Sulfenyl chloride chemistry. New precursors for diatomic sulfur transfer

Article abstract of DOI:10.1021/jo9710792

When triphenylmethanesulfenyl chloride (1) (or its thio homologue 2) are treated with various bicycles, norbornene (5), or bicyclo[2.2.2]octene (6), dithio adducts 7 and 8 were produced in good isolated yields. Final products were obtained via an episulfide intermediate. The stereochemistry of addition has been determined by X-ray analysis. Treatment of thiosulfenyl chloride 2 (or its dithio homologue 3) with other olefins, cyclopentene (10), cyclohexene (11), or 1,4-dioxene (12), leads to the formation of disulfides (13-15 from 2) and trisulfides (16 and 17 from 3) in high isolated yields (ca. 92%). The structures of 7, 8, and 13-17 were established by ¹H and ¹³C NMR and elemental analysis as well as by X-ray determination. When these adducts are warmed with a 1,3-diene 42, they deliver diatomic sulfur- trapped derivatives, cyclic di-49 and tetrasulfide adducts 46. A variety of solvents, temperatures, times, and concentrations were employed to optimize the yield of 46 and 49. The tetrasulfide adduct 46 is quantitatively converted to disulfide 49 with triphenylphosphine; this affords cyclic disulfides in > 50% isolated yield from the diene. In addition, evidence has been obtained implicating dithietane intermediate 4.

Full text of DOI:10.1021/jo9710792

8654
J . Org. Chem. 1998, 63, 8654-8660
Su lfen yl Ch lor id e Ch em istr y. New P r ecu r sor s for Dia tom ic Su lfu r
Tr a n sfer
Imad A. Abu-Yousef and David N. Harpp*
Department of Chemistry, McGill University, Montre´al, Que´bec, Canada H3A 2K6
Received J une 16, 1997
When triphenylmethanesulfenyl chloride (1) (or its thio homologue 2) are treated with various
bicycles, norbornene (5), or bicyclo[2.2.2]octene (6), dithio adducts 7 and 8 were produced in good
isolated yields. Final products were obtained via an episulfide intermediate. The stereochemistry
of addition has been determined by X-ray analysis. Treatment of thiosulfenyl chloride 2 (or its
dithio homologue 3) with other olefins, cyclopentene (10), cyclohexene (11), or 1,4-dioxene (12),
leads to the formation of disulfides (13-15 from 2) and trisulfides (16 and 17 from 3) in high
1
isolated yields (ca. 92%). The structures of 7, 8, and 13-17 were established by H and 13C NMR
and elemental analysis as well as by X-ray determination. When these adducts are warmed with
a 1,3-diene 42, they deliver diatomic sulfur-trapped derivatives, cyclic di-49 and tetrasulfide adducts
46. A variety of solvents, temperatures, times, and concentrations were employed to optimize the
yield of 46 and 49. The tetrasulfide adduct 46 is quantitatively converted to disulfide 49 with
triphenylphosphine; this affords cyclic disulfides in >50% isolated yield from the diene. In addition,
evidence has been obtained implicating dithietane intermediate 4.
In tr od u ction
1,3-dienes affords a 1,4-addition product, which subse-
quently produces cyclic di- and tetrasulfides in good
overall yield. The net effect of the latter transformation
is to deliver a 2- and 4-sulfur fragment to the diene.
We have initiated a study of some of the chemistry of
this type of addition for the preparation of a new series
of di- and trisulfides hoping that these reagents can be
used to develop a useful pathway to dithietanes 4 as
potentially stable intermediates and/or diatomic sulfur
precursors.
The chemistry of sulfenyl halides has been extensively
studied.1 The reaction of sulfenyl halides with olefins has
been interpreted mechanistically in terms of the forma-
tion of an episulfonium ion intermediate2 that is inter-
cepted by a halide ion to form a â-halo thioether. The
chemistry of triphenylmethanesulfenyl chloride (1) and
its thio (2) and dithio (3) homologues is much less
examined.3
The reaction of triphenylmethanesulfenyl chloride (1)
with norbornene has been investigated previously.4 In-
deed, other similar types of sulfenyl halides have been
shown to add to carbon-carbon double bonds; this has
resulted in preparative methods for episulfides.5
In the case of the reaction of sulfenyl chloride 1 with
norbornene, a number of products were reported,4 but
details were lacking, and neither their stereochemistry
nor the mechanism of the reaction was demonstrated.
Recently, we6 investigated an interesting reaction of
triphenylmethanesulfenyl chloride (1) where its sulfur
atom is extruded quantitatively and catalytically by a
reaction with thioketones. In another study,7 the reac-
tion of triphenylmethanethiosulfenyl chloride (2) with
Resu lts a n d Discu ssion
An equimolar amount of triphenylmethanesulfenyl
chloride (1) was reacted with bicyclo[2.2.1]heptene (5)
or bicyclo[2.2.2]octene (6) at room temperature under a
nitrogen atmosphere. endo-2-Chloro-exo-1-(triphenyl-
methyldithio)bicyclo[2.2.1]heptane (7) and endo-2-chloro-
exo-1-(triphenylmethyldithio)bicyclo[2.2.2]octane (8) were
produced, respectively, in good isolated yields (ca. 47%).
Dithio adducts 7 and 8 where obtained in a high yield
(ca. 92%) when 2 mol ratio of sulfenyl chloride 1 was
used.
(1) Gundermann, K. D. Angew Chem., Int. Ed. Engl. 1963, 2, 674.
Harstaff, W. R.; Langler; R. F. Sulfur in Organic and Inorganic
Chemistry; Senning, A., Ed.; Marcel Dekker: New York, 1982; Vol. 4,
p 193. Schmit, G. H.; Garrat, D. G. The Chemistry of the Double Bonded
Functional Groups; Patai, S., Ed.; J ohn Wiley & Sons: New York, 1982,
Chapter 9.
(2) Ku¨hle, E. Synthesis 1970, 561.
(3) Harpp, D. N.; Ash, D. K. Int. J . Sulfur Chem., A 1971, 1, 211.
(4) Majewski, J . M.; Zakrzewski, J . Tetrahedron Lett. 1981, 22, 3659.
(5) (a) Fujisawa, T.; Kobori, T. Chem. Lett. 1972, 1065. (b) Fujisawa,
T.; Kobori, T. Chem. Lett. 1972, 935. (c) Bombala, M. U.; Ley, S. V. J .
Chem. Soc., Perkin Trans. 1 1979, 3013.
(6) Williams, C. R.; Harpp, D. N. Tetrahedron Lett. 1991, 32, 7633.
(7) Williams, C. R.; Harpp, D. N. Tetrahedron Lett. 1991, 32, 7651.
The identity of these adducts 7 and 8 was confirmed
1
by H and 13C NMR and elemental analysis as well as
by X-ray analysis. The X-ray crystallographic structures
10.1021/jo9710792 CCC: $15.00 © 1998 American Chemical Society
Published on Web 11/06/1998

Sulfenyl Chloride Chemistry
Sch em e 1
J . Org. Chem., Vol. 63, No. 24, 1998 8655
to tetramethylsilane of the disulfide adducts are reported
in Table 2 of the Supporting Information.We also found
that treatment of cyclopentene (10) and cyclohexene (11)
with triphenylmethanedithiosulfenyl chloride (3) at room
temperature under a nitrogen atmosphere leads to the
formation of trans-2-chloro-1-(triphenylmethyltrithio)-
cyclopentane (16) and trans-2-chloro-1-(triphenylmeth-
yltrithio)cyclohexane (17), respectively, in high isolated
yields (ca. 94%).
The identity of trisulfides 16 and 17 was confirmed by
1H and 13C NMR and elemental analysis as well as by
X-ray determination. The X-ray crystallographic struc-
tures of 16 and 17 were reported10 for the first time.
Selected bond lengths and angles are shown in Table 3
of the Supporting Information.9
The assignments of relevant 13C NMR chemical shifts
relative to tetramethylsilane of trithio adducts are re-
ported in Table 4 of the Supporting Information. In
addition, we investigated the reaction of triphenyl-
methanesulfenyl chloride (1) and its thio (2) and dithio
(3) homologues with more hindered olefins such as
adamantylideneadamantane (18) and bicyclo[3.3.1]non-
ylidenebicyclo[3.3.1]nonane (19).
of 7 and 8 were reported8 for the first time. Selected bond
lengths and angles are shown in Table 1 of the Support-
ing Information.9
The analysis revealed that the regiochemistry of 7 and
the symmetry of 8 permits only one isomer. The addition
products 7 and 8 contained two sulfur atoms rather than
one. A plausible mechanism showing the explanation for
the presence of the second sulfur atom is indicated by
the pathway in Scheme 1.
To demonstrate the likelihood of this mechanism, we
independently prepared exo-episulfide 95c and treated it
with triphenylmethanesulfenyl chloride (1). Dithio 7 was
isolated in 90% yield; this gives clear support to pathway
displayed in Scheme 1.
In the same manner, we found that triphenylmethane-
thiosulfenyl chloride (2) reacted with bicyclo[2.2.1]-
heptene (5), bicyclo[2.2.2]octene (6), cyclopentene(10),
cyclohexene (11), and 1,4-dioxene (12) at room temper-
ature under a nitrogen atmosphere. Dithio adducts 7 and
8 and trans-2-chloro-1-(triphenylmethyldithio)cyclopen-
tane (13), trans-2-chloro-1-(triphenylmethyldithio)cyclo-
hexane (14), and trans-2-chloro-3-(triphenylmethyldithio)-
1,4-dioxane (15) were formed, respectively, in high
isolated yields (ca. 92%).
1,2-Addition products such as 7 and 8 were not
isolated; instead, cyclization takes place forming the
corresponding episulfides adamantylideneadamantane-
thiirane (20)11 and bicyclo[3.3.1]nonylidenebicyclo[3.3.1]-
nonanethiirane (21),11b,12 respectively.
We also studied the reaction of triphenylmethanesul-
fenyl chloride (1) and its thio (2) and dithio (3) homo-
logues with another series of olefins. Cyclic olefins such
as 1,2-diphenylcyclohexene (22), 1,2-diphenylcyclobutene
(23), 1,4-dimethylcyclohexene (24), (1R)-(+)-R-pinene
(25), (1S)-(-)-â-pinene (26), 3-carene (27), 2-carene (28),
camphene (29), 3,4-dihydro-2H-pyran (30), 2,5-dihydro-
furan (31), and 2,5-dimethoxy-2,5-dihydrofuran (32) did
not react with the series of sulfenyl chlorides, 1-3.
The structures of these adducts were established by
1H and 13C NMR as well as by elemental analysis. The
assignments of relevant 13C NMR chemical shifts relative
(10) Abu-Yousef, I. A.; Hynes, R. C.; Harpp, D. N. Tetrahedron Lett.
1993, 34, 7167.
(8) Abu-Yousef, I. A.; Hynes, R. C.; Harpp, D. N. Tetrahedron Lett.
1993, 34, 4289.
(9) J ohnson, C. K. ORTEP-A Fortran Thermal Ellipsoid Plot Pro-
gram; Technical Report ORNL-5138; Oak Ridge National Laborato-
ries: Oak Ridge, TN, 1976.
(11) (a) Abu-Yousef, I. A.; Harpp, D. N. Tetrahedron Lett. 1995, 36,
201. (b) Abu-Yousef, I. A.; Harpp, D. N. Sulfur Rep. 1997, 20, 1.
(12) Abu-Yousef, I. A.; Harpp, D. N. New Sulfenyl Chloride Chem-
istry. Stable Precursors For Sulfur Monoxide Transfer; 25th Canadian
Chemical Conference, Guelph, Ontario, Canada, J une, 1995.

8656 J . Org. Chem., Vol. 63, No. 24, 1998
Abu-Yousef and Harpp
procedures13a,d that require the use of compound 43 are
difficult. In addition, the triarylmetal trisulfides 4413a
are not easy to prepare.
The major limitation in case of the procedure of
Steliou13c is that it must be conducted in the absence of
most functionalities. The major sulfurating reagent,
hexamethyldisilthiane, which was used in his procedure14
to produce S2, uses a method for the conversion of ketones
to thioketones. The disilthiane readily reacts with
moisture to produce hydrogen sulfide (H2S). In addition,
boron trichloride is a strong Lewis acid and readily
complexes with oxygen or other donor atoms to hamper
S2 formation. In the case of the procedure of Schmidt
and Go¨rl,13b the major limitation is the difficulty in the
preparation of 5,5-dimethyl-1,2-dithia-3,7-diselenacyclo-
heptane (45). The production of the cyclic tetrasulfide
adduct 1,2,3,4-tetrathia-6,7-dimethyl-6-cyclooctene (46)
from the reaction of S2 with dienes has been indicated in
several instances.13d,e,f,15,17a
In addition, acyclic olefins such as 1,1,2,2-tetrameth-
ylethylene (33), 1,1,2,2-tetraphenylethylene (34), 1,1,2,2-
tetracyanoethylene (35), trans-stilbene (36), cis-stilbene
(37), 1-bromo-2-methylpropene (38), styrene (39), bro-
mostyrene (40), and vinylcyclohexane (41) were also
tried.
Nicolaou15 isolated the corresponding cyclic tetrasulfide
in the reaction of dithiatopazine 47 with 2,3-diphenyl-
1,3-butadiene.
We discovered that olefins 22-41 remained unaffected
even if the reactions were carried out over a few weeks.
This behavior can be explained by the fact that the
reaction must take place at room temperature because
sulfenyl chlorides 1-3 decomposed upon heating, and
most of the olefins are stable to addition chemistry, either
due to conjugation or because they are vinyl halides.
Tr a p p in g of Dia tom ic Su lfu r (S2). We found that
when each of the 1,2-addition products 7, 8, or 13-17
were decomposed in the presence of 2,3-dimethyl-1,3-
butadiene (42), evidence was obtained of the trapping of
diatomic sulfur.
In the literature, there are several reaction systems
reported that successfully generate diatomic sulfur in
synthetically useful yields.13 These methods have certain
limitations. For example, since triphenylphosphine di-
bromide (43) is light and moisture sensitive as well as
reactive toward a wide variety of functionalities, the two
Most recently, Harpp and co-workers13e isolated cyclic
di- and tetrasulfide adducts 46 and 49 from the thermal
decomposition of alkoxydisulfide 50 with 42 in good yield.
One important theme of this work was to try to trap
S2 in the thermal decomposition of di- and trithio adducts
7, 8, and 13-17. These in turn might decompose to
species such as dithietane intermediate 4, which should
then transfer S2 directly to dienes or lose S2, which is
then captured by dienes.
The successful identification of trapped S2 was realized
1
by H NMR in the observation of cyclic disulfide 49 and
tetrasulfide 46. This took place when the decomposition
of the 1,2-addition products 7, 8, and 13-17 was con-
ducted in the presence of 2,3-dimethyl-1,3-butadiene (42).
Once these adducts were identified, the reaction condi-
tions were modified so that the yield of the trapped
adducts 49 and 46 was maximized.
(13) (a) Steliou, K.; Gareau, Y.; Harpp, D. N. J . Am. Chem. Soc.
1984, 106, 799. (b) Schmidt, M.; Go¨rl, U. Angew. Chem., Int. Ed. Engl.
1987, 26, 887. (c) Steliou, K.; Salama, P.; Brodeur, D.; Gareau, Y J .
Am. Chem. Soc. 1987, 109, 926. (d) Harpp, D. N.; McDonald, J . G. J .
Org. Chem. 1988, 53, 3812. (e) Tardif, S.; Williams, C. R.; Harpp, D.
N. J . Am. Chem. Soc. 1995, 117, 9067. (f) These methods as well as
others are summarized in the following articles: Harpp, D. N. The
Sulfur Diatomics. Phosphorus, Sulfur and Silicon 1997, 120 & 121,
41-59. Tardif, S. L.; Rys, A. Z.; Abrams, C. B.; Abu-Yousef, I. A.; Leste-
Lasserre, P. B. F.; Schultz, E. K. V.; Harpp, D. N. Tetrahedron 1997,
53, 12225-12236.
(14) Steliou, K.; Mrani, M. J . Am. Chem. Soc. 1982, 104, 3104.
(15) Nicolaou, K. C.; Hwang, C.-K.; Duggan, M. E.; Carroll, P. J . J .
Am. Chem. Soc. 1987, 109, 3801.

Sulfenyl Chloride Chemistry
Sch em e 2
J . Org. Chem., Vol. 63, No. 24, 1998 8657
Sch em e 3
The general procedure used for the reaction of 7, 8,
and 13-17 with 2,3-dimethyl-1,3-butadiene (42) is as
follows. A solution of diene 42 and 7, 8, and 13-17 in
an appropriate solvent was refluxed for a certain time
under a nitrogen atmosphere. The reaction was followed
by thin-layer chromatography using 15-25% chloroform
in hexane as the eluent. In each case, cyclic disulfide
49 was detected by 1H NMR in low yield and cyclic
tetrasulfide adduct 46 was isolated in good yield. Their
Ta ble 1. Su m m a r y of Dia tom ic Su lfu r -Tr a p p in g
Exp er im en ts of 1,3-Dien e 42 w ith Dith io Ad d u cts 13 a n d
14
% yield 46b
% yieldb
from dithio
of adducts
entry
no.
temp time
1
identities were confirmed by H and 13C NMR as well as
Ra
solvent
(°C)
(h)
13
14
51
52
by mass spectrometry.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1:3 EtOAc
1:1 EtOAc
3:1 EtOAcc
3:1 EtOAcd
5:1 EtOAc
3:1 CH2Cl2
3:1 CHCl3
1:1 CHCl3
3:1 CHCl3
1:1 C6H5Cl
3:1 C6H5Clc
3:1 C6H5Cld
3:1 C6H5Cl
5:1 C6H5Cl
77
77
77
77
77
36
36
61
61
132
132
132
132
132
12
12
10
10
10
15
15
15
15
2
12
18
50
47
49
7
10
10
11
16
30
29
30
32
27
35
58
54
57
10
15
20
26
31
48
47
49
50
55
54
24
27
28
61
59
57
56
55
40
39
37
36
41
34
16
19
15
62
58
51
42
36
20
18
20
18
Byproducts, the acyclic tetrasulfide adducts 51-54,
chlorotriphenylmethane, and starting material along
with triphenylmethanethiol and elemental sulfur were
isolated in low yields. In addition, the corresponding
olefin was also detected by 1H NMR. The identity of
sulfide adducts 51-54 was confirmed by 1H and 13C NMR
as well as by elemenal analysis.
2
2
10
2
a
Refers to the molar ratio of disulfides 13 and 14 to 1,3-diene
42. isolated yields after flash chromatography. c 50 mL of the
solvent was used. 15 mL of the solvent was used.
b
d
rotriphenylmethane (19%), and elemental sulfur (17%).
1
Bicyclo[2.2.1]heptene (5) was detected by H NMR (ca.
8%).
In each case, there are two possible ways olefin could
form. Scheme 2, path a, shows the possible formation of
dithietane intermediate 4. Scheme 2, path b, displays a
concerted fragmentation producing diatomic sulfur and
olefin directly from intermediate 55. At present, it is not
clear which mechanism is followed.
Recently, we reported8 that stable 1,2-addition prod-
ucts 7 and 8 are formed when the reaction of triphenyl-
methanesulfenyl chloride 1 (or its thio (2) and dithio (3)
homologue) were treated with bicyclo[2.2.1]heptene (5)
and bicyclo[2.2.2]octene (6). While diatomic sulfur trans-
fers took place from them to a diene acceptor 42, the yield
of the final products was quite low. We tried to synthe-
size a new series of 1,2-addition products such as 13-17
in order to obtain better yields of 49 and 46. Olefins such
as cyclohexene (11) and cyclopentene (10) were used for
this purpose.
In contrast, we discovered that the addition products
(13 and 14 from 2; 16 and 17 from 3) are effective in
transferring two sulfur units to a diene trap when each
of the di- and trithio adducts 13, 14, 16, or 17 was heated
in the presence of diene 42. The decomposition was
further investigated by varying the reaction conditions
in an effort to maximize the yield of the trapped di-49
and tetracyclic adducts 46. A variety of solvents, tem-
peratures, times, and concentrations were employed to
optimize the yields of the trapped adducts. A summary
of the results is shown in Table 1 (disulfides 13 and 14).
Acyclic tetrasulfide adducts 51 and 52 were formed by
an intermolecular pathway as one of the minor products
(Tables 1). The same results were obtained in the case
of trisulfides 16 and 17 as shown in Table 5 of the
When 3 equiv of 7 were heated in ethyl acetate with 1
equiv of a standard diatomic sulfur trap, both cyclic
disulfide adduct 49 and cyclic tetrasulfide adduct 46 were
1
detected by H NMR.
Eventually, tetrasulfide 46 was isolated in 24% yield.
It is possible that intermediate 4 either transfers its two
sulfur atoms to the diene trap to form 49 or gives up S2,
which is then trapped (Scheme 3). As has been noted
by ourselves13d,e,16 and in other labs,17 a likely second trap
of a two-sulfur unit takes place, forming tetrasulfide 46.
The major product of the reaction is formed by an
intermolecular pathway when 7 is heated in ethyl
acetate, eventually giving the corresponding tetrasulfide
53 in 59% yield.
A possible pathway to explain this result is suggested
in Scheme 3. In addition, starting material (16%) was
isolated along with triphenylmethanethiol (27%), chlo-
(16) Chew, W.; Harpp, D. N. Sulfur Lett. 1993, 15, 247.
(17) (a) Gilchrist, T. L.; Wood, J . R. J . Chem. Soc., Chem. Commun.
1992, 1460. (b) Nicolaou, K. C.; DeFrees, S. A.; Hwang, C.-K.;
Stylianides, N. A.; Carroll, P. J .; Snyder, J . P. J . Am. Chem. Soc. 1990,
112, 3029.

8658 J . Org. Chem., Vol. 63, No. 24, 1998
Abu-Yousef and Harpp
Sch em e 4
Sch em e 5
Sch em e 6
Supporting Information. Other minor products such as
triphenylmethanethiol (ca. 29%) were also isolated along
with chlorotriphenylmethane (ca.17%), starting material
(ca. 9%), and elemental sulfur (ca. 24%). In addition,
cyclopentene (10) and cyclohexene (11) were detected by
1H NMR (ca. 7%). It is noteworthy to mention that an
independent experiment showed that cyclohexene and
elemental sulfur were produced upon the thermal de-
composition of cyclohexenesulfide with ethyl acetate (T
) 77 °C), with chlorobenzene (T ) 132 °C), and with
chloroform (T ) 61 °C).
Also, it should be mentioned that an independent
experiment showed that only about 40% of the theoretical
amount of chlorotriphenylmethane emerges from silica
gel chromatography; the trityl group is likely retained
by reaction with the siloxy functions in the silica gel. By
elution with methanol the trityl group was obtained (ca.
54%) in the form of triphenylmethanecarbinol (total
recovery ca. 94%).
In these experiments, low yields of triphenylmethane-
thiol and elemental sulfur were obtained. To explain
this, an independent experiment was carried out in which
a solution with known amounts of triphenylmethanethiol
and elemental sulfur was passed through the used
column under the same conditions. Only 50-55% of
these materials were isolated. It was necessary to use a
column with a particular eluent (10-20% chloroform in
hexane), since it was the only one that resulted in
efficient separation of our major product.
1
intermediate 4 or by a concerted expulsion of S2 from
intermediate 55 (Scheme 4). A second capture of a two-
sulfur unit apparently takes place, which results in cyclic
tetrasulfide adduct 46 as the major product. When an
excess amount of precursors 13, 14, 16, or 17 was
employed, there was a significant production of tetrasul-
fide adduct 46 from disulfide 49.
We found that cyclic tetrasulfide 46 can be converted
quantitatively to a disulfide adduct 49 by an in situ
treatment with triphenylphosphine (56) (eq 1).13e As a
result, this methodology serves to transfer a two-sulfur
unit to a diene in over 50% overall isolated yield.
(1)
The assignments of relevant 13C NMR chemical shifts
relative to tetramethylsilane of acyclic tetrasulfide ad-
ducts are reported in Table 7 of the Supporting Informa-
tion. In the case of dithio reagent 14, two decomposition
avenues are likely (Scheme 4).
The most probable mechanism for the formation of
cyclic tetrasulfide 46 from the thermal decomposition of
dithio reagent 14 in the presence of 42 is shown in
Scheme 4 above. A parallel path for the formation of 46
from 17 and 42 is shown in Scheme 5.
The formation of tetrasulfide 52 from 14 is rationalized
in Scheme 6; a parallel path for the formation of 52 from
trithio 17 is shown in Scheme 7.
Dithietane intermediate 415 (Scheme 4, path a) either
directly transfers its two sulfur atoms to the diene trap
to form 49 (Scheme 4, path a1) or undergoes a cyclo-
1
reversion to cyclohexene and S2, which is then trapped
(Scheme 4, path a2). Conversely, intermediate 55 could
1
fragment (Scheme 4, path b) directly to deliver S2 which
is then trapped (Scheme 4, path a2).
In sum, the stable sulfenyl chlorides 1-3 each add to
five different olefins to give stable adducts. These
adducts deliver a net two-sulfur transfer to various dienes
in overall isolated yields of up to 60%.
In addition, we found cyclohexene (11) in the crude
mixture; it is difficult to rationalize the presence of this
molecule except by the decomposition of dithietane

Sulfenyl Chloride Chemistry
Sch em e 7
J . Org. Chem., Vol. 63, No. 24, 1998 8659
Ta ble 2. P r ep a r a tion of Sta r tin g Ma ter ia ls
product
dithio trithio dithio trithio
% yieldb
time
(h)
alkene 1, 2, or 3 Ra
5
5
6
6
5
1
1
1
1
2
2
2
2
2
3
3
1:1
1:2
1:1
1:2
1:1
1:1
1:1
1:1
1:1
1:1
1:1
20
11
22
13
15
15
9
5
8
4
3
7
7
8
8
7
46
93
43
90
93
87
88
90
78
6
8
10
11
12
10
11
13
14
15
16
17
93
94
a
Refers to the molar ratio of alkene to sulfenyl chloride 1, 2, or
b
3. CH2Cl2 was used as a solvent in each case.
added dropwise to a stirred solution of cyclopentene (10) (0.426
g, 6.25 mmol) in 25 mL of dry methylene chloride under a
nitrogen atmosphere at room temperature. The mixture was
stirred for 7 h. Removal of the solvent under reduced pressure
and chromatography of the residue on silica gel with 15%
chloroform in hexane afforded an oily product, which solidified
under vacuum overnight. Recrystallization from n-pentane
gave 2.25 g (88%) of trans-2-chloro-1-(triphenylmethyldithio)-
Exp er im en ta l Section
Rea ction of Tr ip h en ylm eth a n esu lfen yl Ch lor id e (1)
w ith Bicyclo[2.2.1]h ep ten e (5). A typical procedure is
illustrated; the same general procedure follows for 6.
A
solution of triphenylmethanesulfenyl chloride18,19 (1) (1.97 g,
12.5 mmol) in 25 mL of dry methylene chloride was added
dropwise to a stirred solution of bicyclo[2.2.1]heptene (5) (1.177
g, 12.5 mmol) in 25 mL of dry CH2Cl2 under a nitrogen
atmosphere at room temperature. The mixture was stirred
for 20 h. Removal of the solvent under reduced pressure and
chromatography20 of the residue on silica gel with 10%
chloroform in hexane afforded an oily product, which solidified
upon treatment with 35-60 °C petroleum ether. Recrystal-
lization from n-pentane gave 47% yield of endo-2-chloro-exo-
1-(triphenylmethyldithio)bicyclo[2.2.1]heptane (7): mp 114-
1
cyclopentane (13): mp 99-101 °C; H NMR (CDCl3) δ 1.27-
2.40 (m, 7H), 4.30-4.40 (m 1H), and 7.21-7.70 (m, 15H) ppm;
13C NMR (CDCl3) δ 22.0, 28.9, 33.7, 55.3, 65.8, 71.4, 127.0,
127.9, 130.0, and 143.6. Anal. Calcd for C24H23Cl2S2: C, 70.18;
H, 5.60; S, 15.59. Found: C, 70.65; H, 5.60; S, 16.02.
In the case of 11, compound 14 was formed in 90% yield:
mp 103-104 °C; 1H NMR (CDCl3) δ 0.85-2.11 (m, 9H), 3.70-
3.85 (m, 1H), and 7.15-7.55 (m, 15H) ppm; 13C NMR (CDCl3)
δ 22.5, 22.8, 28.6, 32.8, 52.8, 62.3, 71.4, 127.0, 128.0, 130.2,
and 143.8 ppm. Anal. Calcd for C25H25ClS2: C, 70.69; H, 5.89;
S, 15.08. Found: C, 70.35; H, 6.08; S, 15.09.
1
115 °C; H NMR (CDCl3) δ 0.94-1.60 (m, 7H), 2.01-2.04 (m,
For 1,4-dioxene (12),21 compound 15 was isolated as an oily
product in a yield of 78%: 1H NMR (CDCl3) δ 3.38-3.50 (m,
2H), 3.58-3.61 (m, 1H), 4.11-4.20 (m, 2H), 5.31-5.36 (m, 1H),
and 7.45-7.18 (m, 15H) ppm; 13C NMR (CDCl3) δ 59.1, 59.7,
71.92, 88.2, 90.0, 127.7, 128.0, 130.0, and 143.2 ppm. Anal.
Calcd for C23H21ClO2S2: C, 64.40; H, 4.93; S, 14.95. Found:
C, 64.41; H, 4.94; S, 14.99.
Rea ction of Tr ip h en ylm eth a n ed ith iosu lfen yl Ch lo-
r id e (3) w ith Cyclop en ten e (10). By using dithiosulfenyl
chloride 3,20 in a similar way as for thiosulfenyl chloride 2, a
93% yield of 16 was obtained: mp 73-74 °C; 1H NMR (CDCl3)
δ 1.52-2.25 (m, 6H), 3.30-3.41 (m, 1H), 4.40-4.42 (m, 1H),
and 7.22-7.43 (m, 15H) ppm; 13C NMR (CDCl3) δ 22.0, 29.7,
34.3, 59.4, 65.1, 73.3, 127.2, 128.0, 130.3, and 143.2 ppm. Anal.
Calcd for C24H23ClS3: C, 65.11; H, 5.19; S, 21.71. Found: C,
65.32; H, 5.10; S, 21.99. The X-ray crystallographic structure
of trithio 16 has been reported.10
In the case of 11, compound 17 was formed in 94% yield:
mp 138-139 °C; 1H NMR (CDCl3) δ 1.30-1.71 (m, 6H), 2.11-
2.21 (m, 2H), 2.83-2.85 (m, 1H), 3.99-4.03 (m, 1H), and 7.17-
7.37 (m, 15H) ppm; 13C NMR (CDCl3) δ 23.51, 23.88, 30.33,
34.30, 56.49, 61.51, 73.42, 127.14, 127.91, 130.37, and 143.33
ppm. Anal. Calcd for C25H25ClS3: C, 65.74; H, 5.48; S, 21.04.
Found: C, 65.66; H, 5.72; S, 20.70. The X-ray crystallographic
structure of trithio 17 was reported for the first time.10
All of the experiments shown above are summarized in
Table 2.
1H), 2.28-2.30 (m, 1H), 3.62-3.64 (m, 1H), and 7.19-7.46 (m,
15H) ppm; 13C NMR (CDCl3) δ 21.8, 28.3, 35.13, 42.6, 44.8,
58.8, 66.4, 71.3, 126.9, 127.9, 130.2, and 143.7 ppm. Anal.
Calcd for C26H25ClS2: C, 71.50; H, 5.73; S, 14.67. Found: C,
71.81; H, 5.82; S, 14.88. The X-ray crystallographic structure
of dithio 7 was reported for the first time.8
In the case of 6, compound 8 was formed in 43% yield: mp
118-119 °C; 1H NMR (CDCl3) δ 1.92-1.21 (m, 11H), 3.60 (m,
1H), and 7.20-7.55 (m, 15H) ppm; 13C NMR (CDCl3) δ 18.6,
18.8, 25.0, 25.3, 28.7, 34.0, 55.9, 65.0, 71.2, 127.4, 128.3, 130.2,
and 143.8 ppm. Anal. Calcd for C27H27ClS2: C, 71.94; H, 5.99;
S, 14.21. Found: C, 71.85; H, 6.12; S, 14.32. The X-ray
crystallographic structure of dithio 8 was reported for the first
time.8
Rea ction of Tr ip h en ylm eth a n eth iosu lfen yl Ch lor id e
(2) w ith Bicyclo[2.2.1]h ep ten e (5). By using thiosulfenyl
chloride 2,20 in a similar preparation, a 93% yield of 7 was
obtained, which had identical spectral properties to the product
prepared using 1: mp 114-115 °C. 1H and 13C NMR data
were consistent with the structure of 7, which was prepared
via 1.
Rea ction of Tr ip h en ylm eth a n eth iosu lfen yl Ch lor id e
(2) w ith Bicyclo[2.2.2]octen e (6). By using thiosulfenyl
chloride 2,20 in a similar preparation, a 87% yield of 8 was
obtained, which had identical spectral properties to the product
prepared using 1: mp 118-119 °C. Spectral data were
consistent with the previous preparation of 8.
Rea ction of Tr ip h en ylm eth a n eth iosu lfen yl Ch lor id e
(2) w ith Cyclop en ten e (10). A typical procedure is il-
lustrated; the same general procedure follows for 11 and 12.
A solution of triphenylmethanethiosulfenyl chloride (2)20
(2.143 g, 6.25 mmol) in 20 mL of dry methylene chloride was
Th er m a l Ch em istr y of Dith io Ad d u ct 7. A representa-
tive procedure is illustrated for 7. The same was carried out
for 8, 13, 14, 16, and 17. The summary of these experiments
is shown in Table 3. A solution of endo-2-chloro-exo-1-
(triphenylmethyldithio)bicyclo[2.2.1]heptane (7) (0.6 g, 1.48
mmol) in 20 mL of dry ethyl acetate was refluxed for 40 h
under a nitrogen atmosphere. The reaction was followed by
thin-layer chromatography using 20% CHCl3 in hexane as
(18) Fieser, L. F.; Fieser, M. Reagents for Organic Synthesis; J ohn
Wiley & Sons: New York, 1967; Vol. 1, p 1121.
(19) Williams, C. R.; Britten, J . F.; Harpp, D. N. J . Org. Chem. 1994,
59, 806.
(20) Still, W. C.; Khan, M.; Mitra, A. J . Org. Chem. 1978, 43, 2923.
(21) Moss, R. D.; Paige, J . J . Chem. Eng. Data 1967, 12, 452.

8660 J . Org. Chem., Vol. 63, No. 24, 1998
Ta ble 3. Th er m a l Ch em istr y of Ad d u cts
Abu-Yousef and Harpp
% starting
reflux
(h)
% yield
tetrasulfide
adduct
% Ph3CSH
% Ph3CCl
% S8
% olefin
material
7
8
13
14
16
17
40
42
8
13
10
15
53 (68)
54 (60)
51 (65)
52 (69)
51 (67)
52 (65)
21
25
24
26
27
28
19
21
20
23
19
21
18
15
26
18
23
23
7
6
8
9
6
8
15
15
12
15
10
13
Ta ble 4. Tr a p p in g Exp er im en ts w ith 2,3-Dim eth yl-1,3-bu ta d ien e (42)
% yield
% yield
reflux
(h)
% starting
material
adduct
tetrasulfide
46
49
% Ph3CSH
% Ph3CCl
% S8
% olefin
7
8
36
36
8
10
13
24
15
53 (59)
54 (51)
51 (24)
52 (16)
24
19
50
58
45
60
63
6
5
8
10
7
9
25
23
26
28
24
30
29
23
21
21
18
20
20
17
14
18
18
17
12
25
24
5
7
9
8
6
6
7
10
14
12
10
14
8
13
14
15
16
17
51 (22)
52 (12)
8
9
eluent. After the solvent was evaporated under reduced
pressure, the products were separated by column chromatog-
raphy using the same eluent (20% CHCl3 in hexane), in which
the first fraction was isolated in a yield of 68% as an oily
product and identified as di[(2-chloro)-1-norbornyl] tetrasulfide
(53): 1H NMR (CDCl3) δ 1.22-2.09 (m, 6H), 2.51 (m, 2H), 3.15
(m, 1H), and 4.15 (m, 1H) ppm; 13C NMR (CDCl3) δ 21.87,
28.90, 35.84, 43.50, 44.75, 62.59 and 66.77 ppm. Anal. Calcd
for C14H20Cl2S4: C, 43.44; H, 5.17; S, 33.10. Found: C, 43.58;
H, 4.92; S, 33.04.
In the case of 8, compound 54 was formed in 60% yield,
respectively: 1H NMR (CDCl3) δ 1.20-2.15 (m, 10H), 3.58 (m,
1H), and 4.02 (m, 1H) ppm; 13C NMR (CDCl3) δ 19.27, 19.48,
25.36, 26.17, 30.61, 34.48, 61.55, and 64.96 ppm. Anal. Calcd
for C16H24Cl2S4: C, 46.29; H, 5.79; S, 30.86. Found: C, 46.10;
H, 5.65; S, 30.63.
di[(2-chloro)-1-norbornyl]tetrasulfide (53). Spectral data were
consistent with the previous isolation of 53. The second
fraction was isolated and identified as the cyclic tetrasulfide
adduct (46) (24%): 1H NMR (CDCl3) δ 3.63 (s, 4H) and 1.79
(s, 6H); 13C NMR (CDCl3) δ 18.12 (CH3), 42.76 (CH2) and
130.33 (CdC) ppm. MS (m/z, rel int., assignment) 210, 8%,
M+•; 146, 45%, M+• - S2; 82, 90%, M+• - S4; 67, 100%, M+•
-
CH3S4. Cyclic disulfide 49 was detected by 1H NMR in low
yield (ca. 6%).The same experiments were conducted for the
decomposition of dithio adducts 8 and 13-17 with 2,3-
dimethyl-1,3-butadiene (42). The full summary is found in
Table 4.
Th er m a l Ch em istr y of Cyclic Tetr a su lfid e 46 in th e
P r esen ce of Tr ip h en ylp h osp h in e (56). Triphenylphos-
phine (56) (0.142 g, 0.542 mmol) was added to a mixture of
cyclic tetrasulfide 46 (0.057 g, 0.271 mmol) in 40 mL of dry
diethyl ether. The solution was refluxed for 3 h under a
nitrogen atmosphere. The reaction was followed by thin-layer
chromatography using 15% CHCl3 in hexane as the eluent.
After the solvent was evaporated under reduced pressure, the
products were isolated by column chromatography using the
same eluent (15% CHCl3 in hexane), which afforded cyclic
disulfide 49 as an oily product in a yield of 98%: 1H NMR
(CDCl3) δ 1.74 (s, 6H) and 3.19 (s, 4H) ppm; 13C NMR (CDCl3)
δ 20.81, 34.15, and125.15 ppm. MS (m/z, rel int., assignment)
146, 75%, M+•; 82, 100%, M+• - S2; 67, 82%, M+• - CH3S2. In
addition, triphenylphosphine sulfide was isolated in a yield of
98%.
For 13 and 16,compound 51 was isolated in yields of 65%
and 67%, respectively: 1H NMR (CDCl3) δ 1.56-2.09 (m, 4H),
2.26-2.58 (m, 2H), 3.73-3.88 (m, 1H), and 4.51-4.69 (m, 1H)
ppm; 13C NMR (CDCl3) δ 22.59, 30.23, 34.79, 59.59, and 65.36
ppm. Anal. Calcd for C10H16Cl2S4: C, 35.85; H, 4.78; S, 38.24.
Found: C, 35.50; H, 4.49; S, 38.35.
In the case of 14 and 17, compound 52 was formed in 69%
and 65% yields, respectively: 1H NMR (CDCl3) δ 1.29-1.95
(m, 6H), 2.19-2.41 (m, 2H), 3.18-3.33 (m, 1H), and 4.19-4.25
(m, 1H) ppm; 13C NMR (CDCl3) δ 23.88, 24.29, 30.61, 35.07,
56.99, and 61.70 ppm. Anal. Calcd for C12H20Cl2S4: C, 39.70;
H, 5.51; S, 35.29. Found: C, 40.08; H, 5.33; S, 35.00.
Tr a p p in g of Dia tom ic Su lfu r fr om th e Decom p osition
of Dith io Ad d u ct 7 w ith 2,3-Dim eth yl-1,3-bu ta d ien e (42).
A sample procedure is as follows. 2,3-Dimethyl-1,3-butadiene
(42) (0.0125 g, 0.153 mmol) was added to a mixture of endo-
2-chloro-exo-1-(triphenylmethyldithio)bicyclo[2.2.1]heptane (7)
(0.20 g, 0.458 mmol) in 35 mL of dry ethyl acetate. The
solution was refluxed for 36 h under a nitrogen atmosphere.
The reaction was followed by thin-layer chromatography using
25% CHCl3 in hexane as the eluent. After the solvent was
evaporated under reduced pressure, the products were sepa-
rated by column chromatography using the same eluent (25%
CHCl3 in hexane), in which the first fraction was isolated in a
yield of 59% as an oily product and identified as the acyclic
Ack n ow led gm en t. We thank the Natural Sciences
and Engineering Research Council of Canada and F. C.
A. R. (Que´bec) for financial support of this work.
Su p p or tin g In for m a tion Ava ila ble: Copies of the 1H and
13C spectra of compounds 7, 8, 13-17, and 51-54 and tables
of bond length data for 7, 8, 16, and 17 and other relevant 13C
NMR data (27 pages). This material is contained in libraries
on microfiche, immediately follows this article in the microfilm
version of the journal, and can be ordered from the ACS; see
any current masthead page for ordering information.
J O9710792