Highly Selective and Modular Synthesis of 3-Aryl-4-(arylethynyl)-2H-chromen-2-ones from 2-Iodoaryl 2-Arylacetates through a Carbonylative Sonogashira Coupling–Intramolecular Aldol Cascade Reaction

Article abstract of DOI:10.1002/ejoc.201600569

A modular method for the synthesis of 3-aryl-4-(arylethynyl)-2H-chromen-2-ones from 2-iodoaryl 2-arylacetates and arylacetylenes has been developed. The carbonylative Sonogashira coupling–intramolecular aldol casade reaction was carried out in the presence of Pd(PPh₃)₂(Cl)₂as the catalyst. The one-pot approach that involves the in situ formation of the 2-iodoaryl 2-arylacetates from the corresponding 2-iodophenols and 2-arylacetyl chlorides followed by the palladium-catalyzed carbonylative annulation in the presence of the arylacetylene has also been described for the formation of the 3-aryl-4-(arylethynyl)-2H-chromen-2-ones.

Full text of DOI:10.1002/ejoc.201600569

DOI: 10.1002/ejoc.201600569
Full Paper
Carbonylative Annulation
Highly Selective and Modular Synthesis of 3-Aryl-4-
arylethynyl)-2H-chromen-2-ones from 2-Iodoaryl 2-Arylacetates
(
through a Carbonylative Sonogashira Coupling–Intramolecular
Aldol Cascade Reaction
[a]
[a]
[a]
Attoor Chandrasekhar, Venkatachalam Ramkumar, and Sethuraman Sankararaman*
Dedicated to Professor Dr. Henning Hopf on the occasion of his 75th birthday
Abstract: A modular method for the synthesis of 3-aryl-4-(aryl- aryl 2-arylacetates from the corresponding 2-iodophenols and
ethynyl)-2H-chromen-2-ones from 2-iodoaryl 2-arylacetates and 2-arylacetyl chlorides followed by the palladium-catalyzed
arylacetylenes has been developed. The carbonylative Sonoga- carbonylative annulation in the presence of the arylacetylene
shira coupling–intramolecular aldol casade reaction was carried has also been described for the formation of the 3-aryl-4-(aryl-
out in the presence of Pd(PPh ) (Cl) as the catalyst. The one- ethynyl)-2H-chromen-2-ones.
3
2
2
pot approach that involves the in situ formation of the 2-iodo-
Introduction
2-iodoaryl 2-arylacetate and arylacetylene in the presence of
Pd(PPh ) (Cl) as the catalyst under carbon monoxide (1 atm).
3
2
2
2H-Chromen-2-one (coumarin) and its derivatives are found in
[9]
An earlier report
of the synthesis of 4-arylethynyl-2H-
[
1]
nature, especially in the plant kingdom. They are an impor-
tant class of compounds as they display a wide range of biolog-
chromen-2-ones used 4-hydroxycoumarin as the starting mate-
rial. In that report, the tosylates of 4-hydroxycoumarins were
generated in situ and subjected to palladium-catalyzed Sonoga-
shira coupling reactions with terminal acetylenes.
[
2]
ical activities and also have applications in materials chemis-
try as laser dyes, light-emitting diodes, and fluorescent
[
3]
probes. The conventional synthesis of 2H-chromen-2-one by
[
4]
[5]
using a Perkin or von Pechmann reaction involves the con-
densations of substituted phenols with various carbonyl com-
pounds. Modern transition-metal-mediated catalytic methods
involve carbonylative annulation reactions that use carbon
monoxide as a one-carbon source. Cobalt(III)-catalyzed carbon-
ylative annulations of 2-alkenylphenols to give coumarin deriva-
Results and Discussion
The 2-iodoaryl 2-arylacetates 1a–g were synthesized according
to a literature method by employing the reaction between the
[
6]
tives have been reported, and this approach requires the syn-
thesis of 2-alkenylphenols from the corresponding salicylalde-
hyde derivatives by a Wittig reaction. Palladium-catalyzed
carbonylative annulations of internal alkynes and 2-iodo-
phenols have been reported to give regioisomeric mixtures of
corresponding 2-iodophenol and 2-arylacetyl chloride deriva-
[10]
tives.
The carbonylative annulation reactions of 1a–g with
arylacetylenes 2a–e were then carried out in toluene at 80 °C,
as there was no reaction at room temperature (Scheme 1).
These reactions were performed in the presence of
Pd(PPh ) (Cl) (1 mol-%) as the catalyst and a balloon filled with
3
,4-disubstituted coumarins from unsymmetrical internal alk-
3
2
2
[
7]
ynes. In a related work, two examples of the synthesis of 3,4-
disubstituted coumarins through a carbonylative annulation of
CO (1 atm), and the progress of the reactions was monitored by
TLC analysis. Under these conditions, the reactions proceeded
cleanly and selectively towards the formation of coumarin de-
rivatives 3a–v and 3y (Scheme 1) in high yields, and the corre-
sponding Sonogashira coupling products, namely the 2-(aryl-
ethynyl)phenyl 2-arylacetates, were not observed. The absence
of the Sonogashira coupling product suggests that the carbon-
2-iodophenyl 3-alkenoate have been reported along with de-
[
8]
tails of the formation of an aurone derivative as a byproduct.
Herein, we report a general and modular synthetic method for
the synthesis of 3-aryl-4-(arylethynyl)-2H-chromen-2-ones from
0
[
a] Department of Chemistry, Indian Institute of Technology Madras,
Chennai 600036, India
ylation reaction that follows the oxidative addition of Pd across
the C–I bond occurs much faster than the Sonogashira coupling
reaction. Small amounts of 1,4-diarylbuta-1,3-diynes were ob-
tained, presumably from the oxidative dimerization of the aryl-
acetylenes.
E-mail: sanka@iitm.ac.in
http://chem.iitm.ac.in/faculty/sankararaman
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/ejoc.201600569.
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trimethylsilylacetylene (2f) proceeded smoothly to give 3w in
7
8 % yield. Deprotection of the trimethylsilyl group of 3w by
using (n-C H ) NF gave the terminal acetylene derivative 3x in
4
9 4
8
0 % yield (Scheme 2).
Scheme 1. Synthesis of 3-aryl-4-(arylethynyl)-2H-chromen-2-ones from 2-
iodoaryl 2-arylacetates.
Figure 1. Ellipsoid representation (50 % probability) of the crystal structures
of 3h (left) and 3p (right).
The effect of the palladium source on the reaction between
1
a and 2a was also examined by using Pd(OAc) . In this case,
2
small amounts of the (noncarbonylative) Sonogashira coupling
product were produced along with 3a in 72 % yield. The reac-
tion of methoxy derivative 1b was slower than that of the other
substrates, and trace amounts of the starting material were re-
covered even after 24 h. The electron-donating nature of the
methoxy substituent with the decreased acidity of the CH pro-
2
tons provides an explanation for this change in the reaction
rate. The synthesis is modular as the substituents of the three
aromatic rings can be independently varied, which is illustrated
by the examples shown in Scheme 1 and Table 1. In all of the
cases, the products were purified by column chromatography
on silica gel and characterized by spectroscopic data. The struc-
tures of 3h and 3p were unambiguously established by single
crystal XRD data (Figure 1). Moreover, the reaction of 1a with
Scheme 2. Synthesis of 3w and then 3x from the reaction of 1a with trimeth-
ylsilylacetylene (TMS = trimethylsilyl).
The feasibility of a one-pot synthesis of 3 was then investi-
gated by sequentially adding the reagents of the two steps.
Initially, to a mixture of the 2-iodophenol and triethylamine
(3 equiv.) in toluene was added 2-phenylacetyl chloride
Table 1. Substrate scope for the synthesis of 3-aryl-4-(arylethynyl)-2H-
chromen-2-ones 3a–v and 3y from 2-iodoaryl 2-arylacetates 1a–g.
(1.1 equiv.). This mixture was stirred at room temperature for
Entry
R1
R2
R3
Time [h]
% Yield 3
30 min followed by the addition of phenylacetylene (1.1 equiv.)
and Pd(PPh ) (Cl) (1 mol-%) and then finally CO. The one-pot
3
2
2
1
2
3
4
5
6
7
8
9
H
H
H
H
4-tBu
4-tBu
H
H
H
4-tBu
4-tBu
H
H
H
4-tBu
H
4-tBu
H
H
H
H
H
H
H
H
H
H
4
10
3
6
4
3
4
10
4
5
4
5
5
6
4
6
6
8
91 (3a)
76 (3b)
95 (3c)
70 (3d)
90 (3e)
92 (3f)
90 (3g)
71 (3h)
91 (3i)
89 (3j)
90 (3k)
86 (3l)
89 (3m)
74 (3n)
86 (3o)
81 (3p)
90 (3q)
79 (3r)
82 (3s)
75 (3t)
70 (3u)
77 (3v)
87 (3y)
strategy yielded (after chromatographic purification) 72 % of 3a
and 77 % of 3e from the reactions of 2a with iodophenol and
4-OMe
4-Br
4-NO
H
4-Br
H
4-OMe
4-Br
H
4-Br
H
4-Br
4-NO
4-Br
H
2
4
-tert-butyl-2-iodophenol, respectively (Scheme 3).
4-Me
4-Me
4-Me
4-Me
4-Me
2-Me
2-Me
2-Me
2-Me
2,4,6-Me
2,4,6-Me
4-OMe
4-OMe
4-OMe
4-OMe
4-OMe
H
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Scheme 3. One-pot synthesis of 3a and 3e by the sequential addition of
reagents.
2
3
3
From the results in Table 1, it is evident that this method is
fairly general and modular in nature and allows for the inde-
pendent variation of the substituents on the three aryl rings to
synthesize a variety of coumarin derivatives (i.e., 3a–3y) in good
to excellent yields. Several functional groups such as the chloro,
bromo, nitro, and methoxy substituents were tolerated under
the reaction conditions. Compound 3x, which contains a termi-
H
H
4-Br
4-NO
H
4-Br
H
8
8
10
8
5
2
4-tBu
4-tBu
4-Cl
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Full Paper
nal acetylene group, could serve as a starting material in a syn- 2H-chromen-2-one derivative. Instead, the reaction yielded the
thesis designed for further structural diversity.
The attempted synthesis of 4-(arylethynyl)-2H-chromen-2- (Scheme 6). A control experiment revealed that the deiodina-
ones from 2-iodophenyl acetate (4a) and 4-tert-butyl-2-iodo- tion of 9 also occurred in the absence of CO (under N ). The
product of deiodination (i.e., 10) in almost quantitative yield
2
phenyl acetate (4b) under the conditions described in reaction of 1-iodo-2-naphthyl acetate (11) under identical con-
Scheme 1 gave only the carbonylative Sonogashira coupling ditions gave only the corresponding Sonogashira coupling
products 5a and 5b, respectively, in nearly quantitative yields product 12, and neither the carbonylative Sonogashira cou-
(
Scheme 4). The anticipated carbonylative annulation products, pling product nor the carbonylative annulation product was ob-
namely the corresponding chromen-2-ones, were not observed served in this reaction (Scheme 6). In the case of 4a and 4b,
in these reactions. The differences in the reactivities between the oxidative addition and carbonylation reaction sequence oc-
1
a and 4a and those between 1b and 4b can be explained by curred faster than the Sonogashira coupling of the alkyne,
higher acidities of the CH protons of 1a and 1b compared with whereas in the case of 11, the latter process was faster than
2
[
11]
those of the CH protons of 4a and 4b (ΔpK ≈ 7.0 units ). the carbonylation reaction. The absence of the carbonylation
3
a
The formation of the enolate and its intramolecular aldol reac- reaction in the cases of 9 and 11 is attributed to steric hin-
tion with the newly formed carbonyl group that results from drance at the 1-naphthyl position. The deiodination of 9 com-
the carbonylation reaction is facile in the cases of 1a and 1b petes with the Sonogashira coupling as well as the carbonyl-
compared with that of 4a and 4b.
ation reaction and occurs by protonation of the C–Pd bond by
+
either Et NH or an intramolecular proton transfer from the
3
acidic CH moiety of 9. Because of the lower acidity of 11 com-
2
pared with 9, the protonation did not occur, and the Sonoga-
shira coupling effectively proceeded to form 12 (Scheme 7). A
similar deiodination reaction has been previously reported for
Scheme 4. Attempted carbonylative annulation reaction of 2-iodoaryl
acetates in toluene.
When 4a and 4b were treated with phenylacetylene in tri-
ethylamine as the solvent, a mixture of products 6–8 were
formed (Scheme 5). This type of carbonylative annulation that
yields 2-(aryl)-4H-chromen-4-one has been previously re-
[
12]
ported
to result from the reaction of 2-(3-arylpropiolyl)-
phenyl acetate under basic conditions. Products 6–8 were sepa-
rated by column chromatography and characterized by spectro-
scopic methods. Compounds 6a and 7b were characterized by
single crystal XRD data. The stereochemistry of 8b was assigned
Scheme 6. Attempted synthesis of naphthyl-fused 2H-chromen-2-one.
1
13
by comparing the H and C NMR spectroscopic data of similar
[
13]
aurone derivatives reported in the literature.
Scheme 5. Carbonylative annulation reaction of 2-iodoaryl acetates in tri-
methylamine.
The attempted synthesis of a naphthalene analogue by treat-
ing 9 with phenylacetylene under the identical reaction condi-
tions in Scheme 1 failed to furnish the expected naphthyl-fused
Scheme 7. Plausible reaction mechanism for the formation of 10 and 12.
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the Pd-catalyzed carbonylative annulation of 1-iodo-2-naphthol amine (2 equiv.) in CH
Cl
/tetrahydrofuran (THF; 1:1, 20 mL) was
2
2
[
7b]
added acyl chloride (1.5 equiv.) at 0 °C under N . The reaction mix-
to yield 2-naphthol.
2
ture was stirred at room temperature for 3–5 h and then quenched
with water. The resulting mixture was extracted with CH Cl . The
Finally, the reaction of another sterically hindered iodide,
namely 2-iodo-3,5-dimethylphenyl 2-phenylacetate (13), under
the standard reaction conditions gave only 8 % of the Sonoga-
shira coupled product 14 after 12 h, and neither the corre-
sponding carbonylative Sonogashira coupled product nor the
expected chromen-2-one derivative was obtained. Upon chro-
matographic separation, the starting material 13 was recovered
in 77 % yield (Scheme 8).
2
2
isolated organic layer was washed with brine and dried with
Na SO , and the solvent was removed under vacuum. The crude
2
4
product was purified by flash column chromatography (EtOAc/hex-
ane, 1:19 v/v) on silica gel.
2-Iodophenyl 2-Phenylacetate (1a): 2-Iodophenol (1 g, 4.5 mmol),
2-phenylacetyl chloride (1.06 g, 6.9 mmol), and Et N (1.3 mL) af-
3
1
forded 1a (1.5 g, 98 % yield) as a yellow oil, H NMR (400 MHz,
CDCl ): δ = 7.81 (dd, J = 8, 1.6 Hz, 1 H), 7.45–7.32 (m, 6 H), 7.07 (dd,
3
1
3
J = 8, 1.2 Hz, 1 H), 6.98–6.94 (m, 1 H), 3.94 (s, 2 H) ppm. C NMR
(
1
100 MHz, CDCl ): δ = 169.2, 151.3, 139.5, 133.1, 129.8, 129.5, 128.8,
3
–
1
27.7, 127.5, 123.0, 90.3, 41.5 ppm. IR: ν˜ = 1758 cm . HRMS (ESI):
+
calcd. for C H O IK [M + K] 376.9441; found 376.9422.
14 11 2
2-Iodophenyl 2-(4-Methoxyphenyl)acetate (1b): 2-Iodophenol
(
1 g, 4.5 mmol), 4-nitrophenylacetyl chloride (1.3 g, 6.9 mmol), and
Scheme 8. Attempted carbonylative Sonogashira coupling-aldol cascade re-
action of sterically hindered iodide 13.
1
Et N (1.3 mL) afforded 1b (1.5 g, 91 % yield) as a pale yellow oil. H
NMR (400 MHz, CDCl ): δ = 7.80 (dd, J = 8, 1.6 Hz, 1 H), 7.35–7.31
3
3
(
(
m, 3 H), 7.05 (dd, J = 8, 1.2 Hz, 1 H), 6.97–6.93 (m, 1 H), 6.97–6.88
m, 2 H), 3.87 (s, 2 H), 3.81 (s, 3 H) ppm. 13C NMR (100 MHz, CDCl3):
δ = 169.6, 159.0, 151.2, 139.5, 130.8, 129.5, 127.7, 125.1, 123.0, 114.1,
Conclusions
–
1
9
0.5, 55.4, 40.6 ppm. IR (KBr): ν˜ = 1759 cm . HRMS (ESI): calcd. for
+
C H O INa [M + Na] 390.9807; found 390.9813.
15 13 3
We have developed a modular carbonylative annulation
method for the synthesis of 3-aryl-4-(arylethynyl)-2H-chromen- 2-Iodophenyl 2-(4-Bromophenyl)acetate (1c): 2-Iodophenol (1 g,
2
-ones from 2-iodoaryl 2-arylacetates and arylacetylenes under 4.5 mmol), 4-bromophenylacetyl chloride (1.6 g, 6.9 mmol), and
Et N (1.3 mL) afforded 1c (1.8 g, 94 % yield) as a pale yellow solid;
CO (1 atm) in toluene at 80 °C in the presence of 1 mol-% of
readily available Pd(PPh ) (Cl) as the catalyst. By starting from
readily available 2-iodophenols, the one-pot synthesis of the
H-chromen-2-one derivatives has also been demonstrated by
the sequential addition of reagents. This is a general method for
use with phenyl derivatives as demonstrated by the synthesis
of 24 different 3,4-disubstitued 2H-chromen-2-ones in good to
excellent yields. Sterically hindered iodides 9 and 13, however,
did not yield the expected coumarin derivatives, which might
be a limitation of the present method.
3
1
m.p. 66 °C. H NMR (400 MHz, CDCl ): δ = 7.81 (dd, J = 8, 1.6 Hz, 1
3
3
2
2
H), 7.52–7.48 (m, 2 H), 7.36–7.29 (m, 3 H), 7.06 (dd, J = 8.4, 1.6 Hz,
1
H), 6.99–6.95 (m, 1 H), 3.89 (s, 2 H) ppm. 13C NMR (100 MHz,
2
CDCl ): δ = 168.7, 151.1, 139.5, 132.0, 131.9, 131.5, 129.5, 127.9,
3
–
1
1
22.9, 121.6, 90.3, 40.9 ppm. IR (KBr): ν˜ = 1766 cm . HRMS (ESI):
+
calcd. for C H O BrINa [M + Na] 438.8807; found 438.8805.
14 10 2
2-Iodophenyl 2-(4-Nitrophenyl)acetate (1d): 2-Iodophenol (1 g,
4
.5 mmol), 4-nitrophenylacetyl chloride (1.37 g, 6.9 mmol), and Et N
3
(
1.3 mL) afforded 1d (1.6 g, 90 % yield) as a white solid; m.p. 68 °C.
1
H NMR (400 MHz, CDCl ): δ = 8.23 and 7.60 (AA′BB′ pattern, J =
3
8
7
.8 Hz, 2 H), 7.81 (dd, J = 8, 1.6 Hz, 1 H), 7.62–7.59 (m, 2 H), 7.38–
.33 (m, 1 H), 7.08 (dd, J = 8, 1.2 Hz, 1 H), 7.01–6.96 (m, 1 H), 4.05
Experimental Section
13
(s, 2 H) ppm. C NMR (100 MHz, CDCl ): δ = 167.9, 150.9, 147.5,
3
1
40.3, 139.6, 130.8, 129.6, 128.0, 123.9, 122.9, 90.2, 41.1 ppm. IR
General Methods: Infrared (IR) spectra were recorded on an FTIR
–
1
+
(
4
KBr): ν˜ = 1760 cm . HRMS (ESI): calcd. for C H NO INa [M + Na]
1
14 10
4
spectrometer. The H NMR spectroscopic data were recorded with
05.9552; found 405.9570.
4
00 and 500 MHz spectrometers. Chemical shifts are reported in
ppm, and tetramethylsilane was used as the internal standard. The 4-tert-Butyl-2-iodophenyl 2-Phenylacetate (1e): 4-tert-Butyl-2-
13
C NMR spectroscopic data were recorded with 100 and 125 MHz iodophenol (1 g, 3.6 mmol), phenylacetyl chloride (0.84 g,
spectrometers with complete proton decoupling. Chemical shifts
are reported in ppm, and the residual solvent signals were used
as the internal standard. High resolution mass spectrometry was
performed with an ESI Q-TOF micromass spectrometer equipped
5.4 mmol), and Et
white solid; m.p. 57 °C. H NMR (500 MHz, CDCl
2 Hz, 1 H), 7.44–7.33 (m, 6 H), 6.97 (d, J = 8.5 Hz, 1 H), 3.93 (s, 2 H),
1.29 (s, 9 H) ppm. 13C NMR (125 MHz, CDCl
): δ = 169.4, 151.0,
3
N (1 mL) afforded 1e (1.3 g, 95 % yield) as a
1
): δ = 7.78 (d, J =
3
3
with a Harvard apparatus syringe pump. X-ray crystallographic data 148.9, 136.5, 133.2, 129.8, 128.7, 127.5, 126.6, 122.2, 90.0, 41.5, 34.5,
–
1
were collected on a charge-coupled device (CCD) diffractometer 31.3 ppm. IR (KBr): ν˜ = 1765 cm . HRMS (ESI): calcd. for C18
H O INa
19 2
+
with graphite-monochromator Mo-Kα radiation (λ = 0.71073 Å).
CCDC 1478489 (for 3h), 1478490 (for 3p), 1478491 (for 7b), and
[M + Na] 417.0328; found 417.0320.
-tert-Butyl-2-iodophenyl 2-(4-Bromophenyl)acetate (1f): 4-tert-
Butyl-2-iodophenol (1 g, 3.6 mmol), 4-bromophenylacetyl chloride
1.27 g, 5.4 mmol), and Et N (1 mL) afforded 1f (1.6 g, 95 % yield)
as a white solid; m.p. 81 °C. H NMR (400 MHz, CDCl ): δ = 7.77 (d,
4
1
478492 (for 6a) contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre. Precoated TLC plates (sil-
ica gel 60 F254 grade, 0.25 mm) were used for thin-layer chroma-
tography.
(
3
1
3
J = 2 Hz, 1 H), 7.512–7.47 (m, 2 H), 7.35–7.28 (m, 3 H), 6.96 (d, J =
8
.8 Hz, 1 H), 3.87 (S, 2 H), 1.29 (S, 9 H) ppm. 13C NMR (100 MHz,
General Procedure for the Synthesis 2-Iodophenyl 2-Arylacet-
ates: To a stirred solution of 2-iodophenol (1 equiv.) and triethyl-
CDCl ): δ = 168.9, 151.2, 148.7, 136.5, 132.1, 131.9, 131.5, 126.7,
3
–1
122.1, 121.6, 90.0, 40.9, 34.6, 31.3 ppm. IR (KBr): ν = 1765 cm .
˜
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+
HRMS (ESI): calcd. for C H O BrINa [M + Na] 494.9433; found General Procedure for Carbonylative Annulation Reactions in
1
8 18 2
4
94.9412.
Toluene: To an oven-dried Schlenk tube under N2 were added
PdCl (PPh ) (0.01 equiv.) and toluene (5 mL) followed by 2-iodo-
2
3 2
4
-Chloro-2-iodophenyl 2-Phenylacetate (1g): 4-Chloro-2-iodo-
phenyl 2-phenylacetate (1 equiv.). Then, phenylacetylene
1.1 equiv.) was added along with triethylamine (3 equiv.). The reac-
tion mixture was flushed with CO from a balloon and stirred at
0 °C under CO (1 atm, balloon). After stirring for the period of
phenol (0.5 g, 1.96 mmol), phenylacetyl chloride (0.45 g, 2.9 mmol),
(
and Et N (0.6 mL) afforded 1g (0.73 g, 90 % yield) as a colorless oil.
3
1
H NMR (400 MHz, CDCl ): δ = 7.78 (d, J = 2.4 Hz, 1 H), 7.43–7.35
3
8
(m, 4 H), 7.33–7.29 (m, 2 H), 6.98 (d, J = 8.8 Hz, 1 H), 3.91 (s, 2
13
time reported in Table 1, the reaction mixture was cooled to room
temperature and then passed through a pad of Celite. The filter
cake was washed with dichloromethane, and the combined filtrates
were concentrated under vacuum. The crude product was purified
by column chromatography (hexane/EtOAc, of varying ratios) on
silica gel to afford the pure product.
H) ppm. C NMR (100 MHz, CDCl ): δ = 169.1, 150.0, 138.7, 132.8,
3
1
1
32.2, 129.7, 129.5, 128.8, 127.6, 123.6, 90.7, 41.5 ppm. IR: ν˜ =
–
1
+
765 cm . HRMS (ESI): calcd. for C H O ClI [M + H] 372.9492;
14 11 2
found 372.9512.
1
-Iodo-2-naphthyl 2-Phenylacetate (9): 1-Iodo-2-naphthol (1 g,
3
.7 mmol), phenylacetyl chloride (0.86 g, 5.5 mmol), and Et N (1 mL)
3
1
3-Phenyl-4-(phenylethynyl)-2H-chromen-2-one (3a): 2-Iodo-
phenyl 2-phenylacetate (1a, 101 mg, 0.3 mmol), phenylacetylene
afforded 9 (1.3 g, 89 % yield) as a pale yellow solid; m.p. 80 °C. H
NMR (500 MHz, CDCl ): δ = 8.15 (d, J = 8.5 Hz, 1 H), 7.82–7.78 (m,
3
(
2a, 36 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and Et N
2
7
1
1
H), 7.60–7.57 (m, 1 H), 7.52–7.47 (m, 3 H), 7.41–7.38 (m, 2 H), 7.35–
2 3 2 3
1
3
(0.13 mL, 0.9 mmol) were stirred for 4 h to give 3a (87 mg, 91 %
.32 (m, 2 H), 4.02 (s, 2 H) ppm. C NMR (125 MHz, CDCl ): δ =
69.5, 150.1, 135.3, 133.1, 132.2, 132.1, 130.2, 129.8, 128.8, 128.4,
28.3, 127.6, 126.5, 121.4, 94.5, 41.7 ppm. IR (KBr): ν˜ = 1763 cm .
3
1
yield) as a white solid; m.p. 161 °C. H NMR (400 MHz, CDCl ): δ =
3
–
1
8.07 (dd, J = 8.4, 2 Hz, 1 H), 7.70–7.67 (m, 2 H), 7.60–7.55 (m, 1 H),
7.51–7.45 (m, 3 H), 7.40–7.32 (m, 7 H) ppm. 13C NMR (100 MHz,
+
HRMS (ESI): calcd. for C H O INa [M + Na] 410.9858; found
1
8 13 2
CDCl ): δ = 160.6, 152.9, 134.0, 133.1, 132.2, 131.8, 130.5, 130.4,
4
10.9883.
3
1
8
30.1, 129.0, 128.7, 127.9, 127.2, 124.6, 121.6, 119.1, 116.8, 104.8,
1
-Iodo-2-naphthyl Acetate (11):[14] 1-Iodonaphthalene-2-ol (1 g,
–1
3.7 ppm. IR (KBr): ν = 2207, 1711, 1596 cm . HRMS (ESI): calcd. for
˜
3
.7 mmol) was employed to give 11 (1.1 g, 95 % yield) as a yellow
+
C H O Na [M + Na] 345.0891; found 345.0920.
23 14 2
1
oil. H NMR (400 MHz, CDCl ): δ = 8.17 (dd, J = 8.4, 0.4 Hz, 1 H),
3
7
1
.84 (d, J = 8.8 Hz, 1 H), 7.80 (td, J = 8, 0.8 Hz, 1 H), 7.61–7.57 (m,
H), 7.53–7.49 (m, 1 H), 7.23 (d, J = 8.8 Hz, 1 H), 2.45 (s, 3 H) ppm.
3-(4-Methoxyphenyl)-4-(phenylethynyl)-2H-chromen-2-one
(3b): 2-Iodophenyl 2-(4-methoxyphenyl)acetate (1b, 110 mg,
1
3
C NMR (100 MHz, CDCl ): δ = 169.0, 150.1, 135.3, 132.2, 132.1,
0.3 mmol), phenylacetylene (2a, 36 μL, 0.33 mmol), PdCl
(PPh )
2 3 2
3
1
1
30.2, 128.4, 128.3, 126.5, 121.5, 94.6, 21.5 ppm. IR (KBr): ν˜ = (2 mg, 0.01 mmol), and Et
3
N (0.13 mL, 0.9 mmol) were stirred for
10 h to afford 3b (80 mg, 76 % yield) as a yellow solid; m.p. 186 °C.
–1
766 cm .
-Iodo-3,5-dimethylphenyl 2-Phenylacetate (13): 2-Iodo-3,5-di-
methylphenol (0.5 g, 2.0 mmol), phenylacetyl chloride (0.46 g,
1
H NMR (400 MHz, CDCl ): δ = 8.06 (dd, J = 8, 1.6 Hz, 1 H), 7.68 and
3
2
7
(
.02 (AA′BB′ pattern, J = 8.8 Hz, 4 H), 7.58–7.53 (m, 1 H), 7.45–7.34
m, 7 H), 3.88 (s, 3 H) ppm. 13C NMR (100 MHz, CDCl ): δ = 160.2,
3
3
.0 mmol), and Et N (0.6 mL) afforded 13 (0.68 g, 93 % yield) as a
colorless oil. H NMR (400 MHz, CDCl ): δ = 7.44–7.42 (m, 2 H), 7.39–
.35 (m, 2 H), 7.33–7.31 (m, 1 H), 6.94 (d, J = 0.8 Hz, 1 H), 6.68 (s, 1
H), 3.93 (s, 2 H), 2.43 (s, 3 H), 2.26 (s, 3 H) ppm. C NMR (100 MHz,
3
1
1
52.7, 132.2, 132.0, 131.5, 130.0, 129.9, 128.77, 128.74, 127.1, 126.3,
24.5, 121.7, 119.3, 116.7, 113.4, 104.4, 84.0, 76.9 (merged with
1
3
7
–1
CDCl signals), 55.5 ppm. IR (KBr): ν˜ = 2205, 1719, 1606 cm . HRMS
1
3
3
+
(ESI): calcd. for C H O Na [M + Na] 375.0997; found 375.0981.
24 16 3
CDCl ): δ = 169.5, 151.2, 143.3, 139.1, 133.3, 129.8, 128.7, 128.4,
3
–
1
1
(
27.4, 120.7, 93.2, 41.6, 28.4, 20.86 ppm. IR: ν˜ = 1762 cm . HRMS 3-(4-Bromophenyl)-4-(phenylethynyl)-2H-chromen-2-one (3c):
+
ESI): calcd. for C H O I [M + H] 367.0195; found 367.0178.
2-Iodophenyl 2-(4-bromophenyl)acetate (1c, 125 mg, 0.3 mmol),
phenylacetylene (2a, 36 μL, 0.33 mmol), PdCl (PPh ) (2 mg,
1
6 16 2
2
3 2
3
,5-Dimethyl-2-(phenylethynyl)phenyl 2-Phenylacetate (14): 2-
0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for 3 h to
3
Iodo-3,5-dimethylphenyl 2-phenylacetate (13, 110 mg, 0.3 mmol),
phenylacetylene (36 μL, 0.33 mmol), PdCl (PPh ) (2 mg,
.01 mmol), and Et N (0.13 mL, 0.9 mmol) afforded 14 as a pale
yellow oil. H NMR (400 MHz, CDCl ): δ = 7.40–7.36 (m, 4 H), 7.32–
.31 (m, 3 H), 7.26–7.24 (m, 3 H), 6.93 (d, J = 0.4 Hz, 1 H), 6.74 (s, 1
H), 3.91 (s, 2 H), 2.46 (s, 3 H), 2.30 (S, 3 H) ppm. C NMR (100 MHz,
CDCl ): δ = 169.7, 151.5, 141.9, 139.4, 133.4, 132.6, 131.6, 129.5,
28.7, 128.4, 128.1, 127.3, 123.4, 120.1, 114.3, 97.5, 83.4, 41.3, 29.8,
afford 3c (114 mg, 95 % yield) as a pale yellow solid; m.p. 178 °C.
2
3 2
1
H NMR (500 MHz, CDCl ): δ = 8.06 (dd, J = 8, 1.5 Hz, 1 H), 7.63–
3
0
3
13
1
7.57 (m, 5 H), 7.43–7.37 (m, 7 H) ppm. C NMR (125 MHz, CDCl ):
δ = 160.3, 152.9, 133.2, 132.9, 132.27, 132.25, 132.1, 131.2, 130.3,
129.0, 128.8, 127.3, 124.7, 123.3, 121.4, 119.0, 116.9, 105.4, 83.4 ppm.
3
3
7
1
3
–
1
IR (KBr): ν˜ = 2201, 1714, 1592 cm . HRMS (ESI): calcd. for
3
+
C H O BrNa [M + Na] 422.9997; found 423.0016.
23 13 2
1
2
[
–
1
0.8 ppm. IR: ν = 2195, 1762 cm . HRMS (ESI): calcd. for C H O Na
M + Na] 363.1362; found 363.1365.
˜
24 20
2
3-(4-Nitrophenyl)-4-(phenylethynyl)-2H-chromen-2-one (3d): 2-
Iodophenyl 2-(4-nitrophenyl)acetate (1d, 115 mg, 0.3 mmol), phen-
ylacetylene (2a, 36 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol),
+
2
-Iodophenyl Acetate (4a):[15] 2-Iodophenol (1 g, 4.5 mmol) was
2
3 2
1
and Et N (0.13 mL, 0.9 mmol) were stirred for 6 h to afford 3d
employed to afford 4a (1.15 g, 96 % yield) as a colorless oil. H NMR
400 MHz, CDCl ): δ = 7.82 (d, J = 8 Hz, 1 H), 7.36 (t, J = 7.2 Hz, 1
3
1
(77 mg, 70 % yield) as a pale yellow solid; m.p. 241 °C. H NMR
(
3
(400 MHz, CDCl ): δ = 8.35 and 7.89 (AA′BB′ pattern, J = 9.2, 8.8 Hz,
H), 7.10 (d, J = 8 Hz, 1 H), 6.97 (t, J = 7.6 Hz, 1 H), 2.36 (s, 3 H) ppm.
3
1
3
4 H), 8.08 (dd, J = 8.4, 1.6 Hz, 1 H), 7.66–7.62 (m, 1 H), 7.46–7.38 (m,
7
C NMR (100 MHz, CDCl ): δ = 168.7, 151.3, 139.5, 129.5, 127.7,
3
H) ppm. 13C NMR (100 MHz, CDCl ): δ = 159.9, 153.1, 147.9, 140.8,
1
23.1, 90.6, 21.3 ppm.
3
134.5, 132.8, 132.2, 131.8, 130.7, 128.9, 127.6, 125.0, 123.1, 120.9,
4
-tert-Butyl-2-iodophenyl Acetate (4b):[16] 4-tert-Butyl-2-iodo-
1
18.8, 117.0, 106.4, 82.9, 77.3 ppm. IR (KBr): ν˜ = 2199, 1709,
phenol (1 g, 3.6 mmol) was employed to afford 4b (1.062 g, 92 %
yield) as a colorless oil. H NMR (400 MHz, CDCl ): δ = 7.79 (d, J =
.4 Hz, 1 H), 7.36 (dd, J = 8.4, 2.4 Hz, 1 H), 7.00 (d, J = 8.4 Hz, 1 H),
.35 (s, 3 H), 1.30 (s, 9 H) ppm. C NMR (100 MHz, CDCl ): δ = 168.9,
–
1
+
1595 cm . HRMS (ESI): calcd. for C H NO Na [M + Na] 390.0742;
1
23 13 4
3
found 390.0770.
2
2
1
1
3
6-tert-Butyl-3-phenyl-4-(phenylethynyl)-2H-chromen-2-one
(3e): 4-tert-Butyl-2-iodophenyl 2-phenylacetate (1e, 118 mg,
3
51.0, 148.9, 136.5, 126.7, 122.3, 90.3, 34.5, 31.4, 21.3 ppm.
Eur. J. Org. Chem. 0000, 0–0
www.eurjoc.org
5
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
0
.3 mmol), phenylacetylene (2a, 36 μL, 0.33 mmol), PdCl (PPh )
4-ethynyltoluene (2b, 42 μL, 0.33 mmol), PdCl (PPh ) (2 mg,
2
3 2
2
3 2
(
2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for
h to afford 3e (102 mg, 90 % yield) as a white solid; m.p. 167 °C. afford 3j (105 mg, 89 % yield) as a white solid; m.p. 186 °C. H NMR
0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for 5 h to
3
3
1
4
1
H NMR (500 MHz, CDCl ): δ = 8.08 (d, J = 2.5 Hz, 1 H), 7.69–7.67
(400 MHz, CDCl ): δ = 8.07 (d, J = 2.4 Hz, 1 H), 7.69–7.66 (m, 2 H),
3
3
(
(
1
1
m, 2 H), 7.62 (dd, J = 8.5, 2 Hz, 1 H), 7.51–7.45 (m, 3 H), 7.41–7.32
7.61 (dd, J = 8.8, 2.4 Hz, 1 H), 7.50–7.43 (m, 3 H), 7.31 (d, J = 8.8 Hz,
1 H), 7.27–7.25 (m, 2 H), 7.16 (dd, J = 8.4, 0.4 Hz, 2 H), 2.37 (s, 3 H),
1
3
m, 6 H), 1.42 (s, 9 H) ppm. C NMR (125 MHz, CDCl ): δ = 160.9,
3
51.0, 147.6, 134.2, 133.4, 132.2, 130.5, 130.1, 130.0, 129.6, 128.9, 1.42 (s, 9 H) ppm. 13C NMR (100 MHz, CDCl ): δ = 161.0, 150.9, 147.5,
3
28.7, 127.9, 123.4, 121.7, 118.4, 116.4, 104.8, 83.9, 34.8, 31.5 ppm.
140.7, 134.2, 133.6, 132.1, 130.58, 130.50, 130.4, 129.5, 128.8, 127.9,
123.4, 118.6, 118.4, 116.3, 105.4, 83.5, 34.8, 31.5, 21.8 ppm. IR (KBr):
–
1
IR (KBr): ν = 2201, 1713, 1594 cm . HRMS (ESI): calcd. for
C H O Na [M + Na] 401.1517; found 401.1531.
˜
+
–1
+
ν˜ = 2203, 1714, 1595 cm . HRMS (ESI): calcd. for C H O [M + H]
27
22
2
28 25 2
3
93.1855; found 393.1861.
3
2
1
-(4-Bromophenyl)-6-tert-butyl-4-(phenylethynyl)-2H-chromen-
-one (3f): 4-tert-Butyl-2-iodophenyl 2-(4-bromophenyl)acetate (1f,
42 mg, 0.3 mmol), phenylacetylene (2a, 36 μL, 0.33 mmol),
3-(4-Bromophenyl)-6-tert-butyl-4-(p-tolylethynyl)-2H-chromen-
2-one (3k): 4-tert-Butyl-2-iodophenyl 2-(4-bromophenyl)acetate (1f,
142 mg, 0.3 mmol), 4-ethynyltoluene (2b, 42 μL, 0.33 mmol),
PdCl (PPh ) (2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were
stirred for 3 h to afford 3f (102 mg, 92 % yield) as a white solid;
m.p. 193 °C. H NMR (400 MHz, CDCl ): δ = 8.08 (d, J = 2.4 Hz, 1 H),
2
3 2
3
PdCl (PPh ) (2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were
2
3 2
3
1
stirred for 4 h to afford 3k (127 mg, 90 % yield) as a white solid;
3
1
m.p. 218 °C. H NMR (400 MHz, CDCl ): δ = 8.06 (d, J = 2 Hz, 1 H),
7
(
.65–7.56 (m, 5 H), 7.46–7.38 (m, 5 H), 7.32 (d, J = 8.4 Hz, 1 H), 1.42
3
s, 9 H) ppm. 1 C NMR (100 MHz, CDCl ): δ = 160.6, 150.9, 147.8,
3
7.64–7.56 (m, 5 H), 7.33–7.29 (m, 3 H), 7.20 (d, J = 7.6 Hz, 2 H), 2.39
3
(
s, 3 H), 1.42 (s, 9 H) ppm. 13C NMR (100 MHz, CDCl ): δ = 160.7,
1
1
2
33.6, 133.1, 132.29, 132.22, 131.1, 130.3, 129.8, 128.9, 128.6, 123.4,
3
150.9, 147.7, 141.0, 133.8, 133.1, 132.3, 132.1, 131.1, 129.8, 129.6,
23.2, 121.5, 118.3, 116.4, 105.4, 83.6, 34.8, 31.5 ppm. IR (KBr): ν =
˜
–
1
128.1, 123.5, 123.1, 118.4, 116.4, 106.0, 83.2, 34.8, 31.5, 21.8 ppm. IR
209, 1703, 1596 cm . HRMS (ESI): calcd. for C H O BrNa [M +
2
7 21 2
–
1
+
(KBr): ν = 2202, 1707, 1593 cm . HRMS (ESI): calcd. for C H O BrK
28 23 2
[
Na] 479.0623; found 479.0651.
˜
+
M + K] 509.0518; found 509.0547.
3
-Phenyl-4-(p-tolylethynyl)-2H-chromen-2-one (3g): 2-Iodo-
3
-Phenyl-4-(o-tolylethynyl)-2H-chromen-2-one (3l): 2-Iodo-
phenyl 2-phenylacetate (1a, 101 mg, 0.3 mmol), 4-ethynyltoluene
phenyl 2-phenylacetate (1a, 101 mg, 0.3 mmol), 2-ethynyltoluene
2c, 42 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and Et N
(2b, 42 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and Et N
2 3 2 3
(
2
3 2
3
(
0.13 mL, 0.9 mmol) were stirred for 4 h to afford 3g (91 mg, 90 %
1
(0.13 mL, 0.9 mmol) were stirred for 5 h to afford 3l (86 mg, 86 %
yield) as a white solid; m.p. 165 °C. H NMR (400 MHz, CDCl ): δ =
8
7
3
1
yield) as a white solid; m.p. 176 °C. H NMR (400 MHz, CDCl ): δ =
3
.06 (dd, J = 8, 1.6 Hz, 1 H), 7.69–7.66 (m, 2 H), 7.59–7.54 (m, 1 H),
8
.08 (dd, J = 8.4, 1.6 Hz, 1 H), 7.64–7.56 (m, 3 H), 7.49–7.36 (m, 6 H),
.50–7.41 (m, 3 H), 7.39–7.35 (m, 2 H), 7.27–7.25 (m, 2 H), 7.16–7.14
1
3
1
3
7.31–7.27 (m, 1 H), 7.20–7.15 (m, 2 H), 2.22 (s, 3 H) ppm. C NMR
100 MHz, CDCl ): δ = 160.7, 152.9, 141.2, 134.3, 133.5, 132.9, 131.8,
(m, 2 H), 1.36 (s, 3 H) ppm. C NMR (100 MHz, CDCl ): δ = 160.7,
3
(
3
1
1
52.9, 140.7, 134.1, 133.3, 132.1, 131.8, 130.5, 129.5, 128.9, 127.9,
27.3, 124.5, 119.2, 118.5, 116.7, 105.4, 83.4, 77.3, 21.8 ppm. IR (KBr):
1
30.3, 130.2, 129.8, 128.9, 128.2, 127.2, 125.9, 124.6, 121.4, 119.2,
116.8, 104.1, 87.2, 76.8 (merged with CDCl signals), 20.6 ppm. IR
[M
–
1
3
ν˜ = 2201, 1722, 1593 cm . HRMS (ESI): calcd. for C H O Na [M +
2
4 16 2
–
1
+
(KBr): ν˜ = 2197, 1720, 1592 cm . HRMS (ESI): calcd. for C24
H O
17 2
Na] 359.1048; found 359.1021.
+
+
H] 337.1229; found 337.1222.
3
-(4-Methoxyphenyl)-4-(p-tolylethynyl)-2H-chromen-2-one
3
-(4-Bromophenyl)-4-(o-tolylethynyl)-2H-chromen-2-one (3m):
(
0
3h): 2-Iodophenyl 2-(4-methoxyphenyl)acetate (1b, 110 mg,
.3 mmol), 4-ethynyltoluene (2b, 42 μL, 0.33 mmol), PdCl (PPh3)2
2-Iodophenyl 2-(4-bromophenyl)acetate (1c, 125 mg, 0.3 mmol), 2-
2
ethynyltoluene (2c, 42 μL, 0.33 mmol), PdCl (PPh ) (2 mg,
2
3 2
(2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for
3
0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for 5 h to
3
1
0 h to afford 3h (78 mg, 71 % yield) as a white solid; m.p. 186 °C.
1
afford 3m (111 mg, 89 % yield) as a white solid; m.p. 216 °C.
NMR (400 MHz, CDCl ): δ = 8.07 (dd, J = 8.4, 1.6 Hz, 1 H), 7.61–7.52
H
1
H NMR (400 MHz, CDCl ): δ = 8.05 (d, J = 7.2 Hz, 1 H), 7.68–8.08
3
3
(d, J = 8.8 Hz, 2 H), 7.55–8.08 (t, J = 6.8 Hz, 1 H), 7.38–7.32 (m, 4 H),
(m, 5 H), 7.41–7.37 (m, 3 H), 7.32 (t, J = 7.6 Hz, 1 H), 7.23–7.18 (m,
7
(
.17 (d, J = 7.6 Hz, 2 H), 7.01 (d, J = 8.4 Hz, 2 H), 3.88 (s, 3 H), 2.38
13
2
1
1
H), 2.26 (s, 3 H) ppm. C NMR (100 MHz, CDCl ): δ = 160.4, 153.0,
3
s, 3 H) ppm. 13C NMR (100 MHz, CDCl ): δ = 160.1, 152.7, 140.6,
3
41.2, 133.7, 133.2, 132.9, 132.1, 131.4, 130.4, 130.0, 128.9, 127.3,
26.0, 124.7, 123.2, 121.2, 119.1, 116.9, 104.7, 86.9, 77.3, 20.6 ppm.
1
1
1
3
32.3, 132.1, 132.0, 131.5, 129.5, 127.2, 126.3, 124.5, 119.3, 118.6,
16.7, 113.3, 105.0, 83.6, 77.3, 55.5, 21.8 ppm. IR (KBr): ν = 2201,
˜
–1
IR (KBr): ν˜ = 2195, 1719, 1593 cm . HRMS (ESI): calcd. for C H O Br
24 16 2
720, 1593 cm–1. HRMS (ESI): calcd. for C25H18O Na [M + Na]
+
3
+
[
M + H] 415.0334; found 415.0338.
89.1154; found 389.1171.
3
-(4-Nitrophenyl)-4-(o-tolylethynyl)-2H-chromen-2-one (3n): 2-
3
-(4-Bromophenyl)-4-(p-tolylethynyl)-2H-chromen-2-one (3i): 2-
Iodophenyl 2-(4-bromophenyl)acetate (1c, 125 mg, 0.3 mmol), 4-
ethynyltoluene (2b, 42 μL, 0.33 mmol), PdCl (PPh ) (2 mg,
Iodophenyl 2-(4-nitrophenyl)acetate (1d, 115 mg, 0.3 mmol), 2-eth-
ynyltoluene (2c, 42 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol),
and Et N (0.13 mL, 0.9 mmol) were stirred for 6 h to afford 3n
(85 mg, 74 % yield) as a white solid; m.p. 253 °C. H NMR (400 MHz,
CDCl ): δ = 8.34 and 7.85 (AA′BB′ pattern, J = 9.2, 9.2 Hz, 4 H), 8.10
(dd, J = 8, 1.6 Hz, 1 H), 7.66–7.62 (m, 1 H), 7.44–7.41 (m, 2 H), 7.36–
7
(100 MHz, CDCl ): δ = 160.0, 153.1, 147.9, 141.1, 141.0, 134.8, 132.9,
2
3 2
2
3 2
3
0
.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for 4 h to
1
3
1
afford 3i (113 mg, 91 % yield) as a white solid; m.p. 201 °C. H NMR
3
(400 MHz, CDCl ): δ = 8.06 (dd, J = 8.4, 1.6 Hz, 1 H), 7.63–7.56 (m,
3
5
H), 7.40–7.36 (m, 2 H), 7.30 (d, J = 8 Hz, 2 H), 7.19 (d, J = 8 Hz, 2
13
.31 (m, 2 H), 7.23–7.18 (m, 2 H), 2.26 (s, 3 H) ppm. C NMR
1
3
H), 2.39 (s, 3 H) ppm. C NMR (100 MHz, CDCl ): δ = 160.4, 152.9,
3
3
1
1
2
41.0, 133.5, 133.0, 132.2, 132.1, 132.19, 131.10, 129.6, 128.5, 127.4,
1
1
32.7, 131.7, 130.8, 130.1, 127.6, 127.5, 126.2, 125.0, 123.3, 120.8,
24.7, 123.2, 119.0, 118.3, 116.8, 106.0, 83.1, 21.8 ppm. IR (KBr): ν˜ =
18.8, 117.1, 105.7, 86.4, 20.7 ppm. IR (KBr): ν = 2192, 1714,
˜
–
1
205, 1721, 1593 cm . HRMS (ESI): calcd. for C H O BrNa [M +
–1
+
2
4
15
2
1595 cm . HRMS (ESI): calcd. for C H O NK [M + K] 420.0638;
found 420.0638.
24 15 4
+
Na] 437.0153; found 437.0136.
6
-tert-Butyl-3-phenyl-4-(p-tolylethynyl)-2H-chromen-2-one (3j):
3-(4-Bromophenyl)-6-tert-butyl-4-(o-tolylethynyl)-2H-chromen-
2-one (3o): 4-tert-Butyl-2-iodophenyl 2-(4-bromophenyl)acetate (1f,
4
-tert-Butyl-2-iodophenyl 2-phenylacetate (1e, 118 mg, 0.3 mmol),
Eur. J. Org. Chem. 0000, 0–0
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1
42 mg, 0.3 mmol), 2-ethynyltoluene (2c, 42 μL, 0.33 mmol),
0.3 mmol), 4-ethynylanisole (2e, 43 μL, 0.33 mmol), PdCl (PPh )
2
3 2
PdCl (PPh ) (2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were (2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for
2
3 2
3
3
stirred for 4 h to afford 3o (121 mg, 86 % yield) as a white solid;
8 h to afford 3t (89 mg, 75 % yield) as a yellow solid; m.p. 276 °C.
1
1
m.p. 203 °C. H NMR (400 MHz, CDCl ): δ = 8.09 (d, J = 2 Hz, 1 H),
H NMR (500 MHz, CDCl ): δ = 8.35, 7.89, 7.33 and 6.90 (AA′BB′
3
3
7
.65–7.59 (m, 3 H), 7.54–7.51 (m, 2 H), 7.34–7.30 (m, 3 H), 7.25–7.19 pattern, J = 8.5, 9, 8.5, 8.5 Hz, 8 H), 8.08 (dd, J = 8.5, 1.5 Hz, 1 H),
1
3
13
(m, 2 H), 2.34 (s, 3 H), 1.41 (s, 9 H) ppm. C NMR (100 MHz, CDCl3):
δ = 160.6, 151.0, 147.8, 141.1, 134.1, 133.4, 132.9, 132.1, 131.3, 130.4,
7.64–7.61 (m, 1 H), 7.43–7.40 (m, 2 H), 3.84 (s, 3 H) ppm. C NMR
(125 MHz, CDCl ): δ = 161.6, 160.0, 153.1, 147.8, 141.0, 134.9, 134.1,
3
1
8
29.9, 129.8, 128.6, 126.1, 123.5, 123.1, 121.4, 118.3, 116.5, 104.6, 132.7, 131.8, 127.6, 126.8, 124.9, 123.1, 118.8, 117.0, 114.7, 112.9,
–
1
–1
7.2, 34.9, 31.5, 20.7 ppm. IR (KBr): ν = 2200, 1709, 1594 cm . HRMS 107.4, 82.5, 55.6 ppm. IR (KBr): ν = 2194, 1707, 1598 cm . HRMS
˜
˜
+
+
(ESI): calcd. for C H O BrK [M + K] 509.0518; found 509.0501.
(ESI): calcd. for C H O NK [M + K] 436.0587; found 436.0582.
28
23
2
24 15 5
4
-(Mesitylethynyl)-3-phenyl-2H-chromen-2-one (3p): 2-Iodo-
6-tert-Butyl-4-(4-methoxyphenylethynyl)-3-phenyl-2H-
phenyl 2-phenylacetate (1a, 101 mg, 0.3 mmol), mesitylacetylene chromen-2-one (3u): 4-tert-Butyl-2-iodophenyl 2-phenylacetate
(
2d, 52 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and Et N (1e, 118 mg, 0.3 mmol), 4-ethynylanisole (2e, 43 μL, 0.33 mmol),
2 3 2 3
(
0.13 mL, 0.9 mmol) were stirred for 6 h to afford 3p (88 mg, 81 %
PdCl (PPh ) (2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were
2 3 2 3
1
yield) as a white solid; m.p. 193 °C. H NMR (400 MHz, CDCl ): δ =
8
6
stirred for 10 h to afford 3u (86 mg, 70 % yield) as a pale yellow
3
1
.12 (dd, J = 8, 1.2 Hz, 1 H), 7.60–7.55 (m, 3 H), 7.46–7.35 (m, 5 H),
solid; m.p. 158 °C. H NMR (400 MHz, CDCl ): δ = 8.07 (d, J = 2 Hz,
3
.84 (d, J = 0.4 Hz, 2 H), 2.27 (s, 3 H), 2.18 (s, 6 H) ppm. 13C NMR
1 H), 7.69–7.67 (m, 2 H), 7.61 (dd, J = 8.8, 2.4 Hz, 1 H), 7.51–7.44 (m,
3 H), 7.33–7.30 (m, 3 H), 6.88 (AA′BB′ pattern, J = 8.8 Hz, 2 H), 3.83
(100 MHz, CDCl ): δ = 160.8, 153.0, 141.5, 140.2, 134.7, 134.1, 131.7,
3
1
1
30.1, 129.9, 128.8, 128.4, 128.0, 127.2, 124.5, 119.4, 118.5, 116.9, (s, 3 H), 1.42 (s, 9 H) ppm. 13C NMR (100 MHz, CDCl ): δ = 161.1,
3
–
1
03.5, 90.9, 21.5, 20.9 ppm. IR (KBr): ν = 2196, 1714, 1598 cm .
150.9, 147.5, 134.4, 133.9, 133.8, 130.5, 129.4, 129.0, 128.8, 127.9,
123.4, 118.4, 116.3, 114.4, 113.7, 105.7, 83.3, 77.3, 55.5, 34.8,
˜
+
HRMS (ESI): calcd. for C26H20O Na [M + Na] 387.1361; found
3
2
–
1
87.1374.
31.5 ppm. IR (KBr): ν˜ = 2198, 1709, 1596 cm . HRMS (ESI): calcd. for
+
C H O [M + H] 409.1804; found 409.1790.
2
8 25 3
6
-tert-Butyl-4-(mesitylethynyl)-3-phenyl-2H-chromen-2-one
(
0
3q): 4-tert-Butyl-2-iodophenyl 2-phenylacetate (1e, 118 mg,
.3 mmol), mesitylacetylene (2d, 52 μL, 0.33 mmol), PdCl (PPh3)2
3-(4-Bromophenyl)-6-tert-butyl-4-(4-methoxyphenylethynyl)-
2H-chromen-2-one (3v): 4-tert-Butyl-2-iodophenyl 2-(4-bromo-
phenyl)acetate (1f, 142 mg, 0.3 mmol), 4-ethynylanisole (2e, 43 μL,
0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and Et N (0.13 mL,
2
(2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for
3
6
h to afford 3q (113 mg, 90 % yield) as a white solid; m.p. 179 °C.
2
3 2
3
1
H NMR (400 MHz, CDCl ): δ = 8.12 (d, J = 2.4 Hz, 1 H), 7.63 (dd, J = 0.9 mmol) were stirred for 8 h to afford 3v (112 mg, 77 % yield) as
3
1
8
.8, 2.4 Hz, 1 H), 7.54–7.52 (m, 2 H), 7.46–7.40 (m, 3 H), 7.34 (d, J = a white solid; m.p. 203 °C. H NMR (400 MHz, CDCl ): δ = 8.06 (d,
3
8
.8 Hz, 1 H), 6.85 (s, 2 H), 2.28 (s, 3 H), 2.17 (s, 6 H), 1.40 (s, 9 H) ppm.
J = 2.4 Hz, 1 H), 7.64–7.56 (m, 5 H), 7.34 and 6.91 (AA′BB′ pattern,
J = 8.8, 8.8 Hz, 4 H), 7.31 (d, J = 8.8 Hz, 1 H), 3.85 (s, 3 H), 1.42 (s, 9
13
C NMR (100 MHz, CDCl ): δ = 161.1, 151.0, 147.6, 140.1, 134.9,
3
1
1
3
34.5, 130.1, 129.9, 129.4, 128.7, 128.48, 128.44, 123.6, 118.67,
H) ppm. 13C NMR (100 MHz, CDCl ): δ = 161.3, 160.7, 150.9, 147.6,
3
18.64, 116.4, 103.4, 91.1, 76.8 (merged with CDCl3 signals), 34.9, 133.9, 133.3, 132.3, 131.1, 129.7, 127.6, 123.4, 123.0, 118.3, 116.8,
–
1
1.6, 21.5, 20.9 ppm. IR (KBr): ν = 2188, 1719, 1595 cm . HRMS
116.4, 114.6, 113.4, 106.3, 83.0, 55.5, 34.8, 31.5 ppm. IR (KBr): ν =
˜
˜
+
–1
+
(ESI): calcd. for C H O [M + H] 421.2168; found 421.2198.
2195, 1699, 1595 cm . HRMS (ESI): calcd. for C H O Br [M + H]
30
29
2
28 25 3
487.0909; found 487.0915.
4
-(4-Methoxyphenylethynyl)-3-phenyl-2H-chromen-2-one (3r):
2
-Iodophenyl 2-phenylacetate (1a, 101 mg, 0.3 mmol), 4-ethynyl-
6-Chloro-3-phenyl-4-(phenylethynyl)-2H-chromen-2-one (3y): 4-
chloro-2-iodophenyl 2-phenylacetate (1g, 110 mg, 0.3 mmol), phen-
anisole (2e, 43 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and
2
3 2
Et N (0.13 mL, 0.9 mmol) were stirred for 8 h to afford 3r (83 mg, ylacetylene (36 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and
3
2
3 2
1
7
9 % yield) as a yellow solid; m.p. 118 °C. H NMR (400 MHz, CDCl ):
δ = 8.06 (dd, J = 8, 1.6 Hz, 1 H), 7.69–7.67 (m, 2 H), 7.59–7.55 (m, 1
H), 7.49–7.45 (m, 2 H), 7.39–7.35 (m, 3 H), 7.31 and 6.86 (AA′BB′
Et N (0.13 mL, 0.9 mmol) were stirred for 5 h to afford 3y (90 mg,
87 % yield) as a pale yellow solid; m.p. 159 °C. H NMR (400 MHz,
3
3
1
CDCl ): δ = 8.01 (d, J = 2.8 Hz, 1 H), 7.68–7.66 (m, 2 H), 7.53–7.46
3
1
3
13
pattern, J = 8.8, 9.2 Hz, 4 H), 3.83 (s, 3 H) ppm. C NMR (100 MHz,
(m, 4 H), 7.42–7.32 (m, 6 H) ppm. C NMR (125 MHz, CDCl ): δ =
3
CDCl ): δ = 161.1, 152.9, 135.3, 134.2, 134.0, 131.8, 130.5, 129.4,
160.0, 151.3, 133.7, 132.3, 131.9, 131.8, 131.2, 130.4, 130.3, 130.0,
3
1
5
28.9, 127.9, 127.3, 124.5, 119.2, 116.8, 114.4, 113.6, 105.9, 83.1, 77.3, 129.3, 128.7, 128.0, 126.7, 121.3, 120.3, 118.2, 105.4, 83.2 ppm. IR
–
1
–1
5.5 ppm. IR (KBr): ν˜ = 2198, 1719, 1598 cm . HRMS (ESI): calcd. for (KBr): ν˜ = 2203, 1722, 1266 cm . HRMS (ESI): calcd. for C H O Cl
23 14 2
+
+
C H O Na [M + Na] 375.0997; found 375.1006.
[M + H] 357.0682; found 357.0675.
24 16 3
3
2
-(4-Bromophenyl)-4-(4-methoxyphenylethynyl)-2H-chromen-
-one (3s): 2-Iodophenyl 2-(4-bromophenyl)acetate (1c, 125 mg,
3-Phenyl-4-[(trimethylsilyl)ethynyl]-2H-chromen-2-one (3w): 2-
Iodophenyl 2-phenylacetate (1a, 101 mg, 0.3 mmol), trimethylsilyl-
acetylene (2f, 0.17 mL, 1.2 mmol), PdCl (PPh ) (2 mg, 0.01 mmol),
0
.3 mmol), 4-ethynylanisole (2e, 43 μL, 0.33 mmol), PdCl (PPh3)2
2
2
3 2
(
8
2
2 mg, 0.01 mmol), and Et N (0.13 mL, 0.9 mmol) were stirred for
and Et N (0.13 mL, 0.9 mmol) were stirred for 12 h to afford 3w
(74 mg, 78 % yield) as a white solid; m.p. 99 °C. H NMR (400 MHz,
3
3
1
h to afford 3s (101 mg, 82 % yield) as a pale yellow solid; m.p.
1
06 °C. H NMR (400 MHz, CDCl ): δ = 8.05 (dd, J = 8.4, 1.6 Hz, 1
CDCl ): δ = 7.95 (dd, J = 8.4, 1.6 Hz, 1 H), 7.62–7.59 (m, 2 H), 7.57–
3
3
H), 7.63–7.56 (m, 5 H), 7.40–7.34 (m, 4 H), 6.90 (AA′BB′ pattern, J = 7.53 (m, 1 H), 7.46–7.40 (m, 3 H), 7.36–7.32 (m, 2 H), 0.176 (s, 9
1
3
13
8
1
1
.8 Hz, 2 H), 3.84 (s, 3 H) ppm. C NMR (400 MHz, CDCl ): δ = 161.3,
H) ppm. C NMR (100 MHz, CDCl ): δ = 160.6, 152.9, 133.7, 132.7,
3
3
52.9, 134.0, 133.6, 133.1, 132.3, 132.0, 131.1, 128.0, 127.3, 124.6, 131.8, 131.4, 130.3, 128.9, 127.8, 127.4, 124.6, 119.0, 116.6, 112.6,
23.1, 119.0, 116.8, 114.5, 113.3, 106.3, 82.8, 76.8 (merged with
–
1
98.0, –0.5 ppm. IR (KBr): ν˜ = 1712, 1401 cm . HRMS (ESI): calcd. for
–
1
+
CDCl signals), 55.5 ppm. IR (KBr): ν˜ = 2197, 1721, 1593 cm . HRMS
C H O Na [M + Na] 341.0974; found 341.0991.
3
20 18 2
+
(
ESI): calcd. for C H O Br [M + H] 431.0283; found 431.0312.
24 16 3
4
-Ethynyl-3-phenyl-2H-chromen-2-one (3x): Tetra-n-butylammo-
4
-(4-Methoxyphenylethynyl)-3-(4-nitrophenyl)-2H-chromen-2-
nium fluoride (1 in THF, 0.2 mL, 0.69 mmol) was added to a
M
one (3t): 2-Iodophenyl 2-(4-nitrophenyl)acetate (1d, 115 mg,
solution of 3-phenyl-4-[(trimethylsilyl)ethynyl]-2H-chromen-2-one
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(3w, 200 mg, 0.62 mmol) in THF (8 mL) under anhydrous conditions
4-tert-Butyl-2-(3-phenylpropynoyl)phenyl Acetate (5b): 4-tert-
at 0 °C, and the resulting mixture was stirred at room temperature Butyl-2-iodophenyl acetate (4b, 96 mg, 0.3 mmol), phenylacetylene
for 10 min. The solvent was removed under reduced pressure, and
the residue was then dissolved in EtOAc. The solution was washed
with brine, and the organic layer was dried with Na SO and con-
(2a, 36 μL, 0.33 mmol), PdCl (PPh ) (2 mg, 0.01 mmol), and Et N
2 3 2 3
(0.13 mL, 0.9 mmol) were combined to afford 5b (95 mg, 99 % yield)
as a pale yellow oil. 1H NMR (400 MHz, CDCl ): δ = 8.29 (d, J =
2
4
3
centrated under reduced pressure. The crude product was purified
2.4 Hz, 1 H), 7.65–7.62 (m, 3 H), 7.50–7.46 (m, 1 H), 7.43–7.39 (m,
1
3
by flash chromatography (EtOAc/hexane, 10:90 v/v) on silica gel to H), 7.06 (d, J = 8 Hz, 1 H), 2.33 (s, 3 H), 1.38 (s, 9 H) ppm. C NMR
1
give 3x (124 mg, 80 % yield) as a pale pink solid; m.p. 166 °C. H
(100 MHz, CDCl ): δ = 176.5, 169.9, 149.2, 147.9, 133.2, 132.0, 131.0,
3
NMR (400 MHz, CDCl ): δ = 7.98 (d, J = 8 Hz, 1 H), 7.60–7.55 (m, 3
130.1, 128.9, 123.6, 120.2, 92.6, 87.9, 77.1 (merged with CDCl sig-
3
3
13
–1
H), 7.46–7.41 (m, 3 H), 7.37–7.34 (m, 2 H), 3.69 (s, 1 H) ppm.
C
nals), 34.8, 31.3, 21.2 ppm. IR: ν˜ = 2197, 1764, 1644 cm . HRMS
+
NMR (100 MHz, CDCl ): δ = 160.3, 152.8, 133.5, 132.3, 132.0, 131.9,
(ESI): calcd. for C H O Na [M + Na] 343.1310; found 343.1332.
3
21 20 3
1
30.2, 129.2, 128.1, 127.2, 124.7, 119.0, 116.7, 92.4, 77.1 (merged
General Procedure for Carbonylative Annulation Reaction of 2-
Iodoaryl Acetates in Triethylamine: To a Schlenk flask were added
PdCl (PPh ) (0.02 mmol) and triethylamine (10 mL). To this suspen-
–
1
with CDCl signals) ppm. IR (KBr): ν˜ = 2102, 1717, 1599 cm . HRMS
3
(ESI): calcd. for C H O Na [M + Na] 269.0578; found 269.0558.
17 10 2
2
3 2
sion was added 2-iodophenyl acetate (4a) or 4b (1 equiv.) followed
by addition of phenylacetylene (2a, 1.2 equiv.). The reaction mixture
was flushed with CO and then stirred under CO (1 atm, balloon) at
Procedure for One-Pot Synthesis of 3a and 3e: A mixture of the
corresponding 2-iodophenol (110 mg, 0.5 mmol) and Et N (0.2 mL,
3
1
.5 mmol) was placed in an oven-dried Schlenk tube under N , and
2
80 °C for 72 h. The progress of the reaction was monitored by
toluene (8 mL) was added followed by a solution of 2-phenylacetyl
chloride (93 mg, 0.6 mmol) in toluene (4 mL). The reaction mixture
was stirred at 25 °C for 30 min, and then phenylacetylene (60 μL,
TLC. Within 4 h, the starting materials were consumed, and the
carbonylative Sonogashira coupling product (5a or 5b) was formed,
as observed by the formation of a distinct spot on the TLC plate.
Upon a prolonged reaction time (72 h), a mixture of compounds
was formed. After cooling the reaction mixture to room tempera-
ture, the solvent was evaporated. The residue was partitioned be-
tween brine and CH Cl2 and then extracted with CH Cl . The or-
0
.55 mmol) and PdCl (PPh ) (4 mg, 1 mol-%) were added. The re-
2 3 2
sulting mixture was flushed with CO and then stirred under CO
(
(
1 atm, balloon) at 80 °C for 6 or 8 h to give 3a or 3e, respectively
Scheme 3). The mixture was cooled to room temperature and fil-
tered through a pad of Celite. The filter cake was washed with di-
chloromethane several times. The combined filtrates were concen-
trated under vacuum. The crude product was purified by column
chromatography (hexane/EtOAc, 9.7:0.3 v/v) on silica gel to afford
the corresponding pure product [3a (72 % yield), 3e (77 % yield)].
2
2
2
ganic layer was concentrated under vacuum, and crude mixture
was purified by column chromatography on silica gel (CH Cl /hex-
2
2
ane, 10:1 v/v) to give 6a and 7a and (EtOAc/hexane, 1:30 v/v) to
give 6b, 7b, and 8b.
2
5
6
-Iodophenyl acetate (4a, 105 mg, 0.4 mmol), phenylacetylene (2a,
2
-Naphthyl 2-Phenylacetate (10): 1-Iodo-2-naphthyl 2-phenyl-
3 μL, 0.48 mmol), and PdCl (PPh ) (5.6 mg, 0.02 mmol) afforded
2
3 2
acetate (9, 116 mg, 0.3 mmol), phenylacetylene (2a, 36 μL,
a and 7a.
0
0
.33 mmol), PdCl (PPh3)2 (2 mg, 0.01 mmol), and Et N (0.13 mL,
2 3
.9 mmol) were stirred for 5 h to give 10 (75 mg, 96 % yield) as a
[
12]
3-Acetyl-2-phenyl-4H-chromen-4-one (6a): White solid (29 mg,
1
1
27 % yield); m.p. 109 °C. H NMR (400 MHz, CDCl ): δ = 8.19–8.17
pale orange solid; m.p. 86 °C, H NMR (400 MHz, CDCl ): δ = 7.84
3
3
(
7
m, 1 H), 7.93–7.90 (m, 2 H), 7.73–7.68 (m, 1 H), 7.61–7.56 (m, 1 H),
.49–7.40 (m, 4 H), 2.38 (s, 3 H) ppm. 13C NMR (100 MHz, CDCl3):
δ = 175.9, 165.5, 156.1, 137.1, 134.2, 133.9, 129.5, 128.89, 128.85,
26.1, 125.6, 123.5, 123.2, 117.9, 19.2 ppm. IR (KBr): ν = 1675, 1641,
(d, J = 9.2 Hz, 2 H), 7.83–7.79 (m, 1 H), 7.57 (d, J = 2.4 Hz, 1 H),
7
3
1
1
.51–7.40 (m, 6 H), 7.37–7.33 (m, 1 H), 7.22 (dd, J = 8.8, 2.4 Hz, 1 H),
.94 (s, 2 H) ppm. 13C NMR (100 MHz, CDCl ): δ = 170.2, 148.4, 133.8,
3
1
33.5, 131.5, 129.4, 128.8, 127.8, 127.7, 127.5, 126.6, 125.8, 121.1,
18.5, 41.6 ppm. IR (KBr): ν˜ = 1757 cm . HRMS (ESI): calcd. for
˜
+
–
1
–
1
1575 cm . HRMS (ESI): calcd. for C H O [M + H] 265.0865; found
265.0862.
17 13
3
+
C H O Na [M + Na] 285.0891; found 285.0918.
18 14 2
[
17]
2
-Phenyl-4H-chromen-4-one (7a):
White solid (37 mg, 42 %
1
-(Phenylethynyl)-2-naphthyl Acetate (12): 1-Iodo-2-naphthyl
1
yield); m.p. 83 °C. H NMR (400 MHz, CDCl ): δ = 8.23 (dd, J = 8,
3
acetate (11, 94 mg, 0.3 mmol), phenylacetylene (2a, 36 μL,
1.6 Hz, 1 H), 7.94–7.91 (m, 2 H), 7.72–7.68 (m, 1 H), 7.58–7.49 (m, 4
0
0
.33 mmol), PdCl (PPh3)2 (2 mg, 0.01 mmol), and Et N (0.13 mL,
2 3
.9 mmol) were stirred for 5 h to afford 12 (84 mg, 98 % yield) as a
13
H), 7.44–7.40 (m, 1 H), 6.83 (s, 1 H) ppm. C NMR (100 MHz, CDCl3):
δ = 178.6, 163.5, 156.4, 133.9, 131.9, 131.7, 129.1, 126.4, 125.8, 125.3,
1
yellow solid; m.p. 97 °C. H NMR (400 MHz, CDCl ): δ = 8.41 (d, J =
3
–1
1
24.1, 118.2, 107.7 ppm. IR (KBr): ν˜ = 1645, 1603, 1563 cm . HRMS
8
.4 Hz, 1 H), 7.87–7.85 (m, 2 H), 7.64–7.60 (m, 3 H), 7.55–7.51 (m, 1
+
(ESI): calcd. for C H O Na [M + Na] 245.0578; found 245.0551.
15 10 2
H), 7.41–7.40 (m, 3 H), 7.29 (d, J = 8.8 Hz, 1 H), 2.45 (s, 3 H) ppm.
13
C NMR (100 MHz, CDCl ): δ = 169.2, 150.4, 133.8, 131.7, 131.4,
4-tert-Butyl-2-iodophenyl acetate (4b, 160 mg, 0.5 mmol), phenyl-
29.8, 128.8, 128.6, 128.3, 127.5, 126.35, 126.31, 123.2, 121.2, 113.3, acetylene (2a, 66 μL, 0.6 mmol), and PdCl (PPh (7 mg, 0.02 mmol)
3
1
9
2
)
3 2
–
1
9.5, 82.5, 21.1 ppm. IR (KBr): ν˜ = 2200, 1766 cm . HRMS (ESI):
afforded 6b, 7b, and 8b.
+
calcd. for C H O [M + H] 287.1072; found 287.1063.
20 15 2
3-Acetyl-6-tert-butyl-2-phenyl-4H-chromen-4-one (6b): White
solid (19 mg, 12 % yield); m.p. 116 °C. H NMR (400 MHz, CDCl
δ = 8.23 (d, J = 2.4 Hz, 1 H), 7.78 (dd, J = 8.8, 2.8 Hz, 1 H), 7.65–7.63
1
-(3-Phenylpropynoyl)phenyl Acetate (5a):[12a] 2-Iodophenyl
acetate (4a, 79 mg, 0.3 mmol), phenylacetylene (2a, 36 μL,
):
3
2
1
3
(
(
m, 2 H), 7.54–7.45 (m, 4 H), 2.46 (s, 3 H), 1.39 (s, 9 H) ppm. C NMR
100 MHz, CDCl ): δ = 200.8, 176.3, 162.5, 154.2, 149.2, 132.4, 132.1,
0
.33 mmol), PdCl (PPh3)2 (2 mg, 0.01 mmol), and Et N (0.13 mL,
2
3
3
0
.9 mmol) were combined to afford 5a (80 mg, 100 % yield) as a
1
131.5, 128.9, 128.7, 124.9, 122.9, 121.8, 117.8, 35.0, 32.4, 31.4 ppm.
yellow oil. H NMR (400 MHz, CDCl ): δ = 8.27 (dd, J = 8, 1.6 Hz, 1
H), 7.65–7.60 (m, 3 H), 7.49–7.46 (m, 1 H), 7.42–7.39 (m, 3 H), 7.14
3
–
1
IR (KBr): ν˜ = 1707, 1639, 1616 cm . HRMS (ESI): calcd. for C H O
2
1 21 3
+
1
3
[M + H] 321.1491; found 321.1508.
(dd, J = 8, 1.2 Hz, 1 H), 2.35 (s, 3 H) ppm. C NMR (100 MHz, CDCl3):
δ = 176.1, 169.7, 150.2, 134.8, 133.2, 133.1, 131.0, 129.6, 128.8, 126.2,
6-tert-Butyl-2-phenyl-4H-chromen-4-one (7b): White solid
–
1
1
1
24.1, 120.0, 92.7, 87.8, 21.2 ppm. IR: ν˜ = 2196, 1767 cm . HRMS (66 mg, 47 % yield); m.p. 126 °C. H NMR (400 MHz, CDCl ): δ = 8.22
3
+
(
ESI): calcd. for C H O [M + H] 265.0865; found 265.0844.
(d, J = 2.4 Hz, 1 H), 7.94–7.91 (m, 2 H), 7.76 (dd, J = 8.8, 2.8 Hz, 1
1
7 13 3
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H), 7.53–7.50 (m, 4 H), 6.83 (s, 1 H), 1.39 (s, 9 H) ppm. 13C NMR
100 MHz, CDCl ): δ = 178.9, 163.3, 154.6, 148.7, 132.0, 131.8, 131.6,
Symeonidis, M. Chamilos, D. J. Hadjipavlou-Litina, M. Kallitsakis, K. E. Liti-
nas, Bioorg. Med. Chem. Lett. 2009, 19, 1139–1142.
3] a) K. Hara, T. Sato, R. Katoh, A. Furube, A. Ohga, A. Shinpo, S. Suga, K.
Sayama, H. Sugihara, H. Arakawa, J. Phys. Chem. B 2003, 107, 597–606;
b) H. N. Ghosh, J. B. Asbury, T. Lian, J. Phys. Chem. B 1998, 102, 6482–
(
3
[
[
1
1
3
29.1, 126.4, 123.4, 121.6, 117.8, 107.6, 35.0, 31.4 ppm. IR (KBr): ν =
˜
–1
+
652, 1615 cm . HRMS (ESI): calcd. for C H O Na [M + Na]
1
9 18 2
01.1204; found 301.1176.
6
486; c) J. M. Rehm, G. L. McLendon, Y. Nagasawa, K. Yoshihara, J. Moser,
M. Grätzel, J. Phys. Chem. 1996, 100, 9577–9578; d) G. Ramakrishna, H. N.
Ghosh, J. Phys. Chem. A 2002, 106, 2545–2553.
4] a) J. R. Johnson, Org. React. 1942, 1, 210–265; b) T. Rosen, in: Comprehen-
sive Organic Synthesis (Eds.: B. M. Trost, I. Fleming), Pergamon Press, Ox-
ford, UK, 1991, vol. 2, p. 395–408.
[5] a) S. Sethna, R. Phadke, Org. React. 1953, 7, 1–58; b) M. S. Holden, R. D.
Crouch, J. Chem. Educ. 1998, 75, 1631.
[6] X.-G. Liu, S.-S. Zhang, C.-Y. Jiang, J.-Q. Wu, Q. Li, H. Wang, Org. Lett. 2015,
17, 5404–5407.
(
Z)-2-Benzylidene-5-tert-butylbenzofuran-3(2H)-one (8b): White
1
solid (48 mg, 34 % yield); m.p. 121 °C. H NMR (400 MHz, CDCl ):
3
δ = 7.93–7.91 (m, 2 H), 7.81 (d, J = 2 Hz, 1 H), 7.72 (dd, J = 8.4,
2
.0 Hz, 1 H), 7.48–7.37 (m, 3 H), 7.26 (d, J = 8.8 Hz, 1 H), 6.88 (s, 1
1
3
H), 1.35 (s, 9 H) ppm. C NMR (100 MHz, CDCl ): δ = 185.4, 164.6,
3
1
1
47.6, 147.0, 135.0, 132.5, 131.6, 129.9, 129.0, 121.3, 120.9, 112.8,
–
1
12.4, 34.8, 31.5 ppm. IR (KBr): ν = 1707, 1651 cm . HRMS (ESI):
˜
+
calcd. for C H O [M + H] 279.1385; found 279.1364.
19 20 2
[
7] a) D. V. Kadnikov, R. C. Larock, Org. Lett. 2000, 2, 3643–3646; b) D. V.
Kadnikov, R. C. Larock, J. Org. Chem. 2003, 68, 9423–9432.
Supporting Information (see footnote on the first page of this
1
13
[8] M. Catellani, G. P. Chiusoli, M. C. Fagnola, G. Solari, Tetrahedron Lett. 1994,
5, 5923–5926.
article): Copies of H and C NMR spectra of all new compounds.
3
[
9] a) J. Wu, Y. Liao, Z. Yang, J. Org. Chem. 2001, 66, 3642; b) Y. Luo, J. Wu,
Tetrahedron 2009, 65, 6810–6814.
Acknowledgments
[
10] a) W.-M. Dai, K. W. Lai, Tetrahedron Lett. 2002, 43, 9377–9380; b) T. Yao,
D. Yue, R. C. Larock, J. Org. Chem. 2005, 70, 9985–9989.
11] F. G. Bordwell, Acc. Chem. Res. 1988, 21, 456–463.
12] a) M. Yoshida, K. Saito, Y. Fujino, T. Doi, Chem. Commun. 2012, 48, 11796–
11798; b) D.-W. Chuang, M. Ei-Shazly, B. Balaji, Y.-M. Chung, F.-R. Chang,
Y.-C. Wu, Eur. J. Org. Chem. 2012, 4533–4540.
13] a) Y. Weng, Q. Chen, W. Su, J. Org. Chem. 2014, 79, 4218–4224; b) H.-M.
Sim, C.-Y. Lee, P. L. R. Ee, M.-L. Go, Eur. J. Pharm. Sci. 2008, 35, 293–306;
c) A. Pelter, R. S. Ward, H. G. Heller, J. Chem. Soc. Perkin Trans. 1 1979,
The authors thank the University Grants Commission (UGC),
New Delhi for a Junior Research Fellowship (JRF) to A. C., the
Science and Engineering Research Board (SERB), the Depart-
ment of Science and Technology (DST), New Delhi (grant num-
ber SR/S1/OC-61/2011) for a research grant to S. S., and the
Department of Chemistry, Indian Institute of Technology (IIT)
Madras for providing infrastructure.
[
[
[
3
28–329; d) C. Beney, A.-M. Mariotte, A. Boumendjel, Heterocycles 2001,
5
5, 967–972.
[
14] R. Irie, A. Tanoue, S. Urakawa, T. Imahori, K. Igawa, T. Matsumoto, K.
Keywords: Synthetic methods · Oxygen heterocycles ·
Carbonylation · Cross-coupling · Annulation · Palladium
Tomooka, S. Kikuta, T. Uchida, T. Katsuki, Chem. Lett. 2011, 40, 1343–
1
345.
15] a) J. J. Hirner, D. J. Faizi, S. A. Blum, J. Am. Chem. Soc. 2014, 136, 4740–
745; b) Y. Liu, S. Ma, Org. Lett. 2012, 14, 720–723.
[
[
4
16] T. Wang, Z.-Y. Li, A.-L. Xie, X.-J. Yao, X.-P. Cao, D. Cao, J. Org. Chem. 2011,
76, 3231–3238.
[
1] a) R. O'Kennedy, R. D. Thornes (Eds.), Coumarins: Biology, Applications and
Mode of Action, Wiley, New York, 1997; b) R. D. H. Murray, J. Mendez,
S. A. Brown, The Natural Coumarins: Occurrence, Chemistry and Biochemis-
try, Wiley, New York, 1982.
[17] a) S. Torii, H. Okumoto, L. H. Xu, M. Sadakane, M. V. Shostakovsky, A. B.
Ponomaryov, V. N. Alinin, Tetrahedron 1993, 49, 6773–6784; b) H. Miao,
Z. Yang, Org. Lett. 2000, 2, 1765; c) E. Awuah, A. Capretta, Org. Lett. 2009,
11, 3210–3213; d) Q. Yang, H. Alper, J. Org. Chem. 2010, 75, 948–950; e)
Y. Wang, J. Liu, C. Xia, Tetrahedron Lett. 2011, 52, 1587–1591; f) L. Xue, L.
Shi, Y. Han, C. Xia, H. V. Huynh, F. Li, Dalton Trans. 2011, 40, 7632–7638.
[
2] a) S. Penta (Ed.), Advances in Structure and Activity Relationship of Couma-
rin, Academic Press, New York, 2015; b) B. Naser-Hijazi, B. Stolze, K. S.
Zanker, Second Proceedings of the International Society of Coumarin Inves-
tigators, Springer, Berlin, 1994; c) H. Zhao, A. C. Donnelly, B. R. Kusuma,
G. E. L. Brandt, D. Brown, R. A. Rajewski, G. Vielhauer, J. Holzbeierlein,
M. S. Cohen, B. S. J. Blagg, J. Med. Chem. 2011, 54, 3839–3853; d) T.
Received: May 10, 2016
Published Online: ■
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Carbonylative Annulation
A. Chandrasekhar, V. Ramkumar,
S. Sankararaman* ........................... 1–10
Highly Selective and Modular Syn-
thesis of 3-Aryl-4-(arylethynyl)-2H-
chromen-2-ones from 2-Iodoaryl 2-
Arylacetates through a Carbonyl-
ative Sonogashira Coupling–Intra-
molecular Aldol Cascade Reaction
A modular approach for the synthesis method was used to prepare 24 differ-
of 3-aryl-4-(arylethynyl)-2H-chromen- ent 3,4-disubstitued 2H-chromen-2-
2
-ones from iodoaryl 2-arylacetates one derivatives in good to excellent
and arylacetylenes has been devel- yields.
oped. This highly selective general
DOI: 10.1002/ejoc.201600569
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