(Alk-1-ynyl)organylthiocarbenes: Generation and reactions with olefins

Article abstract of DOI:10.1007/s11172-005-0152-4

1-Substituted 1-chloro-3-organylthiopropa-1,2-dienes 1a-f belonging to previously unknown type of allenic compounds were synthesized by chlorination of 1-organylthioalk-1-ynes 3a-f with N-chlorosuccinimide. The reactions of compounds 1a-f with Bu^t

Full text of DOI:10.1007/s11172-005-0152-4

2546
Russian Chemical Bulletin, International Edition, Vol. 53, No. 11, pp. 2546—2553, November, 2004
(Alkꢀ1ꢀynyl)organylthiocarbenes:
generation and reactions with olefins*
K. N. Shavrin,a V. D. Gvozdev,a I. Yu. Pinus,b I. P. Dotsenko,b and O. M. Nefedova
ꢀ
aN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (095) 135 5328. Eꢀmail: nefedov@ioc.ac.ru
bHigher Chemical College of the Russian Academy of Sciences,
9 Miusskaya pl., 125820 Moscow, Russian Federation
1ꢀSubstituted 1ꢀchloroꢀ3ꢀorganylthiopropaꢀ1,2ꢀdienes 1a—f belonging to previously unꢀ
known type of allenic compounds were synthesized by chlorination of 1ꢀorganylthioalkꢀ1ꢀynes
3a—f with Nꢀchlorosuccinimide. The reactions of compounds 1a—f with ButOK in hexane
at –20 °C are accompanied by γꢀelimination of HCl to give new alkꢀ1ꢀynyl(organylthio)carbenes
2a—f, which add to olefins to form the corresponding 1ꢀ(alkꢀ1ꢀynyl)ꢀ1ꢀorganylthioꢀ
cyclopropanes 5 in yields of up to 60%. The electrophilic properties of carbenes 2 were
confirmed experimentally.
Key words: 1ꢀsubstituted 1ꢀchloroꢀ3ꢀorganylthiopropaꢀ1,2ꢀdienes, alkynꢀ1ꢀyl(organylꢀ
thio)carbenes, 1ꢀ(alkynꢀ1ꢀyl)ꢀ1ꢀorganylthiocyclopropanes, [1+2] cycloaddition, electrophilic
carbenes.
Scheme 1
A wide range of (alkꢀ1ꢀynyl)carbenes containing variꢀ
ous substituents at the carbene center,2—11 including (alkꢀ
1ꢀynyl)halocarbenes,4—7,9 (alkꢀ1ꢀynyl)hetarylcarbenes,10
and 4ꢀmethylpentꢀ3ꢀenꢀ1ꢀynyl(methoxycarbonyl)carꢀ
bene,11 have been generated using various methods. In
the present study, we examined the reactions of 1ꢀsubstiꢀ
tuted 1ꢀchloroꢀ3ꢀorganylthiopropaꢀ1,2ꢀdienes 1 with
ButOK yielding previously unknown alkꢀ1ꢀynyl(organylꢀ
thio)carbenes 2. In the presence of olefins, the latter comꢀ
pounds give the corresponding 1ꢀ(alkꢀ1ꢀynyl)ꢀ1ꢀorganylꢀ
thiocyclopropanes.
Starting chlorosulfides 1a—f were prepared by chloriꢀ
nation of 1ꢀorganylthioalkꢀ2ꢀynes 3a—f with Nꢀchloroꢀ
succinimide (NCS). The reaction was carried out by stirꢀ
ring equimolar amounts of the reagents in CCl4 at 20 °C
for 1—10 h. It should be noted that the reactions of sulꢀ
fides 3c—f gave chloroallenes 1c—f, whereas compounds
3a,b gave (according to the NMR spectroscopic data)
mixtures of isomeric allenes 1a,b and acetylenes 4a,b
(Scheme 1) in ratios of 1 : 1 and 1 : 3, respectively.
The NMR monitoring of these mixtures in CDCl3
demonstrated that acetylenes 4a,b undergo isomerization
to the corresponding allenes 1a,b at room temperature.
The rate of this process depends substantially on the strucꢀ
tures of compounds 4a,b. For example, the rearrangeꢀ
ment of 4a into 1a was completed in several hours, whereas
acetylene 4b was completely transformed into allene 4b
Compound
1a, 3a, 4a
1b, 3b, 4b
1c, 3c
1d, 3d
1e, 3e
R1
But
Ph
But
But
But
Ad
H
R2
Ph
Me
Me
pꢀTol
Bun
Me
Bun
1f, 3f
1g, 3g
Reagent and conditions: i. NCS, CCl4, 20 °C; ii. CDCl3, 20 °C.
already during 15 min. These data indicate that the reacꢀ
tions of sulfides 3a—f with NCS involve chlorination at
the α position with respect to the sulfur atom to form
acetylenes 4, which undergo acetylene—allene isomerꢀ
* For the preliminary communication, see Ref. 1.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2440—2447, November, 2004.
1066ꢀ5285/04/5311ꢀ2546 © 2004 Springer Science+Business Media, Inc.

(Alkꢀ1ꢀynyl)organylthiocarbenes
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004 2547
ization to give compound 1. This reaction scheme is conꢀ
sistent with the published data on diorganyl sulfides.12
The structures of allenes 1a—f were established by 1H
and 13C NMR spectroscopy (Table 1). In particular, the
13C NMR spectra show signals at δ 94—123 and 192—197
characteristic of the terminal and central carbon atoms of
butyl propargyl sulfide (3g) containing the hydrogen atom
at the triple bond. This reaction afforded 3ꢀbutylthioꢀ1ꢀ
chloropropadiene (1g) as the major product. The 1H NMR
spectrum of this product has an AB system with the spinꢀ
spin coupling constant of 5.5 Hz at δ 6.3 corresponding to
two nonequivalent allenic protons. The 13C NMR specꢀ
trum of compound 1g shows two signals for the sp2ꢀhybriꢀ
dized carbon atoms at δ 94.3 and 101.3 assigned (accordꢀ
ing to the results of DEPT experiments) to two CH groups.
These results reliably prove the structure of allene 1g and
provide evidence for the formation of allenes 1 as a result
of migration of the chlorine atom in the initially formed
acetylenes 4.
1
the allenic fragment, respectively. The H NMR spectra
have a singlet at δ 6.2—6.7 corresponding to the proton at
the double bond. However, the spectroscopic data did not
allow us to unambiguously determine whether the chloꢀ
rine atom and the organylthio group in allenes 1a—f are
located at the same or different carbon atoms. To solve
this problem, we carried out the reaction of NCS with
Table 1. The 1H NMR (CDCl3, 200.13 MHz) and 13C NMR (CDCl3, 50 MHz) spectra of allenes 1a—g
Comꢀ
pound
1H NMR (δ, J/Hz)
13C NMR (δ)
R2
R1
—СH=
R1
R2
C=C=C
1a
1b
1c
1d
7.30—7.55
(m, 5 H, Ph)
0.98 (s,
9 Н, 3 Me)
6.29 (s, 1 H)
28.1 (3 Me);
37.2 (CMe3)
129.4; 133.3; 134.6 (Ph);
131.6 (C(1), Ph)
98.5 (CH=);
122.1 (CCl=);
194.4 (=C=)
102.5 (CH=);
112.4 (CCl=);
195.8 (=C=)
99.6 (CH=);
122.9 (CCl=);
192.5 (=C=)
99.1 (CH=);
121.8 (CCl=);
2.23 (s,
3 H, Me)
7.20—7.50
(m, 5 Н, Ph)
6.67 (s, 1 H)
6.23 (s, 1 H)
6.28 (s, 1 H)
126.4, 128.3,
128.5 (Ph);
133.8 (C(1))
28.6 (3 Me);
37.5 (CMe3)
13.8 (Me)
14.2 (Me)
2.15 (s,
3 H, Me)
1.17 (s,
9 Н, 3 Me)
2.38 (s,
0.98 (s,
9 Н, 3 Me)
28.0 (3 Me);
37.1 (CMe3)
21.0 (Me); 127.7 (C(4));
129.3, 133.5 (C(2), C(3),
C(5), C(6)); 138.5 (C(1)) 193.9 (=C=)
3 H, Me);
7.19 (br.d,
2 H, 2 CH,
J = 7.5);
7.38 (br.d,
2 H, 2 CH,
J = 7.5)
1e
0.95 (t,
3 Н, Me,
J = 7.7);
1.19 (s,
9 Н, 3 Me)
6.19 (s, 1 H)
28.5 (3 Me);
37.4 (CMe3)
13.6 (Me); 22.1, 31.2,
31.3 (3 CH2)
98.5 (CH=);
121.9 (CCl=);
192.7 (=C=)
1.35—1.65
(m, 4 Н,
2 СН2); 2.62
(br.t, 2 Н,
СH2S, J = 7.2)
2.11 (s,
1f
1.10—1.25
(m, 12 Н,
6 СН2);
6.21 (s, 1 H)
28.2 (3 CH);
36.4 (3 CH2);
40.6 (3 CH2)
14.1 (Me)
99.7 (CH=);
122.7 (CCl=);
192.6 (=C=)
3 H, Me)
1.95—2.05
(m, 3 Н, 3 СН)
1g
0.92 (t,
6.30, 6.33 (both d, 1 H each,
CH, J = 5.5)
—
13.6 (Me); 22.0, 30.4,
31.4 (3 CH2)
94.3 (CH=);
101.3 (CH=);
197.3 (=C=)
3 Н, Me,
J = 7.7);
1.30—1.65
(m, 4 Н,
2 СН2);
2.62 (br.t,
2 Н, СH2S,
J = 7.2)

2548
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004
Shavrin et al.
It should be noted that the formation of allenes 1 was
observed in the reactions with compounds, in which the
substituent at the triple bond (R1) contains no hydrogen
atoms at the α position. Otherwise, the reactions afforded
complex mixtures of products, in which the expected
allene 1 was absent (example is the reaction of hexꢀ2ꢀynyl
methyl sulfide with NCS).
followed by elimination of Cl– giving rise to carbenes
7a—f (analogously to the generation of (alkꢀ1ꢀynyl)haloꢀ
carbenes from 3ꢀsubstituted 1,1ꢀdichloropropadienes7).
However, carbenes 7 undergo rapid propargylic isomerꢀ
ization to thermodynamically more stable carbenes 2a—f.
Actually, the reactions in the presence of an excess of
olefins did not gave carbene adducts 7, whereas the yields
of carbene adducts 2 (cyclopropanes 5) were 12—54%.
The reactivity of carbenes 2 with respect to olefins
depends substantially on both the structure of the latter
and the nature of the organylthio group. For example, the
generation of carbenes 2c and 2f containing the methylthio
group at the carbene center in the presence of 2,3ꢀdiꢀ
methylbutꢀ2ꢀene afforded the corresponding cycloproꢀ
pane adducts in 28—39% yields. The reactions with less
nucleophilic 2ꢀmethylpropene instead of the aboveꢀmenꢀ
tioned alkene did not give cyclopropanation products.
The replacement of the alkylthio group at the carbene
center with the arylthio group not only leads to an inꢀ
crease in the yields of cyclopropane products but also
extends the spectrum of alkenes, which can be successꢀ
fully involved in cycloaddition (see Scheme 2, Table 2).
Only one of the possible isomers of cyclopropane 5g
was detected by GLC and NMR spectroscopy among
the products prepared by the reaction with the use
of 2ꢀmethylbutꢀ2ꢀene for trapping the corresponding
carbene 2d. However, the spectroscopic data for comꢀ
pound 5g did not allow us to establish the relative arꢀ
rangement of the substituents. This unusual stereoꢀ
selectivity is, apparently, attributable to steric factors asꢀ
Allenes 1 are unstable and rapidly resinify during storꢀ
age without a solvent at room temperature (in the case of
compounds 1b and 1g, resinification occurs within sevꢀ
eral hours, other compounds resinify in a matter of days).
As a result, we failed to purify these compounds by vacuum
distillation and, hence, used them immediately after filꢀ
tering off succinimide that formed in the course of their
synthesis and removing the solvent under vacuum.
Treatment of chloro sulfides 1a—f with ButOK in hexꢀ
ane at –20 °C in the presence of alkenes afforded the corꢀ
responding 1ꢀ(alkꢀ1ꢀynyl)ꢀ1ꢀorganylthiocyclopropanes
5a—j in yields of up to 60%, which indicates that previꢀ
ously unknown alkꢀ1ꢀynyl(organylthio)carbenes 2a—f are
generated under these conditions (Scheme 2, Table 2).
Quantumꢀchemical calculations13 have demonstrated
that the energetically most favorable pathway of formaꢀ
tion of carbenes 2 upon the proton abstraction from
allenes 1 involves the simultaneous cleavage of the C—Cl
bond and migration of the carbene center to the carbon
atom bound to the organylthio group. It cannot also be
ruled out that these reactions proceed according to an
alternative scheme involving deprotonation of allenes
1a—f under the action of ButOK to form anions 6a—f
Scheme 2
1, 2, 6, 7: R1 = But (a, c—e), Ph (b), Ad (f); R2 = Ph (a), Me (b, c, f), pꢀTol (d), Bun (e); 5: R1 = But (a—h), Ad (i), Ph (j)
5
R2
R3
R4
R5
R6
5
R2
R3
R4
R5
R6
a
b
c
d
e
Me
Me
Ph
Ph
pꢀTol
Me
Ph
Me
Me
Me
Me
H
Me
Me
Me
Me
H
Me
H
Me
H
Me
H
f
g
h
i
pꢀTol
pꢀTol
Bun
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
H
Me
Me
Me
H
Me
Me
Me
Me
Me
Me
j

(Alkꢀ1ꢀynyl)organylthiocarbenes
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004 2549
Table 2. Reactions of 1ꢀsubstituted 1ꢀchloroꢀ3ꢀorganylthiopropadienes 1a—f with ButOK in the presence of alkenes
Carbene
source
Carbene
Alkene
Product
Yielda
B.p./°Cb
(p/Torr)
Found
Calculated
Molecular
formula
(%)
R3
R4
R5
R6
С
H
1a
1a
1b
1c
1c
1c
1d
1d
1d
1e
1f
2a
2a
2b
2c
2c
2c
2d
2d
2d
2e
2f
Me
H
Me
Me
Me
Me
H
Me
Me
Me
Me
H
Me
H
5c
5d
5j
38
49
12
28
18
—
50
54
57
31
39
—
130—140 (1)c
105—107 (1)
120—130 (1)c
80—100 (2)c
150—160 (1)c
—
79.31
79.66
79.25
79.01
78.91
78.63
9.02 C19H26S
9.15
8.76 C17H22S
8.58
8.41 C16H20S
8.25
Me
Me
Ph
H
Me
Me
H
5a
74.68 10.96 C14H24S
74.93 10.78
78.42
78.63
transꢀ : cisꢀ5b =
8.33 C16H20S
8.25
= 5 : 1
c
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
—
Me
H
Me
H
5e
5f
160—170 (1)c
120—135 (1)c
130—140 (1)c
110—120 (1)c
180—195 (1)c
—
79.83
79.94
79.58
79.35
79.32
79.66
9.13 C20H28S
9.39
8.97 C18H24S
8.88
9.29 C19H26S
9.15
Me
Me
Me
H
H
5g
5h
5i
Me
Me
H
76.68 11.14 C14H24S
76.62 11.35
79.19
9.81 C20H30S
79.41 10.00
c
1f
2f
—
a The yield of the product is given taking into account the purity of the starting chloroallene.
b The temperature of the bath used for vacuum microdistillation.
c A cyclopropanation product was not detected.
sociated with the presence of a bulky arylthio group. In
the resulting isomer, the proton and the paraꢀtolylthio
group are, most likely, located on the same side of the
plane of the cyclopropane ring.
assigned to the cis and trans isomers of 5b based on comꢀ
parison of the integral intensities of these signals.
The reaction with the use of 2ꢀmethylbutaꢀ1,3ꢀdiene
for trapping (3,3ꢀdimethylbutꢀ1ꢀynyl)phenylthiocarbene
(2a), followed by treatment of the reaction mixture with
water and removal of the solvent, afforded a residue conꢀ
sisting of cyclopropane 8a and cycloheptatriene 9 in a
ratio of 1 : 0.8 (Scheme 3), as evident from NMR spectroꢀ
scopic data. We succeeded in isolating a mixture of these
two products by vacuum microdistillation. The total yield
was 47%.
The formation of compound 9 with a cycloheptatriene
structure and only one of the possible geometric isomers
of cyclopropane 8 can be explained as follows. Initially,
carbene 2a adds at the more substituted double bond of
2ꢀmethylbutaꢀ1,3ꢀdiene to form two isomeric cycloproꢀ
panes 8a and 8b, and then cyclopropane 8b with a cis arꢀ
rangement of the vinyl and alkynyl groups undergoes
isomerization accompanied by the opening of the threeꢀ
membered ring to give triene 9. Analogous transformaꢀ
tions of cyclopropanes containing two unsaturated vicinal
substituents in the cisꢀconfiguration have been described
in the literature. For example, cisꢀ1,2ꢀdivinylcycloꢀ
The structures of cyclopropanes 5a—j were established
1
by elemental analysis, GLCꢀmass spectrometry, and H
and 13C NMR spectroscopy (Tables 3 and 4). The
13C NMR spectra of these cyclopropanes show signals at
1
δ 75—91 characteristic of the triple bond. The H NMR
spectra have signals for the protons characteristic of the
corresponding substituents at the cyclopropane fragment,
the triple bond, and the sulfur atom.
The trans and cis isomers of cyclopropane 5b were
identified based on the chemical shifts for the protons of
the cyclopropane fragment at the C atom bearing the
phenyl group, on the assumption that the signals for the
protons of the substituents in the cis position with respect
to the methylthio group are shifted downfield due to the
deshielding effect of the latter group. For the major isoꢀ
mer, the signal for this proton is present at lower field
(δ 2.72) compared to the corresponding signal for the
minor isomer (δ 2.51) due to the deshielding effect of the
methylthio group. Other signals in the NMR spectra were

2550
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004
Shavrin et al.
Table 3. The 1H NMR spectra (CDCl3, 200.13 MHz) of (alkꢀ1ꢀynyl)organylthiocyclopropanes 5a—j
Comꢀ
pound
1H NMR (δ, J/Hz)
R1
R2
R3
R4
R5
R6
5a
1.21 (s, 9 H, But)
2.12 (s, 3 H, Me)
2.39 (s, 3 H, Me)
1.17 (s, 6 H, 2 Me); 1.19 (s, 6 H, Me)
transꢀ5b 1.31 (s, 9 H, But)
7.25—7.35
(m, 5 Н, Ph)
1.48 (dd, 1 H,
CH2, J1 = 5.3,
J2 = 7.5)
1.63 (dd, 1 H,
CH2, J1 = 5.3,
J2 = 8.6)
2.72 (dd, 1 H,
CH2, J1 = 7.5,
J2 = 8.6)
2.51 (dd, 1 H,
cisꢀ5b
1.26 (s, 9 H, But)
1.13 (s, 9 H, But)
2.41 (s, 3 H, Me)
7.25—7.35
(m, 5 Н, Ph)
1.20—1.39 (m, 2 H, CH2)
CH2, J1 = 6.3,
J2 = 9.1)
5c
7.15 (br.t, 1 H,
pꢀН, J = 7.1);
7.29 (br.t, 2 H,
mꢀН, J = 7.1);
7.40 (br.d, 2 H,
oꢀН, J = 7.1)
7.20 (br.t, 1 H,
pꢀН, J = 7.1);
7.33 (br.t, 2 H,
mꢀН, J = 7.1);
7.45 (br.d, 2 H,
oꢀН, J = 7.1)
1.28, 1.33 (both s, 6 H each, 2 Me)
5d
1.18 (s, 9 H, But)
1.16 (d,
1 H, J = 4.9)
1.39, 1.45 (both s, 3 H each, Me)
1.03 (d, 1 H,
J = 4.9)
5e
5f
1.19 (s, 9 H, But)
1.22 (s, 9 H, But)
1.22 (s, 9 H, But)
1.20 (s, 9 H, But)
2.37 (s, 3 H, Me);
7.12 (br.d, 2 H,
oꢀН, J = 8.3);
7.31 (br.d, 2 H,
mꢀН, J = 8.3)
2.39 (s, 3 H, Me); 1.13 (d,
7.17 (br.d, 2 H,
oꢀН, J = 8.3);
7.41 (br.d, 2 H,
1.30, 1.33 (both s, 6 H each, Me)
1.42, 1.47 (both s, 3 H each, Me)
1.25, 1.37 (both s, 3 H each, Me)
1.12, 1.14 (both s, 6 H each, Me)
1.02 (d, 1 H,
1 H, J = 4.8)
J = 4.8)
mꢀН, J = 8.3)
2.37 (s, 3 H, Me); R3 + R6: 1.05—
5g
5h
—
7.14 (br.d, 2 H,
oꢀН, J = 8.3);
7.34 (br.d, 2 H,
mꢀН, J = 8.3)
0.89 (t, 3 Н,
1.30 (m, 4 H,
CH, CHMe)
Me, J = 7.1);
1.30—1.60 (m,
4 Н, 2 СН2);
2.63 (t, 2 Н,
СH2S, J = 7.3)
2.13 (s, 3 H, Me)
5i
5j
1.67, 1.84
1.17, 1.18 (both s, 6 H each, Me)
1.30, 1.32 (both s, 6 H each, Me)
(both m, 6 H each,
3 CH2); 1.91
(m, 3 H, 3 CH)
7.30—7.50
2.28 (s, 3 H, Me)
(m, 5 H, Ph)
propanes readily undergo isomerization with the ring
opening to form the corresponding cycloheptadienes.14
The structures of products 8a and 9 were established
by 1H and 13C NMR spectroscopy without their isolation
from the mixture. These spectra were very complicated.
Hence, to make a reliable assignment of the signals and
determine the structures of 8a and 9, we used the homoꢀ
and heteronuclear double resonance techniques and
DEPT spectra.
The H NMR spectrum of compound 8a shows sinꢀ
glets of the tertꢀbutyl and methyl groups at δ 1.19 and 1.59,
1
respectively, an AB system with the spinꢀspin coupling

(Alkꢀ1ꢀynyl)organylthiocarbenes
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004 2551
Table 4. The 13C NMR spectra (CDCl3, 50.32 MHz) and mass spectra of (alkꢀ1ꢀynyl)organylthiocyclopropanes 5a—j
Comꢀ
pound
13C NMR (δ)
MS, m/z
C≡C
cycloꢀС3
R1
R2
R3—R
5a
77.7, 90.8 29.6 (2 CMe2); 34.3 (CSMe) 27.7 (CMe3); 31.5 (3 Me)
14.9 (Me)
15.8 (Me)
18.1, 20.2 (4 Me) 224 [M]+
transꢀ5b 81.0, 86.7 22.3 (CH2); 27.2 (CSMe);
28.5 (CMe3);
30.9 (3 Me)
126.5, 127.5,
128.9 (Ph);
244 [M]+
244 [M]+
34.1 (CHPh)
135.8 (C(1), Ph)
126.1, 127.3,
128.2 (Ph); 137.1
(C(1), Ph)
cisꢀ5b
75.2, 88.1 23.4 (CH2); 23.8 (CSMe);
35.2 (CHPh)
28.2 (CMe3); 31.0 (3 Me)
16.2 (Me)
5c
78.6, 90.1 30.6 (2 CMe2); 33.7 (CSMe) 27.6 (CMe3); 31.2 (3 Me)
124.8, 127.8, 18.8, 20.3
286 [M]+
128.3 (Ph);
137.3
(4 Me)
(Cipso, Ph)
5d
5e
80.1, 88.9 26.2 (CSPh); 27.5 (CMe2); 27.3 (CMe3); 31.1 (3 Me)
31.0 (CH2)
125.2, 128.0, 21.7, 23.9 (2 Me) 258 [M]+
128.4 (Ph);
137.1 (Cipso
21.1 (Me);
)
78.9, 90.9 30.6 (2 CMe2); 34.0 (CSMe) 27.7 (CMe3); 31.3 (3 Me)
18.8, 20.4 (4 Me) 300 [M]+
128.4, 129.1
(C(2), C(3),
C(5), C(6));
133.5, 134.7
(C(1), C(4))
20.9 (Me);
128.7, 129.1
(C(2), C(3),
C(5), C(6));
133.1, 135.1
(C(1), C(4))
21.0 (Me);
5f
80.3, 88.6 27.2 (CMe2); 27.3 (CSTol); 27.0 (CMe3); 31.1 (3 Me)
31.0 (CH2)
21.7, 23.9 (2 Me) 272 [M]+
5g
77.6, 91.4 29.2 (CMe2); 29.3 (CSTol)
27.5 (CMe3); 31.0 (3 Me)
10.2, 18.0, 23.4,
286 [M]+
128.3, 130.0 32.2 (3 Me + CH)
(C(2), C(3),
C(5), C(6));
133.7, 134.8
(C(1), C(4))
5h
77.7, 91.2 29.1 (2 CMe2); 33.2 (CSMe) 27.6 (CMe3); 31.4 (3 Me)
13.7 (Me);
22.1, 31.4,
31.6 (3 CH2)
18.4, 20.1 (4 Me) 266 [M]+
5i
5j
78.0, 90.9 29.5 (2 CMe2); 34.3 (CSMe) 28.1 (3 CH); 29.8 (CC≡C); 14.9 (Me)
18.0, 20.3 (4 Me) 302 [M]+
18.2, 20.5 (4 Me) 244 [M]+
36.2 (3 CH2); 43.5 (3 CH2)
81.8, 90.1 31.4 (2 CMe2); 34.7 (CSMe) 124.1 (C(1)); 127.5,
128.2, 131.7 (Ph)
15.2 (Me)
constant of 5.3 Hz assigned to the methylene group in the
cyclopropane ring, and a characteristic set of signals for
the protons of the vinyl group at δ 5.1—6.2. The 13C NMR
spectrum of compound 8a has signals for the carbon atꢀ
oms of the triple bond at δ 79 and 90, signals of the vinyl
fragment at δ 114.8 and 140.3, and signals of the tertꢀbutyl,
methyl, and phenyl groups.
We established the structure of compound 9 based priꢀ
marily on the following characteristic signals in the
1H NMR spectrum: a broadened singlet at δ 6.8 and a
doublet with the spinꢀspin coupling constant of 1 Hz at
δ 5.94, which correspond to the protons at the double
bonds at positions 2 and 4 of the cycloheptatriene ring,
respectively, and a triplet at δ 5.27 assigned to the proton at
position 6, which is slightly broadened due to longꢀrange
spinꢀspin couplings. As expected, the signal of the methyl
group in triene 9 is observed at substantially lower field
(δ 1.9) compared to the analogous signal for cyclopropane
8a (δ 1.59), and the signal of the methylene group is shifted
to δ ~2.4 due to the influence of the double bonds.
According to the results of quantumꢀchemical calcuꢀ
lations,13 (alkꢀ1ꢀynyl)alkylthiocarbenes prepared in the
present study are in singlet states. Therefore, we characꢀ
terized these species using the Moss method.15

2552
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004
Shavrin et al.
Scheme 3
Experimental
The GLC analysis of the starting compounds and reaction
products was carried out on a Hewlett—Packard 5890 Series II
instrument equipped with a 30 m×0.153ꢀmm capillary column
and a Hewlett—Packard 3396A automatic integrator. The 1H and
13C NMR spectra were recorded on a Bruker ACꢀ200p specꢀ
trometer in CDCl3 with Me4Si as the internal standard. The
mass spectra were recorded on a Finnigan MAT INCOSꢀ50
GLCꢀmass spectrometer.
The starting acetylenic sulfides 3 were prepared from the
corresponding propargyl chlorides according to a known proceꢀ
dure.17
Synthesis of 1ꢀsubstituted 1ꢀchloroꢀ3ꢀorganylthiopropaꢀ
1,2ꢀdienes 1a—g (general procedure). NꢀChlorosuccinimide
(10.5 mmol) was added to a solution of sulfide 3 (10 mmol) in
CCl4 (10—15 mL). The reaction mixture was stirred at room
temperature for 2—4 h, the course of the reaction being moniꢀ
tored by GLC. After completion of the reaction, the mixture
was filtered, the solvent was removed in vacuo, and a paleꢀ
yellow liquid was obtained.
According to the 1H NMR spectroscopic data (see Table 1),
the reactions with sulfides 3c—g afforded products, 75—85% of
which are accounted for by the corresponding allenes 1a—g.
Under analogous conditions, the reaction of compound 3a gave
a mixture of allene 1a and acetylene 4a in a ratio of 1 : 1,
whereas the reaction of 3b produced a mixture of 1b and 4b in a
ratio of 1 : 3.
Reagent and conditions: i. ButOK, hexane, –20 °C.
For this purpose, we determined the relative reactiviꢀ
ties (ki/k0) of carbene 2d, which was generated from haꢀ
lide 1d under the action of ButOK, with respect to a series
of methylꢀsubstituted olefins, by the competitive reaction
method with the use of 2ꢀmethylpropene as the reference
compound (ki/k0 = 1). The results of the present study
and the analogous data for dichlorocarbene16 are given in
Table 5. The selectivity index calculated as the slope of
the curve in the coordinates X = log(ki/k0) + 1 for CCl2
and Y = log(ki/k0) + 1 for carbene 2d is 0.59, which is
indicative15 of the electrophilic character of this carbene.
The nature of the substituents at the triple bond and the
sulfur atom would not have a considerable effect on the
properties of carbenes 2. Hence, other (alkꢀ1ꢀynyl)orgaꢀ
nylthiocarbenes, most likely, will also exhibit electrophilic
properties.
1ꢀChloroꢀ4,4ꢀdimethylꢀ1ꢀphenylthiopentꢀ2ꢀyne
(4a).
1H NMR, δ: 1.21 (s, 9 H, But); 5.86 (s, 1 H, CHCl); 7.20—7.70
(m, 5 H, Ph). 13C NMR, δ: 27.6 (CMe3); 30.4 (3 CH3);
55.7 (CHCl); 74.3, 99.6 (C≡C); 128.4, 129.4, 129.6 (Ph);
131.2 (C(1), Ph).
1
1ꢀChloroꢀ1ꢀmethylthioꢀ3ꢀphenylpropꢀ2ꢀyne (4b). H NMR,
δ: 2.50 (s, 3 H, SMe); 5.96 (s, 1 H, CHCl); 7.30—7.45 (m, 3 H,
mꢀH, pꢀH, Ph); 7.62 (br.d, 2 H, oꢀH, Ph, J = 8.2 Hz). 13C NMR,
δ: 13.7 (SMe); 54.5 (CHCl); 83.9, 88.8 (C≡C); 121.5 (C(1),
Ph); 128.3, 129.1, 131.7 (Ph).
Synthesis of 1ꢀ(alkꢀ1ꢀynyl)ꢀ1ꢀorganylthiocyclopropanes 5a—j
from 1ꢀsubstituted 1ꢀchloroꢀ3ꢀorganylthiopropaꢀ1,2ꢀdienes 1a—f
(general procedure). A solution of the starting halide (2 mmol)
in hexane (1 mL) was added to a mixture of ButOK (670 mg,
6 mmol), the starting alkene (6 mmol), and hexane (10 mL)
at –20 °C. The reaction mixture was stirred for 30 min and
allowed to warm to room temperature. Then the reaction mixꢀ
ture was treated with water, the organic layer was separated, and
the aqueous layer was extracted with diethyl ether (3×10 mL).
The combined organic layers were dried with magnesium sulꢀ
fate, the solvent was evaporated, and the cyclopropane product
was isolated from the residue by vacuum distillation (see Table 2).
The yields, boiling points, and the ratios between the cis and
trans isomers of cyclopropanes 5 are given in Table 2. The
spectroscopic characteristics of cyclopropanes 5 are listed in
Tables 3 and 4.
To summarize, we prepared previously unknown alkꢀ
1ꢀynyl(organylthio)carbenes 2 using an original proceꢀ
dure and demonstrated that these species can add at the
double bond of olefins with different structures to form
the corresponding cyclopropane adducts.
Table 5. Relative reactivities of 3,3ꢀdimethylbutꢀ1ꢀ
ynyl(pꢀtolylthio)carbene 2d and dichlorocarbene
Alkene
ki/k0
Reaction of (3,3ꢀdimethylbutꢀ1ꢀynyl)phenylthiocarbene (2a)
with 2ꢀbutꢀ1,3ꢀdiene. A solution of chloroallene 1a (475 mg,
2 mmol) in hexane (1 mL) was added to a mixture of ButOK
(670 mg, 6 mmol), 2ꢀmethylbutꢀ1,3ꢀdiene (410 mg, 6 mmol),
and hexane (10 mL) at –20 °C. The reaction mixture was stirred
for 30 min, allowed to warm to room temperature, and treated
2d
Cl2C16
2ꢀMethylpropene
2ꢀMethylbutꢀ2ꢀene
2,3ꢀDimethylbutꢀ2ꢀene
1.0
2.05
3.20
1.0
3.05
7.41

(Alkꢀ1ꢀynyl)organylthiocarbenes
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 11, November, 2004 2553
with water. The organic layer was separated and the aqueous
layer was extracted with diethyl ether (3×10 mL). The combined
organic layers were dried with magnesium sulfate, the solvent
was evaporated, and a mixture of cyclopropane 8a and cycloꢀ
heptatriene 9 was isolated from the residue by vacuum microꢀ
distillation (1 Torr, the temperature of the bath was 140—150 °C)
in a ratio of 1 : 0.8 (NMR spectroscopic data) in a total yield
of 255 mg.
the Russian Federation (Program for Support of Young
Scientists and Leading Scientific Schools of the Rusꢀ
sian Federation, Grants MKꢀ2383.2003.03 and
NShꢀ1987.2003.03).
References
1ꢀ(3,3ꢀDimethylbutꢀ1ꢀynyl)ꢀ2ꢀmethylꢀ1ꢀphenylthioꢀ2ꢀvinylꢀ
1
cyclopropane (8a). H NMR, δ: 1.19 (s, 9 H, But); 1.40 (d, 1 H,
1. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov,
Mendeleev Commun., 2003, 52.
CH2, J = 5.3 Hz); 1.44 (d, 1 H, CH2, J = 5.3 Hz); 1.59 (s, 3 H,
Me); 5.18 (dd, 1 H, =CH2, J = 10.7 Hz, J = 1.3 Hz); 5.25 (dd,
1 H, =CH2, J1 = 17.3 Hz, J2 = 1.3 Hz); 6.10 (dd, 1 H, —CH=,
J1 = 10.7 Hz, J2 = 17.3 Hz); 7.20—7.50 (m, 5 H, Ph). 13C NMR,
δ: 19.7 (Me); 27.9 (CMe3); 30.7 (CH2, cycloꢀC3H2); 31.2 (3 Me);
32.2, 35.9 (2 C, cycloꢀC3H2); 79.1, 90.1 (C≡C); 114.8 (=CH2);
125.6, 128.3, 128.7 (Ph); 136.4 (C(1), Ph); 140.3 (—CH=).
1ꢀtertꢀButylꢀ5ꢀmethylꢀ3ꢀphenylthiocycloheptaꢀ1,3,5ꢀtriene
(9). 1H NMR, δ: 1.12 (s, 9 H, But); 1.91 (br.s, 3 H, Me); 2.43 (d,
2 H, CH2, J = 6.7 Hz); 5.25 (br.t, 1 H, C(5)H, cycloꢀC7H5, J =
6.7 Hz); 5.94 (d, 1 H, C(2)H or C(4)H, cycloꢀC7H5, J = 1 Hz);
6.80 (d, 1 H, C(2)H or C(4)H, cycloꢀC7H5, J = 1 Hz); 7.20—7.50
(m, 5 H, Ph). 13C NMR, δ: 20.8 (Me); 29.4 (3 Me); 35.9 (CMe3);
120.2 (C(6)); 120.6, 133.6 (C(2), C(4)); 122.0, 123.2 (C(1),
C(4)); 125.9, 128.7, 129.7 (Ph); 136.1, 136.5 (C(3), Cipso, Ph).
Determination of the relative reactivities of (3,3ꢀdimethylꢀ
butꢀ1ꢀynyl)ꢀparaꢀtolylthiocarbene (2d) generated from chloroꢀ
allene 1d in the reaction with ButOK. Potassium tertꢀbutoxide
(110 mg, 1 mmol) was added to a solution of weighed samples
(10—15 mmol) of 2,3ꢀdimethylbutꢀ2ꢀene and 2ꢀmethylbutꢀ2ꢀ
ene in hexane (25 mL). The reaction mixture was cooled
to a temperature from –10 to –20 °C, and 2ꢀmethylpropene
(350—650 mg, 7—12 mmol) was condensed into this mixture.
The flask was sealed with a rubber stopper and warmed to room
temperature. Then a solution of chloride 1d (1 mmol) in hexane
(1—2 mL) was added. After 30 min, the reaction mixture was
quenched with water and the organic layer was analyzed by GLC.
Three experiments were carried out and the results of these
experiments were averaged. The weight ratios of cyclopropanes
were determined using a detector, which was preliminarily caliꢀ
brated against pure samples. The ratios ki/k0 for carbene 2d with
respect to the corresponding alkene were calculated from these
data according to the equation ki/k0 = (ni/n0)•(m0/mi), where
ni/n0 is the ratio of the amounts of adducts of carbene 2c with
iꢀth alkene and 2ꢀmethylpropene and m0/mi is the molar ratio of
2ꢀmethylpropene to iꢀth alkene.
2. U. Mislitz and A. de Meijere, Methoden der organischen
Chemie, HoubenꢀWeyl, Stuttgart, Georg Thieme, 1989, E19b,
Teil 1, 769.
3. A. de Meijere and R. R. Kostikov, Synthesis, 1991, 547.
4. K. N. Shavrin, I. B. Shvedova, and O. M. Nefedov, Izv.
Akad. Nauk SSSR, Ser. Khim., 1991, 2559 [Bull. Acad. Sci.
USSR, Div. Chem. Sci., 1991, 40, 2235 (Engl. Transl.)].
5. K. N. Shavrin, I. V. Krylova, I. B. Shvedova, G. P.
Okonnishnikova, I. E. Dolgy, and O. M. Nefedov, J. Chem.
Soc., Perkin Trans. 2, 1992, 1875.
6. K. N. Shavrin, I. V. Krylova, I. E. Dolgii, and O. M. Nefedov,
Izv. Akad. Nauk, Ser. Khim., 1992, 41 [Bull. Russ. Acad. Sci.,
Div. Chem. Sci., 1992, 1128 (Engl. Transl.)].
7. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov, Izv.
Akad. Nauk, Ser. Khim., 2002, 1143 [Russ. Chem. Bull., Int.
Ed., 2002, 51, 1143].
8. Yu. V. Tomilov, G. P. Okonnishnikova, E. V. Shulishov,
K. N. Shavrin, and O. M. Nefedov, Izv. Akad. Nauk, Ser.
Khim., 1998, 2278 [Russ. Chem. Bull., 1998, 47, 2208 (Engl.
Transl.)].
9. M. FranckꢀNeumann, P. Geoffroy, M. Miesch, and D. F.
Zaragoza, Tetrahedron Lett., 1990, 4121.
10. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov,
Mendeleev Commun., 2002, 224.
11. M. FranckꢀNeumann and P. Geoffroy, Tetrahedron Lett.,
1983, 1779.
12. A. Roedig, Methoden der organischen Chemie, HoubenꢀWeyl,
Stuttgart, Georg Thieme, 1960, V/4, 773.
13. V. I. Faustov, K. N. Shavrin, and O. M. Nefedov, Izv. Akad.
Nauk, Ser. Khim., 2005, No. 3 [Russ. Chem. Bull., Int. Ed.,
2005, 54, No. 3].
14. R. A. Moss and R. C. Munjal, Synthesis, 1979, No. 6, 425.
15. R. A. Moss, Acc. Chem. Res, 1980, 13, 58.
16. R. A. Moss and R. Gerstl, J. Org. Chem., 1963, 32, 2268.
17. A. Schöberl and A. Wagner, Methoden der organischen
Chemie, HoubenꢀWeyl, Stuttgart, Georg Thieme,
1955, 9, 107.
The ratios ki/k0 are given in Table 5.
This study was financially supported by the Russian
Foundation for Basic Research (Project No. 96ꢀ03ꢀ
32907a) and the Council on Grants of the President of
Received October 19, 2004