Ruthenium-catalyzed reaction of alkenyl triflates with zinc thiolates

Article abstract of DOI:10.1016/j.tet.2011.09.145

A ruthenium complex coordinated with 3,4,7,8-tetramethyl-1,10- phenanthroline catalyzed the reaction of alkenyl triflates with zinc dithiolates to give alkenyl sulfides.

Full text of DOI:10.1016/j.tet.2011.09.145

Tetrahedron 67 (2011) 10212e10215
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Ruthenium-catalyzed reaction of alkenyl triflates with zinc thiolates
*
*
Yusuke Imazaki, Eiji Shirakawa , Tamio Hayashi
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
A ruthenium complex coordinated with 3,4,7,8-tetramethyl-1,10-phenanthroline catalyzed the reaction
of alkenyl triflates with zinc dithiolates to give alkenyl sulfides.
Ó 2011 Elsevier Ltd. All rights reserved.
Received 6 September 2011
Received in revised form 30 September 2011
Accepted 30 September 2011
Available online 6 October 2011
Keywords:
Ruthenium catalyst
Alkenyl triflates
Thiolation
Alkenyl sulfides
Zinc thiolates
1. Introduction
2. Results and discussion
During the past few decades, a wide variety of ruthenium-
catalyzed reactions, such as hydrogenation, oxidation, olefin me-
tathesis, and CeH bond functionalization have been developed.1
Most of these reactions involve transformation of CeC un-
saturated bonds and/or CeH bonds. In contrast, activation of
C(sp2)eX bonds in aryl and alkenyl halides under ruthenium ca-
talysis is much less common than that under palladium or nickel
catalysis.2 The pioneering work on catalytic activation of C(sp2)eX
A ruthenium complex coordinated with 3,4,7,8-tetramethyl-
1,10-phenanthroline (Me4-phen) was found to catalyze the thio-
lation of alkenyl triflates. Thus, in the presence of a ruthenium
complex prepared from Ru(acac)3 (3 mol %) and Me4-phen (3 mol %),
1-cyclohexenyl triflate (1a: 1 equiv) was treated with NaSPh (2m:
1.2 equiv) in 1,3-dimethyl-2-imidazolidinone (DMI) at 120 ꢀC for
24 h11 to give 46% yield of 1-cyclohexenyl phenyl sulfide (3am)
(entry 1 of Table 1). Use of PhSSPh (4m: 1.2 equiv) as a phenylthio
source in combination with zinc powder (1.35 equiv) improved the
yield to 78% (entry 2). A 1:1 mixture of Zn and 4m is known to be
transformed to Zn(SPh)2,12 which is likely to react with the ruthe-
nium complex. Only a trace amount of 3am was obtained by use of
Zn(SPh)2 prepared beforehand in a manner that zinc metal does not
remain (entry 3), showing that the active species is a low valent
ruthenium complex generated by reduction of Ru(acac)3 by zinc.13
Use of [RuCl2(p-cymene)]2 instead of Ru(acac)3 gave 3am in
a higher yield (entry 4). Use of a reduced amount (1.0 equiv) of 4m
gave a comparable yield of 3am (entry 5). Thioether 3am was ob-
tained in an amount larger than that of 4m used (entry 6), showing
that both of the two thiolate moieties of Zn(SPh)2 have potential
ability to participate in the thiolation. In order to restore the nu-
cleophilicity of the PhS moiety diminished upon transformation to
PhSZnOTf through the first transferof PhS, NaOAc was added to form
more nucleophilic PhSZnOAc and the yield was increased to 81%
even in use of 0.6 equiv of 4m (entry 7). Phenylthiol also was used as
a phenylthio source in combination with Et2Zn (entry 8). Non-
substituted 1,10-phenanthroline (phen) and 2,20-bipyridyl (bpy)
bonds by a ruthenium complex is the coupling reaction of b-bro-
mostyrene with Grignard reagents or organolithium compounds
reported by Murahashi and co-workers in 1979.3 After a long while,
the coupling reaction of aryl or alkenyl (pseudo)halides with arenes
bearing a directing group was extensively studied.4 Only a few re-
ports are available for other types of substitution reactions, such as
the MizorokieHeck reaction, SuzukieMiyaura coupling, and Sono-
gashira coupling reactions.5 On the other hand, we have recently
reported the ruthenium-catalyzed transformation of alkenyl tri-
flates to alkenyl halides using lithium halides as the first example on
the ruthenium-catalyzed reaction of aryl or alkenyl (pseudo)halides
with heteroatom nucleophiles.6,7 Here we report the ruthenium-
catalyzed reaction of alkenyl triflates or halides with zinc thiolates
to give alkenyl sulfides,8 which are important moieties of synthetic
precursors9 and biologically active compounds.10
* Corresponding authors. Tel.: þ81 75 753 3985; fax: þ81 75 753 3988; e-mail
address: shirakawa@kuchem.kyoto-u.ac.jp (E. Shirakawa).
0040-4020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.09.145

Y. Imazaki et al. / Tetrahedron 67 (2011) 10212e10215
10213
Table 1
Ruthenium-catalyzed phenylthiolation of 1-cyclohexenyl triflatea
Table 2
Ruthenium-catalyzed thiolation of alkenyl electrophiles with zinc thiolatesa
Entry
Ligand
(mol %)
Phenylthio source and
other reagents (equiv)
Yieldb
(%)
1c
2c
3c,d
4
5
6
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
NaSPh (2m: 1.2)
46
78
4
94
93
68
81
Entry
1
1
R4
Yieldb (%)
93
Product
PhSSPh (4m: 1.2), Zn (1.35)
PhSSPh (4m: 1.2), Zn (1.0)
PhSSPh (4m: 1.2), Zn (1.35)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 0.6), Zn (0.75)
PhSSPh (4m: 0.6), Zn (0.75),
NaOAc (1.2)
Ph (4m)
3am
1a
7
2
1a
1a
1a
1a
1a
4-MeOC6H4 (4n)
4-BrC6H4 (4o)
Bu (4p)
95
77
68
85
0
3an
3ao
3ap
3aq
3ar
3c,d
4
8
9
Me4-phen (3)
phen (3)
bpy (3)
PPh3 (6)
dppp (3)
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
Me4-phen (3)
PhSH (2.0), Et2Zn (1.1)
87
58
58
7
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
PhSSPh (4m: 1.0), Zn (1.15)
5
6
Cyclohexyl (4q)
10
11
12
13e
14f
15g
16h
tBu (4r)
5
86
53
1
7
Ph (4m)
83
3bm
1b
1c
23
8c
Ph (4m)
Ph (4m)
78
89
3cm
3dm
a
The reaction was carried out in DMI (1.0 mL) at 120 ꢀC for 24 h under a nitrogen
atmosphere using 1-cyclohexenyl triflate (1a: 0.25 mmol), a phenylthio source and
other reagents in the presence of [RuCl2(p-cymene)]2 (3.8
m
mol) and a ligand.
9d
b
Determined by GC.
Ru(acac)3 (7.5
1d
c
m
mol) was used instead of [RuCl2(p-cymene)]2.
PhSSPh and Zn was stirred at 120 ꢀC for 24 h in DMI before addition of Ru(acac)3
and 1a.
d
80
10c,d
Ph (4m)
Ph (4m)
3em
3fm
e
1e
(3em/3fm¼98:2)
NMP was used as a solvent.
DMF was used as a solvent.
DMSO was used as a solvent.
1,4-Dioxane was used as a solvent.
f
(1e/1f = 95:5)
g
h
69
11c,e
(3fm/3em¼93:7)
1f
(1f/1e = 94:6)
were less effective as ligands than Me4-phen, and only a trace
amount of 3am was obtained by use of a phosphine ligand (entries
9e12). N-Methylpyrrolidone (NMP) also was effective as a solvent,
whereas the reaction was sluggish in DMF, DMSO, or 1,4-dioxane
(entries 13e16).
12d
13
Ph (4m)
Ph (4m)
71g
3gm
3hm
f
1g
82
Various alkenyl triflates and iodides were thiolated under the
reaction conditions of entry 5 of Table 1. In addition to diphenyl
disulfide (4m), methoxy- or bromo-substituted ones reacted with
1-cyclohexenyl triflate (1a) in high yields (entries 1e3 of Table 2).
The reaction of primary and secondary alkyl disulfides gave the
corresponding alkyl sulfides, whereas no thiolation took place with
tBuSStBu (4r) (entries 4e6). The thiolation reaction is applicable to
various cyclic alkenyl triflates (entries 7e11), which have advan-
tages over cyclic alkenyl halides in facility of preparation, in par-
ticular in regioselective synthesis from unsymmetrical ketones.14
For example, methylcyclohexenyl trifltates 1e and 1f were pre-
pared regioselectively from the same ketone, and were converted
to the corresponding alkenyl sulfides without migration of the
double bond (entries 10 and 11).8b For trisubstituted alkenyl triflate
1f, 4,7-dimethoxy-1,10-phenanthroline [(MeO)2-phen] as a ligand
was effective. The reaction of acyclic alkenyl triflates and iodides
took place in high yields (entries 12e15). Although 1-octen-2-yl
triflate was unstable under the reaction conditions,15 the corre-
sponding iodide (1g) underwent the coupling without de-
composition (entry 12). Both E- and Z-isomers of 1-octen-1-yl
iodide (1i) reacted with 4m to give a mixture of stereoisomers of
the same E/Z ratio (entries 14 and 15).
(E/Z¼86:14)
1h (E/Z = 97:3)
84
14c,h
Ph (4m)
Ph (4m)
3im
3im
(E/Z¼92:8)
1i (E/Z = 100:0)
1i (E/Z = 3:97)
77
15c,h
(E/Z¼92:8)
a
The reaction was carried out in DMI (1.0 mL) at 120 ꢀC for 24 h under a nitrogen
atmosphere using an alkenyl triflate (1: 0.25 mmol), a disulfide (4: 0.25 mmol), and
zinc powder (0.29 mg atom) in the presence of [RuCl2(p-cymene)]2 (3.8
Me4-phen (7.5 mol).
mmol) and
m
b
Isolated yield.
The reaction was carried out for 48 h.
c
d
[RuCl2(p-cymene)]2 (7.5 mmol), Me4-phen (15 mmol), and Zn (0.30 mg atom)
were used.
e
The reaction was carried out at 140 ꢀC using [RuCl2(p-cymene)]2 (12.5
(MeO)2-phen (25 mol), and Zn (0.31 mg atom).
mmol),
m
f
Containing 13% of 2-iodo-2-octene.
g
Containing 7% of 2-octen-2-yl phenyl sulfide.
[RuCl2(p-cymene)]2 (7.5 mmol), (MeO)2-phen (15
h
m
mol), and Zn (0.30 mg atom)
were used.
configurationally stable. These results show that the isomerization
takes place during transformation from alkenyl (pseudo)halides to
sulfides, suggesting that the ruthenium-catalyzed thiolation pro-
ceeds through a different mechanism from that of palladium-
catalyzed one, which consists of oxidative addition, trans-
metalation, and reductive elimination and thus proceeds with re-
tention of stereochemistry.8e
To clarify when the E/Z isomerization takes place, stereochem-
ical stabilities of an alkenyl triflate and the corresponding alkenyl
sulfide were examined (Scheme 1). Analysis of a reaction mixture at
the middle stage showed that the E/Z ratio of the starting alkenyl
iodide (1i) was conserved during the thiolation. Under the condi-
tions where thiolation of 1h proceeds, alkenyl sulfide 3im was

10214
Y. Imazaki et al. / Tetrahedron 67 (2011) 10212e10215
on a JEOL JNM LA500 (1H, 500 MHz; 13C, 125 MHz) spectrometer.
High-resolution mass spectra (APCI) were obtained with a Bruker
Daltonics microTOF-Q spectrometer. Unless otherwise noted, re-
agents were commercially available and used without further pu-
rification.1,3-Dimethyl-2-imidazolidinone (DMI) was distilled from
CaH2. Alkenyl triflates and iodides were prepared according to the
literature procedures.14,16
3.2. General procedure for ruthenium-catalyzed reaction of
alkenyl electrophiles with zinc thiolates (Table 2)
To
a
mixture of [RuCl2(p-cymene)]2 (2.3 mg, 3.8
mmol),
3,4,7,8-tetramethyl-1,10-phenanthroline (1.8 mg, 7.5
mmol), zinc pow-
der (18.8 mg, 0.288 mg atom), a disulfide(0.25 mmol), and DMI(1.0 mL)
placed in a flame-dried 20 mL Schlenk tube was added an alkenyl
electrophile (0.25 mmol). After stirring at 120 ꢀC for 24 h, the reaction
mixture was extracted with diethyl ether (3ꢁ10 mL). The combined
organic layer was washed with water (2ꢁ15 mL) and brine (15 mL), and
dried over MgSO4. After filtration and evaporation, the crude product
was subjected to column chromatography on silica gel (hexane/NEt3
97:3) or alumina (hexane) to give the corresponding product.
Scheme 1.
3.2.1. 1-Cyclohexenyl phenyl sulfide (3am)8b. A colorless oil.1H NMR
(500 MHz, CDCl3) d 1.58e1.72 (m, 4H), 2.12e2.20 (m, 4H), 6.06e6.10
(m, 1H), 7.19 (t, J¼7.1 Hz, 1H), 7.26e7.34 (m, 4H). 13C NMR (125 MHz,
In a competition reaction, alkenyl triflate 1h was much more
reactive than alkenyl iodide 1i under the ruthenium catalysis
(Scheme 2). Thus, 43% of 1h and 14% of 1i were consumed in the
presence of [RuCl2(p-cymene)]2 (6 mol % Ru) and Me4-phen
(6 mol %) in DMI at 120 ꢀC for 30 min to give 33% of 3hm and 5% of
3im. In contrast, iodide 1i showed fourfold reactivity compared
with triflate 1h in the presence of Pd(PPh3)4 (3 mol %). The opposite
reactivity order also may be ascribed to the different mechanism.
Although the reaction mechanism is unclear at present, the
ruthenium-catalyzed reaction possibly proceeds via alkenyl radical
or cation intermediates in a similar manner to the ruthenium-
catalyzed transformation of alkenyl triflates to alkenyl halides.6
CDCl3) d 21.8, 23.8, 26.9, 30.2, 126.4, 129.0, 130.3, 131.6, 132.9, 135.4.
3.2.2. 1-Cyclohexenyl 4-methoxyphenyl sulfide (3an). A colorless oil.
1H NMR (500 MHz, CDCl3)
1.55e1.68 (m, 4H), 2.06e2.13 (m, 4H),
d
3.80 (s, 3H), 5.77e5.82 (m, 1H), 6.85 (d, J¼8.9 Hz, 2H), 7.32 (d,
J¼8.9 Hz, 2H). 13C NMR (125 MHz, CDCl3)
d 22.0, 23.7, 26.7, 29.7,
55.4, 114.7, 124.7, 128.0, 133.5, 134.2, 159.3. HRMS (APCI) calcd for
C13H17OS: [MþH]þ 221.0995. Found m/z 221.1001.
3.2.3. 4-Bromophenyl 1-cyclohexenyl sulfide (3ao). A colorless oil.
1H NMR (500 MHz, CDCl3)
d 1.58e1.72 (m, 4H), 2.08e2.20 (m, 4H),
6.09e6.13 (m, 1H), 7.16 (d, J¼8.6 Hz, 2H), 7.39 (d, J¼8.6 Hz, 2H). 13C
NMR (125 MHz, CDCl3)
d 21.7, 23.8, 27.0, 30.1, 120.3, 131.0, 131.6,
132.1,134.1, 134.9. HRMS (APCI) calcd for C12H13BrS: [M]þ, 267.9916.
Found m/z 267.9913.
3.2.4. Butyl 1-cyclohexenyl sulfide (3ap). A colorless oil. H NMR
(500 MHz, CDCl3)
d
0.92 (t, J¼7.4 Hz, 3H), 1.42 (sext, J¼7.3 Hz, 2H),
1.52e1.63 (m, 4H), 1.65e1.72 (m, 2H), 2.05e2.17 (m, 4H), 2.65 (t,
J¼7.4 Hz, 2H), 5.59e5.64 (m, 1H). 13C NMR (125 MHz, CDCl3)
d 13.8,
22.2, 22.3, 23.5, 26.5, 30.1, 30.6, 31.4, 123.1,132.3. HRMS (APCI) calcd
for C10H19S: [MþH]þ, 171.1202. Found m/z 171.1208.
3.2.5. 1-Cyclohexenyl cyclohexyl sulfide (3aq)8b. A colorless oil. 1H
NMR (500 MHz, CDCl3) d1.18e1.36 (m, 5H), 1.55e1.63 (m, 3H),
1.65e1.71 (m, 2H), 1.72e1.81 (m, 2H), 1.89e1.98 (m, 2H), 2.07e2.12
(m, 2H), 2.13e2.18 (m, 2H), 2.89e2.98 (m, 1H), 5.78e5.82 (m, 1H).
13C NMR (125 MHz, CDCl3)
42.8, 127.8, 131.3.
d 22.1, 23.7, 26.0, 26.2, 26.7, 30.9, 33.6,
Scheme 2.
In conclusion, we have described the reaction of alkenyl triflates
with zinc thiolates as a new entry of ruthenium-catalyzed reaction
of sp2-carbon electrophiles.
3.2.6. 1-Cycloheptenyl phenyl sulfide (3bm). A colorless oil. 1H NMR
(500 MHz, CDCl3) 1.50e1.58 (m, 4H), 1.72e1.77 (m, 2H), 2.17e2.23
(m, 2H), 2.32e2.38 (m, 2H), 6.16 (t, J¼6.6 Hz, 1H), 7.20 (t, J¼7.0 Hz,
1H), 7.26e7.35 (m, 4H). 13C NMR (125 MHz, CDCl3)
26.9, 27.2, 29.5,
d
d
3. Experimental section
3.1. General
32.1, 35.5, 126.5, 129.0, 130.6, 135.8, 135.9, 137.4. HRMS (APCI) calcd
for C13H17S: [MþH]þ, 205.1045. Found m/z 205.1047.
3.2.7. 1-Cyclopentenyl phenyl sulfide (3cm). A colorless oil. Contains
All manipulations of oxygen- and moisture-sensitive materials
were conducted with a standard Schlenk technique under a nitro-
gen atmosphere. Nuclear magnetic resonance spectra were taken
2% of PhSSPh. 1H NMR (500 MHz, CDCl3)
d
1.97 (quint, J¼7.5 Hz, 2H),
2.37e2.45 (m, 4H), 5.71e5.75 (m, 1H), 7.24 (t, J¼7.5 Hz, 1H), 7.31 (t,
J¼7.7 Hz, 2H), 7.39 (d, J¼7.2 Hz, 2H). 13C NMR (125 MHz, CDCl3)

Y. Imazaki et al. / Tetrahedron 67 (2011) 10212e10215
10215
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University Science Books: Sausalito, 2010, pp 877e965.
3. Murahashi, S.-I.; Yamamura, M.; Yanagisawa, K.-I.; Mita, N.; Kondo, K. J. Org.
d
23.9, 33.1, 35.9, 127.1, 129.0, 131.4, 131.5, 134.4, 135.9. HRMS (APCI)
calcd for C11H13S: [MþH]þ, 177.0732. Found m/z 177.0729.
Chem. 1979, 44, 2408e2417.
3.2.8. 1,2-Dihydro-3-(phenylthio)naphthalene (3dm)17. A colorless
4. (a) Oi, S.; Fukita, S.; Hirata, N.; Watanuki, N.; Miyano, S.; Inoue, Y. Org. Lett.
2001, 3, 2579e2581; (b) A recent review of direct arylation, see: Acker-
mann, L.; Vicente, R.; Kapdi, A. R. Angew. Chem., Int. Ed. 2009, 48,
9792e9826.
5. (a) Mitsudo, T.; Takagi, M.; Zhang, S.-W.; Watanabe, Y. J. Organomet. Chem.
1992, 423, 405e414; (b) Na, Y.; Park, S.; Han, S. B.; Han, H.; Ko, S.; Chang, S.
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1050e1051.
6. Shirakawa, E.; Imazaki, Y.; Hayashi, T. Chem. Commun. 2009, 5088e5090.
7. Ruthenium-catalyzed SNAr reaction of aryl fluorides with amines has recently
been reported: (a) Otsuka, M.; Endo, K.; Shibata, T. Chem. Commun. 2010,
336e338; (b) Otsuka, M.; Yokoyama, H.; Endo, K.; Shibata, T. Synlett 2010,
2601e2606.
8. Palladium-catalyzed reaction of alkenyl electrophiles with thiolates, see: (a)
Carpita, A.; Rossi, R.; Scamuzzi, B. Tetrahedron Lett. 1989, 30, 2699e2702; (b)
García Martínez, A.; Osío Barcina, J.; de Fresno Cerezo, A.; Subramanian, L. R.
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Eichman, C. C.; Stambuli, J. P. J. Org. Chem. 2009, 74, 4005e4008; (e) Mecha-
nistic studies on palladium-catalyzed reaction of alkenyl halides with a thiol in
the presence of a base, see: Moreau, X.; Campagne, J. M.; Meyer, G.; Jutand, A.
Eur. J. Org. Chem. 2005, 3749e3760; (f) Nickel-catalyzed reaction of alkenyl
electrophiles with thiolates, see: Crisau, H. J.; Chabaud, B.; Labaudiniere, R.;
Christol, H. J. Org. Chem. 1986, 51, 875e878; (g) Yatsumonji, Y.; Okada, O.;
Tsubouchi, A.; Takeda, T. Tetrahedron 2006, 62, 9981e9987; (h) Copper-cata-
lyzed reaction of alkenyl electrophiles with thiolates, see: Bates, C. G.; Saejueng,
P.; Doherty, M. Q.; Venkataraman, D. Org. Lett. 2004, 6, 5005e5008; (i) Manarin,
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Kabir, M. S.; Van Linn, M. L.; Monte, A.; Cook, J. M. Org. Lett. 2008, 10,
3363e3366.
oil. 1H NMR (500 MHz, CDCl3)
d
2.45 (t, J¼8.0 Hz, 2H), 2.87 (t,
J¼8.0 Hz, 2H), 6.49 (s, 1H), 6.95 (d, J¼7.0 Hz, 1H), 7.08e7.16 (m, 3H),
7.28e7.33 (t, J¼7.3 Hz, 1H), 7.36 (t, J¼7.5 Hz, 2H), 7.49 (d, J¼8.0 Hz,
2H). 13C NMR (125 MHz, CDCl3)
d 29.0, 29.1, 125.8, 126.8, 127.10,
127.13, 127.5, 127.7, 129.3, 132.3, 133.6, 134.2, 134.4, 136.2.
3.2.9. 6-Methyl-1-cyclohexenyl phenyl sulfide (3em)8b. A colorless
oil. Contains 2% of regioisomer (3fm). 1H NMR (500 MHz, CDCl3)
d
1.14 (d, J¼7.1 Hz, 3H), 1.50e1.83 (m, 4H), 2.09e2.23 (m, 2H),
2.26e2.30 (m, 1H), 6.06 (t, J¼3.8 Hz, 1H), 7.19 (t, J¼7.2 Hz, 1H), 7.29
(t, J¼7.4 Hz, 2H), 7.33 (d, J¼7.2 Hz, 2H). 13C NMR (125 MHz, CDCl3)
d
18.5, 20.2, 27.3, 31.4, 32.9, 126.2, 129.0, 130.1, 134.0, 136.2, 137.1.
3.2.10. 2-Methyl-1-cyclohexenyl phenyl sulfide (3fm)8b. A colorless
oil. Contains 7% of regioisomer (3em). 1H NMR (500 MHz, CDCl3)
d
1.60e1.71 (m, 4H), 1.96 (s, 3H), 2.12e2.24 (m, 4H), 7.13 (t, J¼7.2 Hz,
1H), 7.20 (d, J¼8.3 Hz, 2H), 7.25 (t, J¼7.6 Hz, 2H). 13C NMR (125 MHz,
CDCl3)d21.9, 23.0, 24.4, 32.1, 33.1,123.3,125.3,128.2,128.9,137.0,141.9.
3.2.11. 1-Octen-2-yl phenyl sulfide (3gm). A colorless oil. Contains
9% of 2-octen-2-yl phenyl sulfides. 1H NMR (500 MHz, CDCl3)
0.89
d
(t, J¼7.0 Hz, 3H), 1.20e1.34 (m, 6H), 1.50e1.59 (m, 2H), 2.22 (t,
J¼7.6 Hz, 2H), 4.87 (s, 1H), 5.14 (s, 1H), 7.28 (t, J¼7.3 Hz, 1H), 7.33 (t,
9. (a) Trost, B. M.; Lavoie, A. C. J. Am. Chem. Soc. 1983, 105, 5075e5090; (b) De
Lucchi, O.; Pasquato, L. Tetrahedron 1988, 44, 6755e6794; (c) Mizuno, H.;
Domon, K.; Masuya, K.; Tanino, K.; Kuwajima, I. J. Org. Chem. 1999, 64,
2648e2656.
10. (a) Marcantoni, E.; Massaccesi, M.; Petrini, M. J. Org. Chem. 2000, 65,
4553e4559; (b) Johannesson, P.; Lindeberg, G.; Johansson, A.; Nikiforovich, G.
J¼7.2 Hz, 2H), 7.44 (d, J¼8.2 Hz, 2H).13C NMR (125 MHz, CDCl3)
d 14.2,
22.7, 28.5, 28.7, 31.7, 36.7,112.6,127.8,129.2,133.4,133.5,146.3. HRMS
(APCI) calcd for C14H21S: [MþH]þ, 221.1358. Found m/z 221.1352.
3.2.12. 1-Nonen-1-yl phenyl sulfide (3hm). A colorless oil. E/Z¼87/
13. The italicized peaks could not be assigned to each isomer. The
peaks in 13C NMR were characterized by a comparison of 13C NMR
spectra between a mixture of stereoisomers in 87/13 (E/Z) ratio and
that in 52/48 ratio, which was obtained through isomerization on
ꢀ
ꢁ
V.; Gogoll, A.; Synnergren, B.; Le Greves, M.; Nyberg, F.; Karlen, A.; Hallberg, A. J.
Med. Chem. 2002, 45, 1767e1777; (c) Sader, H. S.; Johnson, D. M.; Jones, R. N.
Antimicrob. Agents Chemother. 2004, 48, 53e62.
11. The most effective catalyst system (3 mol % of Ru(acac)3, 3 mol % of Me4-phen,
120 ꢀC, 24 h) for the transformation of alkenyl triflates to alkenyl halides was
first employed.
12. Transition metal-catalyzed reaction of aryl electrophiles with PhSSPh and zinc,
see: (a) Taniguchi, N. J. Org. Chem. 2004, 69, 6904e6906; (b) Fukuzawa, S.;
Tanihara, D.; Kikuchi, S. Synlett 2006, 2145e2147.
13. Ruthenium(III) complexes are known to be reduced by Zn to ruthenium(0)
complexes. (a) Pertici, P.; Vitulli, G.; Porri, L. J. Chem. Soc., Chem. Commun. 1975,
846; (b) Hill, A. F.; Neumann, H.; Wagler, J. Organometallics 2010, 29,
1026e1031; (c) For reduction of [RuCl2(p-cymene)]2 by Zn to a ruthenium(0)
complex, see: Bates, R. S.; Wright, A. H. J. Chem. Soc., Chem. Commun. 1990,
1129e1131. The reaction of 1a with NaSPh (2m) shown in entry 1 proceeded
even in the absence of Zn, probably because NaSPh, which should be more
nucleophilic than Zn(SPh)2, can reduce Ru(acac)3 to a catalytically active Ru(0)
complex.
silica gel. 1H NMR (500 MHz, CDCl3)
d
0.90 (t, J¼6.9 Hz, 3H),
1.24e1.37 (m, 8H), 1.38e1.48 (m, 2H), 2.17/2.26 (q, J¼7.0/7.4 Hz, 2H),
6.00/5.83 (dt, J¼15.0, 7.0/9.3, 7.4 Hz, 1H), 6.14/6.19 (d, J¼15.0/9.3 Hz,
1H), 7.18 (t, J¼6.9 Hz, 1H), 7.26e7.36 (m, 4H). 13C NMR (125 MHz,
CDCl3) E-3hm:
d 14.2, 22.8, 29.16, 29.21, 29.24, 31.97, 33.2, 120.8,
126.1, 128.5, 129.0, 136.9, 138.0. Z-3hm:
d 14.2, 22.8, 29.19, 29.28,
29.34, 31.99, 33.2, 122.8, 126.2, 128.9, 129.1, 133.9, 136.7. HRMS
(APCI) calcd for C15H23S: [MþH]þ, 235.1515. Found m/z 235.1519.
3.2.13. 1-Octen-1-yl phenyl sulfide (3im)16b. A colorless oil. E/Z¼92/
14. (a) Ritter, K. Synthesis 1993, 735e762; (b) Baraznenok, I. L.; Nenajdenko, V. G.;
Balenkova, E. S. Tetrahedron 2000, 56, 3077e3119.
8. The italicized peaks could not be assigned to each isomer. 1H
15. Treatment of 1-octen-2-yl triflate under the reaction conditions but in the
absence of a ruthenium catalyst gave an isomeric mixture of octenyl phenyl
sulfides. The thiolation is likely to proceed via addition of thiolates to alkynes
generated by elimination reaction because 1- and 2-octynes were observed at
the early stage of the reaction.
NMR (500 MHz, CDCl3)
d
0.90 (t, J¼6.8 Hz, 3H), 1.24e1.33 (m, 6H),
1.34e1.47 (m, 2H), 2.17/2.25 (q, J¼7.2/6.6 Hz, 2H), 6.00/5.83 (dt,
J¼15.0, 7.0/9.2, 7.3 Hz, 1H), 6.14/6.19 (d, J¼15.0/9.2 Hz, 1H), 7.18 (t,
J¼6.9 Hz, 1H), 7.26e7.36 (m, 4H).
16. For synthesis of alkenyl iodide 1g: (a) Kamiya, N.; Chikami, Y.; Ishii, Y.
Synlett 1990, 675e676 (E)-1i: (b) Ren, H.; Krasovskiy, A.; Knochel, P. Org.
Lett. 2004, 6, 4215e4217 (Z)-1i: (c) Brown, H. C.; Hamaoka, T.; Ravindran, N.;
Subrahmanyam, C.; Somayaji, V.; Bhat, N. G. J. Org. Chem. 1989, 54,
6075e6079.
References and notes
€
17. Muller, P.; Bernardinelli, G.; Godoy-Nguyen Thi, H. C. Helv. Chim. Acta 1989, 72,
1. Ruthenium in Organic Synthesis; Murahashi, S.-I., Ed.; Wiley-VCH: Weinheim,
1627e1638.
2004.