Rh(I)-catalyzed cross-coupling reactions of alkenyl tosylates with potassium aryltrifluoroborates

Article abstract of DOI:10.1016/j.tetlet.2006.07.085

RhCl(PPh₃)₃/DPPF was successfully employed as an efficient catalyst in the Suzuki-Miyaura cross-coupling reactions of potassium aryltrifluoroborates with alkenyl tosylates, affording the corresponding products in good to excellent yi

Full text of DOI:10.1016/j.tetlet.2006.07.085

Tetrahedron Letters 47 (2006) 6747–6750
Rh(I)-catalyzed cross-coupling reactions of alkenyl tosylates
with potassium aryltrifluoroborates
a
a
Jie Wu,a,b, Liang Zhang and Yong Luo
*
aDepartment of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry,
Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China
Received 6 June 2006; revised 18 July 2006; accepted 19 July 2006
Available online 7 August 2006
Abstract—RhCl(PPh3)3/DPPF was successfully employed as an efficient catalyst in the Suzuki–Miyaura cross-coupling reactions of
potassium aryltrifluoroborates with alkenyl tosylates, affording the corresponding products in good to excellent yields.
Ó 2006 Elsevier Ltd. All rights reserved.
Transition-metal catalyzed cross-coupling reactions,
extensively employed in a wide range of organic chemis-
try, are arguably one of the most powerful methods for
carbon–carbon bond formation.1 Recently, rhodium
catalyzed cross-coupling reaction captured much atten-
tion. Electron rich arylrhodium intermediate may
undergo an oxidative addition of electrophilic aromatic
substrate.2 The stoichiometric activation of aryl chlo-
rides on a phenylrhodium complex has been realized.3
Moreover, these rhodium catalysts have been employed
in the catalytic cross-coupling of arylboron reagents
with acid anhydrides,2 aryl bromides, and electron-defi-
cient aryl chlorides,4 as well as in the cross-coupling of
arylzinc reagents with aryl iodides.2 Not known is a sys-
tem capable of handling triflates and arenesulfonates.
Recently, arenesulfonates are emerging as important
alternatives to aryl/vinyl triflates and halides in transi-
tion metal-catalyzed cross-coupling reactions since they
are less expensive, more stable, and easier to handle than
the corresponding triflates.5,6 For example, remarkable
progress of using arenesulfonates as electrophiles for
Suzuki–Miyaura cross-coupling reactions have been
made even though arenesulfonates are relatively unreac-
tive compared to the corresponding halides and tri-
flates.5 This would be of great interest if rhodium
could be utilized as an efficient catalyst for coupling
reactions of arenesulfonates.
Among the cross-coupling reactions, Suzuki–Miyaura
reaction is of the greatest practical importance.7 A draw-
back associated with the use of boronic acids is the
structural ambiguity, namely, the formation of the tri-
meric anhydride (boroxine).8 An encouraging improve-
ment is the use of trifluoroborates, which have been
reported to couple with aryl halides or triflate catalyzed
by palladium or nickel.9 In view of arenesulfonates’ eas-
ier preparation, increased stability, and less expensive
relative to aryl triflates, as well as to broaden the appli-
cation of rhodium-catalyzed cross-coupling reactions, it
is of significant interest to develop general protocols to
employ arenesulfonates for rhodium-catalyzed cross-
coupling reactions of potassium trifluoroborates.
As part of our efforts to develop new approaches for the
synthesis of some natural product-like molecules with
biological activities,10 we became interested in some
privileged scaffolds, such as furan-2(5H)-one, coumarin,
pyrone, and quinolin-2(1H)-one derivatives due to their
extraordinary biological activities.10,11 The structural
similarity of 4-hydroxycoumarin with 4-hydroxy-
2(1H)-quinolone, 4-hydroxy-pyrones, and 4-hydroxy-
2(5H)-furanones led us to envisage that their 4-tosyloxy
species could be employed in cross-coupling reactions as
good substrates. Herein, we disclose our preliminary
results, which represent the first example of rhodium
catalyzed Suzuki–Miyaura couplings of alkenyl tosyl-
ates with potassium aryltrifluoroborates.
*
These tosylates were prepared simply from the
Corresponding author. Tel.: +86 2155664619; fax: +86
2165102412; e-mail: jie_wu@fudan.edu.cn
corresponding 4-hydroxy species with p-toluenesulfonyl
0040-4039/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2006.07.085

6748
J. Wu et al. / Tetrahedron Letters 47 (2006) 6747–6750
Table 1. Rh(I)-catalyzed coupling reaction of tosylate 1 with potas-
chloride in the presence of triethylamine (Fig. 1). Initial
studies were aimed to find optimal reaction conditions
for this coupling reaction. Our investigation commenced
with the reaction of 4-tosyloxycoumarin 1b and potas-
sium phenyltrifluoroborate (Scheme 1). Under the reac-
tion conditions shown in Scheme 1, the desired product
2c, was obtained in a promising yield (44%). Poor results
were observed when other phosphine-based ligands
(dppp, P(o-tolyl)3, P(Cy)3, 2-tBu2P biphenyl, 2-Cy2P
biphenyl) were employed. Without the addition of any
ligands, only trace amount of product was detected. Tol-
uene was proved to be the best choice after solvent
screening (benzene, THF, EtOH, and H2O, DMSO,
dioxane). Among the bases investigated (KF, K2CO3,
K3PO4, Cs2CO3, CsF, K2HPO4, Na2CO3, LiOH,
NaOH, KOH), K2HPO4 was the most efficient (61%
yield). The reaction was retarded when the temperature
was decreased.
sium aryltrifluoroboratesa,12
OTs
Ar
RhCl(PPh3)3 (2 mol %)
dppf (2 mol %)
+
ArBF3K
K2HPO4 (1.0 M in H2O)
toluene, 80 C, 12 h
X
1
O
X
2
O
°
Entry
Tosylate
ArBF3K
Product
Yieldb (%)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
1a
1a
1b
1b
1b
1c
1c
1d
1d
1e
1e
1f
4-MeC6H4BF3K
4-FC6H4BF3K
PhBF3K
2a
2b
2c
2d
2e
2f
66
64
61
75
71
67
75
54
63
69
84
62
92
94
89
99
89
42
46
4-MeC6H4BF3K
4-FC6H4BF3K
4-MeC6H4BF3K
4-FC6H4BF3K
4-MeC6H4BF3K
4-FC6H4BF3K
4-MeC6H4BF3K
4-FC6H4BF3K
PhBF3K
4-MeC6H4BF3K
4-FC6H4BF3K
PhBF3K
4-MeC6H4BF3K
4-FC6H4BF3K
4-MeC6H4BF3K
4-FC6H4BF3K
2g
2h
2i
2j
2k
2l
A variety of arenesulfonates and trifluoroborates have
thus been examined for the Rh(I)-catalyzed cross-cou-
pling reactions using the optimized catalyst system,
and the results are summarized in Table 1. As shown
in Table 1, substituted 4-tosyloxycouamrins 1b–f
showed broad generality when coupled with various
potassium aryltrifluoroborates, and substrates with
electron-withdrawing groups gave better results.
4-Tosyloxypyrone 1g was also a good partner in this
coupling reaction and excellent yields were obtained
with various potassium aryl trifluoroborates, while reac-
tions of 4-hydroxy-2(5H)-furanone 1a and 4-tosyloxy-
quinolin-2(1H)-one 1h afforded moderate yields
(entries 1 and 2, 18 and 19).
1f
2m
2n
2o
2p
2q
2r
2s
1f
1g
1g
1g
1h
1h
a Reaction conditions: substrate (0.25 mmol), RhCl(PPh3)3 (2 mol %),
dppf (2 mol %), K2HPO4 (1 mL, 1 M in water), toluene (2 mL),
80 °C, 12 h.
b Isolated yield.
could be directly used for biological assays. This proto-
col not only represents the first example of rhodium-cat-
alyzed Suzuki–Miyaura couplings of alkenyl tosylates
with potassium aryl trifluoroborates, but also demon-
strates the versatility of rhodium catalysts and broadens
the prospect of their applications in organic synthesis.
In summary, we have described an effective rhodium cat-
alyst system for the Suzuki–Miyaura cross-coupling of
alkenyl tosylates with potassium aryltrifluoroborates.
Some natural product-like compounds, such as 4-substi-
tuted furan-2(5H)-ones, coumarins, pyrones, and quino-
lin-2(1H)-ones, have been synthesized efficiently and
Acknowledgements
OTs
O
OTs
O
OTs
O
OTs
We thank Professor Pengyuan Yang for his invaluable
advice during the course of this research. Financial
support from National Natural Science Foundation of
China (20502004), Ministry of Education of China, the
Science and Technology Commission of Shanghai
Municipality (05ZR14013), and Fudan University is
gratefully acknowledged.
O
O
O
O
O
O
1c
1d
1a
1b
OTs
OTs
O
OTs
OTs
O
Cl
F
N
O
O
O
O
CH3
1f
1g
1e
1h
References and notes
Figure 1.
1. (a) Tsuji, J. Palladium Reagents and Catalysts, 2nd ed.;
John Wiley and Sons: Chichester, UK, 2004; (b) de
Meijere, A.; Diederich, F. Metal-Catalyzed Cross-Cou-
pling Reactions, 2nd ed.; John Wiley and Sons: Weinheim,
Germany, 2004.
2. (a) Oguma, K.; Miura, M.; Nomura, M. J. Organomet.
Chem. 2002, 648, 297; (b) Sugihara, T.; Satoh, T.; Miura,
M.; Nomura, M. Angew. Chem., Int. Ed. 2003, 42, 4672;
(c) Sugihara, T.; Satoh, T.; Miura, M.; Nomura, M. Adv.
Synth. Catal. 2004, 346, 1765; (d) Frost, C. G.; Wads-
Ph
OTs
RhCl(PPh3)3 (2 mol %)
dppf (2 mol %)
+
PhBF3K
°
Toluene, 80 C
O
O
O
O
CsF(1.0 M in H2O)
44%
2c
1b
Scheme 1.

J. Wu et al. / Tetrahedron Letters 47 (2006) 6747–6750
6749
worth, K. J. Chem. Commun. 2001, 2316; (e) Gooben, L.
J.; Paetzold, J. Adv. Synth. Catal. 2004, 346, 1665; (f)
Yamane, M.; Uera, K.; Narasaka, K. Chem. Lett. 2004,
424; (g) Hossain, K. M.; Takagi, K. Chem. Lett. 1999,
1241.
10. (a) Wu, J.; Zhang, L.; Sun, X. Chem. Lett. 2005, 34, 550;
(b) Wu, J.; Sun, X.; Zhang, L. Chem. Lett. 2005, 34, 796;
(c) Wu, J.; Zhang, L.; Diao, T.-N. Synlett 2005, 2653; (d)
Wu, J.; Zhang, L.; Xia, H.-G. Tetrahedron Lett. 2006, 47,
1525; (e) Wu, J.; Xia, H.-G.; Gao, K. Org. Biomol. Chem.
2006, 4, 126; (f) Wu, J.; Wang, X. Org. Biomol. Chem.
2006, 4, 1348.
3. Grushin, V. V.; Marshall, W. J. J. Am. Chem. Soc. 2004,
126, 3068.
4. Ueura, K.; Satoh, T.; Miura, M. Org. Lett. 2005, 7, 2229.
5. For Suzuki–Miyaura reaction, see: (a) Tang, Z.-Y.; Hu,
Q.-S. J. Am. Chem. Soc. 2004, 126, 3058; (b) Nguyen, H.
N.; Huang, X.; Buchwald, S. L. J. Am. Chem. Soc. 2003,
125, 11818; (c) Percec, V.; Bae, J.-Y.; Hill, D. H. J. Org.
Chem. 1995, 60, 1060; (d) Kobayashi, Y.; Mizojiri, R.
Tetrahedron Lett. 1996, 37, 8531; (e) Zim, D.; Lando, V.
R.; Dupont, J.; Monteiro, A. L. Org. Lett. 2001, 3, 3049;
(f) Lakshman, M. K.; Thomson, P. F.; Nuqui, M. A.;
Hilmer, J. H.; Sevova, N.; Boggess, B. Org. Lett. 2002, 4,
1479; (g) Huffman, M. A.; Yasuda, N. Synlett 1999, 471;
(h) Wu, J.; Wang, L.; Fathi, R.; Yang, Z. Tetrahedron
Lett. 2002, 43, 4395; (i) Wu, J.; Zhu, Q.; Wang, L.; Fathi,
R.; Yang, Z. J. Org. Chem. 2003, 68, 670; (j) Percec, V.;
Golding, G. M.; Smidrkal, J.; Weichold, O. J. Org. Chem.
2004, 69, 3447; (k) Baxter, J. M.; Steinhuebel, D.; Palucki,
M.; Davies, I. W. Org. Lett. 2005, 7, 215; (l) Tang, Z. Y.;
Hu, Q.-S. Adv. Synth. Catal. 2004, 346, 1635; (m)
Steinhuebel, D.; Baxter, J. M.; Palucki, M.; Davies, I.
W. J. Org. Chem. 2005, 70, 10124; (n) Netherton, M. R.;
Fu, G. C. Angew. Chem., Int. Ed. 2002, 41, 3910.
11. Selected examples: (a) Xia, Y.; Yang, Z.-Y.; Xia, P.;
Hackl, T.; Hamel, E.; Mauger, A.; Wu, J.-H.; Lee, K.-H.
J. Med. Chem. 2001, 44, 3932; (b) Chen, Y.-L.; Fang,
K.-C.; Sheu, J.-Y.; Hsu, S.-L.; Tzeng, C.-C. J. Med. Chem.
2001, 44, 2374; (c) Renau, T. E.; Sanchez, J. P.; Gage, J.
W.; Dever, J. A.; Shapiro, M. A.; Gracheck, S. J.;
Domagala, J. M. J. Med. Chem. 1996, 39, 729; (d) Yang,
S. S.; Cragg, G. M.; Newman, D. J.; Bader, J. P. J. Nat.
´
Prod. 2001, 64, 265; (e) Murray, R. D. H.; Mendez, J.;
Brown, S. A. The Natural Coumarins: Occurrence, Chem-
istry, and Biochemistry; Wiley: New York, 1982.
12. General procedure for Suzuki–Miyaura coupling of alkenyl
tosylates with potassium aryl trifuoroborates: A mixture of
alkenyl tosylate 1 (0.25 mmol), potassium aryltrifluoro-
borate (1.5 equiv), RhCl(PPh3)3 (2 mol %), and DPPF
(2 mol %) was added into a reaction tube under nitrogen
atmosphere. Then toluene (2.0 mL) and aqueous K2HPO4
(1.0 mL, 1.0 M solution) were added subsequently. The
reaction mixture was stirred for 12 h at 80 °C. After the
reaction was completed and monitored by TLC, the
organic phase was separated and purified directly by flash
chromatography column (silica gel) to afford the corre-
sponding product 2. (All products are known compounds.
The data of products were identical with the literature
reports.) 4-p-Tolylfuran-2(5H)-one 2a:5l 66% yield, 1H
NMR (400 MHz, CDCl3): d (ppm) 2.42 (s, 3H), 5.21 (s,
2H), 6.33 (s, 1H), 7.27 (d, J = 8.24 Hz, 2H), 7.40 (d,
J = 7.80 Hz, 2H). 4-(4-Fluorophenyl)furan-2(5H)-one
2b:5i 64% yield, 1H NMR (400 MHz, CDCl3): d (ppm)
5.21 (s, 2H), 6.34 (s, 1H), 7.18–7.20 (m, 2H), 7.51–7.53 (m,
2H). 4-Phenyl-2H-chromen-2-one 2c:13 61% yield, 1H
NMR (400 MHz, CDCl3): d (ppm) 6.39 (s, 1H), 7.25–
7.54 (m, 9H). 13C NMR (125.7 MHz): d (ppm) 161.0,
155.9, 154.5, 135.5, 132.2, 129.9, 129.1, 128.7, 127.3, 124.4,
119.3, 117.6, 115.5. MS [C15H10O2], m/z (M++1): calcd
223, found 223. 4-p-Tolyl-2H-chromen-2-one 2d:13 75%
6. (a) Lei, J.-G.; Xu, M.-H.; Lin, G.-Q. Synlett 2004, 2364;
(b) Fu, X.; Zhang, S.; Yin, J.; Schumacher, D. P.
Tetrahedron Lett. 2002, 43, 6673; (c) Wu, J.; Liao, Y.;
Yang, Z. J. Org. Chem. 2001, 66, 3642; (d) Fu, X.; Zhang,
S.; Yin, J.; McAllister, T. L.; Jiang, S. A.; Tann, C.-H.;
Thiruvengadam, T. K.; Zhang, F. Tetrahedron Lett. 2002,
43, 573; (e) Roy, A. H.; Hartwig, J. F. J. Am. Chem. Soc.
´
2003, 125, 8704; (f) Furstner, A.; Leitner, A.; Mendez, M.;
¨
Krause, H. J. Am. Chem. Soc. 2002, 124, 13856; (g)
Badone, D.; Cecchi, R.; Guzzi, U. J. Org. Chem. 1992, 57,
6321; (h) Nagatsugi, F.; Uemura, K.; Nakashima, S.;
Minoru, M.; Sasaki, S. Tetrahedron Lett. 1995, 36, 421; (i)
Schio, L.; Chatreaux, F.; Klich, M. Tetrahedron Lett.
2000, 41, 1543.
7. For recent reviews: (a) Miyaura, N. Top. Curr. Chem.
2002, 219, 11; (b) Suzuki, A. J. Organomet. Chem. 1999,
576, 147; (c) Culkin, D. A.; Hartwig, J. F. Acc. Chem. Res.
2003, 36, 234; (d) Hassan, J.; Sevigon, M.; Gozzi, C.;
Schulz, E.; Lemaire, M. Chem. Rev. 2002, 102, 1359; (e)
Kotha, S.; Lahiri, K.; Kashinath, D. Tetrahedron 2002,
9633.
1
yield, H NMR (500 MHz, CDCl3): d (ppm) 2.46 (s, 3H),
6.36 (s, 1H), 7.24 (t, J = 7.5 Hz, 1H), 7.32–7.37 (m, 4H),
7.41 (d, J = 8.0 Hz, 1H), 7.53–7.53 (m, 2H). 13C NMR
(125.7 MHz): d (ppm) 161.1, 156.0, 154.5, 140.2, 132.6,
132.1, 129.8, 128.7, 127.3, 124.3, 119.4, 117.6, 115.2, 21.6.
MS [C16H12O2], m/z (M++1): calcd 237, found 237. 4-(4-
Fluorophenyl)-2H-chromen-2-one 2e:13 71% yield, 1H
NMR (400 MHz, CDCl3): d (ppm) 6.36 (s, 1H), 7.23–
7.59 (m, 8H). 13C NMR (125.7 MHz): d (ppm) 160.8,
154.8, 154.4, 146.7, 132.3, 130.7, 130.6, 127.0, 124.5, 119.1,
117.7, 116.4, 116.3, 115.6. MS [C15H9FO2], m/z (M++1):
calcd 241, found 241.6-Methyl-4-p-tolyl-2H-chromen-2-
one 2f:14 67% yield, 1H NMR (400 MHz, CDCl3): d (ppm)
2.34 (s, 3H), 2.47 (s, 3H), 6.34 (s, 1H), 7.30 (d, J = 8 Hz,
2H), 7.35 (m, 5H). 4-(4-Fluorophenyl)-6-methyl-2H-chro-
men-2-one 2g:10d 75% yield, 1H NMR (400 MHz, CDCl3):
d (ppm) 2.35 (s, 3H), 6.33 (s, 1H), 7.21–7.44 (m, 7H). IR
(KBr, cmÀ1): 3047, 2921, 1742, 1720, 1566, 1225, 839. MS
[C16H11FO2], m/z (M+): calcd 254, found 254. HRMS:
Anal. Calcd for C16H11FO2, 254.07431. Found 254.07436.
6,7-Dimethyl-4-p-tolyl-2H-chromen-2-one 2h:10d 54%
yield, 1H NMR (500 MHz, CDCl3): d (ppm) 2.23 (s,
3H), 2.35 (s, 3H), 2.46 (s, 3H), 6.27 (s, 1H), 7.17 (s, 1H),
7.23 (s, 1H), 7.34 (t, J = 9 Hz, 4H). 13C NMR
(125.7 MHz): d (ppm) 161.4, 155.7, 152.7, 141.9, 139.7,
132.9, 132.8, 129.5, 128.4, 127.0, 117.9, 116.8, 113.9, 21.4,
8. Onak, T. Organoborane Chemistry; Academic Press: New
York, 1975.
9. (a) Arvela, R. K.; Leadbeater, N. E.; Mack, T. L.;
Kormos, C. M. Tetrahedron Lett. 2006, 47, 217; (b)
Molander, G. A.; Felix, L. A. J. Org. Chem. 2005, 70,
3950; (c) Batey, R. A.; Quach, T. D. Tetrahedron Lett.
2001, 42, 9099; (d) Molander, G. A.; Biolatto, B. Org.
Lett. 2002, 4, 1867; (e) Molander, G. A.; Biolatto, B. . J.
Org. Chem. 2003, 68, 4302; (f) Barder, T. E.; Buchwald, S.
L. Org. Lett. 2004, 6, 2649, and references cited therein; (g)
Darses, S.; Genet, J.-P. Eur. J. Org. Chem. 2003, 4313; (h)
Molander, G. A.; Figuroa, R. Aldrichim. Acta 2005,
38, 49; (i) Darses, S.; Brayer, J.-L.; Demoute, J.-P.; Genet,
J.-P. Tetrahedron Lett. 1997, 38, 4393; (j) Darses, S.;
Michaud, G.; Genet, J.-P. Eur. J. Org. Chem. 1999, 1875;
(k) Xia, M.; Chen, Z.-C. J. Chem. Res. (S) 1999, 400; (l)
Kabalka, G. W.; Al-Masum, M. Tetrahedron Lett. 2005,
46, 6329; (m) Molander, G. A.; Katona, B. W.;
Machrouhi, F. J. Org. Chem. 2002, 67, 8416; (n) Fang,
G.-H.; Yan, Z.-J.; Deng, M.-Z. Org. Lett. 2004, 6, 357.

6750
J. Wu et al. / Tetrahedron Letters 47 (2006) 6747–6750
20.2, 19.3. MS [C18H16O2], m/z (M+): calcd 264, found
2H-pyran-2-one 2p:17 99% yield, 1H NMR (400 MHz,
CDCl3): d (ppm) 2.31 (s, 3H), 2.41 (s, 3H), 6.30 (s, 1H),
6.34 (s, 1H), 7.27 (d, J = 7.80 Hz, 2H), 7.46 (d,
264. HRMS: Anal. Calcd for C18H16O2, 264.11503. Found
264.11556. 4-(4-Fluorophenyl)-6,7-dimethyl-2H-chromen-
2-one 2i:10d 63% yield, 1H NMR (400 MHz, CDCl3): d
(ppm) 2.24 (s, 3H), 2.36 (s, 3H), 6.27 (s, 1H), 7.16–7.44 (m,
6H). 4-(4-Fluorophenyl)-6,7-dimethyl-2H-chromen-2-one
2i:10d 63% yield, 1H NMR (400 MHz, CDCl3): d (ppm)
2.24 (s, 3H), 2.36 (s, 3H), 6.27 (s, 1H), 7.16–7.44 (m, 6H).
6-Chloro-4-p-tolyl-2H-chromen-2-one 2j:10d 69% yield, 1H
NMR (500 MHz, CDCl3): d (ppm) 2.47 (s, 3H), 6.39 (s,
1H), 7.33–7.37 (m, 5H), 7.49–7.50 (m, 2H). IR (KBr,
cmÀ1): 3063, 2914, 1735, 1122, 819. MS [C16H11ClO2], m/z
(M+): calcd 270, found 270. HRMS: Anal. Calcd for
C16H11ClO2, 270.04476. Found 270.04385. 6-Chloro-4-(4-
fluorophenyl)-2H-chromen-2-one 2k:10d 84% yield, 1H
NMR (400 MHz, CDCl3): d (ppm) 6.38 (s, 1H), 7.24–
7.42 (m, 7H). IR (KBr, cmÀ1): 2920, 2850, 1740, 1721,
1232, 936, 886, 823. MS [C15H8ClFO2], m/z (M+): calcd
274, found 274. HRMS: Anal. Calcd for C15H8ClFO2,
274.01969. Found 274.01942. 6-Fluoro-4-phenyl-2H-chro-
men-2-one 2l:15 62% yield, 1H NMR (400 MHz, CDCl3): d
(ppm) 6.43 (s, 1H), 7.18–7.46 (m, 4H), 7.54–7.56 (m, 4H).
6-Fluoro-4-p-tolyl-2H-chromen-2-one 2m:10d 92% yield,
1H NMR (400 MHz, CDCl3): d (ppm) 2.46 (s, 3H), 6.41 (s,
1H), 7.20–7.40 (m, 7H). IR (KBr, cmÀ1): 3075, 2925, 1717,
1433, 1251, 816. MS [C16H11FO2], m/z (M+): calcd 254,
found 254. HRMS: Anal. Calcd for C16H11FO2,
254.07431. Found 254.07370. 6-Fluoro-4-(4-fluorophen-
yl)-2H-chromen-2-one 2n:10d 94% yield, 1H NMR
(400 MHz, CDCl3): d (ppm) 6.41 (s, 1H), 7.12–7.16 (m,
1H), 7.23–7.28 (m, 3H), 7.38–7.46 (m, 3H). IR (KBr,
cmÀ1): 2923, 2850, 1745, 1221, 943, 840, 825. MS
[C15H8F2O2], m/z (M+): calcd 258, found 258. HRMS:
Anal. Calcd for C15H8F2O2, 258.04924. Found 258.04895.
6-Methyl-4-phenyl-2H-pyran-2-one 2o:16 89% yield, 1H
NMR (400 MHz, CDCl3): d (ppm) 2.33 (s, 3H), 6.31 (s,
1H), 6.36 (s, 1H), 7.47–7.57 (m, 5H). 6-Methyl-4-p-tolyl-
J = 7.76 Hz,
2H).
4-(4-Fluorophenyl)-6-methyl-2H-
pyran-2-one 2q:10b 89% yield, 1H NMR (400 MHz,
CDCl3): d (ppm) 2.33 (s, 3H), 6.27 (s, 1H), 6.31 (s, 1H),
7.15–7.19 (m, 2H), 7.55–7.59 (m, 2H). 13C NMR
(125.7 MHz): d (ppm) 165.4, 163.4, 163.1, 163.0, 154.1,
132.0, 130.2, 130.1, 116.9, 116.7, 107.5, 103.4, 20.3. MS
[C12H9FO2], m/z (M++Na): calcd 227, found 227. 1-
Methyl-4-p-tolylquinolin-2(1H)-one 2r:10d 42% yield, 1H
NMR (500 MHz, CDCl3): d (ppm) 2.45 (s, 3H), 3.78 (s,
3H), 6.69 (s, 1H), 7.18 (t, J = 7 Hz, 1H), 7.29–7.33 (m,
4H), 7.44 (d, J = 8.5 Hz, 1H), 7.58–7.60 (m, 2H). 13C
NMR (125.7 MHz): d (ppm) 162.1, 151.0, 140.4, 138.7,
134.2, 130.6, 129.3, 128.9, 127.8, 122.6, 121.9, 120.7, 114.5,
29.5, 21.3. MS [C17H15NO], m/z (M+): calcd 249, found
249. HRMS: Anal. Calcd for C17H15NO, 249.11536.
Found 249.11678. 4-(4-Fluorophenyl)-1-methylquinolin-
1
2(1H)-one 2s:10b 50% yield, H NMR (400 MHz, CDCl3):
d (ppm) 3.79 (s, 3H), 6.67 (s, 1H), 7.17–7.22 (m, 3H), 7.39–
7.46 (m, 3H), 7.51 (d, J = 8.28 Hz, 1H), 7.58 (d,
J = 7.8 Hz, 1H). 13C NMR (125.7 MHz): d (ppm) 164.0,
162.1, 161.1, 149.9, 140.7, 133.6, 131.8, 131.7, 127.5, 122.8,
121.5, 120.1, 116.4, 116.3, 116.0, 29.8. MS [C16H12FNO],
m/z (M+): calcd 253, found 253. HRMS: Anal. Calcd for
C16H12FNO, 253.09029. Found 253.09034.
13. Wu, J.; Yang, Z. J. Org. Chem. 2001, 66, 7875.
14. Natarajan, M.; Manimaran, T.; Ramakrishnan, V. T.
Indian J. Chem., Sect. B: Org. Chem. Inclu. Med. Chem.
1984, 23B, 529.
15. Gandolfi, C. A.; Tofanetti, O.; Spinelli, S.; Cipolla, P.;
Tognella, S. Eur. Pat. Appl. 1986, 34.
16. Cherry, K.; Parrain, J.-L.; Thibonnet, J.; Duchene, A.;
Abarbri, M. J. Org. Chem. 2005, 70, 6669.
17. Fairlamb, I. J. S.; Marrison, L. R.; Dickinson, J. M.; Lu,
F.-J.; Schmidt, J. P. Bioorg. Med. Chem. 2004, 12, 4285.