C. J. Lim, Bull. Korean Chem. Soc., 2003, 24, 1219; (c) S. Kim and
C. J. Lim, Angew. Chem., Int. Ed., 2002, 41, 3265; (d) S. Kim, C. J. Lim,
C. Song and W.-J. Chung, J. Am. Chem. Soc., 2002, 124, 14306; (e)
S. Kim, C. J. Lim, S.-E. Song and H.-Y. Kang, Chem. Commun., 2001,
1410.
4 (a) B. M. Trost, Science, 1991, 254, 1471; (b) R. A. Sheldon, Chem. Ind.
(London), 1992, 23, 903; (c) P. A. Wender, S. T. Handy and
D. L. Wright, Chem. Ind. (London), 1997, 19, 765.
5 For reviews of radical carbonylation, see: (a) I. Ryu, Chem. Soc. Rev.,
2001, 30, 16; (b) C. Chatgilialogu, D. Crich, M. Komatsu and I. Ryu,
Chem. Rev., 1999, 99, 1991; (c) I. Ryu and N. Sonoda, Angew. Chem.,
Int. Ed. Engl., 1996, 35, 1050; (d) I. Ryu, N. Sonoda and D. P. Curran,
Chem. Rev., 1996, 96, 177.
6 (a) C. Chatgilialoglu, in The Chemistry of Sulfones and Sulfoxides, ed.
S. Patai, Z. Rappoport and C. J. M. Stirling, Wiley, Chichester, 1988,
pp. 1089–1113; (b) C. Chatgilialoglu, L. Lunazzi and K. U. Ingold,
J. Org. Chem., 1983, 48, 3588; (c) R. S. Givens, B. Hrinczenko,
J. H.-S. Liu, B. Matuszewski and J. Tholen-Collison, J. Am. Chem. Soc.,
1984, 106, 1779.
The present approach could be further applied to the direct
conversion of alkylsulfonyl oxime ether 15 into the acylated oxime
ether 16 (eqn (7)),16 which is very useful for the preparation of
vicinal tricarbonyl compounds.17 The reaction could be success-
fully carried out at pressurized CO (50 atm) at 120 uC for 18 h
without the formation of 17 for primary alkylsulfonyl oxime
ethers. When the reaction was carried out with secondary
alkylsulfonyl oxime ether 15d under the same condition, 16d was
obtained in 71% yield along with some starting material 15d (21%).
Under 95 atm of CO, 15d was completely consumed to give 16d in
92% yield.
7 (a) B. Quiclet-Sire and S. Z. Zard, J. Am. Chem. Soc., 1996, 118, 1209;
(b) F. L. Guyader, B. Quiclet-Sire, S. Seguin and S. Z. Zard, J. Am.
Chem. Soc., 1997, 119, 7410; (c) B. Quiclet-Sire, S. Seguin and S. Z. Zard,
Angew. Chem., Int. Ed., 1998, 37, 2864; (d) F. Bertrand, B. Quiclet-Sire
and S. Z. Zard, Angew. Chem., Int. Ed., 1999, 38, 1943; (e) C. Ollivier
and P. Renaud, J. Am. Chem. Soc., 2001, 123, 4717.
ð7Þ
8 (a) S. Kim, S. Kim, N. Otsuka and I. Ryu, Angew. Chem., Int. Ed.,
2005, 44, 6183; (b) S. Kim, C. H. Cho, S. Kim, Y. Uenoyama and
I. Ryu, Synlett, 2005, 20, 3160; (c) S. Kim, K.-C. Lim, S. Kim and
I. Ryu, Adv. Synth. Catal., 2007, 349, 527.
9 For an account of alkyl allyl sulfone radical precursors, see: S. Kim and
S. Kim, Bull. Chem. Soc. Jpn., 2007, 80, 809.
10 (a) J.-M. Fang and M.-Y. Chen, Tetrahedron Lett., 1987, 28, 2853; (b)
D. H. R. Barton, J. Cs. Jaszberenyi and E. A. Theodorakis, Tetrahedron
Lett., 1991, 32, 3321; (c) D. H. R. Barton, J. Cs. Jaszberenyi and
E. A. Theodorakis, Tetrahedron, 1992, 48, 2613; (d) S. Kim and
H.-J. Song, Synlett, 2002, 12, 2110.
In conclusion, we have discovered the first simple and highly
efficient way to convert alkylthiosulfonates, alkylsulfonyl cyanides,
and alkylsulfonyl oxime ethers into the corresponding carbonyl
compounds in high yields via tin-free radical carbonylation. The
present strategy would be further applied to other radical-mediated
carbon–carbon bond forming reactions.
Notes and references
11 (a) S. Kim, I. Y. Lee, J.-Y. Yoon and D.-H. Oh, J. Am. Chem. Soc.,
1996, 118, 5138; (b) S. Kim and J.-Y. Yoon, J. Am. Chem. Soc., 1997,
119, 5982; (c) S. Kim, J.-Y. Yoon and I. Y. Lee, Synlett, 1997, 475; (d)
S. Kim, Adv. Synth. Catal., 2004, 346, 19.
12 The direct conversion of the Barton esters into the corresponding
thiosulfonates was reported previously: D. H. R. Barton, B. Lacher,
B. Misterkiewicz and S. Z. Zard, Tetrahedron, 1988, 44, 1153.
13 (a) M. Kita, M. Watanabe, N. Takada, K. Suenaga, K. Yamada and
D. Uemura, Tetrahedron, 2002, 58, 6405; (b) H. W. Pinnick and
M. A. Reynolds, J. Org. Chem., 1979, 44, 160; (c) J. D.
Macke and L. Field, J. Org. Chem., 1988, 53, 396.
§ Typical procedure for the direct conversion of S-benzyl alkylthiosulfonate
1 into S-benzyl thiol ester 2: Dried heptane (20 ml), S-benzyl
n-butylthiosulfonate (1) (49 mg, 0.2 mmol), and V-40 (15 mg, 0.06 mmol)
were placed in a 50 ml stainless steel autoclave. The autoclave was sealed,
purged three times with 10 atm of CO, pressurized with 50 atm of CO, and
then heated at 120 uC with stirring for 12 h. After excess CO was
discharged at room temperature, the solvent was removed under reduced
pressure. The residue was purified by passing through a silica gel column
using ethyl acetate and n-hexane (1 : 50) as the eluant to give S-benzyl
thiobutanoate (2) (40 mg, 97%).
14 (a) G. H. Coleman, R. W. Leeper and C. C. Schulze, Inorg. Synth.,
1946, 2, 90; (b) M. S. A. Vrijland, Org. Synth., 1977, 57, 88.
15 For reviews on acyl cyanides, see: (a) J. Thesing, D. Witzel and
A. Brehm, Angew. Chem., 1956, 68, 425; (b) S. Hu¨nig and R. Schaller,
Angew. Chem., Int. Ed. Engl., 1982, 21, 36.
16 I. Ryu, H. Kuriyama, S. Minakata, M. Komatsu, J.-Y. Yoon and
S. Kim, J. Am. Chem. Soc., 1999, 121, 12190.
17 I. Ryu, H. Kuriyama, H. Miyazato, S. Minakata, M. Komatsu,
J.-Y. Yoon and S. Kim, Bull. Chem. Soc. Jpn., 2004, 77, 1407.
1 (a) D. P. Curran, in Comprehensive Organic Synthesis, ed. B. M. Trost,
I. Fleming and M. F. Semmelhack, Pergamon, Oxford, 1991, vol. 4,
pp. 715–831; (b) Radicals in Organic Synthesis, ed. P. Renaud and M. P.
Sibi, Wiley-VCH, Weinheim, 2001, vol. 1 and 2.
2 For reviews, see: (a) P. A. Baguley and J. C. Walton, Angew. Chem., Int.
Ed., 1998, 37, 3072; (b) A. Studer and S. Amrein, Synthesis, 2002, 835;
(c) B. Quiclet-Sire and S. Z. Zard, Chem.–Eur. J., 2006, 12, 6002.
3 For our previous reports on tin-free radical reactions: (a) S. Kim and
C. J. Lim, Angew. Chem., Int. Ed., 2004, 43, 5378; (b) S. Kim and
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