A novel stereoselective synthesis of trisubstituted 1,3-dienes by a hydrostannylation-Stille tandem reaction of alkylarylacetylenes with alkenyl halides

Article abstract of DOI:10.3184/030823410X12680741110954

Trisubstituted 1,3-dienes can be stereoselectively synthesised in one pot under mild conditions, in good yields, by the hydrostannylation of alkylarylacetylenes, followed by the Stille cross-coupling with alkenyl halides.

Full text of DOI:10.3184/030823410X12680741110954

JOURNAL OF CHEMICAL RESEARCH 2010
RESEARCH PAPER 175
MARCH, 175–177
A novel stereoselective synthesis of trisubstituted 1,3-dienes by a
hydrostannylation-Stille tandem reaction of alkylarylacetylenes with
alkenyl halides
Hean Zhanga,Yan Yub, Wenyan Haob and Mingzhong Caib*
aDepartment of Chemistry, College of Science, Nanchang University, Nanchang 330047, P. R. China
bDepartment of Chemistry, Jiangxi Normal University, Nanchang 330022, P. R. China
Trisubstituted 1,3-dienes can be stereoselectively synthesised in one pot under mild conditions, in good yields,
by the hydrostannylation of alkylarylacetylenes, followed by the Stille cross-coupling with alkenyl halides.
Keywords: hydrostannylation, 1,3-diene, alkylarylacetylene, Stille coupling, tandem reaction
The stereocontrolled synthesis of conjugated dienes has
attracted considerable interest in organic chemistry because of
their appearance in a wide variety of biologically active mole-
cules and their key synthetic intermediates.1–3 The synthesis of
1,3-dienes for use in the Diels-Alder reaction is still an impor-
tant challenge in organic synthesis4,5 although other elegant
uses of these compounds have been developed.6 Conjugated
dienes are usually prepared by utilising either a Wittig type
approach7,8 or through transition-metal-catalysed coupling
reactions of stereodefined vinyl halides with vinyl organome-
tallic compounds.9,10 Kasatkin and Whitby reported the inser-
tion of 1-lithio-1-halo-buta-1,3-diene into organozirconocenes
providing a stereocontrolled synthesis of (1E,3Z)-1,3-dienes.11
Recently, Molander and Yokoyama reported one-pot stereose-
lective synthesis of trisubstituted 1,3-dienes via sequential
Suzuki-Miyaura cross-coupling with alkenyl- and alkyltri-
fluoroborates.12 Tanaka et al. reported rhodium-catalysed
regio- and stereoselective codimerisation of alkenes and
electron-deficient internal alkynes leading to trisubstituted
1,3-dienes.13
The tandem reaction has recently been of interest for organic
synthesis because it offers a convenient and economical
method with which to prepare target organic molecules.14–17
The palladium-catalysed hydrostannylation of alkynes and the
Stille coupling reaction are acknowledged as useful tools for
constructing complex organic molecules. However, to the best
of our knowledge, there have been no reports on palladium-
catalysed tandem hydrostannylation-Stille coupling reaction
of tributyltin hydride with alkylarylacetylenes and alkenyl
halides to date. Herein we wish to report that trisubstituted 1,3-
dienes can be stereoselectively synthesised in one pot under
mild conditions, in good yields, by the hydrostannylation of
alkylarylacetylenes, followed by the Stille cross-coupling with
alkenyl halides.
reported22 stereospecific cross-coupling of vinyl halides with
vinyl tin reagents catalysed by palladium. Considering the
fact that both the hydrostannylation and Stille reactions were
catalysed by palladium complexes, we tried to combine
the two reactions, in one pot, to synthesise stereoselectively
trisubstituted 1,3-dienes (Scheme 1).
We found that, after the hydrostannylation reaction of
alkylarylacetylenes 1 with Bu3SnH using 3 mol% PdCl2(PPh3)2
in THF at 25 °C for 30 min, solvent removal under reduced
pressure and stirring of the residue with DMF, alkenyl iodides
3 and 75 mol% CuI at room temperature for 24 h, the trisubsti-
tuted 1,3-dienes 4 were obtained in good yields. The experi-
mental results are summarised in Table 1. As shown in Table 1,
the hydrostannylation-Stille tandem reaction of Bu3SnH with a
variety of alkylarylacetylenes and alkenyl iodides proceeded
smoothly under very mild conditions to afford stereoselec-
tively the corresponding trisubstituted 1,3-dienes 4. The Stille-
coupling reaction of the intermediates 2 with alkenyl bromides
also proceeded smoothly under the same reaction conditions,
giving the corresponding coupled products in good yields after
24 h of reaction time. However, the Stille coupling reaction of
the intermediates 2 with alkenyl chlorides did not occur at all.
Investigation of the crude products 4 by 1H NMR spectros-
copy (400 MHz) showed their isomeric purities of more than
98%. One olefinic proton signal of compounds 4a–j, except
4h, splits characteristically into one triplet at δ = 5.51–5.93
with coupling constant J = 6.4–7.6 Hz, which indicated that
the hydrostannylation to the alkylarylacetylenes had taken
place with strong preference for the addition of the tin atom at
the carbon adjacent to the aryl group. It is well documented
that the Stille cross-coupling reaction of vinylstannanes with
organic halides in the presence of a palladium catalyst occurs
with retention of configuration.20,21 The (E)-configuration of
the compounds 4a–j at the double bond originating from the
1
Palladium-catalysed hydrostannylation of alkynes provides
a simple, general route for the synthesis of vinylstannanes.18
Alami et al.19 reported that the palladium-catalysed hydrostan-
nylation of alkylarylacetylenes with Bu3SnH in THF at room
temperature was highly regio- and stereoselective, giving
(E)-α-arylvinylstannanes in high yields. It is well known that
vinylstannanes can undergo the palladium-catalysed cross-
coupling reaction with organic halides.20,21 Stille and Groh
alkenyl halide has been confirmed by their H NMR spectra
which show a doublet at δ = 6.20–7.01 with a coupling
constant of 15.6–16.0 Hz, giving evidence of the retention of
the E-configuration of the starting alkenyl halides. In addition,
the (Z)-configuration at the double bond originating from the
vinylstannane [C(4) = C(5)] of compound 4c was confirmed
by the NOESY in the 1H NMR spectrum. An enhancement of
the allylic protons was observed as the vinylic proton (δ = 5.72)
Scheme 1
* Correspondent. E-mail: caimzhong@163.com

176 JOURNAL OF CHEMICAL RESEARCH 2010
Table 1 Synthesis of trisubstituted 1,3-dienes (4a–j)
1H), 5.86 (t, J = 7.6 Hz, 1H), 1.98–1.94 (m, 2H), 1.36–1.20 (m, 8H),
0.85 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ 141.2, 138.2,
137.7, 135.1, 133.4, 129.6, 129.0, 128.5 128.2, 127.0, 126.8, 126.2,
31.7, 29.7, 29.3, 28.9, 22.6, 14.1; MS (EI, 70 eV): m/z 290 (M+, 12),
219 (29), 205 (39), 105 (90), 57 (100). Anal. Calcd for C22H26:
C, 90.98; H, 9.02. Found: C, 90.71; H, 9.25%.
Entry
R
Ar
R1
X
Product Yielda/%
1
2
3
4
5
6
7
8
9
n-C H13 Ph
n-C6H13 Ph
Ph
I
I
I
I
I
I
I
I
I
4a
4b
4c
4d
4e
4f
4g
4h
4i
78
75
69
80
70
77
74
64
67
n-C4H9
MeOCH2
n-C6H13
MeOCH2
Ph
n-C6H
Ph
n-C6H13 4-MeC6H4
(5E,7Z)-7-Phenyltetradeca-5,7-diene (4b): Oil. IR (neat): ν (cm−1)
3058, 2932, 2860, 1724, 1600, 1493, 1465, 1379, 963, 703; 1H NMR
(400 MHz, CDCl3): δ 7.37–7.27 (m, 3H), 7.10 (d, J = 7.2 Hz, 2H),
6.23 (d, J = 15.6 Hz, 1H), 5.58 (t, J = 7.6 Hz, 1H), 5.10 (dt, J = 15.6,
7.6 Hz, 1H), 2.05–2.00 (m, 2H), 1.90–1.85 (m, 2H), 1.34–1.16 (m,
12H), 0.89–0.84 (m, 6H); 13C NMR (100 MHz, CDCl ): δ 141.1,
139.0, 134.2, 131.6, 131.3, 129.6, 127.9, 126.5, 32.5, 31.73, 31.6, 29.8,
28.9, 28. 9, 22.6, 22.3, 14.06, 13.9; MS (EI, 70 eV): m/z 270 (M+, 1.1),
159 (24), 105 (100), 77 (41). Anal. Calcd for C20H30: C, 88.82;
H, 11.18. Found: C, 88.59; H, 11.37%.
n-C6H13 Ph
n-C4H9
n-C4H99
Me4
MeO-
CH2CH2
Ph
Ph
n-C4H9
Ph
Ph
Ph
4-ClC6H4
10
11
12
13
MeOCH2 2-MeOC6H4 n-C4H9
I
4j
62
79
72
68
n-C H
n-C64H193 Ph
Ph
Ph
Br 4a
n-C6H13 Ph
MeOCH2 Br 4c
n-C4H9 Br 4g
(2E,4Z)-1-Methoxy-4-phenylundeca-2,4-diene (4c): Oil. IR (neat):
ν (cm−1) 3058, 2927, 2854, 1729, 1595, 1493, 1449, 1122, 960, 703;
1H NMR (400 MHz, CDCl3): δ 7.35 (t, J = 7.4 Hz, 2H), 7.27 (m, 1H),
7.12 (d, J = 6.8 Hz, 2H), 6.45 (d, J = 15.6 Hz, 1H), 5.72 (t, J = 7.6 Hz,
1H), 5.21 (dt, J = 15.6, 6.4 Hz, 1H), 3.91 (d, J = 6.4 Hz, 2H), 3.30 (s,
3H), 1.94–1.88 (m, 2H), 1.34–1.16 (m, 8H), 0.84 (t, J = 7.2 Hz, 3H);
13C NMR (100 MHz, CDCl ): δ 140.3, 138.2, 137.1, 134.4, 129.5,
128.1, 126.8, 126.1, 73.1, 58.30, 31.7, 29.6, 29.1, 28.9, 22.6, 14.10; MS
(EI, 70 eV): m/z 258 (M+, 1.5), 120 (35), 105 (100), 77 (57). Anal.
Calcd for C18H26O: C, 83.67; H, 10.14. Found: C, 83.43; H, 9.97%.
(7Z,9E)-8-Tolylhexadeca-7,9-diene (4d): Oil. IR (neat): ν (cm−1)
3057, 2926, 2858, 1712, 1600, 1493, 1456, 1378, 961, 702; 1H NMR
(400 MHz, CDCl ): δ 7.16 (d, J = 8.0 Hz, 2H), 6.97 (d, J = 8.0 Hz,
2H), 6.20 (d, J =315.6 Hz, 1H), 5.51 (t, J = 7.6 Hz, 1H), 5.06 (dt,
J = 15.6, 7.6 Hz, 1H), 2.35 (s, 3H), 2.02–1.97 (m, 2H), 1.90–1.84 (m,
2H), 1.35–1.15 (m, 16H), 0.90–0.85 (m, 6H); 13C NMR (100 MHz,
CDCl3): δ 141.3, 139.4, 134.4, 132.2, 131.8, 130.2, 126.8, 125.2, 32.9,
31.7, 31.7, 29.9, 29.8, 29.4, 28.9, 28.9, 22.6, 21.6, 14.1, 14.0; MS (EI,
70 eV): m/z 312 (M+, 1.8), 91 (45), 57 (100). Anal. Calcd for C23H36:
C, 88.39; H, 11.61. Found: C, 88.13; H, 11.84%.
a Isolated yield based on alkylarylacetylene 1 used.
of 4c was irradiated. There was no correlation between the
vinylic proton (δ = 5.72) and aromatic protons. Correlation
between the allylic protons and aromatic protons was observed.
Correlation between the vinylic proton (δ = 5.72) and
another vinylic proton (δ = 6.45) was also observed. The NOE
results indicate that the compound 4c has the expected (Z)-
configuration at C(4) = C(5) and the Pd-catalysed cross-
coupling reaction of (E)-α-arylvinylstannanes 2 with alkenyl
halides occurs with configuration retention of both the starting
intermediates 2 and the alkenyl halides.
In summary, we have developed an efficient and stereose-
lective one-pot method for the synthesis of trisubstituted
1,3-dienes via the hydrostannylation-Stille coupling tandem
reaction of alkylarylacetylenes with alkenyl halides. The pres-
ent method has the advantages of readily available starting
materials, straightforward and simple procedures, mild reac-
tion conditions and good yields. The procedure should find
wide application to the synthesis of a large array of naturally
occurring substances having the trisubstituted 1,3-diene
system.
(2E,4Z)-1-Methoxy-4-phenyl-2,4-nonadiene (4e): Oil. IR (neat):
1
ν (cm−1) 2957, 2926, 1597, 1464, 1379, 1122, 968, 703; H NMR
(400 MHz, CDCl3): δ 7.34–7.26 (m, 3H), 7.12–7.10 (m, 2H), 6.45
(d, J = 15.6 Hz, 1H), 5.72 (t, J = 7.2 Hz, 1H), 5.20 (dt, J = 15.6, 6.0
Hz, 1H), 3.91 (d, J = 6.0 Hz, 2H), 3.30 (s, 3H), 1.95–1.89 (m, 2H),
1.33–1.19 (m, 4H), 0.85 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz,
CDCl3): δ 140.3, 138.2, 137.1, 134.4, 129.5, 128.1, 126.8, 126.1, 73.1,
57.9, 31.9, 28.8, 22.3, 14.0; MS (EI, 70 eV): m/z 230 (M+, 6), 105
(100), 77 (54), 57 (65). Anal. Calcd for C16H22O: C, 83.43; H, 9.63.
Found: C, 83.20; H, 9.82%.
Experimental
1H NMR spectra were recorded on a Bruker AC-P400 (400 MHz)
spectrometer with TMS as an internal standard using CDCl3 as the
solvent. 13C NMR (100 MHz) spectra were recorded on a Bruker
AC-P400 (400 MHz) spectrometer using CDCl as the solvent. IR
spectra were determined on an FTS-185 instru3ment as neat films.
Mass spectra were obtained on a Finnigan 8239 mass spectrometer.
Microanalyses were measured using a Yanaco MT-3 CHN microele-
mental analyser. All reactions were carried out in pre-dried glassware
(150 °C, 4 h) and cooled under a stream of dry Ar. THF was freshly
distilled from sodium-benzophenone prior to use. DMF was dried by
distillation over calcium hydride. Alkylarylacetylenes were prepared
according to the literature procedure.23
(1E,3Z)-1,3-Diphenylocta-1,3-diene (4f): Oil. IR (neat): ν (cm−1)
3060, 3029, 2956, 2871, 1705, 1599, 1494, 1455, 1379, 965, 754, 700;
1H NMR (400 MHz, CDCl ): δ 7.43–7.39 (m, 2H), 7.35–7.24 (m, 5H),
7.21–7.14 (m, 3H), 6.99 (3d, J = 16.0 Hz, 1H), 5.98 (d, J = 16.0 Hz,
1H), 5.86 (t, J = 7.6 Hz, 1H), 2.00–1.94 (m, 2H), 1.39–1.31 (m, 2H),
1.29–1.22 (m, 2H), 0.83 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz,
CDCl3): δ 141.2, 138.2, 137.7, 135.1, 133.4, 129.6, 129.1, 128.5,
128.1, 127.0, 126.8, 126.2, 31.9, 29.0, 22.3, 13.9; MS (EI, 70 eV):
m/z 262 (M+, 8.5), 105 (100), 77 (56), 57 (87). Anal. Calcd for C20H22:
C, 91.55; H, 8.45. Found: C, 91.28; H, 8.67%.
(5Z,7E)-6-Phenyldodeca-5,7-diene (4g): Oil. IR (neat): ν (cm−1)
3058, 3023, 2958, 2872, 1723, 1600, 1494, 1466, 1379, 983, 703; 1H
NMR (400 MHz, CDCl3): δ 7.37–7.27 (m, 3H), 7.10 (d, J = 7.6 Hz,
2H), 6.23 (d, J = 15.6 Hz, 1H), 5.58 (t, J = 7.6 Hz, 1H), 5.11 (dt,
J = 15.6, 7.6 Hz, 1H), 2.06–2.00 (m, 2H), 1.93–1.86 (m, 2H), 1.33–
1.20 (m, 8H), 0.87–0.79 (m, 6H); 13C NMR (100 MHz, CDCl3):
δ 141.1, 139.0, 134.2, 131.6, 131.3, 129.5, 127.9, 126.5, 32.5, 32.1,
31.6, 28.7, 22.3, 22.3, 13.9, 13.9; MS (EI, 70 eV): m/z 242 (M+, 1.3),
105 (100), 77 (47). Anal. Calcd for C18H26: C, 89.19; H, 10.81. Found:
C, 88.97; H, 10.97%.
General procedure for the synthesis of trisubstituted 1,3-dienes
(4a–j)
A 25 mL, two-necked, round-bottom flask equipped with a magnetic
stir bar and argon was charged sequentially with the alkylarylacety-
lene (1.0 mmol), THF (2 mL), PdCl2(PPh3)2 (0.03 mmol) and Bu SnH
(1.1 mmol). The mixture was stirred at 25 °C for 30 min. The3n the
solvent was removed under reduced pressure and the residue was dis-
solved in DMF (8 mL). The alkenyl halide (1.1 mmol) and CuI (0.75
mmol) were added and the mixture was stirred for 24 h at room tem-
perature and monitored by TLC (SiO ) for the disappearance of the
intermediate 2. The reaction mixture 2was diluted with diethyl ether
(30 mL), filtered and then treated with 20% aqueous KF (10 mL) for
30 min before being dried and concentrated. The residue was purified
by column chromatography on silica gel, eluting either with a mixture
of diethyl ether and petroleum ether or just petroleum ether.
(1E,3Z)-1,3-Diphenyldeca-1,3-diene (4a): Oil. IR (neat): ν (cm−1)
3059, 3027, 2927, 2854, 1708, 1598, 1494, 1456, 1377, 962, 750, 702;
1H NMR (400 MHz, CDCl ): δ 7.43–7.39 (m, 2H), 7.35–7.24 (m, 5H),
7.19–7.16 (m, 3H), 7.01 (3d, J = 16.0 Hz, 1H), 5.98 (d, J = 16.0 Hz,
(1E,3Z)-1,3-Diphenylpenta-1,3-diene (4h): Oil. IR (neat): ν (cm−1)
3058, 3026, 1625, 1598, 1494, 962, 702; 1H NMR (400 MHz, CDCl3):
δ 7.44–7.14 (m, 10H), 6.99 (d, J = 16.0 Hz, 1H), 6.01 (d, J = 16.0 Hz,
1H), 5.95 (q, J = 6.8 Hz, 1H), 1.63 (d, J = 6.8 Hz, 3H); 13C NMR
(100 MHz, CDCl3): δ 142.3, 142.2, 140.5, 138.0, 137.7, 129.7, 128.9,
128.5, 127.7, 127.0, 126.8, 126.2, 15.18; MS (EI, 70 eV): m/z 220
(M+, 4.7), 105 (100), 77 (67). Anal. Calcd for C17H16: C, 92.68; H,
7.32. Found: C, 92.41; H, 7.53%.
(1E,3Z)-1-Phenyl-3-(4-chlorophenyl)-6-methoxyhexa-1,3-diene
(4i): Oil. IR (neat): ν (cm−1) 3057, 3032, 2958, 1703, 1601, 1496,
1179, 1123, 962, 753, 702; 1H NMR (400 MHz, CDCl ): δ 7.43–7.15
(m, 9H), 7.01 (d, J = 16.0 Hz, 1H), 6.02 (d, J = 16.03Hz, 1H), 5.91

JOURNAL OF CHEMICAL RESEARCH 2010 177
References
(t, J = 7.6 Hz, 1H), 3.51 (t, J = 6.4 Hz, 2H), 3.29 (s, 3H), 2.97–2.91
(m, 2H); 13C NMR (100 MHz, CDCl3): δ 141.8, 139.1, 137.8, 135.7,
134.8, 129.8, 129.6, 128.8, 128.57, 127.3, 127.0, 126.3, 69.4, 58.1,
31.2; MS (EI, 70 eV): m/z 298 (M+, 35Cl, 2.1), 105 (100), 77 (51).
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1
1113, 967, 749; H NMR (400 MHz, CDCl3): δ 7.21–7.17 (m, 1H),
6.91–6.86 (m, 2H), 6.82 (d, J = 8.4 Hz, 1H), 6.25 (d, J = 15.6 Hz, 1H),
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55.1, 32.2, 31.2, 22.3, 14.0; MS (EI, 70 eV): m/z 260 (M+, 4.1), 57
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Received 8 February 2009; accepted 5 March 2010
Paper 100999 doi: 10.3184/030823410X12680741110954
Published online: 23 March 2010

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