Iodine-initiated domino reaction of hepta-1,2-dien-6-yn-4-ols and bronsted acid promoted cyclization of hepta-1,2,6-trien-4-ols leading to functionalized benzenes

Article abstract of DOI:10.1002/asia.201201151

Buy one get one free: Concurrent introduction of both iodo- and carbonyl groups, along with the construction of the benzenoid core, has been achieved through an iodine-initiated domino reaction of hepta-1,2-dien-6-yn-4-ols. Moreover, cyclization of hepta-1,2,6-trien-4-ols turns out to also be an efficient pathway toward diversely substituted benzenes. Copyright

Full text of DOI:10.1002/asia.201201151

COMMUNICATION
DOI: 10.1002/asia.201201151
Iodine-Initiated Domino Reaction of Hepta-1,2-dien-6-yn-4-ols and Brønsted
Acid Promoted Cyclization of Hepta-1,2,6-trien-4-ols Leading to
Functionalized Benzenes
Yan He, Xin-Ying Zhang,* Liang-Yan Cui, and Xue-Sen Fan*[a]
Functionalized benzenes, in particular, carbonyl- or iodo-
substituted benzenes, are attractive synthetic targets as they
are not only commmon structural units in natural products
and pharmaceuticals, but also among the most commonly
used precursors in organic synthesis.[1] While direct function-
Scheme 1. Proposed cycloaromatization of hepta-1,2-dien-6-yn-4-ol.
alization of aromatic starting materials is often used to pre-
pare the required functionalized benzenes, construction of
aromatic rings from the easily obtainable acyclic units con-
To check the feasibility of the above proposal, 4-phenyl-
hepta-1,2-dien-6-yn-4-ol (2a)[6] was prepared from 1-phenyl-
buta-2,3-dien-1-one (1a) and propargyl bromide under the
promotion of zinc and was then treated with H2SO4 in
CH2Cl2 (Scheme 2) under reflux. To our disappointment, the
stitutes another efficient way for this purpose.[2]
Cycloaromatization of enyne–allenes through a radical in-
termediate, known as the Myers–Saito cyclization, is docu-
mented as an efficient method for the preparation of benze-
noid compounds.[3] However, the utility of this strategy is
compromised as the enyne–allene precursors are usually ob-
tained through multi-step processes that employ expensive
catalysts and reagents, or generated in situ through noble
transition-metal-catalyzed sigmatropic rearrangement of
propargylic acetates or propargyl vinyl ethers.[3,4]
In our recent study on the chemistry of allene deriva-
tives,[5] we have developed a synthetic approach toward 2H-
pyran-2-ones through the tandem reaction of 3-hydroxy-
hexa-4,5-allenic esters.[5c] The reaction is thought to be initi-
ated by an acid-promoted dehydration of the tertiary alco-
hol followed by hydration of the allene moiety and an intra-
molecular esterification of the in situ formed enol unit.
In light of the high efficiency and mild conditions in-
volved in the above-mentioned process, we hypothesized
that an acidic promoter might trigger the Myers–Saito pro-
cess through dehydration of hepta-1,2-dien-6-yn-4-ol to give
the required hepta-1,2,4-trien-6-yne. Subsequent cycloaro-
matization of the enyne–allene intermediate would afford
a biradical intermediate, from which a meta-substituted tolu-
ene molecule is supposed to be formed (Scheme 1).
Scheme 2. Unexpected formation of 3a from 2a.
reaction afforded a complicated mixture of compounds, in-
stead of the expected 3-methylbiphenyl. Based on the obser-
vations made by Hibbert et al. that iodine is highly efficient
in promoting the dehydration of tertiary alcohols,[7] 2a was
then treated with I2 (1 equiv) in CH2Cl2 at reflux for 10 h.
Surprisingly, 5-iodo-biphenyl-3-carbaldehyde (3a), instead
of the expected 3-methylbiphenyl, was obtained in a yield of
36% (Scheme 2).
The unexpected formation of 3a turns out to be a syntheti-
cally useful and mechanistically attractive finding as it not
only reveals a novel iodine-initiated cyclization, but also
provides an unprecedented protocol for the one-pot intro-
duction of two valuable functional groups, namely, iodo and
formyl, onto the benzene ring along with the construction of
the benzenoid core.
[a] Y. He, Prof. Dr. X.-Y. Zhang, L.-Y. Cui, Prof. Dr. X.-S. Fan
School of Chemistry and Environmental Science
Key Laboratory for Yellow River and Huai River Water Environ-
ment and Pollution Control
Key Laboratory of Green Chemical Media and Reactions
Ministry of Education, Henan Normal University
46 Jianshe Road, Xinxiang, Henan 453007 (P. R. China)
Fax : (+86)373-332-6336
To develop the above reaction into a new synthetic path-
way toward iodobenzaldehyde, we proceeded to optimize
the reaction conditions. The effect of solvent on this tandem
reaction was studied first. It turned out that CH3CN gave
the best results (Table 1, entries 1–6). Different reaction
temperatures and amounts of iodine were also tested
E-mail: xuesen.fan@htu.cn
xinyingzhang@htu.cn
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201201151.
Chem. Asian J. 2013, 8, 717 – 722
717
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Xin-Ying Zhang, Xue-Sen Fan et al.
Table 1. Optimization studies for the synthesis of 3a.[a]
Table 2. Synthesis of iodobenzaldehydes (3).[a]
Entry
Solvent
I2 [equiv]
T [8C]
t [h]
Yield [%][b]
Entry
R1
R2
3
Yield [%][b]
1
2
3
4
5
6
7
8
CH2Cl2
Toluene
DMF
CH3CN
EtOH
1
1
1
1
1
1
0.2
0.5
2
reflux
60
60
60
60
60
60
60
60
10
10
10
10
10
10
12
12
5
36
40
28
60
trace
25
26
51
61
1
2
3
4
5
6
7
8
Ph
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
CH3
CH3
CH3
CH3
CH3
C2H5
H
3a
3b
3c
3d
3e
3 f
3g
3h
3i
3j
3k
3l
3m
3n
3o
3p
3q
3r
75
62
64
81
80
77
82
66
72
70
74
66
65
68
70
65
59
63
64
62
58
48
45
38
p-CH3O-C6H4
p-CH3-C6H4
p-F-C6H4
H2O
p-Cl-C6H4
p-Br-C6H4
p-NC-C6H4
m-CH3-C6H4
m-F-C6H4
m-Cl-C6H4
m-Br-C6H4
o-F-C6H4
o-Cl-C6H4
m,p-di-CH3O-C6H3
2-naphthyl
p-CH3O-C6H4
p-CH3-C6H4
p-Br-C6H4
p-Cl-C6H4
m-Cl-C6H4
o-Cl-C6H4
PhCH2
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
9
10
11
12
1
1
1
r.t.
40
reflux
10
10
10
trace
43
75
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
[a] Reaction conditions: 2a (0.5 mmol), solvent (5 mL); [b] Yield of iso-
lated product.
(Table 1, entries 7–12). After exhaustive studies, the optimal
reaction conditions were identified as follows: treating 2a
with 1 equivalent of I2 in CH3CN at reflux under air for 10 h
afforded 3a in 75% yield.
3s
3t
3u
3v
3w
3x
With the optimized conditions in hand, we screened
a range of hepta-1,2-dien-6-yn-4-ols (2) to probe the scope
of the present reaction (Table 2). It turns out that substrates
derived from aryl-substituted allenic ketones with various
substituents on the aryl ring undergo this reaction smoothly
in good to excellent yields (Table 2, entries 1–15). Various
functional groups, such as electron-rich methoxy and elec-
tron-deficient cyano groups, are well tolerated under the re-
action conditions. Interestingly, using substrates with
a methyl or ethyl group at the internal position of the allene
moiety, also results in a smooth transformation to afford the
corresponding 3-iodobenzaldehydes efficiently (Table 2, en-
tries 16–21). Moreover, the reaction is also found to be com-
patible with substrates prepared from benzyl- or phenyleth-
yl-substituted allenic ketones, although the yields are some-
what lower (Table 2, entries 22–24). The molecular structure
of the representative product 3 f was determined by X-ray
crystallographic analysis.[8]
PhCH2
PhCH2CH2
CH3
H
[a] Reaction conditions: 2 (1 mmol), I2 (1 mmol), CH3CN (5 mL), reflux,
10 h; [b] Yield of isolated product.
Scheme 3. Plausible pathway for the formation of 3 from 2.
Based on the above observations and related literature
procedures, it is reasoned that the role played by I2 in this
tandem process is not only promoting the dehydration of
the tertiary alcohol, but also initiating the subsequent cycli-
zation of the in situ formed enyne–allene intermediate.
Therefore, a plausible pathway for the formation of iodo-
benzaldehyde (3) is proposed, as shown in Scheme 3. Initial-
ly, I2-promoted dehydration of 2 through a carbocation (I)
affords an enyne–allene intermediate (II).[9] Subsequently,
coordination of I2 to the carbon–carbon triple bond in II af-
fords an iodonium intermediate (III), which then undergoes
a nucleophilic attack on the allenyl moiety to give a benzyl
cation (IV).[10] Trapping of IV by iodide would afford 3-io-
dobenzyl iodide (V).[11] Oxidation of V by air affords 3 as
the final product.[12]
The proposed mechanism for the formation of 3 is sup-
ported by the following facts: 1) when 2 was treated with I2
under a nitrogen atmosphere, the reaction mainly gave 3-io-
dobenzyl iodide (V) instead of 3; 2) 3-iodobenzyl iodide (V)
could be isolated from the reaction mixture and its structure
was confirmed by X-ray diffraction analysis;[13] 3) when the
solution of V in CH3CN was refluxed under air for several
hours, V could be transformed into 3 in high efficiency
(Scheme 4).
Scheme 4. Formation and transformation of intermediate V.
Chem. Asian J. 2013, 8, 717 – 722
718
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Xin-Ying Zhang, Xue-Sen Fan et al.
To further explore the scope of the above reaction, 1,4-di-
phenylhepta-1,2-dien-6-yn-4-ol (2y), bearing a phenyl group
at the terminal position of the allene moiety, was employed.
It turned out that an iodobenzophenone, (5-iodobiphenyl-3-
than the proposed benzyl cation (E) that is required for the
formation of 3-iodo-2,5-diphenylbenzaldehyde owing to
both electronic and steric reasons. As a result, instead of
going through intermediate E to give 3-iodo-2,5-diphenyl
benzaldehyde, under the reaction conditions, 2z would un-
dergo a tandem process via intermediate B to afford 4a.
Next, a series of hepta-1,2-dien-6-yn-4-ols with a phenyl,
methyl, or ethyl group at the terminal position of the triple
bond were prepared and treated with I2 in CH3CN with the
aim to develop the reaction shown in Scheme 6 into a gener-
al synthetic method toward iodoaryl ketones. It turned out
that all the substrates studied underwent the tandem process
smoothly to give the corresponding iodo-substituted diaryl
ketones (Table 3, entries 1 and 2), aryl methyl ketones
yl)
ACHTUNGTRENNUNG(phenyl) methanone (4a), could be obtained in a yield of
42%. 4a is supposed to be formed through an allene–enyne
(A) and
a diphenyl methyl cation (B), as shown in
Scheme 5.
Table 3. Synthesis of iodoarylketones (4).[a]
Scheme 5. Plausible pathway for the formation of 4a from 2y.
In the following study, the reaction of 4,7-diphenylhepta-
1,2-dien-6-yn-4-ol (2z), with a phenyl group at the terminal
position of the alkyne moiety, was also investigated. Upon
treatment with iodine, to our surprise, it still gave 4a rather
Entry
R1
R2
R3
4
Yield [%][b]
1
2
3
4
5
6
7
8
C6H5
p-CF3-C6H4
C6H5
H
H
H
H
H
H
H
H
H
H
H
CH3
C6H5
C6H5
CH3
CH3
CH3
CH3
CH3
CH3
CH3
C2H5
C2H5
CH3
4a
4b
4c
4d
4e
4 f
4g
4h
4i
68
70
52
55
50
58
62
51
63
45
55
51
than
the
expected
3-iodo-2,5-diphenylbenzaldehyde
m-Cl-C6H4
m-Br-C6H4
p-Cl-C6H4
p-Br-C6H4
p-CH3-C6H4
p-CF3-C6H4
o-Cl-C6H4
p-CF3-C6H4
C6H5
(Scheme 6).
9
10
11
12
4j
4k
4l
[a] Reaction conditions: 2 (0.5 mmol), I2 (0.5 mmol), CH3CN (5 mL),
reflux, 10 h; [b] Yield of isolated product.
Scheme 6. Unexpected formation of 4a from 2z.
This interesting result might be explained by a plausible
pathway as shown in Scheme 7. It is assumed that the inter-
nal alkynyl moiety of enyne–allene D is less reactive than
the allenic moiety towards iodine. Therefore, the cyclization
is initiated by the coordination of iodine to allene rather
than to the alkyne. Subsequent cyclization affords a diphenyl
methyl cation intermediate (B), which is far more stable
(Table 3, entries 3–9), as well as aryl ethyl ketones (Table 3,
entries 10 and 11) in moderate to good yields. It is noted
that the reaction is also compatible with substrates that bear
a methyl group at the internal position of the allene moiety
(Table 3, entry 12).
Having explored the reactivity of hepta-1,2-dien-6-yn-4-ol
(2), our attention moved to its allyl counterpart, hepta-1,2,6-
trien-4-ol (5). We found that 4-
phenylhepta-1,2,6-trien-4-ol
(5a) could be prepared through
a zinc-promoted reaction of 1a
with allyl bromide; when treat-
ed with I2 in CH3CN, it gave an
unidentifiable mixture of com-
pounds. On the other hand,
treatment of 5a with H2SO4 in
CH3CN at room temperature
for 2 h afforded 3-methylbi-
phenyl (6a) in a yield of 46%
(Scheme 8).
Scheme 7. Plausible pathway for the formation of 4a from 2z.
Chem. Asian J. 2013, 8, 717 – 722
719
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Xin-Ying Zhang, Xue-Sen Fan et al.
zation studies, 6a could be obtained in 81% yield when the
reaction was carried out in CH2Cl2 at room temperature for
0.2 h in the presence of 1 equivalent of H2SO4 (Table 4,
entry 5).
Based on the above results, the scope and generality of
the reaction that leads to 6 was studied. For most of the
hepta-1,2,6-trien-4-ols (5) studied, the reactions proceeded
smoothly to afford 1,3-disubstituted benzenes in good yields
(Table 5, entries 1–16). It is noted that substrates with elec-
Scheme 8. Formation of 6a through H2SO4 promoted cyclization of 5a.
Table 5. Synthesis of substituted benzenes (6).[a]
Scheme 9. Plausible pathway for the formation of 6a.
Mechanistically, the formation of 6a is thought to involve
an electrocyclization process of a diene–allene intermediate,
which must be formed in situ through an acid-promoted de-
hydration of 5a (Scheme 9).
Pioneering works have proven that the 6p-electrocycliza-
tion of diene–allenes is an efficient protocol for the con-
struction of the benzene ring.[14] However, the main chal-
lenge in employing this strategy to prepare substituted ben-
zenes is how to obtain the required diene–allene intermedi-
ates. While isomerization of propargyl diene is an elegant
approach toward diene–allenes,[15] dehydration of the readily
available hepta-1,2,6-trien-4-ol (5) as described above pro-
vides another good solution to this problem.
Entry R1
R2
R3
R4
R5
6
Yield [%][b]
1
C6H5
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
CH3
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
CH3
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
CH3
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
6a
6b
6c
6d
6e
6 f
6g
6h
6i
81
85
84
82
72
79
78
75
45
70
88
86
2
o-F-C6H4
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
o-Cl-C6H4
o-Br-C6H4
m-CH3-C6H4
m-F-C6H4
m-Cl-C6H4
m-Br-C6H4
p-CH3O-C6H4
p-CH3-C6H4
p-F-C6H4
p-Cl-C6H4
p-Br-C6H4
p-NC-C6H4
p-CF3-C6H4
2-naphthyl
p-Cl-C6H4
p-CH3-C6H4
C6H5
6j
6k
6l
6m 85
6n
6o
6p
6q
6r
90
86
53
83
68
80
75
Afterwards, the reaction of 5a towards 6a was optimized
by employing different solvents and catalysts (Table 4). Ini-
Table 4. Optimization studies for the formation of 6a.[a]
CH3 6s
H 6t
o-Br-C6H4
[a] Reaction conditions: 5 (1 mmol), H2SO4 (1 mmol), CH2Cl2 (5 mL), rt,
0.2 h; [b] Yield of isolated product.
Entry
Acid
Solvent
t [h]
Yield [%][b]
tron-deficient substituents on the phenyl ring usually give
the corresponding products in higher yields (Table 5, en-
tries 2–4, and 11–15) than those with electron-rich substitu-
ents (Table 5, entries 9, 10, and 16). 3-ethylbiphenyl was ob-
tained by employing a substrate that posseses a methyl
group at the terminal position of the allene moiety (Table 5,
entry 17). Moreover, for substrates with a methyl group at
the terminal or the inner position of the vinyl moiety, or at
the internal position of the allene moiety, 1,3,4-, 1,3,5-, or
1,2,3-trisubstituted benzene derivatives could be synthesized
with high efficiency (Table 5, entries 18–20), thus making
this reaction a versatile pathway toward diversely substitut-
ed benzenes.
1
2
3
4
5
6
7
8
H2SO4
H2SO4
H2SO4
H2SO4
H2SO4
TsOH
CF3CO2H
CH3CO2H
CCl3CO2H
H2SO4 (0.2 equiv)
H2SO4 (0.5 equiv)
CH3CN
C2H5OH
Et2O
2
2
2
2
0.2
5
5
5
5
46
trace
trace
25
81
35
45
trace
30
22
54
THF
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
9
10
11
6
6
[a] Reaction conditions: 5a (0.5 mmol), solvent (5 mL), acid (0.5 mmol),
rt; [b] Yield of isolated product.
tially, it was found that the solvent affects the outcome of
this reaction significantly. Among the solvents studied,
CH2Cl2 is the most effective. With CH2Cl2 as a medium,
other Brønsted acids such as TsOH, CF3COOH, and
CCl3COOH were also tried but they were less effective than
H2SO4 in promoting this reaction. In summary of the optimi-
Finally, the versatile transformation and valuable synthet-
ic applications of iodobenzaldehyde (3) was explored and
the results are demonstrated in Scheme 10. While keeping
the iodo group intact, the carbonyl group could be conven-
iently transformed into a cyano, allenic ketone, furan, or al-
cohol unit. On the other hand, the iodo group could be used
Chem. Asian J. 2013, 8, 717 – 722
720
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Xin-Ying Zhang, Xue-Sen Fan et al.
ethyl acetate/hexanes (1:20–1:5) as the eluent to give 5-iodobiphenyl-3-
carbaldehyde (3a, 75%). 3b–3x were obtained in a similar manner.
Typical procedure for the preparation of (5-iodobiphenyl-3-yl)ACHTNUTGRNEUNG(phenyl)
methanone (4a)
I2 (0.5 mmol) was added to a flask containing 4,7-diphenylhepta-1,2-dien-
6-yn-4-ol (2z, 0.5 mmol) in CH3CN (5 mL). The solution was stirred
under reflux. Upon completion, the mixture was concentrated under
vacuum. The residue was purified by column chromatography on silica
gel using ethyl acetate/hexanes (1:20–1:5) as the eluent to give (5-iodobi-
phenyl-3-yl)
ACHTUNGTREN(NUGN phenyl)methanone (4a, 68%). 4b–4l were obtained in a sim-
ilar manner.
Typical procedure for the preparation of 3-methylbiphenyl (6a)
H2SO4 (1 mmol) was added to a flask containing 4-phenyl-hepta-1,2,6-
trien-4-ol (5a, 1 mmol) in CH2Cl2 (5 mL). The solution was stirred at
room temperature. Upon completion, the reaction was quenched with
aqueous Na2CO3. The mixture was extracted with ethyl acetate (5 mLꢁ
3). The combined organic phases were dried, filtered, and concentrated
under vacuum. The residue was purified by column chromatography on
silica gel using ethyl acetate/hexanes (1:80) as the eluent to give 3-meth-
ylbiphenyl (6a, 81%). 6b–6t were obtained in a similar manner.
Scheme 10. Versatile transformations and synthetic applications of 3.[a,b]
[a] R=C6H5, or 4-NCC6H4. [b] Reagents and conditions: a) NH2OH·HCl,
NaOAc, THF/H2O (10:3), rt, 1 h; b) POCl3, CH3CN, rt, 1 h; c) 3-bromo-
prop-1-yne, Zn, THF/DMF, rt, 0.5 h; d) Jones reagent, acetone, 08C,
5 min; e) AgNO3, CH3CN, reflux, 1 h; f) KBH4, CH3OH, rt, 1 h;
g) PhB(OH)2, [Pd
ACHTUNGTRENNUNG
h) Ethynyl benzene, [PdCl CTHGNUTRENNUNG
i) Methyl acrylate, Pd
dimethylformamide.
ACHTUNGTRENNUNG
Acknowledgements
We are grateful to the Natural Science Foundation of China (20972042,
21172057), RFDP (20114104110005), ISTTCPHNP (104100510019),
PCSIRT (IRT 1061), and 2012IRTSTHN006 for financial support.
as a useful handle for various coupling reactions to give bi-
phenyl, diphenyl acetylene, or cinnamate in high efficiency.
Moreover, both iodo and carbonyl groups could be elaborat-
ed to give 1,3,5-trifunctionalized benzenes.[16]
Keywords: allenes · domino reactions · iodoaryl ketones ·
iodobenzaldehydes · synthetic methods
In summary, we have developed an efficient protocol for
the preparation of iodobenzaldehydes and iodoaryl ketones
through an iodine-promoted domino reaction of hepta-1,2-
dien-6-yn-4-ols through the cyclization of the in situ formed
enyne–allene intermediate. Compared with previous reports
on the cyclization of enyne–allene, the present method not
only provides a facile way to obtain the required enyne–
allene intermediate, but also reveals an unprecedented con-
current introduction of both iodo and carbonyl groups onto
the benzene ring as well as construction of the benzenoid
core. In a further aspect, we also discovered an easy-to-per-
form synthetic pathway towards diversely substituted ben-
zenes through a Brønsted acid promoted cascade reaction of
hepta-1,2,6-trien-4-ols that featured a cyclization of the in
situ formed diene–allene intermediate. With advantages
such as readily available starting materials, mild reaction
conditions, and diverse substitution pattern of products, the
synthetic processes developed in this study are expected to
be used as valuable alternative protocols for the preparation
of functionalized benzenes.
[1] a) X. Y. Guo, C. J. Li, Org. Lett. 2011, 13, 4977–4979; b) Y. Y. Liu,
J. P. Wan, Org. Biomol. Chem. 2011, 9, 6873–6894; c) R. Chinchilla,
C. Nꢂjera, Chem. Soc. Rev. 2011, 40, 5084–5121; d) C. L. Sun, Y. F.
Gu, W. P. Huang, Z. J. Shi, Chem. Commun. 2011, 47, 9813–9815;
e) M. Omote, M. Tanaka, A. Ikeda, S. Nomura, A. Tarui, K. Sato,
A. Ando, Org. Lett. 2012, 14, 2286–2289.
[2] a) C. Y. Wu, Y. C. Lin, P. T. Chou, Y. Wang, Y. H. Liu, Dalton Trans.
2011, 40, 3748–3753; b) P. Garcꢃa-Garcꢃa, A. Martꢃnez, A. M.
Sanjuꢂn, M. A. Fernꢂndez-Rodrꢃguez, R. Sanz, Org. Lett. 2011, 13,
4970–4973; c) H. W. Zhou, Y. P. Xing, J. Z. Yao, J. H. Chen, Org.
Lett. 2010, 12, 3674–3677; d) V. E. Ziffle, P. Cheng, D. L. J. Clive, J.
Org. Chem. 2010, 75, 8024–8038; e) Y. X. Shen, H. F. Jiang, Z. W.
Chen, J. Org. Chem. 2010, 75, 1321–1324.
[3] a) A. G. Myers, E. Y. Kuo, N. S. Finney, J. Am. Chem. Soc. 1989,
111, 8057–8059; b) A. G. Myers, P. S. Dragovich, E. Y. Kuo, J. Am.
Chem. Soc. 1992, 114, 9369–9386; c) R. Nagata, H. Yamanaka, E.
Okazaki, I. Saito, Tetrahedron Lett. 1989, 30, 4995–4998; d) R.
Nagata, Y. Hidenori, E. Murahashi, I. Saito, Tetrahedron Lett. 1990,
31, 2907–2910; e) A. G. Myers, P. S. Dragovich, J. Am. Chem. Soc.
1989, 111, 9130–9132.
[4] a) S. M. Ma, Chem. Rev. 2005, 105, 2829–2871; b) S. Sakai, M. Nishi-
tani, J. Phys. Chem. A 2010, 114, 11807–11813; c) K. Gilmore, I. V.
Alabugin, Chem. Rev. 2011, 111, 6513–6556; d) M. Schmittel, A. A.
Mahajan, G. Bucher, J. Am. Chem. Soc. 2005, 127, 5324–5325; e) J.
Zhao, C. O. Hughes, F. D. Toste, J. Am. Chem. Soc. 2006, 128, 7436–
7437.
[5] a) X. S. Fan, Y. Y. Wang, Y. Y. Qu, H. Y. Xu, Y. He, X. Y. Zhang,
J. J. Wang, J. Org. Chem. 2011, 76, 982–985; b) X. Y. Zhang, X. F.
Jia, L. L. Fang, N. Liu, J. J. Wang, X. S. Fan, Org. Lett. 2011, 13,
5024–5027; c) H. Y. Xu, X. Y. Zhang, Y. He, S. H. Guo, X. S. Fan,
Chem. Commun. 2012, 48, 3121–3123.
Experimental Section
Typical procedure for the preparation of 5-iodobiphenyl-3-carbaldehyde
(3a)
I2 (1 mmol) was added to a flask containing 4-phenylhepta-1,2-dien-6-yn-
4-ol (2a, 1 mmol) in CH3CN (5 mL). The solution was stirred under
reflux. Upon completion, the mixture was concentrated under vacuum.
The residue was purified by column chromatography on silica gel using
Chem. Asian J. 2013, 8, 717 – 722
721
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Xin-Ying Zhang, Xue-Sen Fan et al.
[6] For a recent preparation and reaction of hydroxylated 1,5-allenynes,
see: J. Ma, L. L. Peng, X. Zhang, Z. Zhang, M. Campbell, J. B.
Wang, Chem. Asian J. 2010, 5, 2214–2220.
[7] a) L. P. Feng, D. Kumar, D. M. Birney, S. M. Kerwin, Org. Lett.
2004, 6, 2059–2062; b) H. Hibbert, J. Am. Chem. Soc. 1915, 37,
1748–1763; c) G. Stavber, M. Zupan, S. Stavber, Tetrahedron Lett.
2006, 47, 8463–8466.
[8] The molecular structure of 3 f was determined by X-ray crystallo-
graphic analysis. CCDC 884851 contains the supplementary crystal-
lographic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.
[11] P. Neuhaus, Synthesis and Characterization of Organic High-Spin
Molecules, doctoral dissertation, 2012, Ruhr-Universitꢄt Bochum.
[12] a) J. N. Moorthy, N. Singhal, K. Senapati, Tetrahedron Lett. 2006, 47,
1757–1761; b) S. Das, A. K. Panigrahi, G. C. Maikap, Tetrahedron
Lett. 2003, 44, 1375–1377; c) S. W. Kshirsagar, N. R. Patil, S. D.
Samant, Tetrahedron Lett. 2008, 49, 1160–1162.
[13] The molecular structure of 3’-iodo-5’-(iodomethyl)biphenyl-4-car-
bonitrile (V) was determined by X-ray crystallographic analysis.
CCDC 884853 contains the supplementary crystallographic data for
this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
[9] For I2-promoted formation of carbocation from tertiary alcohol, see:
J. Choi, G. H. Lee, I. Kim, Synlett 2008, 1243–1249.
[14] a) I. Nakamura, D. Zhang, M. Terada, J. Am. Chem. Soc. 2010, 132,
7884–7886; b) E. M. Cabaleiro-Lago, J. Rodriguez-Otero, R. M.
Garcia-Lꢅpez, A. Pena-Gallego, J. M. Hermida-Ramon, Chem. Eur.
J. 2005, 11, 5966–5974; c) C. S. Lꢅpez, O. N. Faza, F. P. Cossio, D. M.
York, A. R. de Lera, Chem. Eur. J. 2005, 11, 1734–1738.
[15] H. Zhou, Y. Xing, J. Yao, Y. Lu, J. Org. Chem. 2011, 76, 4582–4590.
[16] a) B. Liu, R. S. Shetty, K. K. Moffett, M. J. Kelly, Tetrahedron Lett.
2011, 52, 1680–1684; b) J. Georgsson, C. Skçld, B. Plouffe, G. Linde-
berg, M. Botros, M. Larhed, F. Nyberg, N. Gallo-Payet, A. Gogoll,
A. Karlꢆn, A. Hallberg, J. Med. Chem. 2005, 48, 6620–6631.
[10] For I2-promoted cyclizations, see: a) L.-J. Wang, H.-T. Zhu, L. Lu, F.
Yang, X.-Y. Liu, Y.-M. Liang, Org. Lett. 2012, 14, 1990–1993; b) F.
Yang, K.-G. Ji, H.-T. Zhu, A. Shaukat, X.-Y. Liu, Y.-M. Liang,
Chem. Eur. J. 2011, 17, 4986–4990; c) H.-T. Zhu, K.-G. Ji, F. Yang,
L.-J. Wang, S.-C. Zhao, S. Ali, X.-Y. Liu, Y.-M. Liang, Org. Lett.
2011, 13, 684–687; d) B. Godoi, R. F. Schumacher, G. Zeni, Chem.
Rev. 2011, 111, 2937–2980; e) B. Crone, S. F. Kirsch, K.-D. Umland,
Angew. Chem. 2010, 122, 4765–4768; Angew. Chem. Int. Ed. 2010,
49, 4661–4664; f) A. Palisse, S. F. Kirsch, Org. Biomol. Chem. 2012,
10, 8041–8047; g) A. Sakakura, A. Ukai, K. Ishihara, Nature 2007,
445, 900–903; h) A. Sakakura, G. Shomi, A. Ukai, K. Ishihara, Het-
erocycles 2010, 82, 249–255; i) A. Sakakura, K. Ishihara, Chim. Oggi
2007, 25, 9–12.
Received: December 3, 2012
Revised: December 16, 2012
Published online: January 21, 2013
Chem. Asian J. 2013, 8, 717 – 722
722
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim