Supplementary Information
for
A Recyclable Catalyst That Precipitates at the End of the Reaction
Vladimir K. Dioumaev and R. Morris Bullock*
All manipulations were performed in Schlenk–type glassware on a dual–manifold
Schlenk line or in a argon–filled Vacuum Atmospheres glovebox. NMR spectra were
obtained on a Bruker Avance 400 FT NMR spectrometer (400 MHz for 1H). All NMR
spectra were recorded at 25 °C unless stated otherwise. Chemical shifts for 1H and
13
C
NMR spectra were referenced using internal solvent resonances and are reported relative
to tetramethylsilane. External standards of trifluorotoluene (set as  = –63.73) and 85 %
H3PO4 (set as  = 0) were used for referencing
19
F and
31
P NMR spectra.
13
C{1H} and
31
P{1H} NMR spectra were recorded with broadband 1H decoupling unless stated
otherwise. For quantitative 1H NMR measurements the relaxation delay was set at 30
seconds. GC–MS spectra were recorded on an Agilent Technologies 5973 mass selective
detector connected to an Agilent Technologies 6890N gas chromatograph equipped with
an HP–5ms column (5 % phenyldimethylpolysiloxane). Infrared spectra were recorded
on a Mattson Polaris spectrometer. Elemental analyses were performed by Schwarzkopf
Microanalytical Laboratory, Inc. (Woodside, NY).
Hydrocarbon solvents were dried over Na/K–benzophenone. Benzene–d6 was
dried over Na/K. Organic carbonyl compounds were dried over CaH2. H2 was used as
1
received. HSiEt3 was dried over LiAlH4. Compounds [CpMo(CO)2(IMes)]+[B(C6F5)4]–
and [CpW(CO)2(IMes)]+[B(C6F5)4]– were synthesized as previously reported.1
Turnover number (TON) is the number of moles of a carbonyl substrate
consumed to yield a given product and is normalized to the number of moles of catalyst.
Note that each equivalent of an ether (R(R’)HCOCH(R’)R) formed in a hydrosilylation
of a ketone (R(R’)C=O) is counted as two turnovers of the catalyst, since it is formed
from two equivalents of a ketone. However, each equivalent of an ether (RCH2OR’)
formed in a hydrosilylation of an ester (RCO2R’) is counted as one turnover of the
catalyst, since it is formed from one equivalent of an ester. Each equivalent of EtOSiEt 3
formed in the hydrosilylation of ethyl acetate (MeCO2Et) is counted as 0.5 turnover of
the catalyst, since it is formed from 0.5 equivalents of an ester. Total TON is the total
number of turnovers for a given product, measured at the end of the reaction.
Synthesis
of
[CpW(CO)2(IMes)(H)2]+[B(C6F5)4]–.
In
a
glovebox
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (30 mg, 0.022 mmol) was suspended in 10 mL
of toluene and placed in a tube equipped with a Teflon valve. The tube was taken out of
the glovebox, filled with about 1.1 atm H2 at –196 ˚C, sealed, and warmed to room
temperature with vigorous stirring.
The colour of the suspension changed almost
immediately from brown to yellow. The mother liquor was removed and discarded, and
the
precipitate
was
dried
in
vacuo
to
yield
[CpW(CO)2(IMes)(H)2]+[B(C6F5)4]– as yellow powder.
26
mg
2
%)
of
pure
The sample in THF–d8 was
found to contain [CpW(CO)2(IMes)(THF–d8)]+[B(C6F5)4]– and
[CpW(CO)2(IMes)(H)2]+[B(C6F5)4]–.
(92
two isomers of
major isomer (ca. 85 %).
1
H NMR (C6D6)  6.74 (s, 4H, m–H–Mes), 6.08 (s, 2H,
=CH), 4.14 (s, 5H, Cp), 2.13 (s, 6H, p–Me–Mes), 1.62 (s, 12H, o–Me–Mes), –1.11 (br s,
2H, WH). 1H NMR (THF–d8, –30 ˚C)  7.82 (s, 2H, =CH), 7.17 (s, 4H, m–H–Mes), 5.46
(s, 5H, Cp), 2.37 (s, 6H, p–Me–Mes), 2.06 (s, 12H, o–Me–Mes), –0.7 (br s, 1/2 = 1400
Hz, 2H, WH).
1
H NMR (THF–d8, –100 ˚C)  7.95 (s, 2H, =CH), 7.19 (s, 4H, m–H–
Mes), 5.59 (s, 5H, Cp), 2.38 (s, 6H, p–Me–Mes), 2.07 (s, 12H, o–Me–Mes), 1.19 (br s,
1/2 = 13 Hz, 1H, WH), –2.97 (~ br d, 1/2 = 12 Hz, 1JHH = 3 Hz, 1JHW = 34 Hz, 1H, WH).
C{1H} NMR (THF–d8, –100 ˚C)  205.2 and 203.1 (s, W–CO), 160.7 (s, NCN), 148.8
13
(br d, 1JCF = 242 Hz, o–C6F5), 141.0 (br s, p–Mes or i–Mes), 139.0 (dm, 1JCF = 242 Hz, p–
C6F5), 138.5 (s, p–Mes or i–Mes), 137.0 (dm, 1JCF = 247 Hz, m–C6F5), 136.4 (br s, o–
Mes), 130.6 and 130.5 (s, m–Mes), 127.9 (br s, =CH), 124.5 (br m, i–C6F5), 88.6 (s, Cp),
21.2 (s, p–Me–Mes), 18.7 and 18.3 (s, o–Me–Mes).
19
F NMR (THF–d8, –30 ˚C)  –133.5
(d, 8F, 3JFF = 11 Hz, o–C6F5), –164.9 (t, 4F, 3JFF = 21 Hz, p–C6F5), –168.5 (t, 8F, 3JFF =
18 Hz, m–C6F5). minor isomer (ca. 15 %).
1
H NMR (C6D6)  6.57 (br s, 4H, m–H–
Mes), 5.97 (br s, 2H, =CH), 3.96 (br s, 5H, Cp), 1.97 (br s, 6H, p–Me–Mes), 1.44 (br s,
12H, o–Me–Mes), –1.25 (br s, 2H, WH2). 1H NMR (THF–d8, –30 ˚C)  7.76 (br s, 2H,
=CH), 5.28 (s, 5H, Cp); other resonances obscured by stronger signals of the major
isomer
of
[CpW(CO)2(IMes)(H)2]+[B(C6F5)4]–
and
by
[CpW(CO)2(IMes)(THF–
d8)]+[B(C6F5)4]–.
IR (Nujol) (CO) = 2073 (vs) and 2018 (vs) cm–1, IR (CF3Ph) (CO) = 2070 (vs) and
2017 (vs) cm–1, IR (THF–d8) (CO) = 2005 (vs) cm–1 (second band obscured by solvent),
3
IR (Et2C=O) (CO) = 2064 (vs) and 2007 (vs) cm–1. Anal. Calcd. for C52H31BF20N2O2W:
C, 48.40; H, 2.42; N, 2.17. Found: C, 47.74; H, 2.14; N, 2.00.
Observation
of
[CpW(CO)2(IMes)(Et2C=O)]+[B(C6F5)4]–.
In
a
glovebox
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (53 mg, 0.038 mmol) and Et2C=O (300 L,
2.83 mmol) were mixed to produce a dark purple solution and placed in an NMR tube
equipped with a Teflon valve. The volatiles were removed in vacuo, and the purple
crystalline material was identified as [CpW(CO)2(IMes)(Et2C=O)]+[B(C6F5)4]–.
1
H NMR (C6D6)  6.6 (br s, 4H, m–H–Mes), 6.10 (s, 2H, =CH), 4.49 (s, 5H, Cp), 2.08 (s,
6H, p–Me–Mes), 1.9 (br s, 4H, CH3CH2), 1.70 (br s, 12H, o–Me–Mes), 0.72 (br s, 6H,
CH3CH2). 1H NMR (Et2C=O and a sealed capillary of CD2Cl2 for lock, –10 ˚C)  8.60
(s, 2H, =CH), 7.85 and 7.75 (br s, 4H, m–H–Mes), 5.98 (s, 5H, Cp), 2.71 (br s, 12H, o–
Me–Mes), resonances of p–Me–Mes and Et presumably obscured by solvent.
13
C{1H}
NMR (liquid clathrate, C6D6)  244.4 (s, W–CO), 239 (br s, Et2C=O), 177 (br s, NCN),
149.4 (dm, 1JCF = 244 Hz, o–C6F5), 141.1 (s, p–Mes or i–Mes; other resonance
presumably obscured by signals around 138), 139.2 (dm, 1JCF = 246 Hz, p–C6F5), 137.3
(dm, 1JCF = 246 Hz, m–C6F5), 136.1 (bs s, o–Mes), m–Mes and =CH obscured by solvent
at 130–127, 125.4 (br m, i–C6F5), 97 (br s, Cp), 36.6 (br s, CH3CH2), 20.9 (s, p–Me–
Mes), 18.0 (br s, o–Me–Mes), 8 (br s, CH3CH2).
13
C{1H} NMR (Et2C=O and a sealed
capillary of CD2Cl2 for lock, –30 ˚C)  248.1 and 246.4 (s, W–CO), 241.1 (s, Et2C=O),
177.4 (s, NCN), 148.7 (dm, 1JCF = 244 Hz, o–C6F5), 140.8 (br s, p–Mes or i–Mes), 138.7
(dm, 1JCF = 247 Hz, p–C6F5), 136.9 (s, p–Mes or i–Mes), 136.7 (dm, 1JCF = 247 Hz, m–
C6F5), 136.7 (s, o–Mes), 130.2 (s, m–Mes), 128 and 126 (br s, =CH), 124.6 (br m, i–C6F5-
4
), 96.0 (s, Cp), 37.8 (s, CH3CH2), 21.0 (s, p–Me–Mes), 18.8, 18.6, and 17.9 (s, o–Me–
Mes), 8.9 (s, CH3CH2).
19
F NMR  (Et2C=O and a sealed capillary of CD2Cl2 for lock, –
30 ˚C) –133.3 (dm, 8F, 3JFF = 11 Hz, o–C6F5), –164.3 (tm, 4F, 3JFF = 21 Hz, p–C6F5), –
168.2 (tm, 8F, 3JFF = 17 Hz, m–C6F5). IR (THF) (CO) = 1963 (vs) and 1863 (vs),
(Et2C=O) = 1718 (w) cm–1. UV(toluene) max = 498 nm ( = 1  103 L mol–1 cm–1).
Synthesis of [CpW(CO)2(IMes)(SiEt3)H]+[B(C6F5)4]–.
In a glovebox a solution of
HSiEt3 (16 L, 0.10 mmol) in 0.5 mL of diethyl ether was added to
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (69 mg, 0.050 mmol). The sample was stirred
for 10 minutes, and the volatiles were removed in vacuo to yield 70 mg (~100 %) of
brown–yellow [CpW(CO)2(IMes)(SiEt3)H]+[B(C6F5)4]–.
major isomer (70 % at 25 ˚C).
1
H NMR (C6D6)  6.74 and 6.69 (s, 2H, m–H–Mes),
6.12 (s, 2H, =CH), 4.64 (s, 5H, Cp), 2.11 (s, 6H, p–Me–Mes), 1.78 and 1.71 (s, 6H, o–
Me–Mes), 0.67 (t, 9H, 3JHH = 8 Hz, CH3CH2), 0.31 (dq, 6H, 3JHH = 2 and 8 Hz, CH3CH2),
–2.60 (s, 1H, 1JHW = 36 Hz, WH).
13
C{1H} NMR (liquid clathrate, C6D6)  217.2 (br s,
CO), 172.3 (s, 1JHW = 134 Hz, NCN), 149.5 (br d, 1JCF = 244 Hz, o–C6F5), 141.0 (s, p–
Mes or i–Mes), 139.3 (dm, 1JCF = 250 Hz, p–C6F5), 137.4 (dm, 1JCF = 250 Hz, m–C6F5),
136.9 (s, p–Mes or i–Mes), 135.7 (s, o–Mes), 130.4 (br s, m–Mes), 125.5 (br m, i–C6F5),
125.4 (s, =CH), 92.2 (s, Cp), 21.1 (s, p–Me–Mes), 18.1 (br s, o–Me–Mes), 5.9 (s,
CH3CH2), 4.7 (s, 1JCSi = 59 Hz, CH3CH2).
19
F NMR  (C6D6) –133.1 (br s, 8F, o–C6F5),
–164.1 (t, 4F, 3JFF = 20 Hz, p–C6F5), –167.9 (br s, 8F, m–C6F5).
29
Si NMR  (C6D6) 43.2
(s, W–Si). minor isomer (30 % at 25 ˚C). 1H NMR (C6D6)  6.60 and 6.56 (br s, 2H,
m–H–Mes), 6.05 (br s, 2H, =CH), 4.46 (br s, 5H, Cp), 1.99 (br s, 6H, p–Me–Mes), 1.63
5
and 1.56 (br s, 6H, o–Me–Mes), 0.54 (br t, 9H, 3JHH = 8 Hz, CH3CH2), 0.20 (br q, 6H,
3
JHH = 8 Hz, CH3CH2), –2.69 (s, 1H, 1JHW = 36 Hz, WH).
IR (CF3Ph) (CO) = 1979 (vs) and 1948 (vs) cm–1, IR (liquid clathrate in CH3Ph) (CO)
= 1981 (vs) and 1940 (vs) cm–1. Anal. Calcd. for C58H45BF20N2O2SiW: C, 49.59; H, 3.23;
N, 1.99. Found: C, 49.33; H, 3.49; N, 2.06.
Catalytic hydrosilylation of aliphatic ketones with HSiEt3.
In a glovebox
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (4 mg, 0.003 mmol), aliphatic ketone (1.50
mmol, 159 L in case of Et2C=O, or 175 L in case of CH2=CH(CH2) 2C(O)Me, or 149
L in case of C3H5C(O)CH3), and HSiEt3 (288 L, 1.80 mmol) were placed in an NMR
tube equipped with a Teflon valve. Two sealed capillaries with C6D6 were placed in the
tube for the purpose of NMR lock.
The tube was shaken to mix the ingredients,
producing a light purple homogeneous solution. The reaction was carried out either at
room temperature (~ 23 °C) or at 53 °C in a constant–temperature bath. The progress of
the reaction was periodically monitored by 1H NMR. At high conversions, the polarity of
the medium drastically decreased and a purple oil separated from the very light purple
solution.
When all of the carbonyl substrate was consumed, the solution turned
colourless and the oil changed colour from purple to yellow and gradually turned into a
solid or a semi–solid.
Determination
of
catalyst
leaching
by
19F
NMR.
In
a
glovebox
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (4 mg, 0.003 mmol), Et2C=O (1.50 mmol, 159
L), and HSiEt3 (288 L, 1.80 mmol) were placed in an NMR tube equipped with a
Teflon valve. Two sealed capillaries with a mixture of C6D6 and C6F6 were placed in the
6
tube as internal standards for signal integration and NMR lock. The tube was shaken to
mix the ingredients, producing a light purple homogeneous solution. The reaction was
left overnight at room temperature (~ 23 °C). The solubility of catalytic species was
detemined by integration of 1H and
19
F NMR spectra of the liquid phase of the final
heterogeneous system (1H NMR  8.5-7.5 ppm, 2H, IMes;
19
F NMR  -162.9 ppm, 4F,
p–C6F5 and –167.8, 8F, m–C6F5) against the internal standards (1H NMR 7.15, s,
residual protons of C6D6; 19F NMR  -162.9, 6F, C6F6) and compared to the results of the
similar integration of the signals in the initial homogeneous mixture. The liquid products
were then decanted, and a new portion of Et2C=O (1.50 mmol, 159 L) and HSiEt3 (288
L, 1.80 mmol) was added. The reaction was left overnight at room temperature (~ 23
°C), and the quantitative NMR experiments were repeated as described above. The
19
F
NMR integration in both cases yielded a consistent residual solubility of ~ 4  10-4 mol L1
for all species containing B(C6F5)4- counter-ion, which corresponds to a leaching of ~5
% of the loaded 0.2 mol % catalyst. The integration of 1H NMR, on the other hand,
yielded no observable species containing IMes ligand, presumably due to a poor
sensitivity for the integration of small individual signals of multiple species as compared
to the
19
F NMR integration of a single collective signal of all B(C6F5)4- containing
species.
Catalytic
hydrosilylation
of
Et2C=O
with
HSiMe2Ph.
In
a
glovebox
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (4 mg, 0.003 mmol), Et2C=O (1.50 mmol, 159
L), and HSiMe2Ph (280 L, 1.80 mmol) were placed in an NMR tube equipped with a
Teflon valve. Two sealed capillaries with C6D6 were placed in the tube for the purpose
7
of NMR lock.
The tube was shaken to mix the ingredients, producing a yellow
homogeneous solution. The reaction was carried out at room temperature (~ 23 °C) and
reached completion before the first NMR measurement (< 15 min).
The mixture
appeared deceptively homogeneous, but small amount of brown oil precipitated after an
overnight period.
Catalytic
hydrosilylation
of
aromatic
ketones.
In
a
glove
box
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (4 mg, 0.003 mmol), aromatic ketone (1.50
mmol, 175 L in case of PhC(O)Me or 182 L in case of p–F–C6H4C(O)CH3), HSiEt3
(288 L, 1.80 mmol), and two sealed capillaries with C6D6 were placed in an NMR tube
equipped with a Teflon valve. The reaction was carried out either at room temperature
(~ 23 °C) or at 53 °C in a constant–temperature bath. The progress of the reaction was
periodically monitored by 1H NMR. The colour gradually changed from purple to light
brown, and small amount of brown oily precipitate was formed.
Determination of the composition of the liquid clathrate formed in the
hydrosilylation of PhC(O)Me. In a glove box [CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph
(40 mg, 0.030 mmol), PhC(O)Me (1.50 mmol, 175 L), and HSiEt3 (288 L, 1.80 mmol)
were mixed and placed in a Pasteur pipet sealed at the narrow end. The pipet was capped
with a rubber septa and was left at room temperature (~ 23 °C) inside the glove-box. The
colour quickly changed from purple to light brown, and brown oily precipitate was
formed in the narrow part of the pipet within ~30 min. The oil proved to be viscous and
difficult to transfer from one vessel to another, and the use of a sealed pipet was a
convenient way to deliver the oil to the narrow part of the pipet. The system was allowed
8
to equilibrate for another 2 h, and the top liquid phase was removed. The bottom section
of the pipet was cut off yielding a capillary filled with brown oil. This capillary and two
sealed capillaries with C6D6 were loaded in an NMR tube equipped with a Teflon valve.
Note that constraining the oil to a narrow capillary was done primarily for the purpose of
better magnetic field homogeneity throughout the sample and therefore, better resolution
in the NMR spectra.
spectroscopy
to
The composition of the oil was determined by 1H NMR
have
~3.4
equivalents
of
PhCH(CH3)OSiEt3
per
[CpW(CO)2(IMes)H2]+[B(C6F5)4]–.
1
H NMR (neat)  7.0 and 6.9 (overlapping br s, 1/2 ~ 150 Hz, 5H of Ph and 6H of IMes),
4.6 (br s, 1/2 = 150 Hz, 1H of PhCH and 5H of Cp), 1.9 and 1.7 (overlapping br s, 1/2 ~
300 Hz, 18H, IMes), 1.1 (br s, 1/2 ~ 150 Hz, 3H, MeCHOSi), 0.7 (br s, 1/2 ~ 150 Hz,
9H, MeCH2Si) , 0.3 (br s, 1/2 ~ 150 Hz, 6H, MeCH2Si), -1.1 (br s, 1/2 ~ 200 Hz, 2H,
WH2).
Catalytic
hydrosilylation
of
ethyl
acetate.
In
a
glove
box
[CpW(CO)2(IMes)]+[B(C6F5)4]–  CH3Ph (2.8 mg, 0.002 mmol), ethyl acetate (98 L,
1.00 mmol), HSiEt3 (352 L, 2.20 mmol), and two sealed capillaries with C6D6 were
placed in an NMR tube equipped with a Teflon valve. The reaction was carried out at
room temperature (~23 °C). At high conversions polarity of the medium drastically
decreased and a purple oil separated from a very light purple solution. When all carbonyl
substrate was consumed, the solution turned colourless and the oil changed colour from
purple to yellow and gradually turned into a solid or a semi–solid.
9
Characterization of products of hydrosilylation. The products were characterized by
GC–MS,
1
H, and
13
C NMR.
Identification of Et2CHOSiEt3,2 EtOSiEt3,3 and
PhCH(CH3)OSiEt3,4 agreed with the previously reported spectroscopic data.
Et2CHOSiEt3: 1H NMR (CDCl3)  3.53 (quintet, 1H, 3JHH = 6 Hz, Et2CH), 1.47 (m, 4H,
CH2CH), 0.98 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.89 (t, 6H, 3JHH = 8 Hz, CH3CH2CH),
0.62 (q, 6H, 3JHH = 8 Hz, CH3CH2Si). 1H NMR (C6D6)  3.48 (quintet, 1H, 3JHH = 6 Hz,
Et2CH), 1.44 (m, 4H, CH2CH), 1.01 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.87 (t, 6H, 3JHH =
8 Hz, CH3CH2CH), 0.60 (q, 6H, 3JHH = 8 Hz, CH3CH2Si).
13
C NMR (CDCl3)  75.0 (s,
Et2CH), 29.6 (s, CH2CH), 9.9 (s, CH3CH2CH), 7.1 (s, CH3CH2Si), 5.3 (s, 1JCSi = 59 Hz,
CH3CH2Si). MS, m/z 201 ((M–H)+, 1), 173 (95), 103 (100), 75 (80).
(Et2CH)2O: 1H NMR (CDCl3)  3.16 (quintet, 1H, 3JHH = 6 Hz, Et2CH), 1.47 (m, 4H,
CH2CH), 0.89 (t, 6H, 3JHH = 8 Hz, CH3CH2CH). 1H NMR (C6D6)  3.04 (quintet, 1H,
3
JHH = 6 Hz, Et2CH), 1.44 (m, 4H, CH2CH), 0.87 (t, 6H, 3JHH = 8 Hz, CH3CH2CH).
13
C
NMR (CDCl3)  79.7 (s, Et2CH), 26.6 (s, CH2CH), 9.9 (s, CH3CH2CH). MS, m/z 129
((M–Et)+, 20), 71 (40), 59 (100).
Et2CHOSiMe2Ph: 1H NMR (CDCl3)  7.66 (m, 2H, o–Ph), 7.41 (m, 3H, m–Ph and p–
Ph), 3.60 (quintet, 1H, 3JHH = 6 Hz, Et2CH), 1.50 (m, 4H, CH2CH), 0.90 (t, 6H, 3JHH = 7
Hz, CH3CH2CH), 0.45 (s, 6H, CH3Si). 1H NMR (C6D6)  7.60 (m, 2H, o-Ph), 7.27 (m,
3H, m-Ph and p-Ph), 3.50 (quintet, 1H, 3JHH = 6 Hz, Et2CH), 1.46 (m, 4H, CH2CH), 0.88
(t, 6H, 3JHH = 7 Hz, CH3CH2CH), 0.39 (s, 6H, CH3Si).
13
C NMR (CDCl3) 138.9 (s, i–
Ph), 133.8 (s, o–Ph), 129.6 (s, p–Ph), 127.9 (s, m–Ph), 75.6 (s, Et2CH), 29.5 (s, CH2CH),
10
10.0 (s, CH3CH2CH), -0.7 (s, 1JCSi = 61 Hz, CH3Si). MS, m/z 221 ((M–H)+, <0.1), 207
(5), 193 (40), 137 (60), 135 (100).
CH2=CH(CH2) 2CH(Me)OSiEt3: 1H NMR (CDCl3)  5.80 (m, 1H, HC=), 4.99 (dq, 1H,
JHH = 17 and 2 Hz, H2C=), 4.92 (dm, 1H, JHH = 10 Hz, H2C=), 3.80 (sextet, 1H, 3JHH = 6
Hz, SiOCH), 2.08 (m, 2H, CH2CH=), 1.50 (m, 2H, CH2CH2CH=), 1.13 (d, 3JHH = 6 Hz,
3H, Me), 0.95 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.59 (q, 6H, 3JHH = 8 Hz, CH3CH2Si).
13
C
NMR (CDCl3)  139.0 (s, HC=), 114.4 (s, H2C=), 68.1 (s, SiOCH), 39.2 and 30.3 (s,
CH2), 24.0 (s, Me), 7.1 (s, CH3CH2Si), 5.2 (s, 1JCSi = 59 Hz, CH3CH2Si). MS, m/z 213
((M–H)+, <0.1), 185 (40), 103 (100), 75 (60).
PhCH(CH3)OSiEt3: 1H NMR (CDCl3)  7.43 (m, 2H, Ph), 7.39 (m, 2H, Ph), 7.30 (m,
1H, Ph), 4.97 (q, 1H, 3JHH = 6 Hz, CH3CH), 1.53 (d, 3H, 3JHH = 6 Hz, CH3CH), 1.03 (t,
9H, 3JHH = 8 Hz, CH3CH2Si), 0.68 (dq, 6H, 3JHH = 4 and 8 Hz, CH3CH2Si). 1H NMR
(C6D6)  7.33 (m, 2H, Ph), 7.18 (m, 2H, Ph), 7.07 (m, 1H, Ph), 4.77 (q, 1H, 3JHH = 6 Hz,
CH3CH), 1.40 (d, 3H, 3JHH = 6 Hz, CH3CH), 0.94 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.56
(dq, 6H, 3JHH = 4 and 8 Hz, CH3CH2Si).
13
C NMR (CDCl3)  147.1 (s, i–Ph), 128.3 (s,
o– or m–Ph), 127.0 (s, p–Ph), 125.4 (s, o– or m–Ph), 70.8 (s, CHCH3), 27.5 (s, CH3CH),
7.0 (s, CH3CH2Si), 5.1 (s, 1JCSi = 59 Hz, CH3CH2Si). MS spectrum matched with NIST
database.
p–F–C6H4–CH(CH3)OSiEt3: 1H NMR (CDCl3)  7.39 (m, 2H, Ar), 7.05 (tt, 2H, JHH = 3
and 9 Hz, Ar), 4.95 (q, 1H, 3JHH = 6 Hz, CH3CH), 1.50 (d, 3H, 3JHH = 6 Hz, CH3CH),
1.02 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.67 (dq, 6H, 3JHH = 3 and 8 Hz, CH3CH2Si). 1H
NMR (C6D6)  7.10 (m, 2H, Ar), 6.82 (m, 2H, Ar), 4.66 (q, 1H, 3JHH = 6 Hz, CH3CH),
11
1.30 (d, 3H, 3JHH = 6 Hz, CH3CH), 0.93 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.53 (dq, 6H,
3
JHH = 3 and 8 Hz, CH3CH2Si).
13
C NMR (CDCl3)  162.1 (d, 1JCF = 244 Hz, Ar), 143.0
(d, 4JCF = 3 Hz, Ar), 126.9 (d, 3JCF = 8 Hz, Ar), 115.0 (d, 2JCF = 21 Hz, Ar), 70.3 (s,
CHCH3), 27.5 (s, CH3CH), 6.9 (s, CH3CH2Si), 5.1 (s, 1JCSi = 59 Hz, CH3CH2Si). MS
matched with NIST database.
C3H5CH(CH3)OSiEt3: 1H NMR (CDCl3)  3.10 (q, 1H, 3JHH = 6 Hz, CH3CH), 1.08 (d,
3H, 3JHH = 6 Hz, CH3CH), 0.82 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.72 (m, 1H,
CHCHCH3), 0.44 (q, 6H, 3JHH = 8 Hz, CH3CH2Si), 0.27 (m, 2H, CH2CH), 0.12 (m, 1H,
CH2CH), –0.02 (m, 1H, CH2CH).
13
C NMR (CDCl3)  72.3 (s, CH3CH), 24.0 (s,
CH3CH), 19.3 (s, CHCHCH3), 7.0 (s, CH3CH2Si), 5.3 (s, 1JCSi = 59 Hz, CH3CH2Si), 3.3
(s, CH2CH), 2.1 (s, CH2CH). MS, m/z 171 ((M–Et)+, 80), 143 (85), 103 (100), 75 (95).
CH3CH=CH(CH2)2OSiEt3: 1H NMR (CDCl3)  5.30 (m, 2H, =CH), 3.46 (t, 2H, 3JHH =
7 Hz, CH2O), 2.07 (q, 2H, 3JHH = 7 Hz, CH2CH2O), 1.50 (d, 3H, 3JHH = 6 Hz, CH3CH=),
0.79 (t, 9H, 3JHH = 8 Hz, CH3CH2Si), 0.38 (q, 6H, 3JHH = 8 Hz, CH3CH2Si).
13
C NMR
(CDCl3)  127.8 (s, =CH), 127.0 (s, =CH), 63.2 (s, CH2O), 36.6 (s, CH2CH2O), 18.1 (s,
CH3CH=), 6.9 (s, CH3CH2Si), 4.7 (s, 1JCSi = 59 Hz, CH3CH2Si). MS, m/z 171 ((M–Et)+,
100), 117 (90), 115 (70), 75 (75).
12
References and Notes
1.
Dioumaev, V. K., Szalda, D. J., Hanson, J., Franz, J. A. & Bullock, R. M. Chem.
Commun., in press (2003).
2.
Itoh, K. & Ibaraki, T. Bull. Chem. Soc. Jpn. 55, 2973-2975 (1982).
3.
Gregg, B. T. & Cutler, A. R. J. Am. Chem. Soc. 118, 10069-10084 (1996).
4.
Deneux, M., Akhrem, I. C., Avetissian, D. V., Myssoff, E. I. & Vol'pin, M. E.
Bull. Soc. Chim. Fr., 2638 (1973).
13
Table 1.
Hydrosilylation of ketones with [CpMo(CO)2(IMes)]+[B(C6F5)4]– (1Mo)
catalysts. All reactions were conducted in neat liquid substrates without solvent: ketone /
HSiEt3 / 1Mo = 100 / 120 / 0.2. Turnover number (TON) is the number of moles of
ketone consumed to yield a given product per the number of moles of catalyst. TOF is the
average
initial turnover frequency measured within the first 15–20 minutes of the
reaction (TOF = TON / time). Total TON is a total number of turnovers for a given
product, measured at the end of the reaction. a n. d. – not determined
substrate
O
products
OSiEt3
time
h
T
°C
25
23
1.2
53
n. d.b
1
<1
0
0
0
10
12
2
n. d.
1
<1
0
0
0
OSiEt3
~1
12
2
23
23
OSiEt3
0
10
0
111
0
22
23
53
0
0
0
O
O
yield
%
6
OSiEt3
O
total
TON
29
O
O
initial
TOF
h–1
10
14