3162
S. Kim et al.
LETTER
(6) (a) Kim, S.; Lim, C. J. Angew. Chem. Int. Ed. 2002, 41,
E
E
E
E
E
E
E
E
3265. (b) Kim, S.; Song, H.-J. Synlett 2002, 2110. (c) Kim,
S.; Lim, C. J. Bull. Korean Chem. Soc. 2003, 24, 1219.
(d) Lee, S.; Lim, C. J.; Kim, S. Bull. Korean Chem. Soc.
2004, 25, 1611.
2, CO
V-40
X
O
10
E = CO2Et
X = SO2CH2CH=CH2
12
11
(7) Kim, S.; Kim, S.; Otsuka, N.; Ryu, I. Angew. Chem. Int. Ed.
2005, 44, 6183.
E
E
O
O
(8) For examples of radical reactions involving two radical C1
synthons, see: (a) Ryu, I.; Kuriyama, H.; Minakata, S.;
Komatsu, M.; Yoon, J.-Y.; Kim, S. J. Am. Chem. Soc. 1999,
121, 12190. (b) Ryu, I.; Kuriyama, H.; Miyazato, H.;
Minakata, S.; Komatsu, M.; Yoon, J.-Y.; Kim, S. Bull.
Chem. Soc. Jpn. 2004, 77, 1407.
(9) For reviews on acyl radicals and radical carbonylations, see:
(a) Chatgilialogu, C.; Crich, D.; Komatsu, M.; Ryu, I. Chem.
Rev. 1999, 99, 1991. (b) Ryu, I.; Sonoda, N. Angew. Chem.
Int. Ed. 1996, 35, 1050. (c) Ryu, I.; Sonoda, N.; Curran, D.
P. Chem. Rev. 1996, 96, 177.
O
Y
O
13a:
Y = CN
13b: Y = OMe (59%)
O
NC
O
O
Y
H
H
H
H
1) 2, 130 atm CO, V-40
+
2) MeOH
X
16 (43%)
15a: Y = CN
15b: Y = OMe (45%)
(10) After removal of heptane from the reaction mixture, IR and
13C NMR were taken. IR (polymer): 1711 (C=O), 2343,
2361 (CN) cm–1. 13C NMR (100 MHz, CDCl3): d = 114.5
(CN), 178.8 (C=O) cm–1.
14
Scheme 4
(11) (a) Corey, E. J.; Schmidt, G. Tetrahedron Lett. 1980, 21,
731. (b) Bal, B. S.; Childers, W. E. Jr.; Pinnick, H. W.
Tetrahedron 1981, 37, 2091.
(12) Similarly, quenching with aniline afforded the
corresponding amide in 78% yield.
In summary, we have achieved the first free radical cyano-
carbonylation, which is based on the use of double radical
C1 synthons, carbon monoxide and p-tolylsulfonyl
cyanide. It should be also noted that the reaction can be
carried out successfully under tin-free radical conditions.
(13) Smith, T. A. K.; Whitham, G. H. J. Chem. Soc., Chem.
Commun. 1985, 897.
(14) For a primary acyl radical, see: (a) Nagahara, K.; Ryu, I.;
Kambe, N.; Komatsu, M.; Sonoda, N. J. Org. Chem. 1995,
60, 7384. (b) For a secondary acyl radical, see: Boese, W. T.;
Goldman, A. S. Tetrahedron Lett. 1992, 33, 2119. (c) For
decarbonylation rates of acyl radicals, see: Chatgilialoglu,
C.; Ferreri, C.; Lucarini, M.; Pedrielli, P. Organometallics
1995, 14, 2672.
Acknowledgment
SK is grateful to the CMDS and the KEPOC for financial support.
IR would like to thank Grant-in Aid for Scientific Research on Prio-
rity Areas (A) (444) from the MEXT, Japan.
(15) (a) Tsunoi, S.; Ryu, I.; Yamasaki, S.; Fukushima, H.;
Tanaka, M.; Komatsu, M.; Sonoda, N. J. Am. Chem. Soc.
1996, 118, 10670. (b) Ryu, I.; Kreimerman, S.; Araki, F.;
Nishitani, S.; Oderaotoshi, Y.; Minakata, S.; Komatsu, M. J.
Am. Chem. Soc. 2002, 124, 3812.
References
(1) For a review on acyl cyanides, see: (a) Thesing, J.; Witzel,
D.; Brehm, A. Angew. Chem. 1956, 68, 425. (b) Hünig, S.;
Schaller, R. Angew. Chem., Int. Ed. Engl. 1982, 21, 36.
(2) For recent reports on acyl cyanides see: (a) Yamamoto, Y.;
Kinpara, K.; Saigoku, T.; Takagishi, H.; Okuda, S.;
Nishiyama, H.; Itoh, K. J. Am. Chem. Soc. 2005, 127, 605.
(b) Duplais, C.; Bures, F.; Sapountzis, I.; Tobias, T. J.;
Cahiez, G.; Knochel, P. Angew. Chem. Int. Ed. 2004, 43,
2968. (c) Watahiki, T.; Ohba, S.; Oriyama, T. Org. Lett.
2003, 5, 2679. (d) Yoo, B. W.; Kim, D. Y.; Choi, J. W.;
Hwang, S. K.; Choi, K. I.; Kim, J. H. Bull. Korean Chem.
Soc. 2003, 24, 263. (e) Saikia, P.; Laskar, D. D.; Prajapati,
D.; Sandhu, J. S. Tetrahedron Lett. 2002, 43, 7525. (f)Yoo,
B. W.; Hwang, S. K.; Kim, D. Y.; Choi, J. W.; Ko, J. J.;
Choi, K. I.; Kim, J. H. Tetrahedron Lett. 2002, 43, 4813.
(3) (a) Cao, Y.-Q.; Du, Y.-F.; Chen, B.-H.; Li, J.-T. Synth.
Commun. 2004, 34, 2951. (b) Olah, G. A.; Arvanaghi, M.;
Prakash, G. K. S. Synthesis 1983, 636. (c) Ando, T.;
Kawate, T.; Tamawaki, J.; Hanafusa, T. Synthesis 1983, 637.
(4) Tanaka, M. Bull. Chem. Soc. Jpn. 1981, 54, 637.
(5) (a) Quiclet-Sire, B.; Zard, S. Z. J. Am. Chem. Soc. 1996, 118,
1209. (b) Guyader, F. L.; Quiclet-Sire, B.; Seguin, S.; Zard,
S. Z. J. Am. Chem. Soc. 1997, 119, 7410. (c) Xiang, J.;
Jiang, W.; Gong, J.; Fuchs, P. L. J. Am. Chem. Soc. 1997,
119, 4123. (d) Quiclet-Sire, B.; Seguin, S.; Zard, S. Z.
Angew. Chem. Int. Ed. 1998, 37, 2864. (e) Bertrand, F.;
Quiclet-Sire, B.; Seguin, S.; Zard, S. Z. Angew. Chem. Int.
Ed. 1999, 38, 1943.
(16) Typical Procedure:
Heptane (20 mL), 4-phenoxylbutyl allyl sulfone (51 mg, 0.2
mmol), p-tolylsulfonyl cyanide (57 mg, 0.3 mmol), and V-
40 (10 mg, 0.04 mmol) were placed in a 50 mL stainless steel
autoclave. The autoclave was sealed, purged three times
with 10 atm of CO, pressurized with 95 atm of CO, and then
heated at 100 °C with stirring for 12 h. After excess CO was
discharged at r.t., the reaction mixture was poured into a 100
mL round-bottom flask, quenched with excess MeOH at r.t.
for 4 h with stirring. After the solvent and MeOH were
removed under reduced pressure, the residue was purified by
a silica gel column chromatography using EtOAc and n-
hexane (1:20) as eluent to give 5-phenoxypentanoic acid
methyl ester (33 mg, 80%) and 5-phenoxypentanenitrile (2
mg, 6%). Caution! All operations should be done carefully
inside a fume hood.
5-Phenoxypentanoic Acid Methyl Ester (6).
1H NMR (400 MHz, CDCl3): d = 1.79–1.83 (m, 4 H), 2.37–
2.40 (m, 2 H), 3.66 (s, 3 H), 3.94–3.97 (m, 2 H), 6.86–6.93
(m, 3 H), 7.26–7.28 (m, 2 H). 13C NMR (100 MHz, CDCl3):
d = 21.7, 28.7, 33.7, 51.5, 67.2, 114.6, 120.6, 129.4, 158.9,
173.9. IR (polymer): 693, 756, 1171, 1247, 1498, 1601,
1738, 2951 cm–1. HRMS: m/z calcd for C12H16O3 [M+] =
208.1099; found: 208.1096.
Synlett 2005, No. 20, 3160–3162 © Thieme Stuttgart · New York