Regio- and stereoselective additions of diphenyldithiophosphinic acid to N-(1-alkynyl)amides and 1-alkynyl sulfides

Article abstract of DOI:10.1246/bcsj.81.506

Treatment of N-(l-alkynyl)amides and 1-alkynyl sulfides with diphenyldithiophosphinic acid affords (E)-ketene N,S-acetals and S.S-acetals, respectively. The addition reactions proceed in syn fashions, which consist of protonation of the electron-rich alkynes and the following nucleophilic addition of diphenyldithiophosphinate anion to the resulting cationic intermediates.

Full text of DOI:10.1246/bcsj.81.506

506 Bull. Chem. Soc. Jpn. Vol. 81, No. 4, 506–514 (2008)
ꢀ 2008 The Chemical Society of Japan
Regio- and Stereoselective Additions of Diphenyldithiophosphinic
Acid to N-(1-Alkynyl)amides and 1-Alkynyl Sulfides
ꢀ
ꢀ
Shigenari Kanemura, Azusa Kondoh, Hiroto Yasui, Hideki Yorimitsu, and Koichiro Oshima
Department of Material Chemistry, Graduate School of Engineering, Kyoto University,
Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510
Received December 12, 2007; E-mail: yori@orgrxn.mbox.media.kyoto-u.ac.jp
Treatment of N-(1-alkynyl)amides and 1-alkynyl sulfides with diphenyldithiophosphinic acid affords (E)-ketene
N,S-acetals and S,S-acetals, respectively. The addition reactions proceed in syn fashions, which consist of protonation
of the electron-rich alkynes and the following nucleophilic addition of diphenyldithiophosphinate anion to the resulting
cationic intermediates.
Addition of a hydrogen–sulfur bond across a carbon–carbon
triple bond, hydrothiolation of alkyne, is useful for the syn-
thesis of 1-alkenyl sulfide.1 Hydrothiolation of alkyne under
acidic conditions is interesting because of the characteristic
Markovnikov regioselectivity. Here, we report hydrothiolation
reactions of electron-rich alkynes, N-(1-alkynyl)amides2,3 and
1-alkynyl sulfides,4,5 with diphenyldithiophosphinic acid. The
reactions under acidic conditions afford ketene N,S-acetals
(=1-amino-1-thio-1-alkenes) and S,S-acetals (1,1-dithio-1-al-
kenes), which are useful building blocks for organic synthesis.6
Table 1. Hydrothiolation Reactions of Ynamides 1 with
Diphenyldithiophosphinic Acid (2)
S
P
HS
Ph
S
Ph
2
SO2Ar
R2
S PPh2
(1.2 mol. amt.)
R1 C C N
DME, 25 °C, 1 h
R1
N SO2Ar
1
R2
3
Entry
1
R1
R2
Ar
3
Yield/%a)
Results and Discussion
1
2
3
4
5
6
7
8
9
1a Ph
1b Me
1c p-MeC6H4 Me
1d o-MeC6H4 Me
1e p-ClC6H4 Me
1f p-AcC6H4 Me
1g Me3Si
1h
1i Ph
Me
Me
p-MeC6H4 3a 87 (98)b)
p-MeC6H4 3b 76
p-MeC6H4 3c 91
p-MeC6H4 3d 97
p-MeC6H4 3e 88
p-MeC6H4 3f 97
p-MeC6H4 3g 63c)
p-MeC6H4 3h 86
Addition to N-(1-Alkynyl)amides.7 N-Phenylethynyl-N-
methyl-p-toluenesulfonamide (1a) was treated with diphenyl-
dithiophosphinic acid (2) in 1,2-dimethoxyethane (DME) at
room temperature for 1 h to provide (E)-1-[methyl(p-tolylsul-
fonyl)amino]-2-phenylethenyl diphenyldithiophosphinate (3a)
in 87% yield as the sole product (Table 1, Entry 1). The reac-
tion proceeded in a syn fashion with perfect regio- and stereo-
selectivity.8 A variety of ynamides underwent the hydrothiola-
tion. The reaction of N-1-propynylamide 1b yielded 3b in
good yield (Entry 2). The stereochemistry of the reaction
was confirmed by analyzing nuclear Overhauser effect. Irradi-
ation of the methyl group on the nitrogen of 3b enhanced the
intensity of the signal for the methyl group of the propenyl
moiety (12%). The steric as well as electronic factors of the
aryl groups attached to the carbon–carbon triple bonds were
moderate (Entries 3–6). The reactions of trimethylsilyl-sub-
stituted ynamide 1g and terminal alkyne 1h also furnished
the desired products 3g and 3h (Entries 7 and 8). Not only
p-toluenesulfonamides but also p-nitrobenzenesulfonamide 1j
reacted with 2 smoothly to afford the corresponding product
3j in 97% isolated yield (Entry 10). The choice of the solvent
is not an important factor. For instance, the reaction of 1a with
2 proceeded in DME, ethanol, dichloromethane, and hexane
to afford 3a in 98%, 97%, 91%, and 95% NMR yields,
respectively.
Me
Me
H
CH2=CHCH2 p-MeC6H4 3i 95
Me p-NO2C6H4 3j 97
10 1j Ph
a) Isolated yields by silica gel column chromatography unless
otherwise specified. b) NMR yield based on 31P NMR analysis.
c) Isolated yield after recrystallization.
S
P
Ts
+
D C C N
HS
Ph
DME, 25 °C, 1 h
Me
Ph
2
1h-d (> 99%D)
(1.2 mol. amt.)
S
S
S
H
H
S PPh2
S PPh2
N Ts
D
D
S PPh2
+
+
N Ts
D
N Ts
Me
3h
Me
Me
3h-d2
3h-d (E/Z = 1:1)
The reaction of deuterium-labeled ynamide 1h-d yielded a
mixture of adducts 3h, 3h-d, and 3h-d2 in 93% combined yield
in a ratio of 18:75:7 (Scheme 1). Monodeuterated 3h-d was
93% (3h/3h-d/3h-d2 = 18:75:7)
Scheme 1. Reaction of deuterated ynamide.
Published on the web April 10, 2008; doi:10.1246/bcsj.81.506

S. Kanemura et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
507
respectively, in high yield (eq 1). Diphenyldithiophosphinic
acid (2) would be generated in situ under the reaction condi-
tions. It was reported that reaction of Ph2PH and 2 molar
amount of sulfur in refluxing benzene afforded Ph2P(=S)SH.9
Catalytic amounts of butyllithium would accelerate the forma-
tion of Ph2P(=S)SH by generating Ph2PLi in situ. Indeed,
treatment of diphenylphosphine with a catalytic amount of
butyllithium in the presence of sulfur in DME at 25 ꢂC for
1 h afforded diphenyldithiophosphinic acid (2) in 56% NMR
yield (31P NMR: ꢀ 53.78 in CDCl3), after acid–base extraction.
S
P
−
Ph
Ph
2−
2
S
2−
H
+
N
Ts
1h-d
3h-d
C
C
Me
D
2−
4h-d
2
2−
1h-d
S
P
Ph
Ph
nBuLi (0.1 mol. amt.)
HPPh2 (1.5 mol. amt.)
DS
Ts
2
S
2-d
C
H C
N
3h
Ts
S PPh2
S (3.0 mol. amt.)
Me
C
R C
N
Me
3h-d2
1h
ð1Þ
DME, 25 °C
R
N Ts
Scheme 2. Plausible reaction mechanism for hydrothiolation.
R = Ph (1a)
R = Me (1b)
Me
R = Ph (3a) : 92% (2 h)
R = Me (3b) : 78% (1 h)
Transformation of the ketene N,S-acetals 3 was investigated
to show the utility of 3. The reaction of 3a with 4.0 molar
amount of t-butyllithium in ether at 0 ꢂC provided thioimidate
5 in high yield (Scheme 3).10 Attack of the sulfur atom attach-
ed to the olefinic carbon of 3a by t-butyllithium could afford
6.11 An additional equivalent of t-butyllithium could then
add to 6 to yield sulfur-stabilized anion 7. Subsequent elimina-
tion of lithium p-toluenesulfinate would furnish thioimidate 5.
Hydrolysis of thioimidate 5 provided t-butyl-substituted thio-
amide 8 in 92% yield. Attempts to obtain 6 in high yield failed.
For instance, treatment of 3c with 1.2 molar amount of t-butyl-
lithium in THF at ꢁ40 ꢂC afforded 6 in only 34% NMR yield.
Unfortunately, the use of other organolithium or -magnesium
compounds instead of t-butyllithium gave complex mixtures.
When ynamide 1a was treated with thiobenzoic acid (9) in-
stead of 2 under conditions that were otherwise the same, ke-
tene N,O-acetal 10 was obtained in 51% yield (Scheme 4). Re-
action of 10 with butylmagnesium bromide in THF afforded
amide 11, which suggests that the adduct 10 was not S-alkenyl
thioester but O-alkenyl thioester. On the other hand, treatment
of ynamide 1a with thiols such as benzenethiol and 1-dodec-
anethiol resulted in no hydrothiolation reactions, which clearly
shows the importance of the acidity of the reagents.12 Hydro-
thiolation with aromatic dithiocarboxylic acid could not be
performed due to difficulty in preparing and purifying dithio-
carboxylic acid.
H
+
N
SO2Ar
S
P
−
Ph
C
C
R2
4
R1
S
Ph
2−
R1 = Me, Ar, SiMe3
Figure 1. Stereoselective addition of 2ꢁ to ketene iminium
intermediate.
obtained as a 1:1 mixture of the E and Z isomers, which sug-
gests a stepwise mechanism for the hydrothiolation as outlined
in Scheme 2. Protonation of 1h-d with 2 would generate a ke-
tene iminium intermediate 4h-d and diphenyldithiophosphi-
nate anion 2ꢁ. The anion 2ꢁ would then attack the intermedi-
ate 4h-d to afford (E)- and (Z)-3h-d. Instead of the addition of
2ꢁ to 4h-d, abstraction of the deuterium in 4h-d by 2ꢁ would
generate 1h and 2-d. The generation of 1h and 2-d resulted in
the formations of unlabeled 3h and 3h-d2, respectively.
The selective formation of E isomers from 1a–1g, 1i, and 1j
is rationalized as shown in Figure 1. Dithiophosphinate anion
2ꢁ would approach a ketene iminium intermediate 4 from the
same side of the olefinic hydrogen to avoid steric repulsion
between R1 and 2ꢁ.
We found that the reaction of ynamide 1a or 1b with di-
phenylphosphine and sulfur in the presence of a catalytic
amount of butyllithium in DME at 25 ꢂC afforded 3a or 3b,
S
tBuLi
(4.0 mol. amt.)
StBu
tBu
Ph
Li
StBu
N Ts
Me
S PPh2
Ph
N Ts
Me
Et2O, 0 °C
Ph
N Ts
Me
1 h, 80%
3a
6
7
tBu
Ph
S
tBu
Ph
StBu
N Me
1M HCl aq.
THF, 25 °C,
N Me
1 h, 92%
H
8
5 (d.r. = 93:7)
Scheme 3. Transformation of 3.

508 Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
Hydrothiolation of Electron-Rich Alkynes
Table 2. Hydrothiolation of 1-Alkynyl Sulfides 12 with
Diphenyldithiophosphinic Acid (2)
S
Ts
O
O
+
Ph C C N
Ph
N Ts
S
P
DME, 25 °C,
HS
Ph
Me
Ph
1 h, 51%
9
1a
Me
HS
Ph
S
(1.2 mol. amt.)
Ph
2
10(E/Z = 92:8)
S PPh2
(1.2 mol. amt.)
R1 C C SR2
O
nBuMgBr (2.2 mol. amt.)
Ph
Ts
ethanol, 25 °C, 5 h
SR2 13
R1
12
N
THF, −20 °C to 0 °C
66%
11 Me
Entry 12 R1
R2
13 Yield/%a) E/Z
Scheme 4. Addition of thiobenzoic acid to 1a.
1
2
3
4
5
6
7
8
9
12a Ph
12b Ph
nC12H25
13a
96
85
92
86
91
83b)
86
92
97
57
97:3
100:0
83:17
97:3
99:1
98:2
95:5
94:6
97:3
—
p-MeC6H4 13b
nC12H25
13c
p-MeC6H4 13d
Addition to 1-Alkynyl Sulfides. The results of the hydro-
thiolation of 1-alkynyl sulfides 12 with 2 are summarized in
Table 2. The scope of 1-alkynyl sulfides is wide enough to af-
ford a variety of ketene S,S-acetals 13 in excellent yield. The
syn addition predominated to yield E isomers as major prod-
ucts. The E configuration was assigned by X-ray crystallo-
graphic analysis of 13b. However, the reactions of 12 showed
poorer stereoselectivity than those of N-1-alkynylamide 1. The
SR2 groups are sterically less hindered than the NR2(SO2Ar)
groups, which would partly allow dithiophosphinate anion 2ꢁ
to attack the cationic thioketene intermediate from the same
side of the R1 group. The reaction of dodecyl ethynyl sulfide
(12j) provided the corresponding product 13j in 57% yield,
along with dodecyl dithioacetate (CH3C(=S)SnC12H25, 29%),
which would be formed by hydrolysis of 13j (Entry 10). Sol-
vent effect on the reaction is almost negligible, and the reac-
tion proceeded as well in solvents such as DME and dichloro-
methane.
12c nC6H13
12d nC6H13
n
12e p-MeOC6H4 C12H25
n
13e
13f
13g
13h
13i
13j
12f o-MeOC6H4 C12H25
12g p-CF3C6H4 nC12H25
12h cC6H11
12i tC4H9
nC12H25
nC12H25
nC12H25
10 12j
H
a) Isolated yields by silica gel column chromatography unless
otherwise noted. b) Isolated yield obtained by using gel per-
meation chromatography.
Conclusion
We examined hydrothiolation reactions of ynamides and 1-
alkynyl sulfides with diphenyldithiophosphinic acid. The reac-
tion proved to proceed in syn fashions, yielding (E)-ketene
N,S-acetals and S,S-acetals of synthetic use. The reactions be-
gin with protonation of the electron-rich alkynes followed by
nucleophilic addition of diphenyldithiophosphinate anion.
Treatment of 13a with trifluoroacetic acid in dichloro-
methane afforded the corresponding dithioester 14 in high
yield (eq 2).
Experimental
S
CF3CO2H
(5.0 mol. amt.)
General. 1H NMR (500 MHz) and 13C NMR (125.7 MHz)
spectra were taken on a Varian UNITY INOVA 500 spectrometer
and were obtained in CDCl3 with tetramethylsilane as an internal
standard. 31P NMR (121.5 MHz) spectra were taken on a Varian
GEMINI 300 spectrometer and were obtained in CDCl3 with
85% H3PO4 solution as an external standard. NMR yields were
determined by fine 31P NMR spectra with (MeO)3P=O as an inter-
nal standard. The first delay of 31P NMR measurements was set for
15 s to make integrals for signals accurate. IR spectra were taken
on a SHIMADZU FTIR-8200PC spectrometer. Mass spectra were
determined on a JEOL Mstation 700 spectrometer. TLC analyses
were performed on commercial glass plates bearing a 0.25-mm
layer of Merck Silica gel 60F254. Silica gel (Wakogel 200 mesh)
was used for column chromatography unless otherwise noted. Pu-
rification of 15 was performed on Silica Gel 60 N (spherical, neu-
tral), which is available from Kanto Chemical Co., Inc., by using
hexane/ethyl acetate/triethylamine = 93:2:5 as an eluent. Gel
permeation chromatography was performed by using LC-908
(Japan Analytical Industry Ltd., two in-line JAIGEL-2H, toluene,
3.8 mL minꢁ1, UV and RI detectors). Elemental analyses were
carried out at the Elemental Analysis Center of Kyoto University.
Material. Materials obtained from commercial suppliers were
used without further purification. Ynamide 1g was prepared by a
procedure described in the literature.13 Ynamide 1h and 1h-d were
prepared by treatment of 1g with an excess amount of potassium
carbonate in methanol or methanol-d1. Preparation of other yna-
S
H
S PPh2
ð2Þ
SnC12H25
CH2Cl2, 25 °C, 4h
Ph
SnC12H25
Ph
13a (E/Z = 97:3)
14 85%
Organolithium reagents reacted with 13a at the diphenyl-
thiophosphinylated sulfur atom, leading to substitution reac-
tions.11 The reactions of 13a with phenyllithium and butyllithi-
um yielded 15a and 15b, respectively. Although the reactions
proceeded with retention of configuration with 13a, the prod-
ucts 15a and 15b readily underwent isomerization on silica
gel upon chromatographic purification. To avoid the isomeri-
zation, 15a was chromatographed on neutral silica gel with
hexane/ethyl acetate/triethylamine = 93:2:5 as an eluent. The
isomerization of 15b was inevitable with various eluents
tested.
S
PhLi or nBuLi
(1.0 mol. amt.)
H
S PPh2
H
SR
SnC12H25
Ph
SnC12H25
THF, 0 °C, 30 min
then purification
on silica gel
Ph
ð3Þ
13a (E/Z = 97:3)
15a (R = Ph)
67%, E/Z = 95:5
15b (R = nBu)
67%, E/Z = 32:68

S. Kanemura et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
509
mides 1a–1f, 1i, and 1j were performed according to the litera-
ture.14 Diphenyldithiophosphinic acid (2) was easily prepared
from benzene and P4S10 in the presence of AlCl3.15 1-Alkynyl sul-
fides 12 were prepared according to the procedure described be-
low. Butyllithium was purchased from Nacalai Tesque. Phenyl-
lithium and t-butyllithium were obtained from Kanto Chemical.
General Procedure for the Hydrothiolation Reactions of
Ynamides with Diphenyldithiophosphinic Acid (Table 1).
Ynamide 1h (0.11 g, 0.50 mmol) was placed in a 30-mL reaction
flask under argon. A solution of 2 (0.15 g, 0.60 mmol in 5 mL of
DME) was added to the reaction flask at room temperature. The
mixture was stirred for 1 h at room temperature. The resulting
mixture was concentrated in vacuo. 31P NMR analysis with tri-
methyl phosphate as an internal standard revealed formation of
the corresponding product 3h in 91% yield. Purification of the
crude product by silica gel column chromatography provided 3h
(0.20 g, 0.43 mmol) in 86% yield as white crystal.
Hydrothiolation of Ynamides with Diphenylphosphine and
Sulfur in the Presence of a Catalytic Amount of Butyllithium
(eq 1). The reaction of ynamide 1b is representative. DME
(3 mL), butyllithium (1.6 mol Lꢁ1, 31 mL, 0.050 mmol), and fresh-
ly distilled diphenylphosphine (0.13 mL, 0.75 mmol) were sequen-
tially added to a 50-mL reaction flask under argon at room temper-
ature. After the reaction mixture was stirred for 10 min at room
temperature, S8 (0.05 g) and ynamides 1b (0.11 g, 0.5 mmol, dis-
solved in 3 mL of DME) were successively added. The resulting
mixture was stirred at room temperature for 1 h, and saturated
NH4Cl aq (2 mL) was added. The organic compounds were ex-
tracted with ethyl acetate twice. The combined organic part was
washed with brine and dried over anhydrous sodium sulfate. After
evaporation, the resulting residue was purified by silica gel col-
umn chromatography to afford 3b (185 mg, 0.39 mmol) in 78%
yield.
mixture was poured into water (20 mL), and the product was ex-
tracted with ethyl acetate (20 mL ꢃ 3). The combined organic lay-
er was dried over anhydrous sodium sulfate and concentrated in
vacuo. Purification of the residual oil on silica gel afforded 12a
(1.8 g, 6.1 mmol, 76%) as a white solid.
Hydrothiolation of 1-Alkynyl Sulfides 12 (Table 2). The
reaction of 12a with 2 is representative. Ethanol (3.0 mL), 12a
(0.15 g, 0.50 mmol), and 2 (0.15 g, 0.60 mmol) were added to a
20-mL reaction flask under an argon atmosphere. The mixture
was stirred for 5 h at 25 ꢂC, and concentrated in vacuo. Silica
gel column purification afforded 13a (0.27 g, 0.48 mmol, 96%)
as a pale yellow oil.
Reaction of S,S-Acetal 13a with Trifluoroacetic Acid
(eq 2). Dichloromethane (2.0 mL), 13a (0.11 g, 0.20 mmol), and
trifluoroacetic acid (0.074 mL, 1.0 mmol) were added to a 20-mL
reaction flask under an argon atmosphere. The mixture was stirred
for 4 h at 25 ꢂC, and concentrated in vacuo. Chromatographic pu-
rification on silica gel afforded 14 (0.058 g, 0.17 mmol, 85%) as a
pale yellow oil.
Reaction of 13a with Organolithium Reagent (eq 3). Ke-
tene S,S-acetal 13a (0.28 g, 0.50 mmol) and THF (3.0 mL) were
placed in a 20-mL reaction flask under argon. Phenyllithium
(1.1 mol Lꢁ1 hexane–cyclohexane solution, 0.44 mL, 0.50 mmol)
was added to the solution at 0 ꢂC. After being stirred at 0 ꢂC for
30 min, the mixture was poured into water (10 mL). The product
was extracted with ethyl acetate (10 mL ꢃ 3). The combined or-
ganic layer was dried over anhydrous sodium sulfate. After evap-
oration, the crude oil was purified by silica gel column chromatog-
raphy to afford 15a (0.14 g, 0.34 mmol) in 67% yield.
Characterization Data. The spectral data of 1g,13 1i,14 12b,17
and 12d18 are identical to those found in the literature.
N-Methyl-N-phenylethynyl-p-toluenesulfonamide (1a): IR
(nujol) 2924, 2233, 1595, 1365, 1164, 764, 676, 546 cmꢁ1
;
Reaction of 3a with t-Butyllithium (Scheme 3). Ketene N,S-
acetal 3a (0.16 g, 0.30 mmol) was placed in a 30-mL reaction
flask under argon. Diethyl ether (5 mL) and t-butyllithium (1.58
mol Lꢁ1, 0.76 mL, 1.2 mmol) were sequentially added at 0 ꢂC.
After being stirred for 1 h at 0 ꢂC, water (5 mL) was added. The
organic compounds were extracted with ethyl acetate twice. The
combined organic part was washed with brine and dried over an-
hydrous sodium sulfate. After evaporation, the resulting residue
was purified by silica gel column chromatography to afford thio-
imidate 5 (0.067 g, 0.24 mmol) in 80% yield.
1H NMR (CDCl3) ꢀ 2.46 (s, 3H), 3.15 (s, 3H), 7.27–7.31 (m,
3H), 7.34–7.38 (m, 4H), 7.83–7.85 (m, 2H); 13C NMR (CDCl3)
ꢀ 21.85, 39.49, 69.19, 84.11, 122.87, 128.02, 128.04, 128.44,
129.98, 131.57, 133.40, 144.97; Anal. Found: C, 67.07; H,
5.25%. Calcd for C16H15NO2S: C, 67.34; H, 5.30%; mp 85–86 ꢂC.
N-Methyl-N-1-propynyl-p-toluenesulfonamide (1b):
(nujol) 2924, 2855, 2265, 1456, 1355, 1168, 1158, 1042, 816,
677, 566, 545 cmꢁ1 1H NMR (CDCl3) ꢀ 1.88 (s, 3H), 2.46 (s,
IR
;
3H), 3.01 (s, 3H), 7.34–7.39 (m, 2H), 7.76–7.81 (m, 2H);
13C NMR (CDCl3) ꢀ 3.39, 21.83, 39.43, 64.26, 73.90, 127.97,
129.87, 133.49, 144.64; Anal. Found: C, 59.16; H, 5.82%. Calcd
for C11H13NO2S: C, 59.17; H, 5.87%; mp 99–100 ꢂC.
Hydrolysis of Thioimidate (Scheme 3).
Thioimidate 5
(0.065 g, 0.23 mmol) was placed in a 30-mL reaction flask under
argon. THF (3 mL) and hydrochloric acid (1.0 mol Lꢁ1, 3 mL)
were sequentially added at ambient temperature. After the mixture
was stirred for 1 h at ambient temperature, water (5 mL) was add-
ed. The organic compounds were extracted with ethyl acetate
twice. The combined organic part was washed with brine and
dried over anhydrous sodium sulfate. After evaporation, the result-
ing residue was purified by silica gel column chromatography to
afford thioamide 8 (0.048 g, 0.22 mmol) in 92% yield.
N-Methyl-N-p-tolylethynyl-p-toluenesulfonamide (1c): IR
(nujol) 2922, 2854, 2232, 1366, 1166, 728, 664, 567, 543 cmꢁ1
;
1H NMR (CDCl3) ꢀ 2.35 (s, 3H), 2.48 (s, 3H), 3.16 (s, 3H), 7.11
(d, J ¼ 8:0 Hz, 2H), 7.24–7.32 (m, 2H), 7.38 (d, J ¼ 8:0 Hz, 2H),
7.85 (d, J ¼ 8:0 Hz, 2H); 13C NMR (CDCl3) ꢀ 21.60, 21.83,
39.53, 69.15, 83.39, 119.69, 128.05, 129.20, 129.94, 131.66,
133.40, 138.21, 144.90; Anal. Found: C, 68.20; H, 5.60%. Calcd
for C17H17NO2S: C, 68.20; H, 5.72%; mp 73–74 ꢂC.
Synthesis of 1-Alkynyl Sulfides. The synthesis of dodecyl
phenylethynyl sulfide (12a) is representative. THF (15 mL) was
placed in a 50-mL reaction flask under argon. At 0 ꢂC, phenylacet-
ylene (0.99 mL, 9.0 mmol) and butyllithium (1.6 mol Lꢁ1 hexane
solution, 5.2 mL, 8.5 mmol) were sequentially added. After the
mixture was stirred for 30 min at 0 ꢂC, didodecyl disulfide
(3.2 g, 8.0 mmol) was added. The mixture was stirred for 1 h at
room temperature. 2-Bromoethanol (0.71 mL, 10 mmol) was then
added,16 and the resulting mixture was stirred for 30 min. The
N-Methyl-N-o-tolylethynyl-p-toluenesulfonamide (1d): IR
(neat) 2923, 2235, 1597, 1457, 1367, 1189, 1169, 962, 811,
1
758, 735, 676, 547 cmꢁ1; H NMR (CDCl3) ꢀ 2.37 (s, 3H), 2.46
(s, 3H), 3.18 (s, 3H), 7.08–7.14 (m, 1H), 7.17 (dd, J ¼ 5:0, 1.5
Hz, 2H), 7.31 (d, J ¼ 7:5 Hz, 1H), 7.34–7.38 (m, 2H), 7.82–7.87
(m, 2H); 13C NMR (CDCl3) ꢀ 20.88, 21.93, 39.64, 68.21, 87.91,
122.70, 125.66, 127.92, 128.02, 129.56, 129.99, 131.55, 133.59,
139.91, 144.95; HRMS(EI) Found: 299.0986. Calcd for C17H17-
NO2S: 299.0980 [Mþ].

510 Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
Hydrothiolation of Electron-Rich Alkynes
N-p-Chlorophenylethynyl-N-methyl-p-toluenesulfonamide
(1e): IR (nujol) 2925, 2855, 2239, 1362, 1163, 1087, 960, 827,
phenyldithiophosphinate (3c): IR (nujol) 2923, 2854, 1433,
1
1335, 1160, 1095, 975, 815, 686 cmꢁ1; H NMR (CDCl3) ꢀ 2.33
1
691 cmꢁ1; H NMR (CDCl3) ꢀ 2.46 (s, 3H), 3.15 (s, 3H), 7.24–
(s, 3H), 2.46 (s, 3H), 2.57 (s, 3H), 6.76 (d, J ¼ 3:5 Hz, 1H), 7.10
(d, J ¼ 8:5 Hz, 2H), 7.26–7.58 (m, 6H), 7.28 (d, J ¼ 8:0 Hz, 2H),
7.38 (d, J ¼ 8:0 Hz, 2H), 7.69–7.96 (m, 6H); 13C NMR (CDCl3) ꢀ
21.59, 21.79, 35.31, 124.52 (d, J ¼ 8:1 Hz), 128.58, 128.69 (d,
J ¼ 13:4 Hz), 129.35, 129.57 (d, J ¼ 1:4 Hz), 129.60, 131.27 (d,
J ¼ 2:9 Hz), 131.90 (d, J ¼ 11:0 Hz), 132.13 (d, J ¼ 3:4 Hz),
134.44 (d, J ¼ 83:1 Hz), 135.35, 139.74, 143.96, 147.02 (d, J ¼
7:1 Hz); 31P NMR (CDCl3) ꢀ 64.87; Anal. Found: C, 63.19; H,
5.01%. Calcd for C29H28NO2PS3: C, 63.36; H, 5.13%; mp 144–
146 ꢂC.
(E)-1-[Methyl(p-tolylsulfonyl)amino]-2-o-tolylethenyl Di-
phenyldithiophosphinate (3d): IR (nujol) 2924, 2854, 1436,
1356, 1167, 1156, 1101, 723, 652 cmꢁ1; 1H NMR (CDCl3) ꢀ 2.11
(s, 3H), 2.39 (s, 3H), 2.57 (s, 3H), 6.90 (s, 1H), 7.02–7.26 (m, 5H),
7.30–7.66 (m, 9H), 7.78–8.02 (m, 4H); 13C NMR (CDCl3) ꢀ
20.21, 21.68, 35.83, 125.97, 127.15, 128.33, 128.46 (d, J ¼ 1:4
Hz), 128.72 (d, J ¼ 12:9 Hz), 128.87, 129.43, 130.02, 131.90 (d,
J ¼ 11:0 Hz), 132.16 (d, J ¼ 2:9 Hz), 133.42, 134.21 (d, J ¼
83:5 Hz), 135.41, 137.09, 143.78, 143.84; 31P NMR (CDCl3) ꢀ
64.35; Anal. Found: C, 63.54; H, 5.27%. Calcd for C29H28NO2-
PS3: C, 63.36; H, 5.13%; mp 165–167 ꢂC.
7.30 (m, 4H), 7.36–7.40 (m, 2H), 7.80–7.85 (m, 2H); 13C NMR
(CDCl3) ꢀ 21.83, 39.38, 68.28, 85.00, 121.41, 127.99, 128.76,
130.02, 132.73, 133.41, 133.96, 145.10; Anal. Found: C, 59.81;
H, 4.45%. Calcd for C16H14NO2SCl: C, 60.09; H, 4.41%; mp
95–97 ꢂC.
N-p-Acetylphenylethynyl-N-methyl-p-toluenesulfonamide
(1f): IR (nujol) 2925, 2232, 1676, 1603, 1370, 1352, 1269, 1177,
1168, 714, 658 cmꢁ1 1H NMR (CDCl3) ꢀ 2.47 (s, 3H), 2.59 (s,
;
3H), 3.18 (s, 3H), 7.36–7.44 (m, 4H), 7.82–7.86 (m, 2H), 7.86–
7.91 (m, 2H); 13C NMR (CDCl3) ꢀ 21.87, 26.75, 39.38, 69.33,
87.70, 128.00, 128.13, 128.44, 130.11, 130.96, 133.44, 135.81,
145.25, 197.44; Anal. Found: C, 65.87; H, 5.39%. Calcd for C18-
H17NO3S: C, 66.03; H, 5.23%; mp 131–133 ꢂC.
N-Ethynyl-N-methyl-p-toluenesulfonamide (1h): IR (nujol)
2923, 2360, 2137, 1597, 1359, 1172, 960, 691 cmꢁ1 1H NMR
;
(CDCl3) ꢀ 2.46 (s, 3H), 2.68 (s, 1H), 3.06 (s, 3H), 7.37 (d,
J ¼ 7:5 Hz, 2H), 7.80 (d, J ¼ 7:5 Hz, 2H); 13C NMR (CDCl3) ꢀ
21.84, 39.01, 57.63, 77.76, 128.00, 130.01, 133.41, 145.09; Anal.
Found: C, 57.35; H, 5.47%. Calcd for C10H11NO2S: C, 57.40; H,
5.30%; mp 75–76 ꢂC.
N-Methyl-N-phenylethynyl-p-nitrobenzenesulfonamide (1j):
IR (nujol) 2953, 2924, 2854, 2242, 1607, 1531, 1446, 1371, 1347,
1171, 769, 759, 598 cmꢁ1; 1H NMR (CDCl3) ꢀ 3.23 (s, 3H), 7.28–
7.40 (m, 5H), 8.15 (d, J ¼ 8:5 Hz, 2H), 8.44 (d, J ¼ 8:5 Hz, 2H);
13C NMR (CDCl3) ꢀ 39.80, 69.99, 82.63, 122.04, 124.66, 128.62,
128.66, 129.22, 131.82, 141.82, 150.94; Anal. Found: C, 57.04;
H, 3.88%. Calcd for C15H12N2O4S: C, 56.95; H, 3.82%; mp
150–153 ꢂC.
(E)-2-p-Chlorophenyl-1-[methyl(p-tolylsulfonyl)amino]eth-
enyl Diphenyldithiophosphinate (3e): IR (nujol) 2924, 2855,
1437, 1351, 1162, 1090, 971, 815, 689 cmꢁ1 1H NMR (CDCl3)
;
ꢀ 2.45 (s, 3H), 2.57 (s, 3H), 6.73 (d, J ¼ 3:0 Hz, 1H), 7.22–7.58
(m, 12H), 7.67 (d, J ¼ 8:5 Hz, 2H), 7.72–7.90 (m, 4H); 13C NMR
(CDCl3) ꢀ 21.78, 35.33, 126.70 (d, J ¼ 8:6 Hz), 128.51, 128.70,
128.81, 128.83, 129.70, 130.75, 131.88 (d, J ¼ 10:9 Hz), 132.24
(d, J ¼ 3:4 Hz), 132.55 (d, J ¼ 2:9 Hz), 134.27 (d, J ¼ 83:1 Hz),
135.12, 144.22, 145.21 (d, J ¼ 7:1 Hz); 31P NMR (CDCl3) ꢀ
65.48; Anal. Found: C, 59.11; H, 4.43%. Calcd for C28H25Cl-
NO2PS3: C, 58.99; H, 4.42%; mp 109–111 ꢂC.
(E)-2-p-Acetylphenyl-1-[methyl(p-tolylsulfonyl)amino]eth-
enyl Diphenyldithiophosphinate (3f): IR (nujol) 2923, 2854,
1682, 1347, 1266, 1162, 973, 719, 682 cmꢁ1; 1H NMR (CDCl3) ꢀ
2.45 (s, 3H), 2.58 (s, 3H), 2.60 (s, 3H), 6.80 (d, J ¼ 3:0 Hz, 1H),
7.24–7.30 (m, 2H), 7.32–7.60 (m, 8H), 7.66–7.70 (m, 2H), 7.74–
7.92 (m, 6H); 13C NMR (CDCl3) ꢀ 21.81, 26.82, 35.44, 128.53,
128.62, 128.68, 128.81 (d, J ¼ 13:3 Hz), 129.56 (d, J ¼ 1:4 Hz),
129.74, 131.92 (d, J ¼ 11:0 Hz), 132.34 (d, J ¼ 2:9 Hz), 134.14
(d, J ¼ 83:5 Hz), 134.97, 137.10, 138.60 (d, J ¼ 2:9 Hz), 144.30,
144.91 (d, J ¼ 7:3 Hz), 197.60; 31P NMR (CDCl3) ꢀ 65.70; Anal.
Found: C, 62.25; H, 4.86%. Calcd for C30H28NO3PS3: C, 62.37;
H, 4.89%; mp 132–134 ꢂC.
N-Deuterioethynyl-N-methyl-p-toluenesulfonamide (1h-d):
IR (nujol) 2923, 2580, 2000, 1596, 1358, 1171, 955, 689, 544
1
cmꢁ1; H NMR (CDCl3) ꢀ 2.45 (s, 3H), 3.05 (s, 3H), 7.34–7.49
(m, 2H), 7.78–7.82 (m, 2H); 13C NMR (CD2Cl2) ꢀ 21.94, 39.45,
57.48 (t, J ¼ 40:1 Hz), 77.74 (t, J ¼ 9:0 Hz), 128.30, 130.42,
133.65, 145.82; Anal. Found: C, 57.05; H þ D, 5.61%. Calcd for
C10H10DNO2S: C, 57.12; H þ D, 5.75%; mp 74–76 ꢂC.
(E)-1-[Methyl(p-tolylsulfonyl)amino]-2-phenylethenyl Di-
phenyldithiophosphinate (3a): IR (nujol) 2924, 2855, 1437,
1351, 1163, 693, 654 cmꢁ1; 1H NMR (CDCl3) ꢀ 2.44 (s, 3H), 2.56
(s, 3H), 6.80 (d, J ¼ 3:5 Hz, 1H), 7.22–7.54 (m, 13H), 7.69 (d,
J ¼ 8:5 Hz, 2H), 7.73–7.89 (m, 4H); 13C NMR (CDCl3) ꢀ 21.77,
35.34, 125.73 (d, J ¼ 8:1 Hz), 128.44, 128.51, 128.62 (d, J ¼
12:9 Hz), 129.31, 129.41 (d, J ¼ 0:9 Hz), 129.54, 131.75 (d, J ¼
11:0 Hz), 132.11 (d, J ¼ 2:9 Hz), 133.91 (d, J ¼ 2:9 Hz), 134.19
(d, J ¼ 83:1 Hz), 135.09, 143.98, 146.65 (d, J ¼ 7:1 Hz); 31P NMR
(CDCl3) ꢀ 65.09; Anal. Found: C, 62.78; H, 4.93%. Calcd for
C28H26NO2PS3: C, 62.78; H, 4.89%; mp 128–129 ꢂC.
(E)-1-[Methyl(p-tolylsulfonyl)amino]-2-(trimethylsilyl)eth-
enyl Diphenyldithiophosphinate (3g): Purification by recrystal-
lization from a mixture of hexane and benzene was performed in-
stead of silica gel column chromatography. IR (nujol) 2924, 2854,
1439, 1348, 1245, 1166, 1157, 1103, 966, 864, 847, 721, 610
(E)-1-[Methyl(p-tolylsulfonyl)amino]-1-propenyl Diphenyl-
dithiophosphinate (3b):
IR (neat) 3055, 2923, 1597, 1436,
1H NMR
1351, 1167, 1089, 957, 815, 720, 675, 654, 609 cmꢁ1
;
cmꢁ1 1H NMR (CDCl3) ꢀ 0.15 (s, 9H), 2.44 (s, 3H), 2.70 (s,
;
(CDCl3) ꢀ 1.75 (dd, J ¼ 7:0, 4.5 Hz, 3H), 2.45 (s, 3H), 2.54 (s,
3H), 6.13 (dq, J ¼ 7:0, 3.5 Hz, 1H), 7.29–7.35 (m, 2H), 7.42 (br,
4H), 7.46–7.53 (m, 2H), 7.66–7.72 (m, 2H), 7.78–7.86 (m, 4H);
13C NMR (CDCl3) ꢀ 16.07 (d, J ¼ 2:4 Hz), 21.79, 35.78, 126.47
(d, J ¼ 7:6 Hz), 128.16, 128.69 (d, J ¼ 13:4 Hz), 129.77, 131.87
(br), 132.11 (d, J ¼ 3:4 Hz), 134.44 (d, J ¼ 84:5 Hz), 135.58,
143.91, 147.52 (d, J ¼ 7:1 Hz); 31P NMR (CDCl3) ꢀ 64.47; Anal.
Found: C, 58.39; H, 5.12%. Calcd for C23H24NO2PS3: C, 58.33;
H, 5.11%; mp 83–84 ꢂC.
3H), 6.05 (d, J ¼ 2:5 Hz, 1H), 7.31 (d, J ¼ 8:0 Hz, 2H), 7.35–
7.55 (m, 6H), 7.66–7.71 (m, 2H), 7.74–7.85 (m, 4H); 13C NMR
(CDCl3) ꢀ ꢁ0:61, 21.80, 36.06, 128.52, 128.69 (d, J ¼ 13:3
Hz), 129.77, 132.01 (d, J ¼ 10:5 Hz), 132.13 (d, J ¼ 3:3 Hz),
134.15 (d, J ¼ 83:9 Hz), 134.93, 136.27 (d, J ¼ 6:4 Hz), 144.04,
151.42 (d, J ¼ 5:1 Hz); 31P NMR (CDCl3) ꢀ 64.19; Anal. Found:
C, 56.20; H, 5.64%. Calcd for C25H30NO2SiPS3: C, 56.47; H,
5.69%; mp 160–162 ꢂC.
1-[Methyl(p-tolylsulfonyl)amino]ethenyl Diphenyldithio-
phosphinate (3h): IR (nujol) 2925, 2855, 2360, 1601, 1345,
(E)-1-[Methyl(p-tolylsulfonyl)amino]-2-p-tolylethenyl Di-

S. Kanemura et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
511
IR
1152, 930, 718, 668 cmꢁ1; H NMR (CDCl3) ꢀ 2.41 (s, 3H), 2.70
(s, 3H), 5.49 (dd, J ¼ 3:5, 1.5 Hz, 1H), 5.55 (dd, J ¼ 3:5, 1.5 Hz,
1H), 7.26–7.32 (m, 2H), 7.42–7.54 (m, 6H), 7.62–7.67 (m, 2H),
7.91–7.99 (m, 4H); 13C NMR (CDCl3) ꢀ 21.70, 37.08, 128.11,
128.36 (d, J ¼ 6:6 Hz), 128.74 (d, J ¼ 13:4 Hz), 129.70, 131.98
(d, J ¼ 11:0 Hz), 132.28 (d, J ¼ 2:9 Hz), 133.53 (d, J ¼ 84:0
Hz), 134.10, 136.21 (d, J ¼ 7:3 Hz), 144.11; 31P NMR (CDCl3)
ꢀ 63.97; Anal. Found: C, 57.24; H, 4.92%. Calcd for C22H22-
NO2PS3: C, 57.49; H, 4.82%; mp 99–100 ꢂC.
(E)-2-Phenyl-1-[(2-propenyl)(p-tolylsulfonyl)amino]ethenyl
Diphenyldithiophosphinate (3i): IR (nujol) 2924, 2854, 1358,
1167, 1101, 723 cmꢁ1; 1H NMR (CDCl3) ꢀ 2.40 (s, 3H), 3.72 (br,
2H), 4.85–4.92 (m, 1H), 4.94–5.02 (m, 1H), 5.64 (ddt, J ¼ 17:0,
10.0, 7.0 Hz, 1H), 6.79 (d, J ¼ 2:5 Hz, 1H), 7.17–7.27 (m, 5H),
7.30–7.54 (m, 8H), 7.70 (d, J ¼ 8:0 Hz, 2H), 7.76–7.94 (m, 4H);
13C NMR (CDCl3) ꢀ 21.73, 52.22, 118.83, 125.32 (d, J ¼ 8:1 Hz),
128.30, 128.63, 128.75 (d, J ¼ 13:3 Hz), 129.29, 129.57, 129.83
(d, J ¼ 1:0 Hz), 131.95 (d, J ¼ 11:0 Hz), 132.21 (d, J ¼ 3:3 Hz),
132.98, 134.04, 134.30 (d, J ¼ 83:5 Hz), 136.00, 144.09, 146.96
(d, J ¼ 6:8 Hz); 31P NMR (CDCl3) ꢀ 64.31; Anal. Found: C,
64.12; H, 5.09%. Calcd for C30H28NO2PS3: C, 64.15; H, 5.02%;
mp 132–134 ꢂC.
N-Methyl-N-(p-tolylsulfonyl)phenylacetamide (11):
;
(neat) 3031, 1696, 1356, 1167, 1075, 673, 583 cmꢁ1 1H NMR
1
(CDCl3) ꢀ 2.44 (s, 3H), 3.28 (s, 3H), 4.04 (s, 2H), 7.11–7.16 (m,
2H), 7.22–7.34 (m, 5H), 7.67–7.72 (m, 2H); 13C NMR (CDCl3)
21.78, 33.43, 43.23, 127.33, 127.69, 128.75, 129.54, 130.04,
133.62, 136.20, 145.12, 171.44; Anal. Found: C, 63.05; H, 5.66%.
Calcd for C16H17NO3S: C, 63.34; H, 5.65%.
Dodecyl Phenylethynyl Sulfide (12a): IR (neat) 2925, 2854,
2168, 1596, 1488, 1466, 753, 690 cmꢁ1; 1H NMR (CDCl3) ꢀ 0.89
(t, J ¼ 7:0 Hz, 3H), 1.24–1.38 (m, 16H), 1.42–1.50 (m, 2H), 1.77–
1.84 (m, 2H), 2.81 (t, J ¼ 7:5 Hz, 2H), 7.27–7.34 (m, 3H), 7.39–
7.44 (m, 2H); 13C NMR (CDCl3) ꢀ 14.10, 22.67, 28.26, 29.11,
29.32, 29.33, 29.48, 29.57, 29.61, 29.64, 31.90, 35.82, 79.71,
92.83, 123.60, 127.88, 128.22, 131.37. Anal. Found: C, 79.54; H,
10.24%. Calcd for C20H30S: C, 79.41; H, 9.99%.
Dodecyl 1-Octynyl Sulfide (12c): IR (neat) 2956, 2926, 2855,
1467, 1378, 722 cmꢁ1
;
1H NMR (CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz,
3H), 0.89 (t, J ¼ 7:5 Hz, 3H), 1.20–1.34 (m, 20H), 1.35–1.44 (m,
4H), 1.47–1.54 (m, 2H), 1.68–1.75 (m, 2H), 2.29 (t, J ¼ 7:0 Hz,
2H), 2.65 (t, J ¼ 7:5 Hz, 2H); 13C NMR (CDCl3) ꢀ 14.02, 14.09,
20.12, 22.55, 22.68, 28.29, 28.51, 28.77, 29.15, 29.24, 29.34,
29.50, 29.59, 29.63, 29.65, 31.33, 31.91, 35.45, 68.31, 94.23.
Anal. Found: C, 77.14; H, 12.58%. Calcd for C20H38S: C, 77.34;
H, 12.33%.
(E)-1-[Methyl(p-nitrophenylsulfonyl)amino]-2-phenylethen-
yl Diphenyldithiophosphinate (3j):
IR (nujol) 2923, 2854,
1524, 1434, 1350, 1335, 1160, 718, 635 cmꢁ1; H NMR (CDCl3)
ꢀ 2.76 (s, 3H), 6.75 (d, J ¼ 3:0 Hz, 1H), 7.24–7.31 (m, 3H),
7.32–7.38 (m, 2H), 7.38–7.49 (m, 4H), 7.49–7.56 (m, 2H),
7.74–7.90 (m, 4H), 7.92–7.97 (m, 2H), 8.21–8.26 (m, 2H);
13C NMR (CDCl3) ꢀ 36.02, 124.11, 125.40 (d, J ¼ 8:1 Hz),
128.78, 128.86 (d, J ¼ 13:4 Hz), 129.31 (d, J ¼ 1:4 Hz), 129.64,
129.72, 131.87 (d, J ¼ 10:5 Hz), 132.44 (d, J ¼ 3:3 Hz), 133.72
(d, J ¼ 2:9 Hz), 134.03 (d, J ¼ 83:0 Hz), 144.09, 147.10 (d,
J ¼ 7:1 Hz), 150.33; 31P NMR (CDCl3) ꢀ 65.13; Anal. Found:
C, 57.42; H, 4.23%. Calcd for C27H23N2O4PS3: C, 57.23; H,
4.09%; mp 126–127 ꢂC.
Dodecyl p-Methoxyphenylethynyl Sulfide (12e): IR (neat)
2925, 2854, 1606, 1507, 1289, 1249, 1171, 1035, 830 cmꢁ1
1
;
1H NMR (CDCl3) ꢀ 0.89 (t, J ¼ 7:5 Hz, 3H), 1.20–1.36 (m, 16H),
1.40–1.47 (m, 2H), 1.75–1.82 (m, 2H), 2.78 (t, J ¼ 7:0 Hz, 2H),
3.80 (s, 3H), 6.82 (d, J ¼ 9:0 Hz, 2H), 7.37 (d, J ¼ 9:0 Hz, 2H);
13C NMR (CDCl3) ꢀ 14.09, 22.67, 28.28, 29.12, 29.30, 29.33,
29.48, 29.57, 29.61, 29.64, 31.89, 35.87, 55.23, 77.66, 92.54,
113.85, 115.69, 133.28, 159.49. Anal. Found: C, 75.91; H, 9.84%.
Calcd for C21H32OS: C, 75.85; H, 9.70%.
Dodecyl o-Methoxyphenylethynyl Sulfide (12f): IR (neat)
2925, 2854, 2171, 1594, 1490, 1464, 1258, 1115, 1027, 749
t-Butyl N,3,3-Trimethyl-2-phenylbutanethioimidate (5, a
93:7 Mixture of Diastereomers): IR (neat) 2957, 2905, 1629,
;
1452, 1392, 1364, 1163, 976, 725, 703 cmꢁ1 1H NMR (CDCl3)
ꢀ 1.01 (s, 9 ꢃ 0.93H), 1.10 (s, 9 ꢃ 0.07H), 1.36 (s, 9 ꢃ 0.93H),
1.56 (s, 9 ꢃ 0.07H), 3.25 (s, 3 ꢃ 0.07H), 3.53 (s, 3 ꢃ 0.93H),
3.90 (s, 1 ꢃ 0.93H), 4.03 (s, 1 ꢃ 0.07H), 7.20–7.33 (m, 3H),
7.36–7.44 (m, 2H); 13C NMR (CDCl3) ꢀ (major isomer) 28.66,
33.09, 36.60, 42.81, 49.02, 68.90, 126.53, 127.48, 131.32, 138.68,
162.42; Anal. Found: C, 73.47; H, 9.66%. Calcd for C17H27NS: C,
73.59; H, 9.81%.
cmꢁ1
;
1H NMR (CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz, 3H), 1.20–1.37
(m, 16H), 1.41–1.48 (m, 2H), 1.78–1.86 (m, 2H), 2.81 (t, J ¼
7:5 Hz, 2H), 3.86 (s, 3H), 6.83–6.90 (m, 2H), 7.22–7.27 (m, 1H),
7.35–7.39 (m, 1H); 13C NMR (CDCl3) ꢀ 14.10, 22.66, 28.30,
29.16, 29.22, 29.33, 29.49, 29.59, 29.61, 29.64, 31.89, 35.95,
55.72, 83.51, 89.03, 110.54, 112.85, 120.34, 129.27, 133.28,
159.98. Anal. Found: C, 76.13; H, 9.64%. Calcd for C21H32OS:
C, 75.85; H, 9.70%.
Dodecyl p-(Trifluoromethyl)phenylethynyl Sulfide (12g):
IR (neat) 2926, 2855, 2166, 1614, 1323, 1168, 1130, 1067, 840
cmꢁ1; 1H NMR (CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz, 3H), 1.20–1.38 (m,
16H), 1.40–1.50 (m, 2H), 1.77–1.84 (m, 2H), 2.83 (t, J ¼ 7:5 Hz,
2H), 7.46–7.49 (m, 2H), 7.52–7.56 (m, 2H); 13C NMR (CDCl3) ꢀ
14.08, 22.68, 28.22, 29.10, 29.35 (ꢃ2), 29.48, 29.58, 29.63, 29.66,
31.92, 35.82, 83.41, 91.84, 123.95 (q, J ¼ 270:6 Hz), 125.18 (q,
J ¼ 3:9 Hz), 127.42, 129.35 (q, J ¼ 32:4 Hz), 131.16. Anal.
Found: C, 68.34; H, 8.16%. Calcd for C21H29F3S: C, 68.07; H,
7.89%.
N,3,3-Trimethyl-2-phenylbutanethioamide (8): IR (nujol)
3370, 2925, 2867, 1520, 1365, 1297, 1098, 1053, 740, 711 cmꢁ1
;
1H NMR (CDCl3) ꢀ 1.11 (s, 9H), 3.10 (s, 1.5H), 3.11 (s, 1.5H),
3.60 (s, 1H), 7.24–7.32 (m, 3H), 7.44 (br, 1H), 7.62–7.66 (m, 2H);
13C NMR (CDCl3) ꢀ 28.72, 32.99, 35.67, 72.63, 127.40, 127.98,
130.39, 138.26, 206.07; Anal. Found: C, 70.62; H, 8.51%. Calcd
for C13H19NS: C, 70.54; H, 8.65%; mp 141–142 ꢂC.
O-{(E)-1-[Methyl(p-tolylsulfonyl)amino]-2-phenylethenyl}
Thiobenzoate ((E)-10): IR (nujol) 2924, 2854, 1349, 1264,
1162, 1048, 1027, 990, 686 cmꢁ1
Cyclohexylethynyl Dodecyl Sulfide (12h): IR (neat) 2927,
2854, 1448, 1361, 1296, 1232, 974, 888, 721 cmꢁ1 1H NMR
;
;
1H NMR (CDCl3) ꢀ 2.28 (s,
3H), 3.10 (s, 3H), 6.26 (s, 1H), 7.02 (d, J ¼ 8:0 Hz, 2H), 7.30–
7.40 (m, 5H), 7.55–7.60 (m, 3H), 7.62–7.68 (m, 2H), 7.88–8.04
(m, 2H); 13C NMR (CDCl3) ꢀ 21.63, 37.51, 119.74, 127.77,
128.23, 128.60, 128.82, 128.85, 129.52, 129.61, 131.83, 133.58,
136.17, 137.30, 142.55, 143.99, 209.53; Anal. Found: C, 65.17;
H, 5.15%. Calcd for C23H21NO3S2: C, 65.22; H, 5.00%; mp
138–140 ꢂC.
(CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz, 3H), 1.20–1.52 (m, 24H), 1.64–
1.83 (m, 6H), 2.45–2.55 (m, 1H), 2.66 (t, J ¼ 7:5 Hz, 2H);
13C NMR (CDCl3) ꢀ 14.08, 22.66, 24.78, 25.86, 28.23, 29.10,
29.13, 29.33, 29.46, 29.57, 29.61, 29.64, 30.37, 31.90, 32.71,
35.51, 68.31, 98.15. Anal. Found: C, 77.85; H, 12.02%. Calcd
for C20H36S: C, 77.85; H, 11.76%.
Dodecyl 3,3-Dimethyl-1-butynyl Sulfide (12i):
IR (neat)

512 Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
Hydrothiolation of Electron-Rich Alkynes
2967, 2926, 2855, 1458, 1362, 1252, 1203, 722 cmꢁ1
;
1H NMR
1.20–1.36 (m, 6H), 1.40–1.48 (m, 2H), 2.33 (s, 3H), 2.39–2.46 (m,
2H), 6.65–6.71 (m, 1H), 7.00 (dd, J ¼ 2:0, 7.5 Hz, 2H), 7.07 (d,
J ¼ 7:5 Hz, 2H), 7.37–7.43 (m, 4H), 7.45–7.51 (m, 2H), 7.84–
7.90 (m, 4H); 13C NMR (CDCl3) ꢀ 14.06, 21.03, 22.53, 28.81,
28.85 (d, J ¼ 8:0 Hz), 31.53, 32.12 (d, J ¼ 4:0 Hz), 121.45 (d,
J ¼ 7:1 Hz), 121.47 (d, J ¼ 7:6 Hz), 128.25 (d, J ¼ 13:4 Hz),
129.56, 131.08, 131.65 (d, J ¼ 2:9 Hz), 131.79 (d, J ¼ 11:0 Hz),
133.78 (d, J ¼ 83:6 Hz), 136.40, 156.27 (d, J ¼ 6:6 Hz); 31P NMR
(CDCl3) ꢀ 63.68. Anal. Found: C, 67.09; H, 6.43%. Calcd for
C27H31PS3: C, 67.18; H, 6.47%.
(CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz, 3H), 1.22 (s, 9H), 1.23–1.33 (m,
16H), 1.34–1.44 (m, 2H), 1.70 (tt, J ¼ 7:0, 7.5 Hz, 2H), 2.64 (t,
J ¼ 7:5 Hz, 2H); 13C NMR (CDCl3) ꢀ 14.09, 22.67, 28.22, 28.69,
29.01, 29.14, 29.33, 29.46, 29.58, 29.62, 29.65, 31.00, 31.90,
35.49, 67.05, 102.08. Anal. Found: C, 76.54; H, 12.26%. Calcd
for C18H34S: C, 76.52; H, 12.13%.
Dodecyl Ethynyl Sulfide (12j): IR (neat) 3309, 2925, 2854,
1
2044, 1466, 1061, 722, 666, 530 cmꢁ1; H NMR (CDCl3) ꢀ 0.88
(t, J ¼ 7:0 Hz, 3H), 1.20–1.35 (m, 16H), 1.36–1.44 (m, 2H), 1.74
(tt, J ¼ 7:0, 7.5 Hz, 2H), 2.73 (t, J ¼ 7:5 Hz, 2H), 2.74 (s, 1H);
13C NMR (CDCl3) ꢀ 14.10, 22.68, 28.22, 29.07, 29.14, 29.33,
29.46, 29.56, 29.62, 29.63, 31.91, 35.11, 74.76, 81.69. Anal.
Found: C, 74.21; H, 11.74%. Calcd for C14H26S: C, 74.26; H,
11.57%.
(E)-1-Dodecylsulfanyl-2-p-methoxyphenylethenyl Diphenyl-
dithiophosphinate (13e): IR (neat) 2925, 2853, 1605, 1506,
;
1437, 1252, 1177, 1097, 1034, 722 cmꢁ1 1H NMR (CDCl3) ꢀ
0.90 (t, J ¼ 7:0 Hz, 3H), 1.14–1.36 (m, 18H), 1.40–1.48 (m, 2H),
2.72 (t, J ¼ 7:5 Hz, 2H), 3.80 (s, 3H), 6.85 (d, J ¼ 9:0 Hz, 2H),
7.08 (d, J ¼ 3:5 Hz, 1H), 7.44–7.54 (m, 8H), 8.00–8.06 (m, 4H);
13C NMR (CDCl3) ꢀ 14.06, 22.61, 28.61, 29.06, 29.27, 29.32,
29.38, 29.48, 29.55, 29.57, 31.83, 34.32, 55.15, 113.30, 121.79
(d, J ¼ 8:1 Hz), 128.35 (d, J ¼ 13:4 Hz), 128.60 (d, J ¼ 2:9 Hz),
131.28 (d, J ¼ 1:4 Hz), 131.80 (d, J ¼ 11:0 Hz), 131.80 (d, J ¼
3:3 Hz), 133.86 (d, J ¼ 82:6 Hz), 146.08 (d, J ¼ 7:6 Hz), 159.37;
31P NMR (CDCl3) ꢀ 63.40. Anal. Found: C, 67.81; H, 7.44%.
Calcd for C33H43OPS3: C, 68.00; H, 7.44%.
(E)-1-Dodecylsulfanyl-2-o-methoxyphenylethenyl Diphenyl-
dithiophosphinate (13f): IR (neat) 3056, 2924, 2853, 1597,
1481, 1464, 1436, 1247, 1097, 748, 720, 690, 654 cmꢁ1; 1H NMR
(CDCl3) ꢀ 0.90 (t, J ¼ 7:0 Hz, 3H), 1.14–1.32 (m, 18H), 1.36–
1.44 (m, 2H), 2.67 (t, J ¼ 7:5 Hz, 2H), 3.76 (s, 3H), 6.82 (d,
J ¼ 7:5 Hz, 1H), 6.91 (dd, J ¼ 7:5, 7.5 Hz, 1H), 7.22–7.27 (m,
1H), 7.35 (d, J ¼ 4:0 Hz, 1H), 7.44–7.54 (m, 6H), 7.60 (d, J ¼
7:5 Hz, 1H), 8.01–8.08 (m, 4H); 13C NMR (CDCl3) ꢀ 14.07,
22.63, 28.63, 29.09, 29.12, 29.29, 29.40, 29.51, 29.57, 29.59,
31.85, 34.19, 55.37, 110.16, 119.71, 124.77 (d, J ¼ 8:1 Hz),
124.84 (d, J ¼ 2:4 Hz), 128.35 (d, J ¼ 13:4 Hz), 129.63, 130.66
(d, J ¼ 1:9 Hz), 131.76 (d, J ¼ 2:9 Hz), 131.86 (d, J ¼ 11:0 Hz),
133.94 (d, J ¼ 83:0 Hz), 141.30 (d, J ¼ 7:6 Hz), 156.90 (d, J ¼
0:9 Hz); 31P NMR (CDCl3) ꢀ 63.16. Anal. Found: C, 68.03; H,
7.31%. Calcd for C33H43OPS3: C, 68.00; H, 7.44%.
(E)-1-Dodecylsulfanyl-2-p-(trifluoromethyl)phenylethenyl
Diphenyldithiophosphinate (13g): IR (neat) 2926, 2854, 1437,
1324, 1167, 1126, 1068, 908, 722 cmꢁ1; 1H NMR (CDCl3) ꢀ 0.91
(t, J ¼ 7:5 Hz, 3H), 1.16–1.36 (m, 18H), 1.42–1.50 (m, 2H), 2.75
(t, J ¼ 7:5 Hz, 2H), 7.14 (d, J ¼ 3:0 Hz, 1H), 7.44–7.62 (m, 10H),
8.00–8.08 (m, 4H); 13C NMR (CDCl3) ꢀ 14.04, 22.60, 28.54,
29.02, 29.26, 29.36 (ꢃ2), 29.46, 29.54, 29.55, 31.82, 34.48,
123.96 (q, J ¼ 270:5 Hz), 124.83 (q, J ¼ 3:8 Hz), 128.44 (d,
J ¼ 4:8 Hz), 128.49 (d, J ¼ 8:1 Hz), 129.39 (d, J ¼ 32:5 Hz),
129.65 (d, J ¼ 1:4 Hz), 131.77 (d, J ¼ 10:9 Hz), 132.00 (d,
J ¼ 2:9 Hz), 133.62 (d, J ¼ 83:5 Hz), 139.15 (d, J ¼ 1:0 Hz),
143.17 (d, J ¼ 7:6 Hz); 31P NMR (CDCl3) ꢀ 63.87. Anal. Found:
C, 63.71; H, 6.47%. Calcd for C33H40F3PS3: C, 63.84; H, 6.49%.
(E)-2-Cyclohexyl-1-(dodecylsulfanyl)ethenyl Diphenyldi-
(E)-1-Dodecylsulfanyl-2-phenylethenyl Diphenyldithiophos-
phinate (13a): IR (neat) 3056, 2925, 2853, 1437, 1097, 925,
749, 721, 690, 655 cmꢁ1
;
1H NMR (CDCl3) ꢀ 0.90 (t, J ¼ 7:0
Hz, 3H), 1.14–1.34 (m, 18H), 1.38–1.46 (m, 2H), 2.71 (t, J ¼
8:0 Hz, 2H), 7.12 (d, J ¼ 3:5 Hz, 1H), 7.23–7.27 (m, 1H), 7.29–
7.34 (m, 2H), 7.45–7.56 (m, 8H), 8.00–8.07 (m, 4H); 13C NMR
(CDCl3) ꢀ 14.10, 22.65, 28.63, 29.09, 29.31, 29.36, 29.41, 29.51,
29.59, 29.60, 31.88, 34.40, 125.02 (d, J ¼ 8:1 Hz), 127.94,
128.07, 128.44 (d, J ¼ 13:4 Hz), 129.61 (d, J ¼ 1:5 Hz), 131.85
(d, J ¼ 10:9 Hz), 131.91 (d, J ¼ 3:4 Hz), 133.81 (d, J ¼ 83:0
Hz), 135.84 (d, J ¼ 2:9 Hz), 145.73 (d, J ¼ 7:6 Hz); 31P NMR
(CDCl3) ꢀ 63.45. Anal. Found: C, 69.64; H, 7.50%. Calcd for
C32H41PS3: C, 69.52; H, 7.47%.
(E)-2-Phenyl-1-p-tolylsulfanylethenyl Diphenyldithiophos-
phinate (13b):
IR (nujol) 2924, 2855, 1458, 1437, 1377,
1H NMR (CDCl3) ꢀ 2.31
1095, 928, 898, 813, 718, 652 cmꢁ1
;
(s, 3H), 7.02 (d, J ¼ 8:0 Hz, 2H), 7.07 (d, J ¼ 8:0 Hz, 2H),
7.22–7.34 (m, 3H), 7.36–7.42 (m, 4H), 7.46–7.52 (m, 3H), 7.57
(d, J ¼ 7:5 Hz, 2H), 7.80–7.94 (m, 4H); 13C NMR (CDCl3) ꢀ
21.11, 123.39 (d, J ¼ 8:1 Hz), 128.07, 128.35 (d, J ¼ 13:4 Hz),
128.71, 129.60 (d, J ¼ 1:4 Hz), 129.65, 130.43, 130.55, 131.80
(d, J ¼ 3:3 Hz), 131.87 (d, J ¼ 10:9 Hz), 133.67 (d, J ¼ 83:0
Hz), 135.53 (d, J ¼ 2:4 Hz), 137.06, 149.55 (d, J ¼ 7:1 Hz);
31P NMR (CDCl3) ꢀ 64.81. Anal. Found: C, 68.03; H, 5.03%.
Calcd for C27H23PS3: C, 68.32; H, 4.88%. mp 87.5–88.0 ꢂC. The
crystal data have been deposited at CCDC, Cambridge, UK and
given the reference number CCDC 670503. Copies of the data
can be obtained free of charge via http://www.ccdc.cam.ac.uk/
conts/retrieving.html (or from the Cambridge Crystallographic
Data Centre, 12, Union Road, Cambridge, CB2 1EZ, UK; Fax:
+44 1223 336033; e-mail: deposit@ccdc.cam.ac.uk).
(E)-1-Dodecylsulfanyl-1-octenyl Diphenyldithiophosphinate
IR (neat) 3056, 2924, 2854, 1457, 1437, 1097, 852,
1H NMR (CDCl3) ꢀ 0.88 (t, J ¼ 7:0
(13c):
748, 721, 690, 656 cmꢁ1
;
Hz, 6H), 1.18–1.45 (m, 28H), 2.25–2.33 (m, 2H), 2.60 (t,
J ¼ 7:5 Hz, 2H), 6.30 (dt, J ¼ 3:5, 7.5 Hz, 1H), 7.42–7.53 (m,
6H), 7.95–8.20 (m, 4H); 13C NMR (CDCl3) ꢀ 14.08 (ꢃ2),
22.55, 22.65, 28.60, 28.77 (d, J ¼ 2:4 Hz), 28.83, 29.17, 29.32,
29.49, 29.56 (ꢃ2), 29.61, 29.62, 31.61, 31.72 (d, J ¼ 1:9 Hz),
31.88, 33.41, 122.64 (d, J ¼ 7:6 Hz), 128.33 (d, J ¼ 13:4 Hz),
131.80 (d, J ¼ 11:0 Hz), 134.05 (d, J ¼ 83:1 Hz), 148.04 (d,
J ¼ 7:1 Hz), 152.70 (d, J ¼ 7:8 Hz); 31P NMR (CDCl3) ꢀ 62.34.
Anal. Found: C, 68.73; H, 8.72%. Calcd for C32H49PS3: C,
68.52; H, 8.80%.
thiophosphinate (13h):
IR (neat) 3056, 2925, 2852, 1956,
1899, 1810, 1437, 1097, 721, 690, 656 cmꢁ1; 1H NMR (CDCl3) ꢀ
0.89 (t, J ¼ 7:5 Hz, 3H), 1.00–1.34 (m, 23H), 1.36–1.46 (m, 2H),
1.56–1.70 (m, 5H), 2.56–2.66 (m, 3H), 6.17 (dd, J ¼ 3:5, 10.0 Hz,
1H), 7.41–7.52 (m, 6H), 7.95–8.02 (m, 4H); 13C NMR (CDCl3) ꢀ
14.05, 22.60, 25.37, 25.76, 28.53, 29.13, 29.26, 29.43, 29.45,
29.51, 29.54, 29.57, 31.83, 32.14 (d, J ¼ 2:4 Hz), 33.27, 40.70 (d,
J ¼ 0:9 Hz), 120.86 (d, J ¼ 7:6 Hz), 128.26 (d, J ¼ 13:4 Hz),
131.65 (d, J ¼ 2:9 Hz), 131.76 (d, J ¼ 11:0 Hz), 134.02 (d, J ¼
83:0 Hz), 157.86 (d, J ¼ 7:1 Hz); 31P NMR (CDCl3) ꢀ 62.13.
(E)-1-p-Tolylsulfanyl-1-octenyl Diphenyldithiophosphinate
(13d): IR (neat) 2954, 2925, 2855, 2370, 1491, 1437, 1097,
1
805, 721 655 cmꢁ1; H NMR (CDCl3) ꢀ 0.89 (t, J ¼ 7:0 Hz, 3H),

S. Kanemura et al.
Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
513
Anal. Found: C, 68.71; H, 8.51%. Calcd for C32H47PS3: C, 68.77;
H, 8.48%.
References
a) H. Kuniyasu, in Catalytic Heterofunctionalization, ed.
1
by A. Togni, H. Grutzmacher, Wiley-VCH, Weinheim, 2001,
(E)-1-Dodecylsulfanyl-3,3-dimethyl-1-butenyl Diphenyldi-
thiophosphinate (13i): IR (neat) 2956, 2925, 2854, 2360, 1458,
1437, 1362, 1202, 1097, 721, 690, 655 cmꢁ1; 1H NMR (CDCl3) ꢀ
0.89 (t, J ¼ 7:0 Hz, 3H), 1.13 (s, 9H), 1.20–1.34 (m, 18H), 1.40–
1.50 (m, 2H), 2.67 (t, J ¼ 8:0 Hz, 2H), 6.28 (d, J ¼ 4:0 Hz, 1H),
7.42–7.52 (m, 6H), 7.94–8.02 (m, 4H); 13C NMR (CDCl3) ꢀ
14.09, 22.64, 28.78, 29.15, 29.30, 29.47, 29.48, 29.54, 29.58,
29.60, 29.78 (d, J ¼ 1:9 Hz), 31.87, 33.95, 35.22 (d, J ¼ 1:4 Hz),
122.45 (d, J ¼ 7:3 Hz), 128.30 (d, J ¼ 13:4 Hz), 131.68 (d, J ¼
2:9 Hz), 131.84 (d, J ¼ 10:5 Hz), 134.03 (d, J ¼ 83:0 Hz), 161.41
(d, J ¼ 7:6 Hz); 31P NMR (CDCl3) ꢀ 62.54. Anal. Found: C,
67.66; H, 8.39%. Calcd for C30H45PS3: C, 67.62; H, 8.51%.
1-Dodecylsulfanylethenyl Diphenyldithiophosphinate (13j):
¨
Chap. 7. b) F. Alonso, I. P. Beletskaya, M. Yus, Chem. Rev.
2004, 104, 3079. c) C. Cao, L. R. Fraser, J. A. Love, J. Am. Chem.
Soc. 2005, 127, 17614, and references cited therein.
2
Reviews on the chemistry of N-(1-alkynyl)amides, so-
called ynamides: a) C. A. Zificsak, J. A. Mulder, R. P. Hsung,
C. Rameshkumar, L.-L. Wei, Tetrahedron 2001, 57, 7575.
b) J. A. Mulder, K. C. M. Kurtz, R. P. Hsung, Synlett 2003,
1379. c) B. Witulski, C. Alayrac, in Science of Synthesis, ed. by
A. de Meijere, Thieme, Stuttgart, 2005, Vol. 24, Chap. 24.4.4.2.
3
Brønsted acid-catalyzed addition reaction of allyl or prop-
argyl alcohol followed by Claisen rearrangement: a) J. A. Mulder,
R. P. Hsung, M. O. Frederick, M. R. Tracey, C. A. Zificsak,
Org. Lett. 2002, 4, 1383. b) M. O. Frederick, R. P. Hsung,
R. H. Lambeth, J. A. Mulder, M. P. Tracey, Org. Lett. 2003, 5,
2663. Hydrohalogenation: c) J. A. Mulder, K. C. M. Kurtz,
R. P. Hsung, H. Coverdale, M. O. Frederick, L. Shen, C. A.
Zificsak, Org. Lett. 2003, 5, 1547. Brønsted acid-catalyzed hydro-
arylation: d) Y. Zhang, Tetrahedron Lett. 2005, 46, 6483. e) Y.
Zhang, R. P. Hsung, X. Zhang, J. Huang, B. W. Slafer, A. Davis,
Org. Lett. 2005, 7, 1047. Lewis acid-catalyzed reaction with
carbonyl compounds: f) K. C. M. Kurtz, R. P. Hsung, Y.
Zhang, Org. Lett. 2006, 8, 231. g) L. You, Z. F. Al-Rashid, R.
Figueroa, S. K. Ghosh, G. Li, T. Lu, R. P. Hsung, Synlett 2007,
1656.
IR (neat) 2924, 2853, 1576, 1436, 1309, 1096, 723, 690 cmꢁ1
;
1H NMR (CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz, 3H), 1.18–1.38 (m, 18H),
1.42–1.47 (m, 2H), 2.64 (t, J ¼ 7:5 Hz, 2H), 5.56 (dd, J ¼ 1:5,
3.5 Hz, 1H), 5.69 (dd, J ¼ 1:5, 3.5 Hz, 1H), 7.38–7.58 (m, 6H),
7.96–8.02 (m, 4H); 13C NMR (CDCl3) ꢀ 14.09, 22.65, 27.99,
28.78, 29.07, 29.31, 29.43, 29.53, 29.59, 29.61, 31.88, 34.15,
123.66 (d, J ¼ 7:3 Hz), 128.42 (d, J ¼ 13:4 Hz), 131.87 (d, J ¼
11:0 Hz), 131.93 (d, J ¼ 2:4 Hz), 133.06 (d, J ¼ 6:8 Hz), 133.68
(d, J ¼ 84:0 Hz); 31P NMR (CDCl3) ꢀ 62.81. Anal. Found: C,
65.64; H, 7.90%. Calcd for C26H37PS3: C, 65.50; H, 7.82%.
Dodecyl Phenylethanedithioate (14): IR (neat) 2925, 2854,
2370, 1453, 1219, 1131, 991, 858, 697 cmꢁ1 1H NMR (CDCl3)
;
ꢀ 0.89 (t, J ¼ 7:0 Hz, 3H), 1.22–1.33 (m, 16H), 1.34–1.41 (m,
2H), 1.61–1.69 (m, 2H), 3.18 (t, J ¼ 7:5 Hz, 2H), 4.31 (s, 2H),
7.25–7.38 (m, 5H); 13C NMR (CDCl3) ꢀ 14.10, 22.67, 27.12,
29.04, 29.09, 29.32, 29.40, 29.52, 29.60, 29.61, 31.89, 37.03,
58.13, 127.17, 128.49, 129.03, 137.09, 235.81. Anal. Found: C,
71.65; H, 9.62%. Calcd for C20H32S2: C, 71.37; H, 9.58%.
Dodecyl (E)-2-Phenyl-1-(phenylsulfanyl)ethenyl Sulfide
(15a): IR (neat) 3068, 2925, 2853, 2360, 1950, 1582, 1440, 1024,
4
A review on the chemistry of 1-alkynyl sulfides: V. A.
Potapov, B. A. Trofimov, in Science of Synthesis, ed. by A. de
Meijere, Thieme, Stuttgart, 2005, Vol. 24, Chap. 24.4.3.
5
Addition to 1-alkynyl sulfides under acidic conditions:
a) F. Manarin, J. A. Roehrs, M. Prigol, D. Alves, C. W. Nogueira,
G. Zeni, Tetrahedron Lett. 2007, 48, 4805. b) A. L. Braga, D. J.
Emmerich, C. C. Silveira, T. L. C. Martins, O. E. D. Rodrigues,
Synlett 2001, 371.
6
Thieme, Stuttgart, 2005, Vol. 24, Chap. 24.2.11; 2005, Vol. 24,
739, 690 cmꢁ1
;
1H NMR (CDCl3) ꢀ 0.88 (t, J ¼ 7:0 Hz, 3H),
W. Dolling, in Science of Synthesis, ed. by A. de Meijere,
¨
1.14–1.40 (m, 18H), 1.48–1.55 (m, 2H), 2.79 (t, J ¼ 7:5 Hz, 2H),
7.11 (s, 1H), 7.22–7.38 (m, 6H), 7.41–7.46 (m, 2H), 7.62–7.66 (m,
2H); 13C NMR (CDCl3) ꢀ 14.10, 22.68, 28.64, 29.07, 29.34,
29.44, 29.54, 29.62, 29.63, 29.65, 31.91, 33.80, 127.01, 127.58,
128.07, 129.02, 129.52, 130.15, 131.71, 135.20, 136.20, 137.51.
Anal. Found: C, 75.63; H, 8.96%. Calcd for C26H36S2: C, 75.67;
H, 8.79%.
Chap. 24.2.13.
7
This work was communicated: H. Yasui, H. Yorimitsu, K.
Oshima, Chem. Lett. 2008, 37, 40.
Syn addition to ynamides under Brønsted acid catalysis
was reported in Ref. 3d.
G. Peters, J. Org. Chem. 1962, 27, 2198.
8
9
t
(Z)-1-Butylsulfanyl-2-phenylethenyl Dodecyl Sulfide (15b):
IR (neat) 2956, 2925, 2854, 1560, 1491, 1466, 928, 750, 691
10 Treatment of 3a with 2.2 molar amount of BuLi under
similar conditions provided 8 in 44% 1H NMR yield along with
the recovery of 3c in 33% 31P NMR yield. The reason why 4.0
1
cmꢁ1; H NMR (CDCl3) ꢀ 0.89 (t, J ¼ 7:0 Hz, 3H), 0.95 (t, J ¼
t
7:0 Hz, 3H), 1.18–1.51 (m, 20H), 1.52–1.59 (m, 2H), 1.60–1.69
(m, 2H), 2.82 (t, J ¼ 6:0 Hz, 2H), 2.83 (t, J ¼ 7:0 Hz, 2H), 6.99
(s, 1H), 7.21–7.60 (m, 1H), 7.31–7.36 (m, 2H), 7.60–7.65 (m,
2H); 13C NMR (CDCl3) ꢀ 13.70, 14.10, 21.93, 22.68, 28.69,
29.14, 29.34 (ꢃ2), 29.47, 29.55, 29.63, 29.69, 31.16, 31.90, 33.28,
33.87, 127.12, 127.98, 129.31, 132.97, 134.32, 136.56. Anal.
Found: C, 73.55; H, 10.44%. Calcd for C24H40S2: C, 73.40; H,
10.27%.
molar amount of BuLi was needed is not clear.
11 a) K. Goda, N. Inamoto, Chem. Lett. 1975, 1009. b) K.
Goda, R. Okazaki, K. Akiba, N. Inamoto, Tetrahedron Lett.
1976, 17, 181. c) K. Goda, R. Okazaki, K. Akiba, N. Inamoto,
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N. Inamoto, Bull. Chem. Soc. Jpn. 1978, 51, 818.
12 pKa (Ph2P(=S)SH, in 80% alcohol) = 2.6: a) M. I.
Kabachnik, T. A. Mastrukova, A. E. Shipov, T. A. Melentyeva,
Tetrahedron 1960, 9, 10. pKa (PhC(=O)SH, in DMSO) = 5.2,
pKa (PhSH, in DMSO) = 9.8: b) J. Courtot-Coupez, M. Le
Demezet, Bull. Soc. Chim. Fr. 1969, 1033.
13 T. B. Clark, K. A. Woerpel, Organometallics 2005, 24,
6212.
14 Y. Zhang, R. P. Hsung, M. R. Tracey, K. C. M. Kurtz, E. L.
Vera, Org. Lett. 2004, 6, 1151.
This work was supported by Grants-in-Aid for Scientific
Research and COE Research from the Ministry of Education,
Culture, Sports, Science and Technology, Japan. A.K. ac-
knowledges JSPS for financial support. We thank Prof. Masaki
Shimizu (Kyoto University) for helping with the X-ray crystal-
lographic analysis.
´
´

514 Bull. Chem. Soc. Jpn. Vol. 81, No. 4 (2008)
Hydrothiolation of Electron-Rich Alkynes
dodecanethiol was difficult.
17 N. Riddel, W. Tam, J. Org. Chem. 2006, 71, 1934.
18 P. Zhong, M.-P. Guo, N.-P. Huang, Synth. Commun. 2002,
32, 175.
15 W. A. Higgins, P. W. Vogel, W. G. Craig, J. Am. Chem.
Soc. 1955, 77, 1864.
16 This operation converted dodecylthiolithium to 2-dodec-
ylthioethanol. Without this, separation of the product 12 and