Preparation and C-Si reductive elimination behavior of cis-alkynyl(silyl)platinum(II) complexes

Article abstract of DOI:10.1021/om0302701

A series of cis-alkynyl(silyl)platinum(II) complexes, cis-Pt(C≡CAr)(SiAr′₃)(PMe₂Ph)₂ (2: Ar = Ph, 4-MeOC₆H₄, 4-MeC₆H₄, 4-ClC₆H₄, 4-BrC₆H₄, 4-NCC ₆H₄; Ar′ = Ph, 4-MeOC₆H₄, 4-MeC₆H₄, 4-CF₃C₆H₄), have been prepared, and their thermolysis reactions in solution have been examined. Complexes 2 smoothly undergo C-Si reductive elimination in benzene-d₆ at around 35 °C to give the corresponding platinum(O) complexes coordinated with silylacetylenes, Pt(ArC≡CSiAr′ ₃)(PMe₂Ph)₂ (3). Kinetic examinations suggest a concerted reaction process that is operative directly from the four-coordinate complexes. The more electron-donating substituents on the Ar and Ar′ groups provide higher reductive elimination rates.

Full text of DOI:10.1021/om0302701

Organometallics 2003, 22, 3593-3599
3593
P r ep a r a tion a n d C-Si Red u ctive Elim in a tion Beh a vior
of cis-Alk yn yl(silyl)p la tin u m (II) Com p lexes
Fumiyuki Ozawa* and Takuya Mori
Department of Applied Chemistry, Graduate School of Engineering, Osaka City University,
Sumiyoshi-ku, Osaka 558-8585, J apan
Received April 14, 2003
A series of cis-alkynyl(silyl)platinum(II) complexes, cis-Pt(CtCAr)(SiAr′3)(PMe2Ph)2
(2: Ar ) Ph, 4-MeOC6H4, 4-MeC6H4, 4-ClC6H4, 4-BrC6H4, 4-NCC6H4; Ar′ ) Ph, 4-MeOC6H4,
4-MeC6H4, 4-CF3C6H4), have been prepared, and their thermolysis reactions in solution have
been examined. Complexes 2 smoothly undergo C-Si reductive elimination in benzene-d6
at around 35 °C to give the corresponding platinum(0) complexes coordinated with
silylacetylenes, Pt(ArCtCSiAr′3)(PMe2Ph)2 (3). Kinetic examinations suggest a concerted
reaction process that is operative directly from the four-coordinate complexes. The more
electron-donating substituents on the Ar and Ar′ groups provide higher reductive elimination
rates.
In tr od u ction
processes are operative in the presence of diphenyl-
acetylene. In the first process, RSiPh3 is formed from a
PtR(SiPh3)(PhCtCPh)L intermediate, generated by
ligand displacement of cis-PtR(SiR3)L2 with diphenyl-
acetylene. On the other hand, in the second process, the
alkyl-silyl complexes are initially converted into cis-
PtPh(SiRPh2)L2 by intramolecular exchange of the Pt-R
group with the Si-Ph group, and the subsequent C-Si
reductive elimination affords RSiPh3 via the intermedi-
ate PtPh(SiRPh2)(PhCtCPh)L.
In this paper we examine the mechanism of C-Si
reductive elimination from cis-Pt(CtCAr)(SiAr′3)(PMe2-
Ph)2 complexes. It has been documented that the
mechanism of C-C reductive elimination from d8 metal
complexes is significantly affected by the nature of
σ-carbyl ligands, especially by hybridization of the
carbon atom bonded to metal.5 For example, cis-dialkyl-
palladium(II) complexes (cis-PdR2L2: R ) Me, Et)
undergo C-C reductive elimination with prior dissocia-
tion of L,6 whereas aryl-alkyl and alkenyl-alkyl ana-
logues (cis-PdRR′L2: R′ ) Ph, PhCHdCH, etc.) provide
the reductive elimination products (R-R′) without dis-
sociation of L.7 Similarly, we found in this study that
the alkynyl(silyl)platinum(II) complexes undergo a C-Si
reductive elimination process, clearly different from that
previously observed for alkyl-silyl analogues. Thus, the
reaction proceeds directly from the four-coordinate
species without dissociation of phosphine.
Reductive elimination leading to C-Si bond formation
has often been assumed as a product-forming step in
transition-metal-catalyzed silylation of organic com-
pounds.1 However, mechanistic information about this
elementary process has been limited.2-4 In previous
studies we prepared cis-alkyl(silyl)platinum(II) com-
plexes (cis-PtR(SiPh3)L2: R ) Me, Et, Pr, Bu; L ) PMe2-
Ph, PMePh2) and examined their thermolysis reactions
in solution by kinetic experiments.4 Although the com-
plexes are fairly stable in neat solvents, they readily
undergo C-Si reductive elimination to give RSiPh3 in
the presence of alkynes or alkenes. Two types of
(1) (a) Suginome, M.; Ito, Y. Chem. Rev. 2000, 100, 3221. (b)
Beletskaya, I.; Moberg, C. Chem. Rev. 1999, 99, 3435. (c) Corey, J . Y.;
Braddock-Wilking, J . Chem. Rev. 1999, 99, 175. (d) Braunstein, P.;
Knorr, M. J . Organomet. Chem. 1995, 500, 21. (e) Hiyama, T.;
Kusumoto, T. In Comprehensive Organic Synthesis; Trost, B. M.,
Fleming, I., Eds.; Pergamon Press: Oxford, U.K., 1991; Vol. 8, p 763.
(f) Ojima, I. In The Chemistry of Organic Silicon Compounds; Patai,
S., Rappoport, Z., Eds.; Wiley: Chichester, U.K., 1989; p 1479. (g)
Tilley, T. D. In The Chemistry of Organic Silicon Compounds; Patai,
S., Rappoport, Z., Eds.; Wiley: Chichester, U.K., 1989; p 1415.
(2) (a) Roy, A. K.; Taylor, R. B. J . Am. Chem. Soc. 2002, 124, 9510.
(b) Maruyama, Y.; Yamamura, K.; Sagawa, T.; Katayama, H.; Ozawa,
F. Organometallics 2000, 19, 1308. (c) van der Boom, M. E.; Ott, J .;
Milstein, D. Organometallics 1998, 17, 4263. (d) Tanaka, Y.; Ya-
mashita, H.; Shimada, S.; Tanaka, M. Organometallics 1997, 16, 3246.
(e) Akita, M.; Hua, R.; Oku, T.; Tanaka, M.; Moro-oka, Y. Organo-
metallics 1996, 15, 4162. (f) Okazaki, M.; Tobita, H.; Ogino, H.
Organometallics 1996, 15, 2790. (g) Mitchell, G. P.; Tilley, T. D.
Organometallics 1996, 15, 3477. (h) Aizenberg, M.; Milstein, D. J . Am.
Chem. Soc. 1995, 117, 6456. (i) Schubert, U. Angew. Chem., Int. Ed.
Engl. 1994, 33, 419. (j) Lin, W.; Wilson, S. R.; Girolami, G. S.
Organometallics 1994, 13, 2309. (k) Schubert, U.; Mu¨ller, C. J .
Organomet. Chem. 1989, 373, 165. (l) Brinkman, K. C.; Blakeney, A.
J .; Krone-Schmidt, W.; Gladysz, J . A. Organometallics 1984, 3, 1325.
(3) (a) Beste, A.; Frenking, G. Z. Anorg. Allg. Chem. 2000, 626, 381.
(b) Biswas, B.; Sugimoto, M.; Sakaki, S. Organometallics 1999, 18,
4015. (c) Sakaki, S.; Mizoe, N.; Sugimoto, M. Organometallics 1998,
17, 2510. (d) Sakaki, S.; Mizoe, N.; Musashi, Y.; Sugimoto, M. J . Phys.
Chem. A 1998, 102, 8027.
Resu lts
P r ep a r a tion of cis-P t(CtCAr )(SiAr ′3)(P Me2P h )2
(2). Scheme 1 summarizes synthetic routes to 2. Unlike
(5) Ozawa, F. In Current Methods in Inorganic Chemistry, 3.
Fundamentals of Molecular Catalysis; Kurosawa, H., Yamamoto, A.,
Eds.; Elsevier Science: Amsterdam, 2003; p 479.
(6) (a) Ozawa, F.; Ito, T.; Nakamura, Y.; Yamamoto, A. Bull. Chem.
Soc. J pn. 1981, 54, 1868. (b) Gillie, A.; Stille, J . K. J . Am. Chem. Soc.
1980, 102, 4933.
(7) (a) Brown, J . M.; Cooley, N. A. Organometallics 1990, 9, 353.
(b) Ozawa, F.; Kurihara, K.; Fujimori, M.; Hidaka, T.; Toyoshima, T.;
Yamamoto, A. Organometallics 1989, 8, 180. (c) Loar, M. K.; Stille, J .
K. J . Am. Chem. Soc. 1981, 103, 4174.
(4) (a) Ozawa, F. J . Organomet. Chem. 2000, 611, 332. (b) Hasebe,
K.; Kamite, J .; Mori, T.; Katayama, H.; Ozawa, F. Organometallics
2000, 19, 2022. (c) Ozawa, F.; Kitaguchi, M.; Katayama, H. Chem. Lett.
1999, 1289. (d) Ozawa, F.; Hikida, T.; Hasebe, K.; Mori, T. Organo-
metallics 1998, 17, 1018. (e) Ozawa, F.; Hikida, T.; Hayashi, T. J . Am.
Chem. Soc. 1994, 116, 2844.
10.1021/om0302701 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 07/25/2003

3594 Organometallics, Vol. 22, No. 17, 2003
Ta ble 1. Selected NMR Da ta for cis-P t(CtCAr )(SiAr ′3)(P Me2P h )2 (2a -i)a
Ozawa and Mori
complex
Ar′
13C{1H} NMR: δ (ppm) [J PC (Hz)]
31P{1H} NMR: δ (ppm) [1J PtP (Hz)] {2J SiP (Hz)}b
Ar
ArCtCPt (Câ)
ArCtCPt (CR)
P trans to Si
P trans to C
Ph
Ph
Ph
Ph
Ph
Ph
Ph
2a
2b
2c
2d
2e
2f
2g
2h
2i
115.9 (dd) [32, 2]
115.5 (dd) [31, 2]
115.9 (dd) [29, 2]
114.7 (dd) [30, 3]
114.8 (dd) [31, 5]
115.3 (dd) [30, 4]
115.5 (dd) [31, 3]
115.2 (dd) [33, 3]
117.2 (dd) [30, 3]
113.7 (dd) [126, 21]
110.9 (dd) [127, 20]
112.4 (dd) [127, 19]
115.6 (dd) [126, 18]
116.0 (dd) [128, 18]
122.7 (dd) [125, 19]
113.9 (dd) [127, 20]
113.8 (dd) [126, 21]
111.7 (dd) [126, 20]
-6.1 (d) [1137] {177}
-6.3 (d) [1137] {179}
-6.0 (d) [1134] {177}
-6.1 (d) [1139] {177}
-6.1 (d) [1139] {177}
-6.1 (d) [1146] {174}
-5.6 (d) [1080] {176}
-5.8 (d) [1095] {176}
-6.2 (d) [1281] {208}
-14.2 (d) [2667] {0}
-14.3 (d) [2663] {0}
-14.3 (d) [2665] {0}
-14.2 (d) [2664] {0}
-14.2 (d) [2667] {0}
-14.2 (d) [2664] {0}
-13.5 (d) [2667] {0}
-14.2 (d) [2661] {0}
-14.7 (d) [2624] {0}
4-MeOC6H4
4-MeC6H4
4-ClC6H4
4-BrC6H4
4-NCC6H4
Ph
4-MeOC6H4
4-MeC6H4
4-CF3C6H4
Ph
Ph
a
b
NMR spectra were measured in CD2Cl2 at -20 °C (2a -f) or -30 °C (2g-i). Doublet signals are due to the P-P coupling (2J PP ) 23
Hz).
Sch em e 1a
F igu r e 1. Dependence of the chemical shifts of R-acety-
lenic carbons in 2a -h upon the σp values of para substit-
a
L ) PMe2Ph.
uents on the Ar groups. The σp values were taken from ref
9.
the cis-alkyl-silyl analogues,4 direct synthesis of 2 from
trans-PtCl(SiAr′3)L2 by treatment with alkynyllithium
instead gave a mixture of trans and cis isomers of the
alkynyl-silyl complex (1 and 2, respectively). On the
other hand, 2 was successfully prepared by trans to cis
isomerization of 1. This reaction proceeds smoothly in
CH2Cl2 under a CO atmosphere at low temperature
(-20 °C) without concomitant CO insertion and reduc-
tive elimination. The parent 1 can be prepared by either
the reaction of trans-PtCl(SiAr′3)L2 with ArCtCMgCl
in THF (method A) or the treatment of trans-PtMe-
(SiAr′3)L2 with ArCtCH in benzene (method B).8 While
the latter method requires a long reaction time (ca. 5
days), it forms methane as the only byproduct, making
the workup procedure very simple.
The cis-alkynyl-silyl complexes bearing a variety of
Ar and Ar′ groups (2a -i) were thus prepared and
characterized by NMR spectroscopy and elemental
analysis. Selected 13C{1H} and 31P{1H} NMR data are
listed in Table 1. The â-carbon signal of the alkynyl
ligand appears as a doublet of doublets at around δ 115,
irrespective of the sorts of Ar and Ar′ groups. On the
other hand, the R-carbon signal is clearly shifted to a
lower magnetic field as the more electron-withdrawing
group is substituted at the para position of the Ar group;
the chemical shifts for 2a -h exhibit a good Hammett
correlation (r ) 0.985) with the σp values of substitu-
ents: δC(R) ) [12.1(9)]σp + 113.8(2) (Figure 1).
1
A clear tendency is also observed for the J PtP values
of the phosphorus trans to silyl ligands. Thus, the
coupling constant increases as the para substituent of
the Ar′ group on silicon becomes more electron-with-
drawing. The substituent effect is rationalized by the
1
following equation for all complexes (r ) 0.996): J PtP
) [85(3)]∑(1-3)σp + 1140(2) (Figure 2).
Red u ctive Elim in a tion fr om 2. Complexes 2a -h
cleanly underwent C-Si reductive elimination in ben-
zene-d6 at 30-40 °C to give Pt(0) complexes coordinated
with silylalkynes (3a -h ) (Scheme 2), while 2i, having
the most electron-deficient silyl group, was exceptionally
stable under the reaction conditions. 31P{1H} NMR
spectra of the reaction solutions after thermolysis
2
exhibited AB quartet signals with J PP values of 37-38
1
Hz and J PtP values of 3319-3570 Hz, the values of
which are consistent with the formation of the Pt(0)
alkyne complexes. Complexes 3a -h were further char-
acterized by 1H and 13C{1H} NMR spectroscopy (see
Experimental Section).
1
The reductive elimination was followed by H NMR
spectroscopy using MeSiPh3 as an internal standard.
The rate constants (kobsd) are listed in Table 2. All runs
obeyed good first-order kinetics for at least 2 half-lives.
Unlike the reactions of cis-alkyl-silyl analogues, the
(8) Complexes 1a -f were isolated by recrystallization and charac-
terized by 1H, 13C{1H}, and 31P{1H} NMR spectroscopy and elemental
analysis. On the other hand, 1g-i were employed as crude products
in the synthesis of cis isomers, while their formation was confirmed
by 31P{1H} NMR spectroscopy.

cis-Alkynyl(silyl)platinum(II) Complexes
Organometallics, Vol. 22, No. 17, 2003 3595
1
F igu r e 2. Dependence of the J PtP values for the phos-
F igu r e 3. Hammett plot for the rate constants of runs 2,
6, and 7 in Table 2 against the σp values of para substit-
uents on Ar groups. The σp values were taken from ref 9.
phorus trans to silyl ligands in 2a -i upon the sum of the
σp values of para substituents on the SiAr′3 groups. The σp
values were taken from ref 9.
Discu ssion
Sch em e 2a
The kinetic observations described above are fully
consistent with the reductive elimination process given
in Scheme 2, which is operative directly from the four-
coordinated species 2 in a concerted manner. A similar
type process has been proposed for C-C reductive
elimination from cis-Pt(CtCBut)(CMedCH2)(PPh3)2.10
A clear substituent effect has been observed. Thus, the
reductive elimination rate is effectively reduced by
electron-withdrawing substituents on the Ar and Ar′
groups.11
Two types of mechanisms have been documented for
C-C reductive elimination from d8 metal complexes.5
One involves simultaneous elimination of two σ-carbyl
ligands with concomitant formation of a C-C bond via
a three-center transition state. This mechanism has
been assumed for dialkyl complexes bearing two sp3-
hybridized carbon ligands.12 On the other hand, the
other one is the so-called “migratory reductive elimina-
tion”, which has been proposed for diorgano complexes
having sp2- or sp-hybridized carbon ligands (e.g., aryl,
alkenyl, CN).7b,13,14 Thus, the C-C bond is formed by
nucleophilic attack of one of the carbyl ligands upon the
other carbyl ligand in a migration manner. Accordingly,
the reductive elimination by this mechanism exhibits
opposite substituent effects with respect to the two
a
L ) PMe2Ph.
Ta ble 2. F ir st-Or d er Ra te Con sta n ts for Red u ctive
Elim in a tion fr om cis-P t(CtCAr )(SiAr ′3)(P Me2P h )2
(2a -i)a
run
Ar
Ar′
compd temp 103kobsd (s-1
)
1
2
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
2a
2a
2a
2a
2a
2b
2c
2d
2e
2f
30
35
35
40
45
35
35
35
35
35
35
35
40
0.128(8)
0.283(2)
0.285(7)
0.533(3)
1.06(10)
0.575(4)
0.422(3)
0.153(1)
0.147(1)
0.078(2)
0.55(2)
3b
4
5
6
7
8
4-MeOC6H4 Ph
4-MeC6H4
4-ClC6H4
4-BrC6H4
4-NCC6H4
Ph
Ph
Ph
Ph
Ph
9
10
11
12
13
4-MeOC6H4
4-MeC6H4
4-CF3C6H4
2g
2h
2i
Ph
Ph
0.468(3)
very slow
a
All runs were examined in benzene-d6 by 1H NMR spectros-
b
copy: [2]0 ) 0.03 M. PMe2Ph (0.03 M) was added.
(9) Inamoto, N. Hammett Soku (The Hammett Rule); Maruzen:
Tokyo, 1983.
reaction of 2a readily proceeds in the absence of alkyne
promoters, and the reaction rate is not affected by
addition of free PMe2Ph to the system (1 equiv) (runs 2
and 3). The activation parameters estimated for the
temperature range of 30-45 °C (runs 1-5) are as
follows: ∆Hq ) 26.4(7) kcal mol-1, ∆Sq ) 10(2) eu,
(10) Stang, P. J .; Kowalski, M. H. J . Am. Chem. Soc. 1989, 111, 3356.
(11) Although scattering reports have appeared for reductive elimi-
nation from alkynyl complexes of d8 metals, no systematic information
has been reported for the substituent effects of alkynyl ligands: (a)
Mann, G.; Baranano, D.; Hartwig, J . F.; Rheingold, A. L.; Guzei, I. A.
J . Am. Chem. Soc. 1998, 120, 9205. (b) Kim, Y.-J .; Osakada, K.;
Yamamoto, A. J . Organomet. Chem. 1993, 452, 247. (c) Komiya, S.;
Shibue, A.; Ozaki, S. J . Organomet. Chem. 1987, 319, C31. (d) Komiya,
S.; Ozaki, S.; Shibue, A. J . Chem. Soc., Chem. Commun. 1986, 1555.
(12) (a) Albright, T. A.; Burdett, J . K.; Whangbo, M.-H. Orbital
Interactions in Chemistry; Wiley-Interscience: New York, 1985; p 372.
(b) Low, J . J .; Goddard, W. A., III. J . Am. Chem. Soc. 1986, 108, 6115.
(c) Low, J . J .; Goddard, W. A., III. Organometallics 1986, 5, 609. (d)
Tatsumi, K.; Hoffmann, R.; Yamamoto, A.; Stille, J . K. Bull. Chem.
Soc. J pn. 1981, 54, 1857.
∆Gq ) 23.2 kcal mol-1
.
The reaction rate clearly decreases as the electron-
withdrawing ability of the para substituent on the Ar
group increases (runs 2, 6, and 7), according to the
following Hammett equation (r ) 0.987): log(kY/kH) )
[-0.95(8)]σp + 0.00(2) (Figure 3). Similarly, the presence
of an electron-withdrawing substituent on the Ar′ group
on silicon effectively decelerates the reductive elimina-
tion (runs 2 and 11-13).
(13) (a) McGuinness, D. S.; Saendig, N.; Yates, B. F.; Cavell, K. J .
J . Am. Chem. Soc. 2001, 123, 4029. (b) Huang, J .; Haar, C. M.; Nolan,
S. P.; Marcone, J . E.; Moloy, K. G. Organometallics 1999, 18, 297. (c)
Calhorda, M. J .; Brown, J . M.; Cooley, N. A. Organometallics 1991,
10, 1431.

3596 Organometallics, Vol. 22, No. 17, 2003
Ozawa and Mori
Meth od B. The complex trans-PtMe(SiPh3)(PMe2Ph)2 (500
mg, 0.67 mmol) was placed in a 25 mL Schlenk tube, and the
system was purged with nitrogen gas. Benzene (8 mL) was
added, and the mixture was stirred to dissolve the complex.
PhCtCH (0.43 mL, 3.9 mmol) was added, and the solution
was stirred for 5 days at room temperature. 31P{1H} NMR
analysis revealed complete conversion of the starting methyl
complex (δ -3.6) into 1a (δ -11.5). The volatile material was
removed by pumping, and the resulting off-white solid of 1a
was purified similarly to method A (349 mg, 63% yield).
Complexes 1b-f were synthesized by method B and 1g-i
by method A. The former complexes were isolated by recrys-
tallization and characterized by NMR spectroscopy and el-
emental analysis as listed below. On the other hand, the latter
complexes were employed in the synthesis of cis isomers
without purification, but their formation was confirmed by
carbyl ligands; namely, the reaction is accelerated not
only by increasing nucleophilicity of one of the ligands
but also by increasing electrophilicity of the other
ligand.
In the present C-Si reductive elimination, since the
same tendency of substituent effect has been observed
for both the alkynyl and silyl ligands, it is reasonable
that the former type mechanism is operative with
simultaneous weakening of the Pt-C and Pt-Si bonds.15
In this case, electron-withdrawing substituents on the
Ar and Ar′ groups must stabilize the ground-state
species 2 via strengthening of the Pt-CtCAr and Pt-
SiAr′3 bonds.16 Although a bonding interaction between
the acetylenic carbon and the silicon in the transition
state is possibly enhanced by the electron-withdrawing
substituents as well, the energy change in the transition
state should be much smaller than that in the ground
state, owing to incomplete formation of the C-Si bond.
Hence, the substituent effects observed in this study are
reasonably interpreted.
31P{1H} NMR analysis (CD2Cl2, -20 °C): 1g, δ -10.7 (1J PtP
)
)
2604 Hz); 1h , δ -12.0 (1J PtP ) 2403 Hz); 1i, δ -12.2 (1J PtP
2374 Hz).
1
1a . H NMR (CD2Cl2, -20 °C): δ 1.57 (virtual triplet, J )
3.2 Hz, J PtH ) 31.7 Hz, 12H, PMe), 7.06-7.20 (m, 14H, Ph),
3
7.26-7.38 (m, 6H, Ph), 7.44 (m, 6H, Ph), 7.52 (m, 4H, Ph).
13C{1H} NMR (CD2Cl2, -20 °C): δ 16.4 (virtual triplet, J )
20 Hz, 2J PtC ) 42 Hz, PMe), 111.4 (s, 2J PtC ) 198 Hz, PhCtC),
Exp er im en ta l Section
2
1
125.6 (s, Ph), 126.3 (t, J PC ) 19 Hz, J PtC ) 758 Hz, PhCtC),
127.2 (s, SiPh), 127.5 (s, SiPh), 128.2 (virtual triplet, J ) 5
Gen er a l P r oced u r e a n d Ma ter ia ls. All manipulations
were carried out under a nitrogen atmosphere using conven-
tional Schlenk techniques. Nitrogen gas was dried by passing
through P2O5 (Merck, SICAPENT). NMR spectra were re-
corded on J EOL A400 and Varian Mercury 300 spectrometers.
Chemical shifts are reported in δ (ppm) referenced to an
internal SiMe4 standard for1H and 13C NMR and to an external
85% H3PO4 standard for 31P NMR. THF, Et2O, benzene, and
hexane were dried over sodium benzophenone ketyl and
distilled just before using. CH2Cl2 was dried over CaH2 and
distilled just before using. Benzene-d6 was dried over LiAlH4,
vacuum-transferred, and stored under a nitrogen atmosphere.
3
Hz, PPh), 128.3 (s, Ph), 128.4 (s, J PtC ) 23 Hz, Ph), 130.0 (s,
PPh), 130.7 (s, Ph), 131.8 (virtual triplet, J ) 6 Hz, PPh), 136.4
2
3
(virtual triplet, J ) 28 Hz, J PtP ) 28 Hz, PPh), 137.3 (s, J PtC
) 17 Hz, SiPh), 145.7 (s, J PtC ) 30 Hz, SiPh). 31P{1H} NMR
(CD2Cl2, -20 °C): δ -11.4 (s, J PtP ) 2551 Hz). Anal. Calcd
for C42H42P2PtSi: C, 60.64; H, 5.09. Found: C, 60.41; H, 4.90.
2
1
1
1b. Yield 56%, colorless crystals. H NMR (CD2Cl2, 20 °C):
δ 1.59 (virtual triplet, J ) 3.4 Hz, 3J PtH ) 31.7 Hz, 12H, PMe),
3
3.74 (s, 3H, MeO), 6.71 (d, J HH ) 8.3 Hz, 2H, Ar), 7.02 (d,
3J HH ) 8.3 Hz, 2H, Ar), 7.05-7.20 (m, 9H, Ph), 7.25-7.38 (m,
3
18
trans-PtCl(SiAr3)(PMe2Ph)217 and trans-PtMe(SiPh3)(PMePh2)2
6H, Ph), 7.48 (d, 6H, J HH ) 6.8 Hz, Ph), 7.56 (m, 4H, Ph).
13C{1H} NMR (CD2Cl2, 20 °C): δ 16.9 (virtual triplet, J ) 21
were prepared according to the literature. All other compounds
used in this study were obtained from commercial sources and
used without further purification.
P r ep a r a tion of tr a n s-P t(CtCAr )(SiAr ′3)(P Me2P h )2 (1).
The title compounds were prepared either by the reaction of
trans-PtCl(SiAr′3)(PMe2Ph)2 with ArCtCMgCl in THF (method
A) or by the reaction of trans-PtMe(SiAr′3)(PMe2Ph)2 with
ArCtCH in benzene (method B). Typical procedures are as
follows.
Meth od A. To a solution of trans-PtCl(SiPh3)(PMe2Ph)2 (500
mg, 0.65 mmol) in THF (8 mL) was added a THF solution of
PhCtCMgCl (1.44 M; 0.50 mL, 0.72 mmol) at room temper-
ature. The mixture was stirred for 30 min and cooled to -20
°C. Methanol (1 mL) was added, and the solution was
concentrated to dryness. The residue was extracted with
benzene (4 mL × 3), and the extracts were filtered through a
short Celite column. The filtrate was concentrated to dryness
by pumping, and the residue was dissolved in CH2Cl2 (ca. 2
mL), slowly layered with Et2O (20 mL), and allowed to stand
at -20 °C for 1 day to give colorless crystals of 1a (300 mg,
55% yield).
2
2
Hz, J PtC ) 43 Hz, PMe), 55.7 (s, MeO), 111.4 (s, J PtC ) 198
3
Hz, ArCtC), 114.0 (s, Ar), 121.4 (s, J PtC ) 16 Hz, Ar), 124.0
(t, 2J PC ) 19 Hz, ArCtC), 127.4 (s, SiPh), 127.7 (s, SiPh), 128.4
(virtual triplet, J ) 5 Hz, PPh), 130.2 (s, PPh), 132.1 (s, Ar),
132.2 (virtual triplet, J ) 6 Hz, PPh), 137.0 (virtual triplet, J
2
3
) 29 Hz, J PtC ) 28 Hz, PPh), 137.6 (s, J PtC ) 17 Hz, SiPh),
146.3 (s, 2J PtC ) 30 Hz, SiPh), 158.1 (s, Ar). 31P{1H} NMR (CD2-
Cl2, 20 °C): δ -11.4 (s, 1J PtP ) 2576 Hz). Anal. Calcd for C43H44
-
OP2PtSi: C, 59.92; H, 5.15. Found: C, 59.80; H, 5.19.
1c. Yield 74%, white solid. 1H NMR (CD2Cl2, 20 °C): δ 1.60
3
(virtual triplet, J ) 3.4 Hz, J PtH ) 31.2 Hz, 12H, PMe), 2.28
(s, 3H, Me), 7.01 (m, 4H, Ar), 7.06-7.25 (m, 9H, Ph), 7.25-
7.40 (m, 6H, Ph), 7.45-7.63 (m, 10H, Ph). 13C{1H} NMR (CD2-
2
Cl2, 20 °C): δ 16.8 (virtual triplet, J ) 21 Hz, J PtC ) 41 Hz,
PMe), 21.6 (s, Me), 111.8 (s, 2J PtC ) 197 Hz, ArCtC), 125.3 (t,
2J PC ) 18 Hz, ArCtC), 125.9 (s, J PtC ) 18 Hz, Ar), 127.4 (s,
3
SiPh), 127.7 (s, SiPh), 128.4 (virtual triplet, J ) 5 Hz, PPh),
129.2 (s, Ar), 130.2 (s, PPh), 130.8 (s, Ar), 132.2 (virtual triplet,
J ) 6 Hz, PPh), 135.6 (s, Ar), 136.9 (virtual triplet, J ) 28
2
3
Hz, J PtC ) 28 Hz, PPh), 137.6 (s, J PtC ) 18 Hz, SiPh), 146.3
(s, 2J PtC ) 30 Hz, SiPh). 31P{1H} NMR (CD2Cl2, 20 °C): δ -11.4
1
(14) Migratory reductive elimination has been proposed also for the
reactions giving C-N, C-O, and C-S bonds. (a) Reference 11a. (b)
Widenhoefer, R. A.; Buchwald, S. L. J . Am. Chem. Soc. 1998, 120, 6504.
(c) Widenhoefer, R. A.; Zhong, H. A.; Buchwald, S. L. J . Am. Chem.
Soc. 1997, 119, 6787. (d) Driver, M. S.; Hartwig, J . F. J . Am. Chem.
Soc. 1997, 119, 8232. (e) Mann, G.; Hartwig, J . F. J . Am. Chem. Soc.
1996, 118, 13109. (f) Baranano, D.; Hartwig, J . F. J . Am. Chem. Soc.
1995, 117, 2937.
(15) This mechanism is consistent with the slightly positive activa-
tion entropy (10(2) eu) observed for 2a .
(16) Yamamoto, A. Organotransition Metal Chemistry. Fundamental
Concepts and Applications; Wiley-Interscience: New York, 1986; p 286.
(17) Chatt, J .; Eaborn, C.; Ibekwe, S. D.; Kapoor, P. N. J . Chem.
Soc. A 1970, 1343.
(s, J PtP ) 2572 Hz). Anal. Calcd for C43H44P2PtSi: C, 61.05;
H, 5.24. Found: C, 60.91; H, 5.10.
1d . Yield 75%, white solid. 1H NMR (CD2Cl2, 20 °C): δ 1.57
3
(virtual triplet, J ) 3.4 Hz, J PtH ) 31.7 Hz, 12H, PMe), 7.00
3
(d, J HH ) 8.8 Hz, 2H, Ar), 7.07-7.25 (m, 11H, Ar and Ph),
7.29 (m, 4H, Ph), 7.35 (m, 2H, Ph), 7.48 (m, 6H, Ph), 7.55 (m,
4H, Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ 16.8 (virtual triplet,
2
J ) 21 Hz, J PtC ) 41 Hz, PMe), 110.7 (s, ArCtC), 127.5 (s,
SiPh), 127.7 (s, SiPh), 128.5 (virtual triplet, J ) 5 Hz, PPh),
128.6 (s, Ar), 130.2 (s, PPh), 131.1 (s, Ar), 132.2 (virtual triplet,
J ) 7 Hz, PPh), 132.2 (s, Ar), 136.8 (virtual triplet, J ) 28
2
3
(18) Ozawa, F.; Hikida, T. Organometallics 1996, 15, 4501.
Hz, J PtC ) 28 Hz, PPh), 137.6 (s, J PtC ) 17 Hz, SiPh), 146.1

cis-Alkynyl(silyl)platinum(II) Complexes
Organometallics, Vol. 22, No. 17, 2003 3597
2
3
3
(s, J PtC ) 28 Hz, SiPh). One acetylenic carbon and one C6H4-
6.49 (d, J HH ) 8.8 Hz, 2H, Ar), 6.55 (d, J HH ) 8.8 Hz, 2H,
Ar), 7.17-7.48 (m, 19H, Ph), 7.70 (m, 6H, Ph). 13C{1H} NMR
(CD2Cl2, -20 °C): δ 14.7 (d, 1J PC ) 28 Hz, 2J PtC ) 26 Hz, PMe),
16.2 (dd, J PC ) 36 and 5 Hz, 2J PtC ) 35 Hz, PMe), 55.3 (s, OMe),
Cl group carbon were not detected. 31P{1H} NMR (CD2Cl2, 20
°C): δ -11.3 (s, J PtP ) 2573 Hz). Anal. Calcd for C42H41P2-
PtSiCl: C, 58.23; H, 4.77. Found: C, 58.28; H, 4.74.
1
2
1
110.9 (dd, J PC ) 127 and 20 Hz, ArCtC), 113.0 (s, Ar), 115.5
1e. Yield 76%, white crystalline solid. H NMR (CD2Cl2, 20
(dd, 3J PC ) 31 and 2 Hz, ArCtC), 120.8 (s, Ar), 127.1 (s, SiPh),
3
°C): δ 1.56 (virtual triplet, J ) 3.7 Hz, J PtH ) 31.7 Hz, 12H,
3
3
3
127.4 (s, SiPh), 128.5 (d, J PC ) 10 Hz, PPh), 128.6 (d, J PC
)
PMe), 6.93 (d, J HH ) 8.3 Hz, 2H, Ar), 7.09 (m, 6H, Ph), 7.16
11 Hz, PPh), 129.6 (s, PPh), 130.4 (s, PPh), 130.9 (d, 2J PC ) 10
(m, 3H, Ph), 7.28 (m, 6H, Ar and Ph), 7.35 (m, 2H, Ph), 7.47
2
3
(m, 6H, Ph), 7.54 (m, 4H, Ph). 13C{1H} NMR (CD2Cl2, 20 °C):
Hz, PPh), 131.5 (d, J PC ) 12 Hz, J PtC ) 23 Hz, PPh), 132.1
3
2
(s, Ar), 137.2 (s, J PtC ) 20 Hz, SiPh), 137.4 (d, PPh), 137.8
δ 16.8 (virtual triplet, J ) 20 Hz, J PtC ) 43 Hz, PMe), 110.7
(dd, J PC ) 52 and 5 Hz, PPh), 145.6 (d, 3J PC ) 5 Hz, 2J PtC ) 45
Hz, SiPh), 157.4 (s, Ar). 31P{1H} NMR (CD2Cl2, -20 °C): δ
(s, ArCtC), 119.2 (s, Ar), 127.5 (s, SiPh), 127.7 (s, SiPh), 128.5
(virtual triplet, J ) 5 Hz, PPh), 130.2 (s, PPh), 131.5 (s, Ar),
132.1 (virtual triplet, J ) 7 Hz, PPh), 132.5 (s, Ar), 136.8
2
1
2
-14.3 (d, J PP ) 23 Hz, J PtP ) 2663 Hz), -6.3 (d, J PP ) 23
1
2
2
3
Hz, J PtP ) 1137 Hz, J SiP ) 179 Hz). Anal. Calcd for C43H44
-
(virtual triplet, J ) 28 Hz, J PtC ) 28 Hz, PPh), 137.6 (s, J PtC
2
OP2PtSi: C, 59.92; H, 5.15. Found: C, 59.66; H, 4.88.
) 17 Hz, SiPh), 146.1 (s, J PtC ) 28 Hz, SiPh). One acetylenic
carbon and one C6H4Br group carbon were not detected. 31P-
{1H} NMR (CD2Cl2, 20 °C): δ -11.3 (s, 1J PtP ) 2573 Hz). Anal.
Calcd for C42H41P2PtSiBr: C, 55.39; H, 4.54. Found: C, 55.18;
H, 4.41.
1
2c. Yield 65%, pale yellow crystals. H NMR (CD2Cl2, -20
2
3
°C): δ 1.03 (d, J PH ) 9.3 Hz, J PtH ) 28.3 Hz, 6H, PMe), 1.67
(d, 2J PH ) 8.8 Hz, 3J PtH ) 16.6 Hz, 6H, PMe), 2.18 (s, 3H, Me),
3
3
6.51 (d, J HH ) 7.6 Hz, 2H, Ar), 6.85 (d, J HH ) 7.6 Hz, 2H,
Ar), 7.15-7.50 (m, 19H, Ph), 7.71 (m, 6H, Ph). 13C{1H} NMR
(CD2Cl2, -20 °C): δ 14.7 (d, 1J PC ) 28 Hz, 2J PtC ) 26 Hz, PMe),
16.2 (dd, J PC ) 36 and 5 Hz, 2J PtC ) 36 Hz, PMe), 21.3 (s, Me),
1f. Yield 39%, pale yellow crystals. 1H NMR (CD2Cl2, 20
°C): δ 1.56 (virtual triplet, J ) 3.7 Hz, J PtH ) 31.7 Hz, 12H,
PMe), 7.10 (m, 8H, Ar and Ph), 7.17 (m, 3H, Ph), 7.29 (m, 4H,
Ph), 7.36 (m, 2H, Ph), 7.42 (d, 3J HH ) 8.3 Hz, 2H, Ar), 7.47 (m,
6H, Ph), 7.54 (m, 4H, Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ
3
2
3
112.4 (dd, J PC ) 127 and 19 Hz, ArCtC), 115.9 (dd, J PC
)
2
3
29 and 2 Hz, J PtC ) 317 Hz, ArCtC), 125.3 (s, J PtC ) 24 Hz,
Ar), 127.1 (s, SiPh), 127.4 (s, SiPh), 128.4 (s, Ar), 128.5 (d, 3J PC
2
16.8 (virtual triplet, J ) 21 Hz, J PtC ) 43 Hz, PMe), 108.5 (s,
Ar), 111.3 (s, J PtC ) 194 Hz, ArCtC), 119.9 (s, CN), 127.5 (s,
3
2
) 10 Hz, PPh), 128.6 (d, J PC ) 10 Hz, PPh), 129.6 (s, PPh),
130.4 (s, PPh), 130.7 (s, Ar), 130.9 (d, 2J PC ) 10 Hz, PPh), 131.4
SiPh), 127.9 (s, SiPh), 128.6 (virtual triplet, J ) 5 Hz, PPh),
130.3 (s, PPh), 131.5 (s, Ar), 132.1 (virtual triplet, J ) 7 Hz,
2
3
(d, J PC ) 12 Hz, J PtC ) 23 Hz, PPh), 135.2 (s, Ar), 137.2 (s,
3J PtC ) 20 Hz, SiPh), 137.2 (d, J PC ) 60 Hz, PPh), 137.8 (dd,
1
3
2
PPh), 132.3 (s, Ar), 133.7 (s, J PtC ) 20 Hz, Ar), 135.7 (t, J PC
J PC ) 51 and 5 Hz, PPh), 145.7 (d, 3J PC ) 6 Hz, 2J PtC ) 46 Hz,
) 18 Hz, ArCtC), 136.7 (virtual triplet, J ) 28 Hz, 2J PtC ) 28
SiPh). 31P{1H} NMR (CD2Cl2, -20 °C): δ -14.1 (d, J PP ) 23
2
3
2
Hz, PPh), 137.6 (s, J PtC ) 17 Hz, SiPh), 146.0 (s, J PtC ) 28
1
2
1
Hz, SiPh). 31P{1H} NMR (CD2Cl2, 20 °C): δ -11.2 (s, J PtP
)
1
Hz, J PtP ) 2665 Hz), -6.0 (d, J PP ) 23 Hz, J PtP ) 1134 Hz,
2J SiP ) 177 Hz). Anal. Calcd for C43H44P2PtSi: C, 61.05; H,
5.24. Found: C, 60.85; H, 5.13.
2570 Hz). Anal. Calcd for C43H41NP2PtSi: C, 60.27; H, 4.82;
N, 1.63. Found: C, 59.91; H, 4.67; N, 1.87.
1
P r ep a r a tion of cis-P t(CtCAr )(SiAr ′3)(P Me2P h )2 (2). A
typical procedure is reported for 2a . The trans isomer 1a (130
mg, 0.156 mmol) was placed in a 25 mL Schlenk tube and
dissolved in CH2Cl2 (4 mL) at room temperature. The solution
was cooled to -20 °C and saturated with CO by bubbling. The
system was allowed to stand for 4 h at the same temperature,
and the conversion of 1a was confirmed by 31P{1H} NMR
spectroscopy. The solution was concentrated to dryness by
pumping to yield a yellow solid, which was washed with cold
Et2O and dried under vacuum. The crude product was dis-
solved in CH2Cl2 (ca. 0.4 mL) at -20 °C, layered carefully with
Et2O (2 mL), and allowed to stand at -70 °C to give pale yellow
crystals of 2a (76.1 mg, 59% yield). This product contained
0.5 equiv of Et2O in the crystal, as confirmed by 1H NMR
spectroscopy.
2d . Yield 73%, pale yellow crystals. H NMR (CD2Cl2, -20
2
3
°C): δ 1.04 (d, J PH ) 9.2 Hz, J PtH ) 28.0 Hz, 6H, PMe), 1.64
2
3
3
(d, J PH ) 8.4 Hz, J PtH ) 17.2 Hz, 6H, PMe), 6.47 (d, J HH
)
8.8 Hz, 2H, Ar), 6.97 (d, 3J HH ) 8.8 Hz, 2H, Ar), 7.18-7.48 (m,
19H, Ph), 7.70 (m, 6H, Ph). 13C{1H} NMR (CD2Cl2, -20 °C):
1
2
δ 14.7 (d, J PC ) 26 Hz, J PtC ) 26 Hz, PMe), 16.1 (dd, J PC
)
2
3
36 and 4 Hz, J PtC ) 36 Hz, PMe), 114.7 (dd, J PC ) 30 and 3
2
Hz, ArCtC), 115.6 (dd, J PC ) 126 and 18 Hz, ArCtC), 126.9
(s, 3J PtC ) 24 Hz, Ar), 127.2 (s, SiPh), 127.5 (s, SiPh), 127.8 (s,
3
3
Ar), 128.6 (d, J PC ) 8 Hz, PPh), 128.7 (d, J PC ) 10 Hz, PPh),
2
3
129.7 (s, PPh), 130.5 (s, PPh), 131.0 (d, J PC ) 10 Hz, J PtC
)
27 Hz, PPh), 131.4 (d, 2J PC ) 12 Hz, 3J PtC ) 23 Hz, PPh), 132.2
3
(s, Ar), 132.2 (s, Ar), 137.1 (s, J PtC ) 20 Hz, SiPh), 137.2 (d,
3
PPh), 137.6 (dd, J PC ) 51 and 5 Hz, PPh), 145.4 (d, J PC ) 5
Hz, J PtC ) 45 Hz, SiPh). 31P{1H} NMR (CD2Cl2, -20 °C): δ
2
2
1
2
2a . 1H NMR (CD2Cl2, -20 °C): δ 0.97 (d, J PH ) 8.8 Hz,
2
-14.2 (d, J PP ) 23 Hz, J PtP ) 2664 Hz), -6.1 (d, J PP ) 23
Hz, 1J PtP ) 1139 Hz, 2J SiP ) 177 Hz). Anal. Calcd for C42H41P2-
PtSiCl: C, 58.23; H, 4.77. Found: C, 58.03; H, 4.64.
3J PtH ) 28.3 Hz, 6H, PMe), 1.60 (d, 2J PH ) 9.3 Hz, 3J PtH ) 16.6
Hz, 6H, PMe), 6.53 (m, 2H, Ph), 6.94 (m, 3H, Ph), 7.12-7.43
3
1
(m, 19H, Ph), 7.65 (m, 6H, Ph); 1.08 (t, J HH ) 6.8 Hz, 3H,
2e. Yield 59%, pale yellow crystals. H NMR (CD2Cl2, -20
0.5‚Et2O), 3.35 (q, 3J HH ) 6.8 Hz, 2H, 0.5 Et2O). 13C{1H} NMR
2
3
°C): δ 1.03 (d, J PH ) 9.2 Hz, J PtH ) 28.6 Hz, 6H, PMe), 1.63
(CD2Cl2, -20 °C): δ 14.7 (d, 1J PC ) 26 Hz, 2J PtC ) 26 Hz, PMe),
2
3
3
(d, J PH ) 8.4 Hz, J PtH ) 16.8 Hz, 6H, PMe), 6.39 (d, J HH
)
2
8.8 Hz, 2H, Ar), 7.11 (d, 3J HH ) 8.8 Hz, 2H, Ar), 7.18-7.47 (m,
16.1 (dd, J PC ) 35 and 5 Hz, J PtC ) 35 Hz, PMe), 113.7 (dd,
2J PC ) 126 and 21 Hz, J PtC ) 1082 Hz, PhCtC), 115.9 (dd,
1
19H, Ph), 7.68 (m, 6H, Ph). 13C{1H} NMR (CD2Cl2, -20 °C):
3J PC ) 32 and 2 Hz, J PtC ) 318 Hz, PhCtC), 125.3 (s, Ph),
2
1
2
δ 14.7 (d, J PC ) 28 Hz, J PtC ) 23 Hz, PMe), 16.1 (dd, J PC
)
3
2
3
127.1 (s, SiPh), 127.4 (s, SiPh), 127.7 (s, Ph), 128.3 (s, J PtC
)
36 and 5 Hz, J PtC ) 36 Hz, PMe), 114.8 (dd, J PC ) 31 and 5
3
3
2
24 Hz, Ph), 128.5 (d, J PC ) 10 Hz, PPh), 128.7 (d, J PC ) 11
Hz, ArCtC), 116.0 (dd, J PC ) 128 and 18 Hz, ArCtC), 118.7
2
3
Hz, PPh), 129.6 (s, PPh), 130.5 (s, PPh), 130.9 (d, J PC ) 10
(s, Ar), 127.1 (s, SiPh), 127.5 (s, SiPh), 128.5 (d, J PC ) 8 Hz,
2
3
3
Hz, PPh), 131.4 (d, J PC ) 12 Hz, J PtC ) 23 Hz, PPh), 137.1
PPh), 128.7 (d, J PC ) 10 Hz, PPh), 129.7 (s, PPh), 130.5 (s,
3
PPh), 130.7 (s, Ar), 130.9 (d, 2J PC ) 10 Hz, PPh), 131.4 (d, 2J PC
(s, J PtC ) 20 Hz, SiPh), 137.2 (d, PPh), 137.7 (dd, J PC ) 52
3
2
3
3
and 5 Hz, PPh), 145.5 (d, J PC ) 7 Hz, J PtC ) 43 Hz, SiPh);
) 12 Hz, J PtC ) 23 Hz, PPh), 132.5 (s, Ar), 137.1 (s, J PtC
)
15.5 (s, Et2O), 66.1 (s, Et2O). 31P{1H} NMR (CD2Cl2, -20 °C):
20 Hz, SiPh), 137.2 (d, PPh), 137.6 (dd, J PC ) 51 and 5 Hz,
PPh), 145.4 (d, 3J PC ) 5 Hz, 2J PtC ) 46 Hz, SiPh). One C6H4Br
group carbon was not detected. 31P{1H} NMR (CD2Cl2, -20
2
1
2
δ -14.2 (d, J PP ) 23 Hz, J PtP ) 2667 Hz), -6.1 (d, J PP ) 23
Hz, 1J PtP ) 1137 Hz, 2J SiP ) 177 Hz). Anal. Calcd for C42H42P2-
PtSi‚0.5C4H10O: C, 60.82; H, 5.45. Found: C, 60.60; H, 5.33.
2
1
2
°C): δ -14.2 (d, J PP ) 23 Hz, J PtP ) 2667 Hz), -6.1 (d, J PP
1
1
2
2b. Yield 48%, pale yellow crystals. H NMR (CD2Cl2, -20
) 23 Hz, J PtP ) 1139 Hz, J SiP ) 177 Hz). Anal. Calcd for
C42H41P2PtSiBr‚0.5CH2Cl2: C, 53.55; H, 4.44. Found: C, 53.12;
H, 4.14.
2
3
°C): δ 1.03 (d, J PH ) 8.8 Hz, J PtH ) 28.3 Hz, 6H, PMe), 1.67
(d, 2J PH ) 8.8 Hz, 3J PtH ) 16.6 Hz, 6H, PMe), 3.68 (s, 3H, MeO),

3598 Organometallics, Vol. 22, No. 17, 2003
Ozawa and Mori
2
1
2
2f. Yield 70%, yellow crystals. 1H NMR (CD2Cl2, -20 °C):
-6.2 (d, J PP ) 23 Hz, J PtP ) 1281 Hz, J SiP ) 208 Hz). Anal.
Calcd for C45H39P2PtSiF9: C, 52.18; H, 3.79. Found: C, 51.93;
H, 3.72.
2
3
δ 1.06 (d, J PH ) 8.8 Hz, J PtH ) 28.0 Hz, 6H, PMe), 1.62 (d,
3
3
2J PH ) 8.3 Hz, J PtH ) 16.1 Hz, 6H, PMe), 6.57 (d, J HH ) 7.8
Hz, 2H, Ar), 7.15-7.50 (m, 21H, Ph), 7.68 (m, 6H, Ph). 13C-
Kin etic Stu d y of Red u ctive Elim in a tion . A typical
procedure (run 2 in Table 1) is as follows. Complex 2a (15.0
mg, 18.0 mmol) and MeSiPh3 (1.7 mg, 6.2 mmol) as an internal
standard were placed in an NMR sample tube with a rubber
septum cap, and the system was purged with nitrogen gas at
room temperature. Benzene-d6 (0.60 mL) was added, and the
sample tube was placed in an NMR sample probe controlled
to 35.0(1) °C. The time course of the reductive elimination was
followed by measuring the relative peak integration of the
methyl proton signals of the product Pt(PhCtCSiPh3)(PMe2-
Ph)2 (3a ) (δ 0.93) and MeSiPh3 (δ 0.73).
Complex 3a was isolated and characterized by NMR spec-
troscopy and elemental analysis. Thus, the solution of 2a (50
mg, 60 mmol) in benzene (2 mL) was heated at 45 °C for 3 h.
The solution was concentrated to dryness. Et2O (0.5 mL) and
pentane (5 mL) were added, and the resulting pale yellow
suspension was stirred at room temperature for 1 h. The
precipitate was collected by filtration and dried under vacuum
(23 mg, 46% yield).
{1H} NMR (CD2Cl2, -20 °C): δ 14.7 (d, J PC ) 28 Hz, J PtC
)
1
2
23 Hz, PMe), 16.1 (dd, J PC ) 36 and 5 Hz, 2J PtC ) 36 Hz, PMe),
107.6 (s, Ar), 115.3 (dd, 3J PC ) 30 and 4 Hz, ArCtC), 119.9 (s,
CN), 122.7 (dd, 2J PC ) 126 and 19 Hz, ArCtC), 127.2 (s, SiPh),
3
3
127.6 (s, SiPh), 128.6 (d, J PC ) 8 Hz, PPh), 128.8 (d, J PC
)
10 Hz, PPh), 129.8 (s, PPh), 130.6 (s, PPh), 131.0 (d, 2J PC ) 10
2
Hz, PPh), 131.2 (s, Ar), 131.5 (d, J PC ) 12 Hz, PPh), 131.5 (s,
3
3
Ar), 133.1 (s, J PtC ) 22 Hz, Ar), 137.0 (d, PPh), 137.1 (s, J PtC
) 18 Hz, SiPh), 137.5 (dd, J PC ) 51 and 4 Hz, PPh), 145.1 (d,
3J PC ) 5 Hz, 2J PtC ) 45 Hz, SiPh). 31P{1H} NMR (CD2Cl2, -20
2
1
2
°C): δ -14.2 (d, J PP ) 23 Hz, J PtP ) 2664 Hz), -6.1 (d, J PP
1
2
) 23 Hz, J PtP ) 1146 Hz, J SiP ) 174 Hz). Anal. Calcd for
43H41NP2PtSi: C, 60.27; H, 4.82; N, 1.63. Found: C, 59.95;
H, 4.67; N, 1.78.
2g. Yield 55%, pale yellow crystals. H NMR (CD2Cl2, -30
C
1
2
3
°C): δ 1.05 (d, J PH ) 8.8 Hz, J PtH ) 28.0 Hz, 6H, PMe), 1.67
(d, 2J PH ) 8.0 Hz, 3J PtH ) 16.0 Hz, 6H, PMe), 3.75 (s, 9H, OMe),
3
3
6.66 (d, J HH ) 6.8 Hz, 2H, Ph), 6.79 (d, J HH ) 7.2 Hz, 6H,
Ar), 7.03 (m, 3H, Ph), 7.20-7.65 (m, 16H, Ph). 13C{1H} NMR
(CD2Cl2, -30 °C): δ 14.6 (d, 1J PC ) 28 Hz, 2J PtC ) 23 Hz, PMe),
16.0 (dd, J PC ) 35 and 4 Hz, 2J PtC ) 40 Hz, PMe), 55.1 (s, OMe),
112.5 (s, SiAr), 113.9 (dd, 2J PC ) 127 and 20 Hz, PhCtC), 115.5
3a . 1H NMR (CD2Cl2, 20 °C): δ 1.24 (d, 2J PH ) 6.8 Hz, 3J PtH
) 28.8 Hz, 6H, PMe), 1.54 (d, J PH ) 6.8 Hz, J PtH ) 30.4 Hz,
6H, PMe), 6.96 (m, 5H, Ph), 7.20-7.38 (m, 15H, Ph), 7.50-
7.62 (m, 4H, Ph), 7.69 (m, 6H, Ph). 13C{1H} NMR (CD2Cl2, 20
2
3
3
(dd, J PC ) 31 and 3 Hz, PhCtC), 125.2 (s, Ph), 127.6 (s, Ph),
2
°C): δ 19.6 (dd, J PC ) 23 and 8 Hz, J PtC ) 46 Hz, PMe), 20.5
128.3 (s, 3J PtC ) 24 Hz, Ph), 128.4 (d, 3J PC ) 8 Hz, PPh), 128.6
(dd, J PC ) 22 and 10 Hz, 2J PtC ) 50 Hz, PMe), 115.9 (d, 2J PC
)
3
(d, J PC ) 10 Hz, PPh), 129.4 (s, PPh), 130.4 (s, PPh), 130.7
43 Hz, PhCtC), 126.1 (s, Ph), 127.8 (s, Ph), 128.0 (s, SiPh),
2
2
(d, J PC ) 10 Hz, PPh), 130.8 (s, Ph), 131.4 (d, J PC ) 12 Hz,
3J PtC ) 23 Hz, PPh), 136.5 (d, 3J PC ) 5 Hz, 2J PtC ) 46 Hz, SiAr),
137.3 (dd, J PC ) 41 and 5 Hz, PPh), 137.4 (d, PPh), 138.2 (s,
3J PtC ) 18 Hz, SiAr), 159.0 (s, SiAr). 31P{1H} NMR (CD2Cl2,
3
4
3
128.5 (d, J PC ) 8 Hz, PPh), 129.4 (d, J PC ) 5 Hz, J PtC ) 26
2
Hz, SiPh), 129.5 (s, SiPh, PPh, and Ph), 131.4 (d, J PC ) 12
Hz, 3J PtC ) 23 Hz, PPh), 131.6 (d, 2J PC ) 10 Hz, 3J PtC ) 23 Hz,
PPh), 136.5 (s, SiPh), 137.5 (s, Ph), 141.4 (dd, J PC ) 34 and 8
2
1
-30 °C): δ -13.5 (d, J PP ) 23 Hz, J PtP ) 2667 Hz), -5.6 (d,
2
Hz, PPh), 141.7 (dd, J PC ) 48 and 8 Hz, PPh), 154.6 (dd, J PC
1
2
2J PP ) 23 Hz, J PtP ) 1080 Hz, J SiP ) 176 Hz). Anal. Calcd
for C45H48O3P2PtSi: C, 58.62; H, 5.25. Found: C, 58.58; H,
5.23.
) 51 and 5 Hz, CtCSi). 31P{1H} NMR (CD2Cl2, 20 °C): δ -12.5
2
1
2
(d, J PP ) 37 Hz, J PtP ) 3337 Hz), -12.8 (d, J PP ) 37 Hz,
1J PtP ) 3563 Hz). Anal. Calcd for C42H42P2PtSi: C, 60.64; H,
5.09. Found: C, 60.54; H, 5.02.
2h . Yield 77%, white crystalline solid. 1H NMR (CD2Cl2, -30
2
3
°C): δ 1.05 (d, J PH ) 8.8 Hz, J PtH ) 27.3 Hz, 6H, PMe), 1.66
The reductive elimination products 3b-h were not isolated,
(d, 2J PH ) 7.3 Hz, 3J PtH ) 16.6 Hz, 6H, PMe), 2.31 (s, 9H, Me),
while their formation was confirmed by H, 13C, and 31P{1H}
1
3
6.56 (d, J HH ) 6.3 Hz, 2H, Ar), 6.95-7.65 (m, 25H, Ar and
NMR spectroscopy.
Ph). 13C{1H} NMR (CD2Cl2, -30 °C): δ 14.5 (d, J PC ) 26 Hz,
1
3b. 1H NMR (CD2Cl2, 20 °C): δ 1.23 (d, 2J PH ) 6.8 Hz, 3J PtH
2J PtC ) 26 Hz, PMe), 15.9 (dd, J PC ) 35 and 5 Hz, J PtC ) 40
2
2
3
Hz, PMe), 21.4 (s, Me), 113.8 (dd, 2J PC ) 126 and 21 Hz, PhCt
) 27.8 Hz, 6H, PMe), 1.56 (d, J PH ) 7.3 Hz, J PtH ) 29.8 Hz,
3
C), 115.2 (dd, 3J PC ) 33 and 3 Hz, PhCtC), 125.2 (s, Ph), 127.6
6H, PMe), 3.68 (s, 3H, OMe), 6.46 (d, J HH ) 8.3 Hz, 2H, Ar),
3
6.82 (d, J HH ) 8.3 Hz, 2H, Ar), 7.10-7.75 (m, 25H, Ph). 13C-
3
(s, Ph), 127.8 (s, SiPh), 128.4 (d, J PC ) 8 Hz, PPh), 128.6 (d,
{1H} NMR (CD2Cl2, 20 °C): δ 19.8 (dd, J PC ) 22 and 10 Hz,
3J PC ) 10 Hz, PPh), 129.4 (s, PPh), 130.4 (s, PPh), 130.6 (d,
2J PtC ) 45 Hz, PMe), 20.5 (dd, J PC ) 22 and 10 Hz, J PtC ) 45
2
2J PC ) 9 Hz, PPh), 130.9 (s, Ph), 131.4 (d, J PC ) 10 Hz, J PtC
2
3
2
3
Hz, PMe), 55.6 (s, OMe), 114.0 (s, Ar), 114.3 (d, J PC ) 50 Hz,
) 22 Hz, PPh), 137.0 (s, SiAr), 137.0 (s, J PtC ) 20 Hz, SiAr),
ArCtC), 128.0 (s, SiPh), 128.4 (d, 3J PC ) 8 Hz, PPh), 129.5 (s,
137.2 (d, PPh), 137.8 (dd, J PC ) 51 and 5 Hz, PPh), 142.0 (d,
4
3
3J PC ) 5 Hz, J PtC ) 46 Hz, SiAr). One Ph carbon was not
2
SiPh), 129.5 (d, J PC ) 5 Hz, J PtC ) 26 Hz, SiPh), 129.6 (s,
2
3
detected. 31P{1H} NMR (CD2Cl2, -30 °C): δ -14.2 (d, J PP
)
2
PPh), 131.4 (d, J PC ) 12 Hz, J PtC ) 23 Hz, PPh), 131.6 (d,
2J PC ) 10 Hz, 3J PtC ) 23 Hz, PPh), 131.6 (s, Ar), 136.5 (s, SiPh),
137.7 (s, Ar), 141.5 (dd, J PC ) 34 and 8 Hz, PPh), 141.7 (dd,
J PC ) 48 and 8 Hz, PPh), 158.1 (s, Ar), 154.0 (d, 2J PC ) 51 Hz,
1
2
1
23 Hz, J PtP ) 2661 Hz), -5.8 (d, J PP ) 23 Hz, J PtP ) 1095
2
Hz, J SiP ) 176 Hz). Anal. Calcd for C45H48P2PtSi: C, 61.84;
H, 5.54. Found: C, 61.22; H, 5.16.
CtCSi). 31P{1H} NMR (CD2Cl2, 20 °C): δ -12.4 (d, J PP ) 38
2
1
2i. Yield 78%, pale yellow crystals. H NMR (CD2Cl2, -20
1
2
1
2
3
Hz, J PtP ) 3319 Hz), -12.7 (d, J PP ) 38 Hz, J PtP ) 3570
°C): δ 1.11 (d, J PH ) 8.8 Hz, J PtH ) 28.8 Hz, 6H, PMe), 1.80
(d, 2J PH ) 8.8 Hz, 3J PtH ) 18.4 Hz, 6H, PMe), 6.45 (m, 2H, Ar),
7.00 (m, 3H, Ph), 7.25-7.51 (m, 16H, Ph), 7.65 (m, 6H, Ph).
13C{1H} NMR (CD2Cl2, -20 °C): δ 15.0 (d, 1J PC ) 30 Hz, 2J PtC
Hz).
3c. 1H NMR (CD2Cl2, 20 °C): δ 1.23 (d, 2J PH ) 6.8 Hz, 3J PtH
2
3
) 28.3 Hz, 6H, PMe), 1.55 (d, J PH ) 7.3 Hz, J PtH ) 29.3 Hz,
2
3
) 27 Hz, PMe), 16.6 (dd, J PC ) 35 and 5 Hz, J PtC ) 36 Hz,
6H, PMe), 2.20 (s, 3H, Me), 6.77 (d, J HH ) 8.3 Hz, 2H, Ar),
6.83 (d, J HH ) 8.3 Hz, 2H, Ar), 7.20-7.75 (m, 25H, Ph). 13C-
2
3
PMe), 111.7 (dd, J PC ) 126 and 20 Hz, PhCtC), 117.2 (dd,
3J PC ) 30 and 3 Hz, J PtC ) 309 Hz, PhCtC), 123.7 (q, J FC
)
{1H} NMR (CD2Cl2, 20 °C): δ 19.7 (dd, J PC ) 22 and 10 Hz,
2
3
3
2
3 Hz, SiAr), 125.8 (s, Ph), 127.9 (s, Ph), 128.9 (d, J PC ) 10
2J PtC ) 45 Hz, PMe), 20.5 (dd, J PC ) 20 and 12 Hz, J PtC ) 48
3
2
Hz, PPh), 129.1 (q, J FC ) 31 Hz, SiAr), 130.2 (s, PPh), 130.5
Hz, PMe), 21.4 (s, Me), 114.9 (d, J PC ) 50 Hz, ArCtC), 128.0
2
3
3
(s, Ph), 130.8 (s, PPh), 131.0 (d, J PC ) 10 Hz, J PtC ) 23 Hz,
(s, SiPh), 128.5 (d, J PC ) 8 Hz, PPh), 128.6 (s, Ar), 129.5 (s,
2
3
PPh), 131.3 (d, J PC ) 13 Hz, J PtC ) 21 Hz, PPh), 136.7 (dd,
SiPh, PPh and Ar), 129.8 (d, 4J PC ) 5 Hz, 3J PtC ) 26 Hz, SiPh),
1
2
3
2
J PC ) 52 and 3 Hz, PPh), 136.8 (d, J PC ) 38 Hz, PPh), 137.3
131.5 (d, J PC ) 12 Hz, J PtC ) 23 Hz, PPh), 131.7 (d, J PC
10 Hz, 3J PtC ) 23 Hz, PPh), 136.0 (s, Ar), 136.5 (s, SiPh), 137.7
(s, Ar), 141.4 (dd, J PC ) 34 and 8 Hz, PPh), 141.8 (dd, J PC
)
3
3
2
(s, J PtC ) 20 Hz, SiAr), 149.7 (d, J PC ) 5 Hz, J PtC ) 45 Hz,
SiAr). One Ph group carbon was not detected. 31P{1H} NMR
)
2
1
2
(CD2Cl2, -20 °C): δ -14.7 (d, J PP ) 23 Hz, J PtP ) 2624 Hz),
48 and 8 Hz, PPh), 154.3 (d, J PC ) 50 Hz, CtCSi). 31P{1H}

cis-Alkynyl(silyl)platinum(II) Complexes
Organometallics, Vol. 22, No. 17, 2003 3599
2
1
1
NMR (CD2Cl2, 20 °C): δ -11.9 (d, J PP ) 38 Hz, J PtP ) 3571
Ar), 140.7 (dd, J PC ) 41 and 3 Hz, PPh), 141.1 (dd, J PC ) 40
2
1
2
Hz), -12.2 (d, J PP ) 38 Hz, J PtP ) 3302 Hz).
Hz, PPh), 153.9 (dd, J PC ) 61 and 10 Hz, CtCSi). 31P{1H}
NMR (CD2Cl2, 20 °C): δ -12.6 (d, J PP ) 38 Hz, J PtP ) 3409
2 1
3d . 1H NMR (CD2Cl2, 20 °C): δ 1.27 (d, 2J PH ) 6.8 Hz, 3J PtH
2
1
2
3
) 28.8 Hz, 6H, PMe), 1.54 (d, J PH ) 7.3 Hz, J PtH ) 29.3 Hz,
Hz), -13.4 (d, J PP ) 38 Hz, J PtP ) 3520 Hz).
3
3
6H, PMe), 6.80 (d, J HH ) 8.3 Hz, 2H, Ar), 6.90 (d, J HH ) 8.3
3g. 1H NMR (CD2Cl2, 20 °C): δ 1.29 (d, 2J PH ) 5.9 Hz, 3J PtH
Hz, 2H, Ar), 7.10-7.75 (m, 25H, Ph). 13C{1H} NMR (CD2Cl2,
) 27.3 Hz, 6H, PMe), 1.57 (d, J PH ) 6.3 Hz, J PtH ) 28.8 Hz,
2
3
2
3
20 °C): δ 19.7 (dd, J PC ) 25 and 7 Hz, J PtC ) 43 Hz, PMe),
6H, PMe), 3.78 (s, 9H, OMe), 6.80 (d, J HH ) 7.3 Hz, 6H, Ar),
2
3
20.5 (dd, J PC ) 23 and 8 Hz, J PtC ) 45 Hz, PMe), 117.7 (d,
6.99 (m, 5H, Ph), 7.32 (m, 6H, Ph), 7.59 (d, J HH ) 7.3 Hz,
2J PC ) 45 Hz, ArCtC), 127.9 (s, Ar), 128.1 (s, SiPh), 128.6 (d,
3J PC ) 8 Hz, PPh), 129.6 (s, SiPh, PPh, and Ar), 130.9 (d, 4J PC
10H, Ar and Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ 19.8 (dd,
2
J PC ) 25 and 6 Hz, J PtC ) 43 Hz, PMe), 20.5 (dd, J PC ) 23
) 5 Hz, 3J PtC ) 26 Hz, SiPh), 130.9 (s, Ar), 131.4 (d, J PC ) 12
and 8 Hz, J PtC ) 43 Hz, PMe), 55.5 (s, OMe), 113.7 (s, SiAr),
2
2
Hz, 3J PtC ) 23 Hz, PPh), 131.6 (d, 2J PC ) 12 Hz, 3J PtC ) 20 Hz,
PPh), 136.4 (s, SiPh), 137.3 (s, Ar), 141.2 (dd, J PC ) 46 and 7
117.1 (d, J PC ) 44 Hz, PhCtC), 126.0 (s, Ph), 127.9 (s, Ph),
2
128.5 (d, 3J PC ) 8 Hz, PPh), 129.0 (s, PPh), 129.5 (s, Ph), 129.5
Hz, PPh), 141.5 (dd, J PC ) 45 and 7 Hz, PPh), 153.5 (d, 2J PC
)
(d, J PC ) 5 Hz, J PtC ) 26 Hz, SiAr), 131.4 (d, J PC ) 12 Hz,
2 3
4
3
2
51 Hz, CtCSi). 31P{1H} NMR (CD2Cl2, 20 °C): δ -12.7 (d, 2J PP
3J PtC ) 23 Hz, PPh), 131.6 (d, J PC ) 10 Hz, J PtC ) 20 Hz,
PPh), 137.5 (s, Ph), 137.9 (s, SiAr), 137.5 (s, Ph), 141.5 (dd,
J PC ) 34 and 6 Hz, PPh), 141.8 (dd, J PC ) 33 and 4 Hz, PPh),
1
2
1
) 37 Hz, J PtP ) 3341 Hz), -13.1 (d, J PP ) 37 Hz, J PtP
)
3555 Hz).
3e. 1H NMR (CD2Cl2, 20 °C): δ 1.26 (d, 2J PH ) 6.8 Hz, 3J PtH
153.5 (d, J PC ) 51 Hz, CtCSi), 161.0 (s, SiAr). 31P{1H} NMR
2
2
3
2
1
) 28.8 Hz, 6H, PMe), 1.53 (d, J PH ) 7.3 Hz, J PtH ) 29.8 Hz,
(CD2Cl2, 20 °C): δ -12.3 (d, J PP ) 38 Hz, J PtP ) 3343 Hz),
2 1
3
3
6H, PMe), 6.72 (d, J HH ) 8.3 Hz, 2H, Ar), 7.02 (d, J HH ) 8.3
-12.7 (d, J PP ) 38 Hz, J PtP ) 3553 Hz).
Hz, 2H, Ar), 7.10-7.75 (m, 25H, Ph). 13C{1H} NMR (CD2Cl2,
3h . 1H NMR (CD2Cl2, 20 °C): δ 1.27 (d, 2J PH ) 6.8 Hz, 3J PtH
2
2
3
20 °C): δ 19.7 (dd, J PC ) 25 and 7 Hz, J PtC ) 43 Hz, PMe),
) 28.8 Hz, 6H, PMe), 1.54 (d, J PH ) 7.3 Hz, J PtH ) 29.8 Hz,
3
2
20.5 (dd, J PC ) 23 and 8 Hz, J PtC ) 45 Hz, PMe), 118.2 (d,
6H, PMe), 2.33 (s, 9H, Me), 6.98 (m, 5H, Ph), 7.09 (d, J HH )
2J PC ) 43 Hz, ArCtC), 119.5 (s, Ar), 128.0 (s, SiPh), 128.5 (d,
7.3 Hz, 6H, Ar), 7.30 (m, 6H, Ph), 7.57 (d, 3J HH ) 7.3 Hz, 10H,
3J PC ) 8 Hz, PPh), 129.6 (s, SiPh and PPh), 130.5 (d, J PC ) 5
Ar and Ph). 13C{1H} NMR (CD2Cl2, 20 °C): δ 19.7 (dd, J PC
)
4
3
2
Hz, J PtC ) 26 Hz, SiPh), 130.8 (s, Ar), 130.9 (s, Ar), 131.4 (d,
23 and 8 Hz, J PtC ) 43 Hz, PMe), 20.6 (dd, J PC ) 22 and 10
2J PC ) 12 Hz, J PtC ) 23 Hz, PPh), 131.6 (d, J PC ) 12 Hz,
3J PtC ) 23 Hz, PPh), 136.4 (s, SiPh), 137.2 (s, Ar), 141.3 (dd,
J PC ) 40 and 8 Hz, PPh), 141.6 (dd, J PC ) 48 and 8 Hz, PPh),
Hz, J PtC ) 46 Hz, PMe), 21.8 (s, Me), 116.6 (d, J PC ) 41 Hz,
3
2
2
2
3
PhCtC), 126.0 (s, Ph), 127.8 (s, Ph), 128.5 (d, J PC ) 8 Hz,
4
PPh), 128.8 (s, SiAr), 129.5 (s, PPh and Ph), 129.5 (d, J PC
)
153.5 (d, J PC ) 51 Hz, CtCSi). 31P{1H} NMR (CD2Cl2, 20
5 Hz, J PtC ) 26 Hz, SiAr), 131.4 (d, J PC ) 10 Hz, J PtC ) 23
2 3
2
3
2
3
°C): δ -12.7 (d, 2J PP ) 38 Hz, 1J PtP ) 3342 Hz), -13.2 (d, 2J PP
Hz, PPh), 131.6 (d, J PC ) 10 Hz, J PtC ) 23 Hz, PPh), 134.3
(s, Ph), 136.5 (s, SiAr), 139.3 (s, SiAr), 141.5 (dd, J PC ) 33 and
8 Hz, PPh), 141.9 (dd, J PC ) 38 and 8 Hz, PPh), 153.7 (dd,
2J PC ) 46 and 5 Hz, CtCSi). 31P{1H} NMR (CD2Cl2, 20 °C): δ
1
) 38 Hz, J PtP ) 3552 Hz).
1
2
3
3f. H NMR (CD2Cl2, 20 °C): δ 1.28 (d, J PH ) 7.3 Hz, J PtH
2
3
) 29.3 Hz, 6H, PMe), 1.51 (d, J PH ) 7.8 Hz, J PtH ) 29.3 Hz,
3
3
2
1
2
6H, PMe), 6.87 (d, J HH ) 8.3 Hz, 2H, Ar), 7.18 (d, J HH ) 8.3
-12.4 (d, J PP ) 38 Hz, J PtP ) 3343 Hz), -12.8 (d, J PP ) 38
Hz, 2H, Ar), 7.20-7.75 (m, 25H, Ph). 13C{1H} NMR (CD2Cl2,
Hz, J PtP ) 3558 Hz).
1
2
20 °C): δ 19.5 (dd, J PC ) 27 and 3 Hz, J PtC ) 40 Hz, PMe),
2
20.4 (dd, J PC ) 27 and 5 Hz, J PtC ) 43 Hz, PMe), 108.4 (s,
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
of J apan.
2
Ar), 120.1 (s, CN), 121.7 (dd, J PC ) 53 and 8 Hz, ArCtC),
3
4
128.1 (s, SiPh), 128.6 (d, J PC ) 8 Hz, PPh), 128.8 (d, J PC ) 5
3
Hz, J PtC ) 26 Hz, SiPh), 129.7 (s, SiPh and PPh), 131.1 (d,
2J PC ) 13 Hz, J PtC ) 23 Hz, PPh), 131.5 (d, J PC ) 12 Hz,
3
2
3J PtC ) 23 Hz, PPh), 131.6 (s, Ar), 136.3 (s, SiPh), 136.9 (s,
OM0302701