dependent on
the bulkiness of phosphine ligands. As already seen for
the X-ray structure of 1d , the Pt-Sn bond is more
flexible than the Pt-Si bond. Moreover, the Pt-Sn bond
is significantly longer than the Pt-Si bond. Therefore,
it is likely that steric hindrance takes place more
remarkably between the silyl and phosphine ligands
than between the stannyl and phosphine ligands. This
situation causes shift of the equilibrium position toward
5 as the phosphine ligand becomes bulkier, and hence
the kinetic ratio of 3 increases.
and phosphine ligands (2A). Dissociation of phosphine
followed by â-stannyl group elimination from the result-
ing 2B forms an alkyne-coordinated silyl(stannyl) in-
termediate (8A), which is in an equilibrium with 8B as
a rotational isomer of the alkyne ligand. Migration of
the silyl group on the alkyne ligand in 8B affords 3B,
which undergoes phosphine coordination to give 3A ()
3). It should be noted that intermediates 8A and 8B
have the silyl and stannyl ligands in mutually trans
positions, and they are different from 4 and 5 in Scheme
6. Accordingly, the conversion of 2 into 3 under ther-
modynamic conditions is operative independent of the
alkyne insertion into 1 under kinetic conditions.
Con clu sion s
Effect of Alk yn es. A dramatic change in the kinetic
ratio of 2 to 3 has also been noted for the insertion of
five kinds of alkynes into 1b (Table 3). Thus, more
electron-deficient alkynes tend to insert more preferably
into the Pt-Sn bond. Since the overall rate of the
insertion is enhanced at the same time, it is considered
that electron-deficient alkynes mainly accelerate the
insertion into the Pt-Sn bond.
As already pointed out for a related palladium
system,4a the insertion into the Pt-Sn bond may be
disadvantageous over the insertion into the Pt-Si bond
in a thermodynamic sense because the C-Sn bond
generated in the former process is weaker than the
C-Si bond formed in the latter process. However, when
the Pt-C bond simultaneously formed in the alkyne
insertion is sufficiently strong to compensate the ener-
getically unfavorable situation associated with the
weaker C-Sn bond, the relative ease of the insertions
in 4 and 5 may be reversed by a kinetic reason
originating from the weaker Pt-Sn bond than the Pt-
Si bond, which makes the migration of the SnMe3 group
easier than that of the SiMe2Ph group. The results in
Table 3 should be the case where more electron-
withdrawing substituents provide stronger Pt-C bonds
in the insertion complexes.
We have succeeded for the first time in observing
details of the alkyne insertion into cis-silyl(stannyl)-
platinum(II) complexes having two tertiary phosphine
ligands (1). The reactions consist of competitive inser-
tion of alkynes into the Pt-Sn and Pt-Si bonds, giving
the corresponding insertion complexes 2 and 3, respec-
tively, and the subsequent conversion of 2 to 3 as
thermodynamic products. The ratio of 2 to 3 under
kinetic conditions is significantly affected by the types
of silyl and phosphine ligands and alkynes employed.
The variations thus observed have been reasonably
interpreted on the basis of the insertion mechanism
involving associative displacement of one of the phos-
phine ligands in 1 with alkynes, followed by competitive
migration of the stannyl and silyl ligands on the alkyne
ligand in the resulting 4 and 5, which are rapidly
interconverting with each other under reaction condi-
tions (Scheme 6).
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All manipulations were carried
out under a nitrogen atmosphere using conventional Schlenk
techniques. Nitrogen gas was dried by passage through P2O5
(Merck, SICAPENT). NMR spectra were recorded on a J EOL
J NM-A400 or Varian Mercury 300 spectrometer. Chemical
shifts are reported in δ (ppm) referenced to an external SiMe4
standard for 1H and 13C NMR and to an external 85% H3PO4
standard for 31P NMR. Et2O, pentane, and THF were dried
over sodium benzophenone ketyl and distilled prior to use.
CH2Cl2 was dried over CaH2 and distilled prior to use. CD2Cl2
was purified by passing through a short Al2O3 column and
Mech a n ism of t h e Con ver sion of 2 t o 3. It has
been suggested that the conversion of 2 to 3 proceeds
via an intramolecular process involving phosphine dis-
sociation. Scheme 7 illustrates our proposed mechanism.
As seen from the X-ray structure of 2k in Figure 4, the
alkenyl ligand in 2 is perpendicularly oriented toward
the coordination plane to avoid steric hindrance to silyl

Alkyne Insertion into cis-Silyl(stannyl) Pt(II)
Organometallics, Vol. 22, No. 22, 2003 4441
2
1
stored under a nitrogen atmosphere. Pt(cod)2 was prepared
according to the literature.11
) 8 and 5 Hz, J PtC ) 76 Hz, SiMe), 15.6 (dd, J PC ) 26 Hz,
2 1 3
3J PC ) 4 Hz, J PtC ) 41 Hz, PMe), 17.5 (d, J PC ) 24 Hz, J PC
2
) 4 Hz, J PtC ) 25 Hz, PMe), 126.5 (s, SiPh), 126.8 (s, SiPh),
P r ep a r a tion of cis-P t(SiP h 3)(Sn Me3)(P Me2P h )2 (1d ). To
a Schlenk tube containing Pt(cod)2 (503 mg, 1.22 mmol) and
Ph3SiSnMe3 (542 mg, 1.28 mmol) was added toluene (30 mL)
at 0 °C under a nitrogen atmosphere. Addition of PMe2Ph (337
mg, 2.44 mmol) to the system with stirring gave a reddish
brown solution, a part of which was transferred into an NMR
sample tube equipped with a rubber septum cap by cannula-
tion and examined by 31P{1H} NMR spectroscopy, showing the
quantitative formation of 1d . The solution was stirred at room
temperature for 1 h and then concentrated to almost dryness
by pumping. Et2O (3 mL) and pentane (5 mL) were added, and
the resulting yellow-brown solid was collected by filtration,
washed with pentane (2 mL × 3), and dried under vacuum.
Recrystallization of the crude product from a mixture of THF
and Et2O gave yellow crystals of 1d ‚THF, suitable for single-
crystal X-ray diffraction study (450 mg, 38%).
127.8 (d, 3J PC ) 9 Hz, PPh), 127.9 (d, 3J PC ) 9 Hz, PPh), 129.2
2
3
(s, PPh), 130.2 (dd, J PC ) 10 Hz, J PtP ) 16 Hz, PPh), 130.4
(dd, 2J PC ) 11 Hz, 3J PtP ) 13 Hz, PPh), 134.4 (s, 3J PtC ) 17 Hz,
1
3
SiPh), 139.4 (dd, J PC ) 41 Hz, J PC ) 7 Hz, PPh), 139.7 (dd,
1J PC ) 37 Hz, 3J PC ) 5 Hz, PPh), 151.6 (dd, 3J PC ) 9 and 7 Hz,
2J PtC ) 31 Hz, SiPh). 31P{1H} NMR (CD2Cl2, -50 °C): δ -6.1
2
1
2
2
119
117
(d, J PP ) 26 Hz, J PtP ) 1526 Hz, J
) 194 Hz, J
)
SnP
SnP
184 Hz), -8.3 (d, 2J PP ) 26 Hz, 1J PtP ) 2379 Hz, J
) 1616
2
119
SnP
2
117
Hz,
J
) 1544 Hz). Anal. Calcd for C27H42P2SiSnPt: C,
42.09; H, 5.49. Found: C, 41.95; H, 4.23.
SnP
1
3
Com p lex 1c. H NMR (CD2Cl2, -50 °C): δ -0.19 (s, J PtH
2
2
) 6.4 Hz, J SnH ) 37.5 Hz, 9H, SnMe), 0.71 (d, J PH ) 8.7 Hz,
3J PtH ) 25.2 Hz, 6H, PMe), 0.81 (d, 2J PH ) 2.4 Hz, 3J PtH ) 30.6
2
3
Hz, 6H, SiMe), 1.26 (d, J PH ) 7.8 Hz, J PtH ) 18.6 Hz, 6H,
PMe), 7.1-7.5 (m, 16H, Ph), 7.63 (d, 3J HH ) 6.6 Hz, 4H, SiPh).
13C{1H} NMR (CD2Cl2, -50 °C): δ -2.7 (dd, J PC ) 11 and 4
3
1
3
Com p lex 1d . H NMR (CD2Cl2, -50 °C): δ -0.42 (s, J PtH
2
1
3
2
2
Hz, J PtC ) 71 Hz, J SnC ) 178 Hz, SnMe), 6.0 (dd, J PC ) 7
) 6.8 Hz, J SnH ) 38.7 Hz, 9H, SnMe), 0.57 (d, J PH ) 9.0 Hz,
and 3 Hz, 2J PtC ) 82 Hz, SiMe), 15.4 (dd, 1J PC ) 26 Hz, 3J PC
)
3J PtH ) 24.6 Hz, 6H, PMe), 1.27 (d, 2J PH ) 7.8 Hz, 3J PtH ) 19.8
2
1
3
3
3 Hz, J PtC ) 36 Hz, PMe), 17.5 (dd, J PC ) 24 Hz, J PC ) 4
Hz, 6H, PMe), 7.1-7.7 (m, 19H, Ph), 7.82 (d, J HH ) 7.2 Hz,
2
3
6H, SiPh). 13C{1H} NMR (CD2Cl2, -50 °C): δ -3.4 (dd, 3J PC
)
Hz, J PtC ) 25 Hz, PMe), 127.0 (s, SiPh), 128.1 (d, J PC ) 8
2
2
2
1
Hz, PPh), 130.1 (d, J PC ) 10 Hz, PPh), 130.2 (d, J PC ) 11
11 and 4 Hz, J PtC ) 66 Hz, J SnC ) 181 Hz, SnMe), 14.6 (dd,
3
1
1J PC ) 26 Hz, J PC ) 3 Hz, J PtC ) 34 Hz, PMe), 17.0 (dd, J PC
3
2
1
Hz, PPh), 135.5 (s, J PtC ) 19 Hz, SiPh), 139.9 (dd, J PC ) 38
3
1
3
3
2
Hz, J PC ) 5 Hz, PPh), 140.1 (dd, J PC ) 42 Hz, J PC ) 7 Hz,
) 24 Hz, J PC ) 4 Hz, J PtC ) 25 Hz, PMe), 126.8 (s, SiPh),
PPh), 149.0 (t, 3J PC ) 7 Hz, 2J PtC ) 40 Hz, SiPh). 31P{1H} NMR
3
127.0 (s, SiPh), 128.0 (d, J PC ) 9 Hz, PPh), 129.3 (s, PPh),
2
1
2
2
(CD2Cl2, -50 °C): δ -6.4 (d, J PP ) 25 Hz, J PtP ) 1606 Hz,
) 187 Hz,
J PtP ) 2352 Hz, J
Calcd for C32H44P2SiSnPt: C, 46.17; H, 5.33. Found: C, 45.93;
H, 5.13.
129.7 (d, J PC ) 10 Hz, PPh), 129.8 (d, J PC ) 10 Hz, PPh),
2
1
2
2
3
1
3
119
117
J
J
) 181 Hz), -9.8 (d, J PP ) 25 Hz,
136.6 (s, J PtC ) 24 Hz, SiPh), 139.4 (dd, J PC ) 40 Hz, J PC
)
SnP
SnP
2
2
1
3
119
117
) 1561 Hz, J
) 1510 Hz). Anal.
5 Hz, PPh), 139.9 (dd, J PC ) 41 Hz, J PC ) 6 Hz, PPh), 145.6
SnP
SnP
3
2
(t, J PC ) 6 Hz, J PtC ) 46 Hz, SiPh). 31P{1H} NMR (CD2Cl2,
2
1
2
119
-50 °C): δ -5.4 (d, J PP ) 25 Hz, J PtP ) 1663 Hz, J
)
SnP
2
185 Hz, J
) 177 Hz), -9.7 (d, 2J PP ) 25 Hz, 1J PtP ) 2331
1
3
117
Com p lex 1e. H NMR (CD2Cl2, -50 °C): δ -0.01 (s, J PtH
SnP
2
2
2
4
119
117
Hz,
J
) 1559 Hz,
J
) 1499 Hz). Anal. Calcd for
) 6.6 Hz, J SnH ) 36.0 Hz, 9H, SnMe), 0.40 (d, J PH ) 2.7 Hz,
SnP
SnP
3J PtH ) 25.2 Hz, 6H, SiMe), 1.21 (d, J PH ) 8.4 Hz, J PtH
)
2
3
C
37H46P2SiSnPt‚C4H8O: C, 50.94; H, 5.63. Found: C, 50.90;
H, 5.42.
Complexes 1a -c, 1f, and 1g were similarly obtained in 86%
2
3
24.6 Hz, 9H, PMe), 1.54 (d, J PH ) 8.1 Hz, J PtH ) 16.8 Hz,
9H, PMe), 7.1-7.3 (m, 3H, Ph), 7.44-7.56 (m, 2H, Ph). 13C-
3
(1a ), 56% (1b), 64% (1c), 78% (1f), and 74% (1g) yields,
respectively. Complex 1e was prepared by essentially the same
procedure. Although the crude product contained a consider-
able amount of Pt(cod)(PMe3)2, this compound was removed
by washing with Et2O and pentane at room temperature.
Recrystallization of the resulting product formed analytically
pure 1e (35%).
{1H} NMR (CD2Cl2, -50 °C): δ -2.7 (dd, J PC ) 11 and 4 Hz,
1
3
2J PtC ) 71 Hz, J SnH ) 182 Hz, SnMe), 7.3 (dd, J PC ) 7 and 4
2
1
3
Hz, J PtC ) 75 Hz, SiMe), 18.5 (dd, J PC ) 28 Hz, J PC ) 6 Hz,
2J PtC ) 23 Hz, PMe), 19.6 (dd, 1J PC ) 24 Hz, 3J PC ) 4 Hz, 2J PtC
3
) 25 Hz, PMe), 126.5 (s, SiPh), 126.7 (s, SiPh), 134.5 (s, J PtC
) 17 Hz, SiPh), 151.6 (t, J PC ) 8 Hz, SiPh). 31P{1H} NMR
3
2
1
(CD2Cl2, -50 °C): δ -15.1 (d, J PP ) 27 Hz, J PtP ) 1464 Hz,
) 201 Hz, J
J PtP ) 2309 Hz, J
Calcd for C17H38P2SiSnPt: C, 31.59; H, 5.93. Found: C, 31.20;
H, 5.42.
Com p lex 1f. H NMR (CD2Cl2, -50 °C): δ -0.04 (s, J PtH
2
1
2
2
1
3
119
117
J
) 193 Hz), -17.8 (d, J PP ) 27 Hz,
Com p lex 1a . H NMR (CD2Cl2, -50 °C): δ 0.03 (s, J PtH
)
SnP
SnP
2
2
2
4
119
117
) 1645 Hz, J
) 1521 Hz). Anal.
6.9 Hz, J SnH ) 36.3 Hz, 9H, SnMe), 0.20 (d, J PH ) 2.4 Hz,
SnP
SnP
3J PtH ) 22.8 Hz, 9H, SiMe), 1.51 (d, J PH ) 6.6 Hz, J PtH
)
2
3
2
3
18.6 Hz, 6H, PMe), 1.54 (d, J PH ) 7.5 Hz, J PtH ) 27.0 Hz,
6H, PMe), 7.1-7.8 (m, 10H, Ph). 13C{1H} NMR (CD2Cl2, -50
1
3
3
2
1
2
3
°C): δ -2.1 (dd, J PC ) 11 and 5 Hz, J PtC ) 76 Hz, J SnC
)
) 8.7 Hz, J SnH ) 36.6 Hz, 9H, SnMe), 0.42 (s, J PtH ) 22.8
Hz, 6H, SiMe), 0.80 (br, 9H, PCH2CH3), 1.01 (br, 9H, PCH2CH3),
1.77 (br, 6H, PCH2CH3), 1.90 (br, 6H, PCH2CH3), 7.1-7.2 (m,
3H, Ph), 7.42 (m, 2H, Ph). 13C{1H} NMR (CD2Cl2, -50 °C): δ
3
2
181 Hz, SnMe), 9.0 (dd, J PC ) 7 and 6 Hz, J PtC ) 69 Hz,
1
3
2
SiMe), 18.1 (dd, J PC ) 26 Hz, J PC ) 7 Hz, J PtC ) 43 Hz,
PMe), 18.7 (dd, 1J PC ) 22 Hz, 3J PC ) 7 Hz, 2J PtC ) 30 Hz, PMe),
127.9 (d, 3J PC ) 9 Hz, PPh), 127.9 (d, 3J PC ) 8 Hz, PPh), 129.5
3
2
1
-1.9 (t, J PC ) 7 Hz, J PtC ) 75 Hz, J SnC ) 160 Hz, SnMe),
2
3
2
3
(s, PPh), 129.7 (s, PPh), 131.2 (d, J PC ) 12 Hz, PPh), 131.4
7.8 (dd, J PC ) 6 and 5 Hz, J PtC ) 73 Hz, SiMe), 8.7 (d, J PC
2
1
3
1
(d, J PC ) 11 Hz, PPh), 138.5 (dd, J PC ) 37 Hz, J PC ) 7 Hz,
) 9 Hz, PCH2CH3), 18.6 (br, PCH2CH3), 20.1 (br d, J PC ) 18
PPh), 139.1 (dd, 1J PC ) 32 Hz, 3J PC ) 6 Hz, PPh). 31P{1H} NMR
3
Hz, PCH2CH3), 126.4 (s, SiPh), 126.8 (s, SiPh), 133.8 (s, J PtC
2
1
3
2
(CD2Cl2, -50 °C): δ -5.3 (d, J PP ) 28 Hz, J PtP ) 1419 Hz,
) 14 Hz, SiPh), 152.1 (t, J PC ) 8 Hz, J PtC ) 31 Hz, SiPh).
2
1
2
2
31P{1H} NMR (CD2Cl2, -50 °C): δ 14.5 (br d, J PP ) 23 Hz,
2
119
117
J
) 196 Hz,
J
) 192 Hz), -5.7 (d, J PP ) 28 Hz,
SnP
SnP
2
2
1J PtP ) 1629 Hz, J SnP ) 185 Hz), 13.6 (br d, J PP ) 23 Hz,
2
2
119
117
J PtP ) 2392 Hz, J
) 1634 Hz, J
) 1577 Hz). Anal.
SnP
SnP
1J PtP ) 2513 Hz, J SnP ) 1616 Hz). Anal. Calcd for C23H50P2-
2
Calcd for C22H40P2SiSnPt: C, 37.30; H, 5.69. Found: C, 37.65;
H, 5.43.
SiSnPt: C, 37.82; H, 6.90. Found: C, 37.54; H, 6.93.
Com p lex 1g. H NMR (CD2Cl2, -50 °C): δ -0.27 (s, J PtH
1
3
1
3
Com p lex 1b. H NMR (CD2Cl2, -50 °C): δ -0.01 (s, J PtH
2
4
2
3
) 7.5 Hz, J SnH ) 36.6 Hz, 9H, SnMe), 0.45 (d, J PH ) 2.4 Hz,
) 7.5 Hz, J SnH ) 37.8 Hz, 9H, SnMe), 0.25 (s, J PtH ) 22.8
Hz, 6H, SiMe), 1.31 (br, 3H, PMe), 1.50 (br, 3H, PMe), 7.2-
7.8 (m, 25H, Ph). 13C{1H} NMR (CD2Cl2, -50 °C): δ -2.6 (t,
3J PtH ) 26.1 Hz, 6H, SiMe), 0.91 (d, J PH ) 8.7 Hz, J PtH
)
2
3
2
3
25.5 Hz, 6H, PMe), 1.30 (d, J PH ) 7.5 Hz, J PtH ) 18.6 Hz,
3
3J PC ) 7 Hz, J PtC ) 75 Hz, SnMe), 7.2 (t, J PC ) 6 Hz, J PtC
)
2
3
2
6H, PMe), 7.1-7.5 (m, 13H, Ph), 7.56 (d, J HH ) 6.9 Hz, 2H,
SiPh). 13C{1H} NMR (CD2Cl2, -50 °C): δ -2.5 (dd, J PC ) 11
3
67 Hz, SiMe), 13.9 (br, PMe), 14.1 (br, PMe), 126.7 (s, SiPh),
127.8 (d, 3J PC ) 8 Hz, PPh), 129.3 (s, PPh), 131.6 (d, 2J PC ) 10
Hz, PPh), 134.6 (s, 3J PtC ) 18 Hz, SiPh), 137.6 (br, PPh), 138.1
2
1
3
and 4 Hz, J PtC ) 75 Hz, J SnC ) 179 Hz, SnMe), 7.2 (dd, J PC
3
2
(11) Crascall, L. E.; Spencer, J . L. Inorg. Synth. 1990, 28, 126.
(br, PPh), 150.6 (t, J PC ) 6 Hz, J PtC ) 27 Hz, SiPh). 31P{1H}

4442 Organometallics, Vol. 22, No. 22, 2003
Sagawa et al.
NMR (CD2Cl2, -50 °C): δ 9.3 (br d, 2J PP ) 21 Hz, 1J PtP ) 1596
Hz, J SnP ) 197 Hz), 6.2 (br d, J PP ) 21 Hz, J PtP ) 2461 Hz,
2J SnP ) 1540 Hz). Anal. Calcd for C37H46P2SiSnPt: C, 49.68;
H, 5.18. Found: C, 49.53; H, 5.20.
3J PtH ) 30.0 Hz, 3H, PMe), 1.02 (d, 2J PH ) 8.7 Hz, 3J PtH ) 32.3
2
2
1
2
3
Hz, 3H, PMe), 1.20 (d, J PH ) 7.8 Hz, J PtH ) 28.2 Hz, 3H,
2 3
PMe), 1.65 (d, J PH ) 8.1 Hz, J PtH ) 35.7 Hz, 3H, PMe), 6.67
(t, 2H, Ph), 7.04 (t, 2H, Ph), 7.1-7.4 (m, 17H, Ph), 7.67 (d,
4
6H, Ph), 7.84 (d, 2H, Ph), 8.08 (dd, J PH ) 19.5 and 4.2 Hz,
Rea ction of 1d w ith P h en yla cetylen e. The time course
of the reaction of 1d with phenylacetylene shown in Figure 3
3J PtH ) 96.9 Hz, 1H, PtCdCH). 13C{1H} NMR (CD2Cl2, 20 °C):
δ -3.8 (d, 3J PC ) 10 Hz, 2J PtC ) 74 Hz, 1J SnC ) 183 Hz, SnMe),
12.8 (d, 1J PC ) 26 Hz, 2J PtC ) 26 Hz, PMe), 14.5 (dd, 1J PC ) 30
1
was followed by H NMR spectroscopy. For example, 1d (10.8
mg, 12.1 µmol) was placed in an NMR sample tube equipped
with a rubber septum cap and dissolved in CDCl3 (0.6 mL) at
room temperature. Dimethylphenylphosphine (1.7 µL, 11.9
µmol) and phenylacetylene (13 µL, 0.12 mmol) were added,
and the sample tube was placed in an NMR sample probe
controlled at 50 °C. Relative amounts of 1d , 2d , and 3d at
time t were determined by peak integration of the SnMe3
signals, which appeared at δ -0.31 (1d ), 0.22 (2d ), and -0.26
(3d ), respectively, in the 1H NMR spectrum at 50 °C.
3
2
1
Hz, J PC ) 3 Hz, J PtH ) 36 Hz, PMe), 18.4 (dd, J PC ) 30 Hz,
3J PC ) 7 Hz, J PtH ) 17 Hz, PMe), 20.1 (dd, J PC ) 33 Hz, J PC
3
1
3
3
3
2
) 5 Hz, J PtH ) 50 Hz, PMe), 125.8 (t, J PC ) 6 Hz, J PtC ) 56
Hz, PtCdCH), 126.6 (s, 5J PtC ) 4 Hz, Ph), 127.8 (s, SiPh), 127.8
3
3
(s, Ph), 128.3 (d, J PC ) 8 Hz, PPh), 128.3 (d, J PC ) 10 Hz,
PPh), 129.2 (s, SiPh), 129.4 (s, Ph), 129.7 (s, PPh), 129.9 (s,
2
3
PPh), 130.5 (d, J PC ) 10 Hz, J PtC ) 10 Hz, PPh), 131.5 (d,
2J PC ) 10 Hz, J PtC ) 20 Hz, PPh), 137.1 (s, SiPh), 138.4 (s,
3
3
2
SiPh), 154.1 (d, J PC ) 3 Hz, J PtC ) 33 Hz, Ph), 184.3 (dd,
2J PC ) 101 and 13 Hz, 1J PtH ) 719 Hz, PtCdCH). The two ipso
carbon signals of PPh groups at δ 138-139 were obscured. 31P-
Id en t ifica t ion of cis-P t {C(P h )dCH (Sn Me3)}(SiP h 3)-
(P Me2P h )2 (2d ). Complex 3d was independently prepared and
identified by NMR spectroscopy and elemental analysis (vide
infra). On the other hand, since 2d is readily converted to 3d
in neat solvents, its formation was confirmed by NMR spec-
troscopy without isolation. The sample solution was prepared
by the treatment of 1d (20.5 mg, 22.9 µmol) with phenylacety-
lene (2.5 µL, 26.3 µmol) in CD2Cl2 (0.6 mL) in the presence of
PMe2Ph (3.2 µL, 22 µmol). Heating the sample at 35 °C for 1
day led to a solution containing a 93/7 ratio of 2d and 3d . The
following NMR signals were observed for 2d , clearly distinct
from the peaks of free PMe2Ph and 3d . Thus, the vinylic proton
signal appeared at δ 8.46 as a doublet of doublets (J PH ) 5.4
and 3.9 Hz) with the satellites arising from H-Sn couplings
{1H} NMR (CD2Cl2, 20 °C): δ -15.3 (d, J PP ) 18 Hz, J PtP
)
2
1
2
2
119
117
2081 Hz, J
) 1736 Hz, J
) 1659 Hz), -18.6 (d, 2J PP
SnP
SnP
) 18 Hz, 1J PtP ) 1975 Hz, J
) 171 Hz, J
) 164 Hz).
2
2
119
117
SnP
SnP
Anal. Calcd for C45H52P2SiSnPt: C, 54.23; H, 5.26. Found: C,
53.95; H, 5.19.
Id en tifica tion of 2. Complexes 2b, 2c, and 2e-j were
prepared similarly to 2d and characterized by NMR spectros-
copy without isolation. The 31P{1H} NMR spectra exhibited
two sets of doublets with small (1181-1302 Hz) and moderate
(1825-2000 Hz) couplings to platinum, respectively. These
1J PtP values were consistent with the structures having alkenyl
and silyl ligands in mutually cis positions, as already seen for
2d . Since the selectivities for these complexes were much lower
than that for 2d , a rather limited number of 1H NMR signals
were assignable, while the â-vinylic proton signals were clearly
detected at a significantly lower magnetic field (δ 8.25-9.07)
2
2
119
117
(224 Hz, the mean value of the
J
and
J
SnH). The
SnH
observed coupling constants were consistent with the arrange-
ment of atoms in the (PhMe2P)2PtC(Ph)dCHSnMe3 moiety.
On the other hand, in the 13C{1H} NMR spectrum, the
R-vinylic carbon signal was observed at δ 169.4 as a doublet
of doublets with platinum satellites (2J PC ) 99 and 17 Hz, 1J PtC
) 713 Hz), which disappeared in a DEPT NMR spectrum
because of the absence of a proton on this carbon. The 31P-
{1H} NMR signals did not involve P-Sn couplings, showing
4
with J PH values (4-5 Hz) comparable to 2d .
Com p lex 2b. 1H NMR (CD2Cl2, -5 °C): δ 0.23 (s, 6H,
4
SiMe), 0.24 (s, 9H, SnMe), 8.68 (dd, J PH ) 4.5 and 4.2 Hz,
1H, PtCdCH). 31P{1H} NMR (CD2Cl2, -5 °C): δ -11.7 (d, 2J PP
1
1
2
1
the absence of a Pt-Sn bond. The J PtP values were consistent
) 18 Hz, J PtP ) 1193 Hz), -15.3 (d, J PP ) 18 Hz, J PtP
)
with the alkenyl(silyl)platinum(II) structure.
Com p lex 2d . H NMR (CD2Cl2, 20 °C): δ 0.19 (s, J
1868 Hz).
1
2
119
Com p lex 2c. 1H NMR (CD2Cl2, -5 °C): δ 0.30 (s, 9H,
)
SnH
2
) 48.0 Hz, 9H, SnMe), 0.89 (d, 2J PH ) 8.0 Hz,
117
4
52.0 Hz, J
SnH
SnMe), 0.31 (s, 3H, SiMe), 8.51 (dd, J PH ) 5.4 and 3.9 Hz,
3J PtH ) 24.0 Hz, 3H, PMe), 1.20 (d, 2J PH ) 8.0 Hz, 3J PtH ) 16.0
3J PtH ) 14 Hz, J SnH ) 213 Hz, 1H, PtCdCH). 31P{1H} NMR
2
2
3
2
1
Hz, 3H, PMe), 1.33 (d, J PH ) 8.0 Hz, J PtH ) 24.0 Hz, 3H,
(CD2Cl2, -5 °C): δ -9.1 (d, J PP ) 18 Hz, J PtP ) 1302 Hz),
2
3
2
1
PMe), 1.42 (d, J PH ) 8.0 Hz, J PtH ) 16.0 Hz, 3H, PMe), 8.46
-14.2 (d, J PP ) 18 Hz, J PtP ) 1966 Hz).
(dd, 4J PH ) 5.4 and 3.9 Hz, 3J PtH ) 14 Hz, 2J SnH ) 224 Hz, 1H,
Com p lex 2e. 1H NMR (CD2Cl2, -5 °C): δ 0.23 (s, 9H,
PtCdCH). 13C{ H} NMR (CD2Cl2, 20 °C): δ -6.0 (s, J
)
1
1
119
SnC
4
SnMe), 0.24 (s, 6H, SiMe), 8.73 (t, J PH ) 4.8 Hz, 1H, PtCd
1
414 Hz, J SnC ) 304 Hz, SnMe), 12.0 (d, 1J PC ) 21 Hz, PMe),
117
CH). 31P{1H} NMR (CD2Cl2, -5 °C): δ -21.4 (d, 2J PP ) 18 Hz,
15.2 (d, 1J PC ) 30 Hz, 2J PtC ) 30 Hz, PMe), 16.7 (dd, 1J PC ) 26
1J PtP ) 1206 Hz), -28.2 (d, J PP ) 18 Hz, J PtP ) 1825 Hz).
2
1
3
2
1
Hz, J PC ) 5 Hz, J PtC ) 26 Hz, PMe), 17.6 (dd, J PC ) 29 Hz,
3J PC ) 5 Hz, 2J PtC ) 26 Hz, PMe), 137.1 (s, 3J PtC ) 21 Hz, SiPh),
Com p lex 2f. 1H NMR (CD2Cl2, -5 °C): δ 0.25 (s, 6H, SiMe),
0.27 (s, 9H, SnMe), 8.49 (t, J PH ) 4.5 Hz, 1H, PtCdCH). 31P-
4
3
2
3
144.7 (d, J PC ) 3 Hz, J PtC ) 53 Hz, SiPh), 152.7 (dd, J PC
)
{1H} NMR (CD2Cl2, -5 °C): δ -0.6 (d, J PP ) 20 Hz, J PtP
)
2
1
2
1
14 and 4 Hz, Ph), 169.4 (dd, J PC ) 99 and 17 Hz, J PtC ) 713
2
1
1201 Hz), 0.1 (d, J PP ) 20 Hz, J PtP ) 1875 Hz).
Hz, PtCdCH). 31P{1H} NMR (CD2Cl2, 20 °C): δ -10.9 (d, 2J PP
Com p lex 2g. 1H NMR (CD2Cl2, -5 °C): δ 0.33 (s, 6H,
1
2
1
) 19 Hz, J PtP ) 1324 Hz), -15.5 (d, J PP ) 19 Hz, J PtP
1889 Hz).
)
4
SiMe), 0.40 (s, 9H, SnMe), 8.25 (t, J PH ) 4.8 Hz, 1H, PtCd
CH). 31P{1H} NMR (CD2Cl2, -5 °C): δ 4.0 (d, J PP ) 16 Hz,
2
P r epar ation of cis-P t{C(P h )dCH(SiP h 3)}(Sn Me3)(P Me2-
P h )2 (3d ). Analytically pure 3d was obtained by the following
procedure. Complex 1d (150 mg, 0.168 mmol) was dissolved
in CH2Cl2 (5 mL), and phenylacetylene (79.6 mg, 0.779 mmol)
was added. The reddish yellow mixture was stirred at room
temperature for 24 h to give a pale yellow solution, which was
concentrated to almost dryness by pumping. Et2O (1 mL) and
pentane (3 mL) were added, and the resulting solid was
collected by filtration, washed with pentane (1 mL × 3), and
dried under vacuum. Recrystallization of the crude product
from a mixture of CH2Cl2 and Et2O gave white crystals of 3d
(102 mg, 61%).
1J PtP ) 1190 Hz), -0.6 (d, J PP ) 16 Hz, J PtP ) 1891 Hz).
2
1
Com p lex 2h . 1H NMR (CD2Cl2, -5 °C): δ 0.30 (s, 6H,
4
SiMe), 0.32 (s, 9H, SnMe), 3.49 (s, 2H, NH2), 8.53 (t, J PH
)
4.5 Hz, 1H, PtCdCH). 31P{1H} NMR (CD2Cl2, -5 °C): δ -11.4
2
1
2
(d, J PP ) 17 Hz, J PtP ) 1191 Hz), -15.6 (d, J PP ) 17 Hz,
1J PtP ) 1846 Hz).
Com p lex 2i. 1H NMR (CD2Cl2, -5 °C): δ 0.31 (s, 6H, SiMe),
4
0.33 (s, 9H, SnMe), 2.25 (s, 3H, p-Me), 8.78 (t, J PH ) 5.1 Hz,
1H, PtCdCH). 31P{1H} NMR (CD2Cl2, -5 °C): δ -11.7 (d, 2J PP
1
2
1
) 18 Hz, J PtP ) 1181 Hz), -15.6 (d, J PP ) 18 Hz, J PtP
)
1858 Hz).
1
3
Com p lex 3d . H NMR (CD2Cl2, 20 °C): δ -0.32 (s, J PtH
)
Com p lex 2j. 1H NMR (CD2Cl2, -5 °C): δ 0.33 (s, 6H, SiMe),
2
2
4.2 Hz, J SnH ) 37.5 Hz, 9H, SnMe), 0.83 (d, J PH ) 8.4 Hz,
0.37 (s, 9H, SnMe), 9.07 (t, 4J PH ) 3.9 Hz, 1H, PtCdCH), 10.0

Alkyne Insertion into cis-Silyl(stannyl) Pt(II)
Organometallics, Vol. 22, No. 22, 2003 4443
2
2
3
(s, 1H, CHO). 31P{1H} NMR (CD2Cl2, -5 °C): δ -9.3 (d, J PP
1.15 (d, J PH ) 8.1 Hz, J PtH ) 31.2 Hz, 3H, PMe), 1.48 (d,
1
2
1
3
2
) 20 Hz, J PtP ) 1224 Hz), -15.6 (d, J PP ) 20 Hz, J PtP
)
2J PH ) 7.8 Hz, J PtH ) 25.8 Hz, 3H, PMe), 1.58 (d, J PH ) 7.8
Hz, 3J PtH ) 27.6 Hz, 3H, PMe), 7.0-7.4 (m, 16H, Ph), 7.51 (dd,
4J PH ) 19.8 and 4.5 Hz, 1H, PtCdCH), 7.67 (m, 2H, Ph), 7.77
2000 Hz).
P r ep a r a tion of cis-P t{C(CO2Me)dC(CO2Me)(Sn Me3)}-
(SiMe2P h )(P Me2P h )2 (2k ). To a solution of 1b (80 mg, 0.10
mmol) in CH2Cl2 (5 mL) was added dimethyl acetylenedicar-
boxylate (30 mg, 0.21 mmol) at -50 °C. The initially pale
yellow color of the solution instantly changed to red. The
solvent was removed by pumping at 0 °C. The resulting oily
material was cooled to -78 °C and dissolved in Et2O (0.5 mL).
Addition of pentane (1 mL) with stirring led to precipitation
of a reddish orange powder, which was collected by filtration,
washed with pentane (1 mL × 2), and dried under vacuum
(73 mg, 77%). Analytically pure compound was obtained by
recrystallization from CH2Cl2 and Et2O.
(m, 2H, Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ -4.1 (dd, J PC
3
2
1
) 10 and 2 Hz, J PtC ) 78 Hz, J SnC ) 191 Hz, SnMe), 0.20 (s,
1
3
2
SiMe), 13.4 (dd, J PC ) 26 Hz, J PC ) 2 Hz, J PtC ) 27 Hz,
PMe), 14.5 (dd, 1J PC ) 29 Hz, 3J PC ) 3 Hz, 2J PtC ) 39 Hz, PMe),
1
3
1
18.8 (dd, J PC ) 17 Hz, J PC ) 5 Hz, PMe), 19.2 (dd, J PC ) 18
3
5
Hz, J PH ) 5 Hz, PMe), 126.2 (s, J PtC ) 6 Hz, Ph), 127.7 (s,
Ph), 127.9 (s, SiPh), 128.4 (d, 3J PC ) 9 Hz, PPh), 128.5 (s, SiPh),
3
4
3
128.5 (d, J PC ) 9 Hz, PPh), 129.4 (d, J PC ) 2 Hz, J PtC ) 45
4
4
Hz, Ph), 129.7 (d, J PC ) 2 Hz, PPh), 129.8 (d, J PC ) 2 Hz,
2
3
PPh), 130.8 (d, J PC ) 12 Hz, J PtC ) 14 Hz, PPh), 130.9 (d,
2J PC ) 12 Hz, J PtC ) 15 Hz, PPh), 134.4 (s, SiPh), 138.1 (dd,
3
1J PC ) 36 Hz, 3J PC ) 2 Hz, 2J PtC ) 17 Hz, PPh), 138.9 (dd, 1J PC
1
2
119
Com p lex 2k . H NMR (CD2Cl2, 20 °C): δ 0.54 (s, J
)
SnP
3
2
2
117
) 42 Hz, J PC ) 4 Hz, J PtC ) 15 Hz, PPh), 142.9 (s, SiPh),
54.0 Hz, J
) 51.6 Hz, 9H, SnMe), 0.56 (d, 4J PH ) 2.4 Hz,
2 3
SnH
3
2
3J PtH ) 19.8 Hz, 6H, SiMe), 1.07 (d, J PH ) 8.7 Hz, J PtH
)
153.4 (dd, J PC ) 5 and 2 Hz, J PtC ) 37 Hz, Ph), 178.8 (dd,
2J PC ) 100 and 14 Hz, PtCdCH). The â-vinylic carbon signal
was not assigned. 31P{1H} NMR (CD2Cl2, 20 °C): δ -14.0 (d,
2
3
26.4 Hz, 3H, PMe), 1.17 (d, J PH ) 8.4 Hz, J PtH ) 23.4 Hz,
2
3
3H, PMe), 1.43 (d, J PH ) 8.4 Hz, J PtH ) 15.6 Hz, 3H, PMe),
2J PP ) 17 Hz, J PtP ) 2071 Hz,
J
) 1771 Hz,
J
)
)
1
2
2
2
2
3
119
117
SnP
SnP
1.50 (d, J PH ) 8.4 Hz, J PtH ) 15.6 Hz, 3H, PMe), 3.70 (s, 6H,
2
1
119
CO2Me), 7.1-7.9 (m, 20H, Ph). 13C{1H} NMR (CD2Cl2, 20 °C):
1692 Hz), -16.7 (d, J PP ) 18 Hz, J PtP ) 1928 Hz, J
SnP
2
1
1
117
119
2
117
166 Hz,
J
) 159 Hz). Anal. Calcd for C35H48P2SiSnPt:
SnP
δ -6.0 (s, J
) 351 Hz, J
) 336 Hz, SnMe), 5.7 (d,
1 2
SnC
SnC
3J PC ) 7 Hz, J PtC ) 53 Hz, SiMe), 12.8 (d, J PC ) 25 Hz, J PtC
) 26 Hz, PMe), 15.1 (dd, 1J PC ) 32 Hz, 3J PC ) 3 Hz, 2J PtC ) 25
C, 48.18; H, 5.54. Found: C, 47.93; H, 5.44.
1
3
Com p lex 3c. H NMR (CD2Cl2, 20 °C): δ -0.20 (s, J PtH
)
2
Hz, PMe), 15.6 (dd, J PC ) 27 Hz, J PC ) 2 Hz,2J PtC ) 24 Hz,
PMe), 18.2 (dd, 1J PC ) 28 Hz, 3J PC ) 6 Hz, 2J PtC ) 45 Hz, PMe),
50.6 (s, CO2Me), 51.3 (s, CO2Me), 127.3 (s, SiPh), 128.4 (d, 3J PC
1
3
7.5 Hz, J SnH ) 37.8 Hz, 9H, SnMe), 1.03 (s, 3H, SiMe), 0.78
2
3
2
(d, J PH ) 8.4 Hz, J PtH ) 33.6 Hz, 3H, PMe), 0.86 (d, J PH
)
8.7 Hz, 3J PtH ) 33.6 Hz, 3H, PMe), 1.40 (d, 2J PH ) 8.1 Hz, 3J PtH
2
3
3
4
) 31.2 Hz, 3H, PMe), 1.44 (d, J PH ) 7.8 Hz, J PtH ) 25.8 Hz,
) 9 Hz, PPh), 128.5 (d, J PC ) 9 Hz, PPh), 129.8 (d, J PC ) 2
2
3
4
2
3H, PMe), 1.44 (d, J PH ) 7.8 Hz, J PtH ) 27.6 Hz, 3H, PMe),
Hz, PPh), 130.0 (d, J PC ) 2 Hz, PPh), 130.8 (d, J PC ) 11 Hz,
4
3J PtP ) 14 Hz, PPh), 131.2 (d, 2J PC ) 11 Hz, 3J PtP ) 7 Hz, PPh),
6.8-7.8 (m, 25H, Ph), 7.96 (dd, J PH ) 19.2 and 4.5 Hz, 1H,
PtCdCH). 13C{1H} NMR (CD2Cl2, 20 °C): δ -4.2 (d, 3J PC ) 10
3
2
3
132.5 (t, J PC ) 13 Hz, J PtC ) 27 Hz, PtCdC), 134.7 (s, J PtC
Hz, 2J PtC ) 77 Hz, 1J SnC ) 193 Hz, SnMe), -1.5 (s, SiMe), 12.9
1
3
) 9 Hz, SiPh), 137.8 (dd, J PC ) 44 Hz, J PC ) 5 Hz, PPh),
1
2
1
1
3
3
(d, J PC ) 25 Hz, J PtC ) 27 Hz, PMe), 14.6 (dd, J PC ) 30 Hz,
137.9 (dd, J PC ) 39 Hz, J PC ) 5 Hz, PPh), 150.6 (dd, J PC
)
3J PC ) 3 Hz, J PtC ) 41 Hz, PMe), 18.8 (dd, J PC ) 31 Hz, J PC
2
1
3
2
3
7 and 3 Hz, J PtC ) 45 Hz, SiPh), 168.8 (dd, J PC ) 14 and 4
) 4 Hz, PMe), 19.0 (dd, 1J PC ) 31 Hz, 3J PC ) 6 Hz, PMe), 125.0
4
Hz, PtC(CO2Me)dC), 177.3 (d, J PC ) 3 Hz, PtCdC(CO2Me)),
3
2
5
193.9 (dd, J PC ) 98 and 15 Hz, PtCdC). 31P{1H} NMR (CD2-
2
(t, J PC ) 6 Hz, J PtC ) 55 Hz, PtCdCH), 126.5 (s, J PtC ) 4
Hz, Ph), 127.7 (s, Ph), 127.8 (s, SiPh), 128.0 (s, SiPh), 128.4
2
1
Cl2, 20 °C): δ -10.9 (d, J PP ) 21 Hz, J PtP ) 1203 Hz), -16.4
(d, 2J PP ) 21 Hz, 1J PtP ) 2168 Hz). Anal. Calcd for C33H48O4P2-
SiSnPt: C, 43.43; H, 5.30. Found: C, 43.41; H, 5.31.
P r ep a r a tion of 3. The complexes resulting from alkyne
insertion into the Pt-Si bond of 1 were prepared similarly to
3d in 60% (3a ), 67% (3b), 52% (3c), 82% (3e), 76% (3f), 48%
(3g), 62% (3h ), 72% (3i), and 55% (3j) yields, respectively.
3
3
(d, J PC ) 8 Hz, PPh), 128.5 (d, J PC ) 9 Hz, PPh), 128.7 (s,
4
3
SiPh), 128.9 (s, SiPh), 129.5 (d, J PC ) 2 Hz, J PtC ) 48 Hz,
Ph), 129.7 (s, PPh), 129.9 (s, PPh), 130.7 (d, 2J PC ) 11 Hz, 3J PtC
2
3
) 15 Hz, PPh), 130.9 (d, J PC ) 12 Hz, J PtC ) 15 Hz, PPh),
135.1 (s, SiPh), 135.1 (s, SiPh), 138.1 (d, 1J PC ) 37 Hz, 2J PtC
)
1
2
17 Hz, PPh), 138.8 (dd, J PC ) 43 and 3 Hz, J PtC ) 14 Hz,
3
1
3
PPh), 141.1 (s, SiPh), 141.2 (s, SiPh), 153.3 (dd, J PC ) 5 and
Com p lex 3a . H NMR (CD2Cl2, 20 °C): δ -0.12 (s, J PtH
)
2
2
2
1 Hz, J PtC ) 35 Hz, Ph), 181.7 (dd, J PC ) 100 and 13 Hz,
7.5 Hz, J SnH ) 37.5 Hz, 9H, SnMe), 0.28 (s, 9H, SiMe), 1.14
1J PtC ) 712 Hz, PtCdCH). 31P{1H} NMR (CD2Cl2, 20 °C): δ
2
3
3
(d, J PH ) 8.4 Hz, J PtH ) 25.2 Hz, 3H, PMe), 1.35 (d, J PH
)
2
1
2
119
1
8.1 Hz, 2J PtH ) 22.8 Hz, 3H, PMe), 1.47 (d, 3J PH ) 8.1 Hz, 2J PtH
-13.8 (d, J PP ) 18 Hz, J PtP ) 2065 Hz,
J
) 1742 Hz,
SnP
2
2
2
117
3
2
J
J
) 1662 Hz), -16.7 (d, J PP ) 18 Hz, J PtP ) 1928 Hz,
SnP
) 22.8 Hz, 3H, PMe), 1.59 (d, J PH ) 8.1 Hz, J PtH ) 25.2 Hz,
3H, PMe), 7.0-7.6 (m, 14H, Ph and PtCdCH), 7.72 (m, 2H,
2
119
117
) 166 Hz, J
) 159 Hz). Anal. Calcd for C40H50P2-
SnP
SnP
Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ -4.2 (dd, J PC ) 10 and
3
SiSnPt: C, 51.40; H, 5.39. Found: C, 51.32; H, 5.33.
1
3
2 Hz, 2J PtC ) 77 Hz, 1J SnC ) 186 Hz, SnMe), 1.0 (s, SiMe), 13.6
Com p lex 3e. H NMR (CD2Cl2, 20 °C): δ -0.11 (s, J PtH
)
2
1
3
2
7.3 Hz, J SnH ) 37.2 Hz, 9H, SnMe), 0.40 (s, 3H, SiMe), 0.55
(s, 3H, SiMe), 1.14 (d, 2J PH ) 8.4 Hz, 3J PtH ) 23.4 Hz, 9H, PMe),
1.62 (d, 2J PH ) 8.1 Hz, 3J PtH ) 23.1 Hz, 9H, PMe), 6.9-7.8 (m,
10H, Ph), 7.45 (dd, 4J PH ) 19.8 and 4.2 Hz, 1H, PtCdCH). 13C-
(dd, J PC ) 26 Hz, J PC ) 2 Hz, J PtC ) 29 Hz, PMe), 14.5 (dd,
3
2
1
1J PC ) 29 Hz, J PC ) 3 Hz, J PtC ) 39 Hz, PMe), 18.7 (dd, J PC
) 30 Hz, 3J PC ) 5 Hz, 2J PtC ) 30 Hz, PMe), 19.2 (dd, 1J PC ) 31
3
2
5
Hz, J PC) 5 Hz, J PtC ) 40 Hz, PMe), 125.9 (s, J PtC ) 6 Hz,
{1H} NMR (CD2Cl2, 20 °C): δ -4.4 (dd, J PC ) 10 and 2 Hz,
3
3
4
Ph), 127.6 (s, Ph), 128.5 (d, J PC ) 9 Hz, PPh), 129.2 (d, J PC
2J PtC ) 77 Hz, SnMe), 0.1 (s, SiMe), 16.5 (dd, J PC ) 26 Hz,
1
3
2
) 2 Hz, J PtC ) 46 Hz, Ph), 129.7 (s, PPh), 130.8 (d, J PC ) 12
3J PC ) 3 Hz, J PtC ) 31 Hz, PMe), 20.6 (dd, J PC ) 30 Hz, J PH
2
1
3
2
3
Hz, PPh), 130.9 (d, J PC ) 11 Hz, PPh), 131.5 (t, J PC ) 7 Hz,
) 5 Hz, 2J PtC ) 33 Hz, PMe), 126.1 (s, 5J PtC ) 5 Hz, Ph), 126.9
2J PtC ) 43 Hz, PtCdCH), 138.1 (dd, J PC ) 36 Hz, J PC ) 2
1
3
3
2
Hz, 2J PtC ) 21 Hz, PPh), 139.0 (dd, J PC ) 42 Hz, 3J PC ) 3 Hz,
1
(t, J PC ) 6 Hz, J PtC ) 53 Hz, PtCdCH), 127.5 (s, Ph), 127.8
4
3
2J PtC ) 17 Hz, PPh), 153.6 (dd, J PC ) 5 and 2 Hz, J PtC ) 30
3
2
(s, SiPh), 128.4 (s, SiPh), 129.1 (d, J PC ) 2 Hz, J PtC ) 45 Hz,
3
2
1
Ph), 134.3 (s, SiPh), 142.9 (s, SiPh), 153.0 (dd, J PC ) 5 and 1
Hz, Ph), 175.9 (dd, J PC ) 97 and 14 Hz, J PtC ) 703 Hz, PtC
2
2
1
dCH). 31P{1H} NMR (CD2Cl2, 20 °C): δ -14.1 (d, J PP ) 17
2
Hz, J PtC ) 33 Hz, Ph), 179.1 (dd, J PC ) 101 and 13 Hz, J PtC
) 719 Hz, PtCdCH). 31P{1H} NMR (CD2Cl2, 20 °C): δ -24.5
1
2
2
119
117
Hz, J PtP ) 2081 Hz,
J
) 1784 Hz,
J
) 1704 Hz),
) 168 Hz,
SnP
SnP
2
1
2
2
2
1
2
119
1
117
119
119
(d, J PP ) 16 Hz, J PtP ) 2078 Hz, J
) 1813 Hz, J
-16.3 (d, J PP ) 17 Hz, J PtP ) 1927 Hz,
J
SnP
SnP
SnP
SnP
2
2
2
117
) 1731 Hz), -29.1 (d, J PP ) 18 Hz, J PtP ) 1878 Hz, J
J
) 161 Hz). Anal. Calcd for C30H46P2SiSnPt: C, 44.46;
SnP
2
117
) 172 Hz, J
) 164 Hz). Anal. Calcd for C25H44P2SiSnPt:
H, 5.72. Found: C, 44.43; H, 5.71.
SnP
1
3
C, 40.12; H, 5.93. Found: C, 39.71; H, 5.63.
Com p lex 3b. H NMR (CD2Cl2, 20 °C): δ -0.11 (s, J PtH
)
2
3
7.5 Hz, J SnH ) 37.5 Hz, 9H, SnMe), 0.51 (s, 3H, SiMe), 0.71
Com p lex 3f. 1H NMR (CD2Cl2, 20 °C): δ 0.00 (s, J PtH
)
(s, 3H, SiMe), 1.04 (d, 2J PH ) 8.7 Hz, 3J PtH ) 33.6 Hz, 3H, PMe),
6.3 Hz, J SnH ) 35.4 Hz, 9H, SnMe), 0.43 (s, 3H, SiMe), 0.67
2

4444 Organometallics, Vol. 22, No. 22, 2003
Sagawa et al.
3
3
1
3
(s, 3H, SiMe), 0.68 (dt, J PH ) 15.3 Hz, J HH ) 7.5 Hz, 9H,
Com p lex 3i. H NMR (CD2Cl2, 20 °C): δ -0.11 (s, J PtH
)
3
3
2
PCH2CH3), 1.13 (dt, J PH ) 15.3 Hz, J HH ) 7.5 Hz, 9H,
PCH2CH3), 1.57 (m, 6H, PCH2CH3), 1.97 (m, 6H, PCH2CH3),
7.5 Hz, J SnH ) 37.5 Hz, 9H, SnMe), 0.50 (s, 3H, SiMe), 0.70
(s, 3H, SiMe), 1.04 (d, 2J PH ) 8.7 Hz, 3J PtH ) 25.2 Hz, 3H, PMe),
2
3
4
1.14 (d, J PH ) 8.4 Hz, J PtH ) 22.8 Hz, 3H, PMe), 1.48 (d,
7.05-7.60 (m, 6H, Ph), 7.45 (dd, J PH ) 19.2 and 3.9 Hz, 1H,
2J PH ) 7.8 Hz, J PtH ) 22.8 Hz, 3H, PMe), 1.58 (d, J PH ) 8.1
3
2
PtCdCH), 7.64-7.67 (m, 4H, Ph). 13C{1H} NMR (CD2Cl2, 20
3
3
2
1
Hz, J PtH ) 25.2 Hz, 3H, PMe), 2.33 (s, 3H, Me), 7.0-7.7 (m,
°C): δ -2.9 (d, J PC ) 10 Hz, J PtC ) 74 Hz, J SnC ) 189 Hz,
SnMe), 0.5 (s, SiMe), 8.0 (d, J PC ) 2 Hz, J PtC ) 18 Hz,
PCH2CH3), 8.6 (s, J PtC ) 16 Hz, PCH2CH3), 16.7 (dd, J PC
24 Hz, 3J PC ) 2 Hz, 2J PtC ) 28 Hz, PCH2CH3), 19.4 (dd, 1J PC
27 Hz, 3J PC ) 4 Hz, 2J PtC ) 29 Hz, PCH2CH3), 125.8 (s, 5J PtC
6 Hz, Ph), 127.4 (s, Ph), 127.7 (s, SiPh), 128.3 (s, SiPh), 129.2
(d, 4J PC ) 2 Hz, 3J PtC ) 44 Hz, Ph), 130.0 (t, J PC ) 6 Hz, 2J PtC
20H, PtCdCH and Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ -4.2
(dd, 3J PC ) 10 and 1 Hz, 2J PtC ) 79 Hz, 1J SnC ) 190 Hz, SnMe),
2
3
3
1
)
)
)
1
3
2
0.24 (s, SiMe), 13.3 (dd, J PC ) 26 Hz, J PC ) 2 Hz, J PtC ) 26
1
3
2
Hz, PMe), 14.5 (dd, J PC ) 30 Hz, J PC ) 3 Hz, J PtC ) 39 Hz,
PMe), 18.7 (dd, 1J PC ) 15 Hz, 3J PC ) 6 Hz, 2J PtC ) 20 Hz, PMe),
1
3
2
3
19.2 (dd, J PC ) 16 Hz, J PC ) 4 Hz, J PtC ) 40 Hz, PMe), 21.1
3
2
(s, Me), 127.0 (t, J PC ) 7 Hz, J PtC ) 57 Hz, PtCdCH), 127.8
) 55 Hz, PtCdCH), 134.3 (s, SiPh), 143.1 (s, SiPh), 154.5 (dd,
(s, SiPh), 128.4 (s, SiPh), 128.4 (d, 3J PC ) 9 Hz, PPh), 128.4 (s,
3J PC ) 5 and 2 Hz, J PtC ) 33 Hz, Ph), 179.1 (dd, J PC ) 98
2
2
Ar), 128.5 (d, 3J PC ) 9 Hz, PPh), 129.2 (d, 4J PC ) 2 Hz, 3J PtC
)
and 13 Hz, J PtC ) 698 Hz, PtCdCH). 31P{1H} NMR (CD2Cl2,
1
4
4
2
1
2
51 Hz, Ar), 129.6 (d, J PC ) 2 Hz, PPh), 129.7 (d, J PC ) 2 Hz,
119
20 °C): δ 2.9 (d, J PP ) 16 Hz, J PtP ) 1932 Hz, J
) 164
SnP
2
3
2
2
1
PPh), 130.8 (d, J PC ) 12 Hz, J PtC ) 14 Hz, PPh), 130.9 (d,
117
117
Hz,
J
J
) 156 Hz), 0.1 (d, J PP ) 18 Hz, J PtP ) 2 Hz,
SnP ) 1770 Hz, J SnP ) 1692 Hz). Anal. Calcd for C31H56P2-
SiSnPt: C, 44.72; H, 6.78. Found: C, 44.74; H, 6.78.
Com p lex 3g. 1H NMR (CD2Cl2, 20 °C): δ -0.18 (s, 2J SnH
SnP
2J PC ) 11 Hz, J PtC ) 16 Hz, PPh), 134.3 (s, SiPh), 135.8 (s,
3
2
2
119
117
5J PtC ) 6 Hz, Ar), 138.1 (dd, J PC ) 36 Hz, J PC ) 2 Hz, J PtC
1
3
2
1
3
2
) 16 Hz, PPh), 138.9 (dd, J PC ) 42 Hz, J PC ) 4 Hz, J PtC
)
)
3
14 Hz, PPh), 143.0 (s, SiPh), 150.6 (dd, J PC ) 6 and 2 Hz,
38.4 Hz, 9H, SnMe), 0.65 (s, 3H, SiMe), 0.90 (s, 3H, SiMe),
2J PtC ) 38 Hz, Ar), 178.9 (dd, J PC ) 100 and 13 Hz, J PtC
)
2
1
2
3
1.45 (d, J PH ) 8.1 Hz, J PtH ) 22.8 Hz, 3H, PMe), 2.05 (d,
705 Hz, PtCdCH). 31P{1H} NMR (CD2Cl2, 20 °C): δ -13.9 (d,
2J PH ) 7.5 Hz, J PtH ) 24.6 Hz, 3H, PMe), 6.7-7.9 (m, 31H,
3
2J PP ) 17 Hz, J PtP ) 2079 Hz,
J
) 1776 Hz,
J
)
)
1
2
2
2
119
117
SnP
SnP
Ph and PtCdCH). 13C{1H} NMR (CD2Cl2, 20 °C): δ -3.6 (dd,
3J PC ) 10 and 2 Hz, 2J PtC ) 76 Hz, 1J SnC ) 194 Hz, SnMe), 0.1
2
1
119
1696 Hz), -16.6 (d, J PP ) 17 Hz, J PtP ) 1919 Hz, J
SnP
2
117
168 Hz,
J
) 160 Hz). Anal. Calcd for C36H50P2SiSnPt:
SnP
1
3
2
(s, SiMe), 13.4 (dd, J PC ) 28 Hz, J PC ) 2 Hz, J PtC ) 32 Hz,
PMe), 19.7 (dd, 1J PC ) 32 Hz, 3J PH ) 5 Hz, 2J PtC ) 36 Hz, PMe),
125.9 (s, 5J PtC ) 6 Hz, Ph), 127.2 (s, Ph), 127.9 (s, SiPh), 128.4
C, 48.77; H, 5.68. Found: C, 48.42; H, 5.71.
1
3
Com p lex 3j. H NMR (CD2Cl2, 20 °C): δ -0.12 (s, J PtH
)
2
7.2 Hz, J SnH ) 35.7 Hz, 9H, SnMe), 0.51 (s, 3H, SiMe), 0.71
4
(s, SiPh), 128.4 (m, PPh), 129.0 (d, J PC ) 2 Hz, Ph), 129.3 (d,
(s, 3H, SiMe), 1.04 (d, 2J PH ) 8.7 Hz, 3J PtH ) 24.6 Hz, 3H, PMe),
4J PC ) 2 Hz, PPh), 129.6 (d, J PC ) 2 Hz, PPh), 130.2 (d, J PC
4
4
2
3
1.14 (d, J PH ) 8.1 Hz, J PtH ) 23.4 Hz, 3H, PMe), 1.50 (d,
4
2
) 2 Hz, PPh), 130.2 (d, J PC ) 2 Hz, PPh), 132.2 (d, J PC ) 10
2J PH ) 8.1 Hz, J PtH ) 23.4 Hz, 3H, PMe), 1.59 (d, J PH ) 8.1
Hz, 3J PtH ) 27.6 Hz, 3H, PMe), 7.0-7.9 (m, 20H, PtCdCH and
Ph), 9.95 (s, 1H, CHO). 13C{1H} NMR (CD2Cl2, 20 °C): δ -4.2
(dd, 3J PC ) 10 and 2 Hz, 2J PtC ) 76 Hz, 1J SnC ) 196 Hz, SnMe),
3
2
Hz, 3J PtC ) 14 Hz, PPh), 132.4 (d, 2J PC ) 11 Hz, 3J PtC ) 17 Hz,
2
3
PPh), 133.2 (d, J PC ) 12 Hz, J PtC ) 15 Hz, PPh), 133.6 (d,
2J PC ) 12 Hz, J PtC ) 20 Hz, PPh), 134.3 (s, SiPh), 136.9 (dd,
3
1J PC ) 45 Hz, 3J PC ) 3 Hz, 2J PtC ) 26 Hz, PPh), 137.9 (dd, 1J PC
1
3
2
0.0 (s, SiMe), 13.4 (dd, J PC ) 26 Hz, J PC ) 2 Hz, J PtC ) 27
3
2
) 42 Hz, J PC ) 5 Hz, J PtC ) 26 Hz, PPh), 142.8 (s, SiPh),
1
3
2
Hz, PMe), 14.7 (dd, J PC ) 30 Hz, J PC ) 3 Hz, J PtC ) 38 Hz,
3
2
153.0 (dd, J PC ) 5 and 2 Hz, J PtC ) 31 Hz, Ph), 177.5 (dd,
1
3
1
PMe), 18.7 (dd, J PC ) 9 Hz, J PC ) 5 Hz, PMe), 19.1 (dd, J PC
2J PC ) 98 and 13 Hz, J PtC ) 719 Hz, PtCdCH). The â-vinylic
1
3
3
) 10 Hz, J PC ) 5 Hz, PMe), 127.9 (s, SiPh), 128.5 (d, J PC
)
carbon signal was not assigned. 31P{1H} NMR (CD2Cl2, 20
9 Hz, PPh), 128.6 (m, 3J PC ) 9 Hz, PPh), 128.7 (s, SiPh), 129.3
2
1
2
119
°C): δ 1.5 (d, J PP ) 16 Hz, J PtP ) 2063 Hz,
J
) 1723
SnP
(s, Ar), 129.7 (d, 4J PC ) 2 Hz, 3J PtC ) 46 Hz, Ar), 129.7 (d, 4J PC
2
2
1
117
Hz,
Hz,
J
J
) 1677 Hz), -1.1 (d, J PP ) 16 Hz, J PtP ) 1965
SnP
4
2
) 2 Hz, PPh), 129.9 (d, J PC ) 2 Hz, PPh), 130.7 (d, J PC ) 12
Hz, 3J PtC ) 14 Hz, PPh), 130.8 (d, 2J PC ) 12 Hz, 3J PtC ) 16 Hz,
PPh), 133.1 (t, 3J PC ) 6 Hz, 2J PtC ) 52 Hz, PtCdCH), 134.3 (s,
SiPh), 134.4 (s, 5J PtC ) 6 Hz, Ar), 137.6 (dd, 1J PC ) 37 Hz, 3J PC
2
2
119
117
) 166 Hz,
J
) 160 Hz). Anal. Calcd for
SnP
SnP
C
45H52P2SiSnPt: C, 54.23; H, 5.26. Found: C, 53.98; H, 5.30.
1
3
Com p lex 3h . H NMR (CD2Cl2, 20 °C): δ -0.12 (s, J PtH
)
2
2
1
3
7.2 Hz, J SnH ) 37.2 Hz, 9H, SnMe), 0.49 (s, 3H, SiMe), 0.69
) 2 Hz, J PtC ) 16 Hz, PPh), 138.9 (dd, J PC ) 43 Hz, J PC
)
(s, 3H, SiMe), 1.07 (d, 2J PH ) 8.4 Hz, 3J PtH ) 25.8 Hz, 3H, PMe),
2
3
3 Hz, J PtC ) 14 Hz, PPh), 142.2 (s, SiPh), 159.7 (dd, J PC ) 6
and 2 Hz, 2J PtC ) 36 Hz, Ar), 177.6 (dd, 2J PC ) 100 and 13 Hz,
1J PtC ) 716 Hz, PtCdCH), 192.3 (s, CHO). 31P{1H} NMR (CD2-
2
3
1.14 (d, J PH ) 8.1 Hz, J PtH ) 23.4 Hz, 3H, PMe), 1.47 (d,
2J PH ) 7.8 Hz, J PtH ) 22.8 Hz, 3H, PMe), 1.57 (d, J PH ) 8.1
3
2
3
2
1
2
119
Hz, J PtH ) 24.9 Hz, 3H, PMe), 3.64 (s, 2H, NH2), 6.6-7.7 (m,
Cl2, 20 °C): δ -13.9 (d, J PP ) 18 Hz, J PtP ) 2041 Hz, J
SnP
20H, PtCdCH and Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ -4.2
2
2
1
117
) 1747 Hz, J
) 1671 Hz), -16.7 (d, J PP ) 18 Hz, J PtP
SnP
(dd, 3J PC ) 10 and 2 Hz, 2J PtC ) 78 Hz, 1J SnC ) 189 Hz, SnMe),
2
2
119
117
) 1968 Hz, J
) 166 Hz, J
) 158 Hz). Anal. Calcd
SnP
SnP
1
3
2
0.39 (s, SiMe), 13.2 (dd, J PC ) 26 Hz, J PC ) 2 Hz, J PtC ) 28
for C36H48P2OSiSnPt: C, 48.01; H, 5.37. Found: C, 48.05; H,
5.35.
1
3
2
Hz, PMe), 14.5 (dd, J PC ) 30 Hz, J PC ) 3 Hz, J PtC ) 40 Hz,
PMe), 18.7 (dd, 1J PC ) 5 Hz, 3J PC ) 3 Hz, 2J PtC ) 31 Hz, PMe),
Kin etic Stu d y. Complex 1b (11.5 mg, 14.9 µmol) and PhCt
CH (9.2-35.5 mg) were placed in an NMR sample tube
equipped with a rubber septum cap and dissolved at -50 °C
in CD2Cl2 containing free PMe2Ph (2.5-30 mM) to obtain a
total volume of the solution of 0.6 mL. The sample tube was
placed in an NMR sample probe controlled at -5.0 ( 0.1 °C
and examined at intervals by 1H NMR spectroscopy. The
amounts of 1b, 2b, and 3b at time t were determined by peak
integration of the SnMe3 signals at δ -0.02 (1b), 0.24 (2b),
and -0.17 (3b).
Cr ossover Exp er im en ts for th e Con ver sion of 2b to
3b. Complex 1b (11.5 mg, 14.9 µmol) was dissolved in CD2Cl2
(0.6 mL) containing free PMe2Ph (2.5 mM) at -50 °C. Phenyl-
acetylene (1.6 µL, 14.6 µmol) was added, and the sample
solution was allowed to stand at -5 °C for 1 h. The 31P{1H}
NMR analysis revealed the formation of 2b and 3b in a 30/70
ratio. Then, p-MeC6H4CtCH (5.6 µL, 44.8 µmol) was added,
1
2
19.1 (t, J PC ) 9 Hz, J PtC ) 39 Hz, PMe), 114.2 (s, Ar), 123.8
(t, 3J PC ) 6 Hz, 2J PtC ) 57 Hz, PtCdCH), 127.8 (s, SiPh), 128.4
3
3
(s, SiPh), 128.4 (d, J PC ) 9 Hz, PPh), 128.5 (d, J PC ) 9 Hz,
PPh), 129.6 (d, 4J PC ) 2 Hz, PPh), 129.7 (d, 4J PC ) 2 Hz, PPh),
4
3
2
130.3 (d, J PC ) 2 Hz, J PtC ) 48 Hz, Ar), 130.7 (d, J PC ) 12
Hz, 3J PtC ) 14 Hz, PPh), 130.9 (d, 2J PC ) 12 Hz, 3J PtC ) 15 Hz,
1
3
PPh), 134.3 (s, SiPh), 138.3 (dd, J PC ) 36 Hz, J PC ) 2 Hz,
2J PtC ) 17 Hz, PPh), 139.1 (dd, J PC ) 42 Hz, J PC ) 4 Hz,
1
3
2J PtC ) 15 Hz, PPh), 143.3 (s, SiPh), 144.0 (dd, J PC ) 6 and 2
3
2
5
Hz, J PtC ) 38 Hz, Ar), 145.5 (s, J PtC ) 6 Hz, Ar), 178.2 (dd,
2J PC ) 99 and 13 Hz, 1J PtC ) 699 Hz, PtCdCH). 31P{1H} NMR
2
1
(CD2Cl2, 20 °C): δ -13.5 (d, J PP ) 18 Hz, J PtP ) 2091 Hz,
2
2
119
117
J
) 1782 Hz, J
) 1703 Hz), -16.3 (d, 2J PP ) 17 Hz,
2
SnP
SnP
1J PtP ) 1891 Hz,
Calcd for 35H49NP2SiSnPt: C, 47.36; H, 5.56; N, 1.58.
Found: C, 47.33; H, 5.51; N, 1.62.
J
) 168 Hz,
J
) 160 Hz). Anal.
2
119
117
SnP
SnP
C

Alkyne Insertion into cis-Silyl(stannyl) Pt(II)
Organometallics, Vol. 22, No. 22, 2003 4445
Ta ble 5. Cr ysta l Da ta a n d Deta ils of th e Str u ctu r e
Deter m in a tion for 1d a n d 2k
data (h00: h * 2n; 0k0: k * 2n; 00l: l * 2n), the space group
was uniquely determined to be P212121 (#19). The data were
collected at 22 ( 1 °C to a maximum 2θ value of 55.0°. A total
of 80 images, corresponding to 222.5° oscillation angles, were
collected with two different goniometer settings. Exposure time
was 1.70 min per degree. The camera radius was 127.40 mm.
Readout was performed in the 0.150 mm pixel mode. Of the
38 954 reflections collected, 5282 were unique (Rint ) 0.078);
equivalent reflections were merged. The data were corrected
for Lorentz and polarization effects and absorption (NUMABS).
Com p lex 2k . An orange crystal having approximate di-
mensions of 0.2 × 0.2 × 0.2 mm, which was grown by slow
diffusion of a CH2Cl2 solution in pentane at -25 °C, was
mounted on a glass fiber. All measurements were performed
on a Rigaku AFC7R four-circle diffractometer with graphite-
monochromated Mo KR radiation (λ ) 0.71069 Å). Unit cell
dimensions were obtained from a least-squares treatment of
the setting angles of 25 automatically centered reflections with
θ > 25°. The unit cell dimensions, a statistical analysis of
intensity distribution, and the successful solution and refine-
ment of the structure indicated the space group P1h (#2). The
intensity data were collected at -75 ( 1 °C to a maximum 2θ
value of 55.0° using ω-2θ scan technique at a scan rate of 16
deg/min-1 in omega. Of the 9066 reflections collected, 3025
were unique (Rint ) 0.025). The data were corrected for Lorentz
and polarization effects, decay (5.4%, based on three standard
reflections monitored at every 150 reflection measurements),
and absorption (empirical, based on azimuthal scans of three
reflections).
1d
2k
formula
fw
C
41H54OP2SiSnPt
C33H48O4P2SiSnPt
912.55
966.69
cryst size, mm
cryst syst
no. of reflns used for
unit cell determination
(2θ range, deg)
a (Å)
0.23 × 0.2 × 0.2
orthorhombic
60511 (4.6-55.0)
0.2 × 0.2 × 0.2
triclinic
25 (29.9-30.0)
17.8553(4)
19.7769(6)
11.8019(3)
11.845(3)
16.684(5)
10.484(3)
100.03(3)
111.73(2)
75.72(2)
1857(1)
P1h (#2)
2
1.632
45.70
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
4167.5(2)
P212121 (#19)
4
1.541
40.73
Rigaku
RAXIS-RAPID
(imaging plate)
22
55.0
38954
space group
Z
dcalcd (g cm-3
)
µ(Mo KR) (cm-1
)
diffractometer
Rigaku AFC7R
(ω-2θ scan)
temp, °C
2θ max (deg)
no. of reflns collected
no. of unique reflns
transmn factors
-75
55.0
9066
5282 (Rint ) 0.078) 3025 (Rint ) 0.025)
0.3277-0.5056
4562 (I g 3.0σ(I))
401
R1 ) 0.028
R ) 0.046
Rw ) 0.061
GOF ) 1.01
0.000
0.3635-0.9991
8381 (I g 3.0σ(I))
380
R1 ) 0.052
R ) 0.088
Rw ) 0.197
GOF ) 1.55
0.003
no. of obsd reflns
no. of variables
R indices (I g 3σ(I))a
(b) Str u ctu r e Solu tion a n d Refin em en t. All calculations
were performed with the TEXSAN Crystal Structure Analysis
Package provided by Rigaku Corp. The structure was solved
by heavy atom Patterson methods (PATTY) and expanded
using Fourier techniques (DIRDIF94). All non-hydrogen at-
oms, except for the carbon and oxygen atoms of the crystal
solvent in 1d ‚THF, were refined anisotropically. In the final
cycles of refinement, hydrogen atoms were located at idealized
positions (d(C-H) ) 0.95 Å) with isotropic temperature factors
(Biso ) 1.20Bbonded atom) and were included in calculation without
refinement of their parameters. The function minimized in
max. ∆/σ in final
cycle
max. and min. peak
0.63, -1.21
1.98, -4.11
(e Å-3
)
Function minimized ) ∑w(Fo - Fc2)2; w ) (1/[σ2(Fo2)]. R1
)
a
2
∑||Fo| - |Fc||/∑|Fo|. R ) ∑(Fo - Fc2)/∑(Fo2). Rw ) [∑w(Fo - Fc2)2/
∑w(Fo2)2]1/2. GOF ) [∑w(|Fo| - |Fc|)2/(No - Nv)]1/2, where No and
Nv stand for the number of observations and variables, respec-
tively.
2
2
least-squares was ∑w(Fo2 - Fc )2 (w ) 1/[σ2(Fo2)]). Crystal data
2
and the sample was warmed at 35 °C for 3 h. The 31P{1H}
and details of data collection and refinement are summarized
in Table 5. Additional information is available as Supporting
Information.
NMR spectrum measured at 20 °C showed complete conversion
1
of 2b to 3b. In the H NMR spectrum, no trace of the methyl
proton signal of 3i at δ 2.33 was detected, while the signal
due to the methyl group of p-MeC6H4CtCH at δ 2.48 remained
unchanged. A similar experiment was carried out using PhCt
CH (3 equiv) and a 28/78 mixture of 2i and 3i. In this case, no
trace of the methyl proton signal of free p-MeC6H4CtCH at δ
2.48 was detected.
Ack n ow led gm en t. This work was supported by a
Grant-in-Aid for Scientific Research from the Ministry
of Education, Culture, Sports, Science and Technology,
J apan.
X-r a y Str u ctu r a l An a lysis. (a ) Da ta Collection . 1d ‚
THF : A yellow block crystal having approximate dimensions
of 0.23 × 0.2 × 0.2 mm, which was grown from a mixed solvent
of THF and Et2O at -25 °C, was mounted on a glass fiber. All
measurements were made on a Rigaku RAXIS-RAPID imaging
plate diffractometer with graphite-monochromated Mo KR
radiation (λ ) 0.71069 Å). Indexing was performed from 1
oscillation which was exposed for 2.5 min. Based on the unit
cell dimensions and systematic absences in the diffractometer
Su p p or tin g In for m a tion Ava ila ble: Details of the struc-
ture determination of 1d and 2k , including figures giving the
atomic numbering schemes and tables of atomic coordinates,
thermal parameters, and full bond distances and angles. This
material is available free of charge via the Internet at
http://pubs.acs.org.
OM030553T