CuI-catalyzed synthesis of functionalized terminal allenes from 1-alkynes

Article abstract of DOI:10.1002/ejoc.201201696

Relative to our original protocol that uses CuI (0.5 equiv.), paraformaldehyde (2.5 equiv.), and dicyclohexylamine (1.8 equiv.), a facile and efficient protocol for the gram-scale synthesis of functionalized terminal allenes by using CuI (7.5-10 mol-%), p

Full text of DOI:10.1002/ejoc.201201696

Job/Unit: O21696
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Date: 26-03-13 17:00:29
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FULL PAPER
DOI: 10.1002/ejoc.201201696
CuI-Catalyzed Synthesis of Functionalized Terminal Allenes from 1-Alkynes
Hongwen Luo[a] and Shengming Ma*[a,b]
Keywords: Synthetic methods / Heterogeneous catalysis / Copper / Alkynes / Allenes
Relative to our original protocol that uses CuI (0.5 equiv.),
paraformaldehyde (2.5 equiv.), and dicyclohexylamine
(1.8 equiv.), a facile and efficient protocol for the gram-scale
synthesis of functionalized terminal allenes by using CuI
(7.5–10 mol-%), paraformaldehyde (1.6 equiv.), and diiso-
propylamine (1.4 equiv.) has been developed. This method
accommodates different functional groups such as hydroxy
or carbonyl, and it also performed well in the synthesis of
allenylamides and 2,3-butadien-1-ol.
synthesize terminal allenes, we started the initial study by
using 1-phenyl-2-propyn-1-ol (1a), paraformaldehyde, diiso-
propylamine, and CuI (10%) in dioxane at 110 °C. This ex-
periment afforded allenol 2a in 88% yield according to
NMR spectroscopic data (Table 1, Entry 1). To improve the
yield, the effect of the amine, which was an important pa-
rameter in the CuI-catalyzed synthesis of 1,3-disubstituted
allenes,[7] was investigated. Dicyclohexylamine also per-
formed well to give 2a in 84% yield according to NMR
spectroscopic data (Table 1, Entry 2).[6a] However, morph-
oline, which was used in the ZnI2-mediated synthesis of 1,3-
disubstituted allenes,[6b] failed to give any allene product
(Table 1, Entry 3).
Introduction
As a useful class of compounds, allenes not only act as
versatile intermediates in organic synthesis,[1,2] but also exist
in many natural products and pharmaceuticals.[3] Thus, ef-
ficient synthetic methods for allenes from readily available
materials are highly desirable.[2h,4] So far, several one-step
syntheses of terminal allenes from 1-alkynes with paraform-
aldehyde in the presence of amines and CuI salts have been
developed.[5,6a] Recently, this group developed several meth-
ods for constructing terminal or 1,3-disubstituted allenes
from 1-alkynes, aldehydes and amines.[6] However, each of
them needs substoichiometric metal salts and an excess of
paraformaldehyde, which is the obvious shortcoming for
any large-scale synthesis. Herein, we wish to report a facile
and efficient CuI-catalyzed gram-scale synthesis of func-
tionalized terminal allenes from 1-alkynes, paraformalde-
hyde, and diisopropylamine.
Table 1. Optimization of conditions for the reaction of 1-phenyl-2-
propyn-1-ol (1a) with paraformaldehyde, amine, and metal catalyst.
Results and Discussion
In our previous work to prepare 1,3-disubstituted allenes
with CuI as the catalyst, we carried out one example syn-
thesis of a terminal allene. The reaction of CuI (10 mol-%),
1-(4-chlorophenyl)-2-propyn-1-ol (1d), paraformaldehyde
(1.6 equiv.) and di(n-butyl)amine (1.4 equiv.) in dioxane at
130 °C afforded 1-(4-chlorophenyl)buta-2,3-dien-1-ol (2d)
in 67% yield.[7] To develop a general catalytic version to
Entry Amine
Catalyst
[mol-%]
Conc.
[M]
Yield of
2a/2aЈ[%][a]
1
2
iPr2NH
Cy2NH
CuI (10)
CuI (10)
0.67
0.67
0.67
0.67
0.67
0.4
0.5
1
0.67
88:9
84:11
–/92
3
4
5
6
morpholine CuI (10)
iPr2NH
iPr2NH
iPr2NH
iPr2NH
iPr2NH
iPr2NH
CuBr (10)
ZnI2 (10)
CuI (10)
CuI (10)
CuI (10)
CuI (7.5)
66:23
25:60
84:14
85:12
86:7
[a] Shanghai Key Laboratory of Green Chemistry and Chemical
Process, Department of Chemistry, East China Normal
University,
7
3663 North Zhongshan Lu, Shanghai 200062, P. R. China
Fax: +86-21-6260-9305
E-mail: masm@sioc.ac.cn
8
9[b]
88[c]/–
[b] State Key Laboratory of Organometallic Chemistry, Shanghai
Institute of Organic Chemistry, Chinese Academy of Sciences,
345 Lingling Lu, Shanghai 200032, P. R. China
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.201201696.
[a] The yield was determined by 1H NMR spectroscopic analysis
with 1,3,5-trimethylbenzene as the internal standard. [b] The reac-
tion was conducted with on a 10 mmol scale of 1a for 10 h. [c] Iso-
lated yield.
Eur. J. Org. Chem. 0000, 0–0
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H. Luo, S. Ma
FULL PAPER
By using diisopropylamine as the amine, a further study can be synthesized in 88% yield, an improvement of 21%.[7]
on different metal catalysts was investigated. It was noted For alkyl- or heterocyclic-substituted substrates, the reac-
that CuI was a better catalyst than CuBr and ZnI2 (Table 1, tion also proceeded smoothly to afford α-allenols in moder-
Entries 4 and 5). Subsequent study on reagent concentra- ate to good yields (Table 2, Entries 7–12). When tertiary
tion revealed that the amount of solvent has limited influ- propargylic alcohols were applied (R1, R2 ϶ H), a longer
ence in the yield (Table 1, Entries 6–8). When the reaction reaction time and a slightly higher catalyst loading were
was carried out on a 10 mmol scale, it proceeded smoothly needed to obtain satisfactory results (Table 2, Entries 13–
to afford 2a in 88% isolated yield with CuI (7.5 mol-%) 15). To our delight, this protocol is also suitable for the
without any intermediate product 2aЈ (Table 1, Entry 9). synthesis of allenes with ether or thioether functionality
Relative to the reports of Crabbé, which used a mixture of (Table 3).
1-alkyne, paraformaldehyde, diisopropylamine and CuBr in
a ratio 1.0:2.5:2.0:0.5,[5c] and our previous work,[6a] which
improved the yield of allene products by using paraformal-
Table 3. Synthesis of allenes with ether and thioether functionality.
dehyde (2.5 equiv.), dicyclohexylamine (1.8 equiv.) and CuI
(0.5 equiv.), and the work of Nakamura,[5d] which decreased
the amount of CuBr catalyst to 0.3 equiv., but required high
temperatures and microwave irradiation, this protocol has
the obvious advantage with respect of the amount of cata-
lyst and paraformaldehyde. It should be noted that all reac-
tions in this study were carried out without the protection
of an inert atmosphere. Thus, we defined the reaction of 1-
alkynes (10 mmol) with paraformaldehyde (1.6 equiv.), di-
isopropylamine (1.4 equiv.), and CuI (7.5 mol-%) in diox-
ane at 110 °C as the standard for the study on the scope of
this procedure.
Entry
R
Time [h] Isolated yield of 2 [%]
1
2
3
4
5
4-O2NC6H4O (1p)
BnO (1q)
TBDMSO (1r)
THPO (1s)
BnS (1t)
11
76 (2p)
75 (2q)
60 (2r)
66 (2s)
79 (2t)
12.5
12.5
12.5
16
With the standard conditions in hand, the substrate
scope and generality of the reaction was investigated and
the results summarized in Table 2. The reaction of second-
ary alcohols 1b–1f bearing electron-donating or electron-
withdrawing substituents, such as o/p-OMe, p-Cl, or m-NO2
on the phenyl group afforded the corresponding allenols
2b–2f in good yields (Table 2, Entries 2–6). It should be
noted that under this set of reaction conditions, allenol 2d
Moreover, amide, carbonyl, or ω-hydroxy functionality
in the substrates is also tolerated on a 10 mmol-scale reac-
tion, affording the products in moderate yields (Scheme 1).
The example in Scheme 1 with simple 1-alkyne 1w as the
substrate demonstrates this non-functionalized alkyne is
also compatible with this method.
Table 2. The CuI-catalyzed reaction of substituted propargylic
alcohols, paraformaldehyde, and i-Pr2NH in dioxane.
Entry R1/R2
CuI
Time [h]
Isolated
yield
[mol-%]
7.5
4-MeOC6H4/H (1b) 7.5
2-MeOC6H4/H (1c) 7.5
4-ClC6H4/H (1d) 7.5
of 2 [%]
1
2
3
4
5
6
7
8
Ph/H (1a)
10
10
10
10
10
10.5
10
10
12
12
14
17
23
17
21
88 (2a)
79 (2b)
87 (2c)
88 (2d)
84 (2e)
81 (2f)
86 (2g)
76 (2h)
77 (2i)
59 (2j)
79 (2k)
82 (2l)
84 (2m)
74 (2n)
80 (2o)
2,4-Cl2C6H3/H (1e) 7.5
3-O2NC6H4/H (1f) 7.5
2-thienyl/H (1g)
2-furyl/H (1h)
nC5H11/H (1i)
nC7H15/H (1j)
Bn/H (1k)
cCy/H (1l)
Ph/Me (1m)
7.5
7.5
7.5
7.5
7.5
10
10
10
10
Scheme 1. Synthesis of allenes from functionalized or non-func-
tionalized 1-alkynes.
9
10
11
12
13
14
15
In 2011, Hashmi et al. synthesized allenylamides 4 by the
method of Crabbé[5a,8] with very low yields.[9] To prove the
potential of this protocol, a series of experiments were car-
ried out to synthesize this type of product. The substrate
nC6H13/Me (1n)
–(CH2)5– (1o)
2
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CuI-Catalyzed Synthesis of Functionalized Terminal Allenes
scope and generality of the reaction have been investigated
and the results are summarized in Table 4. In all cases this
method afforded allenylamides 4 in much higher yield than
previously reported. It should be noted that the thiophene-
base substrate also gave a good yield of 80%, which means
any interaction between the sulfur atom and the copper cat-
alyst does not seriously inhibit the reaction (Table 4, En-
try 6).
Table 4. The synthesis of allenylamides from propargylic amide, pa-
raformaldehyde, and iPr2NH in dioxane.
Scheme 3. Gram-scale synthesis of buta-2,3-dien-1-ol.
Conclusions
In conclusion, we have developed an efficient catalytic
synthesis of functionalized terminal allenes from readily
available terminal alkynes, paraformaldehyde and diiso-
propylamine. The high compatibility of functional groups
indicates the high potential of this protocol. Based on this
protocol, we developed two practical procedures to obtain
useful reagent 2,3-butadien-1-ol on a 12 g or 7 g scale.
Owing to the easy availability of all the reagents, high po-
tential of the functionalized allenes, and simple operation
as well as its catalytic nature, this method will be of interest
to organic and medicinal chemists although it is still some-
what lower-yielding relative to the reaction using CuI
(0.5 equiv.) and Cy2NH (1.8 equiv.).[6a] Further studies in
this area are being actively pursued in our laboratory.
Entry
R
Isolated yield Reported
yield
of 4 [%]
of 4 [%][a]
1
2
3
Ph (3a)
(E)-PhCH=CH (3b)
2-furyl (3c)
2,5-dimethylfuran-3-yl (3d) 84 (4d)
5-nitrofuran-2-yl (3e)
2-thienyl (3f)
adamantyl (3g)
EtO2C (3h)
EtO2CCH2 (3i)
EtO2CCH2CH2 (3j)
78 (4a)
82 (4b)
84 (4c)
34 (4a)
28 (4b)
55 (4c)
48 (4d)
24 (4e)
9 (4f)
4[b]
5[c]
6
53 (4e)
80 (4f)
64 (4g)
48 (4h)
28 (4i)
64 (4j)
7
8
9
10
15 (4g)
4 (4h)
8 (4i)
8 (4j)
[a] Conditions in ref.[9a]: Propargylic amide (1 equiv.) with para-
formaldehyde (2 equiv.), diisopropylamine (2 equiv.), and CuBr
(0.3 equiv.) in dioxane at 100 °C. [b] 1-alkyne (7 mmol) was used.
[c] Reaction time of 24 h.
Experimental Section
General Information: All reactions were carried out in oven-dried
three-neck round-bottom flasks. Paraformaldehyde (Ն 94.0%) and
CuI (Ն 99.5%) were purchased from Sinopharm Chemical Reagent
Co., Ltd. and used without further treatment. Dioxane was distilled
from sodium wire with diphenyl ketone as the indicator. THF was
dried with sodium wire. Diisopropylamine was dried with anhy-
drous barium oxide and distilled. All the temperatures stated refer
to the oil baths used.
Buta-2,3-dien-1-ol is a very simple but useful reagent in
organic synthesis.[3d,10] Traditional methods to synthesize
this compound often require a multistep manipulation from
but-2-yn-1,4-diol, and LiAlH4 as the reducing reagent in
the last step (Scheme 2).[3d,10a–10c]
Typical Procedure: Cu(I)-Catalyzed Gram-Scale Synthesis of 1-
Phenyl-2,3-butadien-1-ol (2a): To a 50 mL three-neck round-bottom
flask equipped with a magnetic stirring bar were added CuI
(143.2 mg, 0.75 mmol), paraformaldehyde (481.2 mg, 16.02 mmol),
and dioxane (10 mL). The resulting mixture was stirred at room
temperature before subsequent addition of iPr2NH (1.98 mL, d =
0.716 gmL–1, 1.4177 g, 14.01 mmol), 1a (1.3207 g, 10.00 mmol),
and dioxane (5 mL). The mixture was stirred at 110 °C without
protection with an inert atmosphere. After 10 h, the reaction mix-
ture was cooled to room temperature and filtered through a short
column of silica gel (Et2O). The solvent was evaporated, and the
residue was diluted with Et2O. After filtration again to remove the
precipitate, evaporation of the solvent and chromatography on sil-
ica gel (petroleum ether/ethyl acetate, 5:1 to 2:1) afforded 2a[11a]
(1.2915 g, 88%) as a liquid. 1H NMR (300 MHz, CDCl3): δ = 7.42–
7.21 (m, 5 H, ArH), 5.41 (q, J = 6.6 Hz, 1 H, C=CH), 5.26–5.19
(m, 1 H, OCH), 4.96–4.83 (m, 2 H, C=CH2), 2.50 (br. s, 1 H,
OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 207.0, 142.7, 128.4,
Scheme 2. Typical method for the synthesis of buta-2,3-dien-1-ol.
After extensive screening, tetrahydrofuran (THF) was
used instead of dioxane for the purpose of easy separation,
and we established two procedures to afford buta-2,3-dien-
1-ol (Scheme 3): (1) with heating to reflux, propargyl
alcohol (0.4 mol) reacts smoothly to afford 40–45% yield
of the product with CuI (0.5 equiv.). Here a catalytic
amount of CuI is not effective; and (2) interestingly, under
high-pressure autoclave conditions, CuI (10 mol-%) is suf-
ficient to get a better result of 50–53% yield (see Scheme 3). 127.7, 126.0, 95.1, 78.0, 71.9 ppm. IR (neat): ν = 3334, 1955, 1493,
˜
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H. Luo, S. Ma
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1452, 1022 cm–1. MS (70 eV, EI): m/z (%) = 146 (4.13) [M+], 107 81%) after purification (eluent for chromatography: petroleum
1
(100).
ether/ethyl acetate, 5:1) as a liquid. H NMR (300 MHz, CDCl3):
δ = 8.24 (s, 1 H, ArH), 8.10 (d, J = 7.8 Hz, 1 H, ArH), 7.72 (d, J
= 7.8 Hz, 1 H, ArH), 7.50 (t, J = 7.6 Hz, 1 H, ArH), 5.46–5.32 (m,
2 H, C=CH and OCH), 5.00–4.86 (m, 2 H, C=CH2), 2.84–2.55 (m,
1 H, OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 207.4, 148.2,
1-(4-Methoxyphenyl)-2,3-butadien-1-ol (2b): The reaction of CuI
(142.6 mg, 0.75 mmol), paraformaldehyde (480.2 mg, 15.99 mmol),
1b (1.6246 g, 10.02 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2b[11a] (1.3876 g,
79%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 7.36–7.27 (m, 2 H, ArH), 6.94–6.82 (m, 2 H, ArH),
5.43 (q, J = 6.6 Hz, 1 H, C=CH), 5.25–5.16 (m, 1 H, OCH), 4.97–
144.8, 132.2, 129.3, 122.5, 121.0, 94.4, 78.7, 71.0 ppm. IR (neat): ν
˜
= 3405, 1955, 1526, 1347 cm–1. MS (70 eV, EI): m/z (%) = 191
(0.58) [M+], 152 (100) [M+ – C3H3].
1-(Thiophen-2-yl)-2,3-butadien-1-ol (2g): The reaction of CuI
4.85 (m, 2 H, C=CH2), 3.80 (s, 3 H, OCH3), 2.43 (br. s, 1 H, (143.5 mg, 0.75 mmol), paraformaldehyde (480.5 mg, 16.00 mmol),
OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 207.0, 159.1, 135.0, 1g (1.3824 g, 10.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
127.4, 113.7, 95.2, 78.0, 71.4, 55.2 ppm. IR (neat): ν = 3397, 1955, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2g[11c] (1.3053 g,
˜
1611, 1585, 1511, 1246, 1173, 1032 cm–1. MS (70 eV, EI): m/z (%)
86%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 7.25 (d, J = 4.8 Hz, 1 H of thienyl group), 7.04–6.98
(m, 1 H of thienyl group), 6.98–6.90 (m, 1 H of thienyl group),
5.56–5.41 (m, 2 H, C=CH and OCH), 5.01–4.88 (m, 2 H, C=CH2),
2.60 (br. s, 1 H, OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ =
= 176 (9.32) [M+], 137 (100).
1-(2-Methoxyphenyl)-2,3-butadien-1-ol (2c): The reaction of CuI
(142.6 mg, 0.75 mmol), paraformaldehyde (481.6 mg, 16.04 mmol),
1c (1.6128 g, 9.94 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2c[10i] (1.5255 g,
87%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 15:1 to 10:1 to 5:1) as a liquid. 1H NMR
(300 MHz, CDCl3): δ = 7.33 (d, J = 7.5 Hz, 1 H, ArH), 7.26 (t, J
= 7.8 Hz, 1 H, ArH), 6.95 (t, J = 7.5 Hz, 1 H, ArH), 6.89 (d, J =
8.4 Hz, 1 H, ArH), 5.54 (q, J = 6.3 Hz, 1 H, C=CH), 5.47–5.38
207.1, 146.8, 126.6, 125.1, 124.2, 94.7, 78.6, 68.0 ppm. IR (neat): ν
˜
= 3378, 1954, 1227, 1077 cm–1. MS (70 eV, EI): m/z (%) = 152
(8.97) [M+], 113 (100).
1-(Furan-2-yl)-2,3-butadien-1-ol (2h): The reaction of CuI
(142.5 mg, 0.75 mmol), paraformaldehyde (481.1 mg, 16.02 mmol),
(m, 1 H, OCH), 4.92–4.78 (m, 2 H, C=CH2), 3.85 (s, 3 H, OCH3), 1h (1.2161 g, 9.96 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
3.01–2.93 (m, 1 H, OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2h[11c] (1.0307 g,
76%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 7.42–7.35 (m, 1 H of furan group), 6.36–6.31 (m, 1 H
of furan group), 6.31–6.25 (m, 1 H of furan group), 5.51 (q, J =
6.6 Hz, 1 H, C=CH), 5.30–5.20 (m, 1 H, OCH), 5.01–4.89 (m, 2
H, C=CH2), 2.54–2.44 (m, 1 H, OH) ppm. 13C NMR (75.4 MHz,
CDCl3): δ = 207.6, 154.9, 142.3, 110.2, 106.5, 92.1, 78.5, 65.6 ppm.
= 207.1, 156.6, 130.8, 128.7, 127.1, 120.8, 110.6, 94.1, 77.7, 68.8,
55.3 ppm. IR (neat): ν = 3405, 1955, 1601, 1588, 1490, 1463, 1439,
˜
1240, 1048, 1026 cm–1. MS (70 eV, EI): m/z (%) = 176 (3.57) [M+],
137 (100).
1-(4-Chlorophenyl)-2,3-butadien-1-ol (2d): The reaction of CuI
(142.7 mg, 0.75 mmol), paraformaldehyde (481.4 mg, 16.03 mmol),
1d (1.6655 g, 10.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2d[7] (1.5817 g,
88%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR (300 MHz,
IR (neat): ν = 3558, 1957, 1503, 1146, 1008 cm–1. MS (70 eV, EI):
˜
m/z (%) = 136 (9.08) [M+], 97 (100).
1,2-Nonadien-4-ol (2i): The reaction of CuI (143.0 mg, 0.75 mmol),
CDCl3): δ = 7.29 (s, 4 H, ArH), 5.37 (q, J = 6.3 Hz, 1 H, C=CH), paraformaldehyde (480.6 mg, 16.00 mmol), 1i (1.2625 g,
5.24–5.16 (m, 1 H, OCH), 4.90 (d, J = 6.3 Hz, 2 H, C=CH2), 2.65– 10.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1, 1.432 g,
2.43 (m, 1 H, OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 207.1,
14.15 mmol) in dioxane (15 mL) afforded 2i[11a] (1.0788 g, 77%) af-
141.2, 133.3, 128.5, 127.4, 94.8, 78.3, 71.2 ppm. IR (neat): ν = 3357,
ter purification (eluent for chromatography: petroleum ether/ethyl
acetate, 10:1 to 5:1) as a liquid. H NMR (300 MHz, CDCl3): δ =
5.19 (q, J = 6.6 Hz, 1 H, C=CH), 4.86–4.74 (m, 2 H, C=CH2),
4.18–4.07 (m, 1 H, OCH), 2.20 (br. s, 1 H, OH), 1.63–1.17 (m, 8
H, 4 ϫ CH2), 0.86 (t, J = 6.6 Hz, 3 H, CH3) ppm. 13C NMR
(75.4 MHz, CDCl3): δ = 206.9, 94.7, 77.1, 69.7, 37.3, 31.6, 25.0,
˜
2888, 1955, 1597, 1491, 1406, 1091, 1013 cm–1. MS (70 eV, EI): m/z
1
(%) = 182 (0.86) [M+ (37Cl)], 180 (2.61) [M+ (35Cl)], 141 (100).
1-(2,4-Dichlorophenyl)-2,3-butadien-1-ol (2e): The reaction of CuI
(142.9 mg, 0.75 mmol), paraformaldehyde (480.4 mg, 16.00 mmol),
1e (2.0153 g, 10.02 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2e (1.8157 g,
84%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1 to 5:1) as a solid, m.p. 56–58 °C (petroleum
ether/ethyl acetate). 1H NMR (300 MHz, CDCl3): δ = 7.50 (d, J =
8.1 Hz, 1 H, ArH), 7.34 (d, J = 2.1 Hz, 1 H, ArH), 7.25 (dd, J =
8.1, 2.1 Hz, 1 H, ArH), 5.62–5.54 (m, 1 H, OCH), 5.40 (q, J =
6.6 Hz, 1 H, C=CH), 4.91 (dd, J = 6.3, 2.3 Hz, 2 H, C=CH2), 2.59–
2.49 (m, 1 H, OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 207.2,
136.4, 130.6, 130.3, 128.5, 127.8, 126.5, 93.8, 78.1, 70.4 ppm. IR
22.5, 13.9 ppm. IR (neat): ν = 3317, 2957, 2930, 2859, 1956, 1464,
˜
1020 cm–1. MS (70 eV, EI): m/z (%) = 111 (4.32) [M+ – C2H5], 83
(100).
1,2-Undecadien-4-ol (2j): The reaction of CuI (142.5 mg,
0.75 mmol), paraformaldehyde (480.8 mg, 16.01 mmol), 1j
(1.5484 g, 10.04 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2j[11d] (0.9972 g,
59%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 5.23 (q, J = 6.5 Hz, 1 H, C=CH), 4.90–4.78 (m, 2 H,
C=CH2), 4.22–4.10 (m, 1 H, OCH), 1.73–1.18 (m, 13 H, OH and 6
(neat): ν = 3333, 1957, 1632, 1590, 1543, 1511, 1468, 1247,
˜
1037 cm–1. MS (70 eV, EI): m/z (%) = 218 (0.17) [M+ 37,37Cl)], 216
(
(1.00) [M+ 37,35Cl)], 214 (1.58) [M+ 35,35Cl)], 175 (100). HRMS: ϫ CH2), 0.87 (t, J = 5.9 Hz, 3 H, CH3) ppm. 13C NMR (75.4 MHz,
( (
calcd. for C10H835,35Cl2O [M+] 213.9952; found 213.9954.
CDCl3): δ = 207.0, 94.9, 77.3, 69.7, 37.5, 31.8, 29.4, 29.2, 25.4,
22.6, 14.0 ppm. IR (neat): ν = 3333, 2926, 2856, 1957, 1466 cm–1.
˜
1-(3-Nitrophenyl)-2,3-butadien-1-ol (2f): The reaction of CuI
(142.5 mg, 0.75 mmol), paraformaldehyde (480.5 mg, 16.00 mmol),
1f (1.7732 g, 10.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2f[11b] (1.5460 g,
MS (70 eV, EI): m/z (%) = 129 (10.57) [M+ – C3H3], 69 (100).
1-Phenyl-3,4-pentadien-2-ol (2k): The reaction of CuI (142.6 mg,
0.75 mmol), paraformaldehyde (481.2 mg, 16.02 mmol), 1k
4
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Job/Unit: O21696
/KAP1
Date: 26-03-13 17:00:29
Pages: 9
CuI-Catalyzed Synthesis of Functionalized Terminal Allenes
(1.4583 g, 9.98 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1448, 1147, 1056 cm–1. MS (70 eV, EI): m/z (%) = 138 (0.85) [M+],
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2k[11e] (1.2690 g, 120 (3.40) [M+ – H2O], 99 (100).
79%) after purification (eluent for chromatography: petroleum
1-(Buta-2,3-dien-1-yloxy)-4-nitrobenzene (2p): The reaction of CuI
ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 7.36–7.16 (m, 5 H, ArH), 5.28 (q, J = 6.3 Hz, 1 H,
C=CH), 4.90–4.77 (m, 2 H, C=CH2), 4.46–4.33 (m, 1 H, OCH),
2.95–2.78 (m, 2 H, CH2), 1.89 (br. s, 1 H, OH) ppm. 13C NMR
(75.4 MHz, CDCl3): δ = 206.9, 137.6, 129.5, 128.3, 126.4, 94.0,
(190.3 mg, 1.00 mmol), paraformaldehyde (480.3 mg, 15.99 mmol),
1p (1.7789 g, 10.04 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2p (1.4635 g,
76%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 20:1 to 10:1) as a solid, m.p. 60–62 °C (petro-
77.7, 70.1, 43.8 ppm. IR (neat): ν = 3377, 1955, 1603, 1496, 1453,
˜
1
leum ether/ethyl acetate): H NMR (300 MHz, CDCl3): δ = 8.22–
1049, 1028 cm–1. MS (70 eV, EI): m/z (%) = 160 (0.62) [M+], 159
8.13 (m, 2 H, ArH), 7.00–6.75 (m, 2 H, ArH), 5.37 (quint, J =
6.8 Hz, 1 H, C=CH), 4.90 (dt, J = 6.6, 2.1 Hz, 2 H, C=CH2), 4.65
(dt, J = 6.9, 2.4 Hz, 2 H, OCH2) ppm. 13C NMR (75.4 MHz,
CDCl3): δ = 209.6, 163.2, 141.5, 125.8, 114.8, 86.1, 77.1, 66.4 ppm.
(1.80) [M+ – H], 92 (100).
1-Cyclohexyl-2,3-butadien-1-ol (2l): The reaction of CuI (190.6 mg,
1.00 mmol), paraformaldehyde (480.7 mg, 16.01 mmol), 1l
(1.3827 g, 10.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2l[11d] (1.2546 g,
82%) after purification (eluent for chromatography: petroleum
IR (neat): ν = 2930, 1958, 1606, 1592, 1509, 1342, 1256, 1112 cm–1.
˜
MS (70 eV, EI): m/z (%) = 191 (1.26) [M+], 53 (100). HRMS: calcd.
for C10H9NO3 [M+] 191.0582; found 191.0583.
1
ether/ethyl acetate, 5:1) as a liquid. H NMR (300 MHz, CDCl3):
Benzyl 2,3-Butadienyl Ether (2q): The reaction of CuI (190.5 mg,
1.00 mmol), paraformaldehyde (480.5 mg, 16.00 mmol), 1q
(1.4666 g, 10.03 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2q[6a] (1.2001 g,
75%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 40:1) as a liquid. 1H NMR (300 MHz, CDCl3):
δ = 7.38–7.22 (m, 5 H, ArH), 5.28 (quint, J = 6.6 Hz, 1 H, C=CH),
4.83–4.75 (m, 2 H, C=CH2), 4.53 (s, 2 H, ArCH2), 4.06 (d, J =
6.9 Hz, 2 H, OCH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ =
209.3, 138.1, 128.3, 127.8, 127.6, 87.7, 75.6, 71.8, 67.8 ppm. IR
δ = 5.21 (q, J = 6.6 Hz, 1 H, C=CH), 4.82 (dd, J = 6.8, 2.2 Hz, 2
H, C=CH2), 3.97–3.86 (m, 1 H, OCH), 1.90–1.58 (m, 6 H, Cy),
1.49–1.34 (m, 1 H, OH), 1.31–0.91 (m, 5 H, Cy) ppm. 13C NMR
(75.4 MHz, CDCl3): δ = 207.2, 93.2, 77.1, 74.0, 44.1, 28.6, 28.3,
26.4, 26.03. 25.97 ppm. IR (neat): ν = 3354, 2923, 2852, 1955, 1449,
˜
1083, 1014 cm–1. MS (70 eV, EI): m/z (%) = 152 (0.51) [M+], 134
(1.22) [M+ – H2O], 69 (100).
2-Phenyl-3,4-pentadien-2-ol (2m): The reaction of CuI (191.2 mg,
1.00 mmol), paraformaldehyde (481.4 mg, 16.03 mmol), 1m
(1.4657 g, 10.03 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2m[11f] (1.3540 g,
84%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 10:1) as a liquid. 1H NMR (300 MHz, CDCl3):
δ = 7.49 (d, J = 7.8 Hz, 2 H, ArH), 7.33 (t, J = 7.2 Hz, 2 H, ArH),
7.23 (t, J = 6.9 Hz, 1 H, ArH), 5.54 (t, J = 6.4 Hz, 1 H, C=CH),
5.00–4.85 (m, 2 H, C=CH2), 2.30 (s, 1 H, OH), 1.64 (s, 3 H,
CH3) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 205.8, 147.1, 128.1,
(neat): ν = 3094, 3031, 2858, 1955, 1496, 1453, 1360, 1074, 1051,
˜
1029, 1003 cm–1. MS (70 eV, EI): m/z (%) = 130 (27.21) [M+
–
CH2O], 91 (100).
(Buta-2,3-dien-1-yloxy)(tert-butyl)dimethylsilane (2r): The reaction
of CuI (191.3 mg, 1.00 mmol), paraformaldehyde (481.6 mg,
16.04 mmol), 1r (1.7113 g, 10.05 mmol), and iPr2NH (2.0 mL, d
= 0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
2r[11h] (1.1115 g, 60%) after purification (eluent for chromatog-
raphy: 30–60 °C petroleum ether) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 5.23 (quint, J = 6.5 Hz, 1 H, C=CH), 4.81–4.70 (m, 2
H, C=CH2), 4.24–4.14 (m, 2 H, OCH2), 0.90 (s, 9 H, tBu), 0.08 (s,
6 H, 2 ϫ SiCH3) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 208.1,
126.9, 124.9, 100.1, 79.0, 72.9, 30.3 ppm. IR (neat): ν = 3363, 3028,
˜
1956, 1492, 1446, 1217, 1178, 1102, 1067, 1028 cm–1. MS (70 eV,
EI): m/z (%) = 160 (1.79) [M+], 121 (100).
90.9, 76.0, 61.4, 25.9, 18.4, –5.1 ppm. IR (neat): ν = 2858, 1958,
4-Methyl-1,2-decadien-4-ol (2n): The reaction of CuI (190.6 mg,
1.00 mmol), paraformaldehyde (480.7 mg, 16.01 mmol), 1n
(1.5403 g, 9.98 mmol), and iPr2NH (1.98 mL, d = 0.716 gmL–1,
1.4177 g, 14.01 mmol) in dioxane (15 mL) afforded 2n[11g]
(1.2535 g, 74%) after purification (eluent for chromatography: pe-
˜
1471, 1255, 1085 cm–1. MS (70 eV, EI): m/z (%) = 127 (51.00) [M+ –
tBu], 75 (100). Please note that the dioxane should be evaporated
Ͻ 40 °C/4.8 kPa to ensure the yield.
2-(Buta-2,3-dien-1-yloxy)tetrahydro-2H-pyran (2s): The reaction of
CuI (191.1 mg, 1.00 mmol), paraformaldehyde (481.0 mg,
16.02 mmol), 1s (1.4010 g, 9.99 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
2s[11i] (1.0234 g, 66%) after purification (eluent for chromatog-
1
troleum ether/ethyl acetate, 5:1) as a liquid. H NMR (300 MHz,
CDCl3): δ = 5.24 (t, J = 6.6 Hz, 1 H, C=CH), 4.84 (d, J = 6.6 Hz,
2 H, C=CH2), 1.87 (s, 1 H, OH), 1.59–1.45 (m, 2 H, CH2), 1.39–
1.18 (m, 11 H, CH3 and 4 ϫ CH2), 0.85 (t, J = 6.4 Hz, 3 H,
CH3) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 205.5, 99.3, 78.2,
1
raphy: petroleum ether/ethyl acetate = 20:1) as a liquid. H NMR
71.3, 42.8, 31.8, 29.6, 27.7, 24.0, 22.5, 14.0 ppm. IR (neat): ν =
˜
(300 MHz, CDCl3): δ = 5.26 (quint, J = 6.5 Hz, 1 H, C=CH), 4.82–
4.72 (m, 2 H, C=CH2), 4.72–4.64 (m, 1 H, OCHO), 4.28–4.15 (m,
1 H of OCH2), 4.09–3.98 (m, 1 H of OCH2), 3.93–3.80 (m, 1 H of
OCH2), 3.56–3.45 (m, 1 H of OCH2), 1.92–1.43 (m, 6 H, 3 ϫ
CH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 209.3, 97.6, 87.8,
3368, 2958, 2932, 2860, 1957, 1464, 1375, 1128, 1061 cm–1. MS
(70 eV, EI): m/z (%) = 168 (0.14) [M+], 153 (2.39) [M+ – CH3], 83
(100).
1-(Propa-1,2-dienyl)cyclohexanol (2o): The reaction of CuI
(190.1 mg, 1.00 mmol), paraformaldehyde (480.0 mg, 15.98 mmol),
1o (97% purity, 1.2838 g, 10.03 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
75.6, 64.8, 62.2, 30.5, 25.4, 19.4 ppm. IR (neat): ν = 2943, 1957,
˜
1056, 1023 cm–1. MS (70 eV, EI): m/z (%) = 115 (2.80) [M+ – C3H3],
85 (100).
2o[11a] (1.1056 g, 80%) after purification (eluent for chromatog- 4-Benzylthio-1,2-butadiene (2t): The reaction of CuI (190.9 mg,
raphy: petroleum ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H
NMR (300 MHz, CDCl3): δ = 5.28 (t, J = 6.6 Hz, 1 H, C=CH),
4.86 (d, J = 6.6 Hz, 2 H, C=CH2), 1.74–1.18 (m, 11 H, OH and 5
ϫ CH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 206.2, 99.4, 78.1,
1.00 mmol), paraformaldehyde (481.3 mg, 16.03 mmol), 1t
(1.6255 g, 1.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2t[11j] (1.4032 g,
79%) after purification (eluent for chromatography: petroleum
1
70.4, 38.3, 25.5, 22.5 ppm. IR (neat): ν = 3354, 2931, 2854, 1955,
ether) as a liquid. H NMR (300 MHz, CDCl3): δ = 7.34–7.17 (m,
˜
Eur. J. Org. Chem. 0000, 0–0
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
5

Job/Unit: O21696
/KAP1
Date: 26-03-13 17:00:29
Pages: 9
H. Luo, S. Ma
FULL PAPER
5 H, ArH), 5.16 (quint, J = 7.1 Hz, 1 H, C=CH), 4.85–4.76 (dd, J
= 6.2, 2.0 Hz, 2 H, C=CH2), 3.72 (s, 2 H, ArCH2), 3.07–2.96 (m,
2 H, SCH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 209.6, 138.2,
N-(Buta-2,3-dien-1-yl)benzamide (4a): The reaction of CuI
(190.7 mg, 1.00 mmol), paraformaldehyde (480.8 mg, 16.01 mmol),
3a (1.5918 g, 10.00 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 4a[9a] (1.3601 g,
78%) after purification (eluent for chromatography: petroleum
ether/ethyl acetate, 5:1 to 2:1) as a solid, m.p. 51–53 °C (petroleum
ether/ethyl acetate). 1H NMR (300 MHz, CDCl3): δ = 7.77 (d, J =
7.8 Hz, 2 H, ArH), 7.53–7.33 (m, 3 H, ArH), 6.57 (br. s, 1 H, NH),
5.31 (quint, J = 6.2 Hz, 1 H, C=CH), 4.92–4.80 (m, 2 H, C=CH2),
4.09–3.96 (m, 2 H, NCH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ
= 207.9, 167.3, 134.4, 131.4, 128.4, 126.9, 88.0, 77.7, 37.8 ppm. IR
128.9, 128.4, 126.9, 87.8, 76.1, 35.0, 29.8 ppm. IR (neat): ν = 1949,
˜
1494, 1453, 1416, 1322, 1224 cm–1. MS (70 eV, EI): m/z (%) = 176
(3.72) [M+], 91 (100).
4-Methyl-N-(nona-1,2-dien-4-yl)benzenesulfonamide (2u): The reac-
tion of CuI (191.0 mg, 1.00 mmol), paraformaldehyde (481.6 mg,
16.04 mmol), 1u (2.7886 g, 9.98 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2u
(2.0181 g, 69%) after purification (eluent for chromatography: pe-
troleum ether/ethyl acetate, 10:1 to 5:1) as a liquid. 1H NMR
(300 MHz, CDCl3): δ = 7.75 (d, J = 7.8 Hz, 2 H, ArH), 7.28 (d, J
= 7.8 Hz, 2 H, ArH), 4.95 (q, J = 6.3 Hz, 1 H, C=CH), 4.75–4.54
(m, 3 H, NH and C=CH2), 3.87–3.72 (m, 1 H, NCH), 2.42 (s, 3
(neat): ν = 3316, 1955, 1641, 1537, 1489, 1293 cm–1. MS (70 eV,
˜
EI): m/z (%) = 173 (12.93) [M+], 105 (100).
(E)-N-(Buta-2,3-dien-1-yl)-3-phenylacrylamide (4b): The reaction of
CuI (190.6 mg, 1.00 mmol), paraformaldehyde (480.0 mg,
H, ArCH3), 1.60–1.39 (m, 2 H, CH2), 1.39–1.10 (m, 6 H, 3 ϫ CH2), 15.98 mmol), 3b (1.8525 g, 10.00 mmol), and iPr2NH (2.0 mL, d =
0.85 (t, J = 6.3 Hz, 3 H, CH3) ppm. 13C NMR (75.4 MHz, CDCl3):
δ = 206.8, 143.2, 138.1, 129.4, 127.2, 92.4, 78.3, 52.1, 36.1, 31.3,
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
4b[9a] (1.6313 g, 82%) after purification (eluent for chromatog-
raphy: petroleum ether/ethyl acetate, 5:1 to 2:1) as a solid, m.p. 72–
74 °C (petroleum ether/ethyl acetate). 1H NMR (300 MHz,
CDCl3): δ = 7.64 (d, J = 15.9 Hz, 1 H, C=CH), 7.52–7.43 (m, 2 H,
ArH), 7.37–7.27 (m, 3 H, ArH), 6.47 (d, J = 15.6 Hz, 1 H, C=CH),
6.30 (br. s, 1 H, NH), 5.27 (quint, J = 6.3 Hz, 1 H, C=CH), 4.90–
4.79 (m, 2 H, C=C=CH2), 4.04–3.94 (m, 2 H, CH2) ppm. 13C NMR
(75.4 MHz, CDCl3): δ = 208.0, 165.8, 141.0, 134.7, 129.6, 128.7,
24.9, 22.4, 21.5, 13.9 ppm. IR (neat): ν = 3271, 2930, 1957, 1598,
˜
1426, 1324, 1158 cm–1. MS (70 eV, EI): m/z (%) = 293 (2.26) [M+],
91 (100). HRMS: calcd. for C16H23NO2S [M+] 293.1450; found
293.1451.
Hepta-5,6-dien-1-ol (2v): The reaction of CuI (190.9 mg,
1.00 mmol), paraformaldehyde (480.7 mg, 16.01 mmol), 1v
(0.9850 g, 10.04 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2v[11k] (0.5541 g,
49%) after purification (eluent for chromatography: petroleum
127.7, 120.5, 87.8, 77.5, 37.8 ppm. IR (neat): ν = 3243, 3063, 1952,
˜
1654, 1609, 1553, 1344, 1222 cm–1. MS (70 eV, EI): m/z (%) = 199
(45.81) [M+], 131 (100).
1
ether/ethyl acetate, 5:1) as a liquid. H NMR (300 MHz, CDCl3):
δ = 5.08 (quint, J = 6.6 Hz, 1 H, C=CH), 4.69–4.57 (m, 2 H,
C=CH2), 3.62 (t, J = 6.2 Hz, 2 H, OCH2), 2.08–1.95 (m, 2 H,
CH2C=C), 1.87 (br. s, 1 H, OH), 1.65–1.38 [m, 4 H, C(CH2)
2C] ppm. 13C NMR (75.4 MHz, CDCl3): δ = 208.5, 89.7, 74.7, 62.6,
N-(Buta-2,3-dien-1-yl)-2-furamide (4c): The reaction of CuI
(190.5 mg, 1.00 mmol), paraformaldehyde (480.0 mg, 15.98 mmol),
3c (1.4875 g, 9.97 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 4c[9a] (1.3740 g,
32.1, 27.9, 25.2 ppm. IR (neat): ν = 3324, 2935, 2861, 1956, 1437, 84%) after purification (eluent for chromatography: petroleum
˜
1057 cm–1. MS (70 eV, EI): m/z (%) = 94 (2.20) [M+ – H2O], 79
(100).
ether/ethyl acetate, 4:1 to 2:1) as a liquid. 1H NMR (300 MHz,
CDCl3): δ = 7.42–7.36 (m, 1 H of furan group), 7.10–7.03 (m, 1 H
of furan group), 6.64 (br. s, 1 H, NH), 6.44–6.40 (m, 1 H of furan
group), 5.25 (quint, J = 6.3 Hz, 1 H, C=CH), 4.82 (dt, J = 6.6,
3.3 Hz, 2 H, C=CH2), 4.03–3.93 (m, 2 H, CH2) ppm. 13C NMR
(75.4 MHz, CDCl3): δ = 208.0, 158.1, 147.8, 143.8, 114.1, 111.9,
Penta-3,4-dienylbenzene (2w): The reaction of CuI (190.9 mg,
1.00 mmol), paraformaldehyde (481.0 mg, 16.02 mmol), 1w
(1.3104 g, 10.06 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2w[11l] (0.9123 g,
63%) after purification (eluent for chromatography: petroleum
87.6, 77.5, 37.1 ppm. IR (neat): ν = 3305, 1958, 1645, 1593, 1572,
˜
1523, 1474, 1294, 1184, 1013 cm–1. MS (70 eV, EI): m/z (%) = 163
1
ether) as a liquid. H NMR (300 MHz, CDCl3): δ = 7.32–7.13 (m,
(15.91) [M+], 95 (100).
5 H, ArH), 5.14 (quint, J = 6.6 Hz, 1 H, C=CH), 4.71–4.62 (m, 2
H, C=CH2), 2.72 (t, J = 8.0 Hz, 2 H, ArCH2), 2.37–2.24 (m, 2 H,
N-(Buta-2,3-dien-1-yl)-2,5-dimethyl-3-furamide (4d): The reaction
CH2C=C) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 208.5, 141.7, of CuI (133.2 mg, 0.70 mmol), paraformaldehyde (336.7 mg,
128.5, 128.3, 125.8, 89.4, 75.1, 35.4, 30.0 ppm. IR (neat): ν = 3027,
11.21 mmol), 3d (1.2404 g, 7.00 mmol), and iPr2NH (1.4 mL, d =
0.716 gmL–1, 1.0024 g, 9.91 mmol) in dioxane (10.5 mL) afforded
4d[9a] (1.1191 g, 84%) after purification (eluent for chromatog-
raphy: petroleum ether/ethyl acetate, 5:1 to 3:1) as a liquid. 1H
NMR (300 MHz, CDCl3): δ = 5.99 (s, 1 H of furan group), 5.93
(br. s, 1 H, NH), 5.32–5.20 (m, 1 H, C=CH), 4.88–4.78 (m, 2 H,
C=CH2), 3.98–3.89 (m, 2 H, CH2), 2.51 (s, 3 H, CH3), 2.21 (s, 3
H, CH3) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 207.9, 163.9,
155.0, 149.8, 115.8, 103.9, 88.1, 77.6, 37.1, 13.3, 13.2 ppm. IR
˜
2922, 2855, 1955, 1603, 1496, 1453 cm–1. MS (70 eV, EI): m/z (%)
= 144 (9.27) [M+], 91 (100).
2-(Buta-2,3-dienyloxy)benzaldehyde (2x): The reaction of CuI
(143.4 mg, 0.75 mmol), paraformaldehyde (480.9 mg, 16.01 mmol),
1x (1.6028 g, 10.01 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 2x[11m] (1.0189 g,
58%) by double chromatography on silica gel (first round: petro-
leum ether/ethyl acetate, 20:1; second round: petroleum ether/ethyl
(neat): ν = 3324, 2922, 1957, 1637, 1586, 1523, 1227, 1125 cm–1.
˜
1
acetate, 30:1) as a liquid. H NMR (300 MHz, CDCl3): δ = 10.50
MS (70 eV, EI): m/z (%) = 191 (39.56) [M+], 123 (100).
(s, 1 H, CHO), 7.82 (d, J = 8.1 Hz, 1 H, ArH), 7.52 (t, J = 7.8 Hz,
1 H, ArH), 7.07–6.93 (m, 2 H, ArH), 5.41 (quint, J = 6.6 Hz, 1 H,
N-(Buta-2,3-dien-1-yl)-5-nitro-2-furamide (4e): The reaction of CuI
H, (191.2 mg, 1.00 mmol), paraformaldehyde (481.6 mg, 16.04 mmol),
3e (1.9434 g, 10.01 mmol), and iPr2NH (2.0 mL, d = 0.716 gmL–1,
1.432 g, 14.15 mmol) in dioxane (15 mL) afforded 4e[9a] (1.0950 g,
C=CH), 4.95–4.81 (m,
2 H, C=CH2), 4.72–4.60 (m, 2
OCH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 209.5, 189.7,
160.7, 135.7, 128.3, 125.2, 120.9, 113.0, 86.5, 77.0, 66.2 ppm. IR
(neat): ν = 1957, 1685, 1597, 1481, 1456, 1397, 1377, 1283, 1236, 53%) after purification (eluent for chromatography: petroleum
˜
1217, 1189, 1161, 1120 cm–1. MS (70 eV, EI): m/z (%) = 174 (3.28)
ether/ethyl acetate, 5:1 to 3:1) as a solid, m.p. 94–95 °C (petroleum
[M+], 121 (100).
ether/ethyl acetate). 1H NMR (300 MHz, CDCl3): δ = 7.37 (d, J =
6
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CuI-Catalyzed Synthesis of Functionalized Terminal Allenes
3.6 Hz, 1 H of furan group), 7.27 (d, J = 3.9 Hz, 1 H of furan
group), 6.80 (br. s, 1 H, NH), 5.30 (quint, J = 6.3 Hz, 1 H, C=CH),
Ethyl 4-(Buta-2,3-dien-1-ylamino)-4-oxobutanoate (4j): The reaction
of CuI (190.6 mg, 1.00 mmol), paraformaldehyde (480.9 mg,
4.92 (dt, J = 6.6, 3.3 Hz, 2 H, C=CH2), 4.11–4.02 (m, 2 H, 16.01 mmol), 3j (1.8388 g, 10.04 mmol), and iPr2NH (2.0 mL, d =
CH2) ppm. 13C NMR (75.4 MHz, CDCl3): δ = 208.3, 156.0, 151.1, 0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
147.9, 116.0, 112.4, 87.0, 78.1, 37.7 ppm. IR (neat): ν = 3312, 1953, 4j[9a] (1.2747 g, 64%) after purification (eluent for chromatography:
˜
1650, 1551, 1484, 1350, 1268, 1058, 1016 cm–1. MS (70 eV, EI): m/z
petroleum ether/ethyl acetate, 2:1 to 1:1) as a liquid. 1H NMR
(300 MHz, CDCl3): δ = 6.11 (br. s, 1 H, NH), 5.15 (quint, J =
6.3 Hz, 1 H, C=CH), 4.78 (dt, J = 6.6, 3.3 Hz, 2 H, C=CH2), 4.09
(q, J = 7.2 Hz, 2 H, OCH2), 3.83–3.75 (m, 2 H, NCH2), 2.61 (t, J
= 6.8 Hz, 2 H, CCH2C), 2.45 (t, J = 6.9 Hz, 2 H, CCH2C), 1.21
(t, J = 7.2 Hz, 3 H, CH3) ppm. 13C NMR (75.4 MHz, CDCl3): δ =
207.9, 172.9, 171.3, 87.8, 77.3, 60.6, 37.5, 30.8, 29.5, 14.0 ppm. IR
(%) = 208 (44.46) [M+], 140 (100).
N-(Buta-2,3-dien-1-yl)thiophene-2-carboxamide (4f): The reaction
of CuI (191.0 mg, 1.00 mmol), paraformaldehyde (481.4 mg,
16.03 mmol), 3f (1.6679 g, 10.09 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
4f[9a] (1.4457 g, 80%) after purification (eluent for chromatography:
petroleum ether/ethyl acetate, 5:1 to 3:1) as a liquid. 1H NMR
(400 MHz, CDCl3): δ = 7.52 (dd, J = 4.0, 1.2 Hz, 1 H of thienyl
group), 7.46 (dd, J = 5.0, 1.0 Hz, 1 H of thienyl group), 7.06 (dd,
J = 4.8, 3.6 Hz, 1 H of thienyl group), 6.35 (br. s, 1 H, NH), 5.30
(quint, J = 6.4 Hz, 1 H, C=CH), 4.87 (dt, J = 6.84, 3.2 Hz, 2 H,
C=CH2), 4.06–3.98 (m, 2 H, CH2) ppm. 13C NMR (75.4 MHz,
CDCl3): δ = 208.0, 161.8, 138.8, 129.9, 128.0, 127.5, 87.8, 77.5,
(neat): ν = 3305, 1958, 1733, 1650, 1542, 1165, 1037 cm–1. MS
˜
(70 eV, EI): m/z (%) = 197 (6.51) [M+], 101 (100).
Procedure for the Synthesis of Buta-2,3-dien-1-ol. Method 1: To a
2 L oven-dried three-neck round-bottom flask equipped with a
magnetic stirring bar, a reflux condenser, and a thermometer were
added CuI (38.1 g, 0.200 mol), paraformaldehyde (19.2 g,
0.639 mol), THF (800 mL), iPr2NH (80.0 mL, d = 0.716 gmL–1,
57.3 g, 0.566 mol), and propargyl alcohol (24.0 mL,
d =
37.9 ppm. IR (neat): ν = 3306, 1957, 1625, 1539, 1510, 1420, 1352,
˜
0.949 gmL–1, 22.8 g, 0.406 mol) in open air. After the addition, the
resulting mixture was heated for 24 h in an oil bath at 85 °C with-
out protection under an inert atmosphere. After cooling to room
temperature, the dark-brown solution was concentrated by rotary
evaporation (Ͻ 20 °C/4.8 kPa). The mixture was diluted with di-
ethyl ether (300 mL) followed by filtration through a short column
of silica gel [height = 5.0 cm, ø = 9.0 cm, diethyl ether (5 ϫ
50 mL)]. Then the residue was transferred to a 1 L Erlenmeyer flask
equipped with a magnetic stirring bar and a saturated NaCl aque-
ous (300 mL). Hydrochloric acid (12 n) was added slowly until pH
2–3 (about 20 mL). The mixture was filtered through a short col-
1293 cm–1. MS (70 eV, EI): m/z (%) = 179 (24.17) [M+], 111 (100).
N-(Buta-2,3-dien-1-yl)adamantane-1-carboxamide (4g): The reac-
tion of CuI (190.8 mg, 1.00 mmol), paraformaldehyde (481.2 mg,
16.02 mmol), 3g (2.1697 g, 9.98 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
4g[9a] (1.4671 g, 64%) after purification (eluent for chromatog-
raphy: petroleum ether/ethyl acetate, 8:1 to 5:1) as a solid, m.p.
111–113 °C (petroleum ether/ethyl acetate). 1H NMR (300 MHz,
CDCl3): δ = 5.77 (br. s, 1 H, NH), 5.27–5.16 (m, 1 H, C=CH), 4.84
(dt, J = 6.9, 3.5 Hz, 2 H, C=CH2), 3.85–3.77 (m, 2 H, NCH2),
2.07–1.98 (m, 3 H, 3 ϫ CH), 1.84 (d, J = 2.7 Hz, 6 H, 3 ϫ CH2), umn of quartz sand [hight = 5.0 cm, diameter = 10.0 cm, diethyl
1.78–1.61 (m, 6 H, 3 ϫ CH2) ppm. 13C NMR (75.4 MHz, CDCl3): ether (3 ϫ 100 mL)], and transferred to a separatory funnel. The
δ = 207.7, 177.7, 88.3, 77.7, 40.6, 39.2, 36.9, 36.5, 28.1 ppm. IR aqueous layer was separated and extracted with diethyl ether (4 ϫ
(neat): ν = 3361, 2908, 2848, 1954, 1632, 1517, 1268 cm–1. MS 150 mL). The combined organic layer was dried with anhydrous
˜
(70 eV, EI): m/z (%) = 231 (48.40) [M+], 135 (100).
MgSO4 (50 g). After filtration and concentration through evapora-
tion (Ͻ 20 °C/4.8 kPa), the product was carefully distilled under
vacuum. The main fraction was collected at 54–56 °C (3.8 kPa) to
afford buta-2,3-dien-1-ol[10d] (12.4 g, 44%) as a light yellow liquid,
with additional fractions of less pure material. 1H NMR
(300 MHz, CDCl3): δ = 5.24 (quint, J = 6.5 Hz, 1 H, C=CH), 4.75
(dt, J = 6.6, 3.3 Hz, 2 H, C=CH2), 4.05 (dt, J = 6.0, 3.0 Hz, 2 H,
CH2), 3.35 (br. s, 1 H, OH) ppm. 13C NMR (75.4 MHz, CDCl3): δ
Ethyl 2-(Buta-2,3-dien-1-ylamino)-2-oxoacetate (4h): The reaction
of CuI (190.9 mg, 1.00 mmol), paraformaldehyde (480.7 mg,
16.01 mmol), 3h (1.5517 g, 10.00 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
4h[9a] (0.8105 g, 48%) after purification (eluent for chromatog-
raphy: petroleum ether/ethyl acetate, 4:1) as a liquid. 1H NMR
(300 MHz, CDCl3): δ = 7.33 (br. s, 1 H, NH), 5.25 (quint, J =
6.3 Hz, 1 H, C=CH), 4.90 (dt, J = 6.6, 3.3 Hz, 2 H, C=CH2), 4.36
(q, J = 7.2 Hz, 2 H, OCH2), 3.99–3.90 (m, 2 H, NCH2), 1.39 (t, J
= 7.2 Hz, 3 H, CH3) ppm. 13C NMR (75.4 MHz, CDCl3): δ =
= 207.8, 90.5, 76.4, 59.9 ppm. IR (neat): ν = 3331, 1955, 1009 cm–1.
˜
MS (70 eV, EI): m/z (%) = 70 (13.41) [M+], 55 (100).
Method 2: To an oven-dried high-pressure autoclave (500 mL)
equipped with a magnetic stirring bar were added CuI (3.8 g,
0.020 mol), paraformaldehyde (9.6 g, 0.320 mol), THF (400 mL),
iPr2NH (40.0 mL, d = 0.716 gmL–1, 28.6 g, 0.283 mol), and propar-
gyl alcohol (12.0 mL, d = 0.949 gmL–1, 11.4 g, 0.203 mol). After
the addition, the resulting mixture was sealed and heated for 16 h
in an oil bath at 140 °C. After cooling to room temperature, and
purified following the workup procedure as for Method 1, buta-
2,3-dien-1-ol[10d] (7.484 g, 53%) was afforded as a light yellow li-
quid upon vacuum distillation [b.p.48–51 °C (2.7–3.2 kPa)].
208.1, 160.4, 156.2, 86.7, 77.9, 63.1, 37.8, 13.9 ppm. IR (neat): ν =
˜
3321, 1958, 1735, 1685, 1527, 1299, 1202 cm–1. MS (70 eV, EI): m/z
(%) = 169 (28.72) [M+], 53 (100).
Ethyl 3-(Buta-2,3-dien-1-ylamino)-3-oxopropanoate (4i): The reac-
tion of CuI (190.0 mg, 1.00 mmol), paraformaldehyde (480.5 mg,
16.00 mmol), 3i (1.7074 g, 10.09 mmol), and iPr2NH (2.0 mL, d =
0.716 gmL–1, 1.432 g, 14.15 mmol) in dioxane (15 mL) afforded
4i[9a] (0.5183 g, 28%) after purification (eluent for chromatography:
petroleum ether/ethyl acetate, 4:1 to 2:1) as a liquid. 1H NMR
(300 MHz, CDCl3): δ = 7.28 (br. s, 1 H, NH), 5.23 (quint, J =
6.3 Hz, 1 H, C=CH), 4.86 (dt, J = 6.6, 3.3 Hz, 2 H, C=CH2), 4.20
(q, J = 7.1 Hz, 2 H, OCH2), 3.94–3.85 (m, 2 H, NCH2), 3.32 (s, 2
H, CH2CO), 1.30 (t, J = 7.1 Hz, 3 H, CH3) ppm. 13C NMR
(75.4 MHz, CDCl3): δ = 208.0, 169.4, 164.8, 87.5, 77.6, 61.5, 41.0,
Supporting Information (see footnote on the first page of this arti-
1
cle): H and 13C NMR spectra for the products.
Acknowledgments
37.6, 14.0 ppm. IR (neat): ν = 3305, 1958, 1739, 1652, 1546, 1156,
Financial support from the National Basic Research Program of
China (grant number 2009CB825300) and National Natural Sci-
˜
1028 cm–1. MS (70 eV, EI): m/z (%) = 183 (35.75) [M+], 70 (100).
Eur. J. Org. Chem. 0000, 0–0
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H. Luo, S. Ma
FULL PAPER
[6]
[7]
[8]
ence Foundation of China (NSFC) (grant number 21232006) are
greatly appreciated. The authors thank Li Qiankun for reproducing
the results of Table 2 (Entry 9), Table 3 (Entry 3), and Table 4 (En-
try 7).
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Received: December 16, 2012
Published Online: ᭿
8
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/KAP1
Date: 26-03-13 17:00:29
Pages: 9
CuI-Catalyzed Synthesis of Functionalized Terminal Allenes
Copper Catalysis
H. Luo, S. Ma* ................................ 1–9
CuI-Catalyzed Synthesis of Functionalized
Terminal Allenes from 1-Alkynes
Keywords: Synthetic methods / Hetero-
geneous catalysis / Copper / Alkynes / All-
enes
A practical reaction for the CuI-catalyzed
synthesis of terminal allenes from terminal
alkynes, paraformaldehyde, and iPr2NH
was developed.
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