A new method for the synthesis of aromatic sulfurpentafluorides and studies of the stability of the sulfurpentafluoride group in common synthetic transformations

Article abstract of DOI:10.1016/S0040-4020(00)00184-8

A new synthesis of aromatic sulfurpentafluoride compounds is described. Subsequent elaboration of the aromatic rings in the presence of the sulfurpentafluoride group is also discussed for a variety of common synthetic methods. This paper also describes ab initio electronic structure calculations of 3- and 4-aminophenylsulfurpentafluoride, compared with 3- and 4-aminobenzotrifluoride, and presents X-ray crystal structures of two aromatic sulfurpentafluoride derivatives. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0040-4020(00)00184-8

TETRAHEDRON
Pergamon
Tetrahedron 56 (2000) 3399±3408
A New Method for the Synthesis of Aromatic Sulfurpenta¯uorides
and Studies of the Stability of the Sulfurpenta¯uoride Group in
Common Synthetic Transformations
b
Roy D. Bowden, Paul J. Comina, Martin P. Greenhall, Benson M. Kariuki, Amanda Loveday
a
b
a
a
a,
*
and Douglas Philp
a
School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
b
F2 Chemicals Ltd, Lea Lane, Lea Town, Preston, Lancashire, PR4 0RZ, UK
Received 14 January 2000; accepted 24 February 2000
AbstractÐA new synthesis of aromatic sulfurpenta¯uoride compounds is described. Subsequent elaboration of the aromatic rings in the
presence of the sulfurpenta¯uoride group is also discussed for a variety of common synthetic methods. This paper also describes ab initio
electronic structure calculations of 3- and 4-aminophenylsulfurpenta¯uoride, compared with 3- and 4-aminobenzotri¯uoride, and presents
X-ray crystal structures of two aromatic sulfurpenta¯uoride derivatives. q 2000 Elsevier Science Ltd. All rights reserved.
8
Organo¯uorine compounds, and in particular ¯uorinated
aromatic compounds such as benzotri¯uoride and its deriva-
aromatic sulfurpenta¯uorides has been described including
reductions, diazotisations and hydrolyses. Other characteri-
1
±4
9±15
16,17
tives, are well established in synthetic organic chemistry
and have found wide application as dye-stuffs, ¯uoro-
plastics, anaesthetics and as chemotherapeutic treatments,
amongst others. Less well known in organo¯uorine
chemistry, however, is the use of the sulfurpenta¯uoride
group, and in particular the use of aromatic sulfurpenta¯uor-
sation studies
and properties
(such as insecticidal
activity) also point to the potential synthetic utility and
stability of these materials.
1
8
Here, we present a new method for the direct preparation
of aromatic sulfurpenta¯uorides from readily available
starting materials. The stability of the sulfurpenta¯uoride
group to several common synthetic transformations is also
described, as well as the attempted hydrolysis of the sulfur-
penta¯uoride group under basic and acidic conditions. The
®rst two crystal structures of aromatic sulfurpenta¯uorides
and some ab initio electronic structure calculations on
(aminophenyl)sulfurpenta¯uorides are also reported.
5
,6
ide compounds. Despite having been ®rst prepared forty
years ago little development of aromatic sulfurpenta¯uoride
chemistry has been reported. Probably one of the key
stumbling blocks to the exploration of aromatic sulfurpenta-
1
9
¯
uoride chemistry has been the lack of good synthetic routes
available for the preparation of these materials. The only
reported method, described by Sheppard, and subsequently
modi®ed by Zeneca, utilises silver ¯uoride as the ¯uori-
7
nating reagent, but suffers, however, from the disadvantages
that silver ¯uoride is rather expensive and that the yields of
the desired sulfurpenta¯uoride compounds are generally
low (,20%). Despite this, some synthetic work utilising
Our strategy for the preparation of aromatic sulfurpenta-
¯uorides involved a direct ¯uorination process using F gas.
Three readily available starting materialsÐthe thiophenols
1, aromatic methyl thioethers 2 and disul®des 3 (Fig. 1)Ð
2
Figure 1. Potential starting materials 1±3 for the preparation of nitrophenyl sulfurpenta¯uorides 4.
Keywords: sulfur halogen compounds; ¯uorine and compounds; coupling reactions; X-ray crystallography.
*
Corresponding author. E-mail: d.philp@bham.ac.uk
0040±4020/00/$ - see front matter q 2000 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(00)00184-8

3
400
R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
Scheme 1. The synthesis and some reactions of 3-nitrophenylsulfurpenta¯uoride 4a and 4-nitrophenylsulfurpenta¯uoride 4b.
were identi®ed as being suitable for study and their reac-
tivities were investigated.
prevents complete ¯uorination at the adjacent SF site.
3
These results are consistent with earlier work by Kharasch
who demonstrated that ¯uorination of bis(2,4-dinitro-
2
1
In a typical ¯uorination procedure, the substrate was
dissolved in anhydrous acetonitrile at a temperature of
between 28 and 248C. A steady stream of a mixture of
F and N gas (10% v/v F ) was then passed through the
phenyl)disul®de using F in anhydrous HF afforded only
2
the sulfurtri¯uorides in high yield. We have also ¯uorinated
successfully other aromatic disul®des, using the above
procedure, to give several substituted aromatic sulfurpenta-
¯uorides, such as tri¯uoromethylphenyl sulfurpenta¯uoride.
The procedure described above (see also Scheme 1) repre-
sents a signi®cant improvement on Sheppard's method for
the preparation of aromatic sulfurpenta¯uoride compounds
and has also been successfully applied to the preparation of
multi-kilogram quantities of aromatic sulfurpenta¯uoride
compounds.
2
2
2
reaction mixture. Using this procedure, bis(4-nitrophenyl)-
disul®de 3b gave an isolated yield of (4-nitrophenyl)sulfur-
penta¯uoride 4b of 41%. The use of chloroform as solvent
proved to be less successful, giving signi®cantly lower
yields of the desired product. Further improvements in
yield could be achieved by allowing the reaction mixture
to warm to room temperature after the initial formation of
the intermediate sulfurtri¯uoride compound. Direct ¯uori-
nation of 4-nitrothiophenol 1b or the thioether 2b in aceto-
nitrile gave lower yields of the desired 4-nitrophenyl
sulfurpenta¯uoride 4b, despite the fact that the thiol
substrate is observed to proceed via the same disul®de 3b
used above. Direct ¯uorination in acetonitrile could also be
carried out successfully starting from bis(3-nitrophenyl)-
disul®de 3a, affording the desired nitrophenyl sulfurpenta-
Having established a new method for the preparation of
aromatic sulfurpenta¯uorides, we were keen to demonstrate
further the synthetic utility of these materials. As described
8
earlier, Sheppard has reported reduction of nitrophenyl
sulfurpenta¯uorides to the corresponding amines using
catalytic hydrogenation methods. Subsequent diazotisation
of the resulting amines was also described in the same
article. With these methods as a starting point, a variety of
new aromatic sulfurpenta¯uorides were prepared, using
some common synthetic, and in particular cross-coupling,
methodologies.
¯
uoride 4a in 39% yield. Again the yields for this reaction
were improved by allowing the intermediate tri¯uoride
compound to warm to room temperature before continuing
¯
uorination. Unfortunately, the direct ¯uorination method-
ology could not be applied fully to the ortho substituted
2
0
starting materials, which gave only the intermediate
tri¯uorosulfur compounds as the major products. Presu-
mably, the steric hindrance from the ortho-nitro substituent
In the ®rst instance, reduction of the nitro groups by hydro-
genation, as described by Sheppard, using PtO in ethanolic
HCl, proved unsuccessful, giving only low yields of the
2

R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
3401
Figure 2. Molecular structures of: (a) 10a, and (b) 10b determined by X-ray diffraction.
2
2,23
desired amines 5a and 5b, as the corresponding hydro-
chloride salts. The same reactions carried out in the absence
of HCl also failed to give signi®cant quantities of the
amines. Successful reduction was achieved readily,
however, by employing 10% Pd on charcoal as the catalyst,
under an atmosphere of hydrogen in ethanol as solvent. This
gave high yields of the desired amines 5a and 5b.
acceptable yields. Similarly, reaction
phenyltributylstannane using toluene as solvent and
of 6a and 6b with
Pd(PPh ) as catalyst afforded the biphenyls 7a and 7b in
3
good to excellent yields. Disappointingly, reaction
and 6b with phenylmagnesium bromide in diethyl ether in
the presence of Ni(dppe)Cl Ðthe Kharasch reactionÐ
2
afforded no signi®cant quantities of 7a and 7b. Pd catalysed
4
22,24
of 6a
2
5
cross-coupling of 6a and 6b with phenylacetylene gave the
desired acetylenic products 8a and 8b in acceptable yields.
Rigorous deoxygenation of the solvent was essential in these
reactions to prevent the formation of signi®cant quantities of
1,4-diphenyl-1,3-butadiyne arising from homo-couping of
the alkyne starting material. However, small quantities of
1,4-diphenyl-1,3-butadiyne present in the crude products
could be removed successfully by ¯ash column chromato-
graphy. As a ®nal test of the stability of the aryl sulfurpenta-
¯uorides to Pd-mediated chemistry, the iodides 6a and 6b
1
6
Amines 5a and 5b were diazotized (Scheme 1) by the
addition of an aqueous solution of sodium nitrite to a slurry
of the amine hydrochloride in dilute hydrochloric acid. The
aromatic diazonium salts were then trapped successfully by
pouring the aqueous solution of the salt slowly into an
aqueous solution of potassium iodide at 08C, affording the
two aromatic iodides 6a and 6b. Reversing the order of
addition in this reaction, i.e. addition of the amines to an
aqueous solution of sodium nitrite and HCl, followed by
addition of aqueous KI solution to the diazonium salt,
gave generally lower yields of the iodides.
2
6
were reacted with methyl acrylate under Heck conditions
to afford the corresponding acrylates 9a and 9b in good yield.
2
7±29
We wished to test the stability of the sulfurpenta¯uoride
group to reaction conditions employed in common synthetic
transformations. In particular, we were interested in metal-
catalysed cross-coupling reactions. Therefore, iodides 6a
and 6b were reacted in a series of Pd(0) catalysed reactions
giving generally high yields of cross-coupled products.
Although there are several reported
crystal structures of
alkyl sulfurpenta¯uorides, there have been no crystal struc-
tures of aromatic sulfurpenta¯uorides described to date.
Therefore, we prepared the acetamides 10a and 10b
(Scheme 1) in the hope that single crystals of these
compounds, suitable for X-ray diffraction studies, could
be grown. Slow evaporation of dichloromethane solutions
of 10a and 10b afforded plate-like single crystals of the
acetamides which proved to be suitable for X-ray crystal-
lographic analysis.
2
2
Thus, 6a and 6b were reacted with phenylboronic acid,
in the presence of sodium carbonate, using a mixture of
dimethoxyethane and ethanol as solvent and Pd(PPh ) as
3
4
catalyst, to afford the corresponding biphenyls 7a and 7b in
Figure 3. Packing diagram for the solid state structure of 10a determined by X-ray diffraction. Molecules are shown in ball-and-stick representation and the
structure is being viewed along the crystallographic c axis. Dashed lines represent N±H´´´O hydrogen bonds.

3
402
R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
Figure 4. Packing diagram for the solid state structure of 10b determined by X-ray diffraction. Molecules are shown in ball-and-stick representation and the
structure is being viewed: (a) along the crystallographic b axis; and (b) along the crystallographic c axis. Dashed lines represent N±H´´´O hydrogen bonds. The
bold arrows in (b) represent the directions of hydrogen bonding in the tapes formed by 10b.
The structures of 10a and 10b (Fig. 2) were determined
from single crystal X-ray diffraction data and demonstrate
quadrant contains two hydrogen bonded tapes which have
the same molecular orientation and direction. Quadrant A is
that, in both cases, the sulfur atom of the SF group is in an
5
related to quadrant B by a C axis thus the tapes in quadrant
2
approximately octahedral environment.
B have the same directionality with respect to the b axis as
A, but have reversed molecular orientations. Tapes in
quadrant C have the same molecular orientations as those
in A, but reversed directionality (Fig. 4b) with respect to the
b axis. The same relationship holds between quadrants B
and D.
Within the SF groups, all S±F bond lengths are approxi-
5
Ê
Ê
mately 1.58 A, with the C±S bond length being 1.81 A. In
both 10a and 10b, the F±S±F bond angles are 908 between
two equatorial F atoms, and 878 between an equatorial F
atom and the axial F atom. In both cases, the equatorial F
atoms of the SF groups adopt an approximately staggered
5
In order to provide a direct comparison of the stability of the
sulfurpenta¯uoride group with that of the tri¯uoromethyl
group, we attempted to hydrolyse 4-aminophenylsulfur-
penta¯uoride 5b under acidic and basic conditions. Using
concentrated sulfuric acid at elevated temperatures, it has
conformation with respect to the aromatic ring. In 10a, the
F±S±C±C dihedral angles are 50 and 408, whilst in 10b they
are 60 and 308. The central plane of the SF group is
5
distorted away from the aromatic ring slightly, as evidenced
by the small reduction in the F±S±F bond angles between
the equatorial and axial F atoms. This distortion presumably
arises as a result of steric interactions with the ortho hydro-
gen atoms of the aromatic ring.
3
2,33
been shown
that 2- and 4-aminobenzotri¯uoride both
hydrolyse to give, after aqueous work-up of the intermediate
acyl¯uoride, the corresponding aminobenzoic acids.
Sheppard has also shown that phenylsulfurpenta¯uoride
8
is susceptible to hydrolysis by concentrated sulfuric acid,
giving phenylsulfonyl ¯uoride (40%) and phenylsulfonic
acid (not isolated). Using analogous conditions 4-amino-
phenylsulfurpenta¯uoride 5b was treated with concentrated
sulfuric acid at approximately 1608C over a period of 18 h.
Dilution of the reaction mixture with water and extraction
with ethyl acetate gave no isolable materials. Increasing the
pH of the aqueous phase with dilute aqueous sodium bicar-
bonate, and further extraction with ethyl acetate also failed
to give identi®able compounds. It would appear that,
similarly to Sheppard's work, and in common with aromatic
3
Compound 10a crystallises in the P2 2 2 space group
with four molecules occupying the unit cell. In the solid
state structure of 10a, molecules of 10a are oriented (Fig.
0
1
1 1
3) by N±H´´´O hydrogen bonds between adjacent aceta-
mido groups such that molecular tapes are formed which
run parallel to the crystallographic a axis. These tapes pack
in an antiparallel fashion to form corrugated sheets which lie
approximately in the ab plane. The SF groups of molecules
5
in adjacent tapes pack together, although there are no close
contacts between the SF group and other surrounding func-
tional groups.
5
tri¯uoromethyl compounds, the SF group is unstable to
5
concentrated sulfuric acid at elevated temperatures, and
that the resulting sulfonic acids are not isolable. It is also
possible that the electron donating amine group activates the
ring towards direct electrophilic sulfonation, and that again
the resulting sulfonic acids are not isolable.
3
Compound 10b crystallises in the Pca2 space group with
1
1
eight molecules occupying the unit cell. In the solid state
structure of 10b, molecules of 10b are oriented (Fig. 4) by
N±H´´´O hydrogen bonds between adjacent acetamido
groups such that molecular tapes are formed which run
parallel to the crystallographic b axis. The packing of
these tapes is, however, somewhat complex. The unit cell
may be divided (Fig. 4a) into four quadrants, A±D. Each
By way of contrast, 5b was recovered cleanly and in high
yield (91%) when stirred with 2N aqueous sodium
hydroxide solution at room temperature for 48 h. At ®rst

R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
3403
Figure 5. (a) Mechanism for hydrolysis of 4-aminobenzotri¯uoride. (b) Required conformation for hydrolysis of 4-aminosulfurpenta¯uoride. (c) Schematic
diagram of staggered conformation for benzotri¯uorides and both staggered and eclipsed conformations for aryl sulfurpenta¯uorides.
glance this result might be considered surprising, given that
3
In order to gain some insight into the electronic effect of the
SF group on the aromatic ring, we performed ab initio
4±36
4
-aminobenzotri¯uoride readily hydrolyses
to 4-amino-
5
benzoic acid in 1N sodium hydroxide solution after only 2 h.
Presumably, the mechanism for the latter transformation is
one involving direct deprotonation of the amine by hydrox-
ide, with the nitrogen anion resonance stabilised by the CF3
group, with loss of ¯uoride anion (Fig. 5a). Subsequent
addition of water to the intermediate 11, followed by loss
of HF and hydrolysis of the resulting acyl¯uoride, gives 4-
aminobenzoic acid 12.
molecular orbital calculations on 5a and 5b and the corre-
sponding benzotri¯uorides at the HF/6-31G(d) level of
theory.
The calculated structures of 5a and b, and, in particular, the
geometry of the SF group, are in close agreement with the
5
geometry anticipated from the solid state structures of 10a
and 10b. We were particularly interested in the electronic
effect of the SF group on amine basicity when compared to
5
For the analogous SF compound, however, it is more dif®-
5
the corresponding benzotri¯uoride. Therefore, the ab initio
wavefunctions were used to derive selected molecular prop-
erties and to generate electrostatic potential (ESP) surfaces
for 5a and 5b and the corresponding benzotri¯uorides (the
results of these calculations are presented in Table 1). It is
cult to stabilise the nitrogen anion by loss of ¯uoride (Fig.
5
p
b). The s orbital of the equatorial S±FLG bond is less able
to accept electron density from the aromatic ring due to
electron repulsion with the electrons within the S±FA
s
bond and therefore it cannot readily eliminate ¯uoride in
the same manner as for 4-aminobenzotri¯uoride. A differ-
ence in the assumed conformational preferences for the two
systems also allows a rationalisation of the above results.
In the benzotri¯uoride systems, a staggered conformation
clear from the data presented in Table 1 that the SF group,
5
9
in agreement with work described by Sheppard, is consid-
erably more electron withdrawing than the CF group. The
3
electrostatic potential on nitrogen is diminished signi®-
cantly and the molecular dipole increased signi®cantly
upon exchange of a CF group for an SF group.
of the CF group relative to the aryl ring always leaves one
3
3
5
of the F atoms in the correct alignment (i.e. perpendicular
to the plane of the aromatic ring) for elimination of HF to
occur. In the SF system the SF group must rotate into an
In conclusion, this paper describes a new, straightforward
method for the preparation of aromatic sulfurpenta¯uoride
compounds in good yields, using readily available starting
materials, which is a signi®cant improvement on current
methodology. The procedure is amenable to scale-up and
can be used to prepare multigram quantities of the desired
sulfurpenta¯uoride compounds without the use of expensive
reagents such as silver ¯uoride. The synthetic utility and
stability of the sulfurpenta¯uoride group has been estab-
lished for a variety of common synthetic transformations,
5
5
eclipsed, and therefore energetically less favourable,
conformation for correct orbital alignment (and thus loss
of HF) to occur (Fig. 5c). In solution, all four equatorial
1
9
¯
the SF group is either rotating freely around the C±S bond,
uorine atoms are equivalent by F NMR, suggesting that
5
or that the SF group sits in the staggered conformation
5
described above. In either situation the SF group does not
5
reach the required, and sterically unfavoured, conformation.
Table 1. Calculated (HF/6-31G(d)) properties of aminophenyl sulfurpenta¯uorides 5a and 5b and the corresponding benzotri¯uorides
Structure
a
ESPmin (NH
Dipole (D)
2
)
211.1
5.22
233.8
3.70
28.23
6.27
212.5
4.87
a
Minimum value (in kcal) of the electrostatic potential surface centred on the nitrogen atom of the amino group.

3
404
R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
giving generally good yields of cross-coupling products
when used in palladium-catalysed chemistry. Only when
treated under very harsh hydrolysis conditions does the
sulfurpenta¯uoride group undergo decomposition. It should
be noted that the yields reported in Scheme 1 are from
unoptimised synthetic procedures. We have also reported
here the ®rst two crystal structures obtained for aromatic
sulfurpenta¯uorides.
phenyl)disul®de (25.0 g, 81.1 mmol) was suspended in
anhydrous acetonitrile (270 ml) in a refrigerated stirred
tubular glass reaction vessel at 2108C. Fluorine (44.7 g,
1176 mmol, 14.5 equiv.), diluted to 10% in nitrogen, was
then bubbled through the suspension which was kept
between 27.6 and 24.58C for 6 h. The resulting solution
was poured onto water and treated with sodium hydroxide
solution until alkaline. The resulting mixture was then
extracted with dichloromethane (4£100 ml), the combined
extracts were dried (MgSO ) and solvent removed under
4
Experimental
General procedures
reduced pressure to give a brown oil. The product was
puri®ed by distillation at 1068C, 2 mmHg (lit. 858C,
8
2.6 mmHg) to give (3-nitrophenyl)sulfurpenta¯uoride 4a
as a yellow oil (7.88 g, 39%); R 0.50 (20% diethyl ether
f
1
in hexane); Found 248.987316 (M ), C H F NO S requires
Thin layer chromatography was carried out using Kieselgel
6
4
5
2
2
1
6
¯
0 aluminium or glass backed plates containing a UV
uorescent indicator (F 254 nm). Plates were visualised by
UV or using KMnO or I /SiO . Flash column chroma-
248.988291; nmax(neat)/cm 3114, 2879, 1609, 1540,
1356, 893 (S±F/NO ), 847 (S±F/NO ), 736, 722, 670,
2
2
2
601; lmax (CH CN)/nm (e/dm mol cm ) 213 (35000),
3
21
21
4
2
2
3
tography was carried out using Kieselgel 60, particle size
0±63 mm (230±400 mesh). Infra red spectroscopy was
251 (21000), 361 (2100); d (CDCl , 300 MHz) 8.65 (1H,
H
3
4
dd, Jˆ2 Hz, 2, H ), 8.42 (1H, d, Jˆ8 Hz, H or H ), 8.11
2
4
6
performed on a Perkin Elmer Paragon 1000 FTIR spectro-
meter using 16 scans. Oils were run neat between two
sodium chloride plates and solids were run as solutions in
dichloromethane. In all cases spectra were compared with
background spectra obtained using clean sodium chloride
plates or neat dichloromethane as appropriate. Nuclear
magnetic resonance (NMR) spectroscopy was performed
on Bruker AC300 and DRX500 spectrometers. Solvents
and operating frequencies are given for each compound.
(1H, dd, Jˆ8, 1.5 Hz, H or H ), 7.73 (1H, dd, Jˆ8, 8 Hz,
5 H 3 3
6 4
H ); d (CD COCD , 300 MHz), 8.64 (1H, dd, Jˆ2, 2 Hz,
H ), 8.55 (1H, dm, Jˆ8.5 Hz, H or H ), 8.36 (1H, dd, Jˆ8,
2
4
6
1.5 Hz, H or H ), 7.99 (1H, dd, Jˆ8.5, 8 Hz, H , d (CDCl ,
6
4
5
F
3
282 MHz) 81.2 (1F, quintet, Jˆ151 Hz, SF ), 62.9 (4F, d,
ax
Jˆ151 Hz, 4£SF ); d (CDCl , 75.5 MHz) 154.0 (apparent
eq
C
3
t, Jˆ21 Hz, C±SF ), 147.8 (C±NO ), 131.7 (quintet,
5
2
Jˆ4.5 Hz, CH), 130.1 (CH), 126.4 (CH), 121.8 (bm, CH);
(CD COCD , 75.5 MHz) 154.0 (apparent t, Jˆ19 Hz,
d
C
3
3
1
H spectra were referenced against residual CHCl3 at
C±SF ), 148.7 (C±NO ), 132.5 (quintet, Jˆ4.5, CH),
5
2
d ˆ7.26 ppm (CDCl solvent) or against the centre line
131.7 (CH), 127.6 (CH), 121.8 (quintet, Jˆ5 Hz, CH); m/z
H
3
1
(EI1, 70 eV) 249 (M1, 100%), 230 [(M2F) , 13], 203
of residual CHD COCHD at d ˆ2.04 ppm (CD COCD
2
2
H
3
3
3
1
9
solvent). F NMR spectra were referenced against CFCl
1
[(M2NO ) , 50], 111 (13), 95 (91), 75 (100) and 50 (48).
2
1
3
at d ˆ0.0 ppm. C NMR spectra were referenced against
F
6
,8
the centre line of the CDCl triplet set to a value of
3
(4-Nitrophenyl)sulfurpenta¯uoride 4b.
Bis(4-nitro-
d ˆ77.0 ppm (CDCl solvent) or against the centre peak
phenyl)disul®de (85%, 14.51 g, 40 mmol) was suspended
in acetonitrile (200 ml) and cooled to 278C whilst purging
with nitrogen. Fluorine (19.82 g, 521.6 mmol, 13.0 equiv.),
diluted to 10% in nitrogen, was then bubbled through the
suspension which was kept between 27.68C and 24.58C for
24 h. The solvent was removed from the pale yellow solu-
tion to give a dark red oily liquid which was dissolved in
dichloromethane (200 ml) and washed with 10% aqueous
sodium hydroxide solution (2£30 ml) followed by water
C
3
for the solvent CD resonance set to a value of
3
d ˆ29.8 ppm (CD COCD solvent) and were run using
C
3
3
the PENDANT sequence. Coupling constants are quoted
to the nearest 0.5 Hz. Low and high resolution mass spectro-
scopic data were obtained on either VG Zabspec or VG
Prospec mass spectrometers. All spectra were obtained by
electron ionisation mass spectroscopy (EIMS) at 70 eV.
Melting points were measured using an Electrothermal
9200 melting point apparatus and are uncorrected. UV/
(2£30 ml). After drying (MgSO ), the solvent was removed
4
visible spectra were recorded on a Hewlett Packard 8450A
diode array spectrophotometer at room temperature (ca
258C). Single crystal X-ray diffraction experiments were
carried out using graphite-monochromated MoKa radiation
to give a dark red liquid. The crude material was puri®ed by
vacuum distillation to (4-nitrophenyl) sulfurpenta¯uoride
4b as a low melting yellow solid (8.10 g, 41%); mp 38±
8
408C (lit. 388C); R 0.33 (25% dichloromethane in hexane);
f
Ê
1
Found 248.987910 (M ), C H F NO S requires
(
lˆ0.71069 A,) on a Rigaku R-Axis II diffractometer
6
4
5
2
2
1
equipped with an area detector and a rotating anode source.
Both structures reported here were solved and re®ned by
standard methods.
248.988291; nmax(neat)/cm 3116, 3068, 2989, 2880,
1931, 1793, 1613, 1531, 1487, 1409, 1357, 1101, 853 (S±
3
7±39
All ab initio molecular orbital calcu-
F/NO ), 603, 577; d (CDCl , 300 MHz) 8.33 (2H, d,
2
H
3
lations were performed using Spartan (Version 5.1.3, Wave-
function Inc., Irvine, CA., 1999). Initial input geometries
were generated using the Spartan Builder and all structures
were then optimised at the HF/3-21G level of theory. The
results of these calculations were then used as starting points
for calculations at the HF/6-31G(d) level of theory.
Jˆ9 Hz), 7.97 (2H, d, Jˆ9 Hz); dF (CDCl , 282 MHz)
3
81.2 (1F, quintet, Jˆ151 Hz, SF ), 62.7 (4F, d,
ax
Jˆ149 Hz, 4£SF ); d (CDCl , 75.5 MHz) 157.7 (m,
eq
C
3
C±SF ), 149.1 (C±NO ), 127.6 (quintet, Jˆ5 Hz, C and
5
2
2
1
C ), 124.1 (C and C ); m/z (EI1, 70 eV) 248 (M , 85%,
6
3
1
5
1
229 [(M2F) , 14], 203 [(M2NO ) , 42], 95 (80), 75 (100)
2
and 50 (51).
Synthetic procedures
6
3-Aminophenyl)sulfurpenta¯uoride 5a. Palladium on
,8
(
carbon [10% (w/w) Pd, 0.80 g, 0.75 mmol] was added in
6
,8
(
3-Nitrophenyl)sulfurpenta¯uoride 4a.
Bis(3-nitro-

R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
3405
one portion to a solution of (3-nitrophenyl)sulfurpenta-
uoride (3.75 g, 15.05 mmol) in ethanol (degassed,
7 ml). The mixture was stirred under an atmosphere of
hydrogen until complete consumption of starting material
TLC analysis). The mixture was ®ltered to remove the
hexane) to give (3-iodophenyl)sulfurpenta¯uoride 6a as a
colourless oil (1.4 g, 63%); R 0.60 (20% dichloromethane
¯
4
f
1
in hexane); Found 329.899472 (M ), C H F IS requires
6
4 5
2
1
329.899865; nmax(neat)/cm
1953, 1891, 1764, 1700, 1574, 1464, 1416, 1110, 1065,
3097, 3068, 2925, 2871,
(
catalyst, and the solvent removed under reduced pressure.
The crude product was puri®ed by column chromatography
996, 836 (S±F), 782, 710, 681, 661, 599; dH (CDCl3,
300 MHz) 8.07 (1H, dd, Jˆ2, 2 Hz, H ), 7.85 (1H, d,
2
(25% dichloromethane in hexane) to afford (3-amino-
phenyl)sulfurpenta¯uoride 5a as a yellow oil that slowly
Jˆ8 Hz, H or H ), 7.73 (1H, dd, Jˆ8, 2 Hz, H or H ),
4
6
6
4
7.20 (1H, dd, Jˆ8, 8 Hz, H ); d (CDCl , 282 MHz) 83.2
ax
5
F
3
8
crystallised (2.3 g, 70%); mp 35±368C (lit. 378C); R 0.40
(1F, quintet, Jˆ150 Hz, SF ), 62.9 (4F, d, Jˆ151 Hz,
f
(
(
25% dichloromethane in hexane); Found 219.014196
M ), C H F NS requires 219.014112; nmax(neat)/cm
4£SF ); d (CDCl , 75.5 MHz) 154.4 (apparent t,
eq
C
3
1
21
Jˆ18 Hz, C±SF ), 140.6 (C or C ), 134.6 (quintet,
6
6
5
5
5
4
3
1
3
472 (b), 3400 (b), 3219, 3061, 1934, 1852, 1718, 1636,
494, 1312, 1127, 1093, 920, 853 (S±F); dH (CDCl3,
Jˆ5 Hz, C or C ), 130.2 (C or C ), 125.1 (quintet,
2 6 4 5
Jˆ5 Hz, C or C ), 93.1 (C±I); m/z (EI1, 70 eV) 330
2 6
1
(M , 100%), 311 [(M2F) , 5] 222 [(M2SF ) , 10], 203
1
1
00 MHz) 7.23 (1H, ddm, Jˆ8, 8 Hz, H ), 7.15 (1H, dd,
5
4
1
[(M2I) , 60], 127 (15), 95 (63), 76 (14) and 50 (3).
Jˆ2, 2 Hz, H ) 7.01, (1H, dd, Jˆ8, 2 Hz, H or H ), 6.88
2
4
6
(
(
4
1H, dd, Jˆ8, 2 Hz, H or H ); d (CDCl , 282 MHz), 85.5
ax
6
4
F
3
1F, quintet, Jˆ150 Hz, SF ) 62.5 (4F, d, Jˆ149 Hz,
(4-Iodophenyl)sulfurpenta¯uoride 6b. Prepared accord-
ing to the above procedure using (4-aminophenyl)sulfur-
penta¯uoride (1.00 g, 4.56 mmol), sodium nitrite (0.35 g,
5.02 mmol), HCl (12 M, 18 ml), potassium iodide (7.58 g,
45.6 mmol) and water (31 ml). The crude product was puri-
®ed by column chromatography (hexane) to give (4-iodo-
phenyl)sulfurpenta¯uoride 6b as a white solid (0.75 g,
£SF ); d (CDCl , 75.5 MHz) 154.8 (apparent t,
eq
C
3
Jˆ16 Hz, C±SF ), 146.6 (C±NH ), 129.3 (CH), 117.6
5 2
(
CH), 115.7 (quintet, Jˆ5 Hz, CH), 112.1 (quintet,
1
Jˆ5 Hz, CH); m/z (EI1, 70 eV) 219 (M , 100%), 111
(
32), 92 (74) and 65 (52).
6
,8
(
4-Aminophenyl)sulfurpenta¯uoride 5b.
Prepared
50%); R 0.60 (hexane); mp 38±398C; Found 329.898704
f
1
21
according to the above procedure using (4-nitrophenyl)-
sulfurpenta¯uoride (6.00 g, 24.1 mmol) and palladium on
carbon (10% w/w Pd, 3.26 g, 1.2 mmol) in ethanol
(M ), C H F IS requires 329.899865; nmax(neat)/cm
6 4 5
2991, 2926, 2855, 1912, 1785, 1643, 1605, 1572, 1485,
1473, 1391, 1102, 1064, 1007, 860 (S±F), 797, 658, 599,
(
degassed, 75 ml). The crude product was puri®ed by
recrystallisation (diethyl ether/hexane) to give (4-amino-
580; dH (CDCl , 300 MHz) 7.80 (2H, d, Jˆ8.5 Hz,
3
2£aromatic CH), 7.47 (2H, d, Jˆ9 Hz, 2£aromatic CH);
d (CDCl , 282 MHz) 83.6 (1F, quintet, Jˆ150 Hz, SF ),
phenyl)sulfurpenta¯uoride 5b as a pale yellow solid
(
dichloromethane in hexane); Found 219.013347 (M ),
F
3
ax
8
2.55 g, 48%); mp 57±598C (lit. 688C); R 0.40 (25%
62.8 (4F, d, Jˆ151 Hz, 4£SF ); d (CDCl , 75.5 MHz)
f
eq
C
3
1
153.5 (apparent t, Jˆ18 Hz, C±SF ), 137.9 (C and C ),
5 3 5
2
1
C H F NS requires 219.014112; nmax(neat)/cm
3496
b, N±H), 3403 (b, N±H), 3214, 3054, 2990, 1895, 1764,
626, 1600, 1507, 1304, 1194, 1099, 858 (S±F), 582; dH
127.5 (quintet, Jˆ4.5 Hz, C and C ); m/z (EI1, 70 eV)
330 (M , 100%), 311 [(M2F) , 3], 222 (26), 203 (25),
6
6
5
2 6
1
1
(
1
127 (14), 95 (86), 76 (66) and 50 (43).
(
CDCl , 300 MHz) 7.51 (2H, dm, Jˆ9 Hz, 2£aromatic
3
8
(3-Biphenyl)sulfurpenta¯uoride 7a. Suzuki coupling
CH), 6.60 (2H, d, Jˆ9 Hz, 2£aromatic CH), 3.85 (2H, bs,
NH ); d (CDCl , 282 MHz) 88.3 (1F, quintet, Jˆ150 Hz,
reaction: 3-(Iodophenyl)sulfurpenta¯uoride (0.25 g, 0.76
mmol) was added to a suspension of tetrakis(triphenyl-
phosphine)palladium (40 mg, 0.04 mmol) in dimethoxy-
ethane (11 ml) and stirred for 10 min under N2 at rt.
Phenylboronic acid (0.14 g, 1.14 mmol) in ethanol (2 ml)
and Na CO (0.16 g, 1.52 mmol) in water (,2 ml) were
2
F
3
SF ), 64.9 (4F, d, Jˆ149 Hz, 4£SF ); d (CDCl ,
ax
eq
C
3
7
5.5 MHz) 148.9 (C±NH ), 144.3 (apparent t, Jˆ17 Hz,
2
C±SF ), 127.4 (quintet, Jˆ4.5, C and C ), 113.4
5
2
6
1
(
[
(
2£CH); m/z (EI1, 70 eV) 219 (M , 100%), 200
1
(M2F) , 9], 111 (100), 92 (50), 84 (19), 65 (67), 52
10), and 39 (30).
2
3
added and the resulting mixture was heated to re¯ux for
h. On cooling, dichloromethane (50 ml) was added, and
the organic phase was dried (MgSO ). The resulting solution
3
(
(
3-Iodophenyl)sulfurpenta¯uoride 6a. A solution of cold
08C) NaNO (0.5 g, 7.5 mmol) in water (5 ml) was added
4
w
was ®ltered through Celite (1 cm depth) and the solvent
2
slowly to a cold (08C) solution of (3-aminophenyl)sulfur-
penta¯uoride (1.5 g, 6.8 mmol) in HCl (12 M, 3 ml,
removed under reduced pressure. The crude product was
puri®ed by column chromatography (hexane) to give
(3-biphenyl)sulfurpenta¯uoride 7a as a colourless oil
3
.7 mmol) and ice (5 g). The mixture was stirred at 08C
for a further 2 min before being added slowly, over
0 min, to a solution of KI (11.3 g, 6.8 mmol) in water
40 ml), whilst ensuring the temperature was kept below
08C at all times. The mixture was left for 30 min in ice
(0.20 g, 93%); R 0.40 (100% hexane); Found 280.035674
f
1
21
1
(
1
(M ), C H F S requires 280.034513; nmax(neat)/cm
12 9 5
3068, 3034, 1953, 1893, 1599, 1568, 1476, 1417, 1114,
1022, 837 (S±F), 796, 756, 697, 648, 596; dH (CDCl3,
and then allowed to warm to rt. The product was extracted
with dichloromethane (3£180 ml), and the combined
extracts were then washed with saturated aqueous
300 MHz) 7.95 (1H, dd, Jˆ2, 2 Hz, H ), 7.75±7.70 (2H,
2
m), 7.61±7.40 (6H, m); d (CDCl , 282 MHz) 84.7 (1F,
F
3
pentet, Jˆ150 Hz, SF ), 62.9 (4F, d, Jˆ149 Hz, 4£SF );
ax
eq
NaHCO3 solution (3£100 ml) and dried (MgSO ) and
d (CDCl , 75.5 MHz) 154.5 (m, C±SF ), 142.3 (quaternary
C 3 5
4
decolorized (activated charcoal). After ®ltration through
Celite (1 cm depth) the solvent was removed under
C), 139.4 (quaternary C), 130.2 (CH), 129.1 (3£CH), 128.2
w
(CH), 127.2 (2£CH), 124.7 (quintet, Jˆ5 Hz, C or C ),
2
6
reduced pressure to give a yellow oil which was puri®ed
by column chromatography (12% dichloromethane in
124.6 (quintet, Jˆ5 Hz, C or C ); m/z (EI1, 70 eV) 280
6
2
1
(M , 100%), 172 (22), 152 (53) and 76 (8).

3
406
R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
8
3-Biphenyl)sulfurpenta¯uoride 7a. Stille coupling
(
reaction: Toluene (25 ml) and tetrakis(triphenylphos-
phine)palladium (40 mg, 0.04 mmol) were added to
concentrated under reduced pressure to give a brown
solid. Puri®cation of the crude product by column chroma-
tography (hexane) gave (3-(2-phenylethyn-1-yl)phenyl)-
sulfurpenta¯uoride 8a as a colourless oil (198 mg, 75%);
(
3-iodophenyl)sulphurpenta¯uoride (0.25 g, 0.76 mmol)
and stirred under N for 10 min. Phenyltributylstannane
1
R 0.65 (hexane); Found 304.033971 (M ), C H F S
f
2
14
9 5
2
1
(0.30 g, 0.90 mmol) was added in one portion and the
mixture was heated to re¯ux for 18 h. On cooling, dichloro-
requires 304.034513; nmax(neat)/cm 3082, 2927, 2359,
2230, 1954, 1896, 1830, 1752, 1708, 1603, 1494, 1477,
1444, 1421, 1106, 800, 820, 791, 755, 725, 684, 649, 599;
d (CDCl , 300 MHz) 7.97 (1H, bs, H ), 7.72 (1H, dd, Jˆ8,
methane (30 ml) was added, the organic phase was dried
(
w
MgSO ), and the resulting mixture ®ltered through Celite
4
H
3
2
(
1 cm depth). The solvent was removed under reduced
pressure to give a yellow oil that was puri®ed by column
chromatography (hexane) to give (3-biphenyl)sulfurpenta-
¯uoride 7a as a colourless oil (0.16 g, 76%) with spectro-
scopic data as above.
1.5 Hz, H or H ), 7.66 (1H, d, Jˆ8 Hz, CH), 7.61±7.56
(2H, m), 7.46±7.35 (4H, m); d (CDCl , 282 MHz) 83.8
F 3
4
6
(1F, quintet, Jˆ150 Hz, SF ), 62.7 (4F, d, Jˆ151 Hz,
ax
4£SF ); d (CDCl , 75.5 MHz) 153.8 (quintet, Jˆ18 Hz,
eq
C
3
C±SF ), 134.3 (CH), 131.7 (2£CH), 129.1 (quintet,
5
Jˆ4.5 Hz, C or C ), 128.9 (CH), 128.7 (CH), 128.4
2
6
(
4-Biphenyl)sulfurpenta¯uoride 7b. Suzuki coupling
reaction: Following the Suzuki coupling procedure above,
4-iodophenyl)sulfurpenta¯uoride (0.25 g, 0.76 mmol),
(2£CH), 125.4 (quintet, Jˆ4.5, C or C ), 124.4 (aryl
6
2
quaternary C), 122.4 (aryl quaternary C), 91.3 (alkyne
quaternary C), 87.3 (alkyne quaternary C); m/z (EI1,
(
1
70 eV) 304 (M , 100%), 196 (14), 176 (29), 151 (13), 98
(9).
tetrakis(triphenylphospine) palladium (0.04 g, 0.04 mmol),
phenyl boronic acid (0.14 g, 1.14 mmol) and sodium
carbonate (2M in water, 0.16 g, 1.52 mmol) in dimethoxy-
ethane (5 ml) and ethanol (1 ml) were heated at 858C for 2 h.
Work-up gave a crude product which was puri®ed by
column chromatography (hexane) to give (4-biphenyl)-
(4-(2-Phenylethyn-1-yl)phenyl)sulfurpenta¯uoride 8b.
Prepared according to the above Heck coupling procedure
using (4-iodophenyl)sulfurpenta¯uoride (0.15 g, 0.45 mmol),
triphenylphosphine (0.01 g, 0.05 mmol), palladium (II)
chloride (0.004 g, 0.02 mmol), copper (II) acetate mono
hydrate (0.004 g, 0.02 mmol) and phenylacetylene (0.06 g,
0.55 mmol) in diisopropylamine (2 ml). After 1.5 h at room
temperature work up gave a yellow oil. Attempted puri®-
cation by sublimation and distillation proved unsuccessful,
however, the product was successfully puri®ed by ¯ash
column chromatography (hexane) to give (4-(2-phenyl-
ethyn-1-yl)phenyl)penta¯uorosulfur 8b as a white solid
(0.07 g, 47%); mp 1338C; Rf 0.45 (hexane); Found
sulfurpenta¯uoride 7b as a white solid (2.55 g, 48%); mp
6
1
48C; R 0.40 (hexane); Found 280.035419 (M ), C H F S
f
12
9 5
2
1
requires 280.034513; nmax(neat)/cm 2926, 2854, 1598,
570, 1484, 1401, 1271, 1102, 842 (S±F), 596, 514; dH
1
(
CDCl , 300 MHz) 7.82 (2H, dd, Jˆ7, 2 Hz, 2£aromatic
3
CH), 7.65 (2H, d, Jˆ8.5 Hz, 2£aromatic CH), 7.60±7.57
(
(
2H, m), 7.51±7.44 (3H, m); d (CDCl , 282 MHz) 84.9
F 3
1F, quintet, Jˆ150 Hz, SF ), 63.3 (4F, d, Jˆ151 Hz,
ax
4
£SF ); d (CDCl , 75.5 MHz) 152.8 (apparent t,
eq
C
3
Jˆ17 Hz, C±SF ), 144.5 (quaternary C), 139.0 (quaternary
5
1
C), 129.0 (2£CH), 128.4 (C
0
), 127.3 (2£CH), 127.2
304.034792 (M ), C H F S requires 304.034513; nmax(neat)/
14
4
9 5
2
1
(
2£CH), 126.4 (quintet, Jˆ4.5 Hz, C and C ); m/z (EI1,
cm 2957, 2925, 2854, 2221, 1665, 1602, 1502, 1401,
1251, 1093, 862 (S±F), 781, 600, 583, 571; dH (CDCl3,
300 MHz) 7.73 (2H, d, Jˆ9 Hz, 2£aromatic CH), 7.60±
2
6
1
0 eV) 280 (M , 65%), 172 (100), 152 (37), 126 (8), 102
10), 86 (11), 76 (20), 63 (14) and 51 (19).
7
(
7
.53 (4H, m), 7.40±7.36 (3H, m); d (CDCl , 282 MHz)
F 3
(
4-Biphenyl)sulfurpenta¯uoride 7b. Stille coupling
84.2 (1F, quintet, Jˆ150 Hz, SF ), 62.8 (4F, d,
ax
reaction: Following the Stille coupling procedure above,
4-iodophenyl)sulfurpenta¯uoride (0.25 g, 0.76 mmol),
Jˆ149 Hz, 4£SF ); d (CDCl , 75.5 MHz) 153.0 (apparent
eq
C
3
(
t, Jˆ18 Hz, C±SF ), 131.8 (2£CH), 131.6 (2£CH), 129.0
5
tetrakis(triphenylphosphine) palladium (40 mg, 0.04 mmol)
and tris(n-butyl)phenylstannane (0.30 g, 0.91 mmol) in
toluene (4 ml) were heated to re¯ux for 18 h. Work up
gave a crude product which was puri®ed by column
chromatography (hexane) to give (4-biphenyl)sulfurpenta-
(CH), 128.5 (2£CH) 127.0 (aryl quaternary C), 126.0 (quin-
tet, Jˆ4.5 Hz, C or C ), 122.3 (aryl quaternary C), 92.4
2
6
(alkyne quaternary C), 87.3 (alkyne quaternary C); m/z
(EI1, 70 eV) 304 (M , 100%), 285 [(M2F) , 3], 196
(88), 176 (28), 151 (10), 126 (10) and 89 (17).
1
1
¯uoride 7b as a white solid (0.20 g, 94%); mp 678C with
spectroscopic data as above.
Methyl 2-(3-penta¯uorosulfurylphenyl)acrylate 9a.
Palladium acetate (7 mg, 0.03 mmol) and triphenylphos-
phine (16 mg, 0.06 mmol) were added to a solution of
(3-iodophenyl)sulfurpenta¯uoride (219 mg, 0.66 mmol) in
triethylamine (degassed, 2 ml). The resulting mixture was
warmed a little to dissolve all the solids and methyl acrylate
(115 mg, 1.3 mmol) was added. The resulting solution was
then heated to re¯ux overnight. Removal of the solvents
gave a brown oil that was puri®ed by ¯ash column
chromatography (15% ethyl acetate in hexane) to give
methyl 2-(3-penta¯uorosulfurphenyl)acrylate 9a as a pale
(
3-(2-Phenylethyn-1-yl)phenyl)sulfurpenta¯uoride 8a.
Copper (II) acetate hydrate (8 mg, 0.04 mmol), triphenyl-
phosphine (34 g, 0.13 mmol) and palladium (II) chloride
(
(
12 mg, 0.07 mmol) were added to a degassed mixture of
3-iodophenyl)sulfurpenta¯uoride (287 mg, 0.87 mmol) in
diisopropylamine (3 ml). The mixture was degassed further
then warmed to dissolve the solids before cooling to room
temperature. Phenylacetylene (107 mg, 1.04 mmol) was
added via a syringe, in small portions, to the vigorously
stirred mixture, over 20 min. The resulting mixture was
stirred at room temperature for 1.25 h before ®ltering
yellow oily solid (113 mg, 65%); R 0.75 (25% ethyl acetate
f
1
in hexane); Found 288.025233 (M ), C H F SO requires
1
0
9
5
2
w
w
21
through Celite (1 cm depth). The solid Celite cake was
washed with dichloromethane (3£50 ml) and the ®ltrate
288.024343; nmax(CH Cl )/cm 2954, 2848, 1720 (CvO),
2 2
1644, 1573, 1482, 1437, 1316, 1281, 1211, 1175, 1113, 979,

R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
3407
8
94, 841, 738, 681, 641, 599; dH (CDCl , 300 MHz) 7.87
3
(4-Acetamidophenyl)sulfurpenta¯uoride 10b. Prepared
according to the above procedure using (4-aminophenyl)-
sulfurpenta¯uoride (0.25 g, 1.14 mmol) and acetic
anhydride (13 ml). After 3 hours at room temperature
work up gave crude product which was puri®ed by recrys-
tallisation (diethyl ether/hexane) to give (4-acetamido-
phenyl)sulfurpenta¯uoride 10b as a white solid (0.11 g,
(
1H, bs, H ), 7.74 (1H, dd, Jˆ8, 1.5 Hz, H or H ), 7.70±
2
4
6
7
6
2
.63 (2H, m, H or H and H ), 7.48 (1H, t, Jˆ8 Hz, H ),
6
4
a
5
.49 (1H, d, Jˆ16 Hz, H ), 3.81 (3H, s, OCH ); d (CDCl ,
b 3 F 3
82 MHz) 83.7 (1F, quintet, Jˆ150 Hz, SF ), 62.6 (4F, d,
ax
Jˆ149 Hz, 4£SF ); d (CDCl , 75.5 MHz) 166.6 (CvO),
eq
C
3
1
54.5 (quintet, Jˆ17.5 Hz, C±SF ), 142.5 (CH), 135.5
5
(
quaternary C), 130.6 (CH), 129.3 (CH), 127.2 (quintet,
37%); mp 1318C; R 0.45 (25% dichloromethane in hexane);
f
1
Found 261.023719 (M ), C H F NOS requires 261.024677;
Jˆ4.5 Hz, C or C ), 125.4 (quintet, Jˆ4.5 Hz, C or C ),
2
6
6
2
8
8 5
1
20.4 (CH), 51.9 (OCH ); m/z (EI1, 70 eV) 288 (M , 46%),
2
21
1
nmax(CH Cl )/cm 3424 (N±H), 3045, 2990, 1705 (CvO),
2 2
3
1
57 [(M2OMe) , 100], 229 (13), 161 (4), 130 (20), 102
25), 75 (6), 45 (6).
1598, 1516, 1402, 1316, 1104, 856 (S±F), 820; d (CDCl ,
H 3
(
300 MHz) 7.69 (2H, d, Jˆ9 Hz, 2£aromatic CH), 7.61±
.58 (3H, m, 2£aromatic CH and NH), 2.21 (3H, s,
NHCOCH ); d (CD COCD , 300 MHz) 9.58 (1H, s,
7
Methyl 2-(4-penta¯uorosulfurylphenyl)acrylate 9b.
Using the above procedure a mixture of palladium acetate
3
H
3
3
NH), 7.83 (2H, d, Jˆ9 Hz, 2£aromatic CH), 7.76 (2H, d,
(
(
9 mg, 0.04 mmol), triphenylphosphine (22 mg, 0.08 mmol),
4-iodophenyl)sulfurpenta¯uoride (300 mg, 0.91 mmol)
Jˆ9 Hz, 2£aromatic CH), 2.13 (3H, s, NHCOCH ); d
3
F
(CD COCD , 282 MHz) 86.9 (1F, quintet, Jˆ149 Hz,
3
3
and methyl acrylate (157 mg, 1.8 mmol) in triethylamine
degassed, 3 ml) was heated to re¯ux overnight. Removal
SF ), 64.1 (4F, d, Jˆ148 Hz, 4£SF ); d (CD COCD ,
ax
eq
C
3
3
(
75.5 MHz) 169.5 (CONH), 148.4 (apparent t, Jˆ17 Hz,
C±SF ), 143.2 (C±NHCOCH ), 127.3 (quintet, Jˆ4.5 Hz,
of the solvents gave a brown oil that was puri®ed by ¯ash
column chromatography (25% ethyl acetate in hexane) to
give methyl 2-(4-penta¯uorosulfurphenyl)acrylate 9b as a
5
3
2£CHCSF ), 119.1 (2£CHCNR), 24.0 (CH ); m/z (EI1, 70
5
3
1
eV) 261 (M , 68%), 219 (100), 111 (89) and 43 (83).
yellow solid (150 mg, 57%); mp 78±808C; R 0.65 (25%
f
1
ethyl acetate in hexane); Found 288.023954 (M ),
2
1
C H F SO requires 288.024343; nmax(CH Cl )/cm
2
Acknowledgements
1
0
9
5
2
2
2
1
3
953, 1919, 1720 (CvO), 1643, 1578, 1504, 1327, 1293,
198, 1177, 1100, 982, 909, 846, 595, 581; dH (CDCl3,
00 MHz) 7.74 (2H, d, Jˆ9 Hz), 7.66 (1H, d, Jˆ16 Hz,
We thank the University of Birmingham for ®nancial
support of this work and Dr Paul Coe for useful discussions
and suggestions.
H ), 7.56 (2H, d, Jˆ9 Hz), 6.49 (1H, d, Jˆ16 Hz, H ),
a
b
3.81 (3H, s, OCH ); d (CDCl , 282 MHz) 83.8 (1F, quintet,
3 F 3
Jˆ151 Hz, SF ), 62.7 (4F, d, Jˆ149 Hz, 4£SF ); d
ax
eq
C
(
CDCl , 75.5 MHz) 166.6 (CvO), 154.5 (apparent t, Jˆ
References
3
18 Hz, C±SF ), 142.1 (CH), 137.5 (quaternary C), 128.0
5
(
(
(
C and C ), 126.5 (quintet, Jˆ4.5 Hz, C and C ), 121.0
1. Organo¯uorine ChemistryÐPrinciples and Commercial
Applications; Banks, R. E., Smart, B. E., Tatlow, J. C., Eds.;
Plenum Press: New York, London, 1994.
3
5
2
6
1
CH), 51.9 (OCH ); m/z (EI1, 70 eV) 288 (M , 53%), 257
100), 229 (7), 161 (12), 149 (11), 130 (80), 121 (45), 102 (44).
3
2
. Banks, R. E. In Fluorine: The First Hundred Years (1886±
(
3-Acetamidophenyl)sulfurpenta¯uoride 10a. (3-Amino-
1986); Banks, R. E., Sharp, D. W. A., Tatlow, J. C., Eds.; Elsevier
Sequoia: Lausanne, New York, 1986.
phenyl)sulfurpenta¯uoride (0.25 g, 1.14 mmol) was added
to acetic anhydride (13 ml) and the resulting mixture was
left to stir for 1.5 h. Dichloromethane (10 ml) was added
and the organic phase was washed with ice cold water
3. Filler, R. J. Fluorine Chem. 1986, 33, 361.
4. Welch, J. T. Tetrahedron 1987, 43, 3123.
5. Sheppard, W. A. Arylsulfurpenta¯uorides, US Patent 3219690,
1959.
(
3£50 ml) and dried (MgSO ). The solvent was removed
4
under reduced pressure to give a yellow oil which was
taken up in diethyl ether (100 ml) and washed with saturated
6. Sheppard, W. A. J. Am. Chem. Soc. 1960, 82, 4751.
7. Williams, A. G.; Foster, N. R. Process for the preparation of
aryl- and heteroarylsulphurpenta¯uorides, Patent WO9422817,
1994.
aqueous NaHCO solution (3£100 ml). The organic phase
3
was then dried (MgSO ), decolorized (charcoal) and ®ltered
4
w
through Celite (1 cm depth) and the solvent removed under
8. Sheppard, W. A. J. Am. Chem. Soc. 1962, 84, 3064.
9. Sheppard, W. A. J. Am. Chem. Soc. 1962, 84, 3072.
10. Taft, R. W.; Price, E.; Fox, I. R.; Lewis, I. C.; Andersen, K. K.;
Davis, G. T. J. Am. Chem. Soc. 1963, 85, 3146.
11. Taft, R. W.; Price, E.; Fox, I. R.; Lewis, I. C.; Andersen, K. K.;
Davis, G. T. J. Am. Chem. Soc. 1963, 85, 709.
12. Sheppard, W. A. J. Am. Chem. Soc. 1965, 87, 2410.
13. Brownlee, R. T. C.; Hutchinson, R. E. J.; Katritzky, A. R.;
Tidwell, T. T.; Topsom, R. D. J. Am. Chem. Soc. 1968, 90, 1757.
14. Brownlee, R. T. C.; English, P. J. Q.; Katritzky, A. R.;
Topsom, R. D. J. Phys. Chem. 1969, 73, 557.
15. Sheppard, W. A.; Taft, R. W. J. Am. Chem. Soc. 1972, 94,
1919.
reduced pressure. (3-Acetamidophenyl)sulfurpenta¯uoride
10a was isolated as colourless crystals (0.13 g, 42%); mp
1
2
nmax(CH Cl )/cm
(
46±1488C; Rf 0.17 (100% dichloromethane); Found
1
61.024824 (M ), C H F NOS requires 261.024677;
8
8 5
2
1
3426 (N±H), 3064, 3049, 1702
CvO), 1606, 1522, 1490, 1369, 1306, 854 (S±F), 819,
2
2
6
46, 597; dH (CD COCD , 300 MHz) 9.55 (1H, bs, NH),
3 3
8.36 (1H, s, H ), 7.81±7.77 (1H, m, H ), 7.56±7.49 (2H, m,
H or H ), 2.06 (3H, s, COCH ); d (CD COCD , 282 MHz)
8
4
(
2
5
4
6
3
F
3
3
5.7 (1F, quintet, Jˆ148 Hz, SF ), 62.9 (4F, d, Jˆ148 Hz,
ax
£SF ); d (CD COCD , 75.5 MHz) 169.6 (CvO), 154.5
eq
C
3
3
m, C±SF ), 140.9 (C-NHCOCH ), 130.1 (CH), 123.0 (CH),
5
3
1
21.0 (quintet, Jˆ5 Hz, C or C ), 117.1 (quintet, Jˆ5 Hz,
16. Salmon, R. Preparation of N-(4-penta¯uorosulfenylphenyl)-
pyrazoles as insecticides and acaricides, Patent WO 9306089,
1993.
2
6
1
C or C ); m/z (EI1, 70 eV) 261 (M , 30%), 219 (100), 134
6
2
(
12), 111 (40), 92 (25), 83 (6), 65 (15) and 43 (87).

3
408
R. D. Bowden et al. / Tetrahedron 56 (2000) 3399±3408
1
7. Howard Jr., M. H.; Stevenson, T. M. Arthropodicidal penta- 28. Winter, R.; Gard, G. L.; Mews, R.; Noltemeyer, M. J. Fluorine
Chem. 1993, 60.
29. Klauck, A.; Seppelt, K. Angew. Chem., Int. Ed. Engl. 1994, 33,
¯
uorothiosubstituted anilides, Patent WO 9516676, 1995.
18. Bowden, R. D.; Greenhall, M. P.; Moilliet, J. S.; Thomson, J.
The preparation of ¯uorinated organic compounds, Patent WO
93.
30. Crystal data for (3-acetamidophenyl)sulfurpenta¯uoride 10a:
9
1
705106, 1997.
9. See also: Jesih, A.; Sipyagin, A. M.; Chen, L.-F.; Hong,
C
8
H
8
F
5
NOS, Mˆ261.22, orthorhombic, space group P2
1 1 1
2 2 (no
Ê
1
9), aˆ9.8003 (11), bˆ17.894 (2), cˆ5.9141 (7) A, Vˆ1037.1
Ê
c
W.-D.; Thrasher, J. S. Abstracts of Papers of the American
Chemical Society 1993, 205 (Part 2), 171-POLY.
3
23
(
2) A , Zˆ4, D
ˆ1.673 g cm , 6361 re¯ections measured, 1842
unique, Rˆ0.0319. Full crystallographic data have been deposited
2
0. However, several ortho-substituted arylsulfurpenta¯uorides
at the Cambridge Crystallographic Data Centre.
3
have been prepared successfully by Thrasher. See: Sipyagin,
A. M.; Thrasher, J. S. Abstracts of Papers of the American
Chemical Society 1993, 206 (Part 1), 14-FLUO.
1. Crystal data for (4-acetamidophenyl)sulfurpenta¯uoride 10b:
NOS, Mˆ261.22, orthorhombic, space group Pca2 (no
C
8
H
8
F
5
1
Ê
2
9), aˆ23.706 (2), bˆ5.2534 (4), cˆ15.9163 (13) A, Vˆ1982.2
2
1
2
1. Kharasch, N.; Chamberlain, D. L. J. Am. Chem. Soc. 1955, 71,
041.
3
23
Ê
(
3) A , Zˆ8, D ˆ1.751 g cm , 10120 re¯ections measured, 3289
c
unique, Rˆ0.0335. Full crystallographic data have been deposited
2. For a recent review on the synthesis of biaryl systems using
at the Cambridge Crystallographic Data Centre.
Pd- or Ni-mediated cross-coupling reactions see: Stanforth, S. P.
3
3
2
3
2. Le Fave, G. M. J. Am. Chem. Soc. 1949, 71, 4148.
3. Le Fave, G. M.; Scheurer, P. G. J. Am. Chem. Soc. 1950, 72,
464.
Tetrahedron 1998, 54, 263.
2
3. Farina, V.; Scott, W. J.; Krishnamurthy, V. The Stille
Reaction, Wiley: New York, 1998.
4. Tamao, K.; Sumitani, K.; Kiso, Y.; Zembayashi, M.; Fujioka,
4. Grinter, R.; Heilbronner, E.; Petrzilka, T.; Seiler, P.
2
Tetrahedron Lett. 1968, 3845.
A.; Kodama, S.-I.; Nakajima, I.; Minato, A.; Kumada, M. Bull.
Chem. Soc. Jpn 1976, 49, 1958.
3
3
3
5. Jones, R. G. J. Am. Chem. Soc. 1947, 69, 2346.
6. Whalley, J. J. Chem. Soc. 1949, 3016.
25. Reaction performed using a slightly modi®ed version of a
procedure reported in: Robinson, J. M. A. Kariuki, B. M.; Harris,
7. Sheldrick, G. M. shelxs 86, Program for the solution of
crystal structures, University of G oÈ ttingen, Germany, 1990.
8. Sheldrick, G. M. shelxl 93, Program for the re®nement of
crystal structures, University of G oÈ ttingen, Germany, 1993.
9. Molecular Structure Corporation; 1993, TEXSAN, Single
K. D. M.; Philp, D. J. Chem. Soc., Perkin Trans. 2 1998, 2459.
3
26. Heck, R. F. Org. React. 1982, 27, 345.
27. Buschmann, J.; Damerius, R.; Gerhardt, R.; Lentz, D.; Luger,
3
P.; Marschall, R.; Preugschat, D.; Seppelt, K.; Simon, A. J. Am.
Chem. Soc. 1992, 114, 9465.
Crystal Structure Analysis Software, Version 1.6, MSC, 3200
Research Forest Drive, The Woodlands, TX 77381, USA.