Reactions of sulfonyl chlorides with silyl enol ethers catalysed by a ruthenium(II) phosphine complex: Convenient synthesis of β-keto sulfones

Article abstract of DOI:10.1039/a604466b

The reactions of alkane- and arene-sulfonyl chlorides with silyl enol ethers in the presence of a ruthenium(II) phosphine complex are found to give β-keto sulfones in good to high yields.

Full text of DOI:10.1039/a604466b

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Reactions of sulfonyl chlorides with silyl enol ethers catalysed by a
ruthenium(II) phosphine complex: convenient synthesis of â-keto
sulfones
Nobumasa Kamigata,* Kumiko Udodaira and Toshio Shimizu
Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Minami-ohsawa,
Hachioji, Tokyo 192-03, Japan
The reactions of alkane- and arene-sulfonyl chlorides with silyl enol ethers in the presence of a
ruthenium(II) phosphine complex are found to give â-keto sulfones in good to high yields.
Table 1 Reaction of sulfonyl chlorides with silyl enol ethers in the
presence of a ruthenium() phosphine complex
Previously, we have reported that the ruthenium()-catalysed
reactions of alkane- and arene-sulfonyl chlorides with alkenes
afforded the corresponding 1:1 adducts in high yields.1 The
reaction is considered to proceed via a radical intermediate
confined in the coordination sphere of the ruthenium complex;
hence the radical is of reduced reactivity but of high selectivity
and thus gives a reaction product in high yield without any
accompanying side-products. Recently, Utimoto and co-workers
reported a radical reaction of perfluoroalkyl iodide with 1-
trimethylsilyloxycyclohexene mediated by triethylborane and
base which gives perfluoroalkylated trimethylsilyl enol ethers.2
These results prompted us to investigate the ruthenium()-
catalysed radical reactions of some sulfonyl chlorides with
various silyl enol ethers, which we found provided β-keto sul-
fones in good to high yields. The results are described herein.
R in 1
Ar in 2
Product
Yielda (%)
1a Me
2a Ph
2a Ph
2a Ph
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
3m
3n
3o
3p
3q
3r
86
86
91
55
69
54
60
70
71
50
79
57
68
75
76
65
67
63
1b p-Tol
1c C6F5
1a Me
1b p-Tol
1c C6F5
1a Me
1b p-Tol
1c C6F5
1a Me
1b p-Tol
1c C6F5
1a Me
1b p-Tol
1c C6F5
1a Me
1b p-Tol
1c C6F5
2b p-MeOC6H4
2b p-MeOC6H4
2b p-MeOC6H4
2c p-MeC6H4
2c p-MeC6H4
2c p-MeC6H4
2d p-FC6H4
2d p-FC6H4
2d p-FC6H4
2e p-ClC6H4
2e p-ClC6H4
2e p-ClC6H4
2f p-NO2C6H4
2f p-NO2C6H4
2f p-NO2C6H4
Results and discussion
A solution of methanesulfonyl chloride 1a (2.0 mmol), 1-
trimethylsilyloxy-1-phenylethene 2a (2.0 mmol) and dichloro-
tris(triphenylphosphine)ruthenium() (0.02 mmol) in benzene
(4.0 cm3) when degassed and heated at 120 ЊC for 7 h, reacted
smoothly to afford methyl phenacyl sulfone 3a in 86% isolated
yield (Scheme 1). No 1:1 adduct such as 1-chloro-2-methyl-
sulfonyl-1-trimethylsilyloxy-1-phenylethane was found in the
reaction products. There was no reaction in the absence of the
ruthenium() catalyst, unchanged 1a and 2a being recovered.
The reaction is, therefore, truly a catalytic one.
a
Isolated yield.
to investigate the scope and limitation of this reaction for the
synthesis of β-keto sulfones (Scheme 2). The results are sum-
marized in Table 1.
O
OSiMe3
i
ArC CH2
RSO2Cl
+
ArCCH2SO2R + Me3SiCl
O
1
2
3
OSiMe3
i
MeSO2Cl
+
PhCCH2SO2Me + Me3SiCl
PhC CH2
a R = Me
b R = p-Tol
c R = C6F5
1a
2a
3a
Scheme 1 Reagent and conditions: i, [RuCl2(PPh3)3], C6H6, 120 ЊC, 7 h
Scheme 2 Reagent and conditions: i, [RuCl2(PPh3)3], C6H6, 120 ЊC, 7 h
Product 3a can be regarded not only as an α-substituted
methylsulfonyl derivative of acetophenone, which is a starting
material of silyl enol ether 2a, but also as an active methylene
compound containing carbonyl and sulfonyl groups. The pres-
ent reaction seems to be a convenient and an excellent method
for the synthesis of β-keto sulfones since it is known that the
reactions of a metal (sodium or potassium) enolate of 3,3-
dimethylbutanone with benzenesulfonyl chloride gives 1-
chloro-3,3-dimethylbutanone and with benzenesulfonyl fluor-
ide affords a mixture of 1-phenylsulfonyl-3,3-dimethylbutanone
and 3,3-dimethyl-2-phenylsulfonyloxybut-1-ene.3 Since active
methylene compounds are important intermediates for reac-
tions such as Michael addition, a number of sulfonyl chlorides
were allowed to react with a variety of silyl enol ethers in order
As shown in Table 1, the ruthenium()-catalysed reactions of
toluene-p-sulfonyl chloride 1b and pentafluorobenzenesulfonyl
chloride 1c with 2a under similar conditions afforded the
corresponding β-keto sulfones 3b and 3c, respectively, in
high yields. Similarly, the reactions of the sulfonyl chlorides
1a–c with 1-trimethylsilyloxy-1-(4Ј-methoxyphenyl)ethene 2b,
1-trimethylsilyloxy-1-(4Ј-tolyl)ethene 2c, 1-trimethylsilyloxy-
1-(4Ј-fluorophenyl)ethene 2d, 1-trimethylsilyloxy-1-(4Ј-chloro-
phenyl)ethene 2e and 1-trimethylsilyloxy-1-(4Ј-nitrophenyl)-
ethene 2f in the presence of the ruthenium() catalyst gave
the corresponding β-keto sulfones 3d–r in good to high
yields irrespective of the substituent (an electron-donating or
J. Chem. Soc., Perkin Trans. 1, 1997
783

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-withdrawing group) on the aromatic ring of silyl enol ether.
Thus, the present ruthenium()-catalysed reactions of sulfonyl
chloride with silyl enol ether were found to be a convenient and
an excellent method for the synthesis of β-keto sulfones.
A mechanism for the ruthenium()-catalysed reactions of
sulfonyl chloride 1 with silyl enol ethers 2 is given in Scheme 3.
O
OSiMe3
i
ButCCH2SO2C6F5
C6F5SO2Cl
+
ButC CH2
2g
1c
3s
O
O
OSiMe3
i
ArSO2Cl
+
Me(CH2)4CCH2SO2Ar
RuII
Me3SiCl + ArCCH2SO2R
RSO2Cl
Me(CH2)4C CH2
1
3
1b Ar = p-Tol
1c Ar = C6F5
2h
RuIII–Cl
Me3SiO
Ar
Scheme 5 Reagent and conditions: i, [RuCl2(PPh3)3], C6H6, 120 ЊC, 7 h
–
•
[RSO2Cl]• + RuIII
CH2SO2R
C
4
1-trimethylsilyloxy-2-(p-tolylsulfonyl)ethene (R = tosyl) by
base-catalysed β-elimination reaction competing with the
elimination of trimethylchlorosilane to give 3. However, since
no 1-trimethylsilyloxy-1-phenyl-2-(p-tolylsulfonyl)ethene was
obtained in the ruthenium()-catalysed reaction of 1b with 2a
in the presence of 2,6-di-tert-butylpyridine, 3b and trimethyl-
silane being formed instead, path b is the more plausible
mechanism.
6
RSO2•
5
RuIII Cl
OSiMe3
ArC CH2
2
Scheme 3
The ruthenium()-catalysed reactions of sulfonyl chloride
with 1-alkyl-1-trimethylsilyloxyethene were investigated under
similar conditions. The ruthenium()-catalysed reaction of 1c
with 3,3-dimethyl-2-trimethylsilyloxybut-1-ene 2g gave 1-penta-
fluorophenylsulfonyl-3,3-dimethylbutan-2-one 3s in low yield
(12%) contrary to our expectation. Moreover, only a trace
amount of the corresponding β-keto sulfone was obtained in
the reactions of 1b and 1c with 2 trimethylsilyloxyhept-1-ene 2h
in the presence of a ruthenium() complex. These results sug-
gest that the carbon radical formed by the addition of a sulfonyl
radical to the carbon–carbon double-bond of the silyl enol
ether 2g or 2h is unstable since the carbon radical cannot be
resonance stabilized with any neighbouring substituent. Thus,
it is considered that the addition of a sulfonyl radical to the
carbon–carbon double bond of silyl enol ethers possessing only
an alkyl group such as 2h is a difficult process. This may be a
limitation of the ruthenium()-catalysed reaction.
The redox-transfer reaction between the sulfonyl chloride 1 and
the ruthenium() catalyst affords the anion radical 4 of com-
pound 1, which is cleaved homolytically to give the sulfonyl rad-
ical 5 and RuIII᎐Cl. The sulfonyl radical 5 adds to the carbon–
carbon double bond of the silyl enol ether 2 to give the carbon
radical 6 which affords the β-keto sulfone 3 and trimethyl-
chlorosilane, the ruthenium() catalyst being regenerated. The
radicals 5 and 6 are considered to be confined in the coordin-
ation sphere of the ruthenium catalyst.4
Two pathways are plausible for the formation of the β-keto
sulfone and trimethylchlorosilane from the radical intermediate
6 (see Scheme 4). One is abstraction of the chlorine which is
OSiMe3
Me3Si Cl
ArCCH2SO2R
O
C
CH2SO2R
Cl
7
In conclusion, we have found that the reactions of sulfonyl
chlorides with silyl enol ethers, prepared from acetophenone
derivatives, in the presence of a ruthenium() complex gave the
corresponding β-keto sulfones in good to high yield. This is
therefore an excellent method for conveniently synthesising
active methylene compounds.
Ar
Path a
–Ru(II)
O
RuIII–Cl
•
ArCCH2SO2R
Me3SiO
Ar
3
+
CH2SO2R
C
6
Me3SiCl
Path b
–Ru(II)
Experimental
Me3Si
Cl
RuIII
O
Mps were determined on a Yamato MP21 apparatus and are
uncorrected. IR Spectra were determined on a JASCO A-100
IR spectrophotometer with samples as either neat liquids or
C
Ar
CH2SO2R
1
KBr disks. H and 13C NMR spectra were determined on a
Scheme 4
JEOL JNM-EX 400 FT NMR spectrometer at 400 and 100
MHz, respectively, using Me4Si as an internal standard. 19F
NMR Spectra were taken on a JEOL JNM-EX 400 FT NMR
spectrometer at 376 MHz using CFCl3 as an external standard;
J values are given in Hz. Mass spectra were measured on a
JEOL JMS-AX 500 spectrometer by electron impact (EI) at 70
eV. Gas-liquid chromatography (GLC) were performed using a
Hitachi G-3000 gas chromatograph with OV-1 (10%) 25 m
capillary column. Gel-permeation chromatography (GPC) was
performed using a JAI LC-08 and JAI LC-908 liquid chro-
matograph with two JAIGEL-1H columns (20 × 600 mm)
with chloroform as eluent.
All solvents were distilled and stored under nitrogen.
p-Methoxyacetophenone and p-fluoroacetophenone were from
Wako Chemicals, p-methylacetophenone, p-nitroacetophenone
and 3,3-dimethylbutan-2-one were from Nakarai Chemicals,
heptan-2-one and p-chloroacetophenone were from Tokyo
Kasei Chemicals and trimethylchlorosilane was obtained from
bonded to the ruthenium by the carbon radical to give a 1:1
adduct 7 and ruthenium() complex. Adduct 7 will rapidly
degrade to the β-keto sulfone 3 and trimethylchlorosilane prob-
ably via a four-centre type reaction, the affinity between silicon
and chlorine being strong and the reaction occurring very easily
(path a). The other mechanism is direct reaction between silicon
and chlorine atoms in the radical intermediate 6 via a five-
membered ring (path b); since 6 is thought to be confined to the
coordination sphere of the ruthenium complex, such a transi-
tion state will easily form. The fact that no adduct 7 (Ar =
Ph, R = p-tolyl) was found in the reaction mixture in the
ruthenium()-catalysed reaction of 1b with 2a suggests that
either adduct 7 will eliminate trimethylchlorosilane very rapidly
under the reaction conditions (path a) or 3 is formed directly
from 6 via the 5-centre transition state (path b).
If we suppose that 7 is initially formed when 1b and 2a react
in the presence of a base, this adduct is expected to give 1-aryl-
784
J. Chem. Soc., Perkin Trans. 1, 1997

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the Shinetsu Chemical Industry. All were used without further
purification for the preparation of the corresponding silyl enol
ethers. 1-Trimethylsilyloxy-1-phenylethene 2a from Aldrich
Chemicals was used without further purification. Methanesul-
fonyl chloride from Wako Chemicals and pentafluorobenzene-
sulfonyl chloride from Hydrus Chemicals were used without
further purification. Toluene-p-sulfonyl chloride from Wako
Chemicals was recrystallized from hexane prior to use. Dichloro-
tris(triphenylphosphine)ruthenium() was prepared by the
method described in the literature, mp 123 ЊC.5
129.0, 129.2, 135.0, 135.1 and 187.8; δF (376 MHz, CDCl3)
135.88–136.01 (2 F, m), 142.84 (1 F, tt, J 21.3 and 7.8) and
158.27–158.43 (2 F, m); m/z 350 (M+), 287, 183 and 167 (Found:
C, 48.00; H, 1.81. Calc. for C14H7F5O3S: C, 48.01; H, 2.01%).
4-Methoxyphenacyl methyl sulfone 3d. Colourless needles;
mp 136.0–136.9 ЊC (from CH2Cl2–hexane; lit.,10 136–137 ЊC);
vmax(KBr)/cmϪ1 3150, 2960, 1670, 1600, 1330, 1310, 1270, 1190
and 1160; δH (400 MHz, CDCl3) 3.13 (3 H, s), 3.90 (3 H, s),
4.54 (2 H, s), 6.98 (2 H, d, J 8.8) and 7.98 (2 H, d, J 8.8);
δC(100 MHz, CDCl3) 41.7, 55.6, 61.1, 114.2, 128.6, 131.9, 164.8
and 187.3; m/z 229 (M+ + 1), 150, 136 and 107.
General procedures for the preparation of silyl enol ethers6 2b–f
To a solution of aryl methyl ketone (80 mmol) in DMF (32 ml)
under nitrogen was added triethylamine (19.5 g, 192 mmol)
followed by trimethylchlorosilane (10.4 g, 96 mmol). After the
solution had been refluxed and stirred for 48 h, it was extracted
with pentane (80 cm 3) and the extract was washed with a satur-
ated aqueous potassium hydrogen carbonate ( × 3), water (80
cm 3 × 3), 1.5  hydrochloric acid (80 cm 3 × 2), water (80 cm 3),
saturated aqueous potassium hydrogen carbonate (80 cm 3 × 2),
water (80 cm 3 × 2) and brine (80 cm 3). The solvent then evapor-
ated under reduced pressure and the residual oily silyl enol
ether was distilled. Yields and boiling points of silyl enol ethers
are as follows: 1-trimethylsilyloxy-1-(4Ј-methoxyphenyl)ethene
2b (50%), bp 88 ЊC/0.50 mmHg; 1-trimethylsilyloxy-1-(4Ј-
tolyl)ethene 2c (67%), bp 59–60 ЊC/0.45 mmHg; 1-trimethyl-
silyloxy-1-(4Ј-fluorophenyl)ethene 2d (59%), bp 43–46 ЊC/0.50
mmHg; 1-trimethylsilyloxy-1-(4Ј-chlorophenyl)ethene 2e (42%),
bp 54–56 ЊC/0.8 mmHg; 1-trimethylsilyloxy-1-(4Ј-nitrophenyl)-
ethene 2f (34%), bp 95–97 ЊC/0.45 mmHg.
4-Methoxyphenacyl 4Ј-tolyl sulfone11 3e. Colourless needles;
mp 124.0–124.4 ЊC (from CH2Cl2–hexane); vmax(KBr)/cmϪ1
2950, 2900, 1675, 1600, 1570, 1310, 1260, 1180 and 1140; δH (400
MHz, CDCl3) 2.44 (3 H, s), 3.89 (3 H, s), 4.66 (2 H, s), 6.95
(2 H, d, J 8.8), 7.33 (2 H, d, J 8.1), 7.75 (2 H, d, J 8.1) and 7.94
(2 H, d, J 8.8); δC(100 MHz, CDCl3) 22.0, 55.9, 63.9, 114.3,
128.9, 129.2, 130.1, 132.2, 136.0, 145.6, 164.8 and 186.6;
m/z 304 (M+), 240 and 135.
4-Methoxyphenacyl pentafluorophenyl sulfone 3f. Colourless
needles; mp 112.9–113.3 ЊC (from CH2Cl2–hexane); vmax(KBr)/
cmϪ1 3020, 2980, 2900, 1690, 1600, 1500, 1340, 1260 and 1170;
δH (400 MHz, CDCl3) 3.91 (3 H, s), 4.86 (2 H, s), 6.99 (2 H, d, J
6.8) and 7.92 (2 H, d, J 6.8); δC(100 MHz, CDCl3) 55.7, 63.1,
114.4, 128.2, 131.6, 165.1 and 185.8; δF (376 MHz, CDCl3)
136.67–136.80 (2 F, m), 143.77 (1 F, tt, J 21.4 and 7.5) and
159.11–159.28 (2 F, m); m/z 381 (M+ + 1), 317, 231, 167 and 134
(Found: C, 47.60; H, 2.30. Calc. for C15H9F5O4S: C, 47.38; H,
2.39%).
Methyl 4-methylphenacyl sulfone 3g. Colourless needles; mp
114.0–114.7 ЊC (from CH2Cl2–hexane; lit.,12 114–117 ЊC); vmax
-
Preparation of the silyl enol ethers 2g and 2h
(KBr)/cmϪ1 3000, 2940, 1660, 1600, 1420, 1320 and 1160;
δH (400 MHz, CDCl3) 2.44 (3 H, s), 3.14 (3 H, s), 4.58 (2 H, s),
7.32 (2 H, d, J 8.3) and 7.90 (2 H, d, J 8.3); δC(100 MHz,
CDCl3) 21.8, 41.7, 61.2, 129.4, 129.7, 133.1, 146.0 and 188.7;
m/z 212 (M+), 119 and 91.
3,3-Dimethyl-2-trimethylsilyloxybut-1-ene2gwasprepared from
3,3-dimethylbutan-2-one by the method reported in the liter-
ature;6 yield 33%. 2-Trimethylsilyloxyhept-1-ene2hwasprepared
according to the literature by treating heptan-2-one with LDA
in THF at Ϫ 78 ЊC and then adding trimethylchlorosilane to
the resultant lithium enolate of heptan-2-one.7
4-Methylphenacyl 4Ј-tolyl sulfone 3h. Colourless needles; mp
112.1–112.4 ЊC (from CH2Cl2–hexane; lit.,9 112 ЊC); vmax(KBr)/
cmϪ1 2960, 1670, 1610, 1310 and 1150; δH (400 MHz, CDCl3)
2.33 (3 H, s), 2.43 (3 H, s), 4.68 (2 H, s), 7.28 (2 H, d, J 8.3), 7.33
(2 H, d, J 8.3), 7.75 (2 H, d, J 8.3) and 7.85 (2 H, d, J 8.3); δC(100
MHz, CDCl3) 22.0, 22.1, 63.9, 128.9, 129.80, 129.83, 130.1,
133.7, 136.1, 145.6, 145.8 and 187.9; m/z 288 (M+), 225 and 120.
4-Methylphenacyl pentafluorophenyl sulfone 3i. Colourless
needles; mp 151.8–152.1 ЊC (from CH2Cl2–hexane); vmax(KBr)/
cmϪ1 2980, 2910, 1690, 1610, 1500, 1350 and 1150; δH (400
MHz, CDCl3) 2.45 (3 H, s), 4.89 (2 H, s), 7.32 (2 H, d, J 8.3) and
7.83 (2 H, d, J 8.3); δC(100 MHz, CDCl3) 22.1, 63.5, 129.5,
130.2, 133.0, 146.8 and 187.5; δF (376 MHz, CDCl3) 136.66–
136.79 (2 F, m), 144.0 (1 F, tt, J 22.0 and 7.1) and 159.03–159.22
(2 F, m); m/z 364 (M+), 344, 300, 168 and 119 (Found: C, 49.27;
H, 2.29. Calc. for C15H9F5O3S: C, 49.46; H, 2.49%).
4-Fluorophenacyl methyl sulfone 3j. Colourless needles; mp
112.5–113.4 ЊC (from CH2Cl2–hexane); vmax(KBr)/cmϪ1 3020,
1670, 1590, 1420, 1300, 1230 and 1140; δH (400 MHz, CDCl3)
3.15 (3 H, s), 4.57 (2 H, s), 7.21 (2 H, dd, J 7.8 and 7.8) and 8.06
(2 H, dd, J 7.8 and 5.4); δC(100 MHz, CDCl3) 41.7, 61.5, 116.3,
132.1, 132.3, 166.7 and 187.6; m/z 216 (M+), 201, 138 and 96;
δF (376 MHz, CDCl3) 102.80–102.88 (1 F, m) (Found: C, 50.04;
H, 4.11. Calc. for C9H9FO3S: C, 49.99; H, 4.20%).
4-Fluorophenacyl 4Ј-tolyl sulfone 3k. Colourless needles; mp
134.0–134.4 ЊC (from CH2Cl2–hexane); vmax(KBr)/cmϪ1 3010,
1680, 1600, 1420, 1290, 1230 and 1150; δH (400 MHz, CDCl3)
2.45 (3 H, s), 4.68 (2 H, s), 7.16 (2 H, dd, J 8.6 and 8.6), 7.34
(2 H, d, J 8.3), 7.75 (2 H, d, J 8.3) and 8.01 (2 H, dd, J 8.6 and
5.4); δC(100 MHz, CDCl3) 21.7, 63.7, 116.1, 128.5, 129.9, 131.5,
132.2, 135.6, 145.5, 166.4 and 186.5; δF (376 MHz, CDCl3)
103.52–103.60 (1 F, m); m/z 292 (M+), 226, 155, 123 and 95
(Found: C, 61.51; H, 4.35. Calc. for C15H13FO3S: C, 61.63; H,
4.48%).
General procedure for the reaction of sulfonyl chlorides with silyl
enol ethers
A solution containing the sulfonyl chloride 1 (2.0 mmol), silyl
enol ether 2 (2.0 mmol) and dichlorotris(triphenylphosphine)-
ruthenium() (0.02 mmol) in dry benzene (4.0 cm3) was
degassed by a freeze–pump–thaw cycle, sealed in an ampoule
and heated at 120 ЊC for 7 h.The reaction mixture was subjected
to column chromatography on Merck 7734 silica gel 60 with
hexane–ethyl acetate (5:1) as eluent. The product was further
purified by recrystallization from dichloromethane–hexane and
identified by IR, NMR and MS spectroscopy. The physical and
spectral data for the compounds obtained are as follows.
Methyl phenacyl sulfone 3a. Colourless needles; mp 106.7–
107.0 ЊC (from CH2Cl2–hexane; lit.,8 106–107 ЊC); vmax(KBr)/
cmϪ1 3000, 2950, 1680, 1300 and 1150; δH (400 MHz, CDCl3)
3.16 (3 H, s), 4.61 (2 H, s), 7.54 (2 H, dd, J 8.0 and 7.4), 7.67 (1
H, t, J 7.4) and 8.01 (2 H, d, J 8.0); δC(100 MHz, CDCl3) 41.8,
61.3, 129.1, 129.3, 134.8, 135.6 and 189.2; m/z 198 (M+), 105
and 77.
Phenacyl 4Ј-tolyl sulfone 3b. Colourless needles; mp 106.4–
106.8 ЊC (from CH2Cl2–hexane; lit.,9 108 ЊC); vmax(KBr)/cmϪ1
3000, 1680, 1320 and 1150; δH (400 MHz, CDCl3) 2.44 (3 H, s),
4.71 (2 H, s), 7.33 (2 H, d, J 8.3), 7.48 (1 H, dd, J 8.3 and 7.3),
7.61 (1 H, t, J 7.3), 7.76 (2 H, d, J 8.3) and 7.94 (2 H, d, J 8.3);
δC(100 MHz, CDCl3) 21.6, 63.5, 128.5, 128.8, 129.3, 129.8,
134.3, 135.7, 136.0, 145.3 and 188.1; m/z 274 (M+) and 211.
Pentafluorophenyl phenacyl sulfone 3c. Colourless needles; mp
141.4–142.5 ЊC (from CH2Cl2–hexane); vmax(KBr)/cmϪ1 3000,
2950, 1700, 1490, 1350, 1270, 1160 and 990; δH (400 MHz,
CDCl3) 4.29 (2 H, s), 7.52 (2 H, dd, J 8.3 and 7.3), 7.68 (1 H,
t, J 7.3) and 7.93 (2 H, d, J 8.3); δC(100 MHz, CDCl3) 63.1,
J. Chem. Soc., Perkin Trans. 1, 1997
785

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4-Fluorophenacyl pentafluorophenyl sulfone 3l. Colourless
needles; mp 127.4–128.0 ЊC (from CH2Cl2–hexane); vmax(KBr)/
cmϪ1 2950, 1700, 1600, 1500, 1320, 1220 and 1160; δH (400
MHz, CDCl3) 4.89 (2 H, s), 7.21 (2 H, dd, J 8.6 and 8.6) and
7.99 (2 H, dd, J 8.6 and 5.4); δC(100 MHz, CDCl3) 63.2, 116.5,
131.6, 132.0, 166.9 and 186.2; δF (376 MHz, CDCl3) 101.91–
101.97 (1 F, m), 136.55–136.68 (2 F, m), 143.19 (1 F, tt, J 21.1
and 8.2) and 158.82–158.99 (2 F, m); m/z 368 (M+), 304, 168 and
123 (Found: C, 45.64; H, 1.46. Calc. for C14H6F6O3S: C, 45.66;
H, 1.64%).
4-Chlorophenacyl methyl sulfone 3m. Colourless needles; mp
142.3–143.1 ЊC (from CH2Cl2–hexane; lit.,11 147–148 ЊC);
vmax(KBr)/cmϪ1 3050, 2950, 1680, 1590, 1410, 1300 and 1120;
δH (400 MHz, CDCl3) 3.14 (3 H, s), 4.57 (2 H, s), 7.50 (2 H, d, J
8.8) and 7.95 (2 H, d, J 8.8); δC(100 MHz, CDCl3) 41.7, 61.3,
129.4, 130.6, 133.9, 141.5 and 188.0; m/z 232 (M+), 154, 141 and
111.
cmϪ1 2950, 1700, 1530, 1500, 1350, 1170, 1140 and 950;
δH (400 MHz, CDCl3) 4.95 (2 H, s), 8.16 (2 H, d, J 8.8) and 8.40
(2 H, d, J 8.8); δC(100 MHz, CDCl3) 63.2, 124.3, 130.4, 139.6,
150.7 and 187.2; δF (376 MHz, CDCl3) 136.29–136.43 (2 F, m),
142.26 (1 F, tt, J 21.0 and 8.3) and 158.33–158.50 (2 F, m); m/z
395 (M+), 331, 167 and 151 (Found: C, 42.92; H, 1.40; N, 3.55.
Calc. for C14H6NF5O5S: C, 42.54; H, 1.53; N, 3.54%).
1-Pentafluorophenylsulfonyl-3,3-dimethylbutanone 3s. Colour-
less plates; mp 137.9–138.4 ЊC (from CH2Cl2–hexane); vmax
-
(KBr)/cmϪ1 3000, 1720, 1500, 1360, 1310, 1170 and 1100;
δH (400 MHz, CDCl3) 1.19 (9 H, s) and 4.49 (2 H, s); δC(100
MHz, CDCl3) 25.4, 45.5, 61.3 and 203.5; δF (376 MHz, CDCl3)
137.36–137.49 (2 F, m), 144.18 (1 F, tt, J 21.8 and 7.1) and
159.26–159.36 (2 F, m); m/z 331 (M+ + 1), 266, 231 and 99
(Found: C, 43.64; H, 3.36. Calc. for C12H11F5O3S: C, 43.46; H,
3.20%).
4-Chlorophenacyl 4Ј-tolyl sulfone 3n. Colourless needles; mp
134.4–134.9 ЊC (from CH2Cl2–hexane; lit.,9 137 ЊC); vmax(KBr)/
cmϪ1 3000, 1680, 1590, 1310 and 1150; δH (400 MHz, CDCl3)
2.45 (3 H, s), 4.58 (2 H, s), 7.34 (2 H, d, J 8.3), 7.46 (2 H, d, J
8.3), 7.74 (2 H, d, J 8.3) and 7.91 (2 H, d, J 8.3); δC(100 MHz,
CDCl3) 22.0, 64.1, 128.9, 129.5, 130.2, 131.1, 134.4, 135.9,
141.4, 145.9 and 187.3; m/z 308 (M+), 244, 139 and 91.
4-Chlorophenacyl pentafluorophenyl sulfone 3o. Colourless
needles; mp 152.5–153.1 ЊC (from CH2Cl2–hexane); vmax(KBr)/
cmϪ1 3000, 2950, 1690, 1590, 1500, 1360, 1310, 1220, 1160 and
950; δH (400 MHz, CDCl3) 4.88 (2 H, s), 7.52 (2 H, d, J 8.8) and
7.89 (2 H, d, J 8.8); δC(100 MHz, CDCl3) 63.1, 129.6, 130.4,
133.4, 141.9 and 186.6; δF (376 MHz, CDCl3) 136.50–136.64 (2
F, m), 143.06 (1 F, tt, J 22.4 and 7.5) and 158.74–158.91 (2 F,
m); m/z 384 (M+), 320, 141 and 111 (Found: C, 43.67; H, 1.47.
Calc. for C14H6F5ClO3S: C, 43.71; H, 1.57%).
References
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Sulfur, 1984, 19, 199; N. Kamigata, J. Ozaki and M. Kobayashi,
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2 K. Miura, M. Taniguchi, K. Nozaki, K. Ohshima and K. Utimoto,
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4 M. Kameyama, N. Kamigata and M. Kobayashi, J. Org. Chem.,
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5 T. A. Stephenson and G. Wilkinson, J. Inorg. Nucl. Chem., 1966, 28,
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6 H. O. House, L. J. Csuba and H. D. Olmstead, J. Org. Chem., 1969,
34, 2324.
Methyl 4-nitrophenacyl sulfone13 3p. Pale yellow needles; mp
148.9–149.4 ЊC (from CH2Cl2–hexane); vmax(KBr)/cmϪ1) 3100,
3030, 2950, 1680, 1600, 1520, 1310, 1150 and 1120; δH (400
MHz, CDCl3) 3.17 (3 H, s), 4.65 (2 H, s), 7.90 (2 H, d, J 7.1) and
8.20 (2 H, d, J 7.1); δC(100 MHz, CDCl3) 41.8, 61.7, 124.2,
130.5, 139.9, 150.8 and 188.2; m/z 244 (M+ + 1), 227, 180, 164
and 151.
7 E. J. Corey and A. W. Gross, Tetrahedron Lett., 1984, 25, 495.
8 H. O. Becker and C. A. Rusell, J. Org. Chem., 1963, 28, 1896.
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1713.
10 C. A. Ibara, R. C. Rodriquez, M. C. Monreal, F. J. Navarro and
J. M. Tesore, J. Org. Chem., 1983, 54, 5620.
11 R. A. Harris, T. J. Mason and G. T. Hannah, J. Chem. Res., 1990,
(S), 218.
4-Nitrophenacyl 4Ј-tolyl sulfone 3q. Pale yellow needles; mp
142.2–142.9 ЊC (from CH2Cl2–hexane; lit.,8 145 ЊC); vmax(KBr)/
cmϪ1 3000, 1690, 1600, 1530, 1350, 1310 and 1150; δH (400 MHz,
CDCl3) 2.46 (3 H, s), 4.77 (2 H, s), 7.37 (2 H, d, J 8.1), 7.75 (2 H,
d, J 8.1), 8.15 (2 H, d, J 9.0) and 8.33 (2 H, d, J 9.0); δC(100 MHz,
CDCl3) 21.4, 64.0, 123.9, 128.5, 130.0, 130.5, 135.3, 139.9, 145.9,
150.7 and 187.0; m/z 319 (M+), 255, 240, 150 and 91.
12 L. Pavlickova, B. Koutek, J. Velek and M. Soucek, Collect. Czech.
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13 G. Distefano, M. D. Colle, V. Bertolasi, P. R. Olivato, E. Bonfada
and M. G. Mondino, J. Chem. Soc., Perkin Trans. 2, 1991, 1195.
Paper 6/04466B
Received 26th June 1996
Accepted 28th October 1996
4-Nitrophenacyl pentafluorophenyl sulfone 3r. Pale yellow
needles; mp 184.3–185.0 ЊC (from CH2Cl2–hexane); vmax(KBr)/
786
J. Chem. Soc., Perkin Trans. 1, 1997