A new route to thio- and selenosulfonates from disulfides and diselenides. Application to the synthesis of new thio- and selenoesters of triflic acid

Article abstract of DOI:10.1021/jo960619c

Alkyl and aryl trifluoromethanethiosulfonates¹ (or selenosulfonates) were prepared in one step either from alkyl and aryl sulfenyl (or selenenyl) chlorides and sodium trifluoromethanesulfinate (3) or, more generally, from disulfides (or diselenides), 3, and bromine. The second method involved trifluoromethanesulfonyl bromide as key intermediate. Benzenethiosulfonates were obtained in a similar way from disulfides, benzenesulfinate, and bromine but benzeneselenosulfonates could not be obtained by the same method from diselenides.

Full text of DOI:10.1021/jo960619c

J . Org. Chem. 1996, 61, 7545-7550
7545
A New Rou te to Th io- a n d Selen osu lfon a tes fr om Disu lfid es a n d
Diselen id es. Ap p lica tion to th e Syn th esis of New Th io- a n d
Selen oester s of Tr iflic Acid
Thierry Billard, Bernard R. Langlois,* Sylvie Large, Daniel Anker, Nathalie Roidot, and
Philippe Roure
Universite´ Claude Bernard-Lyon I, Laboratoire de Chimie Organique 3, associe´ au CNRS,
43 Bd du 11 Novembre 1918, 69622 Villeurbanne, France
Received April 2, 1996X
Alkyl and aryl trifluoromethanethiosulfonates1 (or selenosulfonates) were prepared in one step either
from alkyl and aryl sulfenyl (or selenenyl) chlorides and sodium trifluoromethanesulfinate (3) or,
more generally, from disulfides (or diselenides), 3, and bromine. The second method involved
trifluoromethanesulfonyl bromide as key intermediate. Benzenethiosulfonates were obtained in a
similar way from disulfides, benzenesulfinate, and bromine but benzeneselenosulfonates could not
be obtained by the same method from diselenides.
In tr od u ction
(CF3SO2SeCF3) has been described (from a surprising
isomerization of CF3Se(O)OSCF3)6 and only few trifluo-
romethanethiosulfonates, essentially CF3SO2SPh7 and
CF3SO2SCF3,8 have been synthesized. Another one (CF3-
SO2-S-CCl2-CO-NPhiPr) has been claimed to exhibit
herbicidal properties.9 On the other hand, apart from
their interest as generators of trifluoromethyl radicals,
trifluoromethanethiosulfonates could be also stable and
more potent sulfenylating agents than nonfluorinated
thiosulfonates,10-12 which have found attractive applica-
tions in cephem synthesis.13,14 Like their nonfluorinated
analogues,15 trifluoromethaneselenosulfonates could be
also useful tools in organic synthesis.
Some years ago, we described new trifluoromethylation
processes in which the trifluoromethyl radical was mildly
generated either by single-electron reduction of bromot-
rifluoromethane2 or by single-electron oxidation of so-
dium trifluoromethanesulfinate3 (sodium “triflinate”, a
stable salt readily obtained from CF3Br and cheap
sources of SO2•-).4 Nevertheless, these two complemen-
tary techniques, though simple and efficient, must be
applied to substrates which are not reactive under
reductive or oxidative conditions. In order to circumvent
•
such drawbacks, we looked for new sources of the CF3
radical under mild and “neutral” conditions (from a redox
point of view).
Since our previous experiments3 indicated that the
trifluoromethanesulfonyl radical CF3SO2• is very unstable
(as confirmed by further independent calculations),5 we
planned to examine the photolytic behavior of trifluo-
romethanethiosulfonates (CF3SO2SR, 1) and their seleno
analogues (CF3SO2SeR, 2), compounds in which the
trifluoromethanesulfonyl moiety is linked by weak bonds
to large atoms like sulfur or selenium. This strategy was
successful (the results will be given in future papers), but
first, we had to prepare such reagents. At the moment,
only one perfluorinated trifluoromethaneselenosulfonate
Resu lts a n d Discu ssion
Though the successful preparation of p-tolyl p-tolu-
enethiosulfonate from p-toluenesulfonic anhydride, p-
methylthiophenol, and pyridine has been claimed in the
literature,16 the more usual course of the reactions
between thiols and sulfonic anhydrides17 or sulfonyl
chlorides10,11,18 does not lead to the formation of thiosul-
fonates but to disulfides as the major products. The
reason is that thiosulfonates, in which the divalent sulfur
atom is usually more electrophilic than the hexavalent
X Abstract published in Advance ACS Abstracts, September 15, 1996.
(1) In Chemical Abstracts, alkanethiosulfonates are named alkane-
sulfonothioic acids S-alkyl (or -aryl) esters. As these compounds are
often cited in this paper, it has been chosen to keep the simpler
thiosulfonate nomenclature system.
(6) Darmadi, A.; Haas, A.; Tebbe, K. Z. Naturforsch. 1981, 36b, 426.
(7) Haszeldine, R. N.; Tewson, T. J .; Tipping, A. E. J . Fluorine Chem.
1976, 8, 101.
(2) (a)Tordeux, M.; Langlois, B.; Wakselman, C. J . Chem. Soc.,
Perkin Trans. 1 1990, 2293; (b) Eur. Pat. (to Rhoˆne-Poulenc Chimie)
298,803, 1989 [Chem. Abstr. 1989, 111, 173730b]. (c) Clavel, J . L.;
Langlois, B.; Wakselman, C; Tordeux, M. Phosphorus, Sulfur, Silicon
Relat. Elem. 1991, 59, 129. (d) Wakselman, C.; Tordeux, M.; Clavel, J .
L.; Langlois, B. J . Chem. Soc., Chem. Commun. 1991, 993. (e) Clavel,
J . L.; Langlois, B.; Nantermet, R.; Tordeux, M.; Wakselman, C. J .
Chem. Soc., Perkin Trans. 1 1992, 3371; (f) Eur. Pat. (to Rhoˆne-Poulenc
Chimie) 374,061, 1990.
(3) (a) Clavel, J . L.; Langlois, B.; Laurent, E.; Roidot, N. Phosphorus,
Sulfur, Silicon Relat. Elem. 1991, 59, 169. (b) Langlois, B.; Monte`gre,
D.; Roidot, N. J . Fluorine Chem. 1994, 68, 63. (c) Langlois, B.; Laurent,
E.; Roidot, N. Tetrahedron Lett. 1991, 32, 7525. (d) Langlois, B.;
Laurent, E.; Roidot, N. Tetrahedron Lett. 1992, 33, 1291. (e) Clavel, J .
L.; Langlois, B.; Laurent, E.; Roidot, N. (to Rhoˆne-Poulenc Chimie)
French Pat. 2,662,439, 1991.
(8) Haas, A.; Wanzke, W.; Welcman Z. Naturforsch. 1985, 40b, 32.
(9) Phillips, W. G. (to Monsanto Co.) U. S. Pat. 3,798,254, 1974
[Chem. Abstr. 1974, 80, 145787y].
(10) Hogg, D. R. In Comprehensive Organic Chemistry; Barton D.
H. R., Ollis D., Neville J ones D., Ed.; Pergamon Press: Oxford, 1979;
Vol. 3 (Sulphur, Selenium, Silicon, Boron and Organometallic Com-
pounds), p 300.
(11) Palumbo, G.; Caputo, R. Synthesis 1981, 888.
(12) (a) Trost, B. M.; Salzmann, T. N.; Hiroi, K. J . Am. Chem. Soc.
1976, 98, 4887. (b) Trost, B. M.; Massiot, G. S. Ibid. 1977, 99, 4405.
(13) Allan, R. D.; Barton, D. H. R.; Girijavallabhan, M.; Sammes,
P. G. J . Chem. Soc., Perkin Trans. 1 1974, 1456.
(14) Tanaka, H.; Sumida, S. I.; Sorajo, K.; Torii, S. J . Chem. Soc.,
Chem. Commun. 1994, 1461.
(15) Back, T. G.; Collins, S.; Vijaya Krishna, M. Can. J . Chem. 1987,
65, 38 and references cited therein.
(4) (a) Tordeux, M.; Langlois, B.; Wakselman, C. J . Org. Chem. 1989,
54, 2452; (b) Eur. Pat. 237,446 (1987) and 278,822 (1989) [Chem. Abstr.
1989, 110, 94514k].
(5) Gonbeau, D.; Guimon, N. F.; Duplantier, S.; Ollivier, J .; Pfister-
Guillouzo, G. Chem. Phys. 1989, 135, 85.
(16) Field, L. J . Am. Chem. Soc. 1952, 74, 394.
(17) Field, L.; Parsons, T. F.; Crenshaw, R. R. J . Org. Chem. 1964,
29, 918.
(18) Kice, J . L.; Rogers, T. E.; Warheit, A. C. J . Am. Chem. Soc.
1974, 96, 8020.
S0022-3263(96)00619-6 CCC: $12.00 © 1996 American Chemical Society

7546 J . Org. Chem., Vol. 61, No. 21, 1996
Billard et al.
Ta ble 1. P r ep a r a tion of Tr iflu or om eth a n eth io- a n d
-selen osu lfon a tes fr om Su lfen yl a n d Selen en yl Ch lor id es
Sch em e 1. Rea ction of Th iols w ith Tr iflic
An h yd r id e in th e P r esen ce of a Ba se
RSH + B –
(CF3SO2)2O + RS –
CF3SO2SR + RS –
RS – + BH
O
O –
CH2Cl2
–
CF3SO2SR + CF3SO3
Na+ + RY–Cl
F3C
S
F3C
S
YR + NaCl
rt
–
RSSR + CF3SO2
O
O
3
1a–e (Y = S)
2a (Y = Se)
Sch em e 2. Rea ction of Th iols w ith Tr iflic
An h yd r id e in th e Absen ce of a Ba se
(CF3SO2)2O + RSH
CF3SO2SR + RSH
CF3SO2H + RSH
2CF3S(O)SR
CF3SO2SR + CF3SO3H
CF3SO2H + RSSR
R
Y
product
reaction time
yield (%)a
Ph
Ph
Sb
Se
S
S
S
1a
2a
1b
1c
1d
1e
15 min
5 min
15 min
48 h
1 h
24 h
84
95
93
95
(96)
0
CF3S(O)SR + H2O
4-O2NC6H4
CCl3
CO2Me
C(Ph)3
CF3SSR + CF3SO2SR
one,10,18,19 react with thiols20,21 and thiolates22 as soon as
they are formed. A recent paper indicates that fair yields
of thiosulfonates can be reached, at low temperature,
from lithium 1-propenethiolate and a very large excess
of alkanesulfonyl chloride (20 equiv) since, with only 2
equiv, the corresponding disulfide is formed with an
excellent yield.23
Indeed, in our hands, thiophenol, trifluoromethane-
sulfonic anhydride, and pyridine (or sodium hydride)
failed to deliver phenyl trifluoromethanesulfonate (CF3-
SO2SPh, 1a ), even at -78 °C: only diphenyl disulfide was
obtained along with pyridinium (or sodium) triflate and
triflinate (Scheme 1).
Nevertheless, it should be noted that, in the absence
of any base, phenyl trifluoromethyl disulfide (CF3SSPh)
is the major nonvolatile product along with diphenyl
disulfide. CF3SSPh has been previously obtained in one
or two steps from very toxic reagents like trifluo-
romethanesulfenyl chloride (CF3SCl)24-26 or bis(trifluo-
romethyl) trisulfide (CF3SSSCF3).27 In our experiment,
it could result either from the reaction of thiophenol with
CF3SO2SCF3 (formed in situ by disproportionation of
trifluoromethanesulfinic acid, as reported for nonfluori-
nated sulfinic acids28) or, more probably, from the
disproportionation of the thiosulfinate CF3S(O)SPh,8
formed in situ from trifluoromethanesulfinic acid and
thiophenol (Scheme 2).
Such an observation probably precludes any triflinic
acid-based strategy for the synthesis of thio- or sele-
noesters of triflic acid.13,28,29 Likewise, the oxidation of
phenyl trifluoromethyl disulfide does not seem suited to
our purpose since it would probably deliver CF3SSO2Ph
rather than CF3SO2SPh.30,31
S
a
Isolated yields except when mentioned in parentheses (yields
from 19F NMR analysis). PhSCl prepared from thiophenol and
b
N-chlorosuccinimide.33
Then, we turned our attention to the use of sodium
triflinate (CF3SO2Na) which is now readily available.4
Silver sulfinates are known to react with sulfenyl chlo-
rides,30 as do alkaline sulfinates21 which are also able to
substitute some relatively stable areneselenenyl bro-
mides;32 sodium triflinate itself has been employed to
obtain one of the few trifluoromethanethiosulfonates
known at the moment (CF3SO2-S-CCl2-CO-NPhiPr).9
Consequently, we prepared several new trifluoro-
methanethiosulfonates (1a -d ) and one trifluoromethane-
selenosulfonate (2a ) from sodium triflinate (3) and com-
mercially available (or easily prepared) sulfenyl and
selenenyl chlorides (Table 1). The reaction occurred
rapidly at room temperature with good yields and can
be carried out in pure dichloromethane instead of the
biphasic system (CCl4/H2O) previously recommended.9
IR spectra confirmed that 1a -d are true thiosulfonates
(-S(O)2-S-) (νsym ) 1110-1120 cm-1, νasym ) 1370-1390
33
cm-1
)
and not mixed sulfinyl-sulfenyl anhydrides
(-S(O)-O-S-), in other words that sulfur is engaged
in the CF3SO2 moiety as S(VI) and not as S(IV). The
same is true for the seleno derivative 2a (νsym ) 1095
cm-1, νasym ) 1353 cm-1). Compound 2a can be isolated
after filtration and evaporation, but its shelf-life is rather
limited (<1 day). Nevertheless, as it will be reported in
a subsequent paper, it can be used in situ.
However, sulfenyl and selenenyl chlorides are not very
stable and few of them are commercially available. If
arenesulfenyl chlorides can be obtained directly from the
corresponding thiophenols,34 other ones must be prepared
by halogenation of the corresponding disulfides34 or aryl
benzyl sulfides.35 Since disulfides and diselenides can
themselves behave as sulfenylating or selenenylating
agents, we then considered the opportunity to synthesize
1 and 2 directly from 3, and these compounds which, on
the other hand, are readily available from thiols,36
(19) Kice, J . L. Int. J . Sulfur Chem., C 1971, 6, 3.
(20) Parsons, T. F.; Buckman, J . D.; Pearson, D. E.; Field, L. J . Org.
Chem. 1965, 30, 1923 and references cited therein.
(21) Weidner, J . P.; Block, S. S. J . Med. Chem. 1972, 15, 564 and
references cited therein.
(22) Kice, J . L.; Rogers, T. E. J . Am. Chem. Soc. 1974, 96, 8009 and
8015.
(23) Block, E.; Zhao, S. H. J . Org. Chem. 1992, 57, 5815.
(24) Andreades, S.; Harris, J . F., J r.; Sheppard, W. J . Org. Chem.
1964, 29, 895.
(25) Cullan, W. R.; Dhaliwal, P. S. Can. J . Chem. 1967, 45, 379.
(26) (a) Ceacareanu, D. M.; Gerstenberger, M. R. C.; Haas, A. Chem.
Ber. 1983, 116, 3325. (b) Gerstenberger, M. R. C.; Haas, A.; Wille, R.;
Yazdanbakhsch Rev. Chim. Miner. 1986, 23, 485.
(27) Munavalli, S.; Rossman, D. I.; Rohrbaugh, D. K.; Ferguson, C.
P.; Banks, H. D. J . Fluorine Chem. 1993, 60, 85.
(28) Kice, J . L.; Bowers, K. W. J . Am. Chem. Soc. 1962, 84, 605 and
2384.
(29) (a) Stirling, C. J . M. J . Chem. Soc. 1957, 3597. (b) Kice, J . L. ;
Hampton, D. C.; Fitzgerald, A. J . Org. Chem. 1965, 30, 882. (c) Kice,
J . L.; Guaraldi, G.; Vernier, C. G. J . Org. Chem. 1966, 31, 3561. (d)
Gancarz, R. A.; Kice, J . L. Tetrahedron Lett. 1980, 21, 1697; J . Org.
Chem. 1981, 46, 4899. (e) Kang, H.; Kice, J . L. J . Org. Chem. 1984,
49, 1507.
(30) Leandri, G.; Tundo, A. Ann. Chim. (Rome) 1954, 44, 63 [Chem.
Abstr. 1955, 49, 4563d].
(31) Field, L.; Ha¨rle, H.; Owen, T. C.; Ferretti, A. J . Org. Chem.
1964, 29, 1632.
(32) (a) Foss, O. J . Am. Chem. Soc. 1947, 69, 2236. (b) Austad, T.
Acta Chem. Scand. A 1976, 30, 479.
(33) Nakanishi, K. Infrared Absorption Spectroscopy; Holden-Day
Inc. and Nankodo Co. Ltd., San Francisco and Tokyo, 1962; p 54.
(34) Harpp, D. N.; Mathiaparanam, P. J . Org. Chem. 1972, 37, 1367.
(35) Ueki, M.; Honda, M.; Kazama, Y.; Katoh, T. Synthesis 1994,
21.
(36) Wallace, T. J .; Schriesheim, A.; Bartok, W. J . Org. Chem. 1963,
28, 1311.

A New Route to Thio- and Selenosulfonates
J . Org. Chem., Vol. 61, No. 21, 1996 7547
Ta ble 2. P r ep a r a tion of Tr iflu or om eth a n eth io- a n d
-selen osu lfon a tes fr om Disu lfid es a n d Diselen id es
Ta ble 3. P r ep a r a tion of Ben zen eth iosu lfon a tes fr om
Disu lfid es
O
O
O –
O –
CH2Cl2
CH2Cl2
2Ph
S
2Ph
S
SR + 2NaBr
2F3C
S
2F3C
S
YR + 2Br –
Na+ + RS–SR + Br2
+ RY–YR + Br2
rt
rt
O
O
O
O
(2 equiv)
(1 equiv) (1 equiv)
3
4a,f–k
5a
1a,f–j (Y = S)
2a (Y = Se)
6
4a,g–i
7a,g–i
R
Y
substr RYYR/Br2/3 product yield (%)a
R
substrate
product
yield (%)
Ph
Ph
Ph
4-ClC6H4
PhCH2
n-C8H17
-(CH2)2CO2Et
c-C6H11
S
S
Se
S
S
S
S
S
S
4a
4a
5a
4f
4g
4h
4i
1/1/2
1/1.5/3
1/1/2
1/1/2
1/1/2
1/1/2
1/1/2
1/1/2
1/1/2
1a
1a
2a
1f
1g
1h
1i
50
67
(55)
50
90
88
88
65
0
Ph
Ph-CH2
n-C8H17
-(CH2)2CO2Et
4a
4g
4h
7a
7g
7h
7i
70
90
60
80
4i
is consistent with the failure already reported for the
reaction of tert-butyl disulfide with sodium methanesulfi-
nate and silver nitrate.43 The latter report also specified
that, with other disulfides, the -S(O)2-S structure was
obtained rather than the -S(O)-O-S- one. In our
process too, IR spectra were in accordance with the
formation of the thiosulfonate structure only. Phenyl
trifluoromethaneselenosulfonate (2a ) has been prepared,
in the same way, from diphenyl diselenide (5a ), bromine,
and 3, but diphenyl ditelluride failed to deliver the
expected tellurosulfonate.
Such a technique is not specific for the synthesis of
trifluoromethanethiosulfonates and has been extended
to the preparation of benzenethiosulfonates from sodium
benzenesulfinate, disulfides, and bromine (Table 3).
Nevertheless, diphenyl diselenide failed to deliver phenyl
benzeneselenosulfonate under these conditions.
The order of introduction of the reagents was a crucial
parameter, as illustrated by the three following experi-
ments dealing with the preparation of octyl trifluo-
romethanethiosulfonate (1h ). In the first one, bromine
was dropped into a solution of di-n-octyl disulfide (4h )
in dichloromethane before addition of sodium triflinate:
the bromine color did not fade, even after a long time
until 3 was introduced; when 3 was then added, this color
disappeared quite instantaneously and, after 8 h of
stirring, 1h was obtained in a good yield. In the second
experiment, bromine was dropped into a solution of 4h
4j
4k
1j
1k
t-Bu
a
Isolated yields except when mentioned in parentheses (yields
from 19F NMR analysis).
thioacetates,37 thiocyanates,38 or selenocyanates,32b as
well as from alkyl halides39 or arenediazonium salts.40
Indeed, some aryl areneselenosulfonates have been
produced, very recently, by oxidation of aryl diselenides
in the presence of arenesulfinates. However, with am-
monium peroxydisulfate as oxidant,41 the technique is not
adaptable to the synthesis of 2 since peroxydisulfate
oxidizes triflinate anion to CF3.3a When [bis(trifluoro-
•
acetoxy)iodo]benzene is used,42 a 4-fold excess of sulfinate
(over diselenide) is claimed and, moreover, the large
amounts of side products (PhI, CF3CO2Na) are not in
accordance with the recent “atom economy” concept.
Concerning thiosulfonates, some have been already ob-
tained from sodium methanesulfinate and disulfides,
provided that the latter were activated with stoichiomet-
ric amounts of silver nitrate.43 In this expensive tech-
nique, only one thiyl moiety of the disulfide leads to the
desired product, the second one being lost as insoluble
silver thiolate. Thus, we examined the possibility of
activating disulfides (4) or diselenides (5) in situ by
bromine (in the form of sulfenyl bromides or bromosul-
fonium bromides) to promote their reaction with 3.
Indeed, when solutions of 3 and different disulfides
(4a ,f-k ) in dichloromethane were treated dropwise with
bromine at room temperature and then stirred at the
same temperature for 8 h, the corresponding trifluo-
romethanethiosulfonates (1a ,f-j) were obtained in fair
to good yields. Provided that a molar ratio 3/4 g 2 was
used, both thiyl moieties of the disulfide delivered the
corresponding thiosulfonate (Table 2). Aliphatic disul-
fides, which are more nucleophilic, delivered better yields
than aromatic ones. In the latter case, however, the yield
can be improved by increasing the amounts of 3 and
bromine. Primary disulfides (4g-i) were more reactive
than secondary ones (4j), and tert-butyl disulfide (4k ),
which is very hindered, failed to deliver 1k . This result
and
3
in
dichloromethane: the reaction medium remained color-
less all through this sequence and, when quenched just
after bromine addition, delivered 1h in a 50% yield.
When treatment was carried out after 8 h of stirring at
room temperature, 1h was isolated in 88% yield. In the
third experiment, bromine was first added to a suspen-
sion of 3 in dichloromethane: the bromine color was
discharged immediately upon addition. Then, 4h was
added and, after stirring as long as previously, 1h was
obtained in the same yield. The same result was
obtained when pure trifluoromethanesulfonyl bromide
(8), previously prepared from bromine and an aqueous
solution of 3,44 was treated with 4h .
The same observations have been made during the
preparation of phenyl benzenethiosulfonate (7a ): this
compound was obtained in the same yield either by
addition of bromine to a mixture of 6 and 4a or when
bromine was added dropwise to 6 followed by the addition
of 4a to the colorless resulting mixture.
(37) Choi, J .; Yoon, N. M. Synlett 1995, 1073.
(38) (a) Giffard, M.; Buisson, J . P.; Busnel, J . P.; Godon, C.; Lefrant,
S.; Nguyen, T. P. J . Chem. Res. (S) 1993, 126. (b) J ia, X.; Zhang, Y.;
Zhou, X. Tetrahedron Lett. 1994, 35, 8833. (c) Prabhu, K. R.; Ramesha,
A. R.; Chandrasekaran, S. J . Org. Chem. 1995, 60, 7142.
(39) Ramesha, A. R.; Chandrasekaran, S. Synth. Commun. 1992,
22, 3277.
(40) Bhar, D.; Chandrasekaran, S. Synthesis 1994, 785.
(41) Wang, L.; Huang, X. Synth. Commun. 1993, 23, 2817.
(42) Chen, D. W.; Chen, Z. C. Tetrahedron Lett. 1994, 35, 7637.
(43) Bentley, M. D.; Douglass, I. B.; Lacadie, J . A. J . Org. Chem.
1972, 37, 333.
(44) Forat, G. Private communication: bromine reacts very rapidly
with an aqueous solution of 3 at room temperature and liquid 8
separates quite pure; it can be purified by distillation (bp 53 °C/760
mmHg).

7548 J . Org. Chem., Vol. 61, No. 21, 1996
Sch em e 3. Rea ction P a th w a ys fr om Disu lfid es (or Diselen id es), 3, a n d Br om in e
Billard et al.
step 1
O –
O
O
R′
S
+ Br2
+ Br –
S
R′
Br
O
3 (R′ = CF3)
6 (R′ = Ph)
8 (R′ = CF3)
9 (R′ = Ph)
step 2
Br
Y
O –
O
path 1
+
R′
S
R
R′ = CF3
Y
R
O
O
O
Y
Y
8 or 9 + RY–YR
+
R
S
R
Br
R′
–O
R′
R
4 (Y = S)
5 (Y = Se)
path 2
1 (R′ = CF3, Y = S)
2 (R′ = CF3, Y = Se)
7 (R′ = Ph, Y = S)
S
R′ = Ph
Br
Y
+
Y
R
step 3
R′
O
O
Y
O –
O
Y
+ Br –
R
S
+
S
Br
R
R′
1 (R′ = CF3, Y = S)
2 (R′ = CF3, Y = Se)
7 (R′ = Ph, Y = S)
3 (R′ = CF3)
6 (R′ = Ph)
These experiments clearly demonstrated that 8 or
benzenesulfonyl bromide (9) was the true reactive species
and was formed more rapidly than sulfenyl bromides.
Moreover, when taking into account the excellent yields
of 1g and 7g resulting from dibenzyl disulfide (4g), it is
suspected that bromine did not react with disulfides to
a large extent since halogenation of 4g is known to
deliver benzyl halides rather than phenylmethanesulfe-
nyl halides.45 Concerning the reaction mechanism
(Scheme 3), it can be suggested that 8 and 9, which were
obviously formed first in a very fast reaction from 3 and
6 (step 1), reacted rapidly with disulfides 4 (or diselenides
5) to provide 1 (or 2) and 7 along with sulfenyl bromides
(or selenenyl bromides) (step 2). Then, the latter were
substituted by 3 and 6 in a slow reaction (step 3); this
proposal is consistent with the amount of 1h (yield )
50%) obtained just after the introduction of bromine.
More precisely, 4 can attack 8 or 9, during the second
step, either at the bromine atom (path 1) or at the sulfur
atom (path 2); these two routes lead to the same products.
However, it can be suspected that 8, which probably
behaves as a strong electrophilic brominating agent like
other perfluoroalkanesulfonyl bromides,46 reacts more
easily through path 1 whereas 9, in which sulfur consti-
tutes the most electrophilic center, probably reacts es-
sentially through path 2. Such a difference could explain
why the bulky diphenyl diselenide delivers 2a through
path 1 but does not react, through path 2, with 9.
Concerning the third step, it can be understood that the
reaction of sulfinates 3 and 6 with sulfenyl bromides is
a slow process because these intermediates are electro-
meric compounds in which the S-Br bond is not very
cleanly polarized47 (except when electron-withdrawing
groups are present).32
the expected thiosulfonate 1l was detected in low yield
along with several byproducts. It could be suspected that
the sulfonium species resulting from the reaction of 4l
and 8 deprotonated very easily and provided very reactive
unsaturated products.
Con clu sion
Thiosulfonates can be prepared at room temperature
by an efficient, inexpensive, and easy to scale-up route,
from sulfinates, disulfides, and bromine. Usually, sele-
nosulfonates cannot be obtained by the same technique.
However, with sodium trifluoromethanesulfinate and
bromine, both disulfides and diselenides provide the
corresponding chalcogenosulfonates, quite unknown at
present. Some of these compounds can be also obtained
from sulfenyl or selenenyl chlorides and sodium trifluo-
romethanesulfinate, but the scope of this method is not
so wide. Such a simple access to new compounds il-
lustrates the importance of now readily available sodium
triflinate in fluorine chemistry. Our experiments, pres-
ently in progress, with thio- and selenoesters of triflic
acid show that these compounds are very versatile and
fruitful tools; they behave as precursors of the very
lipophilic trifluoromethylthio and trifluoromethylseleno
ethers, provide easily vinyl trifluoromethyl sulfones, and
also allow the formal vicinal addition of trifluoromethyl
and thiyl moieties to olefins. The results will be reported
in future papers.
Exp er im en ta l Section
Dichloromethane was distilled prior to use and stored over
3 Å molecular sieves. Other reagents were used as received.
1
Unless stated otherwise, H, 19F, and 13C NMR spectra were
The occurrence of sulfonium intermediates (step 2)
could also explain why diethyl 2,2′-dithiodiacetate (4l, R
) CH2CO2Et) did not react cleanly with 3 and bromine:
recorded in CDCl3 at 200, 188, and 50 MHz, respectively.
Chemical shifts are given in ppm relative to TMS (1H, 13C) or
CFCl3 (19F) used as internal references. Coupling constants
are given in hertz. UV absorptions were determined in
acetonitrile in a 1 cm long cell. IR spectra were recorded either
on the pure compound (in KBr) or by a coupled GC-IR FT
technique. Frequencies are given in cm-1. Mass spectra were
recorded at 70 eV.
(45) Douglass, I. B.; Brower, K. R.; Martin, F. T. J . Am. Chem. Soc.
1952, 74, 5770.
(46) Huang, W. Y.; Chen, J . L.; Hu, L. Q. Bull. Soc. Chim. Fr. 1986,
881.
(47) Ku¨hle, E. Synthesis 1971, 563 and references cited therein.

A New Route to Thio- and Selenosulfonates
J . Org. Chem., Vol. 61, No. 21, 1996 7549
Ta ble 4. Sp ectr oscop ic F ea tu r es of CF 3SO2SR (1a -d ,f-j) a n d CF 3SO2SeP h (2a )
NMR data
13C NMR
UV data
ꢀ (L mol-1 cm-1
)
CF3SO2YR
1 (Y) S) or 2 (Y) Se)
CF3 (quadruplet)
δ(ppm), J C-F (Hz)
19F NMR δ (ppm)
-75.80
SO2-Y-C δ (ppm)
λ
max (nm)
1a (R ) Ph)
120.11, 330.0
124.57
200.0
238.2
22325
10930
1b (R ) 4-O2NC6H4)
1c (R ) CCl3)
-75.32
-75.20
-75.95
-75.46
-78.64
-78.96
120.00, 329.7
119.36, 330.0
119.30, 329.5a
120.06, 330.0
119.68, 327.9
119.65, 327.7
131.80
93.39
1d (R ) CO2Me)
1f (R ) 4-ClC6H4)
1g (R ) PhCH2)
158.73a
122.94
132.12
37.97
1h (R ) n-C8H17
)
193.4
239.3
194.5
237.0
192.0
239.2
200.1
243.8
2105
105
2812
625
1917
94
12217
7195
1i (R ) (CH2)2CO2Et)
-78.95
-79.25
-77.60
119.58, 327.6
119.52, 327.7
118.63, 332.0
34.49
53.72
1j (R ) c-C6H11
2a (R ) Ph)
)
125.41
a
From a preparation performed in CDCl3.
Reaction of Tr iflu or om eth an esu lfon ic An h ydr ide with
Th iop h en ol. Degased dichloromethane (3 mL) was placed
in a flask and kept under nitrogen; then triflic anhydride (1.69
g, 6 mmol) was added, followed by thiophenol (0.66 g, 6 mmol)
which was introduced dropwise. After being stirred at room
temperature for 24 h, the reaction was washed with water and
the aqueous phase extracted with ether. The gathered organic
phases were dried over magnesium sulfate. After filtration
and evaporation under reduced pressure, the crude mixture
was analyzed by GC-MS and NMR 19F (with (trifluoromethoxy)-
benzene as internal standard). The estimated crude yield of
phenyl trifluoromethyl disulfide was 25%.
13C NMR: δ 136.88, 132.81, 130.06, 124.57, 120.11 (q, J )
330.0). MS: m/ z 242 (M•+), 109, 69. IR FT: (KBr) 3088, 1370,
1204, 1106, 763, 689, 620; (GC-IRFT) 3076, 1393, 1215, 1119,
744, 687. Anal. Calcd for C7H5F3O2S2: C, 34.71; H, 2.07; S,
26.45. Found: C, 34.71; H, 2.17; S, 26.26.
4-Nit r op h en yl Tr iflu or om et h a n et h iosu lfon a t e (1b ).
Mp: 76-77 °C. 1H NMR: δ 8.39-8.32 (m, 2H), 7.95-7.88 (m,
2H). 13C NMR: δ 150.25, 137.59, 131.80, 124.79, 120.00 (q, J
) 329.7). MS: m/ z 287 (M•+), 154, 108, 69, 30. Anal. Calcd
for C7H4F3NO4S2: C, 29.27; H, 1.39; N, 4.88; S, 22.3. Found:
C, 29.42; H, 1.34; N, 4.95; S, 21.75.
Tr ich lor om eth yl Tr iflu or om eth a n eth iosu lfon a te (1c).
Oil. 13C NMR (75 MHz): δ 119.36 (q, J ) 330.0), 93.39. MS:
m/ z 282 (M•+), 247, 151, 117, 79, 69.
P h en yl Tr iflu or om eth yl Disu fid e. 19F NMR: δ -46.37.
MS: m/ z 210 (M•+), 141, 109, 77, 69.
Gen er a l P r oced u r e for t h e Syn t h esis of Tr iflu o-
r om eth a n eth iosu lfon a tes (or Selen osu lfon a tes) fr om 3
a n d Su lfen yl (or Selen en yl) Ch lor id es. A solution of the
selected sulfenyl or selenenyl chloride (around 1 mmol) in
dichloromethane was dropped, at room temperature, in ap-
proximately 5 min on a suspension of 3 (1 molar equiv) in
dichloromethane. The resulting mixture was then stirred at
room temperature and its composition followed by GC. After
the time indicated in Table 1, the reaction medium was filtered
and the filtrate evaporated at room temperature under reduced
pressure. The crude thio- or selenosulfonates were usually
sufficiently pure to be used in further reactions. They cannot
be submitted to column chromatography but can be purified
by distillation or recrystallization from petroleum ether.
Gen er a l P r oced u r e for t h e Syn t h esis of Tr iflu o-
r om eth a n eth iosu lfon a tes (or Selen osu lfon a tes) fr om 3,
Br om in e, a n d Disu lfid es (or Diselen id es). The selected
disulfide or diselenide (around 1 mmol) was added to a
suspension of 3 in dichloromethane. Then, a 1 M solution of
bromine in dichloromethane was added dropwise at room
temperature, over approximately 5 min, at a rate which
allowed the medium to remain colorless. The amounts of 3
and bromine, which can vary with the substrate, are indicated
in Table 2, but usually, 2 molar equiv of 3 and 1 of bromine
were used. Then, the resulting mixture was stirred at room
temperature and its composition followed by GC. When a
stable composition was reached (usually after 8 h), the reaction
medium was filtered and the filtrate evaporated at room
temperature under reduced pressure. The crude thio- or
selenosulfonate was purified by distillation under reduced
pressure or recrystallization in petroleum ether.
Meth oxycar bon yl Tr iflu or om eth an eth iosu lfon ate (1d).
1H NMR (300 MHz): δ 4.04 (s). 13C NMR (75 MHz): δ 158.73,
119.30 (q, J ) 329.5), 57.3. Decomposition on GC columns.
4-Ch lor op h en yl Tr iflu or om eth a n eth iosu lfon a te (1f).
Oil. 13C NMR: δ 139.95, 137.98, 130.43, 122.94, 120.06 (q, J
) 330.0). MS: m/ z 278 and 276 (M•+), 145 and 143, 108, 69.
Anal. Calcd for C7H4ClF3O2S2: C, 30.38; H, 1.45; Cl, 12.84;
S, 23.15. Found: C, 30.13; H, 1.37; Cl, 12.94; S, 23.03.
Ben zyl Tr iflu or om eth a n eth iosu lfon a te (1g). Oil. 1H
NMR: δ 7.36 (s, 5H), 4.5 (s, 2H). 13C NMR: δ 132.12, 129.46,
129.34, 129.10, 119.68 (q, J ) 327.9), 41.99. MS: m/ z 256
(M•+), 123, 122, 91. Anal. Calcd for C8H7F3O2S2: C, 37.50;
H, 2.73; S, 25.0. Found: C, 37.92; H, 2.74; S, 25.35.
n -Octyl Tr iflu or om eth a n eth iosu lfon a te (1h ). Oil. 1H
NMR: δ 3.28 (t, J ) 7.35, 2H), 1.79 (quint, J ) 7.35 and 7.50,
2H), 1.28 (m, 10H), 0.89 (t, J ) 6.5, 3H). 13C NMR: δ 119.65
(q, J ) 327.7), 37.97, 31.78, 29.28, 29.07, 28.90, 28.43, 22.69,
14.09. MS: m/ z 221 (M - C4H9), 145, 69. IR: 2980, 2930,
2880, 1460, 1370, 1210, 1110, 740, 630. Anal. Calcd for
C9H17F3O2S2: C, 38.85; H, 6.11; S, 23.02. Found: C, 38.72;
H, 6.11; S, 23.11.
E t h yl 3-((Tr iflu or om et h a n esu lfon yl)t h io)p r op ion a t e
(1i). Oil. 1H NMR: δ 4.20 (q, J ) 7.16, 2H), 3.48 (t, J ) 6.41,
2H), 2.89 (t, J ) 6.41, 2H), 1.29 (t, J ) 7.16). 13C NMR: δ
170.78, 119.58 (q, J ) 327.6), 61.64, 34.49, 32.77, 14.15. MS:
m/ z 221 (M - OEt), 193, 133, 105, 69, 45, 29. IR: 1730, 1370,
1210, 1110, 620. Anal. Calcd for C6H9F3O4S2: C, 27.07; H,
3.38; S, 24.06. Found: C, 27.09; H, 3.56; S, 23.09.
Cycloh exyl Tr iflu or om eth a n eth iosu lfon a te (1j). Oil.
1H NMR (300 MHz): δ 3.69 (tt, J ) 10 and 4, 1H), 2.15 (m,
2H), 1.9-1.1 (m, 8H). 13C NMR: δ 119.52 (q, J ) 327.7), 53.72,
33.94, 25.77, 24.89. MS: m/ z 248 (M•+), 179, 83. Anal. Calcd
for C7H11F3O2S2: C, 33.86; H, 4.47; S, 25.83. Found: C, 34.13;
H, 4.51; S, 25.09.
The same procedure was used to prepare benzenethiosul-
fonates.
Com m on Sp ectr oscop ic F ea tu r es of CF 3SO2SR (1a -
d , f-j) a n d CF 3SO2SeP h (2a ). See Table 4.
Ad d it ion a l Da t a for CF 3SO2SR (1a -d ,f-j) a n d
CF 3SO2SeP h (2a ). P h en yl Tr iflu or om et h a n et h iosu l-
fon a te (1a ). Mp: 38-39 °C. 1H NMR: δ 7.73-7.45 (m, 5H).
P h en yl Tr iflu or om eth a n eselen osu lfon a te (2a ). Mp:
61-64 °C dec. 1H NMR (300 MHz): δ 7.79-7.76 (m, 2H),
7.58-7.43 (m, 3H). 13C NMR: δ 137.44, 132.33, 130.10,

7550 J . Org. Chem., Vol. 61, No. 21, 1996
Billard et al.
125.41, 118.63 (q, J ) 332.0). IR FT (KBr) 2930, 1353, 1179,
1095, 758, 688, 614. Not stable enough for GC and elemental
analysis.
1.58 (quint, J ) 7.3, 2H), 1.20 (m, 10H), 0.86 (t, J ) 6.8, 3H).
13C NMR: δ 144.93, 133.62, 129.29, 126.94, 36.15, 31.70, 28.99,
28.85, 28.58, 28.50, 22.61, 14.10. MS: m/ z 287 (M + 1), 145,
125, 77. Anal. Calcd for C14H22O2S2: C, 58.74; H, 7.69; S,
22.38. Found: C, 58.64; H, 7.76; S, 22.50.
Ch a r a cter istics of Ben zen eth iosu lfon a tes Men tion ed
in Ta ble 3. P h en yl Ben zen eth iosu lfon a te (7a ). Mp: 40-
41 °C (lit. mp 43-44.5 °C,48 44.5-45.5 °C 16). 1H NMR: δ
7.63-7.28 (m). 13C NMR: δ 142.83, 136.50, 133.72, 131.47,
129.50, 128.80, 127.73, 127.50. MS: m/ z 250 (M•+), 141, 109,
77.
Eth yl 3-(Ben zen esu lfon ylth io)p r op ion a te (7i). Oil. 1H
NMR: δ 7.98-7.92 (m, 2H), 7.66-7.53 (m, 3H), 4.12 (q, J )
7.13, 2H), 3.20 (t, J ) 6.94, 2H), 2.71 (t, J ) 6.94, 2H), 1.23 (t,
J ) 7.13, 3H). 13C NMR: δ 170.9, 144.5, 133.5, 129.4, 126.9,
61.0, 34.2, 30.7, 14.1. MS: m/ z 229 (M - OEt), 133, 77. Anal.
Calcd for C12H10O2S2: C, 48.17; H, 5.11; S, 23.36. Found: C,
47.81; H, 5.10; S, 23.22.
Ben zyl Ben zen eth iosu lfon a te (7g). Oil. 1H NMR:
δ
7.81-7.77 (m, 2H), 7.53-7.37 (m, 3H), 7.26-7.09 (m, 5H), 4.22
(s, 2H). 13C NMR: δ 144.67, 133.52, 133.49, 129.12, 128.96,
128.67, 127.92, 126.70, 40.28. MS: m/ z 264 (M•+), 123, 91,
77.
Ack n ow led gm en t. The authors are very grateful to
the Rhoˆne-Poulenc Co. for a generous gift of sodium
triflinate.
n -Octyl Ben zen eth iosu lfon a te (7h ). Oil. 1H NMR: δ
7.96-7.93 (m, 2H), 7.91-7.50 (m, 2H), 2.99 (t, J ) 7.3, 2H),
(48) Kice, J . L.; Rogers, T. E. J . Am. Chem. Soc. 1974, 96, 8095.
J O960619C