Study on the anti-sulfur-poisoning characteristics of platinum-acetylide- phosphine complexes as catalysts for hydrosilylation reactions

Article abstract of DOI:10.1002/aoc.3149

A series of platinum-acetylide-phosphine complexes were synthesized and their anti-sulfur-poisoning characteristics investigated. In comparison with Speier's and Karstedt's catalysts, the platinum-acetylide-phosphine complexes exhibited both higher catalytic activity and selectivity for the β-adduct for the hydrosilylation reactions under the same conditions. Furthermore, the complexes also exhibited a strong ability to resist to sulfur-poisoning. This indicated that the alkyne ligands containing the silyl group had a strong impact on the hydrosilylation reaction. Copyright

Full text of DOI:10.1002/aoc.3149

Full Paper
Received: 13 November 2013
Revised: 6 February 2014
Accepted: 25 February 2014
Published online in Wiley Online Library: 22 April 2014
(wileyonlinelibrary.com) DOI 10.1002/aoc.3149
Study on the anti-sulfur-poisoning characteristics
of platinum–acetylide–phosphine complexes as
catalysts for hydrosilylation reactions
Jiayun Li, Congbai Niu, Jiajian Peng*, Yuan Deng, Guodong Zhang, Ying Bai,
Chao Ma, Wenjun Xiao and Guoqiao Lai
A series of platinum–acetylide–phosphine complexes were synthesized and their anti-sulfur-poisoning characteristics
investigated. In comparison with Speier’s and Karstedt’s catalysts, the platinum–acetylide–phosphine complexes
exhibited both higher catalytic activity and selectivity for the β-adduct for the hydrosilylation reactions under the same
conditions. Furthermore, the complexes also exhibited a strong ability to resist to sulfur-poisoning. This indicated that
the alkyne ligands containing the silyl group had a strong impact on the hydrosilylation reaction. Copyright © 2014
John Wiley & Sons, Ltd.
Additional supporting information may be found in the online version of this article at the publisher’s web-site.
Keywords: platinum–acetylide–phosphine complexes; anti-sulfur poisoning; hydrosilylation
hydrosilylation of styrene with triethoxysilane as a model reaction
Introduction
(Scheme 1).[15–19]
A number of organosilicon monomers and polymers containing
functional groups have been synthesized via hydrosilylation
reactions. Hydrosilylation of C¼C is one of the most important
Si―C bond formation reactions and commercial reactions.
Various transition metal catalysts have been successively
researched and applied to the hydrosilylation reaction. In 1947,
H2PtCl6.6H2O/isopropanol (Speier’s catalyst) was first found to
be effective in the hydrosilylation of alkenes and alkynes with
silanes.[1–3] Thereafter, Pt(0)–divinyltetramethyldisiloxane com-
plex (Karstedt’s catalyst), by virtue of its higher activity, gradually
replaced Speier’s catalyst.[4–8] For hydrosilylation of alkenes and
alkynes with silanes Karstedt’s catalyst is the most active catalyst
in current use. However, sulfur compounds are still a poison for
the platinum catalyst, and significantly decreased the catalytic
activity of platinum catalysts for hydrosilylation processes.
Usually, low catalytic activity of Karstedt’s catalyst or Speier’s
catalyst was observed, owing to the raw material with trace
amounts of sulfur, nitrogen and other elements in practical appli-
cation, in particular sulfur element. Several of compounds, e.g.
aluminum acetylacetonate, iron chelate complexes, as well as
polyhydrosiloxane coat, have been reported to serve as anti-
sulfur-poisoning agents of Pt catalyst.[9,10] Hence the develop-
ment of new catalysts for the hydrosilylation reaction along with
a strong ability to resist sulfur poisoning is an ongoing challenge.
For example, trans-Pt(PPh3)2[CꢀCC6H6(OH)]2 has shown stable
and high activity for addition-cross-linking curable; however, the re-
action time was too long and still not satisfactory.[11–14] On the
other hand, Soeda[11] found that trans-Pt(PPh3)2[CꢀCC6H5]2
showed catalytic activity of hydrosilylation in the presence of a
small amount of poisonous sulfur. In this paper, a series of novel
platinum–acetylide–phosphine complexes was synthesized, and
tolerance to sulfur poisoning was investigated by catalytic
Experimental
General Information
All chemicals were purchased from Aldrich and were used as
received. All synthesis procedures were carried out under argon
using standard Schlenk and vacuum-line techniques. Solvents for
synthesis were dried and degassed by standard methods before use.
Gas chromatography: Trace DSQ GC column DB-5 30 m × 2.5
mm × 0.25 mm, split 50:1, flow 1 mL minꢁ1 constant flow, inlet
temperature 260°C, column temperature 50°C (hold 1 min) then
15°C minꢁ1 up to 260°C (hold 10 min).
1H, 13C, 29Si and 31P NMR spectra were measured using a
Bruker Avance 400 MHz spectrometer operating at 400.13,
100.62, 79.49 and 161.97 MHz, respectively, using TMS as an
internal standard and CDCl3 as solvent. 31P NMR chemical shifts
are relative to 85% H3PO4 external standard.
Elemental analyses were performed on a Vario EL-III elemental
analyzer, and IR spectra were recorded on a Nicolet 5700
instrument. GC-MS was tested with a Trace DSQ GC-MS column.
Speier’s catalyst and Karstedt’s catalyst were prepared by
literature methods.[20]
*
Correspondence to: Jiajian Peng, Key Laboratory of Organosilicon Chemis-
try and Material Technology of Ministry of Education, Hangzhou Normal
University, Hangzhou 310012, People’s Republic of China. E-mail: jjpeng@
hznu.edu.cn
Key Laboratory of Organosilicon Chemistry and Material Technology of
Ministry of Education, Hangzhou Normal University, Hangzhou 310012, People’s
Republic of China
Appl. Organometal. Chem. 2014, 28, 454–460
Copyright © 2014 John Wiley & Sons, Ltd.

Platinum–acetylide–phosphine as catalyst for hydrosilylation reactions
13C NMR, 31P NMR and IR) and elemental analy-
sis data of the prepared compound 5a were in
agreement with the assigned structures and
with those found in the literature.[21]
Synthesis of trans-Pt(PPh3)2(―CꢀC―SiR3)2 and
trans-Pt[PPh2Si(CH3)3] (―CꢀC―SiR3)2, R = ―CH3,
2
―C2H5, ―CH(CH3)2, ―Ph
Synthesis of trans-Pt(PPh3)2(―CꢀC―SiR3)2 R = ―CH3,
―C2H5, ―CH(CH3)2, ―Ph. A mixture of trans-Pt
(PPh3)2Cl2 (1 mmol) and CHꢀCSiR3 (2.2 mmol)
in diethylamine/THF ( 10 mmol/20 ml) was
allowed to react in the presence of CuI (5 mg)
at 80°C for 6 h. Evaporation of the solvent
Scheme 1. Hydrosilylation of alkenes with triethoxysilane or triethylsilane. R1: OEt, Et.
and purification of the residue by chromatography on alumina
eluting with hexane–benzene (1:1) afforded the product.
Recrystallization from n-hexane gave product trans-Pt(PPh3)2
(―CꢀC―SiR3)2.
General Procedure for Synthesis of Platinum–Acetylide–
Phosphine Complexes (Scheme 2)
Synthesis of trans-Pt(PPh3)2Cl2 , trans-Pt[PPh2Si(CH3)3]2Cl2 and
trans-Pt(PPh3)2(―CꢀCPh)2
Complex 1b: trans-Pt(PPh3)2 [CHꢀCSi(CH3)3]2 (flavescent solid, yield
trans-Pt(PPh3)2Cl2 (1a) was prepared by literature methods.[20]
trans-Pt[PPh2Si(CH3)3]2Cl2 (2a): an excess of PPh2Si(CH3)3
(2.5mmol) was added to a boiling solution of CH3OH (60 ml).
K2PtCl4 (1mmol) was added in water and the mixture was stirred
at 60°C for 2 h. The solid was obtained by filtration and washed with
water, CH3OH and ethyl ether, respectively. The product was
dried in vacuo to obtain 2a in 87% yield (flavescent solid).
1H NMR δ (ppm): 0.33 (s, 18H, Si(CH3)3), 7.10–7.58 (m, 20H,
PPh2).13C NMR δ (ppm): 0.10 (Si(CH3)3), 127.41 (t, JC―P = 6 Hz, meta),
129.40 (m, ortho), 132.10 (para), 135.13 (m, ipso) (PPh3). 29Si NMR
δ (ppm): 6.70. 31P NMR δ (ppm): 31.60 (JP―Pt = 2618 Hz). Anal.
Calcd for 2a (C30H38Cl2P2PtSi2): C, 46.03; H, 4.89. Found: C,
46.01; H, 4.88.
trans-Pt(PPh3)2(―CꢀCPh)2 (3a) (flavescent solid, 74 % yield)
was prepared by literature methods. The spectroscopic data
(1H NMR, 13C NMR, 31P NMR and IR) and elemental analysis data
of the prepared compound 3a were in agreement with the
assigned structures and with those found in the literature
(Fig. 1).[21]
1
91%), IR (KBr): 2087 cmꢁ1 (νCꢀC). H NMR δ (ppm): 0.02 (s, 18H,
Si(CH3)3), 7.35–7.58 (m, 30H, PPh2).13C NMR δ (ppm): ꢁ0.90
(Si(CH3)3), 104.71 (C―CꢀC), 115.32 (t, J = 16.1 Hz, Pt―CꢀC),
127.61 (t, JC―P = 6 Hz, meta), 129.10 (m, ortho), 133.81 (para),
135.90 (m, ipso) (PPh3). 29Si NMR δ (ppm): 14.21. 31P NMR δ
(ppm): 18.60 (JP―Pt = 1837 Hz). Anal. Calcd for 1b (C46H48P2Pt Si2):
C, 60.44; H, 5.29. Found: C, 60.42; H, 5.28.
Complex 2b: trans-Pt(PPh3)2[CHꢀCSi(CH2CH3)3]2 (flavescent solid,
yield 84%), IR (KBr): 2094 cmꢁ1 (νCꢀC).1H NMR δ (ppm): 0.64
(q, J = 12 Hz, 12H, Si(CH2CH3)3), 1.04 (t, J = 12 Hz, 18H, Si(CH2CH3)3),
7.30–7.72 (m, 30H, PPh2). 13C NMR δ (ppm): 4.50 (Si (CH2CH3)3),
7.51 (Si (CH2CH3)3), 105.20 (C―CꢀC), 121.51 (t, J=16.1Hz, Pt―CꢀC),
127.92 (t, JC―P = 6 Hz, meta), 131.94 (m, ortho), 132.10 (para), 135.23
(m, ipso) (PPh3). 29Si NMR δ (ppm): 16.10. 31P NMR δ (ppm): 19.00
(JP―Pt = 1858 Hz). Anal. Calcd for 2b (C52H60P2Pt Si2): C, 62.57; H,
6.06. Found: C, 62.55; H, 6.05.
Complex 3b: spectroscopic data (1H NMR, 13C NMR, 29Si NMR, 31
P
NMR and IR) and elemental analysis data of the prepared com-
pound 3b were in agreement with the assigned structures and with
those found in the literature.[21] Complex 4b: trans-Pt(PPh3)2
(CHꢀCSiPh3)2 (flavescent solid, yield 79%), IR (KBr): 2108 cmꢁ1
(νCꢀC).1H NMR δ (ppm): 6.98–7.71 (m, 60H, PPh2, Si (Ph)3). 13C NMR
δ (ppm): 102.11 (C―CꢀC), 112.51 (t, J=15Hz, Pt―CꢀC), 127.72
(t, JC―P =6Hz, meta) , 131.92 (m, ortho), 134.71 (para), 135.52
(m, ipso) (PPh3), 129.73 (t, J = 6 Hz, meta), 132.14 (m, ortho), 134.91
(para), 136.11 (m, ipso) (SiPh3). 29Si NMR δ (ppm): ꢁ15.20. 31P NMR
δ (ppm): 19.20 (JP―Pt =1818Hz). Anal. Calcd for 4b (C76H60P2Pt Si2):
C, 70.95; H, 4.70. Found: C, 70.97; H, 4.70.
trans-Pt(PPh3)2[―CꢀCC(CH3)2OH]2 (4a) (yield 89%) was
prepared by literature methods. Spectroscopic data (1H NMR,
13C NMR, 31P NMR and IR) and elemental analysis data of the
prepared compound 4a were in agreement with the assigned
structures and with those found in the literature.[21]
trans-Pt(PPh3)2[―CꢀC(C6H10)OH]2 (5a) (yield 91%) was
prepared by literature methods. Spectroscopic data (1H NMR,
Synthesis of trans-Pt[PPh2Si(CH3)3] 2(ꢀC―C―SiR3)2, R = ―CH3, ―C2H5,
―CH(CH3)2, ―Ph.
A mixture of trans-Pt[PPh2Si(CH3)3] 2Cl2
(1 mmol) and CHꢀCSiR3 (R = ―CH3, ―C2H5, ―CH(CH3)2 , ―Ph)
(2.2 mmol) in diethylamine/THF was allowed to react in the
presence of CuI (5mg) at 80°C for 6 h. Evaporation of the solvent
and purification of the residue by chromatography on alumina
eluting with hexane/benzene (1:1) afforded the product.
Recrystallization from n-hexane gave product trans-Pt[PPh2Si(CH3)3]
2(―CꢀC―SiR3)2.
Complex 5b: trans-Pt[PPh2Si(CH3)3]2[CHꢀCSi(CH3)3]2 (flavescent
solid, yield 84%), IR (KBr): 2033 cmꢁ1 (νCꢀC). 1H NMR δ (ppm): 0.02
(s, 18H, Si(CH3)3), 0.12 (s, 18H, Si(CH3)3), 7.10–7.76 (m, 20H, PPh2).13C
NMR δ (ppm): 1.40 (Si(CH3)3), 1.90 (Si(CH3)3), 102.91 (C―CꢀC),
Scheme 2. Synthesis of trans-Pt(PPh3)2(―CꢀC―SiR3)2 and trans-Pt[PPh2Si
(CH3)3] 2(―CꢀC-SiR3)2.
Appl. Organometal. Chem. 2014, 28, 454–460
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

J. Li et al.
with constant stirring for 2 h. At the end of the reaction, the conver-
sion of alkene and the selectivity were determined by GC. All data
in the tables are the average values of three experiments.
Hydrosilylation of styrene with triethoxysilane: β-Adduct [triethoxy
(phenylethyl)silane] and α-adduct [triethoxy(1-phenylethyl)silane].
Spectroscopic data (1H NMR) and elemental analysis data of the
prepared compounds were in agreement with the assigned struc-
tures and with those found in the literature.[22]
Hydrosilylation of o-methylstyrene with triethoxysilane
β-Adduct [triethoxy(o-methylphenylethyl)silane]: 1H NMR δ (ppm):
1.05 (t, J = 8.5 Hz, 2H, Si―CH2), 1.37 (t, J = 7.0 Hz, 9H, CH3), 2.42
(s, 3H, CH3), 2.77 (t, J = 8.5Hz, 2H, CH2), 3.87 (q, J = 7.0 Hz, 6H,
O―CH2), 7.08–7.35 (m, 4H, Ph). 13C NMR δ (ppm): 142.77 (ipso,
CH2CH2Ph), 135.32 (ipso), 130.11 (ortho), 128.06 (meta), 126.11
(meta), 125.82 (para) (CH3Ph), 58.40 (OCH2CH3), 26.34 (CH2CH2Ph),
19.07 (CH3Ph), 18.36 (OCH2CH3), 11.53 (SiCH2). 29Si NMR δ (ppm):
ꢁ46.09. MS (EI) m/z (%): 283 (M+, 16), 282 (100). Anal. Calcd for
[triethoxy(o-methylphenylethyl)silane] (C15H26O3Si): C 63.78; H
9.28; O 16.99. Found: C 63.75; H 9.27; O 17.00. IR (KBr): 449, 632,
Figure 1. Molecular structure of 3a drawn with 30% probability dis-
placement ellipsoids.
764, 784, 969, 1015, 1415, 2766, 2930 cmꢁ1
.
118.62 (t, J = 15 Hz, Pt―CꢀC), 128.40 (t, JC―P = 8 Hz, meta), 129.81
(m, ortho), 131.80 (para), 132.01 (m, ipso) (PPh3). 29Si NMR δ (ppm):
6.90, 14.21. 31P NMR δ (ppm): 31.60 (JP―Pt = 2898 Hz). Anal. Calcd
for 5b (C40H56P2Pt Si4): C, 53.01; H, 6.23. Found: C 52.99; H 6.21.
Complex 6b: trans-Pt[PPh2Si(CH3)3]2[CHꢀCSi(CH2CH3)3]2 (flavescent
Hydrosilylation of m-methylstyrene with triethoxysilane
β-Adduct [triethoxy(m-methylphenylethyl)silane]: 1H NMR δ (ppm):
1.10 (t, J = 8.5 Hz, 2H, Si―CH2), 1.36 (t, J = 7.0 Hz, 9H, CH3), 2.43
(s, 3H, CH3), 2.79 (t, J = 8.5Hz, 2H, CH2), 3.94 (q, J = 7.0 Hz, 6H,
O―CH2), 7.15–7.22 (m, 4H, Ph). 13C NMR δ (ppm): 144.60 (ipso,
CH2CH2Ph), 137.59 (ipso), 128.65 (ortho), 128.27 (meta), 126.38
(ortho), 124.91 (para) (CH3Ph), 58.33 (OCH2CH3), 28.99 (CH2CH2Ph),
21.32 (CH3Ph), 18.34 (OCH2CH3), 12.85 (SiCH2). 29Si NMR δ (ppm):
ꢁ46.24. MS (EI) m/z (%): 283 (M+, 15), 282 (100). Anal. Calcd for
[triethoxy(m-methylphenylethyl)silane] (C15H26O3Si): C 63.78; H
9.28; O 16.99. Found: C 63.77; H 9.28; O 16.98. IR (KBr): 457, 637,
1
solid, yield 81%), IR (KBr): 2073 cmꢁ1 (νCꢀC). H NMR δ (ppm): 0.01
(s, 18H, Si(CH3)3), 0.54 (q, J = 12 Hz, 12H, Si(CH2CH3)3), 0.93
(t, J = 12 Hz, 18H, Si(CH2CH3)3), 6.90–7.73 (m, 20H, PPh2).13
C
NMR δ (ppm): 0.10 (Si(CH3)3), 4.60 (Si (CH2CH3)3), 7.51 (Si (CH2CH3)3),
110.31 (C―CꢀC), 125.22 (t, J = 15 Hz, Pt―CꢀC), 127.31 (t, JC―P
=
8 Hz, meta), 129.5 (m, ortho), 131.13 (para), 132.11 (m, ipso)
(PPh3). 29Si NMR δ (ppm): 7.10, 16.50. 31P NMR (CDCl3, 162 MHz) δ
(ppm): 31.60 (JP―Pt = 2818 Hz). Anal. Calcd for 6b (C46H68P2Pt Si4):
C 55.78; H 6.92. Found: C 55.80; H 6.92.
715, 743, 767, 971, 1017, 1417, 2810, 3042 cmꢁ1
.
Complex 7b: trans-Pt[PPh2Si(CH3)3]2[CHꢀCSi(CH(CH3)2)3]2 (flavescent
solid, yield 83%), IR (KBr): 2068 cmꢁ1 (νCꢀC). 1H NMR δ (ppm): 0.01
(s, 18H, Si(CH3)3), 0.35 (septet, J = 7.3Hz, 6H, CH(CH3)2), 0.61
(d, J = 7.3Hz, 36H, CH(CH3)2), 7.08–7.81 (m, 20H, PPh2). 13C NMR δ
(ppm): ꢁ0.03 (Si(CH3)3), 10.90 (CH(CH3)2), 18.41 (CH(CH3)2), 94.92
(C―CꢀC), 124.13 (t, J = 15 Hz, Pt―CꢀC), 127.31 (t, JC―P = 8 Hz,
meta), 129.92 (m, ortho), 131.84 (para), 132.41 (m, ipso) (PPh3). 29Si
NMR δ (ppm): 6.80, 18.10. 31P NMR δ (ppm): 30.60 (JP―Pt = 2834 Hz).
Anal. Calcd for 7b (C52H80P2Pt Si4): C, 58.12; H, 7.50. Found: C
58.10; H 7.51.
Complex 8b: trans-Pt[PPh2Si(CH3)3]2(CHꢀCSiPh3)2 (flavescent solid,
yield 73%), IR (KBr): 2127 cmꢁ1 (νCꢀC). 1H NMR δ (ppm): 0.08 (s, 18H,
Si(CH3)3), 6.90–8.02 (m, 50H, PPh2, Si (Ph)3).13C NMR δ (ppm): 1.00
(Si(CH3)3), 102.51 (C―CꢀC), 118.82 (t, J = 15 Hz, Pt―CꢀC), 127.81
(t, JC―P = 6 Hz, meta) , 130.10 (m, ortho), 132.01 (para), 134.73
(m, ipso) (PPh3), 129.11 (t, J = 6 Hz, meta), 131.31 (m, ortho), 132.22
(para), 134.93 (m, ipso) (SiPh3). 29Si NMR δ (ppm): 7.10, ꢁ15.60.
31P NMR δ (ppm): 31.80 (JP―Pt = 2818 Hz). Anal. Calcd for 8b
(C70H68P2Pt Si4): C 65.75; H 5.36. Found: C 65.73; H 5.37.
Hydrosilylation of p-methylstyrene with triethoxysilane
β-Adduct [triethoxy(p-methylphenylethyl)silane]: 1H NMR δ (ppm):
1.03 (t, J = 8.5 Hz, 2H, Si―CH2), 1.28 (t, J = 7.0 Hz, 9H, CH3), 2.31
(s, 3H, CH3), 2.70 (t, J= 8.5 Hz, 2H, CH2), 3.87 (q, J= 7.0 Hz, 6H, O―CH2),
7.07–7.11 (m, 4H, Ph). 13C NMR δ (ppm): 141.66 (ipso, CH2CH2Ph),
134.97 (ipso), 129.02 (ortho), 127.82 (meta) (Ph), 58.80 (OCH2CH3),
28.53 (CH2CH2Ph), 20.96 (CH3Ph), 18.12 (OCH2CH3), 12.08 (SiCH2). 29Si
NMR δ (ppm): ꢁ45.96. MS (EI) m/z (%): 283 (M+, 16), 282 (100).
Anal. Calcd for [triethoxy(p-methylphenethyl)silane] (C15H26O3Si):
C 63.78; H 9.28; O 16.99. Found: C 63.79; H 9.27; O 16.99. IR
(KBr): 453, 631, 767, 857, 971, 1019, 1411, 2768, 3231 cmꢁ1
.
Hydrosilylation of p-methoxystyrene with triethoxysilane
β-Adduct [triethoxy(p-methoxyphenylethyl)silane]: 1H NMR δ (ppm):
1.02 (t, J= 8.5Hz, 2H, Si―CH2), 1.24 (t, J= 7.0Hz, 9H, CH3), 2.70
(t, J= 8.5Hz, 2H, CH2), 3.70 (s, 3H, O―CH3), 3.79 (q, J= 7.0 Hz, 6H,
O―CH2), 6.95–7.26 (m, 4H, Ph). 13C NMR δ (ppm): 157.79
(ipso, CH2CH2Ph), 136.57 (ipso), 128.58 (meta), 113.65 (ortho)
(CH3OPh), 58.21 (OCH2CH3), 54.84(OCH3), 28.05 (CH2CH2Ph), 18.23
(OCH2CH3), 12.92 (SiCH2). 29Si NMR (CDCl3) δ (ppm): ꢁ46.29. MS (EI)
m/z (%): 299 (M+, 22), 298 (100). Anal. Calcd for [triethoxy(p-
methoxyphenylethyl)silane] (C15H26O4Si): C 60.37; H 8.78; O 21.44.
Found: C 60.35; H 8.78; O 21.45. IR (KBr): 467, 637, 781, 857, 964,
Hydrosilylation
Typical hydrosilylation reaction procedures were as follows. A given
amount of the alkene and silane was added to a 10 ml round-bot-
tomed flask equipped with a magnetic stirrer and a given amount
of catalyst was added. This mixture was heated to the appropriate
temperature and the hydrosilylation reaction was allowed to proceed
1085, 1483, 2884, 3222 cmꢁ1
.
wileyonlinelibrary.com/journal/aoc
Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 454–460

Platinum–acetylide–phosphine as catalyst for hydrosilylation reactions
Hydrosilylation of p-fluorostyrene with triethoxysilane
Table 1. Crystal data, data collection, and structure refinement details
β-Adduct [triethoxy(p-fluorophenylethyl)silane]: 1H NMR δ (ppm):
1.01 (t, J= 8.5 Hz, 2H, Si―CH2), 1.21 (t, J = 7.0 Hz, 9H, CH3), 2.70
(t, J = 8.5 Hz, 2H, CH2), 3.78 (q, J = 7.0 Hz, 6H, O―CH2), 6.84–7.24
3a·2CHCl3
Empirical formula
Formula weight
Crystal system
space group
Unit cell dimensions
a (Å)
C54H42Cl6P2Pt
1160.61
Triclinic
P-1
1
(m, 4H, Ph). 13C NMR δ (ppm): 162.36 (s, JC―F = 241 Hz, para),
4
3
139.65 (d, JC―F = 3.0 Hz, ipso), 129.04 (d, JC―F = 6.0 Hz, ortho),
2
114.72 (d, JC―F = 21 Hz, meta) (FPh), 58.29 (OCH2CH3), 28.15
(CH2CH2Ph), 18.17 (OCH2CH3), 12.76 (SiCH2). 29Si NMR δ (ppm):
ꢁ46.55. MS (EI) m/z (%): 287 (M+, 20), 286 (100). Anal. Calcd for
[triethoxy(p-fluorophenylethyl)silane] (C14H23FO3Si): C 58.71; H
8.09; O 16.76. Found: C 58.83; H 8.08; O 16.77. IR (KBr): 449, 467,
8.2677(5)
b (Å)
12.0185(7)
c (Å)
12.9515(8)
α (°)
β (°)
γ (°)
83.0290(10)
638, 783, 859, 974, 1089, 1485, 2993, 3429 cmꢁ1
.
84.5930(10)
Hydrosilylation of 1-hexene with triethoxysilane: β-Adduct
[triethoxy(hexyl)silane]. Spectroscopic data (1H NMR 13C NMR
and 29Si NMR) and elemental analysis data of the prepared
compound were in agreement with the assigned structures and
with those found in the literature.[22]
Hydrosilylation of 1-dodecene with triethoxysilane: β-Adduct
[triethoxy(dodecyl)silane] . Spectroscopic data (1H NMR 13C NMR
and 29Si NMR) and elemental analysis data of the prepared
compound were in agreement with the assigned structures and
with those found in the literature.[22]
82.4900(10)
Volume (Å3)
Z, calculated density
1262.44(13)
1, 1.527 Mg mꢁ3
3.195
Abs. coeff. (mmꢁ1
)
F(000)
576
Reflections collected/unique
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]
R indices (all data)
14 845/4368 [R(int) = 0.0206]
1.123
R1 = 0.0253, wR2 = 0.0783
R1 = 0.0321, wR2 = 0.1135
Hydrosilylation reaction of styrene with triethylsilane: β-Adduct
[triethyl(phenylethyl)silane]. Spectroscopic data (1H NMR 13C
NMR and 29Si NMR) and elemental analysis data of the prepared
compound were in agreement with the assigned structures and
with those found in the literature.[22]
prepared in high yields.[25–29] In this paper, trans-platinum
acetylide complexes (1b–4b) were synthesized as shown in
Scheme 2. trans-Pt[PPh2Si(CH3)3]2Cl2 2a was synthesized from
K2PtCl4 and PPh2Si(CH3)3. A series of novel platinum–acetylide–
phosphine complexes 5b–8b was synthesized. The appropriate al-
kyne-containing silyl group was added to a degassing and a
dehydrating solution of trans-Pt[PPh2Si(CH3)3]2Cl2 in Et2NH–THF. A
catalytic amount of CuI was added and the mixture was stirred at
80°C for 6 h. After work-up, the trans-(PPh3)2Pt(CꢀCSiR3)2 com-
plexes, 5b–8b, were all isolated as stable solids in good yield. Infra-
red spectroscopy is a useful tool to confirm the chemical
modifications proposed. The bands present in the diffuse-reflection
infrared Fourier transform spectra of 1b at 2087 cmꢁ1, 2b at
2094 cmꢁ1 … and 8b at 2127 cmꢁ1 are assigned to the presence
of carbon–carbon triple bonds.[30–33] The structure of complex
3a was determined by X-ray analysis (Figs. 1 and 2) and all of
the platinum acetylide complexes were also characterized by
Study of the Anti-Sulfur-Poisoning Characteristics of the
Synthesized Platinum–Acetylide–Phosphine Complexes
A given amount of the alkene, silane and benzothiazole as sulfur
poisoning was added to a 10 ml round-bottomed flask equipped
with a magnetic stirrer and a given amount of catalyst was then
added. This mixture was heated to the appropriate temperature
and the hydrosilylation reaction was allowed to proceed with
constant stirring for 2 h. At the end of the reaction, the conversion
of alkene and the selectivity was determined by GC.
X-Ray Structure Determinations of Complexes 3a
Colorless single crystals of the compounds (dimensions, 3a:
0.35 × 0.31 × 0.30 mm) were produced by slow evaporation of
the solvents from solutions in hexane–dichloromethane mixtures
at 25°C. Diffraction data were collected at room temperature by
the φ-scan and ω-scan technique on a Smart Apex Duo diffrac-
tometer with graphite-monochromated Mo-Kα radiation
(λ = 0.71073Å). The structures were solved by direct methods
(SHELXTL-PLUS)[23] and subsequently difference Fourier synthesis,
and were then refined by full-matrix least squares on F2
(SHELXL-97).[24] Absorption correction types were carried out
using a multi-scan method. All non-hydrogen atoms were re-
fined anisotropically, while hydrogen atoms were placed in geo-
metrically idealized positions. Crystal data and details of the
structures are given in Table 1.
Results and Discussion
Platinum acetylide complexes such as 3a are readily prepared
in high yields from the reaction of phenylacetylene with
trans-(PPh3P)2PtCl2.[25–29] Complexes 4a and 5a are also
Figure 2. Molecular structure of 3b drawn with 30% probability dis-
placement ellipsoids.
Appl. Organometal. Chem. 2014, 28, 454–460
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

J. Li et al.
NMR spectroscopy. All of the prepared complexes showed 1H
NMR, 13C NMR, 31P NMR and 29Si NMR spectroscopic data in
accordance with the proposed structures. Elemental analysis
data and theoretical values for the platinum complexes
1a–8b were also found to be in accordance. These results
were obtained after the synthesis of a series of platinum
acetylide complexes.
Table 2. Results of the hydrosilylation reaction of styrene with
triethoxysilane
Selectivity (%)
Entry
Catalyst
(mol %)
S poison Conversion
β
α
By-
(mol %)
(%)
producta
1
Karstedt’s 0.025
Karstedt’s 0.025
Karstedt’s 0.05
Karstedt’s 0.05
Speier 0.05
Speier 0.05
Pd(PPh3)2Cl2
1a 0.05
—
0.02
—
99.8
60.1 38.7
1.2
—
The platinum complexes prepared were tested in the
hydrosilylation reaction of styrene with triethoxysilane as model
reaction, and the results are listed in Table 2. At the same time,
benzothiazole was added to the reaction mixtures to check the
ability to resist sulfur poisoning of these prepared platinum
acetylide complexes. The hydrosilylation reaction was
performed by Speier’s catalyst or Karstedt’s catalyst with no
sulfur compound, and showed a high level of conversion, but
only a low level of β-adduct selectivity was obtained. The
hydrosilylation reaction was examined using trans-Pt(PPh3)2Cl2
or trans-Pt[PPh2Si(CH3)3] 2Cl2 as a catalyst under similar
conditions; this showed a high level of conversion and β-adduct
selectivity was obtained. No β-adduct was detected for Pd
(PPh3)2Cl2 catalyst. The role of PPh3 or (CH3)3SiPPh2 ligand
was thought to improve the selectivity of the β-adduct.[34] How-
ever, Speier’s catalyst or Karstedt’s catalyst was inactive under
hydrosilylation reaction conditions when a small amount of
benzothiazole was added. A similar situation occurred when
trans-Pt(PPh3)2Cl2 or trans-Pt[PPh2Si(CH3)3]2Cl2catalyst was used
(Table 2, entries 1–11). Although a low level of catalytic
activity and selectivity of β-adduct was observed in the
hydrosilylation reaction of the styrene with triethoxysilane cat-
alyzed with trans-Pt(PPh3)2(―CꢀCPh)2 (3a), 3a exhibited tolerance
to sulfur poisoning. trans-Pt(PPh3)2[―CꢀCC(CH3)2OH]2 (4a) and
trans-Pt(PPh3)2[―CꢀC(C6H10)OH]2 (5a) showed the same results
as trans-Pt(PPh3)2(―CꢀCPh)2 (3a).
2
—
99.9
—
—
—
3
59.9 38.8
1.3
—
4
0.02
—
—
—
5
85.7
—
65.6 34.1
0.3
—
6
0.02
—
—
—
—
—
7
4.74%
100
3.4
—
8
—
95.4
—
82.9 13.7
9
1a 0.05
0.02
—
—
—
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
2a 0.05
94.7
—
83.8 13.1
3.1
—
2a 0.05
0.02
—
—
—
3a 0.05
64.7
59.7
41.7
35.2
33.9
28.4
92.1
85.4
91.4
84.9
90.9
84.1
90.7
84.8
90.1
83.2
89.9
82.7
89.8
81.5
90.2
90.2
90.1
82.9
71.9
59.8
78.2
91.2
74.7 12.9
75.1 12.5
65.7 19.9
65.8 20.0
61.2 28.4
61.3 28.3
12.4
12.4
14.4
14.2
10.4
10.4
2.8
2.9
3.1
3.0
3.3
3.3
2.4
2.3
3.0
2.8
3.1
3.1
3.7
3.6
3.9
3.9
4.0
3.8
3.7
3.6
3.7
4.1
3a 0.05
0.1
—
4a 0.05
4a 0.05
0.1
—
5a 0.05
5a 0.05
0.1
—
1b 0.05
91.2
91.3
91.8
92.0
93.4
93.5
91.9
92.1
91.9
92.3
93.6
93.7
95.1
95.3
94.8
94.8
94.7
95.0
95.2
95.5
95.2
94.7
6.0
5.8
5.1
5.0
3.3
3.2
5.7
5.6
5.1
4.9
3.3
3.2
1.2
1.1
1.3
1.3
1.3
1.2
1.1
0.9
1.1
1.2
1b 0.05
0.1
—
2b 0.05
2b 0.05
0.1
—
3b 0.05
3b 0.05
0.1
—
5b 0.05
5b 0.05
0.1
—
6b 0.05
6b 0.05
0.1
—
This prompted us to prepare a series of platinum acetylide com-
plexes (1b–8b). In comparison with 3a, when the hydrosilylation
reaction was undertaken using a series of platinum–acetylide–
phosphine complexes (1b–8b) as catalysts, both higher catalytic
activity and selectivity for the β-adduct were exhibited. Although
the catalytic activities of platinum–acetylide–phosphine complexes
(1b–4b; 5b–8b) catalysts slightly decreased with increasing steric
hindrances of the alkyne-containing silyl group, the selectivity of
the β-adduct clearly increased. This demonstrated that the
attached substituents of alkyne containing silyl group had a signif-
icant impact on the catalytic process, especially on the selectivity of
the β-adduct. However, in comparison with 1b, when the
hydrosilylation reaction was undertaken by 5b as the catalysts,
the conversion of styrene decreased slightly, while the selectivities
were constant. This demonstrated that the attached substituents of
phosphine ligands had less impact on the catalytic process. At the
same time, platinum–acetylide–phosphine complexes showed a
strong ability to resist sulfur poisoning. Therefore, it can also be
assumed that the alkyne ligands containing a silyl group offered a
strong ability to resist sulfur poisoning and had a strong impact
on the hydrosilylation reaction.
7b 0.05
7b 0.05
0.1
—
8b 0.05
8b 0.05
0.1
—
4b 0.05
4b 0.05
0.02
0.05
0.1
0.2
0.5
0.1
0.1
4b 0.05
4b 0.05
4b 0.05
4b 0.05
4b 0.025
4b 0.1
Reaction conditions: styrene 4.0 mmol; triethoxysilane 4.4 mmol; 90°C; 2 h.
Analyzed by GC-MS; S poison: benzothiazole; by-product:
ethylbenzene; no unsaturated adduct.
1a: trans-Pt(PPh3)2Cl2
2a: trans-Pt [PPh2Si(CH3)3] Cl2
2
3a: trans-Pt(PPh3)2(CꢀCPh)2
4a: trans-Pt(PPh3)2[ꢁCꢀCC(CH3)2OH]2
5a: trans-Pt(PPh3)2[ꢁCꢀC(C6H10)OH]2
1b: trans-Pt(PPh3)2(CꢀCSiMe3)2
Although the conversion of styrene increased with increas-
ing amounts of 4b used, the selectivities were constant
(Table 1, entries 35, 38 and 39). When the hydrosilylation
reaction was undertaken using 4b in the presence of
trace amounts of poisonous sulfur, both the conversion of sty-
rene and the selectivities were constant. Along with the
amounts of sulfur poisoning increasing, the conversions of
styrene decreased, while the selectivities remained constant.
2b: trans-Pt(PPh3)2(CꢀCSiEt3)2
3b: trans-Pt(PPh3)2{CꢀCSi[CH(CH3)2]3}2
4b: trans-Pt(PPh3)2(CꢀCSiPh3)2
5b: trans-Pt[PPh2Si(CH3)3]2[CHꢀCSi (CH3)3]2
6b: trans-Pt[PPh2Si(CH3)3]2[CHꢀCSi (CH2CH3)3]2
7b: trans-Pt[PPh2Si(CH3)3]2[CHꢀCSi (CH(CH3)2)3]2
8b: trans-Pt[PPh2Si(CH3)3]2(CHꢀCSi Ph3)2
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Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 454–460

Platinum–acetylide–phosphine as catalyst for hydrosilylation reactions
Table 3. Results of the hydrosilylation reaction of aliphatic alkenes with triethoxysilane
Selectivity (%)
Unsaturated
Entry
Alkene
S poison (mol%)
Silane
Conv.
β
α
1-Ethylbenzene
1
2-Methylstyrene
—
0.1
—
Triethoxysilane
92.4
85.3
91.4
83.7
89.4
82.5
93.4
86.1
92.1
84.1
95.9
88.7
91.4
84.7
93.1
86.4
95.2
95.4
94.7
94.9
96.1
96.1
95.4
95.6
94.3
94.6
97.4
97.5
98.1
98.0
84.8
85.1
1.4
1.3
1.5
1.5
1.2
1.3
1.5
1.6
1.2
1.3
—
—
—
3.4
3.3
3.8
3.6
2.7
2.6
3.1
2.8
4.5
4.1
2.6
2.5
1.9
2.0
3.9
3.4
2
3
3-Methylstyrene
4-Methylstyrene
4-Methoxystyrene
4-Fluorostyrene
1-Hexene
—
4
0.1
—
—
5
—
6
0.1
—
—
7
—
8
0.1
—
—
9
—
10
11
12
13
14
15
16
0.1
—
—
—
0.1
—
—
—
1-Dodecene
—
—
0.1
—
—
—
Styrene
Triethylsilane
1.3
1.2
10.0
10.3
0.1
Reaction conditions: alkene 40 mmol; silane 44 mmol; S poison: benzothiazole.
Catalyst: trans-Pt(PPh3)2(CꢀCSiPh3)2 (4b) 0.05% based on styrene; 90°C, 5 h.
[2] C. Grish, Y. L. Peter, Organometallics 1987, 6, 191.
[3] B. G. Guillaume, J. M. Schumers, B. D. Guillaume, I. Markó, J. Org.
Chem. 2008, 73, 4190.
[4] L. N. Lewis, N. Lewis, J. Am. Chem. Soc. 1986, 108, 7228.
[5] I. Markó, S. Stérin, O. Buisine, G. Mignani, P. Branlard, B. Tinant,
J. P. Declercq, Science 2002, 298, 204.
[6] O. Buisine, G. Berthon-Gelloz, J. F. Brière, S. Stérin, G. Mignani,
P. Branlard, B. Tinant, J. P. Declercq, I. E. Markó, Chem. Commun.
2005, 5, 3856.
When other alkenes such as 1-hexene, 1-dodecene, 4-
methoxystyrene 4-fluorostyrene, 2-methylstyrene, 3-methylstyrene
and 4-methylstyrene were used as one of the substrates, high
levels of conversion and selectivity were obtained when using
4b as catalyst (Table 3). At the same time, 4b did not lose its
catalytic activity in the presence of trace amounts of poisonous
sulfur. Also, when triethylsilane replaced triethoxysilane as
hydrogen donor, the unsaturated adduct triethyl (styryl) silane
was found.
[7] J. W. Sprengers, M. J. Mars, M. A. Duin, K. J. Cavell, C. J. Elsevier,
J. Organomet. Chem. 2003, 679, 149.
[8] B. D. Guillaume, B. G. Guillaume, T. Bernard, I. E. Markó, Organometallics
2006, 25, 1881.
[9] Y. Yoshikawa, K. Yamamoto, K. M. Tanaka, EP Patent 604.104, 1994.
[10] C. A. Hoag, S. W. Wilson, US Patent 5346723, 1994.
[11] H. Soeda, M. Tsugita, US Patent 5382974, 1995.
[12] A. Fehn, F. Achenbach, EP Patent 994159, 2000.
[13] A. Fehn, F. Achenbach, S. Dietl, DE Patent 19837855, 2000.
[14] J. Li, J. Peng, Y. Deng, C. Ma, G. Zhang, Y. Bai, G. Lai, Appl. Organomet.
Chem. 2012, 26, 461.
[15] X.-X. Guo, J.-H. Xie, G.-H. Hou, W.-J. Shi, L.-X. Wang, Q.-L. Zhou,
Tetrahedron: Asymmetry 2004, 15, 2231.
[16] K. Takaki, K. Sonoda, T. Kousaka, G. Koshoji, T. Shishido, K. Takehira,
Tetrahedron Lett. 2001, 42, 9211.
[17] G. Liu, M.-Z. Cai, J. Mol. Catal. A Chem. 2006, 258, 257.
[18] T. Hayashi, Catal. Today 2000, 62, 3.
[19] I. Weber, G. B. Jones, Tetrahedron Lett. 2001, 42, 6983.
[20] T. Okano, M. Iwahara, H. Konish, J. Kiji, J. Organomet. Chem. 1988,
346, 267.
[21] K. Campbell, R. McDonald, M. J. Ferguson, R. R. Tykwinski,
J. Organomet. Chem. 2003, 683, 379.
[22] J. Li, J. Peng, G. Zhang, Y. Bai, G. Lai, X. Li, New J. Chem. 2010,
34, 1330.
Conclusion
In summary, a series of platinum acetylide complexes were
synthesized. In comparison with Speier’s catalyst, Karstedt’s
catalyst and 3a, when the hydrosilylation reaction was under-
taken using a series of platinum–acetylide–phosphine (1b–8b)
as the catalysts, both higher catalytic activity and selectivity for
the β-adduct were obtained. At the same time, the platinum–
acetylide–phosphine complexes (1b–8b) did not lose their
catalytic activities in the presence of small amount of poisonous
sulfur. It can therefore also be assumed that alkyne ligands
containing the silyl group played an important role in the
hydrosilylation reaction. The platinum–acetylide–phosphine
complexes (1b–8b) exhibited a strong ability to resist sulfur poi-
soning. Also, alkyne ligands containing a silyl group had a strong
impact on the hydrosilylation reaction.
Acknowledgments
[23] Siemens, Stereochemical Workstation Operation Manual,
Release 3.4, Siemens Analytical X-ray Instruments, Madison,
WI, 1989.
[24] G. M. Sheldrick, Acta Crystallogr. 2008, A64, 112.
[25] M. Ravera, R. D. Amato, A. Guerri, J. Organomet. Chem. 2005,
690, 2376.
We are grateful to the Natural Science Foundation of China
(21203049) and the Educational Commission of Zhejiang Province
of China (Y201327588) for financial support.
[26] F. Q. Bai, X. Zhou, B. H. Xia, T. Liu, J. P. Zhang, H. X. Zhang,
J. Organomet. Chem. 2009, 694, 1848.
[27] N. M. Shavaleev, H. Adams, J. Best, J. A. Weinstein, J. Organomet.
Chem. 2007, 692, 921.
References
[1] J. L. Speier, J. A. Webster, G. H. Barnes, J. Am. Chem. Soc. 1957,
79, 574.
[28] L. H. Cheuk, W. Y. Wong, J. Organomet. Chem. 2006, 691, 395.
Appl. Organometal. Chem. 2014, 28, 454–460
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

J. Li et al.
[29] C. Tedeschi, C. Saccavini, L. Maurette, M. Soleilhavoup, R. Chauvin,
J. Organomet. Chem. 2003, 670, 151.
[34] J. R. Berenguer, E. Lalinde, M. T. Moreno, Coord. Chem. Rev. 2010,
254, 832.
[30] U. Belluco, R. Bertani, R. A. Michelin, M. Mozzon, J. Organomet. Chem.
2000, 600, 37.
[31] N. Ohshiro, F. Takei, K. Onitsuka, S. Takahashi, J. Organomet. Chem.
1998, 569, 195.
Supporting Information
[32] J. Lewis, P. R. Raithby, W. Y. Wong, J. Organomet. Chem. 1998, 556, 219.
[33] S. L. James, M. Younus, P. R. Raithby, J. Lewis, J. Organomet. Chem.
1997, 543, 233.
Additional supporting information may be found in the online
version of this article at the publisher’s web-site.
wileyonlinelibrary.com/journal/aoc
Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 454–460