Platinum(0)-enyne complexes: the platinum analogue of an intermediate in the palladium(0)-catalyzed benzannulation of conjugated enynes

Article abstract of DOI:10.1021/om000320r

Pt(0)-enyne π complexes, which could be the platinum analogues of an intermediate in the palladium(0)-catalyzed benzannulation of conjugated enynes, were synthesized, and the structure and reactivity of the complexes were investigated.

Full text of DOI:10.1021/om000320r

3740
Organometallics 2000, 19, 3740-3743
P la tin u m (0)-En yn e Com p lexes: Th e P la tin u m An a logu e
of a n In ter m ed ia te in th e P a lla d iu m (0)-Ca ta lyzed
Ben za n n u la tion of Con ju ga ted En yn es
Shinichi Saito,*,† Kazushi Tando,‡ Chizuko Kabuto,‡ and Yoshinori Yamamoto*,‡
Institute for Chemical Reaction Science and Department of Chemistry, Graduate School of
Science, Tohoku University, Sendai 980-8578, J apan
Received April 18, 2000
Summary: Pt(0)-enyne π complexes, which could be the
platinum analogues of an intermediate in the palladium-
(0)-catalyzed benzannulation of conjugated enynes, were
synthesized, and the structure and reactivity of the
complexes were investigated.
report the synthesis, structure, and reactivity of Pt(0)-
enyne complexes, which provide further information for
understanding the mechanism of the benzannulation of
conjugated enynes in the presence of Pd(0) catalyst.
Resu lts a n d Discu ssion
For the mechanistic studies of synthetically important
palladium catalyzed reactions, we frequently encounter
difficulty in isolating and identifying the palladium
intermediates, because they are highly reactive and
unstable. In such cases, the corresponding platinum
complexes are synthesized and employed for the mecha-
nistic studies, since they are in general more stable and
less reactive compared to the corresponding Pd com-
plexes. This approach has been useful in elucidating the
mechanism of the palladium-catalyzed reactions.1 Re-
cently we found a new Pd(0)-catalyzed homo-benzan-
nulation of conjugated enynes (eq 1),2 and the scope of
Conjugated enynes undergo cyclodimerization in the
presence of Pd(PPh3)4.2 Though it is clear that the
conjugate enynes are initially activated by the formation
of a complex between enynes and the Pd(0) species, it
is not clear what kind of an intermediate is formed in
the reaction and how such a complex activates the
conjugated enynes. It is less likely that the insertion of
the Pd(0) species into the acetylenic C-H bond becomes
a key step for the benzannulation, since one result of
our study indicated that the acetylenic C-H bond was
not cleaved in the benzannulation,2 and this assumption
was confirmed by the fact that some 4-substituted
enynes also cyclodimerized in the presence of Pd(0)
catalyst.4,6 We thought that the Pd(0)-enyne π complex,
which should be a highly unstable compound, might be
a possible intermediate.7 Accordingly, we synthesized
the corresponding Pt analogues and investigated their
structure and reactivity.
Conjugated enynes 1a ,b reacted with Pt(0)-ethylene
complexes 2a ,b in benzene at room temperature to give
Pt(0)-enyne complexes 3a -d in good yields (eq 2). The
structures of 3a -d were determined unambiguously by
NMR and IR analysis. 1H NMR spectrum of 1a showed
a signal integrated for one proton at 2.86 ppm (terminal
acetylene). The signal at 2.86 ppm was not observed in
this reaction has been expanded significantly by the
discovery of the cross-benzannulation reaction of enynes
with diynes.3,4 Though we initially assumed that the
mechanism of the benzannulation reaction might be
similar to that of the cyclotrimerization of alkynes, the
reaction does not proceed in the presence of CpCo(CO)2
or RhCl(PPh3)2 catalyst, which are efficient catalysts for
the cyclotrimerization of alkynes.2 In this paper we
1
the H NMR spectrum of the complex 3a , and instead a
signal integrated for one proton appeared at 6.76 ppm,
which was split into 12 peaks (4 strong peaks and 8
weak peaks). The coupling pattern could be explained
in terms of the interaction of the proton with two
nonequivalent 31P nuclei (strong signals, J (31P-H) )
22.8, 11.0 Hz) and one 195Pt nucleus (weak signals, J (195
-
† Institute for Chemical Reaction Science.
‡ Department of Chemistry, Graduate School of Science.
(1) Hartley, F. R. In Comprehensive Organometallic Chemistry;
Wilkinson, G., Stone, F. G. A., Able, E. W., Eds.; Pergamon Press:
Oxford, U.K., 1982; Vol. VI, Chapter 39, pp 471-762.
(2) Saito, S.; Salter, M. M.; Gevorgyan, V.; Tsuboya, N.; Tando, K.;
Yamamoto, Y. J . Am. Chem. Soc. 1996, 118, 3970-3971.
(3) (a) Gevorgyan, V.; Takeda, A.; Yamamoto, Y. J . Am. Chem. Soc.
1996, 118, 3970-3971. (b) Gevorgyan, V.; Takeda, A.; Homma, M.;
Sadayori, N.; Radhakrishnan, U.; Yamamoto, Y. J . Am. Chem. Soc.
1999, 121, 6391-6402.
(5) (a) Vollhardt, K. P. C. Angew. Chem., Int. Ed. Engl. 1984, 23,
539-644. (b) Neeson, S. J .; Steverson, P. J . Tetrahedron 1989, 45,
6239-6248 and references therein.
(6) (a) Saito, S.; Tsuboya, N.; Chounan, Y.; Nogami, T.; Yamamoto,
Y. Tetrahedron Lett. 1999, 40, 7529-7532. (b) Gevorgyan, V.; Tando,
K.; Uchiyama, N.; Yamamoto, Y. J . Org. Chem. 1998, 63, 7022-7025.
(7) Examples of Pd(0)-alkyne π complexes which contain internal
alkynes have been reported. See ref 1, Vol. 6, Chapter 38.5 (Maitlis,
P. M.; Espinet, P.; Russel, M. J . H.), pp 352-362. The first example of
a Pd(0)-alkyne π complex to contain a terminal alkyne (ethyne) was
recently reported by Po¨rschke et al. Pd(0)-ethyne π complexes are
unstable at room temperature. See: Krause, J .; Bonrath, W.; Po¨rschke,
K. R. Organometallics 1992, 11, 1158-1167.
(4) For reviews, see: Saito, S.; Yamamoto, Y. Chem. Rev., in press.
Gevorgyan, V.; Yamamoto, Y. J . Organomet. Chem. 1999, 576, 232-
247.
10.1021/om000320r CCC: $19.00 © 2000 American Chemical Society
Publication on Web 08/02/2000

Notes
Organometallics, Vol. 19, No. 18, 2000 3741
Ta ble 1. Selected 1H, 13C, 31P , a n d 195P t NMR Da ta for th e P t(0)-En yn e Com p lexes 3a -d a
compd
δH(tCH)
J (HP)
J (HPt)
δC(tCH)
J (CP)
J (CPt)
δP
J (PPt)
J (PP)
δPt
1a
3a
2.87
6.76
77.5
131.7
23, 11
25
67, 9
70, 6
325
274
31.6
27.1
8.2
3580
3460
3330
3190
37
30
-2601
-2734
3c
b
b
b
115.6
5.4
1b
3b
2.87
6.72
77.5
113.5
23, 11
59
63, 8
68, 6
260
274
31.7
27.1
8.2
3590
3460
3340
3190
38
30
-2582
-2726
3d
b
b
b
114.7
5.2
a
δ
b
values are given in ppm and J values in Hz. The signal overlapped with the signals of the aromatic protons.
F igu r e 1. ORTEP drawings of 3c. Ellipsoids are drawn
at the 30% probability level.
In order to examine the stability of the π-complex, we
carried out the ligand exchange experiments. Thus,
complex 3b was treated with 1 in toluene-d8, and the
reaction was monitored by NMR. The ligand exchange
reaction took place at room temperature, and the
reaction reached equilibrium in 2 h (eq 3). Since we
observed the dissociation of a small amount of the ligand
in the solutions of π-complex by NMR, we assume that
the reaction proceeds via a dissociative pathway.
Pt-H) ) 24.8 Hz). It is also noteworthy that the
signal of CtC stretching (2104 cm-1 in 1a ) was not
observed in the IR spectra of 3a . Compounds 3b -d
also showed similar spectral features (Table 1). These
results strongly indicate that the acetylenic moiety of
the enyne reacted with the Pt(0) species, and we con-
cluded that 1a ,b reacted with Pt(0)-ethylene complexes
2a ,b to give Pt(0)-enyne π-complexes 3a -d . This result
is in contrast to the results reported by Po¨rshke et al.,
who observed the formation of a mixture of Pd0{(1,2-
η2)-H2CdCHCtCH} and Pd0{(3,4-η2)-H2CdCHCtCH}
in the reaction of the Pd(0)-ethylene complex with
vinylacetylene.8 We assume that the observed difference
was caused by the steric hindrance of the 2-alkyl group
attached to the enyne.
The structure of 3c was confirmed by an X-ray
analysis (Figure 1).9 The structure of 3c was similar to
those of the well-known Pt(0)-alkyne (Pt(0)-monoyne)
complexes.10 The C(1)-C(2) distance (1.297(6) Å) is close
to the length of a standard CdC double bond.11 It is
noteworthy that the platinum atom, phosphorus atoms,
and carbon atoms of the enyne moiety lie in a plane:
the enyne moiety of 3c could further interact with
another enyne molecule without strong steric repulsion.
It is reasonable to assume that the structure of the Pd-
(0)-enyne complex, which might be formed in the initial
stage of the benzannulation reaction, is quite similar
to the structure of this complex.
We examined the reactivity of the Pt(0)-enyne com-
plexes 3 and found that the nucleophilicity of 3 was
much higher compared to that of the corresponding
conjugated enynes. Conjugated enynes only react with
strong electrophiles such as HBr and acylium ion.12 On
the other hand, complex 3b reacted with hydrazine
monohydrochloride, a weaker electrophile, as well as
(9) Crystal data for 3c: C32H32P2Pt, yellow prism, 0.10 × 0.07 ×
0.3 mm, monoclinic, P21/c, a ) 10.732(1) Å, b ) 15.706(1) Å, c ) 16.871-
(1) Å, â ) 101.081(7)°, V ) 2790.8(7) Å3, Z ) 4, Fcalcd ) 1.603 g/cm3,
2θmax ) 125.4°, Cu KR (λ ) 1.541 78 Å), ω-2θ scans, T ) 286 K. A
total of 4936 reflections ((sin θ)/λ < 0.52) was measured, of which 4292
reflections with Io > 3σ(Io) were used in the refinement. Data were
corrected for Lorentz and polarization factors, and an empirical
absorption correction using DIFABS method was applied by using the
TEXSAN program package: µ(Cu KR) ) 102.57 cm-1; minimum/
maximum transition factors 0.7498-1.0000. The structure was solved
by direct methods (SIR92). The non-hydrogen atoms were refined
anisotropically. The hydrogen atoms were included but not refined.
The number of parameters was 317. The final R factor was 0.023 (Rw
) 0.025). The final difference peaks were Fmax ) 0.89 and Fmin ) -1.09
e/Å3. See the Supporting Information for the details of the crystal-
lographic data.
(10) (a) Barlex, D. M.; Kemmitt, R. D. W.; Littlecott, G. W. J . Chem.
Soc. D 1969, 613-614. (b) Mann, B. E.; Shaw, B. L.; Tucker, N. I. J .
Chem. Soc. D 1970, 1333-1335. (c) Mann, B. E.; Shaw, B. L.; Tucker,
N. I. J . Chem. Soc. A 1971, 2667-2673. (d) Tripathy, P. B.; Roundhill,
D. M. J . Am. Chem. Soc. 1970, 92, 3825-3826. (e) Tripathy, P. B.;
Renoe, B. W.; Adzamli, K.; Roundhill, D. M. J . Am. Chem. Soc. 1971,
93, 4406-4410.
(11) Reference 1, pp 696-700.
(12) (a) Santelli-Rouvier, C.; Lefrere, S.; Mamai, M.; Santelli, M.
Tetrahedron Lett. 1995, 36, 2459-2460. (b) Taylor, D. A. Chem. Rev.
1967, 67, 317-359.
(8) Schager, F.; Bonrath, W.; Po¨rschke, K. R.; Kessler, M.; Kru¨ger,
C.; Seevogel, K. Organometallics 1997, 16, 4276-4286.

3742 Organometallics, Vol. 19, No. 18, 2000
Notes
mixture of 1a and 3b, indicating that the dissociation
of the ligand (PPh3) or the coordination of 1a with 3b
is essential for the reaction to proceed.
In summary, we isolated novel Pt(0)-enyne com-
plexes 3 and showed the high reactivity of 3. The
activation of the acetylenic moiety of the conjugated
enynes by the coordination of the Pt(0) species has been
confirmed. The corresponding Pd(0)-enyne complex
may be a possible reactive intermediate in the benzan-
nulation of conjugated enynes (eq 6).
HCl, to yield the corresponding Pt(II) σ-dienyl complex
4 (eq 4). The result can be explained by the increased
Exp er im en ta l Section
Ma ter ia ls. Enyne 1a was commercially available (Aldrich)
and was purified by distillation (bp 32 °C). Enyne 1b was
synthesized by the reaction of dilithiated 1a with 1-bromopen-
tane.16 The ethylene complexes 2a ,b were prepared by the
reduction of the corresponding dichlorides in the presence of
ethene.17 31P NMR and 195Pt NMR chemical shifts were
referenced to H2PO4/D2O and H2PtCl4/D2O, respectively.
P r a p a r a tion of P t(0)-En yn e com p lexes 3a -d . Gen er a l
P r oced u r e. To a solution of 2 (1 mmol) in dry benzene (15
mL) was added 1 (1.5-5 mmol) in dry benzene (15 mL) at room
temperature under Ar. The solution was stirred at room
temperature for 2 h. The solvent was removed by evaporation,
and the residue was treated with pentane to give a pale yellow
powder, which was separated by centrifuge separator. The Pt-
(0)-enyne complexes 3a -d partially dissociated in CDCl3, and
the spectra were complicated due to the dissociation of the
enyne and the weakness of some signals, which were coupled
with other nuclei. Some signals are therefore missing.
[CH2dCH(CH3)CtCH]P t(P P h 3)2 (3a ). Yield: 82%. Mp:
111-115 °C. 1H NMR (600 MHz, CDCl3): δ 7.4-7.1 (m, 30H),
6.76 (dd, J (31P-H) ) 23 Hz, 11.0 Hz, J (195Pt-H) ) 25 Hz, 1H),
4.71 (s, 1H), 4.37 (s, 1H), 2.03 (s, 3H). 13C NMR (150.9 MHz,
CDCl3): δ 136.9 (dd, J (31P-C) ) 41, 3 Hz, J (195Pt-C) ) 26
Hz), 136.4 (dd, J (31P-C) ) 42, 3 Hz, J (195Pt-C) ) 26 Hz), 134.1
(m), 133.8 (d, J (31P-C) ) 13 Hz, J (195Pt-C) ) 19 Hz), 131.7
(dd, J (31P-C) ) 67, 9 Hz, J (195Pt-C) ) 325 Hz), 128.9 (m),
127.6 (m), 118.1 (d, J (31P-C) ) 4 Hz, J (195Pt-C) ) 32 Hz),
114.6 (dd, J (31P-C) ) 64, 8 Hz, J (195Pt-C) ) 260 Hz), 25.1 (d,
J (31P-C) ) 6 Hz, J (195Pt-C) ) 46 Hz). 31P NMR (109 MHz,
C6D6): δ 31.6 (d, J (31P-31P) ) 37 Hz, J (195Pt-31P) ) 3580 Hz),
27.1 (d, J (31P-31P) ) 37 Hz, J (195Pt-31P) ) 3460 Hz). 195Pt
NMR (57.9 MHz, C6D6): δ -2601 (dd, J (195Pt-31P) ) 3580,
3460 Hz). IR (KBr): 3049 (m), 1684 (w), 1477 (m), 1435 (s),
1182 (w), 1094 (s), 1028 (w), 999 (w), 945 (m), 696 (s), 538 (w),
nucleophilicity of the enyne moiety on complexation.
This result also indicates that the reactivity of the
Pt(0)-enyne complex 3b is even higher than that of the
Pt(0)-monoyne complexes, since Pt(0)-monoyne com-
plexes reacted only with strong acids such as HCl and
trifluoroacetic acid to give Pt(II)-σ-alkenyl complexes,13
while it did not react with a weak acid such as hydrazine
hydrochloride.10,14 Obviously, the reactivity (nucleophi-
licity) of the π complex is enhanced to a significant
extent by attachment of an additional vinyl group. On
the basis of these results, we assume that the nucleo-
philic reactivity of the corresponding Pd(0)-enyne
complex is very high, which may play an imoprtant role
in the benzannulation of the conjugated enynes.
The importance of the π-complex as an intermediate
in the benzannulation is also shown in the reaction of
Pt(0)-enyne complex 3b with conjugated enynes. Com-
plex 3b reacted with 1b to give the 1,4-disubstituted
benzene 5 (eq 5). Though the reaction did not proceed
catalytically and the yield was low (25%), it is clear that
3b can become a partner for the cyclodimerization of
conjugated enynes.15 It is noteworthy that this reaction
was inhibited by the addition of PPh3 (1 equiv) to a
(13) (a) Chatt, J .; Rowe, G. A.; Williams, A. A. Proc. Chem. Soc. 1957,
208-209. (b) Cook, C. D.; Allen, A. D. Can. J . Chem. 1964, 42, 1603-
1068. (c) Greaves, E. O.; Lock, C. J . L.; Maitlis, P. M. Can. J . Chem.
1968, 46, 3879-3891.
(14) Pt(0)-cyclohexyne π complexes are more reactive than the Pt-
(0)-enyne π complexes we isolated. See: Bennett, M. A.; Robertson,
G. B.; Whimp, P. O.; Yoshida, T. J . Am. Chem. Soc. 1973, 95, 3028-
3030. Bennett, M. A.; Yoshida, T. J . Am. Chem. Soc. 1978, 100, 1750-
1759.
(15) Though we expected to isolate another intermediate which may
provide valuable information concerning a formal 1,3-hydride migra-
tion in the Pd(0)-catalyzed benzannulation reaction,3,4 we could not
characterize any Pt products we isolated from the reaction mixture.
When we monitored the reaction by NMR, we observed the decomposi-
tion of the Pt complex in addition to the formation of 5.
(16) Klusener, P. A. A.; Kulik, W.; Brandsma, L. J . Org. Chem. 1987,
52, 5261-5266.
(17) (a) Stang, P. J .; Song, L.; Halton, B. J . Organomet. Chem. 1990,
388, 215-220. (b) Appleton, T. G.; Bennett, M. A.; Tomkins, B. J . Chem.
Soc., Dalton Trans. 1976, 439-446.

Notes
Organometallics, Vol. 19, No. 18, 2000 3743
519 (s), 511 (w), 500 (w) cm-1. Anal. Calcd for C46H47ClP2Pt:
C, 61.92; H, 5.31; Cl, 3.97. Found: C, 62.09; H, 5.47; Cl, 3.95.
A single crystal of this compound was obtained by recrystal-
lization from hexane-CH2Cl2.
3340, 3190 Hz). IR (KBr): 3049 (w), 2926 (m), 2855 (w), 1665
(m), 1481 (w), 1435 (s), 1184 (w), 1153 (w), 1097 (s), 1028 (w),
999 (w), 966 (w), 893 (w), 831 (w), 792.7 (w), 742.5 (m), 694
(s), 664 (w), 513 (s) cm-1
.
[CH2dCH(n -C6H13)CtCH]P t(P P h 3)2 (3b). Yield: 82%.
Mp: 61-63 °C. 1H NMR (270 MHz, CDCl3): δ 7.4-7.1 (m,
30H), 6.72 (dd, J (31P-H) ) 23, 11 Hz, J (195Pt-H) ) 59 Hz),
4.66 (s, 1H), 4.37 (d, 1H, J ) 2.6 Hz), 2.28 (t, 2H, J ) 7.5 Hz),
1.52 (m, 2H), 1.23 (M, 6H), 0.88 (m, 3H). 13C NMR (67.9 MHz,
CDCl3): δ 138.9 (m), 136-138 (m), 134-135 (m), 128.9
(d, J (31P-C) ) 4 Hz), 127.6 (d, J (31P-C) ) 10 Hz), 117.1 (d,
J (31P-C) ) 4 Hz, J (195Pt-C) ) 33 Hz), 113.5 (dd, J (31P-C) )
63, 8 Hz, J (195Pt-C) ) 260 Hz), 38.9 (d, J (31P-C) ) 6 Hz,
J (195Pt-C) ) 41 Hz), 31.8, 29.1, 28.5, 22.7, 14.1. 31P NMR (109
MHz, C6D6): δ 31.7 (d, J (31P-31P) ) 38 Hz, J (195Pt-31P) ) 3590
Hz), 27.1 (d, J (31P-31P) ) 38 Hz, J (195Pt-C) ) 3460 Hz). 195Pt
NMR (57.9 MHz, C6D6): δ -2582 (dd, J (195Pt-P) ) 3590, 3460
Hz). IR (KBr): 3053 (w), 2928 (m), 2856 (w), 1684 (w), 1479
(m), 1435 (s), 1182 (w), 1094 (s), 1028 (w), 887 (w), 742 (m),
696 (s), 538 (m), 519 (s), 511 (s), 498 (w) cm-1. Anal. Calcd for
P r ep a r a tion of 4. (a) A solution of 10% (w/w) hydrogen
chloride in MeOH (46 µL, 1 equiv) was added to a solution of
3b in EtOH (2.8 mL) at 45 °C under Ar. The suspension was
stirred at 45 °C for 10 min, cooled to room temperature, and
stirred for 1 night at room temperature. The colorless powder
that formed was collected by centrifuge and washed with EtOH
to yield pure 4 (41 mg, 47%).
(b) A suspension of hydrazine hydrochloride (14 mg, 2 equiv)
in dry EtOH (1.6 mL) was added to a solution of 3b in dry
EtOH (2.4 mL) at 45 °C under Ar. The suspension was stirred
at 45 °C for 10 min, cooled to room temperature, and stirred
for 1 day at room temperature. The colorless powder that
formed was collected by centrifuge and washed with EtOH and
water and then again with EtOH. Yield: 29 mg (33%). The
same product was obtained when a mixture of hydrazine
hydrochloride (14 mg, 2 equiv) and hydrazine hydrate (50 µL)
was used instead of hydrazine hydrochloride (yield 39 mg,
44%).
C
46H46P2Pt: C, 64.55; H, 5.42. Found: C, 64.58; H, 5.75.
[CH2dCH(CH3)CtCH]P t(d p p p ) (3c). Yield: 88%. Mp:
141-150 °C. 1H NMR (270 MHz, CDCl3) δ 7.8-7.6 (m, 9H),
7.4-7.2 (m, 11H), 4.84 (s, 1H), 4.61 (s, 1H), 2.5 (m, 4H),
2.13 (s, 1H), 1.9 (m, 3H). 13C NMR (67.9 MHz, CDCl3): δ 137
(m), 133 (m), 129.3 (d, J (31P-C) ) 17 Hz), 128 (m), 118.1 (d,
J (31P-C) ) 4 Hz, J (195Pt-C) ) 33 Hz), 115.6 (dd, J (31P-C) )
70, 6 Hz, J (195Pt-C) ) 274 Hz), 28.9 (d, J (31P-C) ) 100 Hz),
28.5 (d, J (31P-C) ) 102 Hz), 24.8 (d, J (31P-C) ) 6 Hz,
J (195Pt-C) ) 45 Hz), 21.0. 31P NMR (109 MHz, C6D6): δ 8.2
(d, J (31P-31P) ) 30 Hz, J (195Pt-31P) ) 3330 Hz), 5.4 (d,
J (31P-31P) ) 30 Hz, J (195Pt-31P) ) 3190 Hz). 195Pt NMR (57.9
MHz, C6D6): δ -2734 (dd, J (195Pt-31P) ) 3330, 3190 Hz). IR
(KBr): 3053 (m), 1668 (m), 1481 (m), 1435 (s), 1184 (w), 1153
(w), 1097 (m), 1028 (w), 966 (w), 895 (w), 827 (w), 789 (w), 743
(m), 696 (s), 665 (w), 513 (s) cm-1. Anal. Calcd for C32H32P2Pt:
C, 57.06; H, 4.79. Found: C, 56.95; H, 4.76.
tr a n s-(P P h 3)2P tCl[C(dCH2)C(n -C6H13)dCH2] (4). Mp:
218-221 °C. 1H NMR (270 MHz, CDCl3): δ 7.7-7.8 (m, 12H),
7.3-7.4 (m, 18H), 6.07 (d, J ) 2.6 Hz, 1H), 5.30 (s, J (195Pt-H)
) 131 Hz, 1H), 4.78 (s, J (195Pt-H) ) 71 Hz, 1H), 4.58 (s, 1H),
0.8-1.3 (m, 13H). 13C NMR (67.9 MHz, CDCl3): δ 153.5, 147.9,
135.2 (d, J (31P-C) ) 6.1 Hz), 131.0 (t, J (31P-C) ) 27.4 Hz),
129.9, 127.6 (d, J (31P-C) ) 5.4 Hz), 117.1, 116.1, 32.5, 31.8,
29.5, 28.2, 22.6, 14.1. 31P NMR (109 MHz, CDCl3): δ 24.1 (s,
J (195Pt-31P) ) 3240 Hz). 195Pt NMR (57.9 MHz, CDCl3): δ
-6470 (d, J (195Pt-31P) ) 3240 Hz). IR (KBr): 3055 (m), 2951
(w), 2926 (m), 2866 (w), 1556 (w), 1481 (m), 1435 (s), 1188 (m),
1096 (s), 866 (m), 758 (m), 743 (s), 704 (s), 692 (s), 519 (s), 500
(s) cm-1. Anal. Calcd for C46H47ClP2Pt: C, 61.92; H, 5.31; Cl,
3.97. Found: C, 62.09; H, 5.47; Cl, 3.95.
Rea ction of 3b w ith 1b. A solution of 3b (43 mg, 50 µmol),
hexadecane (2 µL, internal standard), and 1b (44 µL, 5 equiv)
in dry toluene (0.5 mL) was heated at 100 °C under Ar. Five
hours later, a part of the solution was analyzed by GC. The
yield of 52 was determined by an NMR analysis using hexa-
decane as an internal standard.
[CH2dCH(n -C6H13)CtCH]P t(d p p p ) (3d ). Yield: 87%.
1
Yellow amorphous solid. H NMR (270 MHz, CDCl3): δ 7.7-
7.5 (m, 9H), 7.1-7.3 (m, 12H), 4.74 (s, 1H), 4.56 (d, J ) 2.6
Hz, 1H), 2.4 (m, 4H), 1.9 (m, 2H), 1.49 (m, 2H), 1.19 (m, 4H),
0.81 (m, 3H). 13C NMR (67.9 MHz, CDCl3): δ 140.5 (m), 137
(m), 133 (m), 129.3 (d, J (31P-C) ) 16 Hz), 128 (m), 117.1 (d,
J (31P-C) ) 6 Hz, J (195Pt-C) ) 33 Hz), 114.7 (dd, J (31P-C) )
68, 6 Hz, J (195Pt-C) ) 274 Hz), 38.7 (d, J (31P-C) ) 6 Hz,
J (195Pt-C) ) 40 Hz), 31.8, 29.2, 28.9 (d, J (31P-C) ) 104 Hz),
28.7, 28.5 (d, J (31P-C) ) 106 Hz), 22.7, 20.9, 14.1. 31P NMR
(109 MHz, C6D6): δ 8.2 (d, J (31P-31P) ) 30 Hz, J (195Pt-31P) )
3340 Hz), 5.2 (d, J (31P-31P) ) 30 Hz, J (195Pt-31P) ) 3190 Hz).
195Pt NMR (57.9 MHz, C6D6): δ -2726 (dd, J (195Pt-31P) )
Su p p or tin g In for m a tion Ava ila ble: Text and tables
giving details of the X-ray crystallographic analysis of 3c and
figures giving 1H and 13C NMR spectra of 3a -d . This material
is available free of charge via the Internet at http://pubs.acs.org.
OM000320R