Manganese-catalyzed cross-coupling reaction between aryl grignard reagents and alkenyl halides

Article abstract of DOI:10.1021/ol802273e

(Chemical Equation Presented) Aryl Grignard reagents react stereospecifically with alkenyl halides in the presence of manganese chloride (10%) to afford good yields of cross-coupling products.

Full text of DOI:10.1021/ol802273e

ORGANIC
LETTERS
2008
Vol. 10, No. 22
5255-5256
Manganese-Catalyzed Cross-Coupling
Reaction between Aryl Grignard
Reagents and Alkenyl Halides
Ge´rard Cahiez,* Olivier Gager, and Fabien Lecomte
Department of Chemistry, CNRS - UniVersite´ de Paris13, 74, Rue Marcel Cachin,
F-93017 Bobigny, France
gerard.cahiez@uniV-paris13.fr
Received July 23, 2008
ABSTRACT
Aryl Grignard reagents react stereospecifically with alkenyl halides in the presence of manganese chloride (10%) to afford good yields of
cross-coupling products.
Recently, the use of iron salts to replace palladium or nickel
complexes as catalysts has emerged as a very promising area
for sustainable development. During the past decade, numer-
ous Fe-catalyzed cross-coupling reactions were reported by
us1 and others.2 From both an economical and environmental
point of view, manganese salts are a valuable alternative to
iron salts. However, examples of Mn-catalyzed cross-
coupling reactions are rare.1h,3 Generally, only very reactive
organic halides like activated aryl halides3a-c or
chloroenynes3d have been used until now.
We report herein the first Mn-catalyzed cross-coupling
reactions between aryl Grignard reagents and simple alkenyl
halides. Our first attempts were performed with various
2-bromostyrenes in the presence of 10% MnCl2 (Table 1,
entries 1-7). At room temperature the reaction is slow, but
satisfactory yields were obtained. In some case, it is necessary
to accelerate the reaction by heating at 50 °C (entries 5-7).
Some other reactive alkenyl bromides were coupled under
similar conditions (entries 8-10). The coupling reaction is
always stereospecific (entries 1-7, 9, and 10) except in the
case of the (Z)-3-(2-bromoethenyl)pyridine (entry 8). Sur-
prisingly, a complete inversion of configuration of the double
bond is then observed. As a rule, the slow reaction rate is
(1) Selected references: (a) Cahiez, G.; Marquais, S. Pure Appl. Chem.
1996, 68, 53. (b) Cahiez, G.; Avedissian, H. Synthesis 1998, 1199. (c) Dohle,
W.; Kopp, F.; Cahiez, G.; Knochel, P. Synlett 2001, 1901. (d) Duplais, C.;
Bures, F.; Korn, T.; Sapountzis, I.; Cahiez, G.; Knochel, P. Angew. Chem.,
Int. Ed. 2004, 43, 2968. (e) Cahiez, G.; Chaboche, C.; Mahuteau-Betzer,
F.; Ahr, M. Org. Lett. 2005, 7, 1943. (f) Cahiez, G.; Habiak, V.; Duplais,
C.; Moyeux, A. Angew. Chem., Int. Ed. 2007, 46, 4364. (g) Cahiez, G.;
Duplais, C.; Moyeux, A. Org. Lett. 2007, 9, 3253. (h) Cahiez, G.; Moyeux,
A.; Buendia, J.; Duplais, C. J. Am. Chem. Soc. 2007, 129, 13788.
(2) Selected references: (a) Fu¨rstner, A.; Leitner, A.; Me´ndez, M.;
Krause, H. J. Am. Chem. Soc. 2002, 124, 13856. (b) Fu¨rstner, A.; Leitner,
A. Angew. Chem., Int. Ed. 2002, 41, 609. (c) Nakamura, M.; Matsuo, K.;
Ito, S.; Nakamura, E. J. Am. Chem. Soc. 2004, 126, 3686. (d) Nagano, T.;
Hayashi, T. Org. Lett. 2004, 6, 1297. (e) Bedford, R. B.; Bruce, D. W.;
Frost, R. M.; Goodby, J. W.; Hird, M. Chem. Commun. 2004, 2822. (f)
Martin, R.; Fu¨rstner, A. Angew. Chem., Int. Ed. 2004, 43, 3955. (g) Nagano,
T.; Hayashi, T. Org. Lett. 2005, 7, 491. (h) Bedford, R. B.; Bruce, D. W.;
Frost, R. M.; Hird, M. Chem. Commun. 2005, 4161. (i) Guerinot, A.;
Reymond, S.; Cossy, J. Angew. Chem., Int. Ed. 2007, 46, 6521. (j) Taillefer,
M.; Xia, N.; Ouali, A. Angew. Chem., Int. Ed. 2007, 46, 934. (k)
Hatakeyama, T.; Nakamura, M. J. Am. Chem. Soc. 2007, 129, 9844. See
also: Cahiez, G.; Duplais, C. Iron-Catalyzed Reactions of Grignard Reagents.
In The Chemistry of Organomagnesium Compounds; Rappoport, Z., Marek,
I., Eds.; Wiley VCH: Weinheim, 2008; Chapter 13, p 595.
(3) For Mn-catalyzed reactions of activated aryl halides with RMgX:
(a) Cahiez, G.; Lepifre, F.; Ramiandrasoa, P. Synthesis 1999, 2138. (b)
Cahiez, G.; Luart, D.; Lecomte, F. Org. Lett. 2004, 6, 4395. (c) Rueping,
M.; Ieawsuwan, W. Synlett 2007, 247. For a Mn-catalyzed reaction of RMgX
with 1-chloro-1,3-dienes and 1-chloro-1,3-enynes, see: (d) Alami, M.;
Ramiandrasoa, P.; Cahiez, G. Synlett 1998, 325. (e) For a Mn-catalyzed
reaction with aryl or alkynyltin, see: Kang, S.-K.; Kim, J.-S.; Choi, S.-C.
J. Org. Chem. 1997, 62, 4208. For a Mn-catalyzed reaction with orga-
noalanes, see: (f) Fugami, K.; Oshima, K.; Utimoto, K. Chem. Lett. 1987,
16, 2203. For various Mn-catalyzed homocoupling reactions, see: (g) Cahiez,
G.; Bernard, D.; Normant, J. F. J. Organomet. Chem. 1976, 113, 99. (h)
Kang, S.-K.; Baik, T.-G.; Jiao, X. H.; Lee, Y.-T. Tetrahedron Lett. 1999,
40, 2383.
10.1021/ol802273e CCC: $40.75
Published on Web 10/16/2008
2008 American Chemical Society

Table 1. Mn-Catalyzed Arylation of Alkenyl Halides
a Ratio E/Z determined by GC on the crude product. b GC yield. c ArMgBr was used
probably due to the reductive elimination step. Indeed, Mn(II)
species like Ar2Mn are generally stable at room temperature.4
The reaction was extended to less reactive alkenyl halides
(entries 11-24). Alkenyl bromides and iodides were coupled
successfully (entries 12 and 13); however, the corresponding
chlorides led to poor yields (entry 11). It should be noted
that ꢀ-monosubstituted alkenyl iodides often react at room
temperature (entries 13-20), whereas the less reactive ꢀ,ꢀ-
disubstituted analogues slowly lead to the coupling product
at 50 °C (entries 21-23). The reaction is stereospecific,
except with the R-substituted alkenyl halides (entry 24). It
should be noted that, in some cases, alkyl Grignard reagents
can also be used successfully.5
These results demonstrate the feasibility of Mn-catalyzed
cross-coupling reactions with nonactivated organic halides.
Such reactions could be complementary and/or competitive
to the Fe-catalyzed coupling procedures recently described.1,2
It is important to note that Mn catalysis is an interesting field
of investigation for sustainable development.
Acknowledgment. We thank the CNRS for financial
support, Sanofi Chimie for a grant to F.L., and The Fondation
de France for a grant to O.G.
Supporting Information Available: Detailed experimen-
tal procedures and complete compound characterization data.
This material is available free of charge via the Internet at
http://pubs.acs.org.
In conclusion, we described the first Mn-catalyzed cou-
pling reaction of aryl Grignard reagents with alkenyl halides.
(4) See ref 3h and the Supporting Information.
(5) See the Supporting Information.
OL802273E
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Org. Lett., Vol. 10, No. 22, 2008