New and efficient iron halide mediated synthesis of alkenyl halides through coupling of alkynes and alcohols

Article abstract of DOI:10.1002/ejoc.200900104

A novel, simple, and straightforward one-pot reaction of alkynes with various alcohols in the presence of iron salts (FeCl₃ and FeBr ₃) was described to yield the corresponding alkenyl halides with complete regioselectivity and high

Full text of DOI:10.1002/ejoc.200900104

FULL PAPER
DOI: 10.1002/ejoc.200900104
New and Efficient Iron Halide Mediated Synthesis of Alkenyl Halides through
Coupling of Alkynes and Alcohols
Srijit Biswas,[a] Sukhendu Maiti,[a] and Umasish Jana*[a]
Keywords: Alkenyl halides / Alkynes / Alcohols / Iron / Sustainable chemistry
A novel, simple, and straightforward one-pot reaction of al-
kynes with various alcohols in the presence of iron salts
(FeCl3 and FeBr3) was described to yield the corresponding
alkenyl halides with complete regioselectivity and high
stereoselectivity. The reaction is high yielding and works un-
der mild conditions. The iron salts act as Lewis acids and a
source of halides. The reaction tolerates a wide variety of
functional groups. Noteworthy is that this method is cheap,
efficient, and environmentally friendly.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2009)
the availability of alkenyl halides is low and they are often
costly. Consequently, the preparation of such compounds is
still challenging and of much interest to synthetic chemists.
Traditionally, vinyl halides are prepared from the corre-
sponding carbonyl compounds with halogenated reagents,[4]
such as phosphorus halides or thionyl halides under pro-
longed heating in high-boiling solvents or by Wittig[5] and
Julia[6] olefination reactions and other related reactions.[7]
Alkynes are another class of compounds used for the syn-
thesis of alkenyl halides, such as the addition of hydrogen
halide and alkyl halides to alkynes in the presence of an
excess amount of ZnCl2.[8] Very recently, Kabalka et al. re-
ported a new strategy to synthesize alkenyl halides by direct
reaction of alkynes and alcohols in the presence of a stoi-
chiometric amount of a strong base such as nBuLi or boron
trichloride.[9] Few of the above-said methods are very useful
for the stereoselective synthesis of alkenyl halides, and most
of these methods are associated with significant practical
drawbacks including nonavailability of the substrates, dras-
tic reaction conditions, long reaction times, use of toxic and
expensive chemicals, multistep reactions, and production of
large amounts of waste throughout the reaction sequences,
which limit their massive applications for industrial pur-
poses. Therefore, development of simple, straightforward,
and environmentally friendly method for the synthesis of
such halogenated derivative represents a highly desirable
goal.
Introduction
Very recently, we disclosed an iron salt catalyzed addition
reaction between aryl alkynes and benzylic alcohols to syn-
thesize aryl ketones.[1] We reported that the course of the
reaction was highly solvent dependent; the product ketone
(A) was only obtained exclusively in nitromethane solvent
in the presence of FeCl3 (15 mol-%), whereas in haloge-
nated solvent, such as dichloromethane, the same reaction
gave only a trace amount of the desired product along with
an alkenyl halide (B) as a major product (Scheme 1). This
observation encouraged us to study systematically the scope
of this new reaction to develop an alternative method for
the synthesis of alkenyl halides.
Scheme 1.
The synthesis of alkenyl and aromatic halides is of great
academic and industrial importance, as they can be easily
converted into other valuable compounds. Moreover, ha-
lides are common structural motifs in organic synthesis for
C–C and C–N bond formation in transition-metal-cata-
lyzed cross-coupling reactions, such as Suzuki–Miyaura,
Stille, Sonogashira, and Buchwald–Hartwig reactions,[2]
and the necessity of these compounds is also increased ac-
cordingly. Alkenyl halides, in particular, are versatile sub-
strates in a variety of chemical transformations;[3] however,
In this regard, the development of a new reaction by
using iron[10] and alcohols[11] has earned much attention in
organic synthesis, as iron is an abundant, economical, and
environmentally friendly metal, and carbon–carbon bond-
formation reactions with the use of alcohols is highly atom
economical and consequently environmentally friendly. In
this context, very recently we[1,12] and others[13] reported the
direct catalytic activation of alcohols by using iron salts for
various useful organic transformations.
[a] Department of Chemistry, Jadavpur University,
Kolkata 700032, West Bengal, India
Fax: +91-33-2414-6584
E-mail: jumasish2004@yahoo.co.in
Supporting information for this article is available on the
WWW under http://www.eurjoc.org or from the author.
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Iron Halide Mediated Synthesis of Alkenyl Halides
Herein, we present our new discovery for the synthesis
The reaction procedure was very simple: a mixture of
of structurally varied alkenyl halides in one pot from al- phenyl acetylene (1 mmol), benzhydrol (1 mmol), and FeCl3
kynes and alcohols in the presence of iron salts under neu- (0.4 mmol) was stirred at room temperature for 1.5 h. The
tral conditions, and in this reaction, the iron salts act as progress of the reaction was followed by TLC. Usual
Lewis acids and a source of halide.[14]
workup and purification gave product 3a as mixture of
E/Z (91:9) isomers in 68% yield. The ratio was calculated
by 1H NMR spectroscopy and compared with the literature
value.[8c,9c]
Results and Discussion
Having optimized the reaction conditions, the scope of
this new reaction was investigated by using various benzylic
alcohols with phenylacetylene. The results are summarized
in Table 2. In general, the reaction proceeded smoothly at
room temperature without removal of air and moisture.
Both electron-rich and weakly electron-deficient benzylic
alcohols reacted under the optimized reaction conditions to
produce the desired products in good yield with complete
regioselectivity (Markovnikov product) and with high E
selectivity. The high regioselectivity may be explained by the
formation of the more stable alkenyl carbocation intermedi-
ate during the addition of the benzylic carbocation onto the
alkyne π bond (Scheme 2), and E selectivity can be ex-
plained from the preferred trans attack of the halide ions to
the alkenyl carbocation. Alcohols that are sensitive towards
acid-catalyzed dehydration can also tolerate the present re-
action conditions (Table 2, Entries 3–8). In all cases, the E
isomers predominated over the Z isomers of the substituted
vinyl chloride derivatives. Notably, propargylic alcohol 2i
reacted smoothly with phenyl acetylene 1a to produce the
corresponding 1-chloro-1,4-enyne 3i in high yield (63%)
and with high selectivity in chloroform solvent (Table 2, En-
try 9). 1-Halo-1,4-eneynes are valuable synthetic intermedi-
ates because of their further synthetic manipulation. 1,4-
Enynes are usually prepared by stoichiometric reaction of
allyl halides with alkyne metal salts or by metal-catalyzed
cross-coupling reactions of allyl halides with alkynes or alk-
ynylborates.[9d,15] Similarly, the reaction of allylic alcohol 2j
with phenylacetylene gave 1-halo-1,4-diene 3j in 46% yield
(Table 2, Entry 10). Functionalized 1,4-pentadienes are very
useful compounds in organic synthesis[16] and biological
systems.[17] However, only few methods are available for the
synthesis of 1,4-pentadienes, such as the cross-coupling of
potassium vinyl trifluoroborates and allyl acetate in the
presence of a palladium catalyst and related reactions.[18]
After having satisfactory results with various alcohols,
we then applied this new protocol for various aromatic ring
substituted alkynes (–Cl, –Br, –NHTs-p, –methyl). The re-
sults are summarized in Table 3. It was observed that the
reaction was quite general with respect to the substituents
of the terminal aromatic alkyne (Table 3, Entries 1–9). Aryl
alkynes bearing weakly electron-withdrawing substituents,
such as –Cl and –Br, reacted smoothly to furnish the de-
sired products in high yield. However, aryl alkynes bearing
strong electron-withdrawing groups, such as nitro, did not
work. Furthermore, aromatic alkyne-bearing electron-do-
nating substituents like –CH3 reacted well and produced the
desired product in satisfactory yield (Table 3, Entry 8). This
reaction was also employed for aliphatic and internal al-
kynes, respectively (Table 3, Entries 10 and 11). Interest-
For optimization of the reaction conditions, we initially
tested the reaction between phenylacetylene (1a) and
benzhydrol (2a) in the presence of varying amounts of an-
hydrous FeCl3 in dichloromethane solvent (Table 1, En-
tries 1–7). The results showed that 40 mol-% FeCl3 was the
optimum amount (Table 1, Entry 5) and desired alkenyl ha-
lide 3a was obtained in 68% in CH2Cl2 at room tempera-
ture. Although the use of a larger amount of FeCl3 reduced
the reaction time, the yield of the product remain un-
changed. The effect of other halogenated solvents, such as
CCl4, 1,2-dichloroethane, and CHCl3, and non-halogenated
solvents, such as benzene, acetone, and acetonitrile, were
also tested. Although halogenated solvents worked ef-
ficiently for this transformation, dichloromethane was
found to be the most effective. Apart from this study, it was
also observed that no reaction took place in the presence of
other metal halides such as FeCl2 and NiCl2·6H2O (Table 1,
Entries 15 and 16), whereas only 26% product was formed
in case of InCl3 (Table 1, Entry 17).
Table 1. Reaction of phenylacetylene (1a) and benzhydrol (2a) with
different Lewis acids (in different amounts) and solvents.[a]
[a] Reaction conditions: 1a (1 mmol), 2a (1 mmol), solvent (3 mL),
Lewis acid (amount as indicated in the table), r.t. [b] Pure, isolated
yield after column chromatography. [c] Ratio calculated by 1H
NMR spectroscopic analysis of the products containing nonsepara-
ble E/Z mixtures.
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S. Biswas, S. Maiti, U. Jana
FULL PAPER
Table 2. Reaction of phenylacetylene (1a) with various alcohols (2) ingly, the formation of the desired products was observed
in the presence of FeCl3.[a]
in both cases. In the case of an internal alkyne, the reaction
proceeded smoothly, producing the corresponding vinyl
chloride in a moderate 45% yield (Table 3, Entry 11),
whereas a lower yield of the desired product was obtained
in the case of an aliphatic alkyne (Table 3, Entry 10).
To explore the generality of iron salts, we investigated
this reaction with FeBr3; in principle, it should give the cor-
responding alkenyl bromides. However, it was observed that
FeBr3 also reacted efficiently under the same reaction con-
ditions (Table 4, Entries 1–9) with various benzylic alcohols
and alkynes and gave the corresponding alkenyl bromides
in moderate to high yield and selectivity. Propargylic
alcohol also reacted smoothly with phenylacetylene in the
presence of FeBr3 to produce the corresponding 1-bromo-
1,4-enyne derivatives in moderate to good yield (Table 4,
Entry 7 and 9) with exclusive formation of the E isomer.
Likewise, 52% yield of the product was obtained in case of
allylic alcohol in chloroform solvent (Table 4, Entry 8). The
reaction of alkynes and alcohols in the presence of FeBr3 is
remarkable, as alkenyl bromide compounds are more popu-
lar in transition-metal-catalyzed cross-coupling reactions.
Except for a few limitations, such as the reaction did not
proceed for nitro-substituted alkynes and alcohols and ali-
phatic alkynes gave lower yields of the desired product, the
reaction is quite general with respect to alcohols and al-
kynes. In general, the reaction is quite efficient, high yield-
ing, and simple, and it can be performed in the presence
of air and moisture at room temperature. A wide range of
functional groups, such as –OMe, –OBn, –NHTs-p, –Cl,
–Br, and double and triple bonds remained unaffected un-
der the reaction conditions.
On the basis of experimental observations, a possible
mechanism of this reaction is proposed in Scheme 2, which
is very similar to our previous mechanism for the synthesis
of aryl ketones.[1] It was observed from our previous work
and reported by others[1,13,19] that in the presence of a cata-
lytic amount of FeCl3, benzylic alcohols were rapidly con-
verted into dimeric ether A by eliminating water. Presum-
[a] Reaction conditions: 1a (1 mmol), 2 (1 mmol), CH2Cl2 (3 mL),
ably, an incipient benzylic carbocation[20] is generated by
anhydrated FeCl3 (0.4 mmol), r.t. for the set period of time.
the complexation of iron salts and ether, followed by nucle-
ophilic attack of the alkyne moiety[21] onto the resulting
benzyl carbocation to generate a more stable alkenyl cation
C and an iron complex B. However, in contrast to our pre-
[b] Pure, isolated yield after column chromatography. [c] Ratio cal-
culated by 1H NMR spectroscopic analysis of the products contain-
ing nonseparable E/Z mixtures. [d] CHCl3 was used in place of
CH2Cl2 to improve the product yield.
Scheme 2. Tentative mechanism for the FeX3-mediated synthesis of alkenyl halides.
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Iron Halide Mediated Synthesis of Alkenyl Halides
Table 3. Reaction of various alkynes 1 with various alcohols 2 in
Table 4. Reaction of various alkynes 1 with various alcohols 2 in
the presence of FeCl3.[a]
the presence of FeBr3.[a]
[a] Reaction conditions: 1a (1 mmol), 2 (1 mmol), CH2Cl2 (3 mL),
FeBr3 (0.4 mmol), r.t. for the set period of time. [b] Pure, isolated
yield after column chromatography. [c] Ratio calculated by 1H
NMR spectroscopic analysis of the products containing nonsepara-
ble E/Z mixtures. [d] CHCl3 was used in place of CH2Cl2 to im-
prove the product yield.
[a] Reaction conditions: 1 (1 mmol), 2 (1 mmol), CH2Cl2 (3 mL),
anhydrated FeCl3 (0.4 mmol), r.t. for the set period of time.
[b] Pure, isolated yield after column chromatography. [c] Ratio cal-
culated by 1H NMR spectroscopic analysis of the products contain-
ing nonseparable E/Z mixtures. [d] 2 mmol alkyne 1f was used.
plex E and iron oxyhalide F reacted successively with al-
kynes and ether for complete conversion of the reactants.
After completion of the reaction, a solid precipitate was
observed in the reaction mixture, which was probably due
to the formation of iron oxyhydroxide. However, in the case
of propargylic and allylic alcohols, formation of ether was
not observed, and possibly the carbocation was generated
directly from the alcohol without formation of ether.
vious mechanism, in this case the ion pairs (alkenyl cation
C and iron complex B) are less stable in dichloromethane
solvent (less polar) in comparison to nitromethane, and
hence, in order to produce stability of the intermediates, the
halide ion of the iron complex immediately reacts with alk-
enyl cation C to give the E/Z mixture of final product D.
Moreover, a mixture of water and dichloromethane is a
heterogeneous system, so the water molecules have less con-
tact with the alkenyl cations. Hence, dichloromethane sol-
vent gave exclusively alkenyl halides. Furthermore, the in-
teraction of halogenated solvent with FeX3 cannot be ruled
Conclusions
In summary, we have developed a novel sequential reac-
out.[22] In this reaction, 40 mol-% of iron salts was sufficient tion of alkynes and alcohols (benzylic, allylic, and propar-
to push the reaction forward, so the intermediate iron com- gylic) in the presence of FeX3 (X = Cl and Br) to synthesize
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S. Biswas, S. Maiti, U. Jana
FULL PAPER
4470; h) E.-I. Negishi, L. Anastasia, Chem. Rev. 2003, 103,
1979–2018.
various substituted vinylic chlorides and bromides, which
represents an excellent complement to the previously re-
ported method by Kabalka et al. and others. In comparison
to recently reported methods[14] our reaction conditions are
more efficient and general, as propargylic and allylic
alcohols also worked under our reaction conditions.
Furthermore, other notable advantages of this method in-
clude operational simplicity (one-pot reaction, without re-
moval of air or moisture), mild reaction conditions (room
temperature), use of inexpensive and nontoxic iron salts,
and direct use of alcohols (highly atom economic). Con-
sidering all these, this method is energy saving and environ-
mentally friendly. In addition, as a result of the availability
of all the starting materials, this reaction may prove very
useful in organic synthesis. Further studies to explore the
reaction mechanism and scope of this reaction are in pro-
gress in our laboratory.
[3]
a) S. P. Stanforth in Comprehensive Organic Functional Group
Transformation II (Eds.: A. R. Katritzky, R. J. K. Taylor), El-
sevier, Oxford 2005, p. 1025; b) A. B. Dounay, L. E. Overman,
Chem. Rev. 2003, 103, 2945–2964; c) M. C. Wills, J. Chauhan,
W. G. Whittingham, Org. Biomol. Chem. 2005, 3, 3094–3095;
d) M. Durandetti, J. Perichon, Synthesis 2004, 3079–3083; e)
M. Mori in Handbook of Organopalladium Chemistry for Or-
ganic Synthesis (Ed.: E. Negishi), Wiley, Hoboken, NJ, 2002,
p. 1213; f) J. Blum, D. Gelman, W. Baidossi, E. Shakh, A. Ro-
senfeld, B. C. Wassermann, M. Frick, B. Heymer, S. Schutte,
S. Wrenik, H. Schumann, J. Org. Chem. 1997, 62, 8681–8686.
a) A. Spaggiari, D. Vaccari, P. Davoli, G. Torre, F. Prati, J. Org.
Chem. 2007, 72, 2216–2219 and references cited therein; b) A.
Lilienkampf, M. P. Johansson, K. Wähälä, Org. Lett. 2003, 5,
3387–3390 and references cited therein; c) J. Kagan, S. K.
Arora, M. Bryzgis, S. N. Dhawan, K. Reid, S. P. Singh, L. Tow,
J. Org. Chem. 1983, 48, 703–706; d) S. Hirsl-Starcevic, Z. Ma-
jerski, J. Org. Chem. 1982, 47, 2520–2525; e) T. Eszenyi, T.
Timar, P. Sebok, Tetrahedron Lett. 1991, 32, 827–828; f) R. S.
Al-awar, S. P. Joseph, D. L. Comins, J. Org. Chem. 1993, 58,
7732–7739.
[4]
[5]
[6]
a) G. Stork, K. Zhao, Tetrahedron Lett. 1989, 30, 2173–2174;
b) D. Seyferth, J. K. Heeren, G. Singh, S. O. Grim, W. B.
Hughes, J. Organomet. Chem. 1966, 5, 267–274; c) D. F. Taber,
R. P. Meagley, D. J. Doren, J. Org. Chem. 1996, 61, 5723–5728;
d) M. Matsumoto, K. Kuroda, Tetrahedron Lett. 1980, 21,
4021–4024; e) R. Batti, D. K. Barma, U. M. Krishna, C. Mios-
kowski, J. R. Falck, Tetrahedron Lett. 1980, 21, 4021–4024.
a) M.-E. Lebrun, P. L. Marquand, C. Berthelette, J. Org. Chem.
2006, 71, 2009–2013; b) S. Surprenant, W. Y. Chan, C. Ber-
thelette, Org. Lett. 2003, 5, 4851–4854.
Experimental Section
Representative Experimental Procedure for the Synthesis of (3-Chlo-
roprop-2-ene-1,1,3-triyl)tribenzene (3a): To a stirred solution of
anhydrated ferric chloride (0.4 mmol) and benzhydrol (2a; 1 mmol)
in dry dichloromethane (3 mL) was added phenylacetylene (1a;
1 mmol). The reaction mixture was stirred vigorously at room tem-
perature, keeping the container tightly closed with a glass stopper.
After completion of the reaction (by TLC), dichloromethane was
evaporated under reduced pressure and the residue was purified by
silica-gel (60–120 mess) column chromatography (petroleum ether)
to afford a mixture of E and Z isomers of desired product 3a (E:Z,
91:9) as a white solid (0.68 mmol, 68%). 1H NMR (300 MHz,
CDCl3): δ = 4.80 (d, J = 11.0 Hz, 1 H, 3a-E, 3-H), 5.44 (d, J =
9.5 Hz, 1 H, 3a-Z, 3-H), 6.47 (d, J = 11.0 Hz, 1 H, 3a-E, 2-H),
6.63 (d, J = 9.5 Hz, 1 H, 3a-Z, 2-H), 7.13–7.38 (m, 15 H, 3a-E,
arom-H; m, 15 H, 3a-Z, arom-H) ppm. 13C NMR (75 MHz,
CDCl3): δ = 50.7, 50.8, 126.7, 128.2, 128.3, 128.4, 128.7, 128.7,
128.9, 129.6, 131.4, 131.5, 136.9, 143.0, 143.4 ppm.[9c]
[7]
[8]
a) W. Su, C. Jin, Org. Lett. 2007, 9, 993–996 and references
cited therein.
a) P. J. Kropp, K. A. Daus, S. D. Crawford, M. W. Tubergen,
K. D. Kepler, S. L. Craig, V. P. Wilson, J. Am. Chem. Soc. 1990,
112, 7433–7434; b) M. Hanack, E. Weber, Chem. Ber. 1983,
116, 777–797; c) H. Mayer, J. L. Gonzalez, K. Luedtke, Chem.
Ber. 1994, 127, 525–531.
a) G. W. Kabalka, M. Yao, S. Borella, Z. Wu, Chem. Commun.
2005, 2492–2494; b) G. W. Kabalka, M. Yao, S. Borella, Z. Wu,
Org. Lett. 2005, 7, 2865–2867; c) G. W. Kabalka, M. Yao, S.
Borella, J. Am. Chem. Soc. 2006, 128, 11320–11321; d) G. W.
Kabalka, Z. Wu, Y. Ju, Org. Lett. 2004, 6, 3929–3931.
For general reviews, see: a) A. Correa, O. G. Mancheno, C.
Bolm, Chem. Soc. Rev. 2008, 37, 1108–1117; b) B. D. Sherry,
A. Früstner, Acc. Chem. Res. 2008, 41, 1500–1511; c) C. Bolm,
J. Legros, J. L. Paih, L. Zani, Chem. Rev. 2004, 104, 6217–6254;
d) A. Früstner, R. Martin, Chem. Lett. 2005, 34, 624–629; e)
D. D. Diaz, P. O. Miranda, J. I. Padrón, V. S. Martin, Curr.
Org. Chem. 2006, 10, 457–476.
For a few recent examples of the catalytic activation of
alcohols, see: a) H. Qin, N. Yamagiwa, S. Matsunga, M. Shiba-
ski, Angew. Chem. Int. Ed. 2007, 46, 409–413; b) S. Shirakawa,
K. Shu, Org. Lett. 2007, 9, 311–314; c) R. Sanz, A. Martínez,
D. Miguel, J. M. Álveraz-Gutiérrez, F. Rodríguez, Adv. Synth.
Catal. 2006, 348, 1841–1845 and references cited therein; d) M.
Yasuda, T. Somyo, A. Baba, Angew. Chem. Int. Ed. 2006, 45,
793–796; e) K. Sonogashira, Y. Inada, Y. Nishibayashi, M. Hi-
dai, S. Uemura, J. Am. Chem. Soc. 2002, 124, 15172–15173.
For the FeCl3-catalyzed activation of alcohols, see: a) U. Jana,
S. Maiti, S. Biswas, Tetrahedron Lett. 2008, 49, 858–862; b) U.
Jana, S. Maiti, S. Biswas, Tetrahedron Lett. 2007, 48, 7160–
7163; c) U. Jana, S. Biswas, S. Maiti, Tetrahedron Lett. 2007,
48, 4065–4069.
[9]
Supporting Information (see footnote on the first page of this arti-
cle): Experimental details and spectroscopic data of all compounds.
[10]
Acknowledgments
We are pleased to acknowledge the financial and infrastructural
assistance from the UGC-CAS programme of the Department of
Chemistry, Jadavpur University. S. B. and S. M. are also thankful
to University Grants Commission (UGC), New Delhi, India and
Jadavpur University, respectively, for their fellowships.
[11]
[1] U. Jana, S. Biswas, S. Maiti, Eur. J. Org. Chem. 2008, 5798–
5800.
[2] a) E. F. Corsico, R. A. Rossi, J. Org. Chem. 2004, 69, 6427–
6432; b) C. R. V. Reddy, S. Urgaonkar, J. G. Verkade, Org. Lett.
2005, 7, 4427–4430; c) K. C. Nicolaou, P. G. Bulger, D. Sarlah,
Angew. Chem. Int. Ed. 2005, 44, 4442–4489; d) recent review on
Stille coupling reactions: P. Espinet, A. M. Echavarren, Angew.
Chem. Int. Ed. 2004, 43, 4704–4734 and references cited
therein; e) S. Kotha, K. Lahiri, D. Kashinath, Tetrahedron
2002, 58, 9633–9695; f) review on Suzuki coupling reactions:
N. Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457–2483; g) K.
Sonogashira, Y. Tohda, N. Hagihara, Synthesis 1975, 16, 4467–
[12]
[13]
a) J. Kischel, K. Mertins, D. Michalik, A. Zapf, M. Beller, Adv.
Synth. Catal. 2007, 349, 865–870; b) Z.-P. Zhan, J.-L. Yu, Y.-
Y. Cui, R.-F. Yang, W.-Z. Yang, J.-P. Li, J. Org. Chem. 2006,
71, 8298–8301; c) I. Iovel, M. Kristin, J. Kischel, A. Zapf, B.
2358
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Iron Halide Mediated Synthesis of Alkenyl Halides
Mathias, Angew. Chem. Int. Ed. 2005, 44, 3913–3917; d) J. Fan,
Z. Wang, Chem. Commun. 2008, 5381–5383.
anaka, M. Kurboshi, T. Hiyama, Tetrahedron Lett. 1995, 36,
1539–1540; h) H. Matsushita, E. Negishi, J. Am. Chem. Soc.
1981, 103, 2882–2884.
[14] During submission of our manuscript, a very similar method
was reported by Liu and co-workers for the synthesis of alkenyl
halides by using direct use of aryl alkynes and benzylic alcohol
in the presence of hydrated FeX3 under heating at 50 °C. Sur-
prisingly, under their reaction conditions the reactions of allylic
alcohol and propargylic alcohol did not work, see: Z.-Q. Liu,
J. Wang, J. Han, Y. Zhao, B. Zhou, Tetrahedron Lett. 2009,
50, 1240–1242; the same author also reported the reaction of
benzylic halides with alkynes in the presence of iron salts for
the synthesis of alkenyl halides, see: Z.-Q. Liu, J. Wang, Y.
Zhao, B. Zhou, Adv. Synth. Catal. 2009, 351, 371–374.
[17] a) S. Durand, J.-L. Parrain, M. Santelli, J. Chem. Soc. Perkin
Trans. 1 2000, 253–273; b) O. Andrey, C. Glanzmann, Y. Land-
ais, L. Parra-Rapado, Tetrahedron 1997, 53, 2835–2854; c)
K. C. Nicolaou, J. Y. Ramphal, N. A. Petasis, C. N. Serhan,
Angew. Chem. Int. Ed. Engl. 1991, 30, 1100–1116.
[18] For the synthesis of 1,4-pentadienes, see: G. W. Kabalka, M.
Al-Masaum, Org. Lett. 2006, 8, 11–13, and references cited
therein.
[19] P. Sabhi, N. Iranpoor, F. K. Behbahani, Tetrahedron 1998, 54,
943–948.
[15] a) L. W. Bieber, M. F. Da Silva, Tetrahedron Lett. 2007, 48,
7088–7090; b) D.-M. Cui, N. Hashimoto, S. Ikeda, Y. Sato, J.
Org. Chem. 1995, 60, 5752–5756; c) T. Jeffery, Tetrahedron Lett.
1989, 30, 2225–2228; d) V. Calo, L. Lopez, G. Marchese, G.
Pesce, Tetrahedron Lett. 1979, 20, 3873–3874; e) H. Chen,
M. Z. Deng, J. Organomet. Chem. 2000, 603, 189–193.
[16] a) D. Basavaiah, D. S. Sharada, N. Kumaragurubaran, R. M.
Reddy, J. Org. Chem. 2002, 67, 7135–7137; b) N. Tsukada, T.
Sato, Y. Inoue, Chem. Commun. 2001, 237–238; c) E. Klaps, W.
Schmid, J. Org. Chem. 1999, 64, 7537–7546; d) R. Hara, Y.
Nishihara, P. D. Landre, T. Takahashi, Tetrahedron Lett. 1997,
38, 447–450; e) A. S. B. Prasad, P. Knochel, Tetrahedron 1997,
53, 16711–16720; f) S. E. Denmark, V. Guagnano, J. A. Dixon,
J. Org. Chem. 1997, 62, 4610–4628; g) H. Matsuhashi, Y. Hat-
[20] For the stability of benzylic cations, see: Y. Liu, S. Zhou, G.
Li, B. Yan, S. Guo, Y. Zhou, H. Zhang, P. Wang, Adv. Synth.
Catal. 2008, 350, 797–801, and references cited therein.
[21] Reaction of alkynes with carbocations: a) F. Marcuzzi, G. Mel-
loni, G. Modena, J. Org. Chem. 1979, 44, 3022–3028 and ref.[8]
;
b) ; D. R. Kell, F. J. Mcquillin, J. Chem. Soc. Perkin Trans. 1
1973, 2100–2103; c) G. V. Roitburd, W. A. Smit, A. V. Se-
menovaky, A. A. Schegolev, V. F. Kucherov, O. S. Chizhov, V. I.
Kadentsev, Tetrahedron Lett. 1972, 13, 4935–4940; d) F. Mar-
cuzzi, G. Modena, J. Org. Chem. 1982, 47, 4577–4579.
[22] P. O. Miranda, R. M. Carballo, M. A. Ramírez, V. S. Martín,
J. I. Padrón, Arkivoc 2007, 4, 331–343.
Received: January 30, 2009
Published Online: April 2, 2009
Eur. J. Org. Chem. 2009, 2354–2359
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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