AuCl-catalyzed reaction of ortho-alkynyl(oxo)benzene with benzenediazonium 2-carboxylate as a synthetic method towards anthracene, triptycene, and phthalazine derivatives

Article abstract of DOI:10.1016/j.tet.2007.10.083

The AuCl-catalyzed benzannulation of ortho-alkynylphenyl ketones with benzenediazonium 2-carboxylate proceeded efficiently at 40 °C in (CH₂Cl)₂ and a variety of anthracene derivatives, having a ketone group at 9-position, were produc

Full text of DOI:10.1016/j.tet.2007.10.083

Available online at www.sciencedirect.com
Tetrahedron 64 (2008) 787e796
www.elsevier.com/locate/tet
AuCl-catalyzed reaction of ortho-alkynyl(oxo)benzene with
benzenediazonium 2-carboxylate as a synthetic method towards
anthracene, triptycene, and phthalazine derivatives
Kenichiro Sato a, Menggenbateer a, Toshihiko Kubota a, Naoki Asao a,b,
*
a Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
b Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Received 17 July 2007; accepted 3 October 2007
Available online 25 October 2007
Abstract
The AuCl-catalyzed benzannulation of ortho-alkynylphenyl ketones with benzenediazonium 2-carboxylate proceeded efficiently at 40 ꢀC in
(CH2Cl)2 and a variety of anthracene derivatives, having a ketone group at 9-position, were produced in good to high yields. On the other hand,
the reaction of ortho-alkynylbenzaldehydes with benzenediazonium 2-carboxylate afforded triptycyl ketones. The reactions most probably pro-
ceed through the formation of a zwitterionic intermediate by the gold-induced electrophilic cyclization of ortho-alkynyl(oxo)benzenes, followed
by the cycloaddition of benzyne. In contrast, when the above reaction was carried out at rt in 1,4-dioxane, phthalazine derivative was produced
without the generation of benzyne.
Ó 2007 Elsevier Ltd. All rights reserved.
Keywords: Gold catalyst; Anthracene; Benzyne; Benzannulation
1. Introduction
violently on being scraped or heated). We recently have com-
municated the gold-catalyzed benzannulations between ortho-
alkynylphenyl ketone 1 and 2, which afforded anthryl ketone
product 3 in good to high yields (Scheme 1).4 While exploring
the scope of this reaction, we found that the reaction of ortho-
It is well known that benzynes are important reactive inter-
mediates and many studies on their reactions have been under-
taken in synthetic organic chemistry.1 Particularly, pericyclic
cycloadditions using benzyne, such as the DielseAlder reac-
tion, are one of the most important methods for the construc-
tion of polyaromatic compounds.2 Due to its extraordinary
reactive ability, the reaction is observed with a very wide
range of dienes including simple benzene derivatives or other
aromatic compounds. The transition metal-catalyzed synthetic
methods of polyaromatics with benzynes have also been stud-
ied well. However, to the best of our knowledge, there is no
research on the Lewis acid-catalyzed DielseAlder reaction
with benzyne. As a benzyne precursor, benzenediazonium
2-carboxylate 2 has been often used in organic synthesis3 (cau-
tion: when dry, benzenediazonium 2-carboxylate detonates
R
O2C
O
+
+
AuCl cat.
N2
R'
1
2
O
R
R
O
R
O
N
N
O
R'
O
R'
R = H
3
4
5
R'
* Corresponding author. Tel.: þ81 22 795 3898; fax: þ81 22 795 3899.
E-mail address: asao@mail.tains.tohoku.ac.jp (N. Asao).
Scheme 1. Gold-catalyzed reaction of 1 with 2.
0040-4020/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.10.083

788
K. Sato et al. / Tetrahedron 64 (2008) 787e796
alkynylbenzaldehyde 1 (R¼H) with 2 afforded triptycyl ke-
tone 4 but not anthryl ketone 3. In both reactions, benzyne
would be generated via a thermal decomposition of 2, which
reacted with 1 to give anthracenes 3 or triptycenes 4. Interest-
ingly, however, we noticed that the gold-catalyzed reaction of
1 with 2 proceeded even without generation of benzyne under
lower temperatures and the corresponding phthalazine product
5 was produced. In this paper, we detail the synthetic method
of anthryl ketone 3 together with unprecedented synthetic
approaches to triptycyl ketone 4 and phthalazine derivative 5.5
2.2. Gold-catalyzed benzannulation
Since the model study proceeded smoothly, we next exam-
ined the Lewis acid-catalyzed direct benzannulation between
ortho-alkynyl(oxo)benzenes 1 and benzyne and the results
are summarized in Table 1. When the reaction of (2-phenyl-
ethynyl-phenyl)-p-tolylmethanone 1b (R¼p-MeC6H4, R0¼Ph)
was carried out with 1.8 equiv of 2a in the presence of
10 mol % of AuBr3 in (CH2Cl)2, the reaction proceeded
smoothly at 60 ꢀC for 2 h and the anthracene derivative 3b
was obtained in 55% yield as a sole product (entry 1). Optimi-
zation experiments revealed that the chemical yield was in-
creased up to 81% when the reaction was conducted in the
presence of AuCl catalyst at 40 ꢀC (entries 2e5). Other Lewis
and Brønsted acids, such as Cu(OTf)2, PtCl2, and TfOH, were
not effective. The AuCl-catalyzed reaction also proceeded
well with other differently substituted substrates 1a,cef
(entries 6e10). Interestingly, the reaction of 1a with 2a
produced 3a in 72% yield (entry 6), which is higher than
that of the model reaction mentioned in Eq. 2. Compared
with 1b, the reactions of 1a and 1c gave the corresponding
products in lower yields (entries 5e7). These results would
be ascribed to the fact that an intermediate 8 in Scheme 2
can be stabilized effectively by an electron-donating ability
of R group (vide infra). The reaction of 1d, having a propyl
group instead of an aryl group at the terminus of alkyne,
afforded anthracene derivative 3d in 87% yield (entry 8).
The reaction proceeded well even with the sterically bulky
tert-butyl group (entry 9). When the reaction of 1a was per-
formed in the absence of gold catalyst, no benzannulation
products were obtained at all. This blank test clearly indicates
that a Lewis acid, such as AuCl, is an essential catalyst for the
current transformation.
2. Results and discussion
2.1. Benzannulation with benzo[c]pyrylium salt
Recently, we have reported that gold-catalyzed [4þ2] benz-
annulations between ortho-alkynyl(oxo)benzenes and alkynes
proceeded smoothly in both inter- and intramolecular ways
to give naphthalene compounds in good to high yields.6,7
The reaction likely proceeds through the formation of a benzo-
pyrylium type intermediate, followed by the DielseAlder
addition of alkynes. It occurred to us that benzyne may be
utilized as a partner in the benzannulation reactions. As a pre-
liminary experiment, we initially examined the reaction of
benzyne with an isolable benzo[c]pyrylium salt.8,9 The requi-
site substrate 6 was easily prepared from the corresponding
ortho-alkynyl(oxo)benzene 1a according to the Swager’s
procedure.10 Treatment of 1a with excess amount of TfOH in
CH2Cl2, followed by addition of ether produced 6 in 80%
yield (Eq. 1). Then, the benzannulation reaction of 6 was un-
dertaken with benzenediazonium 2-carboxylate 2a as a precur-
sor of benzyne. As expected, when 6 was treated with
1.8 equiv of 2a in (CH2Cl)2 at 40 ꢀC for 8 h, the reaction pro-
ceeded and an anthracene product 3a, bearing a ketone group
at the C9-position, was obtained in 36% yield (Eq. 2). It seems
that the low yield of 3a is due to the low reactivity as well as
the insolubility of 6 to the solvent. Indeed, the chemical yield
was increased up to 62% by just conducting the reaction at
80 ꢀC for 3 h. These results clearly showed that benzyne
worked as a dienophile in the DielseAlder reaction with benzo-
[c]pyrylium salt 6 and this is a novel synthetic approach to
anthracene compounds.
Table 1
The gold-catalyzed benzannulation between ortho-alkynyl(oxo)benzenes 1
and benzenediazonium 2-carboxylate 2aa
R
R
O2C
Au cat.
(CH2Cl)2
O
+
N2
R'
O
R'
1
2a
3
Entry
1
R
R0
Lewis acid Conditions
3
Yield
b
%
Ph
O
Ph
1
1b p-MeC6H4
1b p-MeC6H4
1b p-MeC6H4
1b p-MeC6H4
1b p-MeC6H4
1a Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
AuBr3
AuCl3
AuCl
60 ꢀC, 2 h 3b 55
60 ꢀC, 2 h 3b 62
60 ꢀC, 1 h 3b 74
TfOH
CH2Cl2
OTf
Ph
O
ð1Þ
2
3
80%
4c
5
AuCl-PPh3 60 ꢀC, 2 h 3b 52
Ph
1a
6
AuCl
AuCl
AuCl
40 ꢀC, 7 h 3b 81
40 ꢀC, 8 h 3a 72
40 ꢀC, 9 h 3c 62
40 ꢀC, 4 h 3d 87
40 ꢀC, 9 h 3e 73
40 ꢀC, 9 h 3f 65
6
Ph
7
1c p-CF3C6H4
1d p-MeC6H4
1e Ph
Ph
8
C3H7 AuCl
tBu
AuCl
O2C
N2
OTf
+
9
O
(CH2Cl)2
10
a
1f 2-Benzofuranyl C3H7 AuCl
ð2Þ
Ph
O
Ph
3a
All reactions were carried out with 1 (1 equiv) and 2a (1.8 equiv) in the
6
2a
presence of gold catalyst (10 mol %) in (CH2Cl)2.
b
40 ºC, 8 h
80 ºC, 3 h
36%
62%
Isolated yield.
Starting material 1b was recovered in 25% yield.
c

K. Sato et al. / Tetrahedron 64 (2008) 787e796
789
R
R
Introduction of alkenyl and alkynyl groups at C10-position
on the anthracene skeleton was also examined. Treatment of
a,b-unsaturated ketone derivative 1g with 2a in the presence
of AuCl catalyst under the standard condition resulted in the
formation of a styrenyl substituted anthracene product 3g in
50% yield (Eq. 3). The reactions of 1hej, bearing alkynyl
group at the carbonyl group, with 2a also proceeded smoothly
and alkynyl substituted anthracene products 3hej were
obtained in good yields, respectively (Eq. 4).
O
1
R'
3
AuCl
O
R'
R
O
O
R'
R
R'
7
ClAu
ClAu
11
Ph
Ph
AuCl
O2C
N2
(10 mol %)
+
ð3Þ
O
(CH2Cl)2
40 °C, 2 h
R
R
O
O
C3H7
O
C3H7
1g
2a
3g
50%
R'
R'
AuCl
AuCl
10
8
R
O2C
N2
R
AuCl
O2C
(10 mol %)
9
2a
+
O
(CH2Cl)2
40 ºC, 2~4 h
N2
Scheme 2. A plausible mechanism of the gold-catalyzed benzannulation.
ð4Þ
C3H7
O
C3H7
73 %
constructing molecular devices and synthetic molecular ma-
chines.18 It is well known that DielseAlder reaction between
anthracene and benzyne is an established protocol for prepara-
tion of triptycene.19 However, in the present benzannulation,
such triptycene products were not obtained at all even though
excess amount of benzyne precursor 2a was used toward
ortho-alkynylphenyl ketone 1. On the other hand, the reaction
of 9-acetylanthracene with benzyne has been reported to give
9-acetyltriptycene in moderate yield.20 These results suggest
that the substituent at C10-position on the anthracene skeleton
hampers the approach of benzyne due to its steric hindrance. It
occurred to us that the reaction of ortho-alkynylbenzaldehyde
1 would produce triptycene since the anthracene product
derived from such substrate has no substituents at the C10-
position. Then, we prepared 1k and examined the reaction with
3.5 equiv of benzyne precursor 2a. As we anticipated, the
reaction proceeded at 80 ꢀC for 0.5 h and 9-triptycyl ketone
4a was obtained in 51% yield as a sole product. Dimethoxy-
substituted triptycene 4b was also obtained from 1l in 35%
yield by the present one-pot procedure.
1h-j
2a
3h: R = Ph
t
3i: R = Bu
73 %
i
3j: R = Si(Pr)3 77 %
2.3. Reaction mechanism of benzannulation
A plausible mechanism for the present benzannulation is
shown in Scheme 2. The coordination of the triple bond of 1
to AuCl enhances the electrophilicity of alkyne, and the sub-
sequent nucleophilic attack (as shown in 7) of the carbonyl ox-
ygen to the electron-deficient alkyne would form the ate
complex 8. The reverse electron demand-type DielseAlder re-
action between 8 and benzyne 9, derived from 2a, would gen-
erate the intermediate 11 through 10. The subsequent bond
rearrangement, as shown in 11, would afford the anthranyl ke-
tones 3 and regenerate AuCl.11 Due to the instability of benz-
yne 9, it is necessary that 9 should be trapped by the
intermediate 8 as soon as it is generated from the precursor
2a. Probably, the generation speed of 8 is faster than that of
benzyne 9 under the optimized reaction condition, which
could keep the catalytic cycle effective.
CHO
R
R
O2C
N2
AuCl (10 mol %)
(CH2Cl)2
80 °C, 0.5 h
+
2.4. Triptycene synthesis
C3H7
2a
1k: R = H
1l: R = MeO
Triptycene12 and its derivatives form an interesting class of
compounds due to their three-dimensional rigid frameworks.
They have been found to have unique electrochemical and
photochemical properties,13 interesting reactivities,14 potential
pharmaceutical properties,15 and attractive applications in su-
pramolecular chemistry16 and materials science.17 Moreover,
they have also been shown to be useful building blocks in
R
ð5Þ
R
O
C3H7
4a: R = H
4b: R = MeO
51%
35%

790
K. Sato et al. / Tetrahedron 64 (2008) 787e796
2.5. Phthalazine derivatives synthesis
Nitrogen-containing heterocyclic compounds are wide-
spread in nature, and their applications to biologically active
pharmaceuticals, agrochemicals, and functional materials are
becoming more and more important.21 The development of
new efficient methods to synthesize N-heterocycles with struc-
tural diversity is of major interest to modern synthetic organic
chemists.22 While exploring the scope of the benzannulation
with benzyne, we examined the AuCl-catalyzed reaction of
1m with 2a in 1,4-dioxane at rt. To our surprise, the reaction
gave a small amount of phthalazine derivative 5a together
with anthryl ketone 3k. It is clear that 5a was produced from
1m and 2a directly without the generation of benzyne via the
thermal decomposition of 2a. Only a few papers have been re-
ported on the synthetic utility of 2a, excluding the usefulness as
a benzyne precursor.23 Therefore, this result prompted us to in-
vestigate the present cycloaddition reaction as a novel synthetic
approach to phthalazine derivatives and the results are summa-
rized in Table 2. When the reaction was carried out with
1.1 equiv of 2a in the presence of 5 mol % of AuCl in 1,4-
dioxane at rt, the reaction proceeded for 24 h and 5a was
obtained in 17% yield. Besides 5a, anthryl ketone 3k and
hydrated product 12 were obtained in 11 and 17% yields, re-
spectively (entry 1). The chemical yield of 5a was increased
up to 40% with AuCl3 catalyst instead of AuCl (entry 2). How-
ever, other catalysts, such as AuBr3, Cu(OTf)2, PtCl2, and
Pd(OAc)2, were less effective (entries 3e6).
Figure 1. X-ray structure of 5b.
catalyst proceeded at rt for 2 days and benzo[g]phthalazine de-
rivative 5b was obtained in 88% yield (Eq. 6). Other aryne
precursors 2b,c were also suitable for the current cycloaddi-
tion reaction and the corresponding products 5c,d were
obtained in 77 and 91% yields, respectively (Eqs. 7 and 8).
The structure of 5b was unambiguously confirmed by X-ray
analysis (Fig. 1).
Ph
O2C
AuCl (10 mol %)
O
+
Interestingly, the chemical yield of phthalazine derivative
was increased dramatically when the reaction was carried
out with ortho-alkynylnaphthyl ketone 1n instead of 1m.
Indeed, the reaction of 1n with 2a in the presence of AuCl
1,4-dioxane
rt, 48 h
N2
C3H7
88%
O
1n
2a
ð6Þ
O
Ph
Table 2
The gold-catalyzed synthesis of phthalazine derivativesa
N
N
Ph
O2C
O
C3H7
5b
cat. (5 mol %)
O
+
1,4-dioxane
rt
N2
C3H7
O
1m
2a
O
AuCl
Ph
O
O2C
N2
O
O
(5 mol %)
+
1n
N
N
Ph
Ph
1,4-dioxane
rt, 10 h
Ph
O
O
+
+
N
N
77%
C3H7
2b
5c
O
C3H7
O
C3H7
ð7Þ
ð8Þ
C3H7
5a
3k
12
O
Entry
Cat.
Time (h)
Yield %b
O
O2C
N2
Ph
O
5a
3k
12
1m
AuCl (5 mol %)
1n
+
N
N
1
2
3
4
5
6
a
AuCl
AuCl3
AuBr3
24
12
24
12
24
12
17
40
24
0
11
0
17
22
29
0
12
0
1,4-dioxane
rt, 10 h
OMe
OMe
91%
4
0
C3H7
2c
5d
Cu(OTf)2
PtCl2
Pd(OAc)2
0
62
50
6
0
23
7
15
5
2.6. Reaction mechanism of cycloaddition
6
All reactions were carried out with 1m (1 equiv) and 2a (1.1 equiv) in the
A plausible mechanism for the current transformation is
shown in Scheme 3. After the formation of the key
presence of catalyst (5 mol %) in 1,4-dioxane at rt.
b
Determined by 1H NMR spectra using p-xylene as an internal standard.

K. Sato et al. / Tetrahedron 64 (2008) 787e796
791
intermediate 8, the carboxylate moiety of 2 attacks 8 to give
4. Experimental
13. The subsequent intramolecular addition of the enol moi-
ety of 13 to the diazonium group, followed by cleavage of
the carboneenol oxygen bond, as shown in 13, affords
10-membered cyclized intermediate 14. The attack of nitrogen
to the electron-deficient benzyl carbon results in a second
cyclization to afford the phthalazine 5 and regenerate AuCl.
Probably, the generation of a benzyne from 2 is sluggish at
rt in 1,4-dioxane and the electrophilicity of the intermediate
8 is high enough to react with 2 under the optimized condi-
tions. Obviously, compared to benzo[c]pyrylium intermediate
8 derived from 1m, benzo[g]isochromenium intermediate
derived from 1n would be more stable due to its superior
resonance effect. This might be the reason why phthalazine
derivatives 5bed were obtained in higher yields than that
of 5a.
4.1. General
NMR spectra were measured at 400 MHz for 1H and
100 MHz for 13C by JEOL JNM-AL 400 spectrometer. Chemi-
cal shifts of 1H NMR were expressed in parts per million down-
field from tetramethylsilane with reference to internal residual
CHCl3 (d¼7.26) in CDCl3. Chemical shifts of 13C NMR were
expressed in parts per million downfield from CDCl3 as an in-
ternal standard (d¼77.0) in CDCl3. High-resolution mass spec-
tra (HRMS) were performed on BRUKER DALTONICS
APEX III spectrometer. For thin layer chromatography (TLC)
analysis throughout this work, Merck precoated TLC plates
(Kieselgel 60 F254, 0.2 mm) were used. The products were pu-
rified by flash column chromatography on silica gel 60N
(KANTO, 40e50 mm). All manipulations were carried out un-
der argon atmosphere using standard Schlenk techniques.
O
R
O
Ph
4.2. Typical procedure for preparation of anthryl ketone 3
O
N
1
N
The preparation of 3b is representative. To a mixture of
AuCl (12 mg, 10 mol %) and 1b (148 mg, 0.5 mmol) in 1,2-di-
chloroethane (3.5 mL) was added a creamy white solid of benz-
enediazonium 2-carboxylate 2a (133 mg, 0.9 mmol) at rt under
Ar atmosphere. After the reaction mixture was stirred for 7 h at
40 ꢀC, the resulting solution was filtered through a short pad of
silica gel. The filtrate was evaporated under reduced pressure to
give the crude product, which was purified by silica gel column
chromatography with hexane/ether as eluent to give 3b
(151 mg, 0.405 mmol) in 81% yield as a white solid.
R'
AuCl
O
C3H7
5
R
O
O
O
R
N
N
R'
7
ClAu
O
AuCl
R'
14
O
R
O
O
N
4.3. Typical procedure for preparation of triptycyl
ketone 4
R
O
O
N
O
N
R'
2
N
ClAu
The preparation of 4a is representative. To a mixture of
AuCl (7.0 mg, 10 mol %) and 1k (51.6 mg, 0.30 mmol) in
1,2-dichloroethane (2.0 mL) was added a creamy white solid
of benzenediazonium 2-carboxylate 2a (155 mg, 1.05 mmol)
at rt under Ar atmosphere. The mixture was warmed to 80 ꢀC
and stirred for 0.5 h. After cooling, the resulting solution was
filtered through a short pad of silica gel. The filtrate was evap-
orated under reduced pressure to give the crude product, which
was recrystallized from hexane/ether/CH2Cl2 to give 4a
(49.6 mg, 0.15 mmol) in 51% yield as a white solid.
8
R'
ClAu
13
Scheme 3. A plausible mechanism of the cycloaddition for the synthesis of
phthalazine derivatives.
3. Conclusion
We are now in a position to synthesize functionalized an-
thracene derivatives from ortho-alkynylphenyl ketones 1 and
benzenediazonium 2-carboxylate 2 in good to high yields.
The reaction most probably proceeds through the inverse
electron demand-type DielseAlder reaction between the in-
termediate 8 and benzyne 9. The protocol can be applied to
the synthesis of triptycyl ketones 4 by using ortho-alkynyl-
benzaldehyde. The direct cycloaddition between 1 and 2 pro-
ceeds under lower temperatures without the generation of
benzyne, leading to phthalazine derivatives 5. Further studies
to elucidate the precise mechanism of these reactions and to
extend the scope of synthetic utility are in progress in our
laboratory.
4.4. Typical procedure for preparation of phthalazine
derivatives 5
The preparation of 5b is representative. To a mixture of
AuCl (7.0 mg, 10 mol %) and 1n (107 mg, 0.36 mmol) in 1,4-
dioxane (2.1 mL) was added a creamy white solid of benzene-
diazonium 2-carboxylate 2a (44 mg, 0.30 mmol) at rt under Ar
atmosphere. After the reaction mixture was stirred for 48 h at
rt, the resulting solution was filtered through a short pad of sil-
ica gel. The filtrate was evaporated under reduced pressure to
give the crude product, which was recrystallized from hexane/

792
K. Sato et al. / Tetrahedron 64 (2008) 787e796
ether/CH2Cl2 to give 5b (118 mg, 0.26 mmol) in 88% yield as
a light yellow solid.
7.47e7.36 (m, 6H), 0.92 (s, 9H). 13C NMR (CDCl3,
100 MHz) d 197.4, 141.7, 137.4, 132.8, 132.1, 130.1, 129.9,
128.2, 128.1, 127.5, 122.3, 104.8, 77.2, 30.3, 27.8. IR
4.5. Characterization data
(KBr): 2964, 2239, 1560, 1472, 1362, 1028, 806, 440 cmꢁ1
.
MS (EI) m/z 262 (Mþ, 15). HRMS calcd for C19H18ONa
([MþNa]þ): 285.1250, found: 285.1250. Mp¼64e66 ꢀC.
4.5.1. Phenyl(2-(2-phenylethynyl)phenyl)methanone (1a)
1
White solid; H NMR (CDCl3, 400 MHz) d 7.88 (m, 2H),
7.63e7.43 (m, 7H), 7.24e7.18 (m, 3H), 7.04 (m, 2H). 13C
NMR (CDCl3, 100 MHz) d 196.9, 141.5, 137.3, 133.0,
132.5, 131.3, 130.21, 130.20, 128.6, 128.3, 128.1, 128.0,
122.5, 121.8, 95.1, 87.4. IR (KBr): 3063, 2216, 1668, 1595,
1315, 843, 694, 638 cmꢁ1. MS (EI) m/z 282 (Mþ, 88).
HRMS calcd for C21H14ONa ([MþNa]þ): 305.0937, found:
305.0937. Mp¼49e50 ꢀC.
4.5.6. Benzofuran-2-yl(2-(pent-1-ynyl)phenyl)-
methanone (1f)
Yellow oil; 1H NMR (CDCl3, 400 MHz) d 7.68 (ddd,
J¼0.8, 1.2, 7.6 Hz, 1H), 7.62 (ddd, J¼0.7, 1.0, 8.8 Hz, 1H),
7.55 (ddd, J¼1.2, 7.6, 8.8 Hz, 2H), 7.50 (dd, J¼1.2, 7.3 Hz,
1H), 7.46 (dd, J¼1.4, 7.6 Hz, 1H), 7.39 (ddd, J¼1.4, 7.3,
7.6 Hz, 1H), 7.34 (d, J¼1.0 Hz, 1H), 7.31 (ddd, J¼1.0, 7.3,
7.3 Hz, 1H), 2.16 (t, J¼6.8 Hz, 2H), 1.30 (tt, J¼6.8, 7.6 Hz,
2H), 0.78 (t, J¼7.6 Hz, 3H). 13C NMR (CDCl3, 100 MHz)
d 185.5, 156.0, 152.3, 140.3, 132.9, 130.4, 128.3, 127.9,
127.1, 127.0, 123.7, 123.2, 122.7, 117.0, 112.4, 96.0, 78.2,
21.7, 21.3, 13.2. IR (KBr): 2963, 2233, 1614, 1553, 1300,
1128, 974, 754 cmꢁ1. MS (EI) m/z 288 (Mþ, 9). HRMS calcd
for C20H16O2Na ([MþNa]þ): 311.1043, found: 311.1044.
4.5.2. (2-(2-Phenylethynyl)phenyl)( p-tolyl)methanone (1b)
White solid; 1H NMR (CDCl3, 400 MHz) d 7.78 (d,
J¼8.0 Hz, 2H), 7.61 (ddd, J¼0.7, 1.2, 7.8 Hz, 1H), 7.52e
7.42 (m, 3H), 7.28e7.18 (m, 5H), 7.06 (ddd, J¼2.4, 3.9,
8.3 Hz, 2H), 2.42 (s, 3H). 13C NMR (CDCl3, 100 MHz)
d 196.5, 143.9, 141.8, 134.8, 132.4, 131.3, 130.4, 130.0,
129.0, 128.4, 128.3, 128.0, 128.0, 122.7, 121.7, 94.8, 87.5,
21.8. IR (KBr): 1948, 1665, 1491, 930, 835, 777, 608,
515 cmꢁ1. MS (EI) m/z 296 (Mþ, 94). HRMS calcd for
C22H16ONa ([MþNa]þ): 319.1093, found: 319.1092.
Mp¼89e90 ꢀC.
4.5.7. (E )-1-(2-(Pent-1-ynyl)phenyl)-3-phenylprop-
2-en-1-one (1g)
1
Light yellow oil; H NMR (CDCl3, 400 MHz) d 7.59 (m,
4H), 7.51 (dd, J¼1.1, 7.8 Hz, 1H), 7.40 (m, 6H), 2.32 (t,
J¼7.1 Hz, 2H), 1.47 (qt, J¼7.1, 7.3 Hz, 2H), 0.92 (t,
J¼7.3 Hz, 3H). 13C NMR (CDCl3, 100 MHz) d 194.2, 144.0,
142.0, 134.9, 133.1, 130.4, 130.3, 128.8, 128.3, 128.2, 127.5,
126.0, 122.3, 96.9, 79.2, 22.0, 21.6, 13.5. IR (neat): 2963,
2232, 1607, 1576, 1448, 1333, 1207, 758 cmꢁ1. MS (EI) m/z
274 (Mþ, 2). HRMS calcd for C20H18ONa ([MþNa]þ):
297.1250, found: 297.1251. Anal. Calcd for C20H18O: C,
87.56; H, 6.61. Found: C, 87.55; H, 6.48.
4.5.3. (2-(2-Phenylethynyl)phenyl)(4-(trifluoromethyl)-
phenyl)methanone (1c)
White solid; 1H NMR (CDCl3, 400 MHz) d 7.98 (d,
J¼8.0 Hz, 2H), 7.73 (d, J¼8.0 Hz, 2H), 7.63 (ddd, J¼0.7,
1.2, 7.6 Hz, 1H), 7.59 (ddd, J¼0.7, 1.2, 7.6 Hz, 1H), 7.55
(ddd, J¼1.2, 7.3, 7.6 Hz, 1H), 7.48 (ddd, J¼1.2, 7.3, 7.6 Hz,
1H), 7.28e7.18 (m, 3H), 6.97 (ddd, J¼1.2, 1.5, 6.8 Hz, 2H).
13C NMR (CDCl3, 100 MHz) d 195.8, 140.3, 134.3, 134.0,
132.7, 131.2, 131.0, 130.3, 129.0, 128.6, 128.4, 128.1,
125.3, 124.9, 122.2, 122.0, 96.0, 87.3. IR (KBr): 3072,
1672, 1410, 1331, 1067, 932, 756, 691 cmꢁ1. MS (EI) m/z
350 (Mþ, 100). HRMS calcd for C22H13F3ONa ([MþNa]þ):
373.0811, found: 373.0809. Mp¼62e63 ꢀC.
4.5.8. 1-(2-(Pent-1-ynyl)phenyl)-3-phenylprop-
2-yn-1-one (1h)
1
Yellow oil; H NMR (CDCl3, 400 MHz) d 8.10 (dd, J¼1.2,
7.8 Hz, 1H), 7.65 (m, 2H), 7.54 (dd, J¼1.2, 7.8 Hz, 1H), 7.50e
7.45 (m, 2H), 7.42e7.37 (m, 3H), 2.42 (t, J¼7.1 Hz, 2H), 1.63
(tt, J¼7.1, 7.3 Hz, 2H), 1.05 (t, J¼7.3 Hz, 3H). 13C NMR
(CDCl3, 100 MHz) d 177.7, 138.5, 134.5, 133.0, 132.2, 131.1,
130.5, 128.5, 127.1, 123.8, 120.4, 97.3, 92.9, 88.2, 79.2, 22.1,
22.0, 13.7. IR (neat): 2963, 2197, 1647, 1560, 1489, 1204,
995, 756 cmꢁ1. MS (EI) m/z 272 (Mþ, 48). HRMS calcd for
C20H16ONa ([MþNa]þ): 295.1093, found: 295.1092.
4.5.4. (2-(Pent-1-ynyl)phenyl)( p-tolyl)methanone (1d)
Light yellow oil; 1H NMR (CDCl3, 400 MHz) d 7.71 (ddd,
J¼1.0, 1.2, 8.1 Hz, 2H), 7.47 (ddd, J¼1.0, 1.2, 7.8 Hz, 1H),
7.43e7.33 (m, 3H), 7.23 (d, J¼8.1 Hz, 2H), 2.42 (s, 3H),
2.11 (t, J¼6.8 Hz, 2H), 1.27 (tt, J¼6.8, 7.3 Hz, 2H), 0.78 (t,
J¼7.3 Hz, 3H). 13C NMR (CDCl3, 100 MHz) d 196.7,
143.7, 141.9, 134.6, 132.4, 130.2, 129.6, 128.8, 127.7,
127.1, 122.2, 96.0, 78.6, 21.7 (ꢂ2), 21.3, 13.3. IR (neat):
2963, 2235, 1666, 1607, 1312, 1151, 928, 758 cmꢁ1. MS
(EI) m/z 262 (Mþ, 2). HRMS calcd for C19H18ONa
([MþNa]þ): 285.1250, found: 285.1250.
4.5.9. 4,4-Dimethyl-1-(2-(pent-1-ynyl)phenyl)-
pent-2-yn-1-one (1i)
Yellow oil; 1H NMR (CDCl3, 400 MHz) d 8.01 (d,
J¼7.8 Hz, 1H), 7.50 (d, J¼7.3 Hz, 1H), 7.44 (dd, J¼7.3,
7.3 Hz, 1H), 7.35 (dd, J¼7.3, 7.8 Hz, 1H), 2.45 (t,
J¼7.1 Hz, 2H), 1.68 (tt, J¼7.1, 7.3 Hz, 2H), 1.35 (s, 9H),
1.09 (t, J¼7.3 Hz, 3H). 13C NMR (CDCl3, 100 MHz)
d 177.9, 138.5, 134.4, 131.8, 131.4, 126.9, 123.5, 103.3,
96.5, 79.4, 79.2, 30.2, 28.0, 22.1, 22.0, 13.7. IR (neat):
2970, 2210, 1653, 1562, 1477, 1225, 756, 691 cmꢁ1. MS
4.5.5. (2-(3,3-Dimethylbut-1-ynyl)phenyl)(phenyl)-
methanone (1e)
White solid; 1H NMR (CDCl3, 400 MHz) d 7.82 (ddd,
J¼0.7, 1.4, 7.8 Hz, 2H), 7.56 (ddd, J¼7.3, 7.6 Hz, 1H),

K. Sato et al. / Tetrahedron 64 (2008) 787e796
793
(EI) m/z 252 (Mþ, 86). HRMS calcd for C18H20ONa
([MþNa]þ): 275.1406, found: 275.1407.
127.0, 119.4, 95.8, 79.0, 21.8, 21.4, 13.5. IR (neat): 2963,
2232, 1668, 1597, 1448, 1217, 893, 750 cmꢁ1. MS (EI) m/z
298 (Mþ, 8). Anal. Calcd for C22H18O: C, 88.56; H, 6.08.
Found: C, 88.47; H, 6.04.
4.5.10. 1-(2-(Pent-1-ynyl)phenyl)-3-(triisopropylsilyl)-
prop-2-yn-1-one (1j)
Orange oil; 1H NMR (CDCl3, 400 MHz) d 8.17 (dd, J¼1.4,
7.8 Hz, 1H), 7.52 (dd, J¼1.4, 7.8 Hz, 1H), 7.46 (ddd, J¼1.4,
7.6, 7.8 Hz, 1H), 7.36 (ddd, J¼1.4, 7.6, 7.8 Hz, 1H), 2.46 (t,
J¼7.1 Hz, 2H), 1.68 (tt, J¼7.1, 7.3 Hz, 2H), 1.16 (m, 3H),
1.15 (d, J¼4.9 Hz, 18H), 1.09 (t, J¼7.3 Hz, 3H). 13C NMR
(CDCl3, 100 MHz) d 176.7, 137.8, 134.7, 132.2, 132.1,
127.0, 123.7, 103.8, 97.2, 96.8, 79.5, 22.1, 22.0, 18.6, 13.7,
11.2. IR (neat): 2866, 2233, 2149, 1653, 1560, 1229, 1013,
883, 754 cmꢁ1. MS (EI) m/z 309 (MþꢁC3H7, 100). HRMS
calcd for C23H32OSiNa ([MþNa]þ): 375.2115, found:
375.2115.
4.5.15. Phenyl(9-phenylanthracen-10-yl)methanone (3a)
1
Light yellow solid; H NMR (CDCl3, 400 MHz) d 7.92 (d,
J¼7.7 Hz, 2H), 7.76 (dd, J¼1.2, 8.6 Hz, 2H), 7.71 (dd, J¼1.0,
8.3 Hz, 2H), 7.64e7.55 (m, 4H), 7.47 (m, 4H), 7.38 (ddd,
J¼1.5, 6.5, 7.7 Hz, 2H), 7.34 (ddd, J¼1.4, 6.5, 7.7 Hz, 2H).
13C NMR (CDCl3, 100 MHz) d 200.3, 138.9, 138.3, 138.1,
134.1, 133.9, 131.0, 130.0, 129.6, 128.8, 128.4, 128.2,
128.1, 127.6, 127.3, 126.1, 125.3. IR (KBr): 1665, 1518,
1389, 1227, 1070, 851, 710, 644 cmꢁ1. MS (EI) m/z 358
(Mþ, 100). HRMS calcd for C27H18ONa ([MþNa]þ):
381.1250, found: 381.1249. Mp¼215e219 ꢀC.
4.5.11. 2-(Pent-1-ynyl)benzaldehyde (1k)
4.5.16. Phenyl(9-p-tolylanthracen-10-yl)methanone (3b)
Yellow solid; 1H NMR (CDCl3, 400 MHz) d 7.90 (d,
J¼7.1 Hz, 2H), 7.75 (m, 4H), 7.60 (ddd, J¼1.2, 1.2, 7.3 Hz,
1H), 7.46e7.31 (m, 10H), 2.55 (s, 3H). 13C NMR (CDCl3,
100 MHz) d 200.4, 139.1, 138.1, 137.3, 135.2, 133.9, 130.9,
130.0, 129.7, 129.1, 128.8, 128.2, 127.4, 126.1, 125.3,
125.2, 21.5. IR (KBr): 3912, 1665, 1443, 1312, 1225, 930,
820, 729 cmꢁ1. MS (EI) m/z 372 (Mþ, 100). HRMS calcd
for C28H20ONa ([MþNa]þ): 395.1406, found: 395.1406.
Mp¼258e262 ꢀC.
1
Light yellow oil; H NMR (CDCl3, 400 MHz) d 10.54 (s,
1H), 7.89 (ddd, J¼1.0, 1.0, 7.8 Hz, 1H), 7.51 (m, 2H), 7.38
(m, 1H), 2.47 (t, J¼7.1 Hz, 2H), 1.68 (qt, J¼7.1, 7.3 Hz,
2H), 1.08 (t, J¼7.3 Hz, 3H). 13C NMR (CDCl3, 100 MHz)
d 192.1, 135.9, 133.6, 133.2, 127.9, 127.8, 126.8, 98.0, 76.5,
22.1, 21.6, 13.7. IR (neat): 3065, 3032, 2905, 2745, 2233,
1653, 1429, 1339, 1296, 1159, 637 cmꢁ1. MS (EI) m/z 172
(Mþ, 2). HRMS calcd for C12H12ONa ([MþNa]þ):
195.0780, found: 195.0779.
4.5.12. 4,5-Dimethoxy-2-(pent-1-ynyl)benzaldehyde (1l)
4.5.17. Phenyl(9-(4-(trifluoromethyl)phenyl)anthracen-10-yl)
methanone (3c)
1
Light yellow oil; H NMR (CDCl3, 400 MHz) d 10.38 (s,
1H), 7.36 (s, 1H), 6.92 (s, 1H), 3.95 (s, 3H), 3.93 (s, 3H),
2.45 (t, J¼6.9 Hz, 2H), 1.67 (tq, J¼6.9, 6.9 Hz, 2H), 1.07 (t,
J¼6.9 Hz, 3H). 13C NMR (CDCl3, 100 MHz) d 190.8,
153.5, 149.1, 130.1, 122.7, 114.4, 107.9, 96.4, 76.2, 56.2,
56.1, 22.1, 21.6, 13.7. IR (neat): 2963, 2936, 2835, 1682,
1593, 1506, 1352, 1283, 1221, 1124, 1009 cmꢁ1. MS (EI)
m/z 232 (Mþ, 11). Anal. Calcd for C14H16O3: C, 72.39; H,
6.94. Found: C, 72.19; H, 6.90.
Light yellow solid; 1H NMR (CDCl3, 400 MHz) d 7.90 (m,
4H), 7.78 (m, 2H), 7.61 (m, 5H), 7.46 (dd, J¼7.3, 8.0 Hz, 2H),
7.40 (ddd, J¼1.7, 6.6, 6.6 Hz, 2H), 7.37 (ddd, J¼1.7, 6.6,
6.6 Hz, 2H). 13C NMR (CDCl3, 100 MHz) d 200.1, 142.4,
138.0, 137.0, 134.8, 134.0, 131.5, 130.2, 130.0, 129.9,
129.4, 128.9, 128.1, 126.7, 126.3, 125.8, 125.5, 122.9. IR
(KBr): 3062, 1668, 1325, 1227, 930, 708, 685, 448 cmꢁ1
.
MS (EI) m/z 426 (Mþ, 100). HRMS calcd for C28H17F3ONa
([MþNa]þ): 449.1124, found: 449.1125. Mp¼329e331 ꢀC.
4.5.13. (2-(Pent-1-ynyl)phenyl)(phenyl)methanone (1m)
1
Light yellow oil; H NMR (CDCl3, 400 MHz) d 7.82 (m,
4.5.18. 1-(9-p-Tolylanthracen-10-yl)butan-1-one (3d)
1
Light yellow solid; H NMR (CDCl3, 400 MHz) d 7.77 (d,
2H), 7.56 (m, 1H), 7.49e7.34 (m, 6H), 2.08 (t, J¼7.3 Hz,
2H), 1.26 (tq, J¼7.3, 7.3 Hz, 2H), 0.77 (t, J¼7.3 Hz, 3H).
13C NMR (CDCl3, 100 MHz) d 197.2, 141.6, 137.2, 132.9,
132.5, 130.0, 129.9, 128.1, 128.0, 127.2, 122.4, 96.4, 78.7,
21.7, 21.3, 13.4. IR (neat): 2963, 2235, 1668, 1597, 1450,
1317, 1288, 928 cmꢁ1. MS (EI) m/z 248 (Mþ, 2). HRMS calcd
for C18H16ONa ([MþNa]þ): 271.1093, found: 271.1093.
J¼8.8 Hz, 2H), 7.66 (d, J¼8.8 Hz, 2H), 7.44 (dd, J¼7.1,
8.0 Hz, 2H), 7.36e7.21 (m, 6H), 3.07 (t, J¼7.3 Hz, 2H),
2.49 (s, 3H), 1.92 (tt, J¼7.3, 7.3 Hz, 2H), 1.08 (t, J¼7.3 Hz,
3H). 13C NMR (CDCl3, 100 MHz) d 210.5, 138.8, 137.2,
136.7, 135.1, 130.8, 129.7, 129.0, 127.5, 126.5, 126.2,
125.1, 124.3, 48.5, 21.4, 17.4, 14.0. IR (KBr): 2870, 1695,
1512, 1159, 808, 766, 665, 611 cmꢁ1. MS (EI) m/z 338
(Mþ, 35). HRMS calcd for C25H22ONa ([MþNa]þ):
361.1563, found: 361.1562. Mp¼141e144 ꢀC.
4.5.14. (3-(Pent-1-ynyl)naphthalen-2-yl)(phenyl)-
methanone (1n)
1
Light yellow oil; H NMR (CDCl3, 400 MHz) d 7.99 (s,
1H), 7.92 (s, 1H), 7.84 (m, 4H), 7.59e7.52 (m, 3H), 7.45
(dd, J¼7.6, 7.6 Hz, 2H), 2.14 (t, J¼7.1 Hz, 2H), 1.31 (tq,
J¼7.3, 7.1 Hz, 2H), 0.82 (t, J¼7.3 Hz, 3H). 13C NMR
(CDCl3, 100 MHz) d 196.9, 138.7, 137.5, 135.0, 133.5,
132.8, 132.3, 131.4, 130.1, 128.4, 128.1, 127.7, 127.3,
4.5.19. 2,2-Dimethyl-1-(9-phenylanthracen-10-yl)-
propan-1-one (3e)
1
Light yellow solid; H NMR (CDCl3, 400 MHz) d 7.79 (d,
J¼8.8 Hz, 2H), 7.69 (d, J¼8.8 Hz, 2H), 7.63e7.54 (m, 3H),
7.50e7.46 (m, 3H), 7.40e7.33 (m, 3H), 1.40 (s, 9H). 13C

794
K. Sato et al. / Tetrahedron 64 (2008) 787e796
NMR (CDCl3, 100 MHz) d 218.5, 138.3, 138.1, 136.5, 131.2,
130.8, 129.5, 128.3, 128.3, 127.6, 127.3, 126.9, 125.7, 125.5,
125.2, 46.3, 28.3. IR (KBr): 2967, 1686, 1474, 1443, 1084,
1028, 932, 700, 611 cmꢁ1. MS (EI) m/z 338 (Mþ, 9). HRMS
calcd for C25H22ONa ([MþNa]þ): 361.1563, found:
361.1564. Mp¼201e205 ꢀC.
d 210.0, 136.5, 131.7, 127.4, 126.6, 126.4, 126.1, 124.6,
120.1, 111.5, 75.5, 48.3, 31.3, 28.9, 17.3, 13.9. IR (KBr):
2964, 2208, 1701, 1560, 1396, 1132, 932, 806, 768 cmꢁ1
.
MS (EI) m/z 328 (Mþ, 41). HRMS calcd for C24H24ONa
([MþNa]þ): 351.1719, found: 351.1720. Mp¼134e137 ꢀC.
4.5.24. 1-(9-(2-(Triisopropylsilyl)ethynyl)anthracen-10-yl)-
butan-1-one (3j)
4.5.20. 1-(9-(Benzofuran-2-yl)anthracen-10-yl)-
butan-1-one (3f)
Yellow oil; 1H NMR (CDCl3, 400 MHz) d 8.69 (dd, J¼1.0,
8.6 Hz, 2H), 7.80 (dd, J¼1.0, 8.6 Hz, 2H), 7.62 (ddd, J¼1.0,
6.6, 8.6 Hz, 2H), 7.54 (ddd, J¼1.0, 6.6, 8.6 Hz, 2H), 3.03 (t,
J¼7.3 Hz, 2H), 1.92 (tt, J¼7.3, 7.6 Hz, 2H), 1.30 (m, 3H),
1.29 (d, J¼5.1 Hz, 18H), 1.10 (t, J¼7.6 Hz, 3H). 13C NMR
(CDCl3, 100 MHz) d 209.7, 137.5, 132.3, 127.4, 126.7,
126.6, 126.4, 124.7, 119.3, 104.2, 102.8, 48.4, 18.9, 17.3,
13.9, 11.6. IR (neat): 2864, 2141, 1701, 1462, 1412, 1134,
883, 766 cmꢁ1. MS (EI) m/z 428 (Mþ, 100). HRMS calcd
for C29H36OSiNa ([MþNa]þ): 451.2428, found: 451.2427.
1
Light yellow solid; H NMR (CDCl3, 400 MHz) d 8.00
(ddd, J¼1.0, 1.2, 8.8 Hz, 2H), 7.84 (ddd, J¼1.0, 1.2, 8.8 Hz,
2H), 7.77 (m, 1H), 7.63 (dd, J¼1.2, 8.8 Hz, 1H), 7.53 (ddd,
J¼1.2, 6.6, 8.8 Hz, 2H), 7.47 (ddd, J¼1.2, 6.6, 8.8 Hz, 2H),
7.42 (ddd, J¼1.2, 7.3, 7.3 Hz, 1H), 7.38 (ddd, J¼1.2, 7.3,
7.3 Hz, 1H), 7.08 (d, J¼1.2 Hz, 1H), 3.09 (t, J¼7.3 Hz, 2H),
1.96 (tt, J¼7.3, 7.6 Hz, 2H), 1.13 (t, J¼7.6 Hz, 3H). 13C
NMR (CDCl3, 100 MHz) d 209.9, 155.3, 152.2, 139.2,
130.9, 128.6, 128.5, 126.7, 126.5, 126.4, 126.3, 124.5,
123.0, 121.0, 111.4, 109.5, 109.5, 48.3, 17.3, 13.9. IR
(KBr): 2963, 1699, 1558, 1452, 1256, 1134, 810, 438 cmꢁ1
.
4.5.25. 1-(10-Phenylanthracen-9-yl)butan-1-one (3k)
White solid; 1H NMR (CDCl3, 400 MHz) d 7.84 (d,
J¼8.8 Hz, 2H), 7.68 (d, J¼8.8 Hz, 2H), 7.58 (m, 3H), 7.51
(m, 2H), 7.42 (m, 2H), 7.37 (m, 2H), 3.17 (t, J¼7.6 Hz,
2H), 1.98 (qt, J¼7.3, 7.6 Hz, 2H), 1.13 (t, J¼7.3 Hz, 3H).
13C NMR (CDCl3, 100 MHz) d 210.6, 138.6, 138.2, 136.8,
131.0, 129.6, 128.3, 127.6, 127.4, 126.4, 126.2, 125.5,
124.3, 48.5, 17.4, 14.0. IR (neat): 2966, 1697, 1443, 1161,
1123, 1026, 706, 610 cmꢁ1. MS (EI) m/z 324 (Mþ, 33).
HRMS calcd for C24H20ONa ([MþNa]þ): 347.1406, found:
347.1407. Mp¼118.5 ꢀC.
MS (EI) m/z 364 (Mþ, 46). HRMS calcd for C26H20O2 Na
([MþNa]þ): 387.1356, found: 387.1357. Mp¼130e133 ꢀC.
4.5.21. (E )-1-(10-Styrylanthracen-9-yl)butan-1-one (3g)
1
Light green solid; H NMR (CDCl3, 400 MHz) d 8.38 (d,
J¼8.5 Hz, 2H), 7.90 (d, J¼16.6 Hz, 1H), 7.80 (d, J¼8.1 Hz,
2H), 7.68 (d, J¼7.6 Hz, 2H), 7.49 (m, 6H), 7.37 (dd, J¼7.3,
7.3 Hz, 1H), 6.93 (d, J¼16.6 Hz, 1H), 3.07 (t, J¼7.3 Hz,
2H), 1.93 (qt, J¼7.3, 7.6 Hz, 2H), 1.08 (t, J¼7.6 Hz, 3H).
13C NMR (CDCl3, 100 MHz) d 210.6, 137.9, 136.9, 136.5,
134.5, 129.1, 128.8, 128.2, 126.62, 126.58, 126.3, 125.4,
124.7, 124.4, 48.5, 17.4, 14.0. IR (KBr): 2962, 2927, 1689,
1445, 1182, 1134, 966, 750, 692, 669 cmꢁ1. MS (EI) m/z
350 (Mþ, 70). HRMS calcd for C26H22ONa ([MþNa]þ):
373.1563, found: 373.1562. Mp¼154.5 ꢀC.
4.5.26. 1-(9-Triptycyl)butan-1-one (4a)
1
White solid; H NMR (CDCl3, 400 MHz) d 7.73 (m, 3H),
7.43 (m, 3H), 7.06 (m, 6H), 5.38 (s, 1H), 3.16 (m, 2H), 2.17
(tq, J¼7.2, 7.2 Hz, 2H), 1.18 (t, J¼7.2 Hz, 3H). 13C NMR
(CDCl3, 100 MHz) d 209.4, 146.3, 143.5, 125.4, 124.9,
123.8, 123.6, 66.4, 54.9, 46.8, 18.5, 14.3. IR (KBr): 2972,
2929, 1705, 1456, 1417, 1350, 1136, 1112, 1062, 966, 748,
633 cmꢁ1. MS (EI) m/z 324 (Mþ, 40). Anal. Calcd for
C24H20O: C, 88.85; H, 6.21. Found: C, 88.80; H, 6.24.
Mp¼189.5 ꢀC.
4.5.22. 1-(9-(2-Phenylethynyl)anthracen-10-yl)-
butan-1-one (3h)
Yellow solid; 1H NMR (CDCl3, 400 MHz) d 8.71 (d,
J¼8.5 Hz, 2H), 7.79 (ddd, J¼1.2, 7.6, 8.5 Hz, 4H), 7.62
(ddd, J¼1.2, 6.6, 6.8 Hz, 2H), 7.55 (ddd, J¼1.2, 6.6, 6.8 Hz,
2H), 7.49e7.43 (m, 3H), 3.05 (t, J¼7.3 Hz, 2H), 1.93 (tt,
J¼7.3, 7.3 Hz, 2H), 1.10 (t, J¼7.3 Hz, 3H). 13C NMR
(CDCl3, 100 Hz) d 209.9, 137.5, 131.9, 131.6, 128.7, 128.5,
127.4, 126.8, 126.5, 126.5, 124.8, 123.2, 119.1, 85.8, 77.2,
48.4, 17.3, 13.9. IR (KBr): 2873, 2365, 1695, 1493, 1441,
1132, 760, 692 cmꢁ1. MS (EI) m/z 348 (Mþ, 38). HRMS calcd
for C26H20ONa ([MþNa]þ): 371.1406, found: 371.1407.
Mp¼125e128 ꢀC.
4.5.27. 1-(2,3-Dimethoxy-9-triptycyl)butan-1-one (4b)
1
White solid; H NMR (CDCl3, 400 MHz) d 7.57 (m, 4H),
7.40 (m, 2H), 7.03 (m, 3H), 6.98 (s, 1H), 5.26 (s, 1H), 3.84
(s, 3H), 3.83 (s, 3H), 3.14 (m, 2H), 2.14 (tq, J¼7.2, 7.2 Hz,
2H), 1.15 (t, J¼7.2 Hz, 3H). 13C NMR (CDCl3, 100 MHz)
d 209.8, 146.6, 145.9, 145.4, 143.9, 139.7, 136.1, 125.4,
124.8, 123.4, 123.3, 109.3, 107.9, 66.1, 56.2, 56.0, 54.5,
46.8, 18.6, 14.3. IR (KBr): 2958, 2933, 1703, 1499, 1456,
1286, 1221, 1196, 1150, 1113, 1057, 880, 750, 621 cmꢁ1
.
MS (EI) m/z 384 (Mþ, 84). Anal. Calcd for C26H24O3: C,
81.22; H, 6.29. Found: C, 81.13; H, 6.23. Mp¼153.5 ꢀC.
4.5.23. 1-(9-(3,3-Dimethylbut-1-ynyl)anthracen-10-yl)-
butan-1-one (3i)
Yellow solid; 1H NMR (CDCl3, 400 MHz) d 8.61 (d,
J¼8.5 Hz, 2H), 7.79 (d, J¼8.5 Hz, 2H), 7.58 (dd, J¼7.3,
8.5 Hz, 2H), 7.52 (dd, J¼7.3, 8.5 Hz, 2H), 3.02 (t,
J¼7.6 Hz, 2H), 1.92 (tt, J¼7.3, 7.6 Hz, 2H), 1.57 (s, 9H),
1.09 (t, J¼7.3 Hz, 3H). 13C NMR (CDCl3, 100 MHz)
4.5.28. 1,2-Dihydrophthalazine derivative (5a)
Light yellow solid; 1H NMR (CDCl3, 400 MHz) d 8.52 (dd,
J¼0.7, 7.6 Hz, 1H), 7.94 (d, J¼7.6 Hz, 2H), 7.85 (dd, J¼0.7,

K. Sato et al. / Tetrahedron 64 (2008) 787e796
795
7.6 Hz, 1H), 7.66 (dt, J¼1.5, 7.3 Hz, 1H), 7.51 (dt, J¼1.1,
7.6 Hz, 1H), 7.44 (dt, J¼1.5, 7.2 Hz, 1H), 7.32 (m, 2H),
7.21 (m, 3H), 7.13 (t, J¼7.6 Hz, 1H), 3.23 (dt, J¼7.3,
17.1 Hz, 1H), 3.15 (dt, J¼7.3, 17.1 Hz, 1H), 1.86 (ddq,
J¼7.3, 7.3, 7.3 Hz, 2H), 1.10 (t, J¼7.3 Hz, 3H). 13C NMR
(CDCl3, 100 MHz) d 199.4, 160.7, 143.7, 141.9, 137.9,
135.9, 131.4, 131.3, 130.3, 129.3, 129.1, 129.0, 125.9,
125.4, 124.4, 123.7, 119.8, 116.2, 115.5, 90.3, 40.7, 18.3,
14.1. IR (KBr): 3960, 1740, 1682, 1607, 1582, 1479, 1313,
1140, 1074, 1012, 752 cmꢁ1. MS (EI) m/z 396 (Mþ, 15).
Anal. Calcd for C25H20N2O3: C, 75.74; H, 5.08; N, 7.07.
Found: C, 75.67; H, 5.16; N, 7.03. Mp¼197.5 ꢀC.
C30H24N2O4: C, 75.61; H, 5.08; N, 5.88. Found: C, 75.88;
H, 5.10; N, 5.86. Mp¼241.5 ꢀC.
4.6. X-ray crystallographic analysis
4.6.1. X-ray crystallographic analysis of 5b
Single crystals of 5b suitable for X-ray diffraction study
were obtained by recrystallization from hexane/ether/CH2Cl2
at rt. X-ray data were collected on a Rigaku Saturn CCD dif-
fractometer with graphite-monochromated Mo Ka radiation
˚
(l 0.71070 A). The data were corrected for Lorentz and polar-
ization effects. The structures were solved by direct methods
and refined by full-matrix least-squares against F2 using the
CrystalStructure crystallographic software package.24,25
4.5.29. 1,2-Dihydrobenzo[g]phthalazine derivative (5b)
1
Light yellow solid; H NMR (CDCl3, 400 MHz) d 9.09 (s,
4.6.2. Crystal data of 1,2-dihydrobenzo[g]phthalazine
derivative (5b)
1H), 8.38 (s, 1H), 7.96 (m, 3H), 7.88 (d, J¼7.6 Hz, 1H), 7.69
(ddd, J¼8.2, 7.2, 1.2 Hz, 1H), 7.53 (m, 2H), 7.38 (d,
J¼7.2 Hz, 2H), 7.21 (dd, J¼8.2, 6.8 Hz, 2H), 7.16 (d,
J¼6.8 Hz, 1H), 7.12 (d, J¼7.6 Hz, 1H), 3.31 (dt, J¼16.4,
7.6 Hz, 1H), 3.23 (dt, J¼16.4, 7.2 Hz, 1H), 1.91 (dddq,
J¼7.6, 7.2, 7.2, 2.0 Hz, 2H), 1.13 (t, J¼7.2 Hz, 3H). 13C
NMR (CDCl3, 100 MHz) d 199.5, 160.8, 143.9, 141.6, 138.3,
136.0, 134.0, 132.8, 130.3, 129.4, 129.3, 129.0, 128.0, 127.9,
127.3, 126.9, 124.9, 124.4, 123.4, 117.1, 115.6, 114.8, 90.5,
40.8, 18.3, 14.1. IR (KBr): 2961, 1747, 1686, 1481, 1362,
1312, 1240, 1202, 1053, 887 cmꢁ1. MS (EI) m/z 446 (Mþ,
33). Anal. Calcd for C29H22N2O3: C, 78.01; H, 4.97; N, 6.27.
Found: C, 78.08; H, 5.03; N, 6.29. Mp¼239.5 ꢀC.
C29H22N2O3, Mw¼446.50, colorless prism, 0.40ꢂ0.30ꢂ
0.10 mm, monoclinic, space group P21/n (no. 14), a¼
ꢀ
ꢁ1
˚
˚
˚
11.824(5) A, b¼9.473(4) A, c¼19.655(9) A, b¼94.7817(15) ,
3
˚
V¼2193.8(16) A , T¼173 K, Z¼4, m(Mo Ka)¼0.881 cm
,
27,676 reflections measured, 4874 unique (Rint¼0.043). The
final R1 and wR2 were 0.0371 (I>2.00s(I )) and 0.0810 (for
all data), respectively. Crystallographic data (excluding struc-
ture factors) for the structure of 5b have been deposited with
the Cambridge Crystallographic Data Center as supplementary
publication no. CCDC 654091. Copies of the data can be ob-
tained, free of charge, on application to CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (fax: þ44 (0)1223 336033 or
e-mail: deposit@ccdc.cam.ac.uk).
4.5.30. 1,2-Dihydrobenzo[g]phthalazine derivative (5c)
1
Yellow solid; H NMR (CDCl3, 400 MHz) d 9.12 (s, 1H),
Acknowledgements
8.58 (s, 1H), 8.38 (s, 1H), 8.26 (s, 1H), 7.96e7.83 (m, 4H),
7.60 (ddd, J¼8.0, 6.8, 1.2 Hz, 1H), 7.55 (ddd, J¼8.8, 6.8,
2.0 Hz, 1H), 7.52 (ddd, J¼8.4, 6.8, 1.6 Hz, 1H), 7.43 (m,
3H), 7.18 (m, 2H), 7.10 (m, 1H), 3.39 (dt, J¼16.4, 7.6 Hz,
1H), 3.30 (dt, J¼16.4, 7.6 Hz, 1H), 1.96 (ddq, J¼7.6, 7.6,
7.2 Hz, 2H), 1.18 (t, J¼7.2 Hz, 3H). 13C NMR (CDCl3,
100 MHz) d 199.7, 161.5, 141.9, 139.4, 138.2, 137.1, 133.9,
133.0, 132.9, 129.8, 129.5, 129.4, 129.3, 129.2, 129.0,
129.0, 128.1, 127.9, 127.4, 127.3, 126.8, 125.7, 125.0,
124.5, 117.2, 115.1, 112.5, 90.9, 40.8, 18.4, 14.2. IR (KBr):
This work was supported in part by a Grant-in-Aid for
Scientific Research (B) (No. 18350091) from the Ministry of
Education, Culture, Sports, Science, and Technology, Japan.
References and notes
1. For reviews, see: (a) Hoffmann, R. W. Dehydrobenzene and Cycloalkynes;
Academic: New York, NY, 1967; (b) Biehl, E. R.; Khanapure, S. P. Acc.
Chem. Res. 1989, 22, 275e281; (c) Kessar, S. V. Comprehensive Organic
Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon: New York, NY,
1991; Vol. 4, pp 483e515; (d) Buchward, S. L.; Broene, R. D. Comprehen-
sive Organometallic Chemistry II; Able, E. W., Stone, F. G. A., Willkinson,
G., Eds.; Pergamon: Oxford, UK, 1995; Vol. 12, pp 771e784; (e) Pellissier,
H.; Santelli, M. Tetrahedron 2003, 59, 701e730; (f) Wenk, H. H.; Winkler,
M.; Sander, W. Angew. Chem., Int. Ed. 2003, 42, 502e528.
2. For recent examples, see: (a) Schuster, I. I.; Craciun, L.; Ho, D. M.; Pascal,
R. A., Jr. Tetrahedron 2002, 58, 8875e8882; (b) Duong, H. M.; Bendikov,
M.; Steiger, D.; Zhang, Q.; Sonmez, G.; Yamada, J.; Wudl, F. Org. Lett.
2003, 5, 4433e4436; (c) Lu, J.; Ho, D. M.; Vogelaar, N. J.; Kraml, C. M.;
Pascal, R. A., Jr. J. Am. Chem. Soc. 2004, 126, 11168e11169; (d) Ikadai,
J.; Yoshida, H.; Ohshita, J.; Kunai, A. Chem. Lett. 2005, 34, 56e57;
(e) Hayes, M. E.; Shinokubo, H.; Danheiser, R. L. Org. Lett. 2005, 7,
3917e3920; (f) Dockendorff, C.; Sahli, S.; Olsen, M.; Milhau, L.;
Lautens, M. J. Am. Chem. Soc. 2005, 127, 15028e15029; (g) Shou, W.-G.;
Yang, Y.-Y.; Wang, Y.-G. J. Org. Chem. 2006, 71, 9241e9243.
2967, 1734, 1672, 1628, 1558, 1063, 934, 546, 467 cmꢁ1
.
Anal. Calcd for C33H24N2O3: C, 79.82; H, 4.87; N, 5.64.
Found: C, 79.53; H, 4.93; N, 5.58. Mp¼236.5 ꢀC.
4.5.31. 1,2-Dihydrobenzo[g]phthalazine derivative (5d)
1
Orange solid; H NMR (CDCl3, 400 MHz) d 9.26 (s, 1H),
7.99 (d, J¼8.0 Hz, 1H), 7.70e7.47 (m, 8H), 7.33e7.17 (m,
4H), 3.99 (s, 3H), 3.14 (dt, J¼16.0, 7.6 Hz, 1H), 3.00 (dt,
J¼16.0, 7.8 Hz, 1H), 1.82 (ddq, J¼7.8, 7.6, 7.2 Hz, 2H),
1.03 (t, J¼7.2 Hz, 3H). 13C NMR (CDCl3, 100 MHz)
d 200.3, 162.0, 152.6, 141.6, 140.0, 133.5, 133.5, 133.2,
129.4, 129.3, 128.7, 128.5, 128.1, 127.6, 127.5, 127.4,
127.4, 126.7, 126.5, 123.6, 120.7, 117.9, 117.2, 91.3, 56.5,
40.7, 18.2, 14.1. IR (KBr): 2945, 1869, 1684, 1636, 1522,
3. Logullo, F. M.; Seitz, A. H.; Friedman, L. Org. Synth. 1973, Coll. Vol. V,
54e59.
1489, 1364, 1053, 756, 519 cmꢁ1
. Anal. Calcd for

796
4. Asao, N.; Sato, K. Org. Lett. 2006, 8, 5361e5363.
5. For highlights and reviews on the Au-catalyzed reactions, see: (a) Dyker,
G. Angew. Chem., Int. Ed. 2000, 39, 4237e4239; (b) Hashmi, A. S. K.
Gold Bull. 2003, 36, 3e9; (c) Hashmi, A. S. K. Gold Bull. 2004, 37,
51e65; (d) Arcadi, A.; Di Giuseppe, S. Curr. Org. Chem. 2004, 8,
K. Sato et al. / Tetrahedron 64 (2008) 787e796
14. (a) Marks, V.; Nahmany, M.; Gottlieb, H. E.; Biali, S. E. J. Org. Chem.
2002, 67, 7898e7901; (b) Lu, J.; Zhang, J.; Shen, X.; Ho, D. M.; Pascal,
R. A., Jr. J. Am. Chem. Soc. 2002, 124, 8035e8041; (c) Iiba, E.; Hirai, K.;
Tomioka, H.; Yoshioka, Y. J. Am. Chem. Soc. 2002, 124, 14308e14309;
(d) Spyroudis, S.; Xanthopoulou, N. J. Org. Chem. 2002, 67, 4612e
4614; (e) Spyroudis, S.; Xanthopoulou, N. Tetrahedron Lett. 2003, 44,
3767e3770; (f) Zhu, X. Z.; Chen, C. F. J. Org. Chem. 2005, 70, 917e924.
15. (a) Perchellet, E. M.; Magill, M. J.; Huang, X.; Brantis, C. E.; Hua, D. H.;
Perchellet, J.-P. Anti-Cancer Drugs 1999, 10, 749e766; (b) Yang, W.;
Perchellet, E. M.; Tamura, M.; Hua, D. H.; Perchellet, J. P. Cancer Lett.
2002, 188, 73e83; (c) Hua, D. H.; Tamura, M.; Huang, X.; Stephany,
H. A.; Helfrich, B. A.; Perchellet, E. M.; Sperfslage, B. J.; Perchellet,
J.-P.; Jiang, S.; Kyle, D. E.; Chiang, P. K. J. Org. Chem. 2002, 67,
2907e2912; (d) Perchellet, E. M.; Wang, Y.; Weber, R. L.; Lou, K.;
Hua, D. H.; Perchellet, J.-P. H. Anti-Cancer Drugs 2004, 15, 929e
946; (e) Wang, Y.; Perchellet, E. M.; Ward, M. M.; Lou, K.; Zhao,
H.; Battina, S. K.; Wiredu, B.; Hua, D. H.; Perchellet, J.-P. H.
Int. J. Oncol. 2006, 28, 161e172.
795e812; (e) Hoffmann-Roder, A.; Krause, N. Org. Biomol. Chem.
¨
2005, 3, 387e391; (f) Hashmi, A. S. K. Angew. Chem., Int. Ed. 2005,
44, 6990e6993; (g) Ma, S.; Yu, S.; Gu, Z. Angew. Chem., Int. Ed.
2006, 45, 200e203; (h) Zhang, L.; Sun, J.; Kozmin, S. A. Adv. Synth.
Catal. 2006, 348, 2271e2296; (i) Hashmi, A. S. K.; Hutchings, G. J.
´
´~
Angew. Chem., Int. Ed. 2006, 45, 7896e7936; (j) Jimenez-Nunez, E.;
Echavarren, A. M. Chem. Commun. 2007, 333e346; (k) Gorin, D. J.;
Toste, F. D. Nature 2007, 446, 395e403.
6. (a) Asao, N.; Takahashi, K.; Lee, S.; Kasahara, T.; Yamamoto, Y. J. Am.
Chem. Soc. 2002, 124, 12650e12651; (b) Asao, N.; Nogami, T.; Lee, S.;
Yamamoto, Y. J. Am. Chem. Soc. 2003, 125, 10921e10925; (c) Asao, N.;
Sato, K.; Menggenbateer; Yamamoto, Y. J. Org. Chem. 2005, 70, 3682e
3685; (d) Sato, K.; Asao, N.; Yamamoto, Y. J. Org. Chem. 2005, 70,
8977e8981; (e) Asao, N. Synlett 2006, 1645e1656.
16. (a) Marc Veen, E.; Postma, P. M.; Jonkman, H. T.; Spek, A. L.; Feringa, B. L.
Chem. Commun. 1999, 1709e1710; (b) Yang, J.-S.; Liu, C.-P.; Lee, G.-H.
Tetrahedron Lett. 2000, 41, 7911e7915; (c) Yang, J.-S.; Lee, C.-C.; Yau,
S.-L.; Chang, C.-C.; Lee, C.-C.; Leu, J.-M. J. Org. Chem. 2000, 65, 871e
877; (d) Yang, J.-S.; Liu, C.-P.; Lin, B. C.; Tu, C. W.; Lee, G. H. J. Org.
Chem. 2002, 67, 7343e7354; (e) Zhu, X. Z.; Chen, C. F. J. Am. Chem.
Soc. 2005, 127, 13158e13159; (f) Zong, Q. S.; Chen, C. F. Org. Lett.
2006, 8, 211e214; (g) Han, T.; Chen, C. F. Org. Lett. 2006, 8, 1069e
1072; (h) Zong, Q. S.; Zhang, C.; Chen, C. F. Org. Lett. 2006, 8, 1859e
1862; (i) Peng, X.-X.; Lu, H.-Y.; Han, T.; Chen, C.-F. Org. Lett. 2007, 9,
895e898; (j) Han, T.; Zong, Q. S.; Chen, C.-F. J. Org. Chem. 2007, 72,
3108e3111;(k)Zhang, C.;Chen, C.-F. J. Org. Chem. 2007, 72, 3880e3888.
17. (a) Norvez, S. J. Org. Chem. 1993, 58, 2414e2418; (b) Yang, J.-S.; Swager,
T. M. J. Am. Chem. Soc. 1998, 120, 5321e5322; (c) Yang, J.-S.; Swager,
T. M. J. Am. Chem. Soc. 1998, 120, 11864e11873; (d) Yang, J.-S.;
Lin, C.-S.; Hwang, C.-Y. Org. Lett. 2001, 3, 889e892; (e) Long, T. M.;
Swager, T. M. J. Am. Chem. Soc. 2002, 124, 3826e3827; (f) Zhu, Z.; Swager,
T. M. J. Am. Chem. Soc. 2002, 124, 9670e9671; (g) Long, T. M.; Swager,
T. M. J. Am. Chem. Soc. 2003, 125, 14113e14119.
7. Other examples of benzannulation with gold catalyst, see: (a) Hashmi,
A. S. K.; Frost, T. M.; Bats, J. W. J. Am. Chem. Soc. 2000, 122,
11553e11554; (b) Hashmi, A. S. K.; Frost, T. M.; Bats, J. W. Org.
Lett. 2001, 3, 3769e3771; (c) Dankwardt, J. W. Tetrahedron Lett. 2001,
42, 5809e5812; (d) Hashmi, A. S. K.; Frost, T. M.; Bats, J. W. Catal.
Today 2002, 72, 19e27; (e) Mamane, V.; Hannen, P.; Furstner, A.
¨
Chem.dEur. J. 2004, 10, 4556e4575; (f) Hashmi, A. S. K.; Rudolph,
M.; Weyrauch, J. P.; Wolfle, M.; Frey, W.; Bats, J. W. Angew. Chem.,
¨
Int. Ed. 2005, 44, 2798e2801; (g) Dyker, G.; Hildebrandt, D. J. Org.
Chem. 2005, 70, 6093e6096; (h) Shibata, T.; Fujiwara, R.; Takano, D.
Synlett 2005, 2062e2066; (i) Shibata, T.; Ueno, Y.; Kanda, K. Synlett
2006, 411e414; (j) Zhao, J.; Hughes, C. O.; Toste, F. D. J. Am. Chem.
Soc. 2006, 128, 7436e7437; (k) Lian, J.-J.; Lin, C.-C.; Chang, H.-K.;
Chen, P.-C.; Liu, R.-S. J. Am. Chem. Soc. 2006, 128, 9661e9667; (l)
Hildebrandt, D.; Dyker, G. J. Org. Chem. 2006, 71, 6728e6733; (m)
Lian, J.-J.; Liu, R.-S. Chem. Commun. 2007, 1337e1339; (n) Oh, C. H.;
Kim, A.; Park, W.; Park, D. I.; Kim, N. Synlett 2006, 2781e2784.
8. Benzo[c]pyrylium salts are known to play a diene part in the DielseAlder
reaction with ethyl vinyl ether, see: Kuznetsov, E.; Shcherbakova, I. V.;
Balaban, A. T. Adv. Heterocycl. Chem. 1990, 50, 157e254.
18. (a) Iwamura, H.; Mislow, K. Acc. Chem. Res. 1988, 21, 175e182; (b)
Kelly, T. R.; Bowyer, M. C.; Bhaskar, K. V.; Bebbington, D.; Garcia,
A.; Lang, F.; Kim, M. H.; Jette, M. P. J. Am. Chem. Soc. 1994, 116,
3657e3658; (c) Kelly, T. R.; Silva, R. A.; Silva, H. D.; Jasmin, S.;
Zhao, Y. J. Am. Chem. Soc. 2000, 122, 6935e6949; (d) Godinez, C. E.;
Zepeda, G.; Garcia-Garibay, M. A. J. Am. Chem. Soc. 2002, 124,
4701e4707; (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Raimondi,
L.; Cozzi, F. J. Phys. Org. Chem. 2004, 17, 749e751.
19. (a) Stiles, M.; Miller, R. G. J. Am. Chem. Soc. 1960, 82, 3802; (b)
Friedman, L.; Logullo, F. M. J. Am. Chem. Soc. 1963, 85, 1549.
20. Burckhardt, U.; Hintermann, L.; Schnyder, A.; Togni, A. Organometallics
1995, 14, 5415e5425.
21. (a) Franklin, E. C. Chem. Rev. 1935, 16, 305e361; (b) Bergstrom, F. W.
Chem. Rev. 1944, 35, 77e277; (c) Lichtenthaler, F. W. Acc. Chem. Res.
2002, 35, 728e737; (d) Litvinov, V. P. Russ. Chem. Rev. 2003, 72, 69e
85; (e) Xu, Y.; Guo, Q.-X. Heterocycles 2004, 63, 903e974.
22. (a) Padwa, A.; Waterson, A. G. Curr. Org. Chem. 2000, 4, 175e203; (b)
Orru, R. V. A.; de Greef, M. Synthesis 2003, 1471e1499; (c) Kirsch, G.;
Hesse, S.; Comel, A. Curr. Org. Chem. 2004, 1, 47e63.
23. (a) Yamashita, Y.; Hayashi, T.; Masumura, M. Chem. Lett. 1980, 1133e
1136; (b) Compagnini, A.; Lo Vullo, A.; Chiacchio, U.; Corsaro, A.;
Purrello, G. J. Heterocycl. Chem. 1982, 19, 641e643; (c) Atanes, N.;
Guitian, E.; Saa, C.; Castedo, L.; Saa, J. M. Tetrahedron Lett. 1987,
28, 817e820; (d) Al-Rawi, J. M. A.; Khayat, M. A. R. Magn. Reson.
Chem. 1989, 27, 112e116; (e) Agawa, C.; Otsuka, K.; Minoura, M.;
Mazaki, Y.; Yamamoto, G. Bull. Chem. Soc. Jpn. 2004, 77, 2273e2281.
24. CrystalStructure 3.7.0: Crystal Structure Analysis Package, Rigaku and
Rigaku/MSC; 9009 New Trails Dr.: The Woodlands, TX 77381, USA,
2000e2005.
9. For a review, see: Nogradi, M. Science of Synthesis: HoubeneWeyl
Methods of Molecular Transformations; Georg Thieme: Stuttgart,
Germany, 2003; Vol. 14, pp 201e273.
10. Tovar, J. D.; Swager, T. M. J. Org. Chem. 1999, 64, 6499e6504.
11. For examples of reactions with pyrylium intermediates, see: (a)
´
´
Barluenga, J.; Vazquez-Villa, H.; Ballesteros, A.; Gonzalez, J. M.
J. Am. Chem. Soc. 2003, 125, 9028e9029; (b) Barluenga, J.;
´
´
Vazquez-Villa, H.; Ballesteros, A.; Gonzalez, J. M. Org. Lett. 2003, 5,
4121e4123; (c) Zhu, J.; Germain, A. R.; Porco, J. A., Jr. Angew.
Chem., Int. Ed. 2004, 43, 1239e1243; (d) Kusama, H.; Funami, H.;
Takaya, J.; Iwasawa, N. Org. Lett. 2004, 6, 605e608; (e) Yue, D.; Ca,
N. D.; Larock, R. C. Org. Lett. 2004, 6, 1581e1584; (f) Sato, K.;
Yudha, S. S.; Asao, N.; Yamamoto, Y. Synthesis 2004, 1409e1412; (g)
´
´
Barluenga, J.; Vazquez-Villa, H.; Ballesteros, A.; Gonzalez, J. M. Adv.
Synth. Catal. 2005, 347, 526e530; (h) Kusama, H.; Funami, H.; Shido,
M.; Hara, Y.; Takaya, J.; Iwasawa, N. J. Am. Chem. Soc. 2005, 127,
2709e2716; (i) Kim, N.; Kim, Y.; Park, W.; Sung, D.; Gupta, A. K.;
Oh, C. H. Org. Lett. 2005, 7, 5289e5291; (j) Gupta, A. K.; Rhim,
C. Y.; Oh, C. H.; Maneb, R. S.; Han, S.-H. Green Chem. 2006, 8,
´
25e28; (k) Yue, D.; Ca, N. D.; Larock, R. C. J. Org. Chem. 2006,
71, 3381e3388.
12. Bartlett, P. D.; Ryan, M. J.; Cohen, S. G. J. Am. Chem. Soc. 1942, 64,
2649e2653.
13. (a) Norvez, S.; Barzoukas, M. Chem. Phys. Lett. 1990, 165, 41e44; (b)
Korth, O.; Wiehe, A.; Kurreck, H.; Roder, B. Chem. Phys. 1999, 246,
¨
363e372; (c) Beyeler, A.; Belser, P. Coord. Chem. Rev. 2002, 230, 28e
38; (d) Perepichka, D. F.; Bendikov, M.; Meng, H.; Wudl, F.
J. Am. Chem. Soc. 2003, 125, 10190e10191; (e) Satrijo, A.; Swager,
T. M. Macromolecules 2005, 38, 4054e4057.
25. Watkin, D. J.; Prout, C. K.; Carruthers, J. R.; Betteridge, P. W. CRYSTALS
Issue 10; Chemical Crystallography Laboratory: Oxford, UK, 1996.