Mono- and bisadducts from the addition of thianthrene cation radical salts to cycloalkenes and alkenes

Article abstract of DOI:10.1021/jo0104633

Thianthrene cation radical salts, Th^.+ X^-(X^- = a, ClO4^-; b, PF₆^-; c, SbF₆^-), add to cycloalkenes (C₅-C₈) in acetonitrile (MeCN) to form 1,2-bis(5-thianthreniumyl)cycloalkane salts and 1,2-(5,10-thianthreniumdiyl)cycloalkane salts, most of which have now been isolated and characterized. These are called bis- (3, 6, 9, 12) and monoadducts (4, 7, 10, 13). The proportional amount of the monoadduct obtained in the initial stage of the reaction varied with the cycloalkene in the order C₆ ? C₅ < C₇ ? C₈. Thus, the ratio bis:mono for C₅ and C₇ was, respectively, about 80/20 and 50/50. In contrast, only about 5% of the C₆ monoadduct (7a) and none of 7b, c was obtained, while for C₈ none of the bisadducts 12a-c was found. Bisadducts 3 and 9 lost thianthrene (Th) slowly in MeCN solution and changed into monoadducts 4 and 10. A comparable change from 6a into 7a was not observed. The monoadducts, themselves, lost a proton slowly in dry MeCN and opened into 1-(5-thianthreniumyl)cycloalkenes (5, 8, 11, 14). With 3 and 9, particularly, it was possible to follow with NMR spectroscopy the succession of changes, for example, 3 to 4 to 5. The opening of a monoadduct was made faster by adding a small amount of water to the solution. The bisadducts of 4-methylcyclohexene (15a) and 1,5- cyclooctadiene (17a) were isolated and characterized. Although a small amount of monodduct (16a) of 4-methylcyclohexene was found with NMR spectroscopy, it could not be isolated. Bis- and monoadducts were obtained also in additions of Th^.+ ClO₄^- to acyclic alkenes, in relative amounts that, again, varied with the alkene. From cis-2-butene the dominant product was the bisadduct (18), while the monoaduct (19) was characterized with NMR spectroscopy but could not be isolated. In contrast, trans-3-hexene gave mainly the monoadduct (21), while the bis adduct (20) could not be isolated. With 4-methyl-cis-2-pentene, both bis- (22) and monoadduct (23) were isolated, the former being dominant. The conversion of 18 into 19 was characterized with NMR spectroscopy. In all cycloalkene bisadducts, the configurational relationship of the two thianthrenium groups was trans, while in the monoadducts, the bonds to the single thianthrene dication were (necessarily) cis. In both bis- and monoadducts of acyclic alkenes, the configuration of the alkene was retained. The mechanisms of addition with retention of configuration, of conversion of a bis- into a monoadduct, and of opening of a monoadduct are discussed. Products were identified with a combination of NMR spectroscopy, X-ray crystallography, elemental analysis, and (for cycloalkene adducts) reaction with thiophenoxide ion.

Full text of DOI:10.1021/jo0104633

4
030
J . Org. Chem. 2002, 67, 4030-4039
Mon o- a n d Bisa d d u cts fr om th e Ad d ition of Th ia n th r en e Ca tion
Ra d ica l Sa lts to Cycloa lk en es a n d Alk en es
†
,†
‡
‡
Ding-Quan Qian, Henry J . Shine,* Ilse Y. Guzman-J imenez, J ohn H. Thurston, and
‡
Kenton H. Whitmire
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and
Department of Chemistry, Rice University, Houston, Texas 77005
henry.shine@ttu.edu
Received May 7, 2001
Thianthrene cation radical salts, Th•+ X (X ) a , ClO
-
-
-; b, PF -; c, SbF -), add to cycloalkenes
6 6
4
(C
5
-C ) in acetonitrile (MeCN) to form 1,2-bis(5-thianthreniumyl)cycloalkane salts and 1,2-(5,10-
8
thianthreniumdiyl)cycloalkane salts, most of which have now been isolated and characterized. These
are called bis- (3, 6, 9, 12) and monoadducts (4, 7, 10, 13). The proportional amount of the
monoadduct obtained in the initial stage of the reaction varied with the cycloalkene in the order
C
5
6
, C
0/50. In contrast, only about 5% of the C
for C none of the bisadducts 12a -c was found. Bisadducts 3 and 9 lost thianthrene (Th) slowly in
5
< C
7
, C
8
. Thus, the ratio bis:mono for C
5 7
and C was, respectively, about 80/20 and
6
monoadduct (7a ) and none of 7b,c was obtained, while
8
MeCN solution and changed into monoadducts 4 and 10. A comparable change from 6a into 7a
was not observed. The monoadducts, themselves, lost a proton slowly in dry MeCN and opened
into 1-(5-thianthreniumyl)cycloalkenes (5, 8, 11, 14). With 3 and 9, particularly, it was possible to
follow with NMR spectroscopy the succession of changes, for example, 3 to 4 to 5. The opening of
a monoadduct was made faster by adding a small amount of water to the solution. The bisadducts
of 4-methylcyclohexene (15a ) and 1,5-cyclooctadiene (17a ) were isolated and characterized. Although
a small amount of monodduct (16a ) of 4-methylcyclohexene was found with NMR spectroscopy, it
could not be isolated. Bis- and monoadducts were obtained also in additions of Th•+ ClO
-
to acyclic
4
alkenes, in relative amounts that, again, varied with the alkene. From cis-2-butene the dominant
product was the bisadduct (18), while the monoaduct (19) was characterized with NMR spectroscopy
but could not be isolated. In contrast, trans-3-hexene gave mainly the monoadduct (21), while the
bis adduct (20) could not be isolated. With 4-methyl-cis-2-pentene, both bis- (22) and monoadduct
(23) were isolated, the former being dominant. The conversion of 18 into 19 was characterized
with NMR spectroscopy. In all cycloalkene bisadducts, the configurational relationship of the two
thianthrenium groups was trans, while in the monoadducts, the bonds to the single thianthrene
dication were (necessarily) cis. In both bis- and monoadducts of acyclic alkenes, the configuration
of the alkene was retained. The mechanisms of addition with retention of configuration, of conversion
of a bis- into a monoadduct, and of opening of a monoadduct are discussed. Products were identified
with a combination of NMR spectroscopy, X-ray crystallography, elemental analysis, and (for
cycloalkene adducts) reaction with thiophenoxide ion.
1
It was reported recently from these laboratories that,
separate and isolate each pair of mono- and bisadducts
of the C -C cycloalkenes, except for the monoadducts
contrary to earlier understanding,2 thianthrene cation
radical could form not only bis- but also monoadducts in
its reactions with cycloalkenes. We showed that the
-4
5
8
of cyclooctene (13a -d ), which are formed without ac-
companiment of bisadducts, and a bisadduct (3c) of
cyclopentene. We were restricted to identifying the
remaining members of the pairs of adducts from the NMR
spectra of their mixtures. We return now to the adducts
of the cycloalkenes, having been able to separate and
1
aromatic portion of the H NMR spectrum of a monoad-
duct was akin to that of a thianthrene dication (1), while
in a bisadduct, each of the thianthrenium units, which
may or may not be equivalent, had the character of a
study all pairs of the adducts to the C
5
7
-C cycloalkenes.
Further, we have found that bis- and monoadducts can
also be formed with acyclic alkenes, and we report here
those of cis-2-butene (18 and 19), trans-3-hexene (20 and
2
1), and 4-methyl-cis-2-pentene (22 and 23), Scheme 2,
their structures, and a proposed mechanism of their
(
1) Lee, W. K.; Liu, B.; Park, C. W.; Shine, H. J .; Guzman-J imenez,
I. Y.; Whitmire, K. H. J . Org. Chem. 1999, 64, 9206-9210.
2) Shine, H. J .; Bandlish, B. K.; Mani, S. R.; Padilla, A. G. J . Org.
thianthrenium ion (2). At that time, we were not able to
(
Chem. 1979, 44, 915-917.
*
To whom correspondence should be addressed. Fax: 806-742-1289.
Texas Tech University.
Rice University.
(3) Iwai, K.; Shine, H. J . J . Org. Chem. 1981, 46, 271-276.
(4) Houmam, A.; Shukla, D.; Kraatz, H.-B.; Wayner, D. D. M. J .
Org. Chem. 1999, 64, 3342-3345.
†
‡
1
0.1021/jo0104633 CCC: $22.00 © 2002 American Chemical Society
Published on Web 05/17/2002

Addition of Thianthrene Cation Radical Salts to Cycloalkenes
J . Org. Chem., Vol. 67, No. 12, 2002 4031
Sch em e 1
Sch em e 4
1
4) the bis- and monoadducts of the C
and the 1-(5-thianthreniumyl)cycloalkenes, the adducts
15, 16) of 4-methylcyclohexene and (17) of 1,5-cyclocta-
5
-C
8
cycloalkenes,
(
diene. Not all of the cycloalkenes gave a complete set of
adducts. From cyclohexene, the only monoadduct that
could be obtained was 7a , and in only about 5% conver-
sion as compared with 95% of the bisadduct 6a . Monoad-
ducts 7b,c were not found. Although the bisadduct (12)
of cyclooctene is listed, none could be found in any of the
reactions of cyclooctene with thianthrenium salts. Be-
tween these extremes, the percentage ratio 3:4 of the
cyclopentene adducts, obtained in preparative experi-
ments, was about 80/20 for all salts (a -c), while for 9:10
from cycloheptene it was about 50/50. Having found now
that in MeCN solution the bis adducts 3 and 9 slowly
lost Th and were converted into monoadducts 4 and 10,
we felt that, possibly, a cyclooctene bisadduct (12) was
being missed because of its rapid conversion into 13.
Sch em e 2
•
+
Therefore, reaction of Th with cyclooctene was moni-
tored with NMR spectroscopy as soon as it was instru-
mentally possible (15 min), but no sign of a bisadduct
could be found. Further, reaction was carried out on a
larger scale than was customary in order to search for a
small amount of bisadduct in the product, but again, none
could be found. In addition, in seeking information on
the timing of formation of bis- and monoadducts, we
examined the effect of time on the reaction of cyclohep-
•
+
-
tene with Th ClO
4
and found the ratio bis:mono to be
7
0/30 after 5 and 70 min.
A similar circumstance was found with the acyclic
alkenes, whose adducts (18-23) are listed in Scheme 2.
•
+
-
The major product from the addition of Th ClO
4
to cis-
2
-butene was the bisadduct (18). A small amount of
monoadduct (19) was found in the NMR spectrum of the
crude product, the percentage ratio 18:19 being about 95/
Sch em e 3
5
. In contrast, the major product from trans-3-hexene was
the monoadduct (21) with a small amount of bisadduct
20), the NMR ratio 20:21 being about 5/95. Between
these two extremes was the reaction with 4-methyl-cis-
-pentene, in which the bis:mono ratio was 75/25. Again,
(
2
a search was made, this time with 20 and 21, by
monitoring the formation of adducts, to find if a bis- was
being converted rapidly into the monoadduct. The NMR
•
+
-
spectrum of the reaction mixture of Th ClO
-hexene was recorded as soon as experimentally feasible
35 min) and while the presence of a small amount of
4
with trans-
3
(
formation. We report, also, as shown in Scheme 3, that
in acetonitrile (MeCN) solution, bisadducts 3, 9, 18, 20
slowly lost thianthrene (Th) and became converted into
monoadducts 4, 10, 19, 21. Even more slowly, the
monoadducts 4, 7, 10, 13 opened with the loss of a proton
into the corresponding 1-(5-thianthreniumyl)cycloalkenes
•
+
Th was inferred by its light pink color and by the
broadening it caused in the NMR peaks of Th in the
mixture. The relative amounts of mono- and bisadduct
were measured from their methyl-group signals, and the
ratio mono:bis remained the same (90/10) over a period
of 3 h.
5
, 8, 11, 14 (Scheme 4). Last, we report the reactions of
some of the cyclic adducts with thiophenoxide ion, these
reactions having a bearing on the structure of the adducts
Thus, formation of bis- and monoadducts from both
cyclic and acyclic alkenes appears to occur initially not
successively but in parallel.
Resu lts a n d Discu ssion
In all cycloalkene bisadducts the two thianthrenium
groups are trans to each other. This relationship was
Ad d u cts a n d Th eir Str u ctu r es. The adducts of
cycloalkenes are listed in Scheme 1. They comprise (3-
3
deduced for 6a from its chemical reactions some time ago

4
032 J . Org. Chem., Vol. 67, No. 12, 2002
Qian et al.
and was demonstrated with X-ray crystallography later
by Wayner. We have now characterized the bisadducts
Sch em e 5
Sch em e 6
4
9
a , 15a , 17a , 18, and 22 with X-ray crystallography and
the trans-relationship of their thianthrenium groups is
evident in each of their Ortep diagrams (Figures F1, F3-
5
, and F7). The bisadduct 22 was reported earlier by
4
Wayner, but a commitment on structure was not made.
Growth of single crystals of the other bisadducts reported
here, suitable for X-ray crystallography, was unsuccess-
ful.
Apart from X-ray crystallography, the NMR spectrum
of each bisadduct was consistent with its structure. In
+
6
a , the two Th groups are equivalent, and the aromatic
1
H NMR spectrum consequently consists of two dd (two
sets of 4,6- and 1,9-protons) and two td (the two sets of
+
2
,8- and 3,7-protons).1,4 Equivalence of the two Th
1
13
groups was also found in 18 with H and C NMR data.
In all the other bisadducts the two Th groups were not
+
magnetically equivalent. Thus, the spectrum of 9a had
four dd attributable to the 4,6-, 4’,6’-, 1,9-, and 1’,9’-
protons, three td attributable (arbitrarily) to the 2,8-,
2
3
’,8’- and 3,7-protons, and one ddd attributable to the
’,7’-protons and indicating a lack of equivalence even
+
within one Th group.
Most striking among structures of bisadducts are
those of 18 and 22. In each of these, the configuration of
the alkene has been retained in the alkane. These
bisadducts are threo-stereoisomers. This can be seen in
the Ortep diagrams of 18 and 22 (Figures F5 and F7), in
which the relationships of the staggered threo configu-
ration are clearly seen. Insofar as 22 is concerned, its
structure can be compared with those of threo-2,3-
dibromo- and threo-2,3-dichloro-4-methylpentane, re-
5
property attributable to an erythro configuration and to
7
cis-related protons as in comparable rigid structures,
particularly such as those in dibenzo[2.2.2]cyclooctadienes.
8
Monoadduct 19 could not be isolated. It was identifiable
1
13
only from its aromatic H (four sets of dd) and C (six
peaks) NMR spectra, which were clearly discernible in
the NMR spectra of its mixture with bisadduct 18. We
assume, in analogy with adducts 21 and 23, and guided
by the retention of cis-2-butene’s configuration in bisad-
duct 18 (Figure F5), that monoadduct 19 has an erythro
structure, too, arising from retention of alkene configu-
ration.
5
ported by Kingsbury and Best. In the NMR spectrum of
2
2 3
2 the small coupling (1.75 Hz) between the C and C
methine protons is diagnostic of a threo- rather than an
5
erythro-isomer. Thus, the bisadducts 18 and 22 have
been formed in a trans-addition, without allowing for or
entailing rotation about the erstwhile double bond.
Addition was stereospecific. Trans-addition of the two
The pattern has emerged that both bis- and monoad-
ducts are formed stereospecifically. Stereospecific trans-
addition in bisadducts is readily interpretable if a
thiirane-type radical ion intermediate (24) is formed and
is opened by the attack of a second cation radical (Scheme
+
Th groups to the cycloalkenes is assumed to follow the
same path.
Each of the newly isolated monoadducts from the
5
). But, such an intermediate is not suited to stereospe-
1
cycloalkenes (4b, 7a , 10a ) had the aromatic H NMR
cific monoadduct formation, since, for that, front-side
intramolecular attack on the thiirane ring by the remote
sulfur atom would be needed. In a monoadduct, the two
bonds from alkane carbon to thianthrenium sulfur are
cis-related. Achieving that relationship stereospecifically
from a thiirane-type intermediate would not be reason-
able. Instead, we propose that monoadducts are formed
in a concerted addition analogous to the [3 + 2] Diels-
Alder cation-radical cycloadditions that have been char-
acterized extensively by Bauld. In monoadduct forma-
tion, however, cycloaddition is stoichiometric, not catalytic,
and the intermediate distonic, sulfuranyl cation radical
adduct (25) serves not to propogate a chain but to reduce
spectrum of four sets of dd, as reported earlier for 13.1
Single-crystal X-ray crystallography was achievable with
only one of the new cyclic monoadducts, 4b (Figure F2).
Among the monoadducts of the acyclic alkenes, only one
(
21), from trans-3-hexene, could be characterized with
X-ray crystallography. The Ortep diagram (Figure F6)
shows that the adduct has a threo structure in which the
configuration of the trans-3-hexene is retained. Despite
1
its apparent symmetry, 21 had a complex H NMR
9
spectrum, indicative of long-range,virtual coupling among
9
6
alkyl H atoms. The aromatic proton signals were not
grouped in four separate dd, but were overlapped in two
multiplets, each of 4H. Nevertheless, the 13C spectrum
of six aromatic and three alkyl signals was as predicted
for the structure. That the alkene configuration was
•+
the second Th (Scheme 6). In this proposal, the central
ring of the cation radical, with high spin density on the
1
retained in the monoadduct 23 is deducible from its H
(
7) Marchand, A, P. Stereochemical Applications of NMR. Studies
NMR spectrum. Coupling between the methine protons
on atoms C and C was relatively large (7-8 Hz), a
2 3
in Rigid and Bicyclic Systems. Methods of Stereochemical Analysis;
Verlag Chemie Intl.: Deerfield Beach, FL, 1982; Vol. 2, pp 143-144.
(
8) Cristol, S. J .; Russell, T. W.; Mohrig, J . R.; Plorde, D. E. J . Org.
Chem. 1966, 31, 581-584.
(
(
5) Kingsbury, C. A.; Best, D. C.; J . Org. Chem. 1967, 32, 6-10.
6) Silverstein, R. M.; Webster, F. X. Spectrometric Identification of
(9) (a) Bauld, N. L. In Advances in Electron-Transfer Chemistry;
1992; Vol. 2, pp 1-66. (b) Bauld, N. L. Tetrahedron 1989, 45, 5307-
5363.
Organic Compounds, 6th ed.; Wiley: New York, 1998; pp 179-183.

Addition of Thianthrene Cation Radical Salts to Cycloalkenes
J . Org. Chem., Vol. 67, No. 12, 2002 4033
Sch em e 7
Sch em e 9
Sch em e 8
compromised. The reactions of all of these adducts with
thiophenoxide ion are interpretable on the basis of the
proposed structures of the adducts.
Rin g-Open in g in Mon oaddu cts. When kept in MeCN
solution, each of the monoadducts 4, 7, 10, and 13 lost a
proton and opened into a 1-(5-thianthreniumyl) cycloal-
kene (5, 8, 11, and 14). These changes were slower (4,
1
0, 13) than those of the corresponding bis- into monoad-
ducts, but we have not made quantitative comparisons
among the four monoadducts. The conversion of 10b into
5
,10-sulfur atoms,10 serves as the diene-like cation radical
1
1b, for example, was followed with NMR spectroscopy,
in the cycloaddition.
and 50 days elapsed before the spectrum of 10b was no
longer visible. In this and other monoadduct conversions,
a small amount of Th was formed, indicative of an
elimination reaction with, in the case of 10b, formation
of 1,3-cycloheptadiene, but that reaction was not ex-
plored. We found that deprotonation of a monoadduct was
faster in wet than in dry MeCN. Some of the reactions
The intermediate 25 could also serve as the source of
stereospecific bisadduct formation. In that case, the
competition between bis- and monoaddition amounts to
bonding with or oxidizing 25 by the second Th• (Scheme
+
6
). At this stage we do not know why bonding would be
favored in one reaction (e.g., in cyclohexene’s case) and
oxidation in another (e.g., in cyclooctene’s case). Nor do
we know if trans-3-hexene favors monoaddition and the
cis-alkenes favor bisaddition because of their geometric
differences. It seems unlikely that differences in the
oxidation potentials of the relevant distonic sulfuranyl
cation radicals would be marked enough to control the
pathways, suggesting that structural or conformational
factors are in control. These perplexing questions await
elucidation.
were followed with NMR spectroscopy in CD
ing D O. For example, whereas none of 11c but a small
amount of Th was formed from 10c in CD CN in 3 days,
addition of two drops of D O led to 35% of 11c in the
same period. Addition of a further 0.1 mL of D O caused
complete loss of 10c in 11 days. Analogously, 7a in dry
CD CN was converted completely into 8a and Th in the
ratio 35/65 in 13 days. A similar solution containing 0.1
mL of D O led completely in 18 h to 8a and Th in the
3
CN contain-
2
3
2
2
3
2
Isolation of all of the cycloalkene adducts (except 12)
allowed us to use an additional method of characterizing
an adduct, namely, from the stoichiometry and products
of its reaction with thiophenoxide ion, a technique we
ratio 80/20 and allowed for the isolation and X-ray
characterization of 8a (Figure F8). In this reaction a
small amount of 1,3-cyclohexadiene was found by GC but
was not measured. These and similar experiences with
1
reported earlier. This reaction was used with 3a , 6a , 9a ,
4
a and 13a indicate that water served as a base (B in
1
0a , and 17a . Reactions of 6a , 9a , and 17a gave cyclo-
Scheme 4). A study of the comparative ease of deproto-
nation of the four monoadducts was not made nor was
hexene, cycloheptene, and 1,5-cyclooctadiene, respec-
tively, along with Th and DPDS, according to the
stoichiometry of the trans-elimination reaction shown in
Scheme 7, in which thianthrene structures are shown in
abbreviated form. Apart from this, the major route of
reaction, a small amount of 1-(phenylthio)cycloalkene was
formed from 6a and 9a , as is proposed in Scheme 8.
Reaction of 10a with thiophenoxide ion gave cyclohep-
tene, 1-(phenylthio)cycloheptene, Th, and DPDS, analo-
gously. A striking exception to the dominant pathway of
Scheme 7 was in the reaction of 3a , Scheme 9. We
reported that reaction earlier, but were not then able to
distinguish between 1- and 3-(phenylthio)cyclopentene as
one of the products. That has now been settled. Thus,
2
1 studied in this way.
Con ver sion of Bis- in to Mon oa d d u cts. When left
in MeCN solution, all bisadducts slowly changed into the
corresponding monoadducts, except for 6 whose conver-
sion into 7 was too slow to follow. The conversion was
studied mostly of 9 into 10, because both 9 and 10 were
readily isolable and characterizable, the conversion could
be followed daily, and the further conversion of 10 into
1
1 was too slow to interfere. In contrast, for example,
although the conversion of the cyclopentene adducts, 3
into 4, could be followed with NMR spectroscopy, the
spectra became complicated eventually by the concomi-
tant conversion of 4 into 5.
+
the dominant reaction (94%) of 3a is substitution of Th
Conversion of the bisadduct (18) of cis-2-butene into
-
-
by PhS . The thiophilicity of PhS , which led to elimina-
tion with the other adducts, is suppressed or inhibited
in 3a , suggesting that access by PhS to the sulfonium
1
9 was very slow but was followed with NMR spectros-
copy.
The conversion of 9 into 10 occurred cleanly in
CD CN solutions that were shielded from light. When
-
+
sulfur atoms of the Th groups in 3a is sterically
3
such solutions were exposed to daylight or fluorescent
light, the thianthrene cation radical was formed in low
(
10) Shine, H. J . In The Chemistry of the Sulfonium Group; Stirling,
C. J . M.; Patai, S., Eds.; Wiley: New York, 1981; pp 523-569.

4
034 J . Org. Chem., Vol. 67, No. 12, 2002
Qian et al.
concentration, as was shown with absorption and esr
spectroscopy. Nevertheless, conversion could be followed
with NMR spectroscopy. Our discussion, then, is of
shielded solutions first and of unshielded solutions next.
Both 9a and 9c were used in NMR tubes shielded with
foil except when in the NMR probe. The relative amounts
of 9 and 10 were measured from the integrations of their
aromatic proton signals and also their methine proton
signals daily over a period of 6 to10 days. At all times,
the integration of the most downfield 4H dd of 10 was
equal to those of the two sets of 4H dd of Th, showing
that conversion was stoichiometrically correct. Rates of
conversion were calculated from the initial concentration
of 9 and the concentrations obtained from the ratios 9:10
at timed intervals. Reasonably good first-order rate plots
were obtained. The rate of conversion of 9c (k ) 9.6 (
Sch em e 10
was involved that allowed for rotation of the alkyl chain.
However, only one monoadduct (19) was found in the
changing NMR spectrum. The conversion of 18 into 19
-
3
-1
was slower (k ) 2.6 ( 0.14 × 10
h ) than that of 9
into 10. When exposed to light, a solution of 18 behaved
analogously to one of 9, but the rate of conversion into
-3
-1
0
.5 × 10
h ) was not affected by the presence of added
-
3
-1
-
3
-1
19 (k ) 2.6 ( 0.14 × 10
h ) was unaffected by
Th (k ) 9.3 ( 0.4 × 10
h
). That is, conversion was
illumination. Small peaks of a new multiplet at 5.45 ppm
and doublet at 1.57 ppm had appeared, too. These
changes were not followed further.
irreversible. Irreversibility was confirmed with the un-
changing NMR spectrum of a solution of 10a containing
added Th; no sign of 9a was found over a period of 6 d,
when the experiment was stopped. The lack of effect of
Th on the formation of 9 and 10 was confirmed also by
Our overall view of these conversions is that the effect
of light encountered here is coincidental to the conversion
and does not affect it substantially. It is noteworthy,
however, that the bis- and monoadducts are colorless and
the light-induced formation of Th occurred in Pyrex
vessels. 9a , for example, has absorption bands at 237 and
•
+
-
measuring the ratio 9a :10a in the addition of Th ClO
4
to cycloheptene in the absence and presence of added Th.
That is, the ratio 9a :10a was measured in their mixture
that was precipitated as soon as addition was complete
and was found to be unaffected by having added Th to
the solution. The results of the several approaches show
that in shielded solutions 9 is converted cleanly and
irreversibly into 10. Solutions remained colorless through-
out the conversion and, in this way, failed to show the
•
+
3
10 nm, with extinction coefficients 41000 and 7400;
there is no measurable absorption above 360 nm. Further
study is planned. The shielded conversion itself appears
to be intramolecular and the result of displacement of
+
one Th group by the distant S atom of the other (Scheme
•
+
10). In 9 and other cycloalkane adducts, rotation about
the pertinent cycloalkane C-C bond during conversion
is not possible. In the acyclic adduct (18), where in
principle rotation and a change in configuration could
occur, it does not, attesting to the concerted nature of
the displacement.
presence of Th .
The effect of light on solutions of 9 was investigated
with a solution of 9c comparable to those that had been
shielded from light. The solution was kept under labora-
tory daylight and fluorescent light and soon became light
pink in color. The color intensified during exposure and
diminished during darkness. NMR measurements of the
amounts of 9c and 10c were made in the usual way, but
the signals from Th were broad and shallow. The rate of
Exp er im en ta l Section
Solvent acetonitrile (MeCN) was dried by distillation from
P O followed by distillation from CaH . Alkenes, cycloalkenes,
and cycloalkanones were from commercial sources. Two GC
columns were used: Column A, 10% OV-101 on 80-100 mesh
Chrom-WHP, 4 ft x 1/8 in stainless steel (ss), and column B,
-
3
conversion was a little faster (k ) 11.5 ( 0.18 × 10
) than in the shielded solution. Gradually, small NMR
signals from ThO were detected overlapping the upfield
2
5
2
-1
h
•
+
aromatic signals from 9c. Thus, Th was formed in the
presence of light and was hydrolyzed to ThO (and Th)
by the water remaining in the solvent. The formation of
2
0% BEEA on 60-80 mesh Chrom-PAW, 8 ft x 1/8 in ss.
Thianthrene cation radical salts (Th ClO
•
+
-
•+
-
6
4
, Th PF
, and
•+
-
1
Th SbF
explosiveness of Th ClO
6
) were prepared as described earlier. The potential
•
+
Th under laboratory illumination was confirmed in
separate experiments with absorption and esr spectros-
•+
-
11
4
should be noted. NMR spectra list
δ (J ) in ppm and Hz. Elemental analyses were by Desert
Analytics, Tucson, AZ. Mass spectra were provided by Dr.
Terry Marriott, Rice University.
P r ep a r a tion a n d Sep a r a tion of Bis- a n d Mon oa d d u cts.
A detailed example is given with 1,2-bis(5-th ia n th r en iu m -
yl)cycloh ep ta n e d ip er ch lor a te (9a ) and 1,2-(5,10-th ia n -
th r en iu m d iyl)cycloh ep ta n e d ip er ch lor a te (10a ). A solu-
tion of 1.78 g (18.5 mmol) of cycloheptene in 2 mL of MeCN
was added dropwise to a stirred suspension of 1.00 g (3.17
•
+
copy. Absorbances of the bands characteristic of Th at
39, 915, and 1032 nm showed that the concentrations
5
•
+
of Th amounted to 1-3% of the initial amount of 9c.
•
+
-
6
The esr spectrum was identical with that of Th PF .
•
+
Th was not found in a solution of 10a or of Th that was
exposed to light.
The effect of Th on the conversion was also investi-
gated with the addition of Th ClO
•
+
•
+
-
•+
-
4
4
(0.0085 mmol) to a
mmol) of Th ClO
in 8 mL of MeCN at room temperature.
solution of 9a (0.0106 mmol). The rate of conversion (8.2
The purple color of the solution faded to pink, and a white
precipitate formed after the addition of the cycloalkene was
finished. The mixture was stirred overnight (20 h), after which
the solution was slightly yellow and the precipitate slightly
pink. Dried ether was added and produced more precipitate,
which was filtered, washed with ether, and dried under vac-
uum to give 870 mg of product. The aromatic portion of the
-
3
-1
(
×
0.67 x 10
h ), was unchanged from that (8.0 ( 0.3
-
3
-1
•+
-
10
4
h ) in the absence of added Th ClO . The
spectrum of Th that was formed, however, was again
•
+
broadened by exchange with Th , and the gradual
formation of ThO was pronounced.
1
Bisadduct 18 also lost Th and changed into 19 cleanly
in the dark. We used 18 because in principle it could give
two monoadducts if a dissociative pathway of conversion
H NMR spectrum showed that the product was a mixture of
(11) Shine, H. J .; Yeuh, W. J . Org. Chem. 1994, 59, 3553-3359.

Addition of Thianthrene Cation Radical Salts to Cycloalkenes
bis- and monoadducts of Th•+ClO -
J . Org. Chem., Vol. 67, No. 12, 2002 4035
the ratio 90/10. This represents 79% recovery of Th•+ClO -,
4
to cycloheptene and the
4
ratio of the adducts, from the integrated low-field and high-
field signals, was, for 9a :10a , 60/40. These data showed that
with 71% as 3a and 8% as 4a . Separation and recrystallization
gave 3a , mp 165-167 °C dec, and 4a , mp 177-178 °C dec. H
3
NMR, CD CN, 500 MHz (3a ): 8.110 (8.0, 0.5, 0.5), dd, 4H;
1
1
the total yield of adducts was 86%, namely 50% of 9a and 36%
of 10a . The product was dissolved in 20 mL of MeCN. Ether
was added dropwise until the solution became turbid. After
several minutes, a mixture of needlelike and denser, powdery
crystals deposited. Addition of ether to the clear supernatant
solution, causing further precipitation, was continued until
precipitation stopped. The mixture was swirled, allowing for
the decantation and filtration of the lighter, needlelike crystals,
which were washed with ether and dried to give 350 mg of
solid, A. The remaining solids, a mixture of powdery and
needlelike crystals was filtered and treated similarly to give
7.919 (8.25, 1.5, 1.0), dd, 2H; 7.863 (7.25, 8.0, 1.0, 1.5, 1.5), td,
2H; 7.842 (7.5, 8.0, 1.5, 1.5, 1.5), td, 2H; 7.777 (7.75, 7.75, 1.0,
1.5, 1.0), td, 2H; 7.725 (7.75, 7.75, 1.5, 1.0, 1.5), td, 2H; 7.576
(8.0, 1.0, 1.0), dd, 2H; 4.879 (7.5, 2.5, 2.5), dd, 2H; 2.357 (7.7
ave), sext, 2H; 2.219 (7.13 ave), quint, 2H; 1.91, m (overlapping
solvent). (4a ): 8.622 (6.0, 3.5, 3.5), dd, 2H; 8.527 (5.5, 3.5, 3.5),
dd, 2H; 8.200 (6.0, 3.5, 3.0), dd, 2H; 8.104 (6.0, 3.0, 3.5), dd,
2H; 4.873, m, 2H; 2.52-2.46, m, 2H; 1.78-1.69, m, 1H; 1.57-
1.49, m, 2H; 1.43-1.36, m, 1H. Anal. Calcd for C17
16 2
H S -
Cl .CH CN (4a ): C, 43.5; H, 3.65; S, 12.2; Cl, 13.5. Found:
2
O
8
3
3
90 mg of solid, B. The filtrate was concentrated to give a
C, 43.0; H, 3.46; S, 12.4; Cl, 13.9. Single crystals of 4a failed
precipitate, which was dissolved in a small amount of MeCN
to which ether was added, giving 60 mg of solid, C. Again, the
filtrate was concentrated and gave 80 mg of thianthrene (Th).
Each of the solids, A, B, and C was again subjected to fractional
precipitation, and each time the precipitates of needlelike and
powdery crystals were combined, separately. Finally, 301 mg
of needles (solid D) and 212 mg of powdery solid (E) were
to diffract well.
Reaction of cyclopentene (8.0 mL, 91 mmol) with Th•+PF
-
6
(700 mg, 1.94 mmol) gave 650 mg of a mixture of 3b and 4b
in the ratio 85/15, representing 82% recovery of Th• PF
+
-
with
6
75% as 3b and 7% as 4b. Workup gave 3b, mp 168.2-169 °C
dec, and 4b, mp 176-177.5 °C dec, each having an acceptable
1
H NMR spectrum. A single crystal of 4b diffracted success-
1
obtained. H NMR spectroscopy showed that D was a mixture
fully to give the Ortep diagram of Figure F2.
Reaction of cyclopentene (1.5 mL, 17 mmol) with Th•+SbF
-
of 9a and 10a in the ratio 5/95, that is, mainly the monoadduct,
and that E was a mixture of 9a and 10a in the ratio 95/5, that
is mainly the bisadduct. These products were again recrystal-
lized from MeCN/ether to give 206 mg of pure 9a , mp 142.5-
6
(540 mg, 1.19 mmol) in 8 mL of MeCN gave 480 mg of a
mixture of 3c and 4c in the ratio 90/10, representing 81%
•
+
-
6
recovery of Th SbF
with 77% as 3c and 4% as 4c. Workup
1
43 °C dec, from E, and 257 mg of pure 10a , mp 146-146.2
gave 3c, mp 213.5-214.5 °C dec and 4c, mp 211-212 °C dec.
1
°
C dec, from D. It is notable that, although the initial mixture
The H NMR spectra were similar to those of 3a and 4a . The
1
of 9a and 10a contained more of 9a , the amount of 9a
decreased and the amount of 10a increased during the
numerous fractional precipitations. In fact, when all of the
powdery fractions and all of the needlelike fractions were
combined, the pure, powdery 9a amounted to 206 mg and the
impure, needlelike 10a amounted to 480 mg. The reason for
this change in relative amounts of 9a and 10a is, as is shown
later, the slow conversion of 9a into 10a and Th, accounting
also for the Th that began showing up in the reprecipitations.
Single crystals of 9a and 10a were grown for X-ray crystal-
lography. An Ortep diagram for 9a was obtained and is
crystal structure of 3c was reported earlier. Anal. Calcd for
C H S Sb F12.CH CN (4c): C, 28.6; H, 2.40; S, 8.05; F, 28.6.
17 16 2 2 3
Found: C, 28.2; H, 2.37; S, 7.70; F, 27.8.
1,2-Bis(5-th ia n th r en iu m yl)cycloh exa n e Dip er ch lor a te
(6a ) a n d 1,2-(5,10-th ia n th r en iu m d iyl)cycloh exa n e Di-
p er ch lor a te (7a ). A solution of 1.80 mL (17.8 mmol) of
cyclohexene in 1.0 mL of MeCN and a suspension of 680 mg
•
+
-
4
(2.15 mmol) of Th ClO
were used. After 4 h of stirring, 560
mg of precipitate was obtained and found with NMR spectros-
copy to be solely 6a . Addition of ether to the filtrate gave 150
mg of a mixture of 6a and 7a , which was separated with
fractional precipitations and crystallization into 117 mg of 6a ,
mp 149-149.2 °C dec, and 31 mg of 7a , mp 127-128 °C dec.
The 1H NMR spectrum of 6a agreed with that of an earlier
reported here (Figure F1), but the crystals of 10a were too
1
slender to diffract. H NMR, CD
3
CN, 500 MHz: (9a ): 8.125
(8.0, 1.0, 1.0), dd, 2H; 8.112 (7.5, 1.0, 1.0), dd, 2H; 7.924 (8.0,
4
7
.5, 1.0, 1.5, 1.0), td, 2H; 7.894 (8.0, 1.0, 1.0), dd, 2H; 7.850
report. Single crystals of 7a were too slender for successful
1
(7.5, 8.0, 1.0, 1.5, 1.5), td, 2H; 7.810 (8.0, 8.0, 1.5, 1.0, 1.5), td,
X-ray diffraction. H NMR, CD
3
CN, 200 MHz (7a ): 8.613 (5.81,
2
7
H; 7.723 (7.5, 8.0, 1.5, 1.5, 8.0, 1.0, 1.0), overlapping ddd, 2H;
.661 (8.0, 1.0, 1.0), dd, 2H; 4.78, m, 2H; 2.173, m (overlap
3.31, 3.40), dd, 2H; 8.526 (5.85, 3.47, 3.47), dd, 2H; 8.200 (5.77,
3.31, 3.43), dd, 2H; 8.145 (5.86, 3.26, 3.22), dd, 2H; 4.582, m,
2H; 2.310, br d, 2H; 1.768-1.665, m, 2H; 1.553, m, 2H; 1.319,
with solvent water); 1.986, m, 2H; 1.848, m, 4H; 1.630 (6.5,
.0), t, 1H; 1.600 (8.0, 7.5), t, 1H. (10a ): 8.618 (6.0, 3.5, 3.5),
dd, 2H; 8.554 (6.0, 3.5, 3.5), dd, 2H; 8.208 (5.5, 3.5, 3.0), dd,
8
m, 2H.
Reaction of cyclohexene with Th•+PF
-
gave only the bis-
6
2
2
H; 8.144 (5.5, 3.0, 3.5), dd, 2H; 4.692 (8.0, 2.5, 2.5), dd, 2H;
.595, m, 2H; 2.042, m, 2H; 1.672, m, 1H; 1.325, m, 4H; 1.134,
adduct (6b), 90%, mp 144.5-145.5 °C dec. None of 7b could
•+
-
6
be found. Similarly, reaction with Th SbF
gave only 6c, 43%,
m, 1H. Anal. Calcd for C19
S, 12.5; Cl, 13.9. Found: C, 44.3; H, 3.64; S, 12.3; Cl, 14.1.
H
20
S
2
Cl
2
O
8
(9a ): C, 44.6; H, 3.94;
mp 176.2-177 °C dec, and none of 7c. Each of 6b and 6c had
1
a satisfactory H NMR spectrum.
•
+
-
6
Similar reactions of cycloheptene with Th PF
and
1,2-Bis(5-th ia n th r en iu m yl)-4-m eth ylcycloh exa n e Di-
Th•+SbF
-
were carried out, the objective being to obtain single
p er ch lor a te (15a ). 4-Methylcyclohexene (1.0 mL, 8.3 mmol)
6
•
+
-
4
crystals of monoadduct that, with larger anions, might diffract
and 390 mg (1.24 mmol) of Th ClO
were used in 5 mL of
successfully. In this way, we obtained 430 mg of a mixture of
MeCN. Addition of ether after 5 h gave a yellow oil which
solidified on rubbing, to give 450 mg of product. H NMR
-
1
PF
6
salts 9b and 10b in the ration 65/35. These data
represent a total yield of products of 83%, amounting to 53%
of 9b and 30% of 10b. Fractional precipitation and crystal-
lization gave 9b free of 10b (by NMR), mp 155.2-156.5 °C
dec, and 10b free of 9b, mp 159.5-161 °C dec. Use of
spectroscopy showed the presence of 15a and 16a in the ratio
95/5, representing a recovery of 99% of Th ClO , with 95%
•
+
-
4
as 15a and 4% as 16a . Attempts to separate and recover 16a
failed; only 15a could be obtained, mp 112-113 °C dec. Growth
•
+
-
Th SbF
6
gave 590 mg of a mixture of 9c and 10c in the ratio
of a single crystal for X-ray crystallography was successful
1
5
0/50, representing a total yield of 80%. Separation gave 9c,
(Figure F3). H NMR, CD
3
CN, 500 MHz (15a ): 8.118-7.705,
mp 182-183.5 °C dec, and 10c, mp 195-195.5 °C dec. Each
m, 16H; 4.284, br m, 2H; 2.323, m, 1H; 2.064-2.003, m, 1H;
1.996-1.948, m, 1H; 1.873, br d, 1H; 1.581-1.457, m, 2H;
1.317, m, 1H; 1.003 (6.5), d, 3H.
1
of these four products had a satisfacory H NMR spectrum,
similar to those reported for 9a and 10a . Unfortunately, single
crystals of 10b and 10c suitable for X-ray crystallography
could not be obtained.
5,6-Bis(5-th ia n th r en iu m yl)cycloocten e Dip er ch lor a te
(17a ). A solution of 2.72 g (25.1 mmol) of 1,5-cyclooctadiene
in 8 mL of MeCN was added dropwise to a suspension of 910
1
,2-Bis(5-th ia n th r en iu m yl)cyclop en ta n e Dip er ch lor -
•
+
-
4
a te (3a ) a n d 1,2-(5,10-Th ia n th r en iu m d iyl)cyclop en ta n e
mg (2.88 mmol) of Th ClO
in 10 mL of MeCN. After 20 min
Dip er ch lor a te (4a ). The reactants were 4.0 mL (45 mmol)
of cyclopentene and 1.48 g (4.69 mmol) of Th ClO
of MeCN. Workup gave 1.26 g of a mixture of 3a and 4a in
of stirring the yellow solution began depositing a white
precipitate. Ether (80 mL) was added after 4.5 h of stirring.
The solid was filtered, washed, and dried to give 930 mg (1.26
•
+
-
4
in 20 mL

4
036 J . Org. Chem., Vol. 67, No. 12, 2002
Qian et al.
Th•+ClO
-
in CD
CN. It was necessary to wait for 35 min
mmol, 88%) of 17a . A monoadduct was not obtained. Crystal-
4
3
lization from MeCN/ether gave mp 115-116 °C dec. Single-
before an NMR spectrum could be obtained. At that time the
color of the solution was pink and the NMR signals of Th were
broadened. The relative amounts of 20 and 21 were obtained
by integrating the methyl-group triplets and was 10/90. After
95 min the solution was colorless, the signals from Th were
in their proper field, signals from ThO were observable, and
the dominant signals were from 21. Integration of methyl-
group triplets gave a ratio 20:21 of 10/90. After 3 h, the NMR
spectrum was essentially the same and integration of the
methyl-group triplets gave a ratio 5/95. After the lapse of 1
1
crystal growing was successful (Figure F4). H NMR, CD
3
CN,
5
00 MHz (17a ): 8.096 (8.0, 1.0, 1.0), dd, 2H; 8.043-8.022, br
dd, 2H; 7.933 (7.75, 7.75, 1.5, 1.0, 1.5), td, 2H; 7.881 (8.0,
1
7
.25, 1.5, 0.5), ddd, 2H; 7.851 (7.0, 8.25, 1.0, 1.0, 1.0), td, 2H;
.786 (7.5, 8.8, 1.0, 1.0, 1.0), td, 2H; overlapping dd, 7.748
(
(
7.75, 2.0, 1.5), dd, 1H; 7.734 (8.0, 2.0, 2.0), dd, 1H; 7.685
8.0, 1.0, 1.0), dd, 2H; 5.973 (4.0, 4.0), br t, 2H; 4.442 (5.75,
6
.0), br t, 2H; 2.840 (15.5, 15.0), br t, 2H; 2.518-2.456 (4.0),
two br q, 2H; 2.173-2.107, br m, overlapping solvent; 2.089-
2
.039, m, 2H.
day, the signals from 20 were no longer visible.
1
th r eo-2,3-Bis(5-th ia n th r en iu m yl)bu ta n e Dip er ch lor a te
3
H NMR, CD CN, 500 MHz (21): Despite the apparent
(
18) a n d er yth r o-2,3-(5,10-Th ia n th r en iu m d iyl)bu ta n e Di-
symmetry of 21 the NMR spectrum was complex and indicative
of long-range, virtual couplings. 8.629-8.599, m, 4H; 8.181-
6
p er ch lor a te (19). A stream of cis-2-butene was bubbled into
a suspension of 480 mg (1.52 mmol) of Th ClO
MeCN cooled in an ice bath until the color of Th had faded
to light pink, about 30 min. A white precipitate had formed.
After addition of 60 mL of dry ether the precipitate was
recovered, giving 420 mg of a mixture of 18 and 19 in the ratio
•
+
-
4
in 8 mL of
8.153, m, 4H; 4.114, m with 11 lines visible suggestive of dtd
(7.5, 5.25, 3.5), 2H; 2.0-1.96, m overlapping solvent, 2H; 1.62-
1.53, m with 12 lines visible suggestive of ddq (16.0, 7.0, 7.0),
2H; 1.200 (7.25), t, 6H. 13C NMR (21): 137.598, 137.547,
137.531, 137.243, 125.735, 122.457, 62.488, 26.747, 11.476.
It was not possible to obtain a complete NMR spectrum of
20.
•
+
(NMR) 95/5. This ratio corresponds with 0.59 mmol (78% of
•
+
•+
Th units) of 18 and 0.031 mmol (2.0% of Th units) of 19.
GC assay of the filtrate gave 0.357 mmol of Th, an amount
which is larger than equatable to the yield of 19 and most of
which is attributable to the GC decomposition of 18 and 19
remaining in solution. Pure 18 was obtained by successive
precipitations from MeCN with ether and crystallization from
MeCN/ether, mp 169.5-170 °C dec. Growth of a single crystal
for X-ray crystallography was successful (Figure F5). Separa-
tion of pure 19 was not successful. Adduct 18 changed slowly
into 19 in MeCN solution.
th r eo-2,3-Bis(5-th ia n th r en iu m yl)-4-m eth ylp en ta n e Di-
p er ch lor a te (22) a n d er yth r o-2,3-(5,10-Th ia n th r en iu m -
d iyl)-4-m eth ylp en ta n e Dip er ch lor a te (23). To a stirred
•
+
-
4
suspension of 500 mg (1.58 mmol) of Th ClO
in 8 mL of
MeCN was added dropwise 1.5 mL (12 mmol) of 4-methyl-cis-
2-pentene. The solution was pale yellow after 30 min and had
no precipitated solid. Addition of 60 mL of ether caused
precipitation of white solid which was recovered to give 410
mg of a mixture of 22 and 23 in the ratio 80/20. This represents
•
+
An NMR spectrum of the mixture of 18 and 19 had clearly
separated spectra of the two adducts although the alkyl signals
from 19 were not strong enough to be integratable. H NMR,
0.488 mmol (62% of initial Th units) of 22 and 0.122 mmol
•+
(7.7% of Th units) of 23. GC analysis of the filtrate gave 0.39
1
•+
mmol (25% of Th units) of Th. The data account for 95% of
•
+
-
4
CD
3
CN, 500 MHz (18): 8.102 (8.0, 0.5), dd, 2H; 8.042 (8.0, 1.0),
Th ClO . Separation of the adducts by precipitations and
dd, 2H; 7.921 (7.8 ave, 1.5), td, 2H; 7.870, m of overlapping dd
and td, 4H; 7.765 (7.75, 1.3 ave), td, 2H; 7.738 (8.0, 2.0), dd,
crystallization gave 340 mg (0.476 mmol) of 22, mp 118-119
°C dec, and 44 mg (0.088 mmol) of 23, mp 95-97 °C dec. An
1
2
H; 7.725 (8.0, 2.0), dd, 2H; 4.349 (6.8 ave), q, 2H; 1.396 (7.0),
Ortep diagram of 22 (Figure F7) was obtained. H NMR, CD
3
-
1
3
d, 6H. C NMR (18): 136.987, 136.675, 136.632, 136.442,
CN, 500 MHz (22): 8.205 (8.5), d, 1H; 8.105 (7.75), d, 1H;
8.057-7.964, m, 4H; 7.865-7.776, m, 8H; 7.750-7.716, m, 2H;
4.489 (1.75 ave), t, 1H; 4.262 (7.1 ave, 1.75 ave), qd, 1H; 2.696
(7.0), hept, 1H; 1.465 (7.0), d, 3H; 1.441 (7.0), d, 3H; 0.642 (7.0),
1
1
8
8
1
1
36.324, 135.984, 131.901, 131.616, 131.518, 131.146, 115.361,
15.728, 47.399, 11.509. H NMR, CD CN, 500 MHz (19):
3
.612 (5.5, 3.5), dd; 8.525 (6.0, 3.5), dd; 8.194 (6.0, 3.5), dd;
.126 (5.75, 2.75), dd; 4.734, m; 1.453 (7.0), d. 13C NMR (19):
37.975, 137.844, 137.165, 136.490, 126.474, 123.347, 53.983,
4.267.
1
13
d, 3H. C NMR (22): 28 of possible 30 peaks were obtained:
138.065, 137.315, 137.090, 136.865, 136.770, 136.742, 136.703,
136.612, 136.300, 136.241, 136.142, 132.402, 132.300, 132.264,
132.161, 132.051, 131.672, 131.648, 131.206, 116.068, 115.563,
115.346, 55.191, 48.730, 28.783, 21.962, 19.636, 12.618. The
larger intensities of peaks at 136.612 and 115.346 ppm
suggested that each represented two C atoms with the same
chemical shift.
er yth r o-3,4-Bis(5-th ia n th r en iu m yl)h exa n e Dip er ch lo-
r a te (20) a n d th r eo-3,4-(5,10-Th ia n th r en iu m d iyl)h exa n e
Dip er ch lor a te (21). (A) To a suspension of 740 mg (2.34
•
+
-
4
mmol) of Th ClO
in 8 mL of MeCN was added 2.0 mL (12
mmol) of trans-3-hexene. The color of the solution was purple
after 1 h, but after 6 h of stirring the now colorless solution
had deposited a white precipitate. More precipitation occurred
on adding 50 mL of ether. Workup gave 360 mg (0.72 mmol,
Kingsbury and Best5 have reported that the coupling (3.5-
3.7 Hz) between protons on carbon atoms C and C in threo
2 3
isomers of 2,3-dibromo- and 2,3-dichloro-4-methylpentane is
smaller than that (10.6 Hz) in the erythro isomers. In analogy,
•
+
3
1% of Th units) of 21. A bisadduct (20) was not detectable
with NMR spectroscopy. Single-crystal growth for X-ray
the small coupling (1.75 Hz) of the corresponding atoms in 22
1
crystallography was successful (Figure F6), mp 153-154 °C
is suited to a threo isomer. H NMR, CD
3
CN, 500 MHz (23):
(expl).
8.679-8.660, m, 1H; 8.612-8.594, m, 1H; 8.577-8.543, m, 2H;
8.188-8.169, m, 2H; 8.131-8.109, m 2H; 5.058 (7.4 ave), quint,
1H; 4.302 (8.0), t, 1H; 2.28-2.21, m overlapping solvent; 1.415
(7.5), d, 3H; 1.303 (6.5), d, 3H; 1.185 (6.5), d, 3H. The quintet
at 5.058 ppm and the triplet at 4.302 ppm are attributable to
(
B) A similar experiment was carried out with 311 mg (0.984
•
+
-
4
mmol) of Th ClO
and had faded to light pink and a white
precipitate had formed. Workup after addition of 30 mL of
ether gave 168 mg of a mixture of 20 and 21 in the ratio
averaging 7/93 from integrations of aromatic and alkane
2 3
the protons on C and C , and their large coupling constants
•+
-
5,7,8
protons. This represents stoichiometric conversions of Th ClO
4
are suited to cis-related, erythro protons.
into 5% of 20 and 67% of 21. Assay of the filtrate gave 0.60
mmol of Th, an excessive amount arising from decomposition
in the GC of adducts remaining in solution. Decomposition to
give Th on injection into the GC inlet was confirmed indepen-
dently. Successive precipitations of the mixture of adducts gave
Monoadduct 23 was sufficiently unstable in MeCN as to
interfere with long-time acquisition of 13C NMR data.
Con ver sion s of Bis- (9 a n d 18) in to Mon oa d d u cts (10
a n d 19). Experiments were carried out mostly with 9a and
9c. The conversions into 10a and 10b were monitored daily
for 8 to 10 days with NMR spectroscopy. On each day of
measurement, the complete NMR spectrum was recorded. The
relative amounts of 9 and 10 were measured in two ways. The
pair of aromatic dd in the spectrum of 10 that was furthest
downfield (8.55-8.60 ppm) and was always separated cleanly
from any other NMR signals was used as a standard repre-
senting 4H. In the region 8.1-8.2 ppm the second pair of 4H
1
33 mg (0.266 mmol) of 21, mp 160-160.5 °C (expl) and 14.4
mg of a mixture containing 0.011 mmol of 20 and 0.013 mmol
of 21. We were unable to prepare a pure sample of 20, which
changed slowly into 21 in solution.
(
C) This experiment was carried out in an NMR tube
shielded from light with foil except for brief periods when in
the probe. The trans-3-hexene was added to a suspension of

Addition of Thianthrene Cation Radical Salts to Cycloalkenes
J . Org. Chem., Vol. 67, No. 12, 2002 4037
dd of 10 partly overlapped the furthest downfield aromatic 4H
multiplet of 9. Integration of this overlapped region allowed
for the calculation of that part of the overlap due to 9 and, by
difference, that due to 10. The data thus allowed for the
calculation of the relative amounts of 9 and 10. The signals
from the two CH protons in 9 and 10 were integrated as an
overlapping multiplet. The part of the multiplet attributable
to 10 was assessed as 2H (relative to the 4H standard of 10),
so that the balance of the integrated multiplet could be
attributed to 9 and thus provide a second measure of the
relative amounts of 9 and 10. These data were translated into
first-order rates of conversion from calculations of the concen-
tration of 9 given by the ratios at the timed intervals.
daily were much like those obtained with 9c. That is, integra-
tions of 10a equated to those of Th. The signals from Th were
well defined and none from ThO were seen. The ratios 9a :10a
after 1, 2, 3, 4, 6, 8, and 10 d were 83/17, 67/33, 58/42, 45/55,
-
3
-1
32/68, 22/78, and 18/82; rate k ) 8.0 ( 0.3 × 10
h , r )
0.9978.
(E ) Wit h 9a a n d Ad d ed Th •+ClO4- in t h e Da r k . To a
solution of 7.7 mg (0.0106 mmol) of 9a in 1.0 mL of CD CN
3
•
+
-
was added 2.7 mg (0.0085 mmol) of Th ClO4 . After 1 d,
signals from 10a were pronounced, but none of Th could be
seen. This pattern continued until the third day when a
shallow band for Th appeared at 7.1-7.4 ppm. After 4 d, the
broad band for Th was intensified and signals from ThO were
evident among those from 9a . The signals from ThO and the
intensity of the band spanning 7.3-7.5 ppm increased with
time, until after 6 d they dominated the upfield aromatic
region. At all times, the spectrum of 10a was well defined.
Assays of the ratio 9a :10a were made with the overlapped CH
Three separate runs (two with 9a and one with 9c) were
made in NMR tubes that were shielded from light except for
the brief time in the NMR probe. One run was made with 9c
in an unshielded NMR tube, one run was made with a solution
of 9c that contained added Th, and three (two with 9a and
one with 9c) runs were made in the dark with solutions
multiplets and after 1, 2, 3, 4, 6, and 8 d were 80/20, 68/32,
containing added Th•+ClO
-
. The replicated runs had the same
-3 -1
4
62/38, 54/46, 34/66, and 20/80: k ) 8.2 ( 0.67 × 10
h , r )
character so that details are given only for single examples.
A) With 9c in th e Da r k . The NMR tube, shielded with
metal foil contained a solution of 9.0 mg (0.009 mmol) of 9c in
.5 mL of CD CN. Within a few hours, the peaks of 10c and
0.9867.
(
(
F ) Th e E ffect of Ad d ed Th on t h e Ad d it ion of
•+
-
Th ClO
4
to Cycloh ep ten e. Three suspensions (A, B, and
1
3
•+
-
4
C) were made, each of 300 mg (0.95 mmol) of Th ClO
in 8
Th were discernible. After 2 d, with the standard for 10c set
as 4H, the two separate and clear multiplets of Th at 7.55 and
mL of MeCN. In B and C the solvent contained 0.25 and 0.125
mmol, respectively, of dissolved Th. To each stirred suspension
was added 1.5 mL of cycloheptene. The suspensions became
colorless within a few min. After a further 5 min, 40 mL of
ether was added. The precipitates were collected and weighed,
respectively, 190, 210, and 190 mg. The NMR ratios 9a :10a
were 65/35, 67/33, and 68/32, respectively.
7
.30 ppm integrated as 4.1H each. This character was repeated
in NMR spectra recorded for 8 d. As the concentration of Th
increased, the definition of its pairs of dd became more
pronounced. On each day of measurement, the integral for Th
was the same as that for 10c. On days 3-8, the spectra of Th
and 10c were very well resolved. The solution remained
colorless throughout the run. The ratios 9c:10c were calculated
after 10 h, 1, 2, 3, 6, and 8 d, and were, respectively, 93/6,
(
G) Th e Absen ce of Rea ction betw een 10a a n d Th . A
solution of 7.9 mg (0.015 mmol) of 10a and 7.7 mg (0.035 mmol)
of Th in 1.0 mL of CD CN was kept in an NMR tube shielded
from light. The NMR spectrum was recorded periodically for
d during which time signals from 9a were not observed.
H) Th e Effect of Ligh t on Solu tion s of 9a . A. A solution
3
-
3
7
h
3/27, 62/38, 48/52, 28/72, and 14/86; k ) 9.6 ( 0.5 × 10
-1
, r ) 0.9936.
B) With 9c in th e Ligh t. The solution contained 8.0 mg
CN. The NMR tube was
6
(
(
(0.008 mmol) of 9c in 1.5 mL of CD
3
of 17.3 mg (0.0238 mmol) of 9a in 3 mL of MeCN in a cuvette
was exposed periodically to fluorescent light and daylight
during several days. The absorbance at 540 nm, characteristic
unshielded and was illuminated with laboratory natural and
fluorescent light. A light pink color appeared soon after
exposure to light and remained during the 11 d of the
experiment. The intensity of the color diminished during
overnight darkness and re-appeared in daylight. Optical
density measurements were not made on this solution, but
were recorded in separate experiments.
•
+
of Th , was recorded daily, increasing when lights were on
and decreasing when they were off. The maximum concentra-
•
+
tion of Th that was reached was calculated with the use of
•
+
the extinction coefficient for Th in concentrated sulfuric
acid,12 and amounted to 3.4% of the initial amount of 9a . B. A
similar solution was exposed to daylight for 14 h. The absorp-
tion spectrum had maxima at 539, 915, and 1032 nm,
Within a few hours, the appearance of 10c was evident, but
peaks of the Th spectrum were not seen. After 1 d, the signals
from 10c were pronounced and well resolved, but in the region
of 7.3 ppm for Th only a broadening of the baseline could be
seen. The ratio 9c:10c was then 72/28. This behavior continued
during 8 d of measurement. Thus, after 5 d the signals from
Th appeared as abroad hump spanning 7.1-7.6 ppm, whereas
those from 10c were cleanly defined sets of dd. After the eighth
day, well-defined peaks of ThO were found, overlapping in part
the broad hump for Th spanning 7.3-7.6 ppm. On the 11th
day, the spectrum of ThO was clearly defined, whereas that
for Th was again a broad band. The spectrum of 9c was no
longer discernible. The ratio 9c:10c after 10 h, 1, 2, 3, 5, 6,
and 8 d was 94/6, 72/28, 57/43, 43/57, 24/76, 19/81 and 7/93; k
•
+
characteristic of Th . Using extinction coefficients for these
1
2
•+
wavelengths, the concentration of Th was found to be 7.9
-
5
×
10 M, namely 1% of the initial amount of 9a .
I) ESR Exp er im en ts w ith 9a . A 300 MHz spectrometer
(
was used. Because of dielectric loss by the polar solvent, a
sample was placed in a 1 mm capillary tube within a 4 mm
esr tube. A control spectrum was recorded with a solution of
•
+
-
6
Th PF
3 3
in CD CN. The test solutions were of 9a in CD CN,
each approximately 8 mM. A solution of 9a that had been
sealed for 5 d in an ampule protected from light was colorless
when opened for esr scanning. An esr signal could not be found.
The capillary was exposed to laboratory fluorescent light, and
its solution became pink within 1 h. After 3 h, the esr spectrum
was like that of the control. A second ampule containing a
-
3
-1
)
11.5 ( 0.18 × 10
C) With 9c a n d Ad d ed Th in th e Da r k . The solution
contained 8.4 mg (0.0084 mmol) of 9c and 4.0 mg (0.0019
mmol) of Th in 1.5 mL of CD CN. Two well-defined dd of Th
h , r ) 0.9995.
(
1
-day-old, colorless solution that had been protected from light
3
was exposed to laboratory light. The solution became pink
within 1 h, and the color intensified on standing. The ampule
was opened after 3 h, and its solution gave an esr signal
identical with that of the control. All esr signals were single
lines of approximately 3 G width. The g-values, calculated from
the microwave frequency and field strength, were 2.0066 for
the control and 2.0065 for the light-exposed ampule. The
magnetic field was not calibrated with use of another radical
were evident at 7.52 and 7.30 ppm throughout the whole of
this run. That is, no broadening of the Th peaks was observed
at any time. In all integrations those of the two Th dd were
equal and, obviously, greater than that of the 10c standard.
For example, after 3 d, the two Th dd represented 21.7 and
2
2.5 H as compared with the 4H standard. Absolute yields of
1
0c and newly formed Th were not calculated. Ratios 9c:10c
after 10 h, 1, 3, 5, 6, and 8 d were, respectively, 95/5, 73/27,
•
+
-
3
-1
standard. The esr spectrum of Th in concd sulfuric acid has
4
0
7/53, 33/67, 27/73, and 15/85; k ) 9.3 ( 0.4 × 10
h , r )
1
0,12
five lines of 1.3 G width, spans 5 G, and has g ) 2.0081.
.9963.
(
D) With 9a in th e Da r k . A solution of 8.2 mg (0.011 mmol)
of 9a in 1.0 mL of CD CN was used. The NMR spectra recorded
3
(12) Shine, H. J .; Piette, L. J . Am. Chem. Soc. 1962, 84, 4798-4806.

4
038 J . Org. Chem., Vol. 67, No. 12, 2002
Qian et al.
The signals recorded in CD
exchange narrowing and loss of hyperfine splitting.
J ) With 18 in th e Da r k . As in part A with 9c, the solution
3
CN solution appear to exhibit spin-
0.1 mL of D
2
O was added, and after a further 3 d the ratio of
1
3
components was 10/80/10. After 8 d, only 11c and Th were
found, in the ratio 90/10.
(
contained 8.3 mg (0.012 mmol) of 18. Two days elapsed before
enough of 19 for integration had formed. Th had formed, and
its signals were not broadened. Integrations of the relative
amounts of 18 and 19 were made in three NMR regions,
namely, the aromatic multiplets spanning 8.63-8.51 and
Con ver sion of 7a in to 8a . Effect of Wa ter . (A) In Dr y
CD CN. A solution of a small amount of 7a in 1.0 mL of
3
CD CN was monitored with NMR spectroscopy. The relative
3
amounts of 7a , 8a , and Th were assayed through integration
of unoverlapping parts of their aromatic signals. That is, for
7a we used the multiplet (4H) in the region 8.643-8.512 ppm,
for 8a the multiplet (6H) in the region 7.948-7.687 ppm, and
for Th the multiplet (4H) in the region 7.359-7.294 ppm. After
13 d signals from 7a could not be seen, while 8a and Th had
been formed in the ratio 35/65. GC analysis of the solution
showed the presence of 1,3-cyclohexadiene, but quantitative
assay was not made.
8
4
.21-8.03 ppm, the methine multiplets centered at 4.73 and
.32 ppm, and the methyl doublets at 1.45 and 1.39 ppm. The
three ratio measurements were averaged. The methyl 6 H
doublet for 18 at 1.39 ppm was used as the integration
standard. The ratio 18:19 after 2, 4, 6, 8, 10, and 12 d was
8
1
9/11, 82/18, 73/27, 65/35, 60/40, and 52/58; k ) 2.6 ( 0.14 ×
-3 -1
0
h
, r ) 0.9945.
K) With 18 in th e Ligh t. The procedure was like that with
c. The solution (8.0 mg, 0.0116 mmol, in 1.0 mL) became pink
(
(B) In Wet CD CN. Isola tion of 8a . To a solution of 6.7
3
9
mg (1.35 mmol) of 7a in 1.0 mL of CD CN was added 0.2 mL
3
within a few hours. The NMR signals from 18 and 19 were
distinct, but none was seen from Th. Integrations were again
made at 2, 4, and 6 d intervals. During this time the spectrum
of 19 was unaccompanied by any other monoadduct signals.
After 6 d, small peaks of ThO were found as well as of a new
multiplet at 5.45 ppm and doublet at 1.57 ppm. These changes
were not followed further. The ratio 18:19 after 2, 4, 6, 8, 10,
and 12 d was 87/13, 77/23, 67/33, 60/40, 55/45, and 45/55; k )
of D O. After 18 h, 7a could no longer be detected, while 8a
2
and Th had been formed in the ratio 85/15. The CD CN was
3
evaporated with an air jet and the residue was washed three
times with ether to remove Th. The remaining solid was
dissolved in CD CN and was found with NMR spectroscopy
3
to be free of Th. A small amount of ether was added to cause
crystallization of 8a , mp 227-228 °C dec. A single crystal was
1
grown successfully for X-ray crystallography (Figure F8). H
-
3
-1
2
.6 ( 0.14 × 10
L) Attem p ted Con ver sion of 6a in to 7a in CD
solution of 6a in CD CN was monitored daily with NMR
h
.
NMR, CD CN, 500 MHz (8a ): 8.109 (8.0, 1.5, 1.5), dd, 2H;
3
(
3
CN. A
7.919 (8.0, 1.5, 0.5, 0.5, 1.5, 0.5, 0.5), ddd, 2H; 7.830 (7.5, 8.0,
1.5, 1.5, 8.0, 1.5, 1.5), overlapping ddd, 2H; 7.722 (8.0, 7.5, 1.0,
1.0, 7.5, 1.0, 1.0), overlapping ddd, 2H; 6.021 (4.0, 1.5), tt, 1H;
2.170-2.127, m, 2H; 1.909-1.886, m, 2H; 1.662-1.614, m, 2H;
1.528-1.481, m, 2H.
3
spectroscopy for 6 d during which time 7a could not be
detected.
F or m a tion of 1-(Th ia n th r en iu m yl)cycloa lk en es. Con -
ver sion of 10a in to 11a . (A) In CD
small amount of 10a in 1.0 mL of CD
3
CN. To a solution of a
CN was added 0.2 mL
Con ver sion of 4a in to 5a . Isola tion of 5a . A solution of
3
a small amount of 4a in 1.0 mL of CD CN containing 0.2 mL
3
of D
2
O. The NMR spectrum was monitored to follow the
of D O was monitored periodically with NMR spectroscopy for
2
+
conversion of 10a (two CH-S protons) into 11a (one alkenyl
proton). The conversion was complete after 7 d, after which
signals from 10a were no longer seen. Some Th had been
formed, too, and the integrated ratio 11a :Th was 95/5.
assay of 4a , 5a , and Th. After 2 d, for example, the ratio of
these compounds was, respectively, 90/8/3, and after 31 d 20/
43/38. Finally, after 64 d, the amount of 4a was too small to
measure, while the ratio 5a :Th was 55/45. The solution was
(
B) In MeCN. Isola tion of 11a . To a solution of 130 mg
treated as described earlier to give 5a , mp 241-242 °C dec.
1
(
0.255 mmol) of 10a in 6 mL of MeCN was added 0.5 mL of
3
H NMR, 200 MHz, CDCl (5a ): 8.135 (7.82, 1.50, 1.52), dd,
water. The solution was stirred for 7 d, after which ether was
added to precipitate 73 mg (70%) of white solid, mp 157-163
2H; 7.925 (7.80, 1.51, 1.41), dd, 2H; 7.827 (7.40, 7.82, 1.52,
1.53, 1.56), td, 2H; 7.715 (7.62, 7.47, 1.81, 1.60, 1.55), td, 2H;
6.183, m, 1H; 2.454, m, 2H; 2.279, m, 2H; 2.046-1.976, m
(overlapping solvent).
°
C dec. Crystallization from MeCN/ether gave 11a , mp 171-
1
1
1
7
5
2
3
72 °C dec. H NMR, CD CN, 500 MHz (11a ): 8.402 (7.75,
.0, 1.5), dd, 2H; 7.823 (7.9, 1.0,1.25, 0.5), ddd, 2H; 7.777 (7.5,
.75, 1.5, 1.5, 1.0), td, 2H; 7.721 (8.0, 7.5, 1.5, 1.5, 1.5), td, 2H;
.904 (7.0, 6.5), t, 1H; 2.337 (2.2, 2.2), t, 2H; 2.271 (2.6, 2.0,
.6), q, 2H; 1.672, m, 2H; 1.494, m, 2H; 1.359, m, 2H. Anal.
Con ver sion of 13a in to 14a . Isola tion of 14a . The
1
preparation of 13a has been reported earlier. A control NMR
experiment showed that 13a in 1.0 mL of CD
3
CN containing
O was converted into 14a and Th in the ratio 80/
0 completely after 1 d. Therefore, a solution of 61.8 mg (0.118
0
2
.2 mL of D
2
Calcd for C19
19 2 4
H S ClO (11a ): C, 55.5; H, 4.66; S, 15.6; Cl, 8.63.
Found: C, 55.5; H, 4.43; S, 15.5; Cl, 9.02.
mmol) of 13a in 4 mL of MeCN and 0.5 mL of water was stirred
for 1 d, after which ether was added to precipitate 33.8 mg
(0.0796 mmol, 67.5%) of product, mp 173.5-175 °C after
Con ver sion of a Mixtu r e of 9b a n d 10b in to 11b in
MeCN. Isola tion of 11b. A solution of 200 mg of a mixture
of 9b and 10b, ratio 10/90, was dissolved in 5 mL of MeCN.
After 14 d, ether was added to precipitate 8.8 mg of solid, mp
1
crystallization from MeCN/ether. H NMR, CD CN, 500 MHz
3
(14a ): 8.158 (8.0, 1.0,1.0), dd, 2H; 7.932 (8.0, 0.5, 0.5), dd, 2H;
7.851 (8.25, 8.0, 1.5, 1.5, 7.5, 1.5, 1.5), overlapping ddd, 2H;
7.737 (7.5, 8.0, 1.5, 1.5, 8.0, 1.5, 1.5), overlapping ddd, 2H;
5.759 (8.5, 8.5), t, 1H; 2.475, m, 2H; 2.249-2.207, m, 2H;
1.545-1.497, m, 2H; 1.391-1.307, m, 4H; 0.982-0.935, m, 2H.
Anal. Calcd for C H S ClO (14a ): C, 56.5; H, 4.98; S, 15.1;
1
69.5-171 °C dec, deduced to be 11b from the NMR spectrum.
1
H NMR, CD
3
CN, 500 MHz (11b): 8.136 (8.0, 1.5, 0.5), ddd,
2
1
1
2
1
H; 7.939 (8.0, 1.0, 0.5), ddd, 2H; 8.845 (7.5, 8.0, 1.5, 1.5, 8.0,
.5, 1.5), overlapping ddd, 2H; 7.741 (7.25, 8.0, 1.5, 1.5, 7.5,
.5, 1.0), overlapping ddd, 2H; 5.953 (7.0, 6.5), t, 1H; 2.298-
.229, m, 4H; 1.687-1.639, m, 2H; 1.476-1.430, m, 2H; 1.292-
.246, m, 2H.
2
0
21
2
4
Cl, 8.34. Found: C, 56.8; H, 5.20; S, 15.0; Cl, 8.35.
Rea ction s of Ad d u cts w ith Sod iu m Th iop h en oxid e in
MeCN. The general procedure was to stir overnight a solution
of the reactants in MeCN containing a GC standard in a
septum-capped or sealed vessel. The mmolar amount of PhSNa
always exceeded that of the adduct. Naphthalene was used
as GC standard with column A for reactions of 6a , 9a , 10a ,
and 17a . Both naphthalene (col A) and 2-butanone (col B) were
used for reaction of 3a . The number of assays was 3-5, and
averaged results are reported. A detailed example is given with
9a .
Con ver sion of 9c in to 10c a n d 11c in CD
3
CN. Effect of
CN was
Wa ter . (A) In Dr y CD CN. A solution of 9c in CD
3
3
monitored with NMR spectroscopy. Conversion into 10c was
detected during the first day and after 6 d the ratio of 9c:10c
was 20/80. Soon, 11c began to appear, and after 16 d, when
9
c was not detected, the ratio 10c:11c was 80/20.
B) In Wet CD CN. A separate solution of 10c in CD
was monitored for 3 d. No 11c but a small amount of Th was
detected. Two drops of D O was added to the NMR tube. After
a further 3 d, the ratio 10c:11c:Th was 60/35/5. At that time,
(
3
3
CN
2
A solution of 56.7 mg (0.0779 mmol) of 9a and 37.7 mg (0.285
mmol) of PhSNa was stirred overnight. GC analysis gave
0
.0779 mmol (100%) of cycloheptene, 0.00423 mmol (5.4%) of
(
13) Bersohn, M.; Baird, J . C. An Introduction to Paramagnetic
Resonance; Benjamin: New York, 1996; p 54.
1-(phenylthio)cycloheptene, 0.155 mmol (99%) of Th, and 0.115

Addition of Thianthrene Cation Radical Salts to Cycloalkenes
J . Org. Chem., Vol. 67, No. 12, 2002 4039
mmol (148%) of diphenyl disulfide (DPDS), based on the
amount of 9a .
of aqueous NaOH solution and extracted with ether. Drying
(MgSO ) and workup of the ether solution gave a residue which
4
Reaction of 10a gave 93% of cycloheptene, 4.3% of 1-(phe-
nylthio)cycloheptene, 94% of Th, and 103% of DPDS. Reaction
of 6a gave 99% of cyclohexene, 2.4% of 1-(phenylthio)cyclo-
hexene, 93% of Th, and 109% of DPDS. Reaction of 3a gave
was separated with chromatography on a column of silica gel
and elution with petroleum ether. The eluates were monitored
with thin-layer-chromatography on commercial silica gel
indicator plates. Workup of appropriate eluate fractions gave,
finally: (a) 140 mg (0.739 mmol, 9.8%) of 1-(phenylthio)-
cyclopentene as an oil whose NMR spectrum complemented
that of authentic 1-(phenylthio)cyclopentene, (b) 130 mg (0.795
6
.0% of cyclopentene, 25% of 1-(phenylthio)cyclopentene, 69%
of 1,2-trans- di(phenylthio)cyclopentane, 101% of Th, and 42%
of DPDS.
Reaction of 17a with PhSNa was carried out in the usual
way. GC assay gave 95% of 1,5-cyclooctadiene, 97% of Th, and
1
mmol, 9.1%) of 3-(phenylthio)cyclopentene as an oil, H NMR,
CDCl , 200 MHz: 7.421-7.197, m, 5H; 5.913-5.867, m (7
3
9
9% of DPDS. Following GC assay, the solution (10 mL) was
peaks), 1H; 5.818-5.761, m (7 peaks), 1H; 4.330-4.271, m,
1H; 2.424-2.278, m, 3H; 2.087-1.945, m, 1H. Literature bp
poured into 15 mL of NaOH solution, and this was extracted
three times with 10 mL of ether. The residue from workup of
the ether solution was assayed in MeCN with GC and gave
190 °C/15 mmHg,16 and (c) 870 mg (2.94 mmol, 36%) of trans-
1
1,2-di(phenylthio)cyclopentane, mp 39-40 °C. H NMR, CDCl
3
,
9
5% of Th and 89% of DPDS.
200 MHz: 7.304-7.059, m, 10H; 3.593-3.548, two m, 2H;
P r epar ation of 1-(P h en ylth io)cycloh epten e. To a stirred
2.412-2.272, m, 2H; 1.944-1.661, m, 4H. Mass spectrum,
solution of 2.3 g (20 mmol) of cycloheptanone and 2.2 g of
thiophenol (20 mmol) in 20 mL of dichloromethane (CH Cl
was added 5.7 g (40 mmol) of P . The mixture was stirred
for 18 h, the supernatant solution was decanted and the
residue washed with CH Cl . The combined CH Cl solution
was washed with 10% NaOH solution. After drying (K CO
and evaporation of the CH Cl , the residue was distilled to
Calcd for C17
% abundance: 286 (M ), 16; 177 (M - C S), 100; 131 (M -
6 5
2C ), 20; 109 (C S), 16; 67 (M - 2C H -H), 42.
18 2
H S : 286.084996. Found: 286.084748. Mass,
+
2
2
)
6
H
5
2
O
5
6
H
5
6
H
5
X-r a y Cr ysta llogr a p h y. A crystal was encapsulated in a
thin shell of epoxy cement and mounted on the tip of a glass
fiber. Data were collected with a Bruker AXS automated CCD
diffractometer using the Bruker AXS package and using Mo
KR radiation (λ ) 0.71069 Å). The structure was solved by
direct methods. All non-hydrogen atoms were refined with
anisotropic displacement parameters, and hydrogen atoms
were calculated in ideal positions (riding model). Refinement
of F2 against all reflections. The weighted R-factor wR and
2
2
2
2
2
3
)
2
2
give 2.36 g (11.6 mmol, 58%) of product, bp 188-193 °C/140
1
4
mmHg; lit. bp 105-110 °C/0.005 mmHg. GC on col A showed
the presence of a minor impurity, which was removed with
chromatography on a column of silica gel, petroleum ether
1
elution. H NMR, CDCl
(
3
, 200 MHz: 7.340-7.171, m, 5H; 6.154
2
6.62, 6.58), t, 1H; 2.348 (5.53, 5.37), t, 2H; 2.198, m, 2H; 1.734,
m, 2H; 1.538, m, 4H.
-(P h en ylth io)cycloh exen e was prepared similarly in
5% yield, bp 170-176 °C/55 mmHg; lit. bp 115 °C/0.1
goodness of fit S are based on F , conventional R-factors are
2
based on F, with F set to zero for negative F . The threshold
2
2
1
expression of F > 2σ(F ) is used only for calculating R-factors-
7
(gt) etc., and is not relevant to the choice of reflections for
1
51
2
mmHg. H NMR, CDCl
.067, m, 1H; 2.178-2.102, m, 4H; 1.708-1.566, m, 4H
overlapped with solvent water.
-(P h en ylth io)cyclop en ten e was prepared analogously in
7% yield. The product (5.9 g) was distilled three times, bp
3
, 200 MHz: 7.335-7.180, m, 5H;
refinement. R-factors based on F are statistically about twice
6
as large as those based on F, and R-factors based on all data
will be even larger. All software used is contained in the
SHELXTL 5.1017 program library.
1
6
1
1
5
Ack n ow led gm en t. H.J .S. thanks the Robert A.
Welch Foundation for support (Grant D-0028). K.W.H.
thanks the Welch Foundation for support (Grant C-0976),
and for the purchase of the CCD, and the National
Science Foundation for support (Grant CHE-9983352).
H.J .S. thanks Dr. Ben A. Shoulders and Mr. Steve
Sorey, University of Texas, Austin, for hospitality and
help with the esr experiments, Dr. J ohn N. Marx for
numerous discussions of NMR spectra, and Dr. Robert
A. Holwerda for use of his kinetics software.
76-179 °C/115 mmHg; lit. bp 110 °C/0.1 mmHg, 85 °C/0.2
1
4
mmHg. GC showed the presence (4%) of an impurity, which
1
was removed with chromatography on silica gel. H NMR,
CDCl
.440-2.352, m, 4H; 2.033-1.923, m, 2H.
P r ep a r a tion a n d Sep a r a tion of 1-, a n d 3-(P h en ylth io)-
3
, 200 MHz: 7.413-7.251, m, 5H; 5.736-5.709, br m, 1H;
2
cyclop en ten e a n d tr a n s-1,2-(Dip h en ylth io)cyclop en ta n e.
In a pressure tube were placed 1.13 g (8.13 mmol) of trans-
1
1
,2-dichlorocyclopentane, 4.40 g (33.3 mmol) of PhSNa, and
0 mL of ethylene glycol. The tube was heated and periodically
cooled and opened for GC assay on column A. On this column,
- and 3-(phenylthio)cyclopentene could not be distinguished
1
Su p p or tin g In for m a tion Ava ila ble: Figures F1-F8
Ortep diagrams) and tables giving X-ray crystallographic data
and were assayed together. After 19 h at 110 °C followed by 4
d at 140 °C, the solution contained 4% of dichlorocyclopentane,
(
for 9a , 4b, 15a , 17a , 18, 21, 22, and 8a . This information is
available free of charge via the Internet at http://pubs.acs.org.
2
9% of (phenylthio)cyclopentenes, and 67% of trans-1,2-di-
(phenylthio)cyclopentane. The solution was poured into 60 mL
J O0104633
(
(
14) Neumann, H.; Seebach, D. Chem. Ber. 1978, 111, 2785-2805.
15) Trost, B. M.; Lavoie, A. C. J . Am. Chem. Soc. 1983, 105, 5075-
(16) Mousseron, M. Bull. Soc. Chim. Fr. (M) 1948, 84-90.
(17) Sheldrick, G. Bruker AXS, 1997, Madison, WI.
5
090.