Y. Oonishi et al. / Tetrahedron Letters 48 (2007) 7505–7507
7507
+
Table 4. Recycling of IL containing cationic Rh -(R)-BINAP catalyst
2000, 39, 3772; (c) Sheldon, R. Chem. Commun. 2001, 2399;
d) Wilkes, J. S. Green Chem. 2002, 4, 73; (e) Dupont, J.; de
Souza, R. F.; Suarez, P. A. Z. Chem. Rev. 2002, 102, 3667;
(f) Ionic Liquids in Synthesis; Wasserscheid, P., Welton, T.,
Eds.; Wiley-VCH: Weinheim, 2003; (g) Welton, T. Coord.
Chem. Rev. 2004, 248, 2459.
(
O
O
1
mol%
[Rh(
R-BINAP)]ClO4
H
∗
[BMI][NTf2]
rt, 1-5 h
1
d
(
S
)-2d
2
. For pioneering work on Rh(I)-catalyzed reactions in ILs,
see: (a) Chauvin, Y.; Mussmann, L.; Olivier, H. Angew.
Chem., Int. Ed. Engl. 1995, 34, 2698; (b) Suarez, P. A. Z.;
Dullius, J. E. L.; Einloft, S.; de Sousa, R. F.; Dupont, J.
Polyhedron 1996, 15, 1217.
3. For a pioneering work on Rh(I)-mediated hydroacylation
of 4-alkenal, see: Sakai, K.; Ide, J.; Oda, O.; Nakamura, N.
Tetrahedron Lett. 1972, 1287.
Cycle
1
2
3
4
5
Yield (%)
ee (%)
>99
99
>99
99
>99
99
99
99
99
99
a
a
Ee was determined by HPLC.
4
. For examples of Rh(I)-catalyzed intramolecular hydroacy-
lation of 4-alkenals, see: (a) Lochow, C. F.; Miller, R. G. J.
Am. Chem. Soc. 1976, 98, 1281; (b) Larock, R. C.; Oertle,
K.; Potter, G. F. J. Am. Chem. Soc. 1980, 102, 190; (c)
Sakai, K.; Ishiguro, Y.; Funakoshi, K.; Ueno, K.; Sue-
mune, H. Tetrahedron Lett. 1984, 25, 961; (d) Fairlie, D. P.;
Bosnich, B. Organometallics 1988, 7, 936; For examples of
Rh(I)-catalyzed asymmetric hydroacylation of 4-alkenals,
see: (e) James, B. R.; Young, C. G. J. Chem. Soc., Chem.
Commun. 1983, 1215; (f) James, B. R.; Young, C. G. J.
Organomet. Chem. 1985, 285, 321; (g) Taura, Y.; Tanaka,
M.; Funakoshi, K.; Sakai, K. Tetrahedron Lett. 1989, 30,
In summary, we have succeeded in developing Rh(I)-cat-
alyzed hydroacylation using ILs as reaction media for
the first time. It has been proven that the IL recovered
after the reaction could be used repeatedly without a sig-
nificant decrease in either catalytic activity or enantio-
selectivity (in the case of asymmetric hydroacylation).
These results indicate that the cationic [Rh(dppe)] cata-
lyst can be immobilized in ILs via ionic interactions.
Further studies along this line are in progress.
6
349; (h) Tanaka, M.; Imai, M.; Fujio, M.; Sakamoto, E.;
Acknowledgements
Takahashi, M.; Eto-Kato, Y.; Wu, X. M.; Funakoshi, K.;
Sakai, K.; Suemune, H. J. Org. Chem. 2000, 65, 5806; (i)
Tanaka, M.; Sakai, K.; Suemune, H. Curr. Org. Chem.
This work was financially supported by Grant-in-Aid
for Scientific Research on Priority Areas (No.
2
003, 7, 353; (j) Barnhart, R. W.; Wang, X.; Noheda, P.;
1
8032003, ‘Creation of Biologically Functional Mole-
Bergens, S. H.; Whelan, J.; Bosnich, B. J. Am. Chem. Soc.
1994, 116, 1821; (k) Barnhart, R. W.; Bosnich, B. Organo-
metallics 1995, 14, 4343; (l) Bosnich, B. Acc. Chem. Res.
cules’) from the Ministry of Education, Culture, Sports,
Science, and Technology, Japan, and by Grant-in-Aid
for Scientific Research (B) (No. 19390001) from the
Japan Society for the Promotion of Sciences (JSPS).
1
998, 31, 667; (m) Kundu, K.; McCullagh, J. V.; Morehead,
A. T., Jr. J. Am. Chem. Soc. 2005, 127, 16042, and
references cited therein.
5
6
. For a review see: Modern Rhodium-Catalyzed Organic
Reactions; Evans, P. A., Ed.; Wiley-VHC: Weinheim, 2005.
. For preparation of ILs, see: (a) Huddleston, J. G.; Visser,
A. E.; Reichert, W. M.; Willauer, H. D.; Broker, G. A.;
Rogers, R. D. Green Chem. 2001, 3, 156; (b) Dupont, J.;
Consorti, C. S.; Suarez, P. A. Z.; de Souza, R. F. Org.
Synth. 2002, 79, 236.
Supplementary data
7
8
. (a) Sato, Y.; Oonishi, Y.; Mori, M. Angew. Chem., Int. Ed.
2
002, 41, 1218; (b) Oonishi, Y.; Mori, M.; Sato, Y.
Synthesis 2007, 2323.
. Rh(I)-catalyzed asymmetric hydroacylation of 1d in
References and notes
CH
2 2 4
Cl using [Rh(R)-BINAP]ClO catalyst has been
1
. For reviews see: (a) Welton, T. Chem. Rev. 1999, 99, 2071;
b) Wasserscheid, P.; Keim, W. Angew. Chem., Int. Ed.
reported. See Ref. 4m.
(