Angewandte
Chemie
J. M. Fraile, J. I. Garcꢁa, E. Garcꢁa-Verdugo, R. Gonzalez, C. I.
and intramolecular cyclopropanation reactions. Furthermore,
it could be reused even after ten applications and three
months of storage without loss of its catalytic activity and
selectivity. In addition, no significant leaching of the catalyst
was detected. The polymer-supported chiral ruthenium(II)/
pheox catalyst is expected to provide many further oppor-
tunities in asymmetric catalysis. Further investigation is
currently underway to extend this methodology with various
homogeneous catalysts.
1415 – 1418; f) S. S. Lee, J. Y. Ying, J. Mol. Catal. A 2006, 256,
[3] a) T. Tsuji, S. Nishida, S. Patai, The Chemistry of the Cyclopropyl
Group, Wiley, New York, 1987; b) H. N. C. Wong, M.-Y. Hon, C.-
165; c) D. F. Taber, B. M. Trost, I. Fleming, Comprehensive
Organic Synthesis, Vol. 3, Pergammon, New York, 1991, p. 1045;
d) H. M. L. Davies, Comprehensive Asymmetric Synthesis-Sup-
plement 1, Springer, Heidelberg, 2003, pp. 83 – 84 (invited book
935; f) H. Lebel, J.-F. Marcoux, C. M. Molinaro, A. B. Charette,
[4] a) T. Shunji, S. Atsushi, H. Keitaro, J. Cardiovasc. Pharmacol.
Berberich, R. J. Cherney, J. Colucci, C. Courillon, L. S. Geraci ,
T. A. Kirkland, M. A. Marx, M. F. Schneider, S. F. Martin,
[6] a) M. I. Burguete, J. M. Fraile, J. I. Garcꢁa, E. Garcꢁa-Verdugo,
8893 – 8901; b) A. Mandoli, S. Orlandi, D. Pini, P. Salvadori,
[7] a) A. Cornejo, J. M. Fraile, J. I. Garcꢁa, M. J. Gil, S. V. Luis, V.
5544; b) A. Cornejo, J. M. Fraile, J. I. Garcꢁa, M. J. Gil, V.
Experimental Section
General procedure for intermolecular cyclopropanation catalyzed by
4a: The polymer-supported chiral ruthenium(II)/pheox complex 4a
(170.0 mg, 0.018mmol) was evacuated and backfilled with argon and
suspended in CH2Cl2 (3.5 mL). An olefin (1.50 mmol) was injected
through the side-arm via syringe and a toluene solution of EDA
(34.2 mg, 0.30 mmol, ca. 0.2m) was injected through a microsyringe
controlled by mechanical feeder (ca. 0.37 mLhÀ1) over 4 h at 08C.
After stirring for an additional 3 h, the mixture was concentrated
under reduced pressure and the polymeric catalyst was recoverd from
the reaction mixture (centrifugation, washing with n-hexane, diethyl
ether, and acetonitrile, then drying). The combined filtrate which
contains the cyclopropane product was concentrated under reduced
pressure and the residue was purified by column chromatography on
silica gel with n-hexane/EtOAc as an eluent to give the desired
product. The trans/cis ratios were determined from the crude NMR
spectra, and the ee values were determined by GLC or HPLC
analysis.
General procedure for intramolecular cyclopropanation reac-
tions catalyzed by 4a: A solution of allylic diazoacetate in CH2Cl2
(0.1 mmol, ca. 0.1m) was added to a suspension of polymer-supported
ruthenium(II)/pheox complex (4a) (80.0 mg, 0.006 mmol) in CH2Cl2
(2.0 mL) at 08C. After the starting material had completely reacted
(1–4 h), n-hexane (4.0 mL) was added, followed by centrifugation of
the mixture. The product was collected by decantation and the
residue was washed three times with CH2Cl2/n-hexane (1:4 v/v). The
polymer was dried under vacuum before the next cycle. The collected
product was condensed under vaccum and the residue was purified by
column chromatography on silica gel (n-hexane/EtOAc = 10:1) to
afford the corresponding bicyclic lactone. The enantiomeric excesses
of products were determined by HPLC or GC analysis.
[8] For the preparation of homogeneous catalyst 1a, see the
Supporting Information.
[9] For more details about the solvent effect and catalyst loading,
see the Supporting Information.
[10] The SEM images of macroporous (4a) and macroreticular
catalysts (4b; before and after use) are available in the
Supporting Information.
Received: April 15, 2010
Published online: September 22, 2010
[11] a) For discussions of the advantages of the macroporous polymer
over the macroreticular type, see: G. Odian, Principles of
Polymerization, Wiley, New York, 2004, p. 762; b) F. Z. Dꢂr-
wald, Organic Synthesis on Solid Phase, Wiley-VCH, Weinheim,
2000, p. 19.
[12] For details on the reusability of 4a in cyclopropanation of N-
vinylpyrrolidone, see the Supporting Information.
[13] M. P. Doyle, M. A. Mckervey, T. Ye, Modern Catalytic Methods
for Organic Synthesis with Diazo Compounds, Wiley, New York,
1998.
[15] Z.-J. Xu, R. Fang, C. Zhao, J.-S. Huang, G.-Y. Li, N. Zhu, C.-M.
Keywords: asymmetric synthesis · cyclopropanation ·
.
heterogeneous catalysis · ruthenium · supported catalysts
[1] For more details about PSCCs, see: a) E. N. Jacobsen, A. Pfaltz,
H. Yamamoto, Comprehensive Asymmetric Catalysis, Vol. 2,
Springer, Berlin, 1999, pp. 513 – 603; b) D. E. De Vos, I. F. J.
Vankelecom, P. A. Jacobs, Chiral Catalysts Immobilization and
Recycling, Wiley-VCH, Weinheim, 2000; c) Q.-H. Fan, Y.-M. Li,
[2] For recent pubilications in this field, see: a) M. I. Burguete, J. M.
Fraile, J. I. Garcꢁa, E. Garcꢁa-Verdugo, S. V. Luis, J. A. Mayoral,
Angew. Chem. Int. Ed. 2010, 49, 8439 –8443
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
8443