Yb(OTf)3-catalyzed propargylation and allenylation of 1,3-dicarbonyl derivatives with propargylic alcohols: one-pot synthesis of multi-substituted furocoumarin

Article abstract of DOI:10.1016/j.tet.2007.08.114

A highly efficient and mild Lewis acid-catalyzed coupling reaction of 1,3-dicarbonyl compounds with propargylic alcohols has been established. Selective propargylation or allenylation products are obtained depending on the nature of propargylic alcohols.

Full text of DOI:10.1016/j.tet.2007.08.114

Tetrahedron 63 (2007) 11636–11643
Yb(OTf) -catalyzed propargylation and allenylation of
3
1,3-dicarbonyl derivatives with propargylic alcohols:
one-pot synthesis of multi-substituted furocoumarin
a
Wen Huang, Jialiang Wang, Quansheng Shen and Xigeng Zhou
a
a
a,b,*
a
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials,
Fudan University, Shanghai 200433, People’s Republic of China
b
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry,
Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
Received 15 July 2007; revised 26 August 2007; accepted 31 August 2007
Available online 6 September 2007
Abstract—A highly efficient and mild Lewis acid-catalyzed coupling reaction of 1,3-dicarbonyl compounds with propargylic alcohols has
been established. Selective propargylation or allenylation products are obtained depending on the nature of propargylic alcohols. In addition,
catalytic quantities of Yb(OTf) can also effectively promote the propargylation and allylation of 4-hydroxycoumarins at the 3-position. By
3
applying this reaction as the key step, a multi-substituted furocoumarin can easily be synthesized in a one-pot procedure. The advantages of
this method are broad scope, mild conditions, and easy handling since water is the only side product.
Ó 2007 Elsevier Ltd. All rights reserved.
4
5
1
. Introduction
Very recently, Cadierno et al. and Sanz et al. found that
Brønsted acids were effective as catalysts for the direct substi-
tution of the hydroxyl group in propargylic alcohols with
1,3-dicarbonyl compounds. Nevertheless, alkyl-substituted
propargylicalcoholsareineffectivesubstratestherein;further,
these reactions are generally performed under the refluxing
reaction conditions. Although some catalytic methodologies
for the direct hydroxyl substitution of propargylic alcohols in
the presence of Lewis acid or other catalysts have been re-
portedrecently, theuseof1,3-dicarbonylcompoundsasnucle-
Propargyl- and allenyl-substituted carbonyl compounds are
important building blocks in organic synthesis due to various
transformations of the alkyne/allene and carbonyl into dif-
ferent functional groups. Among the numerous works de-
voted to these compounds, those on new synthetic methods
are very topical. The major goal is to prepare complex com-
pounds with required structures and/or to meet several desir-
able features including the cheap and readily available
starting materials, atom-economy, mild reaction conditions,
simple manipulation, and environmentally friendly cata-
lysts. On the other hand, the alkylation of 1,3-dicarbonyl
compounds is an important strategy for the formation of
C–C bonds in organic synthesis. Recently, considerable in-
terest has been focused on alkylation of 1,3-dicarbonyl com-
6
–8
ophiles has not been well established in any of these works.
Given that Yb(OTf) was an efficient catalyst for alkylation
and allylation of 1,3-dicarbonyl compounds using alcohols
as electrophiles directly, we are interested in further revealing
the possibility of direct propargylation of 1,3-dicarbonyl com-
pounds with alcohols catalyzed by Yb(OTf) and examining
3
theversatilityofthepropargyl-substituted1,3-dicarbonylcom-
pounds. Herein we report an efficient Yb(OTf) -catalyzed
3
1
–3
pounds using alcohols as electrophiles,
several potential advantages, such as the wide availability
since it offers
9
3
of the starting materials and the generation of H O as the
2
propargylation or allenylation of 1,3-dicarbonyl compounds
and 4-hydroxycoumarins with propargylic alcohols, allow-
ing the easy preparation of useful synthetic intermediates
for various applications and representing the first example
of Lewis acid-catalyzed propargylation and allenylation of
only side product. Such strategy has been elegantly applied
to synthesis of allyl and benzyl-substituted 1,3-dicarbonyl
compounds. However, to our surprise, analogous propargyl-
ation reaction remains little explored.
1
,3-dicarbonyl derivatives with propargylic alcohols.
2
. Results and discussion
Keywords: Propargylic alcohols; 1,3-Dicarbonyl compounds; Coumarins;
Lewis acid catalysis; Substitution.
Firstly, we investigated the Yb(OTf) -catalyzed direct sub-
3
stitution of the hydroxyl group of secondary propargylic
*
Corresponding author. Tel.: +86 21 6564 3769; fax: +86 21 6564 1740;
e-mail: xgzhou@fudan.edu.cn
0
040–4020/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.08.114

W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
11637
alcohols 1 with various 1,3-dicarbonyl compounds 2. The re-
sults are summarized in Table 1. In the presence of 5 mol %
Yb(OTf) in nitromethane at room temperature, the reaction
3
smoothly proceeded to give the corresponding coupling
products in high yields with complete regioselectivities in
the propargylic position (Table 1, entries 1, 2, 5 and 6).
The reaction of 1a with low acidity keto-ester compounds
of 1,3-dicarbonyl compounds with propargylic alcohols 1a
a
3
Table 1. Yb(OTf) -catalyzed propargylation of various 1,3-dicarbonyl compounds with propargylic alcohols
O
O
OH
O
O
R4
5
mol% Yb(OTf)3
CH NO , RT
+
R3
R5
R1
R3
Ph
R5
O
3
2
R2
R4
2
R1
O
1
3
R2
O
O
O
O
O
O
O
O
O
O
Ph
OEt Ph
OEt
2a
2b
2c
2d
2e
2f
b
Yield (%) Entry 1 R
b
Yield (%)
Entry 1 R
1
R
2
2
Time (h)
Product
1
R
2
2
Time (h)
Product
O
O
O
O
1
2
3
4
5
6
7
8
1a Ph
1a Ph
1a Ph
1a Ph
1a Ph
1a Ph
Ph 2a 0.5
Ph 2b 0.5
Ph 2c 2
Ph 2d 1
Ph 2e 0.5
Ph 2f 1
Ph 2a 1
Ph 2b 1
92
96
84
86
90
86
87
90
9
1c 4-Cl–C
6
H
H
4
Ph 2a 1
85
92
75
51
90
92
55
82
Ph
Ph 3ca
Ph 3aa
Cl
Cl
O
O
O
O
Ph
O
Ph
Ph
Ph
10 1c 4-Cl–C
6
4
Ph 2b 1
Ph
O
Ph 3cb
Ph 3ab
O
O
O
c
OEt
Ph
Ph
Ph
11 1d 2-Thienyl Ph 2b 0.5
Ph
Ph 3ac
S
Ph 3db
O
O
O
c
Ph
OEt
Ph
12 1e 2-Furyl
Ph 2b 1
Bu 2a 1
Bu 2b 0.5
Ph 2b 2
Ph
O
Ph 3ad
O
Ph 3eb
O
O
O
13 1f Ph
Ph
Ph
Ph 3ae
Bu 3fa
O
O
O
O
O
c
Ph
Ph
Ph
14 1f Ph
Ph 3af
Ph
O
Ph
Bu 3fb
O
O
O
d
15
Ph
1b 4-Me–C
6
H
4
1g Pr
Ph3ba
Ph 3gb
Me
Me
O
O
O
Ph
Ph
d
16
1b 4-Me–C
6
H
4
1h Ph
H
2b 2
Ph
Ph
Ph
Ph 3bb
3 2
(0.025 mmol) in 2 mL CH NO at room temperature.
3hb
a
b
c
d
Reaction conditions: 1 (0.5 mmol), 2 (0.75 mmol), Yb(OTf)
Isolated yields.
Around 1:1 mixture of diastereoisomers.
3
ꢀ
The reaction was carried out at 50 C.

11638
W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
can also give quickly the desired product in high yields (Ta-
ble 1, entries 3 and 4). However, treatment of 1a with lower
acidic diethyl malonate compounds under the same reaction
conditions failed to get the desired product. To explore the
Table 2. Yb(OTf)
with tertiary propargylic alcohols
3
-catalyzed allenylation of 1,3-dicarbonyl compounds
a
O
O
OH
Ph
1
O
O
R3
Ph
R3
R2
5
mol% Yb(OTf)3
CH3NO2, RT
R4
scope of the Yb(OTf) -catalyzed propargylation of 1,3-di-
3
+
Ph
R3
R3
carbonyl compounds, the reaction was also carried out
with other propargylic alcohols. Various aryl-substituted
propargylic alcohols smoothly reacted with 1,3-dicarbonyl
compounds to give the propargylation products in high
yields and complete regioselectivities (Table 1, entries 7–
R2
R4
Ph
2
4
R2 = Ph, 1i
R2 = Bu, 1j
1
0), while heteroaromatic-substituted propargylic alcohols
b
Yield (%)
Entry
1
2
Time (h)
Product
regioselectively afforded the desired products only in mod-
erate yields (Table 1, entries 11 and 12). Variation of the
alkyne substituents from aryl to alkyl did not affect the yields
1
2
3
4
5
1i
1i
1i
1j
1j
2a
2b
2e
2b
2e
0.5
0.5
0.5
1
4ia
4ib
4ie
4jb
4je
53
75
80
86
82
(
Table 1, entries 1 vs 13 and 2 vs 14).
1
In contrast to the previous observation in the Brønsted acid
catalytic system, where the secondary alkyl-substituted
propargylic alcohols did not react with 1,3-dicarbonyl com-
a
Reaction conditions: 1
0.025 mmol) in 2 mL CH
(0.5 mmol),
2
NO at room temperature.
(0.75 mmol), Yb(OTf)
3
(
Isolated yields.
3
2
b
5
pounds, the propyl-substituted propargylic alcohol afforded
the desired product in moderate yield in the present Lewis
acid catalytic system. However, the yield was lower than
those of the corresponding aryl-substituted propargylic alco-
hols, possibly due to the absence of the additional delocal-
ization of the aromatic ring leading to the low stability of
the resulting propargylic cationic intermediate (Table 1, en-
try 15). The structure of 3gb was confirmed by X-ray diffrac-
tion analysis, which was in good agreement with the
proposed structure (Fig. 1). To the best of our knowledge,
this represents the first example of the coupling of alkyl-
substituted propargylic alcohols with 1,3-dicarbonyl com-
pounds. In addition, the reaction of terminal propargylic
alcohol 1h with 2b also gave the coupling product 3hb in
high yield and complete regioselectivity by increasing the
reaction temperature (Table 1, entry 16).
alcohols with 1,3-dicarbonyl compounds, we were interested
in studying the reactivity of tertiary propargylic alcohols to-
ward 1,3-dicarbonyl compounds. Table 2 shows the typical
results. Significantly, in these cases a regioselective allenyl-
ation instead of propargylation took place affording allene
derivatives 4 in moderate to good yields. These results seem
to indicate that all these reactions proceed through the forma-
tion of a cationic species, and the regioselectivity of nucleo-
philic trapping depends on the structure of propargylic
alcohol (1). The large steric hindrance around the hydroxyl
group (e.g., tertiary alkynols) favors nucleophiles attacking
an allenyl-type cation, forming the allenylation products.
Based on the X-ray crystallographic analysis of 4ie as
depicted in Figure 2, the isomerization of propargyl to
allenyl was unambiguously confirmed.
Carbonyl-functionalized allenes are important building
blocks in organic synthesis. There has been a growing effort
in the past to develop new methods for synthesis of such
highly valuable but challenging compounds under mild con-
ditions from simple and readily available starting mate-
Examples of allenylation of 1,3-dicarbonyl compounds are
very rare. Notably, under the previously reported p-toluene-
sulfonic acid monohydrate catalysis, treatment of propar-
gylic alcohol 1i with 2b gave the conjugated diene–dione
in a good yield due to Meyer–Schuster rearrangement that
1
0
rials. After having established that Yb(OTf)3 is an
efficient catalyst for the coupling of secondary propargylic
5
is different to the present observation.
Figure 1. Molecular structure of compound 3gb.
Figure 2. Molecular structure of compound 4ie.

W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
11639
a
Table 3. Syntheses of coumarin analog by Yb(OTf)
3
-catalyzed allylation/propargylation reaction
HO
OH
OH R1
OH Ph
R'
OH
R1
R'
Ph
Ph
R'
R2
6
1
R2
5
mol% Yb(OTf)3
5 mol% Yb(OTf)3
R"
O
O
Ph
R"
O
O
R"
O
5a-5d
O
7
8
OH
OH
OH
OH
Me
Me
O
O
O
5b
O
O
O
Cl
O
5d
O
5
a
5c
Entry
5
1
Time (h)
Product
Isolated yield (%)
Entry
6
5
1
Time (h)
Product
Isolated
yield (%)
1
2
3
4
5
5a
5a
5a
5c
5d
1a
1d
1f
1a
1a
2
2
2
12
12
7aa
7ad
7af
7ca
7da
85
62
75
76
71
6
7
8
9
10
5b
5a
5c
5d
5b
1a
1
0.5
1
1
0.5
7ba
8a
8c
8d
8b
85
95
89
92
90
6
6
6
6
a
ꢀ
Reaction conditions: 5 (0.5 mmol), alcohols 1 or 6 (0.75 mmol), Yb(OTf)
3
(0.025 mmol) in a mixture of 1 mL CH
3
NO
2
and 1 mL dioxane at 50 C.
The development of new methods for the efficient and selec-
tive preparation of highly substituted coumarins is of great
interest in organic chemistry because of the frequent exis-
tence of such structures in biologically active compounds
and their role as valuable synthetic intermediates for poten-
followed by addition of K CO allowed the isolation of
2 3
multi-substituted furocoumarin 9 in 37% yield. This method
provides a mild and straightforward route to multi-
substituted furocoumarin (Scheme 1). The structure of 9
has been determined by X-ray analysis (Fig. 3).
1
1
tial new pharmaceuticals, especially anticoagulants. Al-
though there are several reports in the literatures about the
allylation of coumarins, most of them need organic halides
1
2
as substrates. Encouraged by the above results, we subse-
quently explored the reaction of 4-hydroxycoumarins with
propargylic and allylic alcohols. As shown in Table 3, 4-hy-
droxycoumarins reacted with alkynols 1a and a catalytic
amount of Yb(OTf) to give propargyl-substituted couma-
3
rins 7aa in good yields (Table 3, entry 1). The reaction is
general for different propargylic alcohols and the selected
coumarins (Table 3, entries 2–6). Similarly, reaction of
1
rivatives 5 in the presence of 5 mol % Yb(OTf) allows the
,3-diphenyl allylic alcohol 6 with 4-hydroxycoumarin de-
3
synthesis of allylated products 8 in good to excellent yields
Table 3, entries 7–10). Thus, a new method for the synthesis
(
of 3-propargyl/allyl-substituted 4-hydroxycoumarins has
been developed from simple alcohol starting materials, using
only a catalytic amount of a Lewis acid with water being the
only side product of the process.
Having successfully developed an efficient propargylation
of 4-hydroxycoumarins with propargylic alcohols, we
finally turned our attention to the application of this method
to a one-pot synthesis of furocoumarin, which is a key struc-
tural unit in many natural compounds such as wedelolactone
Figure 3. Molecular structure of compound 9.
3. Conclusion
1
3
and medicagol. Treatment of 4-hrdroxycoumarin with
propargylic alcohol 1a in the presence of 5 mol % Yb(OTf)3
In summary, we have presented the first example of Lewis
acid-catalyzed propargylation of 1,3-dicarbonyl compounds
Ph
OH
1) 5 mol% Yb(OTf)
3
OH
O
CH3NO2 / Dioxane
(1 / 1), 50 °C
+
Ph
O
37% yield
Ph
O
O
Ph 2) K2CO3, 70 °C
O
5a
1a
9
Scheme 1.

11640
W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
+
with propargylic alcohols. Selective propargylation or alle-
nylation products can be obtained depending on the struc-
tures of propargylic alcohols. In addition, Yb(OTf) can
2H). EI-MS: m/z (relative intensity) 290 (M , 10%), 247
(100).
3
also effectively promote the propargylation and allylation
of 4-hydroxycoumarins at the 3-position. Moreover, we
have developed a simple strategy for the synthesis of
multi-substituted furocoumarins by using the Lewis acid-
catalyzed nucleophilic substitution of propargylic alcohols
as the key step. The advantages of this method are mild con-
ditions, broad scope, and easy handling; further, some differ-
ent selectivities from the Brønsted acid catalytic system are
observed.
4.4.2. 2-(1,3-Diphenyl-2-propynyl)-1,3-diphenylpropane-
ꢀ
1
1,3-dione (3ab). H NMR (CDCl , 400 MHz, 25 C): d 5.16
3
(d, J¼10 Hz, 1H), 5.90 (d, J¼10 Hz, 1H), 7.02 (d, J¼7.1 Hz,
2H), 7.14–7.18 (m, 4H), 7.25–7.30 (m, 4H), 7.36–7.48 (m,
3H), 7.51–7.55 (m, 3H), 7.76 (d, J¼7.6 Hz, 2H), 8.12 (d,
+
J¼7.6 Hz, 2H). EI-MS: m/z (relative intensity): 414 (M ,
2%), 309 (5), 191 (100).
4.4.3. Ethyl 3-oxo-[2-(1,3-diphenyl-2-propynyl)]buta-
noate (3ac). Mixture of two diastereoisomers (ca. 1:1): H
1
ꢀ
NMR (CDCl , 400 MHz, 25 C): d 1.05 (t, J¼6.8 Hz, 3H),
3
4. Experimental
1.26 (t, J¼6.8 Hz, 3H), 2.00 (s, 3H), 2.42 (s, 3H), 3.92–
4
.07 (m, 4H), 4.24 (m, 2H), 4.60–4.66 (m, 2H), 7.18–7.47
+
4
.1. General
(m, 20H). EI-MS: m/z (relative intensity): 320 (M , 2%),
77 (70), 247 (95), 191 (100).
2
1
13
All manipulations were performed in air. H and C NMR
spectra were recorded on a Bruker 400 spectrometer using
the residue of deuterated solvents as the internal standard.
Mass spectra were recorded on a Philips Agilent
MS5973N instrument operating in EI mode. GC–MS analy-
sis was performed using a Hewlett Packard Model HP 6890
Series with HP-5 column. High-resolution mass spectra
were obtained with a JEOL JMS-700 (EI) or JEOL JMS-
HX110A (FAB+) spectrometer. The reactions were moni-
tored by TLC with Huanghai GF254 silica gel. Flash column
chromatography was carried out using 300–400 mesh silica
gel using ethyl acetate and hexane as eluents.
4.4.4. Ethyl 3-oxo-[2-(1,3-diphenyl-2-propynyl)]-3-phe-
nylpropionate (3ad). Mixture of two diastereoisomers (ca.
1:1). H NMR (CDCl , 400 MHz, 25 C): d 0.96 (t,
3
1
ꢀ
J¼7.2 Hz, 3H), 1.22 (t, J¼7.2 Hz, 3H), 3.92 (m, 2H),
4.19–4.25 (m, 2H), 4.86 (d, J¼10.7 Hz, 1H), 4.91–4.98
(m, 3H), 7.10–7.52 (m, 26H), 7.88 (d, J¼7.5 Hz, 2H), 8.12
1
3
ꢀ
(d, J¼7.5 Hz, 2H). C NMR (CDCl , 100 MHz, 25 C):
3
d 192.64, 191.76, 167.26, 166.72, 138.65, 138.61, 136.25,
136.37, 133.57, 131.59, 131.44, 128.88, 128.69, 128.58,
128.54, 128.48, 128.45, 128.13, 128.01, 127.92, 127.87,
127.61, 127.35, 125.82, 122.86, 122.78, 88.95, 88.88,
84.25, 84.22, 61.87, 61.75, 61.52, 61.09, 38.34, 37.94,
14.02, 13.67. EI-MS: m/z (relative intensity): 382 (M ,
2%), 309 (100), 277 (85).
+
4
.2. General experimental procedure for the Yb(OTf)3-
catalyzed propargylation and allenylation of 1,3-dicar-
bonyl compounds with propargylic alcohols
4.4.5. 3-(1,3-Diphenyl-2-propynyl)-3-methylpentane-2,4-
dione (3ae). H NMR (CDCl , 400 MHz, 25 C): d 1.46
1
ꢀ
(s, 3H), 1.92 (s, 3H), 2.39 (s, 3H), 5.22 (s, 1H), 7.27–7.30
Toamixtureofalcohols1(0.5 mmol)and1.5 equivofnucleo-
philes in 2 mL of nitromethane was added 5 mol % Yb(OTf)3
3
1
3
(
16 mg, 0.025 mmol). The reaction mixture was stirred at
(m, 6H), 7.37–7.43 (m, 4H). C NMR (CDCl , 100 MHz,
3
ꢀ
128.22, 128.19, 127.57, 122.75, 88.09, 85.35, 72.11,
room temperature or the corresponding conditions men-
tioned in the text. After completion of the reaction monitored
by GC–MS or TLC, solvent was removed under reduced
pressure. The residuewas purified by a short column chroma-
tography using hexane/ethyl acetate as eluents.
25 C): d 205.99, 203.70, 136.53, 131.58, 129.68, 128.40,
41.91, 27.95, 26.37, 14.80. EI-MS: m/z (relative intensity):
304 (M , 2%), 261 (100).
+
4.4.6. 2-Acetyl-2-(1,3-diphenyl-2-propynyl)cyclopentanone
(3af). Mixture of two diastereoisomers (ca. 1:1). Diastereo-
isomer 1: H NMR (CDCl , 400 MHz, 25 C): d 1.27–1.29
3
4
.3. General experimental procedure for the Yb(OTf)3-
1
ꢀ
(m, 1H), 1.65–1.67 (m, 2H), 1.79–1.88 (m, 1H), 2.12–2.20
catalyzed propargylation and allenylation of 4-hydroxy-
coumarin with propargylic alcohols
(m, 1H), 2.52 (s, 3H), 2.76–2.81 (m, 1H), 5.04 (s, 1H),
7.28–7.32 (m, 6H), 7.38–7.42 (m, 4H). EI-MS: m/z (relative
intensity): 316 (M , 2%), 273 (100), 191 (80).
To a mixture of 1 mL nitromethane and 1 mL dioxane were
added 4-hydroxycoumarin (0.5 mmol), alcohol 1 or 6
+
(
0.75 mmol) and 5 mol % Yb(OTf) (16 mg, 0.025 mmol)
3
ꢀ
1
ꢀ
and the reaction mixture was stirred at 50 C. After comple-
tion of the reaction monitored by GC–MS or TLC, solvent
was removed under reduced pressure. The residue was puri-
fied by a short column chromatography using hexane/ethyl
acetate as eluents.
Diastereoisomer 2: H NMR (CDCl , 400 MHz, 25 C):
3
d 1.77–1.82 (m, 1H), 2.01–2.13 (m, 1H), 2.20 (s, 3H), 2.26–
2.38 (m, 2H), 2.42–2.49 (m, 1H), 2.67–2.73 (m, 1H), 4.92
(s, 1H), 7.25–7.33 (m, 8H), 7.36–7.38 (m, 2H). EI-MS: m/z
+
(relative intensity): 316 (M , 3%), 273 (100), 191 (80).
4
4
.4. Characterization data
4.4.7. 3-[1-(4-Methylphenyl)-3-phenyl-2-propynyl]pen-
ꢀ
1
tane-2,4-dione (3ba). H NMR (CDCl , 400 MHz, 25 C):
3
.4.1. 3-(1,3-Diphenyl-2-propynyl)pentane-2,4-dione
d 1.93 (s, 3H), 2.31 (s, 3H), 2.37 (s, 3H), 4.20 (d,
J¼10.9 Hz, 1H), 4.64 (d, J¼10.9 Hz, 1H), 7.12 (d,
J¼7.9 Hz, 2H), 7.24–7.29 (m, 5H), 7.34–7.36 (m, 2H).
1
ꢀ
3aa). H NMR (CDCl , 400 MHz, 25 C): d 1.92 (s, 3H),
3
(
2
1
.38 (s, 3H), 4.22 (d, J¼11 Hz, 1H), 4.68 (d, J¼11 Hz,
1
3
ꢀ
C NMR (CDCl , 100 MHz, 25 C): d 201.68, 201.58,
3
H), 7.24–7.28 (m, 4H), 7.31–7.37 (m, 4H), 7.38–7.41 (m,

W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
11641
1
1
2
37.42, 135.13, 131.60, 129.53, 128.20, 127.93,
26.59, 122.75, 88.29, 84.72, 75.67, 29.65, 29.33, 28.67,
1.02. EI-MS: m/z (relative intensity): 304 (M , 5%), 261
4.4.13. 3-(1-Phenyl-2-heptynyl)pentane-2,4-dione (3fa).
H NMR (CDCl , 400 MHz, 25 C): d 0.88 (t, J¼7.3 Hz,
1
ꢀ
3H), 1.35–1.38 (m, 2H), 1.43–1.46 (m, 2H), 1.87 (s, 3H),
3
+
(
100).
2.16 (t, J¼7.2 Hz, 2H), 2.33 (s, 3H), 4.06 (d, J¼11.0 Hz,
1
3
1
H), 4.40 (d, J¼11.0 Hz, 1H), 7.23–7.32 (m, 5H).
C
NMR (CDCl , 100 MHz, 25 C): 202.06, 202.03, 138.96,
ꢀ
128.81, 128.07, 127.59, 85.45, 78.72, 76.15, 37.82, 31.21,
4.4.8. 2-[1-(4-Methylphenyl)-3-phenyl-2-propynyl]-1,3-
diphenylpropane-1,3-dione (3bb). H NMR (CDCl3,
4
3
1
ꢀ
00 MHz, 25 C): d 2.23 (s, 3H), 5.16 (d, J¼10.0 Hz, 1H),
30.85, 28.55, 21.95, 18.45, 13.63. EI-MS: m/z (relative in-
tensity) 270 (M , 2%), 227 (100).
+
5
.90 (d, J¼10.0 Hz, 1H), 6.98 (d, J¼6.9 Hz, 2H), 7.06 (d,
J¼6.9 Hz, 2H), 7.11–7.27 (m, 5H), 7.42–7.46 (m, 5H),
7
.52–7.54 (m, 1H), 7.76 (d, J¼7.3 Hz, 2H), 8.12 (d,
4.4.14. 1,3-Diphenyl-2-(1-phenyl-2-heptynyl)propane-
ꢀ
1
3
ꢀ
d 193.49, 192.49, 137.02, 136.98, 136.48, 136.26, 133.42,
1
J¼7.3 Hz, 2H). C NMR (CDCl , 100 MHz, 25 C):
1,3-dione (3fb). H NMR (CDCl , 400 MHz, 25 C):
3
3
d 0.74 (t, J¼3.5 Hz, 3H), 1.13–1.17 (m, 4H), 1.92–1.94
(m, 2H), 4.92 (dt, J¼2.2, 10.1 Hz, 1H), 5.78 (d, J¼12 Hz,
1H), 7.12–7.14 (m, 1H), 7.21–7.26 (m, 4H), 7.36–7.48 (m,
5H), 7.53–7.55 (m, 1H), 7.70 (d, J¼7.3 Hz, 2H), 8.08 (d,
1
1
3
33.28, 131.34, 129.25, 129.06, 128.80, 128.56, 128.45,
28.36, 127.88, 127.82, 122.93, 89.58, 84.95, 63.20,
8.29, 20.95. EI-MS: m/z (relative intensity): 324
+
+
(
M ꢁCOPh, 30%), 219 (100).
J¼7.3 Hz, 2H). EI-MS: m/z (relative intensity) 394 (M ,
3%), 289 (100).
4
tane-2,4-dione (3ca). H NMR (CDCl , 400 MHz, 25 C):
.4.9. 3-[1-(4-Chlorophenyl)-3-phenyl-2-propynyl]pen-
ꢀ
1
4.4.15. 1,3-Diphenyl-2-(1-propyl-3-phenyl-2-propynyl)-
propane-1,3-dione (3gb). H NMR (CDCl , 400 MHz,
3
1
d 1.96 (s, 3H), 2.37 (s, 3H), 4.16 (d, J¼10.9 Hz, 1H), 4.66
3
ꢀ
(
d, J¼10.9 Hz, 1H), 7.17–7.30 (m, 8H), 7.34–7.36 (m,
25 C): d 0.96 (t, J¼6.8 Hz, 3H), 1.53–1.64 (m, 4H),
1
3
ꢀ
1
2
1
2
H). C NMR (CDCl , 100 MHz, 25 C): d 201.06,
3
3.88–3.90 (m, 1H), 5.56 (d, J¼9.6 Hz, 1H), 6.83–6.96 (m,
00.89, 136.80, 133.60, 131.59, 129.52, 128.98,
28.45, 128.26, 122.39, 87.49, 85.20, 75.55, 37.17, 29.65,
8.60. EI-MS: m/z (relative intensity): 324 (M , 5%), 281
2H), 7.02–7.20 (m, 3H), 7.33–7.56 (m, 6H), 7.98 (d,
J¼7.8 Hz, 2H), 8.08 (d, J¼7.8 Hz, 2H).
1
3
C NMR
(CDCl , 100 MHz, 25 C): d 194.49, 193.50, 137.04,
+
ꢀ
136.67, 133.79, 133.53, 131.42, 129.19, 128.99, 128.91,
3
(
100).
128.79, 128.06, 127.83, 123.25, 90.41, 84.58, 60.56,
35.89, 33.14, 20.79, 13.89. EI-MS: m/z (relative intensity)
4.4.10. 2-[1-(4-Chlorophenyl)-3-phenyl-2-propynyl]-1,3-
diphenylpropane-1,3-dione (3cb). H NMR (CDCl3,
1
+
380 (M , 10%). Anal. Calcd for C H O : C, 85.23; H,
27
24 2
ꢀ
4
00 MHz, 25 C): d 5.16 (d, J¼10.0 Hz, 1H), 5.86 (d,
6.36. Found: C, 84.81; H, 6.15.
J¼10.0 Hz, 1H), 7.00 (d, J¼7.6 Hz, 2H), 7.13–7.30 (m,
7
H), 7.46–7.50 (m, 5H), 7.53–7.55 (m, 1H), 7.76 (d,
4.4.16. 1,3-Diphenyl-2-(1-phenyl-2-propynyl)propane-
ꢀ
1
3
1
J¼7.9 Hz, 2H), 8.12 (d, J¼7.9 Hz, 2H). C NMR (CDCl3,
1,3-dione (3hb). H NMR (CDCl , 400 MHz, 25 C):
3
ꢀ
1
1
1
6
00 MHz, 25 C): d 193.12, 192.29, 137.80, 136.82,
36.24, 133.57, 133.25, 131.35, 129.96, 129.04, 128.87,
28.69, 128.44, 128.06, 127.93, 122.58, 88.76, 85.43,
d 2.18 (d, J¼1.8 Hz, 1H), 4.99 (dd, J¼10.0, 2.3 Hz, 1H),
5.88 (d, J¼10.0 Hz, 1H), 7.10–7.14 (m, 1H), 7.19–7.30
(m, 3H), 7.37–7.56 (m, 7H), 7.69 (d, J¼7.8 Hz, 2H), 8.02
(d, J¼7.8 Hz, 2H). EI-MS: m/z (relative intensity) 338
2.95, 38.05. EI-MS: m/z (relative intensity): 343
+
+
(
M ꢁCOPh, 35%), 239 (50), 105 (100).
(M , 20%), 233 (100).
4
nyl]propane-1,3-dione (3db).
.4.11. 1,3-Diphenyl-2-[3-phenyl-1-(2-thienyl)-2-propy-
H
4.4.17. 3-(Triphenyl-1,2-propadienyl)pentane-2,4-dione
(4ia). H NMR (CDCl , 400 MHz, 25 C): d 2.03 (s,
1
1
ꢀ
6H), 7.236–7.51 (m, 16H). C NMR (CDCl , 100 MHz,
NMR (CDCl3,
3
ꢀ
13
4
00 MHz, 25 C): d 5.52 (d, J¼10.0 Hz, 1H), 5.94 (d,
3
ꢀ
128.74, 128.68, 127.95, 127.83, 126.16, 112.28, 108.01,
J¼10.0 Hz, 1H), 6.84 (m, 1H), 7.01–7.06 (m, 2H), 7.08–
25 C):
d
208.58, 192.14, 135.88, 135.54, 129.19,
7
2
.12 (d, J¼2.7 Hz, 1H), 7.15–7.23 (m, 4H), 7.32–7.35 (m,
H), 7.42–7.51 (m, 3H), 7.57–7.61 (m, 1H), 7.84 (d,
105.49, 31.71, 24.09. EI-MS: m/z (relative intensity) 366
(M , 5%).
1
3
+
J¼8.7 Hz, 2H), 8.12 (d, J¼8.7 Hz, 2H). C NMR (CDCl3,
ꢀ
1
1
1
8
3
00 MHz, 25 C): d 193.05, 192.57, 142.27, 136.86,
36.45, 134.56, 132.98, 132.32, 130.74, 130.17, 129.62,
28.95, 128.20, 127.72, 127.38, 126.07, 124.16, 122.64,
8.69, 85.40, 62.79, 33.38. EI-MS: m/z (relative intensity)
4.4.18. 2-[(Triphenyl-1,2-propadienyl)]-1,3-diphenylpro-
ꢀ
1
pane-1,3-dione (4ib). H NMR (CDCl , 400 MHz, 25 C):
3
d 6.59 (s, 1H), 7.13–7.35 (m, 12H), 7.42 (d, J¼7.3 Hz,
+
13
15 (M ꢁCOPh, 100).
4H), 7.90 (d, J¼7.3 Hz, 4H). C NMR (CDCl , 100 MHz,
3
ꢀ
2
5 C): d 210.19, 193.97, 135.73, 134.94, 133.41, 129.07,
4.4.12. 1,3-Diphenyl-2-[3-phenyl-1-(2-furanyl)-2-propy-
nyl]propane-1,3-dione (3eb). H NMR (CDCl , 400 MHz,
128.76, 128.69, 128.51, 128.33, 127.76, 127.63, 126.68,
125.81, 115.92, 104.96, 58.43.
1
3
ꢀ
2
1
1
5 C): d 5.30 (d, J¼10.0 Hz, 1H), 6.08 (d, J¼10.0 Hz,
H), 6.22 (m, 1H), 6.28 (d, J¼2.7 Hz, 1H), 7.05–7.52 (m,
4.4.19. 3-Methyl-3-(triphenyl-1,2-propadienyl)pentane-
2,4-dione (4ie). H NMR (CDCl , 400 MHz, 25 C):
1
3
1
ꢀ
d 1.65 (s, 3H), 2.18 (s, 6H), 7.21–7.42 (m, 15H). C NMR
2H), 7.88 (d, J¼7.3 Hz, 2H), 8.10 (d, J¼7.3 Hz, 2H).
C
3
ꢀ
13
NMR (CDCl , 100 MHz, 25 C): d 193.08, 192.47, 150.97,
3
ꢀ
1
1
1
42.27, 136.83, 136.14, 133.77, 133.69, 131.63, 129.16,
29.00, 128.88, 128.64, 128.32, 128.11, 122.71, 110.67,
08.10, 86.37, 84.74, 59.63, 32.65. EI-MS: m/z (relative inten-
(CDCl , 100 MHz, 25 C): d 207.55, 207.28, 135.48,
3
134.17, 129.61, 129.18, 128.31, 128.05, 127.61, 127.28,
126.81, 114.15, 110.00, 68.78, 28.66, 27.40, 20.35.
EI-MS: m/z (relative intensity) 380 (M , 2%), 337 (100).
+
+
sity) 299 (M ꢁCOPh, 30%).

11642
W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
Anal. Calcd for C H O : C, 85.23; H, 6.36. Found: C,
8
J¼2.5, 7.8 Hz, 2H), 7.58 (s, 1H), 7.62 (d, J¼7.3 Hz, 2H),
ꢀ
3
27 24 2
1
3
4.98; H, 6.24.
8.37 (s, 1H).
C NMR (CDCl , 100 MHz, 25 C):
d 163.16, 161.56, 151.22, 142.66, 138.88, 133.05, 131.93,
129.21, 129.06, 128.64, 127.74, 127.23, 123.39, 121.64,
117.07, 113.53, 104.09, 87.67, 86.89, 33.43, 20.41, 19.43.
Anal. Calcd for C H O : C, 82.08; H, 5.30. Found: C,
81.59; H, 5.04. HRMS (EI) calcd for C H O : 380.1412;
26 20 3
found: 380.1414.
4
enyl)pentane-2,4-dione (4je).
.4.20. 3-Methyl-3-(3,3-diphenyl-1-butyl-1,2-propadi-
H
1
NMR (CDCl3,
ꢀ
4
2
1
2
6
00 MHz, 25 C): d 0.84 (t, J¼7.3 Hz, 3H), 1.28–1.32 (m,
2
6 20 3
H), 1.51–1.56 (m, 5H), 2.00–2.10 (m, 8H), 7.23–7.36 (m,
0 H). C NMR (CDCl , 100 MHz, 25 C): d 207.31,
1
3
ꢀ
03.39, 136.40, 128.60, 128.28, 127.59, 113.91, 108.37,
3
9.71, 29.99, 29.26, 27.55, 22.59, 18.96, 14.04. EI-MS: m/z
4.4.26. 7-Chloro-3-[1,3-diphenyl-2-propynyl]-4-hy-
droxy-1-benzopyran-2(H)-one (7da). H NMR (CDCl ,
+
1
(
relative intensity) 360 (M , 2%), 318 (100).
3
ꢀ
4
00 MHz, 25 C): d 5.76 (s, 1H), 7.22–7.52 (m, 10H),
4.4.21. 2-[(3,3-Diphenyl-1-butyl-1,2-propadienyl)]-1,3-
diphenylpropane-1,3-dione (4jb). H NMR (CDCl3,
7.60 (d, J¼7.8 Hz, 2H), 7.82 (d, J¼2.3 Hz, 1H), 8.53 (s,
1
13
ꢀ
1H). C NMR (CDCl , 100 MHz, 25 C): d 162.15,
3
ꢀ
4
2
1
00 MHz, 25 C): d 0.84 (t, J¼7.6 Hz, 3H), 1.31–1.36 (m,
H), 1.54–1.59 (m, 2H), 2.29 (t, J¼7.8 Hz, 2H), 5.99 (s,
H), 7.13–7.26 (m, 14H), 7.41 (t, J¼7.3 Hz, 2H), 7.86 (d,
160.08, 151.07, 138.35, 132.43, 131.93, 129.76, 129.41,
129.19, 128.69, 128.00, 127.24, 123.17, 121.31, 118.07,
117.21, 105.90, 88.18, 86.28, 33.63. Anal. Calcd for
C H ClO : C, 74.52; H 3.91. Found: C, 74.89; H,
1
3
ꢀ
J¼7.3 Hz, 4H). C NMR (CDCl , 100 MHz, 25 C):
3
24 15
3
d 206.19, 194.59, 136.13, 136.01, 133.43, 128.78, 128.71,
3.49. HRMS (EI) calcd for C H ClO : 386.0710; found:
24 15 3
1
3
28.47, 128.33, 127.27, 113.15, 104.35, 61.35, 32.35,
0.03, 22.66, 14.13. EI-MS: m/z (relative intensity) 470
386.0718.
+
(M , 2%). Anal. Calcd for C H O : C, 86.77; H, 6.43.
Found: C, 86.81; H, 6.41. HRMS (EI) calcd for C H O :
4
4.4.27. 3-[1,3-Diphenyl-2-propynyl]-4-hydroxy-6-meth-
yl-pyran-2-one (7ba). H NMR (CDCl , 400 MHz,
3
4 30 2
1
34
30
2
3
ꢀ
70.2246; found: 470.2241.
25 C): d 2.08 (s, 3H), 5.65 (s, 1H), 6.05 (s, 1H), 7.21–
7
.34 (m, 6H), 7.48 (dd, J¼1.8, 7.8 Hz, 2H), 7.60 (d,
1
3
ꢀ
4.4.22. 3-[1,3-Diphenyl-2-propynyl]-4-hydroxy-1-benzo-
pyran-2(H)-one (7aa). H NMR (CDCl , 400 MHz,
J¼7.8 Hz, 2H). C NMR (CDCl , 100 MHz, 25 C):
3
1
d 167.10, 165.62, 161.64, 139.31, 137.21, 131.88, 128.57,
128.43, 127.44, 127.16, 122.91, 102.75, 101.68, 87.77,
84.73, 32.20, 19.77. Anal. Calcd for C H O : C, 79.73;
3
ꢀ
2
5 C): d 5.80 (s, 1H), 7.25–7.38 (m, 8H), 7.50–7.56 (m,
1
3
3
H), 7.62 (dd, J¼1.4, 7.8 Hz, 2H), 8.42 (s, 1H). C NMR
2
1 16 3
ꢀ
(
CDCl , 100 MHz, 25 C): d 162.74, 161.26, 152.75,
3
H, 5.10. Found: C, 79.93; H, 4.95.
1
1
8
38.64, 132.49, 131.95, 129.31, 129.13, 128.67, 127.86,
27.23, 124.19, 123.55, 121.49, 116.61, 116.05, 105.06,
7.95, 86.58, 33.49. EI-MS: m/z (relative intensity) 352
4.4.28. 3-[1,3-Diphenyl-2-allyl]-4-hydroxy-1-benzo-
ꢀ
1
pyran-2(H)-one (8a). H NMR (CDCl , 400 MHz, 25 C):
3
+
(M , 100%), 275 (30). Anal. Calcd for C H O : C 81.80;
2
H 4.58. Found: C, 81.87; H, 4.59.
d 5.50 (d, J¼6.5 Hz, 1H), 6.55 (d, J¼16.0 Hz, 1H), 6.81
4 16 3
(dd, J¼6.0, 16.0 Hz, 1H), 7.22–7.44 (m, 12H), 7.50–7.55
1
3
(
m, 1H), 7.86 (dd, J¼1.5, 7.8 Hz, 1H). C NMR (CDCl ,
3
ꢀ
4
1
4
7
8
2
1
1
.4.23. 3-[3-Phenyl-1-(2-thienyl)-2-propynyl]-4-hydroxy-
-benzopyran-2(H)-one (7ad).
100 MHz, 25 C): d 163.59, 161.26, 152.78, 140.00,
136.42, 133.83, 132.29, 129.29, 128.77, 128.43, 128.14,
128.11, 127.63, 126.67, 124.18, 123.33, 116.65, 116.09,
106.75, 44.14. EI-MS: m/z (relative intensity) 354 (M ,
10%). Anal. Calcd for C H O : C, 81.34; H, 5.12. Found:
C, 81.72; H, 5.22.
1
H
NMR (CDCl3,
ꢀ
00 MHz, 25 C): d 5.99 (s, 1H), 6.96 (t, J¼4.5 Hz, 1H),
+
.22–7.38 (m, 7H), 7.51–7.57 (m, 3H), 7.86 (dd, J¼1.8,
1
3
.2 Hz, 1H), 8.27 (s, 1H). C NMR (CDCl , 100 MHz,
3
24 18 3
ꢀ
29.45, 128.67, 127.12, 125.55, 125.35, 124.26, 123.64,
21.25, 116.66, 115.95, 104.82, 87.32, 85.97, 29.28.
5 C): d 162.40, 161.35, 152.79, 141.84, 132.67, 131.97,
4.4.29. 6,7-Dimethyl-3-[1,3-diphenyl-2-allyl]-4-hydroxy-
1-benzopyran-2(H)-one (8c).
+
1
EI-MS: m/z (relative intensity) 358 (M , 100%), 275 (30).
H NMR (CDCl3,
00 MHz, 25 C): d 2.12 (s, 3H), 2.14 (s, 3H), 5.28 (d,
ꢀ
4
4.4.24. 3-[3-Butyl-1-phenyl-2-propynyl]-4-hydroxy-1-
benzopyran-2(H)-one (7af). H NMR (CDCl , 400 MHz,
J¼8.7 Hz, 1H), 6.51 (d, J¼15.6 Hz, 1H), 6.89 (s, 1H),
6.94 (dd, J¼8.7, 15.6 Hz, 1H), 7.02 (m, 2H), 7.08–7.15
(m, 4H), 7.25–7.28 (m, 4H), 7.61 (s, 1H), 10.41 (s, 1H).
1
3
ꢀ
2
1
7
8
2
1
8
5 C): d 0.93 (t, J¼7.3 Hz, 3H), 1.41–1.48 (m, 2H), 1.53–
.61 (m, 2H), 2.32–2.36 (m, 2H), 5.48 (t, J¼2.3 Hz, 1H),
.22–7.36 (m, 5H), 7.49–7.56 (m, 3H), 7.84 (dd, J¼1.4,
1
3
ꢀ
C NMR (CDCl , 100 MHz, 25 C): d 163.42, 161.27,
3
151.17, 142.61, 141.58, 137.47, 132.44, 131.78, 129.98,
128.54, 128.21, 127.54, 127.28, 126.35, 126.14, 123.47,
116.91, 114.09, 106.73, 43.93, 20.16, 19.42. Anal.
Calcd for C H O : C, 81.65; H, 5.80. Found: C, 80.91;
1
3
.2 Hz, 1H), 8.78 (s, 1H). C NMR (CDCl , 100 MHz,
3
ꢀ
27.58, 127.15, 124.07, 123.46, 116.53, 116.15, 105.11,
9.30, 78.16, 33.10, 30.64, 22.13, 18.61, 13.65. EI-MS:
5 C): d 162.65, 161.22, 152.71, 139.38, 132.28, 128.91,
2
6 22 3
H, 5.56. HRMS (EI) calcd for C H O : 382.1569; found:
26 22 3
382.1565.
+
m/z (relative intensity) 332 (M , 100%), 275 (35). Anal.
Calcd for C H O : C, 79.50; H, 6.06. Found: C, 79.24;
H, 5.89.
2
2 20 3
4.4.30. 7-Chloro-3-[1,3-diphenyl-2-allyl]-4-hydroxy-1-
benzopyran-2(H)-one (8d). H NMR (CDCl , 400 MHz,
1
3
ꢀ
4.4.25. 6,7-Dimethyl-3-[1,3-diphenyl-2-propynyl]-4-hy-
droxy-1-benzopyran-2(H)-one (7ca). H NMR (CDCl ,
25 C): d 5.48 (d, J¼6.8 Hz, 1H), 6.57 (d, J¼15.6 Hz,
13
1
1H), 6.86 (dd, J¼6.8, 15.6 Hz, 1H), 7.18–7.43 (m, 12H),
3
ꢀ
H), 7.06 (s, 1H), 7.25–7.37 (m, 6H), 7.50–7.53 (dd,
4
1
00 MHz, 25 C): d 2.28 (s, 3H), 2.32 (s, 3H), 5.79 (s,
7.86 (d, J¼2.2 Hz, 1H), 8.01 (br s, 1H). C NMR (CDCl ,
3
ꢀ
100 MHz, 25 C): d 163.32, 160.28, 151.06, 139.95,

W. Huang et al. / Tetrahedron 63 (2007) 11636–11643
11643
1
1
1
4
36.41, 133.92, 132.21, 129.76, 129.25, 128.78, 128.13,
28.09, 128.05, 127.62, 126.67, 123.08, 118.13, 117.36,
07.82, 44.20. Anal. Calcd for C H ClO : C, 74.13; H
Maiti, S. Tetrahedron Lett. 2007, 48, 4065; (c) Noji, M.;
Konno, Y.; Ishii, K. J. Org. Chem. 2007, 72, 5161; (d) Reping,
M.; Nachtsheim, B. J.; Kuenkel, A. Org. Lett. 2007, 9, 825; (e)
Reping, M.; Nachtsheim, B. J.; Ieawsuwan, W. Adv. Synth.
Catal. 2006, 348, 1033; (f) Sanz, R.; Mart ꢀı nez, A.; Miguel, D.;
2
4
17
3
.41. Found: C, 74.38; H, 4.38. HRMS (EI) calcd for
C H ClO : 388.0866; found: 388.0856.
2
4
17
3
ꢀ
Alvarez-Guti ꢀe rrez, J. M.; Rodr ꢀı guezb, F. Adv. Synth. Catal.
2006, 348, 1841; (g) Sanz, R.; Miguel, D.; Martinez, A.;
4
pyran-2-one (8b). H NMR (CDCl , 400 MHz, 25 C):
.4.31. 3-[1,3-Diphenyl-2-allyl]-4-hydroxy-6-methyl-
ꢀ
1
ꢀ
Alvarez-Guti ꢀe rrez, J. M.; Rodr ꢀı guezb, F. Org. Lett. 2007, 9,
2027.
3
d 2.08 (s, 3H), 5.18 (d, J¼8.7 Hz, 1H), 6.00 (s, 1H), 6.56
(
7
1
d, J¼15.6 Hz, 1H), 7.02 (dd, J¼8.7, 15.6 Hz, 1H), 7.12–
3. (a) Motokura, K.; Fujita, N.; Mori, K.; Mizugaki, T.; Ebitani,
K.; Kaneda, K. Angew. Chem., Int. Ed. 2006, 45, 2605; (b)
Motokura, K.; Nakagiri, N.; Muzugaki, T.; Ebitani, K.;
Kaneda, K. J. Org. Chem. 2007, 72, 6006.
4. Cadierno, V.; Gimeno, J.; Nebra, N. Adv. Synth. Catal. 2007,
349, 382.
.18 (m, 2H), 7.22–7.27 (m, 4H), 7.37–7.39 (m, 4H),
0.81 (s, 1H). C NMR (CDCl , 100 MHz, 25 C):
1
3
ꢀ
3
d 166.82, 166.09, 160.87, 142.89, 137.75, 131.32, 130.11,
1
28.61, 128.22, 127.76, 127.27, 126.44, 126.14, 104.28,
01.34, 43.43, 19.81. Anal. Calcd for C H O : C, 79.22;
H, 5.70. Found: C, 78.77; H, 5.50.
1
2
1 18 3
ꢀ
5. Sanz, R.; Miguel, D.; Martinez, A.; Alvarez-Guti ꢀe rrez, J. M.;
Rodr ꢀı guezb, F. Org. Lett. 2007, 9, 727.
6. Georgy, M.; Boucard, V.; Campagne, J. M. J. Am. Chem. Soc.
2005, 127, 14180.
1
4
NMR (CDCl , 400 MHz, 25 C): d 4.18 (s, 2H), 7.23–7.56
.4.32. 2-Benzyl-3-phenylfuro[3,2-c]coumarin (9).
ꢀ
H
3
1
3
(
1
m, 13H), 7.86 (d, J¼7.8 Hz, 1H). C NMR (CDCl3,
7. (a) Zhan, Z. P.; Yang, W. Z.; Yang, R. F.; Yu, J. L.; Li, J. P.; Liu,
H. J. Chem. Commun. 2006, 3352; (b) Zhan, Z. P.; Yu, J. L.;
Liu, H. J.; Cui, Y. Y.; Yang, R. F.; Yang, W. Z.; Li, J. P.
J. Org. Chem. 2006, 71, 8298.
8. (a) Qin, H. B.; Yamagiwa, N.; Matsunaga, S.; Shibasaki, M.
Angew. Chem., Int. Ed. 2007, 46, 409; (b) Liu, J. H.; Muth,
E.; Fl €o rke, U.; Henkel, G.; Merz, K.; Sauvageau, J.;
Schwake, E.; Dyker, G. Adv. Synth. Catal. 2006, 348, 456;
ꢀ
00 MHz, 25 C): d 157.81, 157.03, 153.24, 152.60,
1
1
1
37.32, 130.62, 129.97, 129.84, 128.91, 128.48, 128.47,
28.23, 126.99, 124.38, 121.88, 120.98, 117.23, 112.88,
09.77, 32.58. EI-MS: m/z (relative intensity) 352(M ,
+
1
C, 81.43; H, 4.51.
0%). Anal. Calcd for C H O : C, 81.80; H, 4.58. Found:
2
4 16 3
(
2
c) Kuninobu, Y.; Ishii, E.; Takai, K. Angew. Chem., Int. Ed.
007, 46, 3296.
Acknowledgements
9
. Huang, W.; Wang, J. L.; Shen, Q. S.; Zhou, X. G. Tetrahedron
Lett. 2007, 48, 3969.
0. Krause, N.; Hashmi, A. S. K. Modern Allene Chemistry; Wiley-
We thank the NNSF of China and NSF of Shanghai for finan-
cial support.
1
VCH: Weinheim, Germany, 2004; Vols.1 and 2.
11. Staunton, J. Comprehensive Organic Chemistry; Sammes,
P. G., Ed.; Pergamon: Oxford, 1979; Vol. 4.
References and notes
1
2
. Yasuda, M.; Somyo, T.; Baba, A. Angew. Chem., Int. Ed. 2006,
5, 793.
. (a) Kischel, J.; Mertins, K.; Michalik, D.; Zapf, A.; Beller, M.
12. Majumdar, K. C.; Sarkar, S. Tetrahedron 2002, 58, 8501.
13. (a) Li, C. C.; Xie, Z. X.; Zhang, Y. D.; Chen, J. H.; Yang, Z.
J. Org. Chem. 2003, 68, 8400; (b) Risitano, F.; Grassi, G.;
Foti, F.; Bilardo, C. Tetrahedron Lett. 2001, 42, 3503.
4
Adv. Synth. Catal. 2007, 349, 865; (b) Jana, U.; Biswas, S.;