Hydrosilylation of Aldehydes and Ketones Catalysed by Bis(phosphinite) Pincer Platinum Hydride Complexes

Article abstract of DOI:10.1002/adsc.202000166

Bis(phosphinite) pincer platinum hydride complexes, [2,6-(R₂PO)₂C₆H₃]PtH (R=^tBu, ⁱPr), were synthesized, characterized and applied to the hydrosilylation of aldehydes and ketones. NMR study and single crystal X-ray diffraction analysis indicated that the hydrides in these two platinum complexes are comparatively less hydridic: down-field ¹H NMR resonances (0.71 and 0.98 ppm) and weak Pt?H interactions were observed. Both the platinum complexes were found to be good catalysts for the hydrosilylation of aldehydes and ketones with phenylsilane. The corresponding alcohols were isolated in good to excellent yields following basic hydrolysis of the resultant hydrosilylation products and turnover frequencies (TOFs) up to 3200 h^?1 were achieved at 60 °C in toluene, which are much higher than those of the hydrosilylation catalysed by the corresponding nickel pincer hydride complexes. A possible mechanism for the present hydrosilylation process was discussed. (Figure presented.).

Full text of DOI:10.1002/adsc.202000166

Title: Hydrosilylation of Aldehydes and Ketones Catalyzed by
Bis(phosphinite) Pincer Platinum Hydride Complexes
Authors: Jiarui Chang, Fei Fang, Jie Zhang, and Xuenian Chen
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
FULL PAPER
DOI: 10.1002/adsc.201((will be filled in by the editorial staff))
Hydrosilylation of Aldehydes and Ketones Catalysed by
Bis(phosphinite) Pincer Platinum Hydride Complexes
Jiarui Chang,a Fei Fang,a Jie Zhanga,* and Xuenian Chena,b,*
a
Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, Key Laboratory of Green Chemical
Media and Reactions, Ministry of Education, Collaborative Innovation Centre of Henan Province for Green
Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University,
Xinxiang, Henan 453007, China
Fax: (+86)-373-3326336; Phone: (+86)-373-3328655; E-mail: jie.zhang@htu.edu.cn (J. Zhang), xnchen@htu.edu.cn.
(X. Chen).
College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China.
b
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201######.
Abstract. Bis(phosphinite) pincer platinum hydride excellent yields following basic hydrolysis of the resultant
t
i
complexes, [2,6-(R2PO)2C6H3]PtH (R = Bu, Pr), were hydrosilylation products and turnover frequencies (TOFs)
synthesized, characterized and applied to the hydrosilylation up to 3200 h-1 were achieved at 60˚C in toluene, which are
of aldehydes and ketones. NMR study and single crystal X- much higher than those of the hydrosilylation catalysed by
ray diffraction analysis indicated that the hydrides in these the corresponding nickel pincer hydride complexes. A
two platinum complexes are comparatively less hydridic: possible mechanism for the present hydrosilylation process
1
down-field H NMR resonances (0.71 and 0.98 ppm) and was discussed.
weak Pt-H interactions were observed. Both the platinum
complexes were found to be good catalysts for the
hydrosilylation of aldehydes and ketones with phenylsilane.
The corresponding alcohols were isolated in good to
Keywords: Pincer complexes; Platinum hydride;
Hydrosilylation; Aldehydes; Ketones
metal catalysed processes apart from
a
few
exceptions.[3] In order to achieve an acceptable
conversion in a reasonable period of time, higher
Introduction
Catalytic hydrosilylation of aldehydes and ketones has catalyst loadings (up to 10 mol%) were required
been a subject of continuing interests since Ojima and sometimes.[4] It is argued that if a far more efficient
co-workers first reported the Rh-catalysed reduction of catalyst based on a precious metal could be developed
carbonyl compounds with Et3SiH in the early 1970s.[1] for a reaction, a far less amount of catalyst would
Over the past half a century, numerous transition metal suffice, which might offset the cost of catalyst and
complexes derived from many different transition also make the environmental and safety problems not
metals have been successfully applied as serious or even negligible. As a result, exploring the
homogeneous catalysts for this type of reaction and catalytic activities of precious metal complexes to find
great achievements have been made.[2] Like many highly efficient catalysts for a given chemical
other
transition
metal
catalysed
chemical transformation process remains one of the main tasks
transformation processes, the early work in this field for modern chemists.[5]
was mainly focused on precious metal catalysed
Platinum complexes are among the earliest applied
reactions. During the last two decades, however, and most important transition metal catalysts for
considering that the application of precious transition hydrosilylation of olefins.[6,7] However, very limited
metals has many drawbacks such as expensiveness and work has been reported for platinum catalysed
environmental as well as safety issues, researchers are hydrosilylation of carbonyl compounds.[8] For
trying to develop new catalysts for this hydrosilylation platinum catalysed hydrosilylation of carbonyl
process based on first row transition metals which are compounds, the few early work dealt with
earth
abundant
and
comparatively
more hydrosilylation of α,β-unsaturated aldehydes and
environmetnally benign.[2a,b] Up to date, although ketones or asymmetric hydrosilylation of ketones[8a-d]
significant progress has been made, the efficiency of with special attentions being paid mainly to
most first row transition metal catalysed chemoselectivity or stereoselectivity while the few
hydrosilylation of carbonyl compounds is still far recent work was focused largely on methodology of
lower than that of second and third row transition catalysis or properties and structures of the platinum
1
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
complexes with no particular attention being paid to Hz)[9] although it was comparable to that in the
the catalytic activity.[8e-i]
corresponding palladium hydride complex (JP-H = 16.0
In 2009, Guan and co-workers used bis(phosphinite) Hz).[10] The above NMR data indicate that the
pincer (POCOP) nickel hydride complexes to catalyse interaction between the Pt metal centre and the
the hydrosilylation of aldehydes and ketones with hydride in complex 1 is relatively weak and the
PhSiH3 or Ph2SiH2.[9] With a catalyst loading of 0.2 hydride in complex 1 is less hydridic. This is also
mol%, a series of aldehydes and ketones processing evidenced by the fact that a smaller H-Pt coupling
different functional groups were successfully reduced constant (890.0 Hz) was observed in complex 1.[12]
to the corresponding silylethers at room temperature to The 31P{1H} NMR resonance of 1 was shown at 200.4
70˚C. Following basic hydrolysis of the resulting ppm as a singlet with 195Pt satellites (JP-Pt = 3050.0 Hz).
silylethers, the corresponding alcohols were isolated in The solid state FTIR spectra of 1 (Supporting
good yields. Encouraged by Guan’s work, we decided Information, Figure S4) showed a strong absorption at
to explore the catalytic activity of the corresponding 1930 cm-1 corresponding to the Pt-H stretching
platinum hydride complexes towards hydrosilylation vibration, which is comparable to other terminal Pt-H
of aldehydes and ketones. We found that the platinum stretching vibrations reported in the literature (1908 to
hydride complexes are much better catalysts than the 2033 cm-1).[11,13]
nickel complexes for hydrosilylation of aldehydes and
Crystals of 1 suitable for X-ray diffraction analysis
ketones. A turnover frequency (TOF) of around 3000 were obtained from n-hexane solution at room
h-1 can be achieved at 60˚C in toluene solution, which temperature. The molecular structure of 1 based on the
is much higher than that of the corresponding nickel diffraction experiment is shown in Figure 1 along with
hydride complexes.
the selected bond lengths and angles. The Pt centre
adopts a distorted square planar geometry as expected.
The Pt–Cipso and Pt–P bond lengths are comparable to
those of other POCOP pincer platinum complexes
with similar structures.[14] The platinum hydride was
clearly located in the Fourier map and a Pt–H bond
length of 1.72(4) Å was observed, which is
considerably longer than other reported terminal Pt–H
bond lengths (1.56 to 1.68 Å) determined by a
combination of X-ray diffraction analysis and
calculation.[11]
Results and Discussion
Syntheses and Characterization of POCOP Pincer
Platinum Hydride Complexes
Two POCOP pincer platinum hydride complexes,
[2,6-(R2PO)2C6H3]PtH (R = Bu, 1; iPr, 2), were used
t
in the present work to catalyse the hydrosilylation of
aldehydes and ketones. Complexes 1 and 2 were
synthesized by the reactions of the corresponding
platinum chloride complexes with LiAlH4 in THF at
room temperature (Scheme 1).
Scheme 1. Synthses of Complexes 1 and 2.
Complex 1 is stable under a nitrogen atmosphere in
both solid state and solutions and was fully
characterized by multinuclear NMR, FTIR, X-ray
crystallography, HRMS and elemental analysis. The
1H, 13C{1H} and 31P{1H} NMR spectra of complex 1
(Supporting Information, Figure S1−S3) were in good
agreement with the structure shown in Scheme 1. The
1H NMR resonance of the platinum hydride (PtH) in
complex 1 appeared at 0.71 ppm as a virtual triplet (JH-
Figure 1. Thermal ellipsoid plots of complex 1 at the 50%
probability level (for clarity, the hydrogen atoms except that
attached to the platinum atom have been omitted, and the
phenyl and tert-butyl groups have been simplified). The
selected bond lengths (Å) and angles (°): Pt1–C1, 2.022(4);
Pt1–H, 1.72(4); Pt1–P1, 2.2433(12); Pt1–P2, 2.2453(12);
C1–Pt1–H, 175.9(13); P1–Pt1–P2, 160.16(4).
= 16.3 Hz) with 195Pt satellites (JH-Pt = 890.0 Hz).
P
The chemical shift of this hydride was in significant
down-field region compared with those of the
corresponding nickel hydride complex [2,6-
(tBu2PO)2C6H3]NiH (-7.96 ppm),[9] palladium hydride
complex [2,6-(tBu2PO)2C6H3]PdH (-2.48 ppm)[10] and
other closely related multiplatinum hydride complexes
(-5.92 to -3.67 ppm).[11] The H-P coupling constant in
complex 1 was much smaller than that in the
corresponding nickel hydride complex (JH-P = 53.2
Complex 2 was isolated in a low yield (54%). This
complex is unstable either in the solid state or in
solutions even under a nitrogen atmosphere; it was
characterized and used immediately once isolated.
Attempts to obtain impurity-free 1H and 13C{1H} NMR
spectra for complex 2 were unsuccessful although a
good 31P{1H} NMR spectrum was acquired.
Nevertheless, the NMR spectra of 2 (Supporting
2
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
Table 2. Hydrosilylation of Aldehydes Catalysed by
Complexes 1 and 2.
Information, Figure S5−S7) showed the expected
resonances. Similar to complex 1, the 1H NMR
resonance of the platinum hydride (PtH) in complex 2
was displayed in comparatively down-field region
(0.98 ppm) as a virtual triplet (JH-P = 18.0 Hz) with
195Pt satellites (JH-Pt = 888.0 Hz). The 31P{1H} NMR
resonance of 2 was shown at 189.8 ppm as a singlet
with 195Pt satellites (JP-Pt = 3008.9 Hz). The solid state
FTIR spectra of 2 (Supporting Information, Figure S7)
revealed an intense peak at 1939 cm-1 corresponding to
the Pt-H stretching vibration. The HRMS result of 2
was also in good agreement with the structure shown
in Scheme 1.
Time
(h)[a]
Yield
Entry
1
Substrate
Product
(%)[a][b]
0.3/0.6
95/96
95/99
2
1.0/1.5
3
0.5/1.0
0.5
90/90
93
Hydrosilylation of Aldehydes and Ketones
Catalysed by Complexes 1 and 2
4[c]
Since complex 2 is unstable, we first checked the
catalytic activity of complex 1 towards hydrosilylation
of benzaldehyde under different conditions with
PhSiH3, Ph2SiH2, Ph3SiH, Et3SiH or (EtO)3SiH as the
silyl reagent. It was found that complex 1 is active in
catalysing the hydrosilylation of benzaldehyde with
PhSiH3; benzyl alcohol was obtained after basic
hydrolysis of the resulting product (Table 1). The
results of hydrosilylation of benzaldehyde with other
silyl reagents catalysed by complex 1 are detailed in
the Supporting Information (Table S1).
5
6
7
1.0/2.0
0.5/0.8
0.5/0.7
89/89
85/87
94/85
Table 1. Hydrosilylation of Benzaldehyde with PhSiH3
Catalysed by Complex 1.
8
9
0.5/1.0
2.0/3.0
76/91
89/84
Solvent
Temp.
(˚C)
Comp.1 Time Conv.
Yield
(%)b)
(mol%) (h)
(%)a)
toluene
toluene
toluene
toluene
toluene
toluene
n-hexane 60
THF
CH3CN
DMF
25
25
60
60
60
60
0.2
0
0.2
0.1c)
0.01c)
0
0.2
0.2
0.2
0.2
17
32
0.3
0.5
5
32
0.3
0.3
0.3
0.3
96
2
100
100
100
6
95
32
14
44
90
0
10
11
12
3.0/4.0
1.0/2.0
2.0/3.0
95/90
73/86
83/83
97
96
96
trace
84
25
10
36
60
60
60
13[c]
14
0.3
90
a)
Conversions were based on the GC-MS Analysis Results.
b) Isolated Yields. c) 10 mmol of benzaldehyde and 12 mmol
of PhSiH3 were used.
6.0/13.0
84/78
15[c]
2.0
77
As shown in Table 1, no significant hydrosilylation
occurred in toluene in the absence of complex 1;
toluene is the best solvent for this reaction. At 60 °C,
10 mmol of benzaldehyde could be completely
converted to the hydrosilylation product in 0.5 h with
a catalyst loading of 0.1 mol% or in 5 h with a catalyst
loading of 0.01 mol%.
Having established the best conditions for the
present hydrosylilation system, we then explored the
scope of aldehyde substrate with PhSiH3 in toluene at
60 °C using 0.1 mol% of 1 or 0.05 mol% of 2 as the
catalyst. The corresponding alcohols were obtained in
high yields after basic hydrolysis of the resulting silyl
[a] left/right: “left” lists the data for complex 1 catalysed
reactions and “right” displays the data for complex 2
catalysed reactions. [b] isolated yields. [c] the reaction was
performed using complex 1 as the catalyst.
ethers (Table 2). The reactions proceeded cleanly as
indicated by GC-MS analysis.
It can be seen from Table 2 that the reaction was
tolerant of many functional groups such as OMe
(entries 2-4), halogens (entries 6-8), NO2 (entries 10
and 11) and C=C (entry 15). Apart from substituted
3
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
Table 3. Hydrosilylation of Ketones Catalysed by
Complexes 1 and 2.
benzaldehydes, other aromatic aldehydes could also be
effectively reduced (entries 11-14). It would be
difficult to rationalize the relationship between the
nature of the substrate and the relative hydrosilylation
rates from Table 2. Both aldehydes with an electron
donating group (entries 2-5) and those with an electron
withdrawing group (entries 6-10) are less reactive than
the unsubstituted benzaldehyde (entry 1). Similar
result was observed in the corresponding Ni-catalysed
process.[8] It should be noted that a TOF of around
3000 h-1 was obtained using either 1 or 2 as the
catalyst (entry 1). This TOF value is about 10 to 30
times of those achieved in the nickel hydride
complexes catalysed reactions.[9] In most cases, the
TOFs calculated by using the experimental data from
complex 1 catalysed reactions are comparable to those
Time
(h)[a]
Yield
Entry
1
Substrate
Product
(%)[a][b]
1.0/1.0
1.0/1.0
1.0/1.0
1.0
74/75
82/71
78/79
70
2
3
obtained from complex
2
catalysed reactions.
However, considering that complex 2 is unstable and
partly decomposed during the catalytic process,
complex 2 should be more active than complex 1 in
catalysing this type of reaction. This is similar to the
nickel hydride complexes: the POCOP pincer nickel
4[c]
5[d]
6[d]
7[d]
2.0
3.0
1.0
83
82
82
i
hydride with Pr2P arms is more active than that with
tBu2P arms because of the steric effect.[9] A control
experiment indicated that the resultant residue from
the decomposition of complex 2 was inactive in
catalysing the hydrosilylation of aldehydes.
Hydrosilylation of ketones was also investigated
using complexes 1 and 2 as the catalysts under the
same condiotions (Table 3). The expected alcohols
were isolated in good yields following basic
hydrolysis of the hydrosilylation products although a
slightly higher catalyst loading was required in order
to complete the reaction in a reasonable period of time.
The reaction proceeded cleanly as indicated by GC-
MS analysis and was also tolerant of many functional
groups including OMe, halogens and C=C. TOFs of
70–200 h-1 were obtained based on the isolated yields.
[a] left/right: “left” lists the data for complex 1 catalysed
reactions and “right” displays the data for complex 2
catalysed reactions. [b] isolated yields. [c] the reaction was
performed using complex 1 as the catalyst. [d] the reaction
was performed using complex 2 as the catalyst.
ppm (see Supporting Information Figure S9 and S10).
The new NMR resonances were in good agreement
with a species formed by insertion of the carbonyl
group of benzaldehyde into the Pt-H bond in complex
1 (Scheme 2). Efforts to isolate species 3 in
preparative scales failed due to the instability of
complex 3. Interestingly, when 20 equiv. of PhSiH3
was added into the NMR tube, benzyl alcohol was
detected by GC-MS following basic hydrolysis of the
resultant NMR tube reaction mixture. Experimental
details of the NMR tube reaction are provided in the
Supporting Information.
Mechanistic Insights into the Reactions
In order to understand the reaction process, several
control experiments were carried out. Complex 2 is
unstable; it decomposes slowly to form some unknown
species even under a nitrogen atmosphere. The residue
from the decomposition of complex 2 was used to
catalyse the hydrosilylation of benzaldehyde with
PhSiH3 under the same condition. However, no
reaction occurred. Hydrosilylation of benzaldehyde
with PhSiH3 was also performed in the presence of
elemental Hg and no influence was observed.
A NMR tube reaction was carried out to get more
information about the hydrosilylation process.
Complex 1 was dissolved in toluene-d8 in a NMR tube,
and then an excess amount of benzaldehyde (20 equiv.)
was added. The NMR tube was heated to 70˚C and the
Scheme 2. Interaction of Complex
benzaldehyde.
1
with
1
reaction was monitored by H and 31P{1H} NMR
1
spectroscopy. After 12 h, both 31P{1H} and H NMR
spectra showed the complete disappearance of
complex 1 and the formation of a new species: the
31P{1H} NMR spectrum displayed a new singlet at
177.1 ppm with 195Pt satellites (JP-Pt = 3197 Hz) and
the 1H NMR spectrum showed a new singlet at 4.46
The reaction is likely to follow the same mechanism
as nickel hydride catalysed process:[9] insertion of the
carbonyl group of aldehyde or ketone into the
platinum hydride bond resulting the formation of the
platinum alkoxide complex, the latter interact with
4
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
PhSiH3 to form silyl ether and regenerate the platinum ArC), 127.1 (s, ArC), 105.0 (vt, ArC, JC-P = 5.8 Hz), 39.9-
hydride complex.
40.0 (m, C(CH3)3), 28.2-28.3 (m, C(CH3)3). 31P{1H} NMR
(162 MHz, benzene-d6, δ): 200.4 (s, Pt satellites, JP-Pt
=
3050.0 Hz). FTIR (KBr disc): 1930 (s) cm-1. Anal. Calcd for
C22H40O2P2Pt: C, 44.52; H, 6.79. Found: C, 44.62; H, 6.81.
HRMS (ESI): m/z calculated for C22H40O2P2Pt + H+ [M +
H]+ 532.2751, found 532.2727.
Conclusion
In conclusion, we have synthesized and fully
characterized pincer platinum hydride complexes,
[2,6-(R2PO)2C6H3]PtH (R = Bu, 1; Pr, 2). The
platinum hydride in complexes 1 and 2 is less hydridic
compared with the corresponding palladium hydride,
nickel hydride and other platinum hydride complexes.
Preparation of [2,6-(iPr2PO)2C6H3]PtH (2)
t
i
Complex 2 was synthesized similarly from LiAlH4 and [2,6-
(iPr2PO)2C6H3]PtCl. The reaction mixture was stirred at
room temperature for 30 min. Complex 2 was isolated as an
1
unstable colourless crystalline solid in 54% yield. H NMR
Complexes
1
and
2
are good catalysts for
(600 MHz, benzene-d6, δ): 7.03 (t, 1H, ArH, JH-H = 8.0 Hz),
6.92 (d, 2H, ArH, JH-H = 8.0 Hz), 2.10-2.15 (m, 4H,
CH(CH3)2), 1.05-1.14 (m, 24H, CH(CH3)2), 0.98 (vt, Pt
satellites, 1H, PtH, JH-P = 17.0 Hz, JH-Pt = 887.0 Hz).
13C{1H} NMR (151 MHz, benzene-d6, δ): 165.3 (vt, Pt
satellites, ArC, JC-P = 6.5 Hz, JC-Pt = 33.0 Hz), 144.3 (vt, Pt
satellites, ArC, JC-P = 5.9 Hz, JC-Pt = 465.0 Hz), 127.6 (s,
ArC), 104.9-105.0 (m, ArC), 30.2 (vt, Pt satellites,
CH(CH3)2, JC-P = 17.0 Hz, JC-Pt = 58.5 Hz), 18.7 (vt, Pt
satellites, CH(CH3)2, JC-P = 3.9 Hz, JC-Pt = 19.1 Hz), 17.0 (s,
Pt satellites, CH(CH3)2, JC-Pt = 24.5 Hz). 31P{1H} NMR (243
MHz, benzene-d6, δ): 189.8 (s, Pt satellites, JP-Pt = 3013.0
Hz). FTIR (KBr disc): 1939 (s) cm-1. HRMS (ESI): m/z
calculated for C18H32O2P2Pt + H+ [M + H]+ 476.2123, found
476.2107.
hydrosilylation of aldehydes and ketones with
phenylsilane. The reactions are tolerant of many
functional groups including OMe, halogens, NO2 and
C=C. The corresponding alcohols can be obtained in
good to excellent yields after basic hydrolysis of the
resulting silyl ethers, and TOFs up to 3200 h-1 can be
achieved. The reaction is likely to follow the
mechanism of insertion of the carbonyl group into the
platinum hydride bond resulting in the formation of
the platinum alkoxide complex, the latter interact with
PhSiH3 to form silyl ether and regenerate the platinum
hydride complex.
X-ray Single Crystal Diffraction Analysis of Complex 1
The crystals of complex 1 suitable for X-ray diffraction
analysis were obtained from n-hexane solution at room
Experimental Section
General Information
Manipulations for the synthesis and reactions were carried
out under a nitrogen atmosphere using standard Schlenk
techniques. Solvents were distilled from standard drying
agents and degassed before use. NMR spectra were
recorded on a Bruker Advance 600 or 400 MHz
temperature.
A
SuperNova diffractometer (Oxford
Diffraction) was used for the diffraction experiments. The
intensity data were collected at 296 K using mirror-
monochromated Mo Kα radiation (λ = 0.71073 Å). The
frames were integrated with the Bruker APEX2 software
package using a narrow-frame algorithm. The data were
corrected for decay, Lorentz, and polarization eff ects as
well as absorption and beam corrections were made based
on the multi-scan technique. The structures were solved by
a combination of direct methods in SHELXTL and the
diff erence Fourier techniques and refined by using full-
matrix least squares procedures interfaced with the
programme OLEX2.[16,17] Non-hydrogen atoms were refined
with anisotropic displacement parameters. The H-atoms
were either located or calculated and subsequently treated
with a riding model. The crystallographic data and structure
refinement for complex 1 are summarized in the Supporting
Information (Table S2).
1
spectrometer. For H and 13C NMR spectra, the residual
solvent resonances were used to reference the chemical shift
values internally. For 31P NMR spectra, H3PO4 (85%) was
used as an external standard to calibrate the chemical shifts.
Solid state FTIR spectra were recorded with a VECTOR 22
Bruker spectrophotometer at room temperature. GC-MS
analyses were carried out by using a SHIMADZU-(GCMS-
QP2020) instrument. The starting complexes [2,6-
(tBu2PO)2C6H3]PtCl[15] and [2,6-(iPr2PO)2C6H3]PtCl[14c]
were synthesized according to the published procedures or
slight modification of the published procedures.
Preparation of [2,6-(tBu2PO)2C6H3]PtH (1)
To a suspension of LiAlH4 (76 mg, 2.0 mmol) in toluene
(35 mL) was added [2,6-(tBu2PO)2C6H3]PtCl (628 mg, 1.0
mmol). The reaction mixture was stirred at room
temperature for 15 h. The resulting mixture was filtered
through a short plug of Celite to give a colourless solution.
Solvent was evaporated under vacuum and the product was
further purified via recrystallization from hexanes to give
complex 1 as a colourless crystalline solid (427 mg, 72%
yield). 1H NMR (600 MHz, benzene-d6, δ): 7.04 (t, 1H, ArH,
JH-H = 7.7 Hz), 6.93 (d, 2H, ArH, JH-H = 7.7 Hz), 1.29-1.31
CCDC 1980830 contains the supplementary
crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge
Crystallographic Data Centre.
General Procedure for Catalytic Reactions
Aldehyde or ketone (1.0–5.0 mmol) was mixed with 1.2
equiv. of PhSiH3 in a 10 mL flame-dried Schlenk flask.
Toluene (3–5 mL) containing the required catalyst (complex
1 or 2) was added. The mixture was stirred at 60 °C and the
reaction was monitored by using GC-MS. The reaction was
stopped after aldehyde or ketone substrate was consumed
completely. The solvent was then removed under vacuum
(m, 36H, C(CH3)3), 0.71 (vt, Pt satellites, 1H, PtH, JH-P
=
16.5 Hz, JH-Pt = 890.0 Hz). 13C{1H} NMR (151 MHz,
benzene-d6, δ): 166.2 (vt, ArC, JC-P = 5.8 Hz), 145.0 (s,
5
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
and the residue was treated with a 10% aqueous solution of [7] For selected examples, see, a) J. L. Speier, J. A.
NaOH (10 mL). The solution containing the alcohol product
was extracted with diethyl ether for three times, dried over
anhydrous Na2SO4, and concentrated under vacuum. The
desired alcohol was further purified by flash column
chromatography on silica gel using petroleum ether/EtOAc
as the eluent. Conversions were calculated based on the GC
analysis results and TOFs were determined from the
Webster, G. H. Barnes, J. Am. Chem. Soc. 1957, 79,
974−979; b) I. E. Markó, S. Stérin, O. Buisine, G.
Mignani, P. Branlard, B. Tinant, J.-P. Declercq,
Science 2002, 298, 204−206; c) Y. Nishihara, M.
Itazaki, K. Osakada, Tetrahedron Lett. 2002, 43,
2059−2061; d) M. Itazaki, Y. Nishihara, K. Osakada, J.
Org. Chem. 2002, 67, 6889−6895; e) T. Iimura, N.
Akasaka, T. Iwamoto, Organometallics 2016, 35,
4071−4076.
1
isolated yields. The H NMR spectra of the isolated alcohol
products are provided in the Supporting Information (Figure
S11–S32). The spectra were in good agreement with those [8] a) K. Yamamoto, T. Hayashi, M. Kumada, J.
reported in the literature.[9,18-25] The purity of the isolated
alcohol products was calculated from the H NMR spectra.
More details about the reduction products are provided in
the Supporting Information. For the Hg test experiment, the
reactions were carried out similarly but 2 drops of elemental
mercury were added in the reaction flask.
Organomet. Chem. 1972, 46, C65−C67; b) T. Hayashi,
K. Yamamoto, M. Kumada, J. Organomet. Chem.
1976, 112, 253−262; c) A. P. Barlow, N. M. Boag, F.
G. A. Stone, J. Organomet. Chem. 1980, 191, 39−47;
d) W. R. Cullen, S. V. Evans, N. F. Han, J. Trotter,
Inorg. Chem. 1987, 26, 514−519; e) V. V. Zuev, D. A.
de Vekki, Phosphorus, Sulfur, and Silicon 2005, 180,
2071–2083; f) Y. K. Kong, J. Kim, S. Choi, S.-B. Choi,
Tetrahedron Lett. 2007, 48, 2033–2036; g) M. R.
Buchner, B. Bechlars, K. Ruhland, J. Organomet.
Chem. 2013, 744, 60−67; h) M. Tanabe, M. Kamono,
K. Tanaka, K. Osakada, Organometallics 2017, 36,
1929−1935; i) Y. Tsuchido, R. Abe, M. Kamono, K.
Tanaka, M. Tanabe, K. Osakada, B. Chem. Soc. Jpn.
2018, 91, 858−864.
1
Acknowledgements
This work was supported by the National Natural Science
Foundation of China (Grant Numbers 21571052, U1804253 and
21771057).
References
[9] S. Chakraborty, J. A. Krause, H. Guan,
Organometallics 2009, 28, 582−586.
[1] I. Ojima, M. Nihonyanagi, Y. Nagai, J. Chem. Soc.,
Chem. Commun. 1972, 938.
[10] A. Adhikary, J. R. Schwartz, L. M. Meadows, J. A.
Krause, H. Guan, Inorg. Chem. Front. 2014, 1, 71–82.
[11] a) T. Tanase, K. Yamamoto, K. Nakamae, B. Kure, T.
Nakajima, J. Organomet. Chem. 2016, 814, 35−41; b)
F. Novio, P. González-Duarte, A. Lledós, R. Mas-
Ballesté, Chem. Eur. J. 2007, 13, 1047–1063.
[12] See for example, an H-Pt coupling constant of 1305
Hz was reported for a platinum hydride complex, S.
Pal, S. Kusumoto, K. Nozaki, Organometallics 2017,
36, 502−505.
[2] See the following selected reviews and the references
cited therein: a) ꢀ. Raya-Barꢁn, P. Oꢂa-Burgos, I.
Fernꢃndez, ACS Catal. 2019, 9, 5400−5417; b) B.
Royo, Adv. Organomet. Chem. 2019, 72, 59−102; c) S.
Díez-González, S. P. Nolan, Org. Prep. Proced. Int.
2007, 39, 523–559.
[3] See for example, a) J. Yang, T. D. Tilley, Angew.
Chem. Int. Ed. 2010, 49, 10186–10188; b) A. J. Ruddy,
C. M. Kelly, S. M. Crawford, C. A. Wheaton, O. L.
Sydora, B. L. Small, M. Stradiotto, L. Turculet,
Organometallics 2013, 32, 5581–5588; c) T. K.
Mukhopadhyay, M. Flores, T. L. Groy, R. J. Trovitch,
J. Am. Chem. Soc. 2014, 136, 882–885; d) Q. Liang, N.
J. Liu, D. Song, Dalton Trans. 2018, 47, 9889–9896.
[4] See for example, a) H. Nishiyama, A. Furuta, Chem.
Commun. 2007, 760–762; b) Y. Sunada, H. Kawakami,
T. Imaoka, Y. Motoyama, H. Nagashima, Angew.
Chem. Int. Ed. 2009, 48, 9511–9514; c) T. C. Jung, G.
Argouarch, P. Van De Weghe, Catal. Commun. 2016,
78, 52−54.
[5] For examples of recent efforts to develop highly
efficient catalysts for hydrosilylation of carbonyl
compounds based on precious metal complexes, see, a)
C. Nogues, G. Argouarch, Tetrahedron Lett. 2019, 60,
151101; b) B. Chatterjee, C. Gunanathan, Chem.
Commun. 2014, 50, 888–890; c) P. V. Chouthaiwale,
V. Rawat, A. Sudalai, Tetrahedron Lett. 2012, 53,
148–150; d) S. Park, M. Brookhart, Organometallics
2010, 29, 6057–6064.
[6] For selected review articles, see, a) D. Troegel, J.
Stohrer, Coord. Chem. Rev. 2011, 255, 1440–1459; b)
Y. Nakajima, S. Shimada, RSC Adv. 2015, 5,
20603−20616.
[13] R. D. Adams, W. C. Pearl, Jr., Inorg. Chem. 2010, 49,
6188–6195.
[14] a) J. Zhang, B. Cao, Y. Ding, J. Chang, S. Li, X. Chen,
ChemistrySelect 2019, 4, 1292–1297; b) B. Cao, Y.
Ding, F. Fang, J. Chang, J. Zhang, S. Li, X. Chen,
Dalton Trans. 2019, 48, 13760–13768; c) Z. Wang, S.
Sugiarti, C. M. Morales, C. M. Jensen, D. Morales-
Morales, Inorg. Chim. Acta 2006, 359, 1923–1928; d)
N. Á. Espinosa-Jalapa, S. Hernández-Ortega, X.-F. Le
Goff, D. Morales-Morales, J.-P. Djukic, R. Le Lagadec,
Organometallics 2013, 32, 2661–2673; e) N. Á.
Espinosa-Jalapa, S. Hernández-Ortega, D. Morales-
Morales, R. Le Lagadec, J. Organomet. Chem. 2012,
716, 103−109; f) N. A. Espinosa-Jalapa, M. A. R.
Ramires, R. A. Toscano, J.-P. Djukic, R. Le Lagadec,
J. Organomet. Chem. 2017, 845, 125−134; g) B. G.
Anderson, J. L. Spencer, Chem. Eur. J. 2014, 20,
6421–6432; h) M. Joksch, J. Haak, A. Spannenberg, T.
Beweries, Eur. J. Inorg. Chem. 2017, 2017, 3815–
3822; i) M. Joksch, H. Agarwala, J. Haak, A.
Spannenberg, T. Beweries, Polyhedron 2018, 143,
118–125; j) M. Joksch, H. Agarwala, A. Spannenberg,
T. Beweries, Eur. J. Inorg. Chem. 2018, 2018, 3913–
3921.
6
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10.1002/adsc.202000166
Advanced Synthesis & Catalysis
[20] X. Qi, H. Zhao, H. Sun, X. Li, O. Fuhr, D. Fenske,
New J. Chem. 2018, 42, 16583–16590.
[21] Y. Corre, V. Rysak, X. Trivelli, F. Agbossou-
Niedercorn, C. Michon, Eur. J. Org. Chem. 2017,
2017, 4820–4826.
[22] G. Liu, Y. Wang, B. Zhu, L. Zhang, C.-Y. Su, New J.
Chem. 2018, 42, 11358–11363.
[23] C. A. Swamy P., A. Varenikov, G. de Ruiter,
Organometallics 2020, 39, 247–257.
[24] A. Horn, U. Kazmaier, Org. Lett. 2019, 21, 4595–4599.
[25] H. Yang, Y. Li, M. Jiang, J. Wang, H. Fu, Chem. Eur.
J. 2011, 17, 5652–5660.
[15] M. Joksch, J. Haak, A. Spannenberg, T. Beweries, Eur.
J. Inorg. Chem. 2017, 2017, 3815–3822.
[16] G. M. Sheldrick, Acta Crystallogr., Sect. A: Found.
Crystallogr. 2008, 64, 112–122.
[17] O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K.
Howard, H. Puschmann, J. Appl. Crystallogr. 2009, 42,
339–341.
[18] N. S. Shaikh, K. Junge, M. Beller, Org. Lett. 2007, 9,
5429–5432.
[19] P. Bhattacharya, J. A. Krause, H. Guan,
Organometallics 2011, 30, 4720–4729.
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FULL PAPER
Hydrosilylation of Aldehydes and Ketones
Catalysed by Bis(phosphinite) Pincer Platinum
Hydride Complexes
Adv. Synth. Catal. Year, Volume, Page – Page
Jiarui Chang, Fei Fang, Jie Zhang,* Xuenian
Chen*
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