O. Yamazaki et al. / Tetrahedron Letters 44 (2003) 8791–8795
8795
5
. (a) Kainz, S.; Luo, Z.; Curran, D. P.; Leitner, W. Synthe-
sis 1998, 1425–1427; (b) Kamiusuki, T.; Monde, T.;
Yano, K.; Yoko, T.; Konakahara, T. Chromatographia
and 1,2-dichloroethane (6 mL). Yields of product were
determined by GC using n-nonane as an internal stan-
dard. FRPSG-supported catalyst was dried under vac-
uum for reuse in the next cycle. Leaching of Sn(IV) and
Hf(IV) in water and 1,2-dichloroethane was analyzed to
be less than 5 ppm by ICP-AES.
1
999, 49, 649–656; (c) Curran, D. P. Synlett 2001, 1488–
1
496; (d) Zhang, Q.; Rivkin, A.; Curran, D. P. J. Am.
Chem. Soc. 2002, 124, 5774–5781; (e) Zhang, W.; Luo, Z.;
Chen, C. H.-T.; Curran, D. P. J. Am. Chem. Soc. 2002,
10. FRPSG-supported (C F SO ) NH (20 mol%) was com-
8
17
2 2
1
24, 10443–10450.
pared with FRPSG-supported Sn[N(SO C F ) ] (5
2 8 17 2 4
6. Tzschucke, C. C.; Markert, C.; Glatz, H.; Bannwarth, W.
mol%) in the reaction of 2-adamantanone using H O2
2
Angew. Chem., Int. Ed. 2002, 41, 4500–4503.
. Into a solution of fluorous Lewis acid (500 mg) in ethanol
(1.1 equiv.). The former was less active (58% yield, 82%
selec.) than the latter (79% yield, 100% selec.). In the
7
(
20 mL), fluorous reverse-phase silica gel (5 g) was added
reaction
(C
48% selec.).
of
F17SO ) NH (4 mol%) was also less active (44% yield,
8 2 2
cyclobutanone,
FRPSG-supported
and the resulting mixture was stirred for 1 h at room
temperature. After removal of the solvent under reduced
pressure, residual FRPSG-supported Lewis acid was
dried under vacuum at 80°C for 6 h.
11. After the work-up of the reaction using standard reverse-
phase silica gel- and normal silica gel-supported
8
. Recent examples of Baeyer–Villiger reaction using H O :
Sn[N(SO C F ) ] , the filtrate was a mixture of an
2 8 17 2 4
2
2
(
a) ten Brink, G.-J.; Vis, J.-M.; Arends, I. W. C. E.;
aqueous solution, an organic solution, and a suspension
containing Sn(IV).
12. Fringuelli, F.; Piermatti, O.; Pizzo, F.; Vaccaro, L. Eur.
J. Org. Chem. 2001, 439–455.
13. Direct esterification catalyzed by Hf(IV) salt: (a) Ishihara,
K.; Ohara, S.; Yamamoto, H. Science 2000, 290, 1140–
1142; (b) Ishihara, K.; Nakayama, M.; Ohara, S.;
Yamamoto, H. Synlett 2001, 1117–1120; direct esterifica-
tion by FBC: (c) Xiang, J.; Orita, A.; Otera, J. Angew.
Chem., Int. Ed. 2002, 41, 4117–4119.
Sheldon, R. A. J. Org. Chem. 2001, 66, 2429–2433; (b)
Corma, A.; Navarro, M. T.; Nemeth, L.; Renz, M. Chem.
Commun. 2001, 2190–2191; (c) Murahashi, S.; Ono, S.;
Imada, Y. Angew. Chem., Int. Ed. 2002, 41, 2366–2368;
(d) Renz, M.; Blasco, T.; Corma, A.; Forn e´ s, V.; Jansen,
R.; Nemeth, L. Chem. Eur. J. 2002, 8, 4708–4717; (e)
Berkessel, A.; Andreae, M. R. M.; Schmickler, H.; Lex, J.
Angew. Chem., Int. Ed. 2002, 41, 4481–4484; (f) Pillai, U.
R.; Sahle-Demessie, E. J. Mol. Cat. A: Chem. 2003, 191,
9
3–100.
14. To a mixture of FRPSG-supported Hf[N(SO C F ) ] (5
2 8 17 2 4
9
. A mixture of 2-adamantanone (0.25 mmol) and FRPSG-
mol%) in 1,2-dichloroethane (1.5 mL), methacrylic acid
(0.5 mmol) and methanol (3 mmol) was added. Reaction
mixture was stirred at 60°C for 16 h. Supported catalyst
was recovered by filtration and washed with 1,2-
dichloroethane (5 mL). Yields of product were deter-
mined by GC using naphthalene as an internal standard.
supported Lewis acid (5 mol%) in 4% aq. H O (2.2 ml)
2
2
was stirred at 25°C for 16 h. After the reaction, 1,2-
dichloroethane (2 mL) was added into the mixture, and
stirred for 10 min, then FRPSG-supported Lewis acid
was recovered by filtration and washed with H O (2 mL)
2