Supplementary Material for Chemical Communications
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1
Supplementary data
Cleavage of Si-Ar bond vs Si-Me bond :
a remarkable counterion effect on reactivity
Suresh Kumar Tipparaju, Sunil K. Mandal, Surojit Sur¶, Vedavati G. Puranik§ and
Amitabha Sarkar*
SUPPORTING INFORMATION
Spectroscopic data :
Complex (1).
Red solid (m.p. 96-97 oC). IR (Nujol): 1973, 1900, 1666, 1607 cm-1. 1H NMR (200 MHz,
CDCL3):  7.88 (d, J = 15 Hz, 1H), 7.67-7.63 (m, 2H), 7.45-7.43 (m, 3H), 7.20 (d, J = 15
Hz, 1H), 5.76 (d, J = 6 Hz, 1H), 5.61-5.43 (m, 4H), 0.36 (s, 9H). 13C NMR (50.32 MHz,
CDCl3): 231.8, 145.8, 134.3, 131.1, 129.1, 128.7, 120.9, 107.7, 101.1, 98.8, 93.3, 92.6,
0.4. Anal. Calcd for C21H20CrSiO4: C, 60.56; H, 4.84. Found: C, 60.62; H, 4.83.
*Complex (2a).
Yellow Solid (m.p. 137-138 oC). IR (Nujol): 3535, 1961, 1894, 1873 cm-1. 1H NMR (300
MHz, CDCl3):  7.47 (d, J = 6 Hz, 2H), 7.40-7.27 (m, 3H), 6.78 (d, J = 16 Hz, 1H), 6.46
(d, J = 16 Hz, 1H), 5.89-5.75 (m, 1H), 5.70 (d, J = 6 Hz, 1H), 5.58 (t, J = 6 Hz , 1H), 5.27
(d, J = 8 Hz, 1H), 5.19-5.07 (m, 2H), 2.78-2.63 (m, 2H), 2.46 (s, 1H), 0.43 (s, 9H). 13C
NMR (75.48 MHz, CDCl3): 233.1, 136.2, 132.5, 132.2, 131.3, 128.7, 128.2, 126.8, 125.6,
120.9, 101.8, 96.5, 95.2, 89.7, 89.5, 76.5, 49.1, 3.5. Anal. Calcd for C24H26CrSiO4 : C,
62.86; H, 5.72. Found: C, 62.39; H, 5.55.
Complex (2b).
Yellow Solid (m.p. 98-99 oC). IR (Nujol): 3547, 1960, 1877, 1861 cm-1. 1H NMR (300
MHz, CDCl3):  7.35-7.27 (m, 5H), 6.43 (d, J = 16 Hz, 1H), 6.31 (d, J = 16 Hz, 1H),
6.02-5.88 (m, 1H), 5.70 (d, J = 6 Hz, 1H), 5.63 (t, J = 6 Hz, 1H), 5.40 (d, J = 12 Hz, 2H),
5.27-5.23 (m, 2H), 2.96-2.81 (m, 2H), 2.62 (s, 1H), 0.38 (s, 9H). 13C NMR (75.48 MHz,
CDCl3): 233.4, 136.2, 135.6, 132.0, 130.0, 128.7, 128.0, 126.6, 126.2, 122.1, 101.5, 98.8,
94.6, 90.7, 89.5, 75.4, 46.9, 3.3. Anal. Calcd for C24H26CrSiO4: C, 62.86; H, 5.72. Found:
C, 62.67; H, 5.85.
Complex (2').
Red oil. IR (Nujol): 1965 (s), 1693 (s), 1641 (m) cm-1. 1H NMR(200 MHz,CDCL3): 
7.35-7.19 (m, 5H), 5.77-5.64 (m, 2H), 5.49-5.45 (m, 3H), 5.08-4.98 (m, 2H), 3.44

Present address : University of Utah, Salt Lake City, USA.
Present address : John Hopkins University, Baltimore, USA.
§
Division of Physical Chemistry
+
Present address : Indian Association for the Cultivation of Science, Kolkata, India.
¶
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
2
(quintet, J = 7 Hz 1H), 3.17-32.99 (m, 2H), 2.45 (t, J = 7 Hz, 2H), 0.18 (s, 9H). 13C
NMR(50.32, MHz, CDCl3): 231.4, 143.4, 136.1, 128.5, 127.5, 126.5, 117.0, 104.0, 102.0,
98.2, 93.4, 91.8, 43.5, 40.7, 40.5, 0.4. Anal.Calcd for: C, 62.86; H, 5.72.Found: C, 63.52;
H, 6.02.
Complex (3).
Yellow Solid (m.p. 108oC). IR (Nujol): 1958, 1884, 1867 cm-1. 1H NMR (300 MHz,
CDCl3):  7.54-7.34 (m, 5H), 6.70 (d, J = 16 Hz, 1H), 6.50 (d, J = 16 Hz, 1H), 5.925.72(m, 2H), 5.44 (t, J= 6 Hz, 1H), 5.29-4.94 (m, 5H), 2.93 (dd, J = 7, 14 Hz, 1H), 2.64
(dd, J = 7, 14 Hz, 1H), 0.21 (s, 9H). 13C NMR (75.48 MHz, CDCl3): 233.2, 136.0, 133.7,
132.6, 130.5, 128.9, 128.3, 126.8, 118.9, 116.8, 94.6, 94.1, 93.4, 89.2, 88.9, 46.2, 2.2.
Anal.Calcd for C24H26CrSiO4: C, 62.86; H, 5.72. Found: C, 62.42; H, 5.84.
Complex (4a).
Yellow Solid (m.p. 98oC). IR (Nujol): 1962, 1892, 1871 cm-1. 1H NMR (200 MHz,
CDCl3):  7.48-7.25 (m, 5H), 6.79 (d, J = 15 Hz, 1H), 6.37 (d, J = 15 Hz, 1H), 5.79-5.58
(m, 1H), 5.55-5.48 (m, 2H), 5.34 (d, J = 6 Hz, 1H), 5.18 (d, J = 6 Hz, 1H), 5.13-4.99 (m,
2H), 2.60 (d of AB quartet, J = 7, 14 Hz, 2H), 0.66 (s, 3H), 0.50 (s, 3H). 13C NMR (50.32
MHz, CDCl3): 232.3, 159.6, 136.5, 132.4, 131.8, 128.5, 128.4, 128.0, 127.5, 126.8,
119.2, 116.8, 96.0, 93.8, 93.5, 90.5, 86.5, 85.2, 49.4, 1.7. Anal.Calcd for C23H22CrSiO4:
C, 62.43; H, 5.01. Found: C, 62.08; H, 5.11.
Complex (4b).
Yellow Solid (m.p. 119oC). IR (Nujol): 1965, 1887, 1867 cm-1. 1H NMR (300 MHz,
CDCl3):  7.32-7.27 (m, 5H), 6.53 (d, J = 16 Hz, 1H), 6.23 (d, J = 16 Hz, 1H), 6.01-5.88
(m, 1H), 5.48-5.45 (m, 3H ), 5.31-5.17 (m, 3H), 2.81 (d of AB quartet, J = 7, 14 Hz, 2H),
0.68 (s, 3H), 0.45 (s, 3H). 13C NMR (50.32 MHz, CDCl3): 232.7, 136.2, 134.2, 133.0,
129.1, 128.6, 127.9, 126.6, 118.7, 93.1, 92.4, 92.0, 88.1, 84.8, 47.5, 1.9, 0.1. Anal.Calcd
for C23H22CrSiO4: C, 62.43; H, 5.01. Found: C, 62.15; H, 4.81.
*Data of the analogous complexes reported :
p-Tolyl analogue of complex 2a :
ref 6 : Sur, S.; Mandal, S. K.; Ganesh, S.; Puranik, V. G.; Sarkar, A. Indian J. Chem. Sect.B.
2001, 40B, 1063-1071
Yellow Crystalline solid, m.p. 164 C;IR (Nujol): 3030, 1960, 1880 cm-1;1H NMR(200
MHz, CDCl3):  7.40 (d, 2H, J = 9 Hz); 7.20 (d, 2H, J = 9 Hz); 6.75 (d, 1H, J = 16 Hz);
6.40 (d, 1H, J = 16 Hz); 5.70-5.95 (m, 2H); 5.60 (t, 1H, J = 6 Hz); 5.25 (m, 2H); 5.10 (m,
2H); 2.40 (m, 2H); 2.45 (s, 3H); 2.75 (m, 2H); 0.45 (s, 9H) 13C NMR : 233.4, 138.2,
133.6, 132.7, 131.3, 129.6, 129.4, 126.9, 126.1, 121.0, 102.1, 90.0, 89.8, 49.2, 21.4, 3.7
Anal. Calcd for C25H28CrSiO4: C 63.54; H,5.97. Found: C,63.21; H,5.90. The crystal
structure of this compound is given below.
3
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
C19
C18
C17
C21
C7
O1
Si
C9
C8
C15
C6
C22
C1
C10
C14
C5
C3
C20
C2
C4
Cr
C16
C11
C24
C13
C12
O3
C25
O4
C23
O2
Experimental Section
All reactions were performed under an inert atmosphere of argon, using freshly distilled
and degassed solvents. Infrared spectra were recorded on a Perkin-Elmer 599B
spectrometer in Nujol. NMR spectra were recorded on a Bruker AC 200 operating at 1H
(200 MHz) and 13C (50.3 MHz) and Bruker MSL-300 operating at 1H (300 MHz) and 13C
(75.48 MHz) spectrometers in CDCl3. Chemical shifts are reported in ppm downfield
from TMS. Elemental analyses were carried out on a Carlo-Erba 1100 automatic analyzer
by the analysts at NCL. Melting points in the Celsius scale were determined in open
capillary tubes on a Thermonik Campbell melting point apparatus and are uncorrected.
Usual workup comprised of quenching the reaction mixture with saturated NH4Cl
solution at 0 0C, extraction with ether followed by evaporation of solvent in vaccum.
a) Preparation of enone 1
A solution of benzaldehyde (280 mg, 2.64 mmol) and the ortho-trimethylsilyl
acetophenone chromium tricarbonyl complex (577 mg, 1.76 mmol) in ethanol (10 mL)
was cooled in ice salt bath. An ethanolic solution of KOH (99mg, 1.76 mmol) in 10 mL
ethanol was added dropwise via a syringe. The reaction was monitored by TLC. After
complete disappearance of starting material, ethanol was removed under reduced pressure
and washed with water. The residue was extracted with dichloromethane. Removal of
solvent provided the enone as red solid product 1. The crude solid product was washed
with pet ether (3 x 20 mL) and recrystallized from dichloromethane-pet ether to afford
analytically pure sample (695mg, 95%).
b) Reaction of 1 with Allylmagnesium Bromide- isolation of carbinols.
To a solution of 1 (175 mg, 0.42 mmol ) in 5ml ether cooled to –78 0C in a dry iceacetone bath freshly prepared allylmagnesium bromide (0.84 mmol, 0.84 ml from 1M
ether solution) was added dropwise during which color of the reaction mixture turned
from dark red to greenish yellow. The reaction was complete in 15 min (TLC). It was
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
4
quenched at same temperature with saturated NH4Cl and extracted with ether to furnish
crude product. Purification by flash column chromatography (2 % acetone: pet ether )
provided 2a (87mg, 45%) and 2b (98mg, 51%).
c) Reaction of 1 with Allyllithium- isolation of carbinol 2a and conjugate addition
product 2′.
To a solution of 1 (183mg, 0.44 mmol) in 5 ml ether cooled to –78 0C was added
allyllithium (0.52 mmol, 1.04 ml from 0.5 M THF solution) dropwise when the color of
the reaction mixture turned from dark red to orange yellow. The reaction was complete in
15 min (TLC). It was quenched at same temperature with saturated NH4Cl and extracted
with ether followed by evaporation of solvent gave the crude product. Purification by
flash column chromatography (2 % acetone: pet ether ) provided 2a (78mg, 39 %) and
the conjugate addition product 2′ (95mg, 47%).
d) Brook rearrangement of allyllithium addition on 1:
To a solution of 1 (250mg, 0.6 mmol) in 6 ml ether cooled to –78 0C was added
allyllithium (0.72 mmol, 1.44 ml from 0.5 M THF solution) dropwise during which the
color of reaction mixture turned from dark red to orange yellow. It was allowed to warm
up to room temperature (3 h) and was stirred for further 8 h. At the end, the reaction
mixture was blackish green in color. After usual workup a crude product was obtained
which was purified by flash column chromatography (2 % acetone : pet ether) affording 3
(110 mg, 40 %) and the conjugate addition product 2′ (124 mg, 45 %).
e) Brook rearrangement of carbinol 2a :
To a solution of 2a (137 mg, 0.3 mmol) in 4 ml ether cooled to –78 0C was added nBuLi (0.45 mmol, 0.27 ml from 1.66 M n-hexane solution) dropwise. There was no
change in the color. It was allowed to warm up to room temperature (3 h) and was stirred
for further 8 h. At the end, the reaction mixture was blackish green in color. Usual
workup gave the crude product which was purified by flash column chromatography (2
% acetone: pet ether) affording 3 (139 mg, 92 %).
f) Exchange of Li with Magnesium counterion :
Allyllithium was added (0.58 mmol, 1.2 ml from 0.5 M THF solution) dropwise to a
solution of 1 (200mg, 0.48 mmol ) in 5 ml ether cooled to –78 0C when the color of the
reaction mixture turned from dark red to orange yellow. The reaction was complete in 15
min (TLC). At this point was added MgBr2.OEt2 (1.44 mmol dissolved in 3 ml of dry
ether) dropwise through a syringe. The reaction mixture was then allowed to warm up to
room temperature (3 h) and was stirred for further 8 h. At the end, the reaction mixture
was greenish brown in color. Usual workup gave the crude product which was purified
by flash column chromatography (3 % acetone: pet ether ) to afford 4a (85 mg, 40 %) and
the conjugate addition product 2′(94 mg, 44 %).
g) Si-O cyclization- One pot procedure: formation of 4 from enone 1.
To a solution of 1 (416 mg, 1 mmol ) in 10 ml ether cooled to –78 0C was added freshly
prepared allylmagnesium bromide (3 mmol, 3 ml from 1M ether solution) over 5 min
during which period the color of the reaction mixture turned from dark red to greenish
yellow. It was allowed to warm up to room temperature (3 h) and was stirred for further 8
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
5
h. At the end, the reaction mixture was orange in color. Usual work up gave the crude
product which was filtered through a pad of neutral alumina. Evaporation of solvent
followed by crystallization from ether/pentane at < 5 0C afforded 4b (234 mg, 53%).
Mother liquor was filtered through alumina and concentrated. Crystallization of the
residue from DCM/pet ether provided 4a (186 mg, 45%).
h) Cyclization in presence of benzophenone : Trapping the Methyl anion.
To a solution of 1 (832 mg, 2 mmol ) in 20 ml ether cooled to –78 0C was added freshly
prepared allylmagnesium bromide (6 mmol, 6 ml from 1M ether solution) over 6-8 min
during which period the color of the reaction mixture turned from dark red to greenish
yellow. Benzophenone (437 mg, 2.4 mmol in 3 ml dry ether) was added dropwise
through a syringe to this mixture at the same temperature. It was allowed to warm up to
room temperature (3 h) and was stirred for further 8 h. At the end, the reaction mixture
was orange in color. Usual workup gave the crude product which was filtered through a
pad of neutral alumina. Purification by flash column chromatography (2 % acetone : pet
ether) provided 4 (725 mg, 82 % as 1:1.2 mixture of 4a and 4b) and diphenyl methyl
carbinol (352 mg, 74 %).
i) Reaction of 4a with MeLi : Low temperature workup.
To a solution of 4a (203 mg, 0.46 mmol ) in 5 ml ether cooled to –78 0C was added
MeLi (0.69 mmol, 0.5 ml from 1.33 M ether solution) dropwise. There was no change in
the color. The reaction was complete in 15 min (TLC). Quenching at same temperature
with saturated NH4Cl solution and extraction with ether gave the crude product.
Purification by flash column chromatography (5 % acetone: pet ether) provided 2a (190
mg, 85 %).
j) Reaction of 4a with MeLi : room temperature, longer time.
To a solution of 4a (115 mg, 0.26 mmol) in 5 ml ether cooled to –78 0C was added
MeLi (0.39 mmol,0.3 ml from 1.33 M ether solution) dropwise. There was no change in
the color. It was allowed to warm up to room temperature (3 h) and was stirred for further
8 h. At the end, the reaction mixture was blackish green in color. Usual workup gave the
crude product which was purified by flash column chromatography (2 % acetone : pet
ether) affording 3 (62 mg, 49 %) and 2a (42 mg, 33 %).
6
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
0.36
1.62
5.77
5.74
5.61
5.58
5.55
5.49
5.46
7.92
7.84
7.67
7.65
7.63
7.45
7.45
7.43
7.27
7.23
7.16
CDCL3
1.0
0.9
0.8
O
0.7
Ar
(CO)3Cr
0.6
SiMe 3
0.5
1
0.4
0.3
0.2
0.1
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.40
7.0
9.18
77.62
77.00
76.38
7.5
2.07
107.66
101.08
98.76
93.25
92.59
8.0
3.95
231.82
8.5
3.03
120.93
1.00
145.77
134.27
131.07
129.05
128.72
0.0
1.0
0.9
O
Ar
0.8
(CO)3Cr
SiMe 3
0.7
1
0.6
0.5
0.4
0.3
0.2
0.1
0.0
200
150
100
50
0
7
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
0.43
1.57
2.78
2.76
2.71
2.68
2.63
2.46
7.48
7.46
7.40
7.37
7.35
7.32
7.27
6.80
6.75
6.49
6.43
5.81
5.71
5.69
5.58
5.28
5.25
5.19
5.15
5.14
5.09
5.07
CDCL3
1.0
0.9
0.8
OH
0.7
Ar
0.6
(CO)3Cr
0.5
SiMe3
2a
0.4
0.3
0.2
0.1
0.0
3.03
7.5
1.00 1.00
7.0
6.5
1.08
6.0
2.43
5.5
5.0
2.220.98
4.5
4.0
3.5
3.0
2.5
9.19
2.0
1.5
1.0
0.5
3.48
49.11
101.75
96.50
95.19
89.73
89.54
77.43
77.00
76.60
76.45
136.24
132.52
132.18
131.29
128.73
128.15
126.84
125.59
120.89
233.11
Chloroform-d
1.0
OH
0.9
0.8
Ar
(CO)3Cr
SiMe3
2a
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
200
150
100
50
0
8
3.48
49.08
95.37
89.67
89.48
101.91
132.49
132.03
131.27
128.73
128.15
126.84
121.07
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
1.0
0.9
0.8
OH
0.7
Ar
0.6
(CO)3Cr
SiMe3
2a
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
130
120
110
100
90
80
70
60
50
40
30
20
0.38
1.70
1.62
1.46
1.29
2.96
2.94
2.92
2.90
2.88
2.85
2.81
2.62
6.46
6.40
6.33
6.28
5.97
5.93
5.71
5.69
5.65
5.63
5.60
5.42
5.38
5.27
5.25
5.23
7.35
7.34
7.27
CDCL3
1.0
0.9
0.8
OH
0.7
Ar
(CO)3Cr
0.6
SiMe3
2b
0.5
0.4
0.3
0.2
0.1
0.0
5.04
7.5
1.00
7.0
6.5
1.03 2.07
6.0
5.5
2.11 1.00
5.0
4.5
4.0
3.5
3.0
2.5
9.02
2.0
1.5
1.0
0.5
10
0
9
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
3.26
46.91
77.43
77.00
76.57
75.38
101.51
98.76
94.55
90.70
89.54
136.18
135.57
131.97
130.04
128.67
128.00
126.56
126.20
122.08
233.44
Chloroform-d
OH
1.0
Ar
(CO)3Cr
0.9
SiMe3
2b
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
200
150
100
50
OH
Ar
(CO)3Cr
SiMe3
2b
0
10
3.26
46.78
90.67
89.45
94.67
101.62
135.44
131.90
129.89
128.63
127.96
126.53
122.23
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
1.0
0.5
0.0
-0.5
130
120
110
100
90
80
70
60
50
40
30
20
0.40
0.21
0.14
0.91
1.28
1.58
2.96
2.94
2.91
2.89
2.68
2.65
2.63
2.61
5.44
5.42
5.29
5.27
5.22
5.20
5.09
5.07
4.99
4.94
7.54
7.51
7.42
7.40
7.38
7.34
7.32
6.72
6.67
6.52
6.47
5.92
5.90
CDCl3
1.0
0.9
0.8
Ar
0.7
0.6
OSiMe3
(CO)3Cr
0.5
H
3
0.4
0.3
0.2
0.1
0.0
5.04
7.5
1.00
7.0
6.5
2.06
6.0
1.04 5.04
5.5
5.0
1.02 1.02
4.5
4.0
3.5
3.0
2.5
0.45 0.57
2.0
1.5
9.12
1.0
0.5
0.0
10
0
11
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
2.23
46.18
94.61
94.06
93.36
89.18
88.93
77.43
77.00
76.60
135.99
133.74
132.61
130.47
128.85
128.27
126.78
118.90
116.83
233.17
Chloroform-d
1.0
Ar
0.9
0.8
OSiMe3
(CO)3Cr
H
3
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
200
150
100
50
0
12
Ar
1.0
2.23
46.09
94.73
94.15
93.45
89.24
88.97
133.68
132.55
130.32
128.86
128.31
126.78
118.97
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
OSiMe3
(CO)3Cr
H
3
0.5
0.0
-0.5
130
120
110
100
90
80
70
60
50
40
30
20
0.66
0.50
1.58
2.72
2.69
2.65
2.62
2.58
2.55
2.51
2.48
5.11
5.08
5.07
4.99
5.55
5.52
5.48
5.35
5.32
5.19
5.16
7.48
7.48
7.44
7.34
7.28
7.27
6.82
6.75
6.40
6.33
5.67
CDCL3
1.0
0.9
0.8
Ar
0.7
0.6
O
(CO)3Cr
0.5
Si
H3C
CH3
4a
0.4
0.3
0.2
0.1
0.0
5.15
7.5
1.00
7.0
1.01
6.5
6.0
1.99
2.36
5.5
5.0
2.05
4.5
4.0
3.5
3.0
2.5
3.02
2.0
1.5
1.0
0.5
10
13
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
49.39
1.65
95.97
93.84
93.54
90.53
86.48
85.16
77.62
77.00
76.34
136.51
132.39
131.81
128.53
128.39
127.95
127.47
126.81
119.16
159.56
232.27
Chloroform-d
50
0
1.0
Ar
0.9
0.8
O
(CO)3Cr
Si
0.7
H3C
CH3
4a
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1.65
93.88
93.58
90.49
86.49
100
49.40
150
119.20
132.36
131.77
128.39
128.28
127.47
126.81
200
1.0
Ar
O
(CO)3Cr
Si
H3C
CH3
4a
0.5
0.0
130
120
110
100
90
80
70
60
50
40
30
20
10
0
14
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
0.45
0.68
2.91
2.88
2.86
2.84
2.79
2.77
2.75
2.72
6.56
6.50
6.25
6.20
6.01
5.99
5.93
5.48
5.46
5.45
5.31
5.29
5.29
5.25
5.20
5.17
7.32
7.31
7.27
CDCL3
1.0
Ar
0.9
0.8
O
(CO)3Cr
Si
0.7
H3C
CH3
0.6
4b
0.5
0.4
0.3
0.2
0.1
0.0
5.08
7.5
1.00 1.10 0.99
7.0
6.5
3.133.28
6.0
5.5
2.23
5.0
4.5
4.0
3.5
3.0
3.17
2.5
2.0
1.5
1.0
0.5
1.87
0.98
47.45
93.06
92.36
91.96
88.06
84.83
77.62
77.00
76.38
136.22
134.20
132.95
129.09
128.61
128.42
127.87
126.59
118.72
232.74
Chloroform-d
1.0
0.9
0.8
Ar
0.7
0.6
O
(CO)3Cr
Si
0.5
H3C
CH3
0.4
4b
0.3
0.2
0.1
0.0
200
150
100
50
0
15
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
0.18
1.26
1.56
3.52
3.48
3.44
3.41
3.38
3.17
3.12
3.11
3.09
3.07
2.99
2.48
2.45
2.41
5.81
5.77
5.76
5.74
5.72
5.69
5.49
5.47
5.46
5.45
5.08
5.03
4.98
7.35
7.34
7.30
7.27
7.26
7.22
7.19
7.17
CDCL3
1.0
0.9
O
Ph
0.8
(CO)3Cr
SiMe 3
2'
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
5.26
7.5
3.00
7.0
6.5
6.0
2.08
5.5
5.0
4.5
4.0
1.07 2.13
2.07
3.5
2.5
3.0
9.11
2.0
1.5
1.0
0.5
0.0
0.40
43.51
40.50
77.62
77.00
76.38
104.31
102.03
98.21
93.39
91.78
128.46
127.54
126.51
116.99
136.07
143.42
199.37
231.38
Chloroform-d
1.0
0.9
O
0.8
Ph
(CO)3Cr
0.7
SiMe 3
2'
0.6
0.5
0.4
0.3
0.2
0.1
0.0
200
150
100
50
0
16
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
H3C
1.0
0.9
0.59
0.41
1.46
1.65
5.53
5.50
5.47
5.44
5.27
5.25
5.24
5.22
5.19
7.27
CDCL3
CH3
O
(CO)3Cr
Si
0.8
CH3
H3C
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
2.02 2.03
7.0
6.5
6.0
5.5
3.05
5.0
4.5
4.0
3.5
3.0
2.5
2.0
3.04
1.5
1.0
0.5
H3C
1.0
0.9
2.01
0.91
34.47
30.17
96.67
93.87
93.25
91.23
86.74
81.48
77.00
131.25
232.89
cdcl3
CH3
O
(CO)3Cr
Si
0.8
H3C
CH3
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
200
150
100
50
0
17
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
1.54
0.21
5.64
5.61
5.42
5.39
5.36
5.23
5.20
5.17
7.27
CDCL3
6.38
9.37
1.0
0.9
H3C
0.8
(CO)3Cr
0.7
CH3
OSiMe3
H
0.6
0.5
0.4
0.3
0.2
0.1
0.0
2.00
7.0
6.5
6.0
5.5
2.06
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1.0
H3C
2.31
32.34
77.00
73.40
93.58
92.00
89.83
121.77
159.71
233.22
cdcl3
CH3
0.9
OSiMe3
(CO)3Cr
H
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
200
150
100
50
0
18
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
0.45
0.43
1.43
1.27
2.83
2.79
2.74
2.71
2.64
7.52
7.37
7.33
7.30
7.27
7.23
7.21
6.71
6.63
6.53
6.46
5.70
5.69
5.65
5.62
5.60
5.58
5.57
5.53
5.08
5.03
4.99
CDCL3
1.0
0.9
0.8
Ar
0.7
O
0.6
Si
H3C
0.5
CH3
0.4
0.3
0.2
0.1
0.0
9.17
7.5
2.00
7.0
6.5
0.99
6.0
5.5
2.05
5.0
2.10
4.5
4.0
3.5
3.0
2.5
6.00
2.0
1.5
1.0
0.5
19
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
1.97
2.22
7.46
7.42
7.37
7.34
7.30
7.29
7.22
CDCL3
1.0
Me
0.9
OH
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
9.78
7.5
1.04 3.00
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
Supplementary Material for Chemical Communications
This journal is © The Royal Society of Chemistry 2002
20