Suzuki coupling reactions of (E)- and (Z)-chloroenynes with boronic acids: Versatile access to functionalized 1,3-enynes

Article abstract of DOI:10.1002/ejoc.200901137

A stereoselective, palladium-catalyzed, cross-coupling reaction between chloroenynes 4 and boronic acids was successfully developed. This procedure is general and provides de-sired functionalized enynes 1 in high yields. The scope and limitations of this new reaction are described.

Full text of DOI:10.1002/ejoc.200901137

FULL PAPER
DOI: 10.1002/ejoc.200901137
Suzuki Coupling Reactions of (E)- and (Z)-Chloroenynes with Boronic Acids:
Versatile Access to Functionalized 1,3-Enynes
Abdellatif Tikad,[a] Abdallah Hamze,[a] Olivier Provot,[a] Jean-Daniel Brion,[a] and
Mouâd Alami*[a]
Keywords: Cross-coupling / Enynes / Boron / Palladium / C–C coupling
A stereoselective, palladium-catalyzed, cross-coupling reac- sired functionalized enynes 1 in high yields. The scope and
tion between chloroenynes 4 and boronic acids was success-
limitations of this new reaction are described.
fully developed. This procedure is general and provides de-
bond are needed, this method is less suitable, because it
requires the preparation of stereodefined vinyl halides 3
through lengthy procedures. Therefore, this method is time
consuming and economically inefficient. From the stand-
point of flexibility, a method that employs a common start-
ing material as a precursor would have an obvious advan-
tage. In recent years, we showed that the use (E)- or (Z)-
chloroenynes 4 as synthetic intermediates presented several
advantages: (i) They are easily accessible in high stereoiso-
meric purity (Ն99.9%) by reaction of terminal alkynes 2
with commercially available (E)- or (Z)-1,2 dichloroethyl-
ene.[12] (ii) They are chemically stable and nonphotosensi-
tive. Additionally, we demonstrated that they are good part-
ners in metal-catalyzed coupling reactions with organome-
tallic reagents (Scheme 1, path b).[13]
Introduction
The 1,3-enyne moiety is an important unit found in many
compounds of biological interest,[1] including, hachijodine
G,[2] a cytotoxic sponge alkaloid, terbinafine,[3] an antifun-
gal agent used currently for the treatment of skin mycoses,
and neocarzinostatin,[4] an effective antitumor antibiotic.
Recently, a novel class of potent antitubulin agents contain-
ing this unit was reported by Lo[5] and our group.[6] 1,3-
Enynes have also found increasing application in organic
synthesis. Typically, they are valuable precursors for poly-
substituted benzenes,[7] conjugated dienes,[8] and polyenes.[9]
For these reasons, the design and synthesis of compounds
containing an enyne moiety have received considerable at-
tention in organic synthesis and have been extensively
studied. Among various methods developed to synthesize
Among the organometallic reagents used, we showed
1,3-enynes 1, the Pd–Cu-catalyzed Sonogashira coupling re- that Grignard compounds in the presence of a catalytic
[13a]
action between terminal alkynes 2 and vinyl halides 3 (I[10] amount of PdCl2(PPh3)2
reacted rapidly and cleanly
or Br,[10a] Cl[11]) is undoubtedly the most prevalent route to with 4 to efficiently introduce aryl and alkenyl substituents,
such unsaturated compounds (Scheme 1, path a). However, whereas to successfully transfer alkyl substituents contain-
when enynes 1 bearing various R substituents at the double ing β-hydrogen(s), the best routes involved the use of
Scheme 1. Synthetic strategies to target enynes 1.
iron[13b–13d] or manganese[13e] salts as catalysts. More re-
[a] Univ Paris-Sud, CNRS, BioCIS UMR 8076, Laboratoire de
Chimie, Thérapeutique, Faculté de Pharmacie,
cently, we reported a mild Pd-catalyzed procedure for the
synthesis of 1 by coupling 4 with organozincate species,
formed in situ by reaction of Grignard reagents with a cata-
5 rue J.-B. Clément, Châtenay-Malabry 92296, France
Fax: +33-1-46835828
E-mail: mouad.alami@u-psud.fr
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725

A. Tikad, A. Hamze, O. Provot, J.-D. Brion, M. Alami
FULL PAPER
lytic amount of ZnCl2.[13f] However, if this procedure is ap-
As a proper combination of base and solvent is very im-
propriate to transfer efficiently alkyl, alkenyl, or aryl groups portant for the success of the reaction, we then examined
onto the enyne moiety, it is limited to nonfunctionalized the influence of these parameters. After a series of assays
Grignard reagents. To enlarge the scope of the application (not shown in Table 1), we found that the combination in-
of chloroenynes chemistry to the synthesis of complex volving K2CO3/toluene at 100 °C led to 1a with a better
molecules, it was interesting to be able to couple function- conversion (76%; Table 1, Entry 4). When adding EtOH as
alized boronic acid reagents to introduce functionalities a cosolvent,[16] we were pleased to observe total conversion
from both substrate and reagent. Over the past few years, of 4a, and 1a was stereospecifically formed with an excel-
in particular, there has been an increased availability of lent yield (94%; Table 1, Entry 5). A similar result was ob-
boronic acids and esters.[14] Organoboron reagents exhibit tained when replacing the previous catalytic system by
greater functional group compatibility than organozinc or Pd(OAc)2/PPh3 (88%, 1.5 h; Table 1, Entry 6).
Grignard reagents. Moreover, the innocuous nature of
boronic acids, which are generally nontoxic and thermally
air- and moisture-stable, is a practical advantage of the Su-
zuki reaction relative to other coupling processes. To the
best of our knowledge, except the coupling reaction of
boronic acids with activated β-chloro-α,β-unsaturated esters
reported by Lemay,[15] the coupling of these mild organo-
metallic species with chloroenynes appears unprecedented.
Therefore, we turned our attention to investigate the reac-
tivity of various commercially available boronic acids
towards (E)- and (Z)-chloroenynes 4 in the presence of pal-
ladium catalysts. The results of this study are now reported.
Having optimized the reaction parameters, the scope of
the reaction was examined with a variety of functionalized
boronic acids and (E)- or (Z)-chloroenynes 4. The results
presented in Table 2 show that chloroenyne and boronic
acid substrates have been used successfully, and in all cases,
the coupling process is highly stereoselective. Performing
the reaction with 4b resulted in the formation of enyne 1b in
good yield and with total retention of the (Z) configuration
(76%; Table 2, Entry 2). Nonsubstituted chloroenyne 4c as
well as 4d bearing an electron-withdrawing group in the or-
tho position were also successfully transformed into their
corresponding enynes 1c and 1d, respectively, in good yields
(Table 2, Entries 3 and 4). The results reported in Entries 5
and 6 also indicate that both (E)- and (Z)-aliphatic chloro-
enynes 4e and 4f provided the required coupling enynes in
Results and Discussion
At first, we studied the coupling of (E)-chloroenyne 4a good yields and with excellent stereoselectivities. We then
with 4-methoxyphenylboronic acid as model substrates to es- turned our attention to the scope of the arylboronic acids.
tablish the best reaction conditions (Table 1). Initially, this Switching the methoxy substituent from the para to the or-
coupling was evaluated according to the protocol of Le- tho position to the boronic acid does not affect the overall
may[15] using Pd2(dba)3/SPHOS [SPHOS = 2-(dicyclohex- performance or the stereoselectivity of the reaction
ylphosphanyl)-2Ј,6Ј-dimethoxybiphenyl] as the catalyst sys- (Table 2, compare Entries 1 and 7). 1,3-Benzodioxyl and 2-
tem and K3PO4 as the base at room temperature. Under these naphthyl substituents were also successfully transferred
conditions, the coupling gave enyne 1a with retention of the onto chloroenyne 4a (Table 2, Entries 8 and 9). We were
E-double bond configuration, but with low conversion and pleased to observe that functionalized boronic acids substi-
overall yield (20%; Table 1, Entry 1). It is noteworthy that a tuted with an electron-withdrawing group (Cl, CH3CO,
significant amount of starting material was recovered un- CHO, NO2) were coupled in good yields and with reason-
changed, as judged by 1H NMR analysis. Increasing the tem- able reaction times (Table 2, Entries 10–13). The use of
perature to 70 °C improved the conversion of 4a to 53% after heteroaromatic- or alkenylboronic acid (Table 2, Entries 14
1 d (Table 1, Entry 2). Under the same conditions, replacing and 15) was also effective, giving rise to enyne 1n or 1o,
the catalyst system Pd2(dba)3/SPHOS by Pd(PPh3)4 resulted respectively, demonstrating the general character of the pre-
in a similar conversion (49%; Table 1, Entry 3).
sented method to transfer Csp2 substituents. In contrast,
Table 1. Pd-catalyzed Suzuki coupling between 4a and 4-methoxyphenylboronic acid.[a]
Entry Pd cat. (mol-%)/ligand (mol-%)
Solvent
Base (equiv.)
T [°C]
Time [h]
Conv. [%][b] Yield [%][c]
1
2
3
4
5
6
Pd2(dba)3 (5)/SPHOS (20)
Pd2(dba)3 (5)/SPHOS (20)
Pd(PPh3)4 (5)
Pd(PPh3)4 (5)
Pd(PPh3)4 (5)
Pd(OAc)2 (5)/PPh3 (10)
THF
THF
THF
K3PO4 (2)
K3PO4 (2)
K3PO4 (2)
K2CO3 (2)
K2CO3 (2)
K2CO3 (2)
25
70
70
100
100
100
3
24
24
24
1
24
53
49
76
100
100
20
–
–
–
94
88
toluene
toluene/EtOH (2:1)
toluene/EtOH (2:1)
1.5
1
[a] All reactions were performed with 1 equiv. of 4a and 1.2 equiv. of 4-MeOC6H4B(OH)2. [b] Conversion was determined by H NMR
analysis. [c] Yields were given for isolated products.
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Suzuki Coupling Reactions of (E)- and (Z)-Chloroenynes with Boronic Acids
Table 2. Reactivity of chloroenynes 4 with various functionalized boronic acids under palladium catalysis.[a]
[a] The reactions were performed with 1 equiv. of 4, 1.2 equiv. of RB(OH)2, 5 mol-% of Pd(PPh3)4, K2CO3 (2 equiv.), in toluene/EtOH
1
(2:1) at 100 °C. [b] Yields are given for isolated products. [c] Stereoisomeric purities were determined by H NMR analysis of the crude
product. [d] (3E,5E)/(3Z,5E) ratio.
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A. Tikad, A. Hamze, O. Provot, J.-D. Brion, M. Alami
FULL PAPER
ica gel 60F plates. Merck silica gel 60 (230-400 mesh) was used for
column chromatography. Chloroenynes 4c,[18] 4e,[19] 4f,[19] and 4g[15]
were prepared according to literature procedures.
under the same protocol, the coupling of n-butylboronic
acid with 4a failed and 1p resulting from carbon–chlorine
bond reduction was isolated as the major product (Table 2,
Entry 16). To improve this result, various combinations of
Pd/ligand/additive mixtures were examined. Thus, the use
of PdCl2(dppf) or Pd(OAc)2/dppf [dppf = 1,1Ј-bis(diphenyl-
phosphanyl)ferrocene] as catalytic systems also provided 1p
in 60–62% yield, whereas in the presence of CuI or Ag2O,
which may facilitate the transmetalation step, no reaction
occurred and 4a was recovered unchanged (data not
shown).
Finally, we extended the scope of our protocol to achieve
the coupling of a boronic acid with a chloroenyne having a
functionalized tetrasubstituted double bond. To this end, β-
chloro-α,β-unsaturated ester 4g was coupled with 4-meth-
oxyphenylboronic acid under the above conditions to suc-
cessfully give desired enyne product 1q in a good 77% yield
(Scheme 2).
Synthesis of (Z)-Chloroenynes 4b and 4d: To
a solution of
PdCl2(PPh3)2 (702 mg, 1 mmol), (Z)-1,2-dichloroethylene (3.88 g,
40 mmol), n-butylamine (2.92 g, 40 mmol), and 1-alkyne (20 mmol)
in ethyl ether (50 mL) was added CuI (380 mg, 2 mmol) at 0 °C
(exothermic reaction). The stirred reaction was kept at room tem-
perature for a night and treated with saturated NH4Cl solution
(25 mL). The aqueous layer was extracted with ethyl ether
(3ϫ20 mL), and the combined organic layer was washed success-
ively with aqueous HCl (0.2 , 15 mL), NaHCO3 (10 mL), and
H2O (2ϫ25 mL), dried with MgSO4, and concentrated under vac-
uum. Purification by flash chromatography afforded the expected
(Z)-chloroenynes.
(Z)-4-Chloro-1-(2-methoxyphenyl)but-3-en-1-yne (4b): Yellow oil
(3.11 g, 81%). 1H NMR (300 MHz, CDCl3): δ = 3.90 (s, 3 H, CH3),
6.14 (d, J = 7.4 Hz, 1 H, Hvinyl), 6.42 (d, J = 7.4 Hz, 1 H, Hvinyl),
6.89 (d, J = 8.2 Hz, 1 H, Harom), 6.93 (dd, J = 0.8, 7.5 Hz, 1 H,
Harom), 7.29–7.34 (m, 1 H, Harom), 7.47 (dd, J = 7.5, 1.7 Hz, 1 H,
Harom) ppm. 13C NMR (75 MHz, CDCl3): δ = 56.0 (CH3), 87.5
(Cq), 94.0 (Cq), 110.9 (CH), 112.1 (Cq), 112.6 (CH), 120.7 (CH),
128.0 (CH), 130.4 (CH), 133.9 (CH), 160.1 (C ) ppm. IR (neat): ν
˜
q
= 2201, 1578, 1489, 1433, 1264, 1119 cm–1. MS (APCI+): m/z =
193.0 [M + H]+. C11H9ClO (192.64): calcd. C 68.58, H 4.71; found
C 68.40, H 4.61.
Scheme 2. Synthesis of 1q. Reagents and conditions: (i) 4-methoxy-
phenylboronic acid (1.2 equiv.) Pd(PPh3)4 (5 mol-%), K2CO3
(2 equiv.), toluene/EtOH (2:1), 100 °C, 1 h.
(Z)-1-(2-Ethoxycarbonylphenyl)-4-chlorobut-3-en-1-yne (4d): Yellow
oil (2.85 g, 61%). 1H NMR (300 MHz, CDCl3): δ = 1.39 (t, J =
7.1 Hz, 3 H, CH3), 4.39 (q, J = 7.1 Hz, 2 H, CH2), 6.15 (d, J =
7.4 Hz, 1 H, Hvinyl), 6.46 (d, J = 7.4 Hz, 1 H, Hvinyl), 7.36–7.41 (m,
1 H, Harom), 7.44–7.49 (m, 1 H, Harom), 7.61 (d, J = 7.6 Hz, 1 H,
Harom), 7.95 (d, J = 7.8 Hz, 1 H, Harom) ppm. 13C NMR (75 MHz,
CDCl3): δ = 14.3 (CH3), 27.0 (CH2), 88.1 (Cq), 96.2 (Cq), 112.4
(CH), 123.1 (Cq), 128.5 (CH), 128.8 (CH), 130.4 (CH), 131.7 (CH),
Conclusions
In summary, we developed an efficient and general cata-
lytic system for the cross-coupling reaction of a wide range
of (Z)- or (E)-chloroenynes and arylboronic acids. The pro-
cess is stereoselective and provides good access to a series
of functionalized 1,3-enynes in good to excellent yields.
Moreover, the reaction tolerates several functional groups
on both coupling partners. Further developments will be
disclosed in due course.
132.2 (C ), 134.7 (CH), 166.2 (C ) ppm. IR (neat): ν = 1709, 1598,
˜
q
q
1482, 1366, 1249, 1130, 1080 cm–1. MS (APCI+): m/z = 235.0 [M
+ H]+. C13H11ClO2 (234.68): calcd. C 66.53, H 4.72; found C 66.35,
H 4.52.
(E)-4-Chloro-1-(2-methoxyphenyl)but-3-en-1-yne (4a): The same
procedure was used as that described for the (Z)-chloroenynes, ex-
cept that piperidine was used as a base instead of n-butylamine and
(E)-1,2-dichloroethylene instead of (Z)-1,2-dichloroethylene. Yel-
1
Experimental Section
low oil (3.04 g, 79%). H NMR (300 MHz, CDCl3): δ = 3.88 (s, 3
H, CH3), 6.20 (d, J = 13.6 Hz, 1 H, Hvinyl), 6.63 (d, J = 13.6 Hz,
1 H, Hvinyl), 6.88 (d, J = 8.1 Hz, 1 H, Harom), 6.92 (dd, J = 0.8,
7.5 Hz, 1 H, Harom), 7.27–7.33 (m, 1 H, Harom), 7.39 (dd, J = 1.6,
7.5 Hz, 1 H, Harom) ppm. 13C NMR (75 MHz, CDCl3): δ = 55.8
(CH3), 88.4 (2 Cq), 110.7 (CH), 111.8 (Cq), 114.2 (CH), 120.6 (CH),
General Comments: All glassware was oven-dried at 140 °C and all
reactions were conducted under a nitrogen atmosphere. Solvents
were dried by standard methods and distilled before use. Piperidine
and n-butylamine were dried and distilled from potassium hydrox-
ide prior to use. Pd(PPh3)4 was prepared following a literature pro-
cedure.[17] The compounds were all identified by usual physical
129.9 (CH), 130.3 (CH), 133.6 (CH), 159.9 (C ) ppm. IR (neat): ν
˜
q
= 1598, 1489, 1435, 1243, 1119, 1022 cm–1. MS (APCI+): m/z =
193.0 [M + H]+. C11H9ClO (192.64): calcd. C 68.58, H 4.71; found
C 68.45, H 4.60.
1
methods, that is, H NMR, 13C NMR, and IR spectroscopy, MS,
1
and elemental analysis. H and 13C NMR spectra were measured
in CDCl3 with a Bruker Avance 300. 1H chemical shifts are re-
ported in ppm from the peak of residual chloroform (δ =
7.27 ppm). The following abbreviations are used: m (multiplet), s
(singlet), d (doublet), t (triplet) dd (doublet of doublets). 13C chemi-
cal shifts are reported in ppm from the central peak of deuterio-
General Procedure for Suzuki Cross-Coupling: To a mixture of chlo-
roenyne (1 mmol) in toluene (4 mL) and EtOH (2 mL) was success-
ively added the desired boronic acid (1.2 mmol), K2CO3 (2 mmol),
and Pd(PPh3)4 (0.05 mmol). The reaction mixture was heated at
chloroform (δ = 77.14 ppm). IR spectra were measured with a Bruker 100 °C, under vigorous stirring and monitored by TLC until com-
Vector 22 spectrophotometer as neat samples. Elemental analyses
were performed with a Perkin–Elmer 240 analyzer. Mass spectra
were obtained by using a Bruker Esquire electrospray ionization
apparatus. Analytical TLC was performed on Merck precoated sil-
plete disappearance of starting material. The solvent was evapo-
rated in vacuo and water (10 mL) was added. After extraction with
CH2Cl2 (3ϫ10 mL), the combined organic layer was dried with
MgSO4, and the solvent was removed under reduced pressure. The
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Suzuki Coupling Reactions of (E)- and (Z)-Chloroenynes with Boronic Acids
crude material was purified by column chromatography to afford
the expected 1,3-enyne 1.
(Z)-1-(4-Methoxyphenyl)non-1-en-3-yne (1f): Yellow oil (189 mg,
83%). H NMR (300 MHz, CDCl3): δ = 0.93 (t, J = 7.1 Hz, 3 H,
1
CH3), 1.30–1.50 (m, 4 H, 2 CH2), 1.56–1.67 (m, 2 H, CH2), 2.41–
2.47 (m, 2 H, CH2), 3.83 (s, 3 H, CH3), 5.58 (dt, J = 2.5, 11.9 Hz,
1 H, Hvinyl), 6.49 (d, J = 11.9 Hz, 1 H, Hvinyl), 6.87 (d, J = 8.8 Hz,
2 H, Harom), 7.84 (d, J = 8.8 Hz, 2 H, Harom) ppm. 13C NMR
(75 MHz, CDCl3): δ = 14.2 (CH3), 20.0 (CH2), 22.4 (CH2), 28.5
(CH2), 31.3 (CH2), 55.4 (CH3), 79.5 (Cq), 97.3 (Cq), 105.9 (CH),
113.6 (2 CH), 129.9 (Cq), 130.0 (2 CH), 136.8 (CH), 159.5 (Cq)
(E)-1-(2-Methoxyphenyl)-4-(4-methoxyphenyl)but-3-en-1-yne (1a):
Yellow oil (248 mg, 94%). H NMR (300 MHz, CDCl3): δ = 3.72
1
(s, 3 H, CH3), 3.81 (s, 3 H, CH3), 6.22 (d, J = 16.2 Hz, 1 H, Hvinyl),
6.76–6.80 (m, 3 H, Harom), 6.84 (d, J = 7.5 Hz, 1 H, Harom), 6.92
(d, J = 16.2 Hz, 1 H, Hvinyl), 7.16–7.21 (m, 1 H, Harom), 7.27 (d, J
= 8.8 Hz, 2 H, Harom), 7.35 (dd, J = 1.6, 7.5 Hz, 1 H, Harom) ppm.
13C NMR (75 MHz, CDCl3): δ = 55.4 (CH3), 55.9 (CH3), 87.4 (Cq),
93.4 (Cq), 106.2 (CH), 110.7 (CH), 112.9 (Cq), 114.3 (2 CH), 120.6
(CH), 127.7 (2 CH), 129.5 (Cq), 129.6 (CH), 133.5 (CH), 140.7
ppm. IR (neat): ν = 2931, 1605, 1510, 1463, 1304, 1254, 1175,
˜
1033 cm–1. MS (APCI+): m/z = 229.0 [M + H]+. C16H20O (228.33):
calcd. C 84.16, H 8.83; found C 84.05, H 8.69.
(CH), 159.9 (C ), 160.1 (C ) ppm. IR (neat): ν = 2933, 1601, 1492,
˜
q
q
1434, 1245, 1174, 1019 cm–1. MS (APCI+): m/z = 265.0 [M + H]+.
(E)-1,4-Bis(2-methoxyphenyl)but-3-en-1-yne (1g): Yellow oil
(224 mg, 85%). 1H NMR (300 MHz, CDCl3): δ = 3.77 (s, 3 H,
CH3), 3.82 (s, 3 H, CH3), 6.45 (d, J = 16.4 Hz, 1 H, Hvinyl), 6.78–
6.87 (m, 4 H, Harom), 7.15 (dd, J = 1.6, 7.2 Hz, 1 H, Harom), 7.20
(dd, J = 1.7, 7.4 Hz, 1 H, Harom), 7.28 (d, J = 16.4 Hz, 1 H, Hvinyl),
7.34–7.38 (m, 2 H, Harom) ppm. 13C NMR (75 MHz, CDCl3): δ =
55.6 (CH3), 55.9 (CH3), 87.7 (Cq), 93.9 (Cq), 109.1 (CH), 110.7
(CH), 111.1 (CH), 112.9 (Cq), 120.6 (CH), 120.8 (CH), 125.6 (Cq),
126.9 (CH), 129.6 (2 CH), 133.6 (CH), 136.5 (CH), 157.1 (Cq),
C18H16O2 (264.32): calcd. C 81.79, H 6.10; found C 81.74, H 6.00.
(Z)-1-(2-Methoxyphenyl)-4-(4-methoxyphenyl)but-3-en-1-yne (1b):
1
Yellow oil (201 mg, 76%). H NMR (300 MHz, CDCl3): δ = 3.84
(s, 3 H, CH3), 3.95 (s, 3 H, CH3), 5.86 (d, J = 11.9 Hz, 1 H, Hvinyl),
6.62 (d, J = 11.9 Hz, 1 H, Hvinyl), 6.90–6.93 (m, 3 H, Harom), 6.96
(dd, J = 1.0, 7.5 Hz, 1 H, Harom), 7.31 (ddd, J = 1.7, 7.5, 8.3 Hz,
1 H, Harom), 7.45 (dd, J = 1.7, 7.5 Hz 1 H, Harom), 8.03 (d, J =
8.7 Hz, 2 H, Harom) ppm. 13C NMR (75 MHz, CDCl3): δ = 55.4
(CH3), 56.0 (CH3), 92.3 (Cq), 92.9 (Cq), 105.2 (CH), 110.7 (CH),
113.0 (Cq), 113.7 (2 CH), 120.7 (CH), 129.8 (CH), 129.9 (Cq), 130.5
(2 CH), 133.3 (CH), 137.8 (CH), 159.8 (Cq), 160.2 (Cq) ppm. IR
159.9 (C ) ppm. IR (neat): ν = 2933, 1593, 1485, 1434, 1241, 1119,
˜
q
1024 cm–1. MS (APCI+): m/z = 265.0 [M + H]+. C18H16O2
(264.32): calcd. C 81.79, H 6.10; found C 81.65, H 6.00.
(neat): ν = 1603, 1509, 1461, 1253, 1172, 1115, 1024 cm–1. MS
˜
(E)-1-(2-Methoxyphenyl)-4-(3,4-methylenedioxyphenyl)but-3-en-1-
(APCI+): m/z = 265.0 [M + H]+. C18H16O2 (264.32): calcd. C 81.79,
1
yne (1h): Yellow oil (245 mg, 88%). H NMR (300 MHz, CDCl3):
H 6.10; found C 81.74, H 6.05.
δ = 3.91 (s, 3 H, CH3), 5.98 (s, 2 H, CH2), 6.27 (d, J = 16.2 Hz, 1
H, Hvinyl), 6.78 (d, J = 8.0 Hz, 1 H, Harom), 6.85–7.00 (m, 5 H,
vinyl, arom.), 7.26–7.32 (m, 1 H, Harom), 7.44 (dd, J = 1.7, 7.5 Hz,
1 H, Harom) ppm. 13C NMR (75 MHz, CDCl3): δ = 56.0 (CH3),
87.8 (Cq), 93.2 (Cq), 101.4 (CH2), 105.3 (CH), 106.7 (CH), 108.6
(CH), 110.7 (CH), 112.8 (Cq), 120.6 (CH), 121.8 (CH), 129.7 (CH),
131.2 (Cq), 133.6 (CH), 140.8 (CH), 148.2 (Cq), 148.3 (Cq), 159.9
(E)-4-(4-Methoxyphenyl)-1-phenylbut-3-en-1-yne (1c): Yellow oil
(185 mg, 79%). 1H NMR (300 MHz, CDCl3): δ = 3.83 (s, 3 H,
CH3), 6.25 (d, J = 16.2 Hz, 1 H, Hvinyl), 6.88 (d, J = 8.7 Hz, 2 H,
Harom), 7.00 (d, J = 16.2 Hz, 1 H, Hvinyl), 7.31–7.33 (m, 3 H,
Harom), 7.37 (d, J = 8.7 Hz, 2 H, Harom), 7.45–7.48 (m, 2 H, Harom
)
ppm. 13C NMR (75 MHz, CDCl3): δ = 55.5 (CH3), 89.39 (Cq), 91.1
(Cq), 105.8 (CH), 114.3 (2 CH), 123.7 (Cq), 127.8 (2 CH), 128.1
(CH), 128.4 (2 CH), 129.3 (Cq), 131.6 (2 CH), 141.0 (CH), 160.2
(C ) ppm. IR (neat): ν = 1591, 1488, 1237, 1117, 1025, 925, 790,
˜
q
739 cm–1. MS (APCI+): m/z = 279.0 [M + H]+. C18H14O3 (278.30):
(C ) ppm. IR (neat): ν = 1023, 1175, 1251, 1441, 1487, 1509,
˜
q
calcd. C 77.68, H 5.07; found C 77.54, H 5.00.
1601 cm–1. MS (APCI+): m/z = 235.0 [M + H]+. C17H14O (234.29):
calcd. C 87.15, H 6.02; found C 87.01, H 5.93.
(E)-1-(2-Methoxyphenyl)-4-(2-naphthyl)but-3-en-1-yne (1i): Yellow
oil (230 mg, 81%). H NMR (300 MHz, CDCl3): δ = 3.93 (s, 3 H,
1
(Z)-1-(2-Ethoxycarbonylphenyl)-4-(4-methoxyphenyl)but-3-en-1-yne
CH3), 6.58 (d, J = 16.2 Hz, 1 H, Hvinyl), 6.89–6.97 (m, 2 H, Harom),
7.23 (d, J = 16.2 Hz, 1 H, Hvinyl), 7.28–7.34 (m, 1 H, Harom), 7.46–
7.49 (m, 3 H, Harom, Hnaph), 7.62 (dd, J = 1.6, 8.6 Hz, 1 H, Hnaph),
7.78–7.84 (m, 4 H, Hnaph) ppm. 13C NMR (75 MHz, CDCl3): δ =
56.0 (CH3), 88.6 (Cq), 93.3 (Cq), 108.9 (CH), 110.7 (CH), 112.7
(Cq), 120.7 (CH), 122.9 (CH), 126.5 (CH), 126.6 (CH), 127.0 (CH),
127.8 (CH), 128.4 (CH), 128.6 (CH), 129.9 (CH), 133.6 (Cq), 133.7
1
(1d): Yellow oil (254 mg, 83%). H NMR (300 MHz, CDCl3): δ =
1.36 (t, J = 7.1 Hz, 3 H, CH3), 3.83 (s, 3 H, CH3), 4.37 (q, J =
7.1 Hz, 2 H, CH2), 5.87 (d, J = 11.9 Hz, 1 H, Hvinyl), 6.67 (d, J =
11.9 Hz, 1 H, Hvinyl), 6.91 (d, J = 8.8 Hz, 2 H, Harom), 7.34–7.40
(m, 1 H, Harom), 7.46–7.51 (m, 1 H, Harom), 7.59 (dd, J = 1.2,
7.7 Hz, 1 H, Harom), 7.94–7.99 (m, 3 H, Harom) ppm. 13C NMR
(75 MHz, CDCl3): δ = 14.3 (CH3), 55.4 (CH3), 61.3 (CH2), 93.6
(Cq), 94.3 (Cq), 105.0 (CH), 113.8 (2 CH), 124.1 (Cq), 127.9 (CH),
129.6 (Cq), 130.5 (3 CH), 131.7 (CH), 132.0 (Cq), 134.1 (CH), 138.8
(CH), 134.1 (2 C ), 141.2 (CH), 160.0 (C ) ppm. IR (neat): ν =
˜
q
q
1589, 1490, 1462, 1433, 1270, 1118, 1025 cm–1. MS (APCI+): m/z
= 285.0 [M + H]+. C21H16O (284.35): calcd. C 88.70, H 5.67; found
C 88.57, H 5.56.
(CH), 159.9 (C ), 166.4 (C ) ppm. IR (neat): ν = 1721, 1604, 1510,
˜
q
q
1248, 1172, 1079, 1031 cm–1. MS (APCI+): m/z = 307.0 [M + H]+.
C20H18O3 (306.36): calcd. C 78.41, H 5.92; found C 78.35, H 5.87.
(E)-4-(4-Chlorophenyl)-1-(2-methoxyphenyl)but-3-en-1-yne (1j): Yel-
low oil (230 mg, 86%). H NMR (300 MHz, CDCl3): δ = 3.91 (s,
1
(E)-1-(4-Methoxyphenyl)non-1-en-3-yne (1e): Yellow oil (185 mg,
1
81%). H NMR (300 MHz, CDCl3): δ = 0.91 (t, J = 7.1 Hz, 3 H, 3 H, CH3), 6.42 (d, J = 16.2 Hz, 1 H, Hvinyl), 6.88–6.96 (m, 2 H,
CH3), 1.31–1.46 (m, 4 H, 2 CH2), 1.57 (m, 2 H, CH2), 2.33–2.38 Harom), 7.00 (d, J = 16.2 Hz, 1 H, Hvinyl), 7.27–7.36 (m, 5 H,
(m, 2 H, CH2), 3.81 (s, 3 H, CH3), 6.02 (dt, J = 2.2, 16.2 Hz, 1 H, Harom), 7.43–7.46 (m, 1 H, Harom) ppm. 13C NMR (75 MHz,
Hvinyl), 6.79–6.86 (m, 3 H, Hvinyl, Harom), 7.30 (d, J = 8.5 Hz, 2 H, CDCl3): δ = 56.0 (CH3), 88.8 (Cq), 92.7 (Cq), 109.3 (CH), 110.7
Harom) ppm. 13C NMR (75 MHz, CDCl3): δ = 14.1 (CH3), 19.8 (CH), 112.5 (Cq), 120.7 (CH), 127.6 (2 CH), 129.1 (2 CH), 130.0
(CH2), 22.4 (CH2), 28.7 (CH2), 31.3 (CH2), 55.4 (CH3), 80.0 (Cq), (CH), 133.6 (CH), 134.3 (Cq), 135.1 (Cq), 139.7 (CH), 160.0 (Cq)
92.3 (Cq), 106.6 (CH), 114.2 (2 CH), 127.4 (2 CH), 129.6 (Cq), ppm. IR (neat): ν = 1591, 1489, 1432, 1240, 1122, 1026 cm–1. MS
˜
139.6 (CH), 159.9 (C ) ppm. IR (neat): ν = 2928, 1605, 1510, 1463, (APCI+): m/z = 269.0 [[M + H]+ Cl35], 271.0 [[M + H]+ Cl37].
˜
q
1246, 1174, 1033 cm–1. MS (APCI+): m/z = 229.0 [M + H]+.
C17H13ClO (268.74): calcd. C 75.98, H, 4.88; found C 75.89, H,
5.01.
C16H20O (228.33): calcd. C 84.16, H 8.83; found C 84.12, H 8.77.
Eur. J. Org. Chem. 2010, 725–731
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
729

A. Tikad, A. Hamze, O. Provot, J.-D. Brion, M. Alami
FULL PAPER
(E)-4-(4-Acetylphenyl)-1-(2-methoxyphenyl)but-3-en-1-yne
(1k): (APCI+): m/z = 227.0 [M + H]+. C16H18O (226.31): calcd. C 84.91,
1
Yellow oil (225 mg, 84%). H NMR (300 MHz, CDCl3): δ = 2.59
(s, 3 H, CH3), 3.91 (s, 3 H, CH3), 6.56 (d, J = 16.2 Hz, 1 H, Hvinyl),
6.88–6.96 (m, 2 H, Harom), 7.06 (d, J = 16.2 Hz, 1 H, Hvinyl), 7.28–
7.34 (m, 1 H, Harom), 7.44 (dd, J = 1.7, 7.7 Hz, 1 H, Harom), 7.48
(d, J = 8.3 Hz, 2 H, Harom), 7.91 (d, J = 8.3 Hz, 2 H, Harom) ppm.
13C NMR (75 MHz, CDCl3): δ = 26.7 (CH3), 55.9 (CH3), 90.1 (Cq),
92.7 (Cq), 110.8 (CH), 111.6 (CH), 112.4 (Cq), 120.7 (CH), 126.4
(2 CH), 129.0 (2 CH), 130.2 (CH), 133.7 (CH), 136.7 (Cq), 139.6
H 8.02; found C 84.65, H 7.74.
1-(2-Methoxyphenyl)but-3-en-1-yne (1p): Yellow oil (82 mg, 52%).
1H NMR (300 MHz, CDCl3): δ = 3.89 (s, 3 H, CH3), 5.53 (dd, J
= 2.1, 11.1 Hz, 1 H, Hvinyl), 5.75 (dd, J = 2.1, 17.5 Hz, 1 H, Hvinyl),
6.08 (dd, J = 11.1, 17.5 Hz, 1 H,Hvinyl), 6.86–6.93 (m, 2 H, Harom),
7.26–7.32 (m, 1 H, Harom), 7.42 (dd, J = 1.6, 7.5 Hz, 1 H, Harom
)
ppm. 13C NMR (75 MHz, CDCl3): δ = 55.9 (CH3), 86.4 (Cq), 92.3
(Cq), 110.7 (CH), 112.4 (Cq), 117.6 (CH), 120.6 (CH), 126.8 (CH2),
(CH), 141.1 (C ), 160.1 (C ), 197.4 (C ) ppm. IR (neat): ν = 2195,
˜
q
q
q
129.9 (CH), 133.7 (CH), 160.0 (C ) ppm. IR (neat): ν = 1595, 1491,
˜
q
1676, 1598, 1490, 1357, 1256, 1180 cm–1. MS (APCI+): m/z = 277.0
[M + H]+. C19H16O2 (276.33): calcd. C 82.58, H 5.84; found C
82.55, H 5.75.
1434, 1263, 1181, 1119, 1021 cm–1. MS (APCI+): m/z = 159.0 [M
+ H]+. C11H10O (158.20): calcd. C 83.51, H 6.37; found C 83.30,
H 6.15.
(E)-4-(4-Formylphenyl)-1-(2-methoxyphenyl)but-3-en-1-yne
(1l):
(Z)-Ethyl 3-(4-methoxyphenyl)-2-(phenylethynyl)but-2-enoate (1q):
Yellow oil (150 mg, 77%). H NMR (300 MHz, CDCl3): δ = 1.09
1
1
Yellow oil (186 mg, 71%). H NMR (300 MHz, CDCl3): δ = 3.91
(s, 3 H, CH3), 6.60 (d, J = 16.2 Hz, 1 H, Hvinyl), 6.89–6.96 (m, 2
H, Harom), 7.07 (d, J = 16.2 Hz, 1 H, Hvinyl), 7.29–7.35 (m, 1 H,
Harom), 7.45 (dd, J = 1.3, 7.5 Hz, 1 H, Harom), 7.55 (d, J = 8.1 Hz,
2 H, Harom), 7.84 (d, J = 8.1 Hz, 2 H, Harom), 9.98 (s, 1 H, CHO)
ppm. 13C NMR (75 MHz, CDCl3): δ = 56.0 (CH3), 90.6 (Cq), 92.6
(Cq), 110.8 (CH), 112.3 (CH), 120.7 (CH), 126.8 (2 CH), 130.3 (3
CH), 133.7 (CH), 136.0 (Cq), 139.5 (CH), 142.4 (Cq), 160.1 (Cq),
(t, J = 7.1 Hz, 3 H, CH3), 2.44 (s, 3 H, CH3), 3.82 (s, 3 H, CH3),
4.07 (q, J = 7.1 Hz, 2 H, CH2), 6.87 (d, J = 8.6 Hz, 2 H, Harom),
7.19 (d, J = 8.6 Hz, 2 H, Harom), 7.32–7.34 (m, 3 H, HPh), 7.49–
7.52 (m, 2 H, HPh) ppm. 13C NMR (75 MHz, CDCl3): δ = 14.0
(CH3), 24.4 (CH3), 55.4 (CH3), 61.2 (CH2), 86.0 (Cq), 95.9 (Cq),
113.7 (2 CH), 123.4 (Cq), 128.5 (5CH), 131.6 (2 CH), 133.7 (Cq),
154.6 (C ), 159.8 (C ), 166.5 (C ). ppm. IR (neat): ν = 1719, 1605,
˜
q
q
q
1510, 1324, 1248, 1178, 1109, 1031, 832 cm–1. MS (APCI+): m/z =
321.0 [M + H]+. C21H20O3 (320.38): calcd. C 78.73, H 6.29; found
C 78.51, H 6.10.
191.1 (CH) ppm. IR (neat): ν = 1693, 1597, 1490, 1434, 1212, 1165,
˜
1024 cm–1. MS (APCI+): m/z = 263.0 [M + H]+. C18H14O2
(262.30): calcd. C 82.42, H 5.38; found C 82.41, H 5.32.
(E)-1-(2-Methoxyphenyl)-4-(3-nitrophenyl)but-3-en-1-yne (1m): Yel-
1
low oil (198 mg, 71%). H NMR (300 MHz, CDCl3): δ = 3.91 (s,
Acknowledgments
3 H, CH3), 6.58 (d, J = 16.2 Hz, 1 H, Hvinyl), 6.89–6.96 (m, 2 H,
Harom), 7.07 (d, J = 16.2 Hz, 1 H, Hvinyl), 7.29–7.35 (m, 1 H,
Harom), 7.45 (dd, J = 1.2, 7.6 Hz, 1 H, Harom), 7.47–7.53 (m, 1 H,
Harom), 7.70 (d, J = 7.8 Hz, 1 H, Harom), 8.09–8.13 (m, 1 H, Harom),
8.25 (s, 1 H, Harom) ppm. 13C NMR (75 MHz, CDCl3): δ = 55.9
(CH3), 90.3 (Cq), 92.0 (Cq), 110.8 (CH), 112.0 (CH), 112.2 (Cq),
120.7 (CH), 120.9 (CH), 122.9 (CH), 129.8 (CH), 130.3 (CH), 131.9
(CH), 133.7 (CH), 138.1 (CH), 138.3 (Cq), 148.8 (Cq), 160.1 (Cq)
The Centre National de la Recherche Scientifique (CNRS) is grate-
fully acknowledged for financial support of this research. We thank
the Association de Recherche sur le Cancer (ARC) for a post-doc-
toral grant to A.T.
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˜
MS (APCI+): m/z = 280.0 [M + H]+. C17H13NO3 (279.29): calcd.
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(E)-1-(2-Methoxyphenyl)-4-(3-thienyl)but-3-en-1-yne (1n): Yellow
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1
CH3), 6.29 (d, J = 16.1 Hz, 1 H, Hvinyl), 6.88–6.95 (m, 2 H, Harom),
7.06 (d, J = 16.1 Hz, 1 H, Hvinyl), 7.25–7.32 (m, 4 H, Harom), 7.44
(dd, J = 1.7, 7.5 Hz, 1 H, Harom) ppm. 13C NMR (75 MHz,
CDCl3): δ = 56.0 (CH3), 88.1 (Cq), 93.0 (Cq), 108.4 (CH), 110.7
(CH), 112.8 (Cq), 120.6 (CH), 123.6 (CH), 124.6 (CH), 126.6 (CH),
129.8 (CH), 133.6 (CH), 135.1 (CH), 139.5 (Cq), 159.9 (Cq) ppm.
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˜
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22.4 (CH2), 35.0 (CH2), 55.9 (CH3), 87.6 (Cq), 93.4 (Cq), 109.2
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© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Received: October 7, 2009
Published Online: December 17, 2009
Eur. J. Org. Chem. 2010, 725–731
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
731