Carbonylative Stille coupling reactions of benzyl chlorides with allyltributylstannane catalyzed by palladium nanoparticles

Article abstract of DOI:10.1016/j.tet.2014.07.002

The carbonylative Stille coupling reaction of benzyl chlorides with allyltributylstannane was successfully conducted by using palladium nanoparticles as the catalyst under phosphine ligand-free conditions. The corresponding α,β-unsaturated ketone products

Full text of DOI:10.1016/j.tet.2014.07.002

Tetrahedron xxx (2014) 1e6
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Tetrahedron
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Carbonylative Stille coupling reactions of benzyl chlorides with
allyltributylstannane catalyzed by palladium nanoparticles
,
b
,
a,
Jian Sun a, Xiujuan Feng a , Ziran Zhao , Yoshinori Yamamoto c, Ming Bao a
*
*
a State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116023, China
b Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun 130021, China
c WPI-AIMR (WPI-Advanced Institute for Materials Research), Tohoku University, Sendai 980-8577, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
The carbonylative Stille coupling reaction of benzyl chlorides with allyltributylstannane was successfully
conducted by using palladium nanoparticles as the catalyst under phosphine ligand-free conditions. The
corresponding a,b-unsaturated ketone products were obtained in good to excellent yields.
Received 1 April 2014
Received in revised form 26 June 2014
Accepted 1 July 2014
Ó 2014 Published by Elsevier Ltd.
Available online xxx
Keywords:
Palladium nanoparticles
Carbon monoxide
Carbonylative coupling
1. Introduction
Palladium-catalyzed carbonylative coupling reactions have be-
come a straightforward and efficient method for the synthesis of
carbonyl group-containing compounds.1 Over the past three de-
cades, many types of palladium-catalyzed carbonylative coupling
reactions, including carbonylative Heck coupling,2 carbonylative
Sonogashira coupling,3 carbonylative Suzuki coupling,4 carbon-
ylative Stille coupling,5 carbonylative Negishi coupling,6 and car-
bonylative Hiyama coupling7 have been developed for synthesis of
carbonyl group-containing compounds. Recently, we have reported
the palladium-catalyzed carbonylative Stille coupling reactions of
ð1Þ
benzyl chlorides with allyltributylstannane to produce
b,g-un-
ð2Þ
saturated ketones for the first time (Eq. 1).8 The above mentioned
palladium-catalyzed carbonylative coupling reactions usually in-
volved the use of phosphine ligands. As is well known, the use of
phosphine ligands is disadvantageous as it often leads to air/
moisture sensitivity, tedious work-up procedures and high work-up
costs.9 Therefore, a phosphine ligand-free method for the synthesis
of carbonyl group-containing compounds is desirable.
In the course of our research on palladium nanoparticles-
catalyzed three-component reactions,10 we found that the car-
bonylative Stille coupling reaction of benzyl chlorides with allyl-
tributylstannane can also be performed by utilizing palladium
nanoparticles as the catalyst under phosphine ligand-free
* Corresponding authors. Tel.: þ86 411 84986181; fax: þ86 411 84986180; e-mail
addresses: engxiujuan@dlut.edu.cn (X. Feng), dczhaoziran@126.com (Z. Zhao).
http://dx.doi.org/10.1016/j.tet.2014.07.002
0040-4020/Ó 2014 Published by Elsevier Ltd.
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2
J. Sun et al. / Tetrahedron xxx (2014) 1e6
conditions to produce
a
,
b-unsaturated ketones (Eq. 2). The results
2.5 equiv TOAB was employed (entry 8, 81%; entry 9, 67%). The
are reported in this paper.
solvents were finally screened using Pd(acac)2 and TOAB as the
precatalyst and additive, respectively. Nonpolar (toluene) and polar
[THF, MeCN, and N,N-dimethyl formamide (DMF)] solvents were
examined (entries 3 and 10e12). THF proved to be the best solvent
(entry 3). Further studies revealed that the yield of product 2a
decreased with a change in CO pressure (entry 13: 1 MPa CO, 72%;
entry 14: 0.1 MPa CO, 56%). The yield of product 2a decreased (68%)
when the reaction time was shortened (12 h, entry 15). Therefore,
the subsequent palladium-catalyzed carbonylative couplings of
various benzyl chlorides with allyltributylstannane were per-
formed in the presence of Pd(acac)2 as the precatalyst and using
TOAB (1.9 equiv) as the additive under 0.5 MPa of CO pressure in
THF for 24 h.
2. Result and discussion
In the initial studies, the reaction of benzyl chloride (1a) with
allyltributylstannane in the presence of carbon monoxide (CO) was
chosen as a model to optimize the reaction conditions. The opti-
mization included the selection of the most suitable palladium
catalyst source, additive, and solvent. The results are summarized
in Table 1. Precatalysts Pd2(dba)3, PdCl2, and Pd(acac)2 were initially
tested in tetrahydrofuran (THF) at 50 ꢀC in the presence of tet-
raoctylammonium bromide (TOAB). A relatively high yield was
obtained using Pd(II) salts as precatalysts, and Pd(acac)2 proved to
be the best precatalyst (entries 2 and 3 vs entry 1). These results
indicated that a Pd(0) species generated in situ possessed higher
catalytic activity than Pd2(dba)3. The Stille coupling and allylative
dearomatization products were not observed.11
Table 1
Reaction condition screeninga
Entry
Catalyst
Additive
Solvent
Yield (%)b
Z/Ec
1
2
3
4
5
6
Pd2(dba)3
PdCl2
TOAB
TOAB
TOAB
None
TBAF
TBAC
TBAB
TOAB
TOAB
TOAB
TOAB
TOAB
TOAB
TOAB
TOAB
THF
THF
THF
THF
THF
THF
THF
THF
63
67
94
NRd
31
48
87
81
67
83
68
45
72
56
68
11/89
9/91
Fig. 1. EDX analysis of palladium nanoparticles.
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
Pd(acac)2
19/81
NRd
Table 2 shows the results of palladium-catalyzed carbonylative
Stille coupling of various benzyl chlorides with allyltributyl-
stannane. High yields similar to that of 2a were observed when 4-
fluorobenzyl chloride (1b), 4-chlorobenzyl chloride (1c), and 4-
bromobenzyl chloride (1d) were employed under optimized re-
action conditions (entries 2e4 vs entry 1, 90%e92%). Notably, the Cl
and Br atoms linked to the benzene ring were maintained in the
structures of the products 2c and 2d under the carbonylative cou-
pling reaction conditions; these atoms provided opportunities for
the further functionalization of these compounds. The reactions of
2-dichlorobenzyl chloride (1e) and 2,4-dichlorobenzyl chloride (1f)
with allyltributylstannane also proceeded smoothly to produce the
desired carbonylative Stille coupling products 2e and 2f in good
yields (entries 5 and 6; 88% and 82%, respectively). As expected, the
reaction of 4-methylbenzyl chloride (1g) that bears an electron-
donating group methyl (Me) on the para position provided a high
yield of product 2g (entry 7, 91%). Reactions of benzyl chlorides
1hej that bear a methoxy (MeO) group on the ortho, meta or para
positions provided excellent yields of products 2hej (entries 8e10,
93%e95%). These results indicate that the reactivities of the benzyl
chlorides were not influenced by substituent steric effects. Finally,
chloromethyl naphthalene substrates 1k and 1l were utilized in
this type of carbonylative coupling reaction. Products 2k and 2l
were obtained in the same yield of 94% (entries 11 and 12).
Transmission electron microscopy (TEM) was performed to in-
vestigate the reason for the high activity of the palladium catalyst
system (Pd/TOAB) in this type of carbonylative coupling. The results
are shown in Fig. 2. As expected, the TEM image shows the presence
of (1.97ꢁ0.5) nm-sized palladium nanoparticles in the reaction
mixture. These results reveal that the additive TOAB acted as
a stabilizer to disperse the palladium nanoparticles generated in
situ by reducing Pd(acac)2 with allyltributylstannane.12 It has been
demonstrated that a metallic core in the coreeshell Pd nano-
particles is surrounded by a stabilizing shell composed of a tetra-
butylammonium ion monolayer surrounded by Brꢂ and [PdBr4]2ꢂ
species, which counterbalance the positive charges in the shell.13
The palladium nanoparticles generated in situ is known to exhibit
12/78
14/76
10/90
13/87
11/89
9/91
9/91
11/89
8/92
7
8e
9f
THF
10
11
12
13g
14h
15i
Toluene
MeCN
DMF
THF
THF
THF
15/85
10/90
a
Reaction conditions: benzyl chloride (1a,
3 mmol), allytributylstannane
(3.3 mmol), CO (0.5 MPa), Pd catalyst (5 mol %), additive (1.9 equiv), and solvent
(20 mL) at 50 ꢀC for 24 h.
b
Isolated total yield of cis- and trans-isomers; the cis- and trans-isomers were
separated through silica gel chromatography.
c
The ratio of cis-isomer to trans-isomer.
No reaction.
1.4 equiv TOAB was used.
2.5 equiv TOAB was used.
The reaction was performed under 1 MPa of CO.
The reaction was performed under 0.1 MPa of CO.
The reaction was performed for 12 h.
d
e
f
g
h
i
The use of a quaternary ammonium salt as an additive was
necessary to avoid palladium black generation. Both no reaction
and the generation of palladium black were observed in the ab-
sence of a stabilizer such as TOAB, which suggested that the target
reaction could not proceed in the presence of Pd black under
phosphine ligand-free conditions. No generation of Pd/Sn alloy was
confirmed by energy-dispersive X-ray (EDX) analysis of palladium
nanoparticles (Fig. 1). Thus, the quaternary ammonium salts were
screened using Pd(acac)2 as the precatalyst in THF (entries 3 and
5e7). Among the tested quaternary ammonium salts [TOAB, tet-
rabutylammonium fluoride (TBAF), tetrabutylammonium chloride
(TBAC), and tetrabutylammonium bromide (TBAB)], the use of
TOAB as additive produced the highest yield of desired product 2a
(entry 3, 94%). The reaction yield was also influenced by the amount
of TOAB utilized. Decreased yield of 2a was obtained when 1.4 or
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J. Sun et al. / Tetrahedron xxx (2014) 1e6
3
Table 2
Palladium-catalyzed carbonylative coupling of benzyl chlorides with
allyltributylstannanea
Entry
1
Benzyl chloride 1
Product 2
Yield Z/Ec
(%)b
1a
1b
1c
1d
1e
1f
2a 94
19/81
24/76
22/78
18/82
22/78
13/87
20/80
18/82
16/84
Fig. 2. TEM image and size distribution of palladium nanoparticles.
higher catalytic activity than
a
relative molecular catalyst.14
Therefore, the high activity of the palladium catalyst system
employed can be ascribed to the formation of palladium nano-
particles. However, the Pd nanoparticles could not be separated and
reused due to their small size. A similar conversion (86%) was ob-
served in the carbonylative Stille coupling reaction of benzyl
chloride with allyltributylstannane when the pre-formed Pd
nanoparticles were used as the catalyst.
2
3
4
5
6
7
8
9
2b 92
2c
90
2d 90
3. Conclusion
In summary, we have developed a palladium nanoparticles-
based catalyst system for a Stille carbonylation coupling of benzyl
chlorides with allyltributylstannane in the absence of phosphine
ligands. The mild reaction conditions (low CO pressure and tem-
perature), experimental simplicity, and broad substrate scope are
features of the novel and general catalytic method proposed in this
paper. Further studies focusing on the recycling use of palladium
nanoparticles catalyst and the extension of the reaction scope using
substituted allyltin reagents are currently underway.
2e 88
2f
82
1g
1h
1i
2g 91
4. Experimental section
4.1. General information
2h 95
All reactions were carried out under a nitrogen atmosphere
unless otherwise noted. Solvents were purified by standard tech-
niques without special instructions. 1H and 13C NMR spectra were
recorded on either a Varian Inova-400 spectrometer or a Bruker
Avance II-400 spectrometer (400 MHz for 1H, 100 MHz for 13C);
CDCl3 and TMS were used as a solvent and an internal standard,
respectively. The chemical shifts are reported in parts per million
2i
94
10
11
12
a
1j
2g 93
24/76
15/85
17/83
downfield (d) from TMS, the coupling constants J are given in Hertz.
The peak patterns are indicated as follows: s, singlet; d, doublet; t,
triplet; q, quartet; m, multiplet. IR spectra were recorded on
a NEXUS FT-IR spectrometer. High resolution mass spectra were
recorded on either a Q-TOF mass spectrometry or a GC-TOF mass
spectrometry. Transmission electron microscopy (TEM) was per-
formed on a Tecnai G2 microscope operating at 120 kV.
After the carbonylative coupling reaction of benzyl chloride
with allyltributylstannane was performed for 24 h at optimized
reaction conditions, the resultant mixture was used for TEM de-
termination. TLC was carried out on SiO2 (silica gel 60 F254 Merck),
and the spots were located with UV light, iodoplatinate reagent or
1% aqueous KMnO4. Flash chromatography was carried out on SiO2
(silica gel 60, 200e300 mesh) or basic Al2O3 (Al2O3 90,
100e200 mesh). Unless otherwise noted, carbon monoxide
(99.999%) was used without further purification. The starting ma-
terials 1aec, 1eeg, 1kel, and allyltributylstannane are commer-
cially available. The starting material 1d,15 1h,16 1i,17 and 1j18
appeared in the literature.
1k
1l
2k 94
2l
94
Reaction conditions: benzyl chloride (1,
3 mmol), allyltributylstanane
(3.3 mmol), CO (0.5 MPa), Pd(acac)2 (5 mol %), TOAB (1.9 equiv), and THF (20 mL) at
50 ꢀC for 24 h.
b
Isolated total yield of cis- and trans-isomers; the cis- and trans-isomers were
separated through silica gel chromatography.
c
The ratio of the cis-isomer to trans-isomer.
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4
J. Sun et al. / Tetrahedron xxx (2014) 1e6
4.2. Representative experimental procedure for the carbon-
ylative coupling reaction
(100 MHz, CDCl3): d 196.9, 144.3, 133.1, 133.0, 131.0, 128.9, 128.5,
46.7, 18.5; IR (neat): 2913, 1722, 1692, 1670, 1598, 1492, 1441, 1408,
1292, 1187, 970, 840, 721 cmꢂ1; HRMS (EI, m/z) calcd for C11H11ClO:
194.0498 [Mþ], found: 194.0494.
A 50 mL oven dried autoclave vessel containing a stir bar was
charged with Pd(acac)2 (45.7 mg, 0.15 mmol) and TOAB (3.1 g,
5.7 mmol). Benzyl chloride (379.7 mg, 3.0 mmol), allyltributyl-
stannane (1.1 g, 3.3 mmol), and dry THF 20 mL were added with
syringe under a N2 atmosphere, respectively. After purging the
autoclave with CO three times, the sealed autoclave was pres-
surized to 0.5 MPa with CO. The reaction mixture was stirred at
50 ꢀC for 24 h, then the autoclave was cooled to room temper-
ature and the remaining CO was vented slowly. The resultant
mixture was evaporated in vacuo to give the crude product,
which was then purified via silica gel chromatography (eluent:
ethyl acetate/petroleum ether¼1:20) to afford (Z)-1-
phenylpent-3-en-2-one (2aZ) and (E)-1-phenylpent-3-en-2-
one (2aE) in 18% and 76% yields, respectively (total yield: 94%,
Z/E: 19/81).
4.3.7. (Z)-1-(4-Bromophenyl)pent-3-en-2-one (2dZ). Light yellow
oil (115.7 mg, 16% yield). 1H NMR (400 MHz, CDCl3):
d 7.45 (d,
J¼8.4 Hz, 2H), 7.08 (d, J¼8.4 Hz, 2H), 6.29e6.16 (m, 2H), 3.69 (s, 2H),
2.11 (dd, J¼6.8, 1.2 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d 198.0,
145.1, 133.5, 131.8, 131.4, 126.7, 121.1, 50.6, 16.2; IR (neat): 3027,
2924, 2026, 1900, 1690, 1619, 1488, 1365, 1204, 1069, 1012, 968, 803,
744, 709 cmꢂ1; HRMS (EI, m/z) calcd for C11H11BrO: 237.9993 and
239.9973 [Mþ], found: 237.9998 and 239.9984.
4.3.8. (E)-1-(4-Bromophenyl)pent-3-en-2-one
solid (526.9 mg, 74% yield); mp: 40e42 ꢀC. 1H NMR (400 MHz,
CDCl3):
7.44 (d, J¼8.4 Hz, 2H), 7.07 (d, J¼8.4 Hz, 2H), 6.98e6.89 (m,
1H), 6.16 (dd, J¼15.6, 1.6 Hz, 1H), 3.76 (s, 2H), 1.89 (dd, J¼6.8, 1.6 Hz,
3H); 13C NMR (100 MHz, CDCl3):
196.8, 144.3, 133.6, 131.8, 131.3,
(2dE). Yellowish
d
d
4.3. Characterization of compounds
130.9, 121.0, 46.7, 18.5; IR (KBr): 3012, 2965, 2939, 1922, 1673, 1630,
1488, 1399, 1290, 1189, 966, 837, 715 cmꢂ1; HRMS (EI, m/z) calcd for
4.3.1. (Z)-1-Phenylpent-3-en-2-one (2aZ).19 Light yellow oil
C
11H11BrO: 237.9993 and 239.9973 [Mþ], found: 237.9994 and
239.9992.
(85.8 mg, 18% yield). 1H NMR (400 MHz, CDCl3):
d
7.32 (dd, J¼7.6,
7.6 Hz, 2H), 7.26 (d, J¼7.2 Hz, 1H), 7.22 (dd, J¼7.4, 7.4 Hz, 2H),
6.26e6.15 (m, 2H), 3.73 (s, 2H), 2.11 (d, J¼4.8 Hz, 3H).
4.3.9. (Z)-1-(2-Chlorophenyl)pent-3-en-2-one (2eZ).8 Light yellow
oil (112.7 mg, 19% yield). 1H NMR (400 MHz, CDCl3):
d 7.42e7.35 (m,
4.3.2. (E)-1-Phenylpent-3-en-2-one (2aE).20 Light yellow oil
1H), 7.25e7.17 (m, 3H), 6.27e6.19 (m, 2H), 3.89 (s, 2H), 2.12 (d,
J¼6.0 Hz, 3H).
(365.7 mg, 76% yield). 1H NMR (400 MHz, CDCl3):
d
7.32 (dd, J¼7.4,
7.4 Hz, 2H), 7.26 (d, J¼7.2 Hz, 1H), 7.21 (dd, J¼6.2, 6.2 Hz, 2H),
6.98e6.88 (m,1H), 6.17 (dd, J¼15.6,1.6 Hz,1H), 3.81 (s, 2H),1.87 (dd,
J¼6.8, 1.6 Hz, 3H).
4.3.10. (E)-1-(2-Chlorophenyl)pent-3-en-2-one (2eE).8 Light yellow
oil (399.6 mg, 69% yield). 1H NMR (400 MHz, CDCl3):
d 7.40e7.36
(m, 1H), 7.25e7.19 (m, 3H), 7.04e6.92 (m, 1H), 6.21 (dd, J¼15.6,
4.3.3. (Z)-1-(4-Fluorophenyl)pent-3-en-2-one (2bZ). Light yellow
1.6 Hz, 1H), 3.97 (s, 2H), 1.91 (d, J¼6.8, 1.6 Hz, 3H).
oil (118.0 mg, 22% yield). 1H NMR (400 MHz, CDCl3):
d 7.18e7.14
(m, 2H), 7.01 (dd, J¼8.6, 8.6 Hz, 2H), 6.28e6.13 (m, 2H), 3.70 (s,
4.3.11. (Z)-1-(2,4-Dichlorophenyl)pent-3-en-2-one (2fZ). Light yel-
2H), 2.11 (d, J¼5.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d
198.6,
low oil (72.9 mg, 11% yield). 1H NMR (400 MHz, CDCl3):
d 7.40 (d,
1
3
162.1 (d, JCF¼243.3 Hz), 144.9, 131.2 (d, JCF¼7.8 Hz), 130.3(d,
J¼8.4 Hz, 1H), 7.31 (d, J¼1.6 Hz, 1H), 7.04 (dd, J¼8.0, 2.0 Hz, 1H),
4JCF¼2.4 Hz), 126.7, 115.6 (d, JCF¼21.3 Hz), 50.4, 16.2; IR (neat):
6.32e6.17 (m, 2H), 3.70 (s, 2H), 2.13 (dd, J¼7.0, 1.6 Hz, 3H); 13C NMR
2
3042, 2918, 1723, 1691, 1626, 1510, 1440, 1223, 1190, 1016, 971, 825,
712 cmꢂ1; HRMS (EI, m/z) calcd for C11H11FO: 178.0794 [Mþ],
found: 178.0797.
(100 MHz, CDCl3): d 197.3, 145.6, 134.7, 132.7, 131.6, 131.2, 130.6,
129.1, 126.5, 50.0, 16.3; IR (neat): 3029, 2918, 2851, 1693, 1623, 1560,
1472, 1437, 1132, 1076, 969, 900, 819, 748 cmꢂ1; HRMS (EI, m/z)
calcd for C11H10Cl2O: 228.0109 [Mþ], found: 228.0101.
4.3.4. (E)-1-(4-Fluorophenyl)pent-3-en-2-one (2bE). Light yellow
oil (373.5 mg, 70% yield). 1H NMR (400 MHz, CDCl3):
d
7.16 (dd,
4.3.12. (E)-1-(2,4-Dichlorophenyl)pent-3-en-2-one (2fE). Light yel-
J¼8.6, 5.6 Hz, 2H), 7.01 (dd, J¼8.6, 8.6 Hz, 2H), 6.98e6.89 (m, 1H),
low oil (488.0 mg, 71% yield). 1H NMR (400 MHz, CDCl3):
d 7.37 (d,
6.17 (dd, J¼15.6, 1.6 Hz, 1H), 3.79 (s, 2H), 1.90 (dd, J¼6.8, 1.6 Hz,
J¼8.0 Hz, 1H), 7.29 (d, J¼2.0 Hz, 1H), 7.03 (dd, J¼8.0, 2.0 Hz, 1H),
3H); 13C NMR (100 MHz, CDCl3):
d
197.2, 163.1 (d, 1JCF¼275.2 Hz),
7.00e6.90 (m, 1H), 6.20e6.13 (m, 1H), 3.78 (s, 2H), 1.91 (dd, J¼6.8,
144.0, 131.1 (d, 3JCF¼7.8 Hz), 130.3 (d, 4JCF¼2.6 Hz), 129.0, 115.6 (d,
1.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d 196.2, 144.7, 134.8, 132.6,
2JCF¼21.3 Hz), 46.5, 16.5; IR (neat): 3041, 2956, 2924, 2854, 1726,
131.6, 131.1, 131.0, 130.6, 129.2, 46.1, 18.6; IR (neat): 3070, 3053,
2941, 1943, 1691, 1627, 1561, 1472, 1260, 1033, 964, 836, 752,
677 cmꢂ1; HRMS (EI, m/z) calcd for C11H10Cl2O: 228.0109 [Mþ],
found: 228.0105.
1694, 1509, 1443, 1376, 1288, 1223, 1073, 1017, 970, 823, 716 cmꢂ1
;
HRMS (EI, m/z) calcd for
C
11H11FO: 178.0794 [Mþ], found:
178.0797.
4.3.5. (Z)-1-(4-Chlorophenyl)pent-3-en-2-one (2cZ). Light yellow
oil (115.3 mg, 20% yield). 1H NMR (400 MHz, CDCl3):
7.30 (d,
4.3.13. (Z)-1-(4-Methylphenyl)pent-3-en-2-one (2gZ). Light yellow
d
oil (95.0 mg, 18% yield). 1H NMR (400 MHz, CDCl3):
d
7.15e7.07 (m,
4H), 6.21e6.15 (m, 2H), 3.61 (s, 2H), 2.32 (s, 3H), 2.10 (dd, J¼6.8,
3.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
199.1, 144.4, 136.6, 131.5,
J¼8.0 Hz, 2H), 7.14 (d, J¼8.0 Hz, 2H), 6.29e6.17 (m, 2H), 3.71 (s,
2H), 2.11 (d, J¼6.8 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d
198.2,
d
145.1, 133.0, 131.0, 128.9, 126.7, 50.6, 16.2; IR (neat): 2934, 1722,
129.5, 129.4, 126.8, 51.1, 21.2, 16.1; IR (neat): 3024, 2922, 1903, 1689,
1616,1514, 1435,1365,1205,1189, 969, 808, 712 cmꢂ1; HRMS (EI, m/
z) calcd for C12H14O: 174.1045 [Mþ], found: 174.1047.
1690, 1627, 1595, 1492, 1440, 1409, 1282, 1187, 970, 806, 760 cmꢂ1
;
HRMS (EI, m/z) calcd for C11H11ClO: 194.0498 [Mþ], found:
194.0497.
4.3.14. (E)-1-(4-Methylphenyl)pent-3-en-2-one (2gE). Light yellow
4.3.6. (E)-1-(4-Chlorophenyl)pent-3-en-2-one (2cE). Light yellow
oil (381.7 mg, 73% yield). 1H NMR (400 MHz, CDCl3):
d 7.13e7.00 (m,
oil (408.7 mg, 70% yield). 1H NMR (400 MHz, CDCl3):
d
7.29 (d,
4H), 6.95e6.87 (m, 1H), 6.14 (dd, J¼15.8, 1.6 Hz, 1H), 3.75 (s, 2H),
J¼8.4 Hz, 2H), 7.13 (d, J¼8.4 Hz, 2H), 6.98e6.89 (m, 1H), 6.16 (dd,
2.31 (s, 3H), 1.84 (dd, J¼6.8, 1.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
J¼16.0, 1.6 Hz, 1H), 3.79 (s, 2H), 1,89 (dd, J¼6.8, 1.2 Hz, 3H); 13C NMR
d
197.5, 143.6, 136.4, 131.4, 130.9, 129.4, 129.3, 47.1, 21.1, 16.4; IR
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J. Sun et al. / Tetrahedron xxx (2014) 1e6
5
(neat): 3022, 2955, 2854, 1691, 1670, 1629, 1514, 1375, 1292, 1185,
969, 842, 715 cmꢂ1; HRMS (EI, m/z) calcd for C12H14O: 174.1045
[Mþ], found: 174.1050.
124.2, 49.5,16.1; IR (neat): 3364, 3274, 2956, 2922,1903,1725,1592,
1486, 1449,1340,1282,1121,1010, 829, 792, 613 cmꢂ1; HRMS (EI, m/
z) calcd for C15H14O: 210.1045 [Mþ], found: 210.1039.
4.3.15. (Z)-1-(2-Methoxyphenyl)pent-3-en-2-one (2hZ). Light yel-
4.3.22. (E)-1-(Naphthalen-1-yl)pent-3-en-2-one (2kE). Light yel-
low oil (97.5 mg, 17% yield). 1H NMR (400 MHz, CDCl3):
d
7.27e7.21
low oil (503.6 mg, 80% yield). 1H NMR (400 MHz, CDCl3):
d 7.96 (d,
(m,1H), 7.13 (dd, J¼7.6,1.6 Hz,1H), 6.85e6.95 (m, 2H), 6.21e6.10 (m,
J¼8.0 Hz,1H), 7.89 (d, J¼7.2 Hz,1H), 7.82 (d, J¼8.0 Hz,1H), 7.59e7.43
(m, 3H), 7.39 (d, J¼6.8 Hz, 1H), 7.05e6.93 (m, 1H), 6.25 (dd, J¼15.6,
2.0 Hz, 1H), 4.23 (s, 2H), 1.80 (dd, J¼7.2, 0.8 Hz, 3H); 13C NMR
2H), 3.79 (s, 3H), 3.72 (s, 2H), 2.10 (d, J¼6.0 Hz, 3H); 13C NMR
(100 MHz, CDCl3):
d 199.3, 157.4, 143.3, 131.2, 128.4, 127.0, 123.7,
120.6, 110.5, 55.4, 45.8, 15.9; IR (neat): 3026, 2938, 2837, 1689, 1616,
1494, 1463, 1365, 1246, 1174, 970, 833, 702 cmꢂ1; HRMS (EI, m/z)
calcd for C12H14O2: 190.0994 [Mþ], found: 190.1000.
(100 MHz, CDCl3): d 197.3, 143.7, 134.1, 131.5, 132.6, 130.4, 128.9,
128.4, 128.0, 126.5, 126.0, 125.7, 124.3, 46.0, 18.3; IR (neat): 3044,
2939, 2911, 2848, 1938, 1687, 1627, 1597, 1440, 1398, 1242, 1189,
1164, 969, 869, 792, 737 cmꢂ1; HRMS (EI, m/z) calcd for C15H14O:
210.1045 [Mþ], found: 210.1039.
4.3.16. (E)-1-(2-Methoxyphenyl)pent-3-en-2-one (2hE). Light yel-
low oil (444.1 mg, 78% yield). 1H NMR (400 MHz, CDCl3):
d
7.25e7.18 (m, 1H), 7.11 (dd, J¼7.6, 1.6 Hz, 1H), 6.96e6.86 (m, 2H),
4.3.23. (Z)-1-(2-Methylnaphthalen-1-yl)pent-3-en-2-one (2lZ). Yel-
lowish solid (107.4 mg, 16% yield); mp: 62e64 ꢀC. 1H NMR (400 MHz,
6.84 (d, J¼8.4 Hz, 1H), 6.18e6.11 (m, 1H), 3.78 (s, 2H), 3.74 (s, 3H),
1.82 (dd, J¼10.8, 1.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d
197.7,
CDCl3):
d
7.86 (d, J¼8.4 Hz,1H), 7.79 (d, J¼8.4 Hz,1H), 7.69 (d, J¼8.4 Hz,
157.4, 142.9, 131.2, 131.1, 128.4, 123.7, 120.7, 110.6, 55.4, 42.1, 18.3; IR
(neat): 3006, 2940, 2837, 1691, 1630, 1495, 1464, 1375, 1267, 1029,
970, 754 cmꢂ1; HRMS (EI, m/z) calcd for C12H14O2: 190.0994 [Mþ],
found: 190.0990.
1H), 7.50e7.37(m, 2H), 7.33(d,J¼8.4 Hz,1H), 6.16e6.05 (m, 2H), 4.18 (s,
2H), 2.47 (s, 3H), 2.08 (dd, J¼3.2, 2.0 Hz, 3H); 13C NMR (100 MHz,
CDCl3): d199.0,144.5,134.7,132.8,132.5,129.1,128.6,128.6,127.4,126.5,
126.3, 124.8, 123.6, 44.8, 20.8, 16.0; IR (KBr): 3051, 2956, 2923, 2870,
2854, 1686, 1460, 1377, 1305, 1193, 1078, 959, 864, 809, 740 cmꢂ1
HRMS (EI, m/z) calcd for C16H16O: 224.1201 [Mþ], found: 224.1203.
;
4.3.17. (Z)-1-(3-Methoxyphenyl)pent-3-en-2-one (2iZ). Light yel-
low oil (85.7 mg, 15% yield). 1H NMR (400 MHz, CDCl3):
d 7.23 (d,
J¼8.0 Hz,1H), 6.80 (dd, J¼8.0, 8.0 Hz, 2H), 6.75 (s,1H), 6.27e6.17 (m,
4.3.24. (E)-1-(2-Methylnaphthalen-1-yl)pent-3-en-2-one
(2lE).-
2H), 3.80 (s, 3H), 3.70 (s, 2H), 2.11 (d, J¼7.2 Hz, 3H); 13C NMR
Yellowish solid (524.6 mg, 78% yield); mp: 60e62 ꢀC. 1H NMR
(100 MHz, CDCl3):
d
197.3, 159.9, 143.8, 136.1, 130.9, 129.7, 121.9,
(400 MHz, CDCl3):
d
7.78 (d, J¼8.8 Hz, 2H), 7.68 (d, J¼8.4 Hz, 1H),
115.1, 112.5, 55.3, 47.7, 18.4; IR (neat): 3383, 2923, 2836, 1740, 1692,
1630, 1489, 1376, 1260, 1191, 970, 875, 696 cmꢂ1; HRMS (EI, m/z)
calcd for C12H14O2: 190.0994 [Mþ], found: 190.1002.
7.47e7.34 (m, 2H), 7.31 (d, J¼8.4 Hz, 1H), 7.03e6.91 (m, 1H), 6.14
(dd, J¼15.2, 1.6 Hz, 1H), 4.21 (s, 2H), 2.42 (s, 3H), 1.79 (dd, J¼6.8,
1.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d 197.2, 143.6, 134.9, 133.0,
132.7, 130.3, 129.3, 128.8, 128.6, 127.6, 126.6, 124.9, 123.6, 41.7, 20.9,
18.5; IR (KBr): 3050, 2925, 2865, 1912, 1685, 1628, 1599, 1512, 1440,
1324, 1191, 1125, 969, 810, 741 cmꢂ1; HRMS (EI, m/z) calcd for
4.3.18. (E)-1-(3-Methoxyphenyl)pent-3-en-2-one (2iE). Light yellow
oil (450.1 mg, 79% yield). 1H NMR (400 MHz, CDCl3):
d
7.23 (dd, J¼7.8,
7.8 Hz, 1H), 6.98e6.87 (m, 1H), 6.82e6.74 (m, 3H), 6.16 (dd, J¼15.6,
C
16H16O: 224.1201 [Mþ], found: 224.1206.
1.6 Hz,1H), 3.79(s, 3H), 3.77(s, 2H),1.87(dd, J¼6.8,1.6 Hz, 3H); 13CNMR
(100 MHz, CDCl3): d 197.3, 159.9, 143.9, 136.1, 130.9, 129.7, 121.9, 115.1,
Acknowledgements
112.5, 55.2, 47.7, 18.4; IR (neat): 3003, 2939, 2917, 2836, 2027, 1691,
1628, 1600, 1584, 1490, 1260, 1150, 1048, 970, 876, 780, 756 cmꢂ1
;
We are grateful to the National Natural Science Foundation of
China (Nos. 21073025 and 21373041) and Natural Science Foun-
dation of Liaoning Province (No. 2013020113) for their financial
support. This work was partly supported by the Fundamental Re-
search Funds for the Central Universities (DUT13LK03).
HRMS (EI, m/z) calcd for C12H14O2: 190.0994 [Mþ], found: 190.0988.
4.3.19. (Z)-1-(4-Methoxyphenyl)pent-3-en-2-one (2jZ). Light yel-
low oil (127.2 mg, 22% yield). 1H NMR (400 MHz, CDCl3):
d 7.12 (d,
J¼8.4 Hz, 2H), 6.86 (d, J¼8.8 Hz, 2H), 6.25e6.14 (m, 2H), 3.79 (s, 3H),
3.66 (s, 2H), 2.10 (dd, J¼16.0, 10.4 Hz, 3H); 13C NMR (100 MHz,
Supplementary data
CDCl3):
d 199.2, 158.7, 144.3, 130.6, 126.8, 126.6, 114.2, 55.3, 50.5,
16.1; IR (neat): 3002, 2934, 2836, 1688, 1613, 1512, 1464, 1300, 1248,
1178, 1034, 971, 821, 729 cmꢂ1; HRMS (EI, m/z) calcd for C12H14O2:
190.0994 [Mþ], found: 190.0998.
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2014.07.002.
References and notes
4.3.20. (E)-1-(4-Methoxyphenyl)pent-3-en-2-one (2jE). Light yel-
low oil (402.9 mg, 71% yield). 1H NMR (400 MHz, CDCl3):
d 7.11 (d,
1. For books, see: (a) Beller, M. Catalytic Carbonylation Reactions; Springer: Berlin,
ꢀ
J¼8.8 Hz, 2H), 6.95e6.86 (m, 1H), 6.84 (d, J¼8.8 Hz, 2H), 6.14 (dd,
2006; (b) Kollar, L. Modern Carbonylation Methods; Wiley-VCH: Weinheim,
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J¼16.0, 1.6 Hz, 1H), 3.75 (s, 3H), 3.72 (s, 2H), 1.84 (dd, J¼6.8, 1.6 Hz,
3H); 13C NMR (100 MHz, CDCl3):
d 197.7, 158.6, 143.6, 131.0, 130.5,
126.6, 114.2, 55.2, 46.7, 18.3; IR (neat): 3035, 2956, 2912, 2837, 1886,
1691, 1669, 1628, 1512, 1463, 1441, 1300, 1248, 1178, 1034, 970, 821,
751 cmꢂ1; HRMS (EI, m/z) calcd for C12H14O2: 190.0994 [Mþ],
found: 190.0987.
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oil (88.9 mg, 14% yield). 1H NMR (400 MHz, CDCl3):
d 7.91 (d,
J¼8.0 Hz,1H), 7.84 (d, J¼7.2 Hz,1H), 7.76 (d, J¼8.0 Hz,1H), 7.53e7.37
(m, 3H), 7.35 (d, J¼6.8 Hz, 1H), 6.23e6.08 (m, 2H), 4.13 (s, 2H), 2.07
(dd, J¼6.8, 1.6 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d 198.8, 144.7,
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S.-K.; Ryu, H.-C.; Hong, Y.-T. J. Chem. Soc., Perkin Trans. 1 2001, 1, 736.
134.0, 132.5, 131.4, 128.8, 128.3, 128.0, 126.5, 126.4, 125.9, 125.7,
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6
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Please cite this article in press as: Sun, J.; et al., Tetrahedron (2014), http://dx.doi.org/10.1016/j.tet.2014.07.002