ORGANIC
LETTERS
2005
Vol. 7, No. 26
5893-5895
Room-Temperature Cannizzaro Reaction
under Mild Conditions Facilitated by
Magnesium Bromide Ethyl Etherate and
Triethylamine†
M. Saeed Abaee,* Roholah Sharifi, and Mohammad M. Mojtahedi
Organic Chemistry Laboratory, Chemistry & Chemical Engineering Research Center
of Iran, P.O. Box 14335-186, Tehran, Iran
Received October 17, 2005
ABSTRACT
A room-temperature convenient Cannizzaro reaction prompted by magnesium bromide ethyl etherate and triethylamine is described for smooth
conversion of aromatic aldehydes into their respective alcohols and carboxylic acids. The methodology is applicable to both inter- and
intramolecular reactions and could be directed to obtain the carboxylic moiety in the form of an acid, an amide, or an ester compound
depending on the selected reaction conditions or workup procedure.
The redox disproportionative conversion of aldehydes into
their corresponding alcohols and carboxylic acids, known
as Cannizzaro reaction,1 is one of the oldest processes in
synthetic organic chemistry and is classicaly conducted at
elevated temperatures using equimolar or excessive amounts
of alkali metal hydroxides or other strong bases. Such harsh
conditions and competitive formation of undesired side
products have been the main limitations for Cannizzaro
reaction in the past several decades.2 Many developments
have been made to the original version of the reaction in
the past several years by means of microwave irradiation,3
ultrasound mediation,4 cation templates,5 solid-supported
reagents,6 solvent-free conditions,7 crossed Cannizzaro ver-
sion of the reaction,3b,6 gas-phase process,8 photo induction,9
and Lewis acid catalysis.10 Despite all of these modifications,
the reaction still requires drastic conditions in most cases.
In a few examples conducted at room temperature, strong
basic media are still required7 or yields of the majority of
the reactions are rather low or moderate.10c During our recent
studies on Lewis acid catalyzed aldol reactions of hetero-
cyclic ketones,11 we realized that in the presence of mag-
nesium bromide ethyl etherate (MgBr2‚OEt2) aromatic
(5) Vida, Y.; Perez-Inestrosa, E.; Suau, R. Tetrahedron Lett. 2005, 46,
1575-1577.
(6) Reddy, B. V. S.; Srinivas, R.; Yadav, J. S.; Ramalingam, T. Synth.
Commun. 2002, 32, 219-223.
† Dedicated to Professor Dale E. Ward.
(1) (a) Cannizzaro, S. Ann. 1853, 88, 129. (b) Geissman, T. A. Org.
React. 1944, 2, 94-113.
(2) (a) Fuson, R. C.; Emerson, W. S.; Gray, H. W. J. Am. Chem. Soc.
1939, 61, 480-482. (b) Maruyama, K.; Murakami, Y.; Yoda, K.; Mashino,
T.; Nishinaga, A. J. Chem. Soc., Chem. Commun. 1992, 1617-1618. (c)
Jin, S. J.; Arora, P. K.; Sayre, L. M. J. Org. Chem. 1990, 55, 3011-3018.
(d) Okuyama, T.; Kimura, K.; Fueno, T. Bull. Chem. Soc. Jpn. 1982, 55,
2285-2286.
(3) (a) Sharifi, A.; Mojtahedi, M. M.; Saidi, M. R. Tetrahedron Lett.
1999, 40, 1179-1180. (b) Varma, R. S.; Naicker, K. P.; Liesen, P. J.
Tetrahedron Lett. 1998, 39, 8437-8440.
(4) Entezari, M. H.; Shameli, A. A. Ultrason. Sonochem. 2000, 7, 169-
172.
(7) Yoshizawa, K.; Toyota, S.; Toda, F. Tetrahedron Lett. 2001, 42,
7983-7985.
(8) Sheldon, J. C.; Bowie, J. H.; Dua, S.; Smith, J. D.; O’Hair, R. A. J.
J. Org. Chem. 1997, 62, 3931-3937.
(9) Kagan, J. Tetrahedron Lett. 1966, 7, 6097-6102.
(10) (a) Curini, M.; Epifano, F.; Genovese, S.; Marcotullio, M. C.; Rosati,
O. Org. Lett. 2005, 7, 1331-1333. (b) Kim, B. T.; Cho, C. S.; Kim, T. J.;
Shim, S. C. J. Chem. Res. 2003, 368-369. (c) Russell, A. E.; Miller, S. P.;
Morken, J. P. J. Org. Chem. 2000, 65, 8381-8383. (d) Yang, X. G.; Guo,
J. P.; Zou, G. Lett. Org. Chem. 2005, 2, 145-147.
(11) (a) Abaee, M. S.; Mojtahedi, M. M.; Zahedi, M. M. Synlett 2005,
2317-2320. (b) Abaee, M. S.; Mojtahedi, M. M.; Zahedi, M. M.;
Bolourtchian, M. Synth. Commun. 2006, 36, 199-206.
10.1021/ol052506y CCC: $30.25
© 2005 American Chemical Society
Published on Web 12/01/2005