Synthesis of 1-naphthaldehydes via the cascade reactions of 1-phenylpent-4-yn-2-ols promoted by iodine monochloride

Article abstract of DOI:10.1016/j.tetlet.2016.03.047

A novel and convenient synthesis of 1-naphthaldehydes through iodine monochloride promoted cascade reactions of 1-phenylpent-4-yn-2-ols is presented. Compared with literature procedures, this new method has advantages such as simple operation procedure, mild reaction conditions, good efficiency, and excellent regio-selectivity.

Full text of DOI:10.1016/j.tetlet.2016.03.047

Tetrahedron Letters 57 (2016) 1843–1846
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Tetrahedron Letters
journal homepage: www.elsevier.com/locate/tetlet
Synthesis of 1-naphthaldehydes via the cascade reactions of
1-phenylpent-4-yn-2-ols promoted by iodine monochloride
⇑
Bin Li, Nana Shen, Xuesen Fan , Xinying Zhang
School of Environment, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key
Laboratory of Green Chemical Media and Reactions, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan
Normal University, Xinxiang, Henan 453007, China
a r t i c l e i n f o
a b s t r a c t
Article history:
A novel and convenient synthesis of 1-naphthaldehydes through iodine monochloride promoted cascade
reactions of 1-phenylpent-4-yn-2-ols is presented. Compared with literature procedures, this new
method has advantages such as simple operation procedure, mild reaction conditions, good efficiency,
and excellent regio-selectivity.
Received 5 January 2016
Revised 12 March 2016
Accepted 15 March 2016
Available online 15 March 2016
Ó 2016 Elsevier Ltd. All rights reserved.
Keywords:
1
-Naphthaldehydes
Iodine monochloride
Cascade reaction
Introduction
1-naphthyl iodide. Cyanation with an excess amount of copper(I)
cyanide followed by reduction with DIBAL afforded 7-methoxy-1-
Aldehydes are undoubtedly one of the most important classes
of organic compounds as their diverse reactivity has made them
indispensable as synthetic intermediates in the preparation of a
naphthaldehyde. As the second strategy, 1-naphthaldehydes were
prepared via the annulation reactions of functionalized benzenes.
In this regard, Shi reported a convenient method to synthesize 2-
chloro-3-(2-chloroethyl)-1-naphthaldehydes via the Vilsmeier–
Haack reaction of 1-cyclopropyl-2-arylethan- ones (Scheme 1, 4).6
More recently, Iwasawa reported a concise method for the prepa-
ration of 4-alkoxy or 4-alkyl sulfanyl-1-naphthaldehydes by react-
1
myriad of functional organic molecules. Among them, 1-naph-
thaldehyde and its derivatives have found wide applications in
the synthesis of different kinds of pharmaceuticals and fine
2
chemicals. Due to their importance, a number of methods to
prepare 1-naphthaldehydes have been developed. One of the most
frequently used strategies involves the regio-selective introduction
of the formyl group onto the existing naphthalene scaffold or via
the transformation of other functional groups into the aldehyde.
ing o-ethynylbenzoates or benzothioates with vinyl ethers in the
7
presence of PtCl
2
(Scheme 1, 5). In addition, 1-naphthaldehydes
have also been prepared through the intramolecular alkylation
and cyclization of (E)-2-(arylmethylene)cyclopropylaldehyde
8
As an example,
a
-naphthaldehyde was synthesized by treating
mediated by organo-selenium reagents (Scheme 1, 6). While these
a
-chloromethylnaphthalene with hexamethylenetetramine, and
literature protocols are generally efficient and reliable, some of
them more or less still suffer from tedious operation procedures,
harsh reaction conditions, and toxic or expensive reagents.
Therefore, to develop new synthetic methods to prepare 1-naph-
thaldehydes from readily available starting materials and under
mild conditions remains an attractive but still challenging task.
As a continuation of our recent interests in exploring the versa-
tile reaction patterns of allenic alcohols and homo-propargyl alco-
the required a-chloromethylnaphthalene was obtained by reacting
naphthalene with formaldehyde and hydrochloric acid followed by
treatment with concentrated sulfuric acid (Scheme 1, 1). In
another example, Boswell, et al reported that 4-fluoro-1-naph-
thaldehyde could be obtained with good yields by formylation of
3
1
-fluoronaphthalene with dichloro methyl methyl ether and tin
4
(
IV) chloride (Scheme 1, 2). The third example involves the prepa-
9
ration of 7-methoxy-1-naphthaldehyde from the corresponding
amine (Scheme 1, 3).5 Thus, diazotization of 7-methoxynaph-
thalen-1-amine followed by treatment with potassium iodide gave
hols, and inspired by the diverse reactivity of iodine monochloride
10
(ICl) demonstrated in various transformations, we have studied
the reaction of 1-phenylpent-4-yn-2-ols in the presence of ICl.
From this reaction, a convenient and efficient synthetic approach
toward 1-naphthaldehydes was successfully developed. Herein,
we report our results in this aspect.
⇑
Corresponding author. Tel.: +86 373 3329261; fax: +86 373 3329275.
E-mail address: xuesen.fan@htu.cn (X. Fan).
http://dx.doi.org/10.1016/j.tetlet.2016.03.047
040-4039/Ó 2016 Elsevier Ltd. All rights reserved.
0

1
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B. Li et al. / Tetrahedron Letters 57 (2016) 1843–1846
CHO
F
8–9). In the following studies, the reaction of 1a was tried at tem-
peratures lower or higher than room temperature (entries 10–11).
However, no improvement in the yield of 2a was observed. Finally,
3 3 2
FeCl , BBr , and I were also tried as possible reagents to replace ICl
to promote this transformation (entries 12–14). Unfortunately, no
desired product was obtained from these reactions.
1
) HCHO/HCl, H SO4
2
1
)
2
) N (CH )
4
2 6
F
Cl CHOCH , SnCl
2
3
4
2)
With the optimized reaction conditions in hand, the scope and
generality of this novel synthesis of 1-naphthaldehydes was stud-
ied. Thus, several 1-phenylpent-4-yn-2-ol substrates (1) with dif-
ferent substituents on the phenyl ring were prepared and treated
CH Cl
2
2
CHO
NH
2
CHO
H CO
H CO
3
(i) NaNO /HCl; (ii) KI
3
11
2
with ICl. The results listed in Table 2 showed that while the R
3)
(iii) CuCN; (IV) DIBAL
CHO
Table 2
Cl
POCl /DMF
a
3
Substrate scope for the synthesis of 2
4)
O
120-135 o
C
Cl
CHO
OR1
O
OR1
OH
ICl
CH Cl , air, rt, 0.5 h
R
R
2
2
cat. PtCl2
5)
+
OR
1
2
Toluene, rt
CHO
Yieldb (%)
Entry
1
Substrates
Products
CHO
CHO
Ph
OH
1a
N-PSP, (NH ) S O
4
2
2
8
6)
DMSO, 70 o
64
73
71
68
O
C
PhSe
H
2
a
Scheme 1. Literature methods for the preparation of 1-naphthaldehydes.
H
3
CO
CO
CHO
CHO
OH
OH
H CO
3
2
3
4
H
3
Initially, 1-phenylpent-4-yn-2-ol (1a) was treated with 1 equiv
at ambient temperature for 0.5 h. From this reac-
tion, to our delight, 1-naphthaldehyde (2a) was obtained in a yield
H
3
CO
1
b
of ICl in CH
2
Cl
2
2b
3
H CO
of 38% (Table 1, entry 1). To improve the efficiency, different sol-
H
CO
3
vents including CH
3
CN, CH
3
OH, DMF and THF were then tried.
Cl
1
c
However, they were found to be much less effective than CH
2
2
2
c
in mediating this reaction (entries 2–5). When the amount of ICl
was reduced to 0.5 equiv, the yield of 2a decreased obviously
entry 6). On the other hand, the yield of 2a could be increased
to 64% when 2 equiv of ICl were used (entry 7). Further an increase
H
3
C
CHO
OH
H C
3
(
1
d
in the amount of ICl did not result in higher yields of 2a (entries
2
d
CHO
OH
Table 1
3
H C
Optimization study on the synthesis of 2a from 1aa
5
71
1
e
H C
3
CHO
2
e
OH
conditions
CHO
OH
1
a
2
a
6
7
CH
3
65
55
1
f
Yieldb (%)
CH
3
Entry
Promoter (equiv)
Solvent
T (°C)
2
f
1
2
3
4
5
6
7
8
9
ICl (1)
ICl (1)
ICl (1)
ICl (1)
ICl (1)
ICl (0.5)
ICl (2)
ICl (3)
ICl (4)
ICl (2)
ICl (2)
CH
2
CH
3
CH
3
Cl
CN
OH
2
rt
rt
rt
rt
rt
rt
rt
rt
rt
0
38
8
—
—
7
27
64
65
60
23
62
—
F
CHO
OH
F
DMF
THF
1g
CH
2
CH
2
CH
2
CH
2
CH
2
CH
2
CH
2
CH
2
CH
2
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
2
2
2
2
2
2
2
2
2
2
g
CHO
OH
1
1
1
1
1
0
1
2
3
4
40
rt
rt
rt
8
67
FeCl
BBr
(2)
3
(2)
(2)
1h
3
—
—
I
2
2h
2 2
(2 mL), ICl (1 mL, 1 M in CH Cl ), air,
a
a
Reaction conditions: 0.5 mmol of 1a, solvent (2 mL), ICl (1 M in CH
.5 h.
2
Cl
2
), air,
Reaction conditions: 0.5 mmol of 1, CH
rt, 0.5 h.
2
Cl
2
0
b
b
Isolated yield.
Isolated yield.

B. Li et al. / Tetrahedron Letters 57 (2016) 1843–1846
1845
unit in 1 could be either the electron-donating methyl, methoxyl,
dimethoxyl (entries 2–6), or the electron-withdrawing fluoro
group (entry 7), substrates with EDGs are more efficient than that
with EWG. Interestingly, this method showed excellent regio-
selectivity as shown by the reaction of 1b and 1e, from which only
one of the two possible regio-isomers was obtained. It is also worth
to be noted that 1-naphthylpent-4-yn-2-ol (1h) was found to be a
suitable substrate to undergo this cascade reaction to give phenan-
threne-1-carbaldehyde (2h) in 67% yield.
in Scheme 3, Eq. 1 might be explained that under a nitrogen atmo-
sphere, VI could not be transformed into 2a. Under this circum-
stance, it underwent a nucleophilic substitution reaction with
chloride ion to give VII.
In conclusion, we have developed a simple and convenient syn-
thesis of 1-naphthaldehydes through iodine monochloride pro-
moted cascade reaction of 1-phenylpent-4-yn-2-ols. By using this
method, a group of diversely substituted 1-naphthaldehydes were
successfully obtained. Compared with previous methods, the pro-
tocol reported herein has the advantages such as simple synthetic
procedure, mild reaction conditions, good yield, and excellent
regio-selectivity.
Based on the above observations and related literature, a plau-
sible pathway accounting for the formation of 2a from the reaction
of 1a is proposed in Scheme 2. Initially, coordination of ICl to the
carbon–carbon triple bond in 1a affords an iodonium intermediate
I, which then undergoes an intramolecular Friedel–Crafts type
reaction to give intermediate II. The following dehydration, tau-
tomerization and aromatization afford intermediates III, IV, V
and VI. Finally, oxidation of VI under the reaction conditions
affords 2a as the final product.1
Acknowledgments
This work was financially supported by the National Natural
Science Foundation of China (NSFC) (grant numbers 21272058,
21572047), Program for Innovative Research Team in Science and
Technology in Universities of Henan Province (15IRTSTHN003),
Program for Science and Technology Innovation Talents in
Universities of Henan Province (15HASTIT005).
2,9f
The plausible reaction mechanism proposed in Scheme 2 is
partly supported by the following control experiments. Firstly,
treating 1a with ICl under a nitrogen atmosphere afforded a mix-
ture of 4-(iodomethylene)-1,2,3,4-tetrahydronaphthalen-2-ol (II),
1
-(iodomethyl)naphthalene (VI), as well as 1-(chloromethyl)naph-
References and notes
thalene (VII, Scheme 3, Eq. 1). Next, treatment of II under standard
conditions affords 2a (Scheme 3, Eq. 2). Finally, it was observed
that upon treatment of the mixture of VI and VII under standard
conditions, VI was consumed to afford 2a while VII remained
intact (Scheme 3, Eq. 3). By the way, the formation of VII as shown
1
.
(a) Reddy, L. V. R.; Kumar, V.; Sagar, R.; Shaw, A. K. Chem. Rev. 2013, 113, 3605;
b) Szostak, M.; Fazakerley, N. J.; Parmar, D.; Procter, D. J. Chem. Rev. 2014, 114,
959; (c) Rotstein, B. H.; Zaretsky, S.; Rai, V.; Yudin, A. K. Chem. Rev. 2014, 114,
(
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(a) Supsana, P.; Tsoungas, P. G.; Varvounis, G. Tetrahedron Lett. 2000, 41, 1845;
(
b) Chang, J. H.; Shin, H. Org. Process Res. Dev. 2008, 12, 291; (c) Reddy, B. V. S.;
Reddy, P. S.; Reddy, Y. J.; Yadav, J. S. Tetrahedron Lett. 2011, 52, 5789;
d) Sundar, C. S.; Reddy, M. R.; Sridhar, B.; Kumar, S. K.; Reddy, C. S.; Reddy, B. V.
(
S. Tetrahedron Lett. 2014, 55, 4236.
Coles, H. W.; Dodds, L. M. J. Am. Chem. Soc. 1938, 60, 853.
I
3.
OH
OH
4. Boswell, G. E.; Licause, J. F. J. Org. Chem. 1995, 60, 6592.
ICl
Cl
5
.
Kandagatla, B.; Raju, V. V. N. K. V. P.; Reddy, G. M.; Rao, S. C.; Iqbal, J.;
Bandichhor, R.; Oruganti, S. Tetrahedron Lett. 2012, 53, 7125.
Tang, X.; Shi, M. J. Org. Chem. 2008, 73, 8317.
H
I
1
a
I
OH
6.
.
II
7
Kusama, H.; Funami, H.; Takaya, J.; Iwasawa, N. Org. Lett. 2004, 6, 605.
I
I
I
8. Miao, M.; Huang, X. J. Org. Chem. 2009, 74, 5636.
9.
(a) Fan, X.; Wang, Y.; Qu, Y.; Xu, H.; He, Y.; Zhang, X.; Wang, J. J. Org. Chem.
2011, 76, 982; (b) He, Y.; Zhang, X.; Shen, N.; Fan, X. J. Org. Chem. 2013, 78,
H
10178; (c) He, Y.; Zhang, X.; Fan, X. Chem. Commun. 2015, 16263; (d) Xu, H.;
OH
2
H O
H
Zhang, X.; He, Y.; Guo, S.; Fan, X. Chem. Commun. 2012, 3121; (e) Cui, L.; Wang,
X.; He, Y.; Fan, X. J. Chin. Chem. Soc. 2014, 61, 233; (f) He, Y.; Zhang, X.; Cui, L.;
Fan, X. Chem. Asian J. 2013, 8, 717.
2
III
IV
CHO
V
I
10. (a) Ercegovic, T.; Meijer, A.; Magnusson, G.; Ellervik, U. Org. Lett. 2001, 3, 913;
b) Heasley, V. L.; Buczala, D. M.; Chappell, A. E.; Hill, D. J.; Whisenand, J. M.;
(
O
Shellhamer, D. F. J. Org. Chem. 2002, 67, 2183; (c) Bellina, F.; Colzi, F.; Mannina,
L.; Rossi, R.; Viel, S. J. Org. Chem. 2003, 68, 10175; (d) Wariishi, K.; Morishima,
S.; Inagaki, Y. Org. Process Res. Dev. 2003, 7, 98; (e) Suryakiran, N.; Reddy, T. S.;
Suresh, V.; Lakshman, M.; Venkateswarlu, Y. Tetrahedron Lett. 2006, 47, 4319.
1. Typical procedure for the preparation of 1-naphthaldehyde (2a). To a flask
containing a solution of 1-phenylpent-4-yn-2-ol (1a, 80 mg, 0.5 mmol) in dry
VI
2a
1
Scheme 2. Plausible pathway accounting for the formation of 2a from 1a.
I
I
Cl
ICl (2 eq)
1
)
CH Cl , r.t., N2
OH
2
2
OH
1a
II
VI
VII
I
CHO
standard conditions
standard conditions
2
)
OH
II
2a
I
Cl
Cl
CHO
3
)
2
a
VI
VII
VII
Scheme 3. Control experiments.

1
846
B. Li et al. / Tetrahedron Letters 57 (2016) 1843–1846
CH
the mixture was stirred at room temperature under an air atmosphere for
.5 h. The reaction was quenched with aqueous Na solution and extracted
with CH Cl
(5 mL Â 3). The combined organic layers were washed with brine,
and then dried over anhydrous Na SO . The solvent was evaporated under
2
Cl
2
(2 mL) was added ICl (1 mL, 1 M in CH
2
Cl
2
) in a dropwise manner. Then,
7.59 (t, J = 7.6 Hz, 1H), 7.69 (s, 1H), 7.92 (d, J = 6.8 Hz, 1H), 8.01 (d, J = 8.0 Hz,
1H), 9.14 (d, J = 8.8 Hz, 1H), 10.38 (s, 1H); 13C NMR (100 MHz, CDCl
) d: 21.6,
124.7, 124.9, 127.5, 128.7, 131.3, 131.4, 134.1, 134.7, 135.8, 136.8, 193.6; MS:
3
0
2 2 3
S O
+
15 1
2
2
3
m/z 171 (MH) . 5-Methyl-1-naphthaldehyde (2f) : H NMR (400 MHz, CDCl )
2
4
d: 2.72 (s, 3H), 7.41 (d, J = 6.8 Hz, 1H), 7.55–7.59 (m, 1H), 7.60–7.64 (m, 1H),
7.95–7.97 (m, 1H), 8.26 (d, J = 8.4 Hz, 1H), 9.12 (d, J = 8.4 Hz, 1H), 10.40 (s, 1H);
vacuum and the crude product was purified by column chromatography on
silica gel using petroleum ether–ethyl acetate (10:1) as eluent to give
1
3
C NMR (100 MHz, CDCl
3
) d: 19.9, 122.9, 124.7, 127.8, 128.8, 130.9, 131.2,
+
1
-naphthaldehyde (2a, 50 mg, 64%). Substituted 1-naphthaldehydes (2b–2h)
131.7, 132.9, 134.8, 136.0, 193.6; MS: m/z 171 (MH) . 7-Fluoro-1-naphthalde-
hyde (2g)16
7.60 (t, J = 7.6 Hz, 1H), 7.90–7.93 (m, 1H), 8.01 (d, J = 6.8 Hz, 1H), 8.09 (d,
J = 8.4 Hz, 1H), 8.99 (dd, J = 8.0 Hz, J
= 2.4 Hz,, 1H), 10.32 (s, 1H); 13C NMR
(100 MHz, CDCl ) d: 109.4 (d, JC–F = 22.9 Hz), 117.4 (d, JC–F = 25.6 Hz), 124.2,
:
1
were obtained in a similar manner. Details of analytical data of products 2a–2h
3 1 2
H NMR (400 MHz, CDCl ) d: 7.37 (dt, J = 8.0 Hz, J = 2.4 Hz, 1H),
3
1
are presented as follows: 1-Naphthaldehyde (2a) : H NMR (400 MHz, CDCl
d: 7.58–7.64 (m, 2H), 7.67–7.72 (m, 1H), 7.92 (d, J = 7.6 Hz, 1H), 7.98–7.99 (m,
H), 8.10 (d, J = 8.0 Hz, 1H), 9.26 (d, J = 8.0 Hz, 1H), 10.40 (s, 1H); 13C NMR
100 MHz, CDCl ) d: 124.9, 127.0, 128.5, 129.1, 130.6, 131.4, 133.7, 135.3,
3
)
1
2
1
(
3
3
130.8 (d, JC–F = 9.6 Hz), 131.0 (d, JC–F = 6.8 Hz), 131.4, 131.5, 135.1, 138.0, 163.1
+
13
1
+
1
36.7, 193.6; MS: m/z 157 (MH) . 6,7-Dimethoxy-1-naphthaldehyde (2b)
) d: 4.01 (s, 3H), 4.07 (s, 3H), 7.17 (s, 1H), 7.48 (t,
J = 7.2 Hz, 1H), 7.80–7.82 (m, 1H), 7.93 (d, J = 8.0 Hz, 1H), 8.78 (s, 1H), 10.26 (s,
:
H
(d, JC–F = 247.2 Hz), 193.3; MS: m/z 175 (MH) . Phenanthrene-1-carbaldehyde
(2h)17
:
1
NMR (400 MHz, CDCl
3
3
H NMR (400 MHz, CDCl ) d: 7.64–7.72 (m, 2H), 7.74–7.78 (m, 1H),
7.91–7.95 (m, 2H), 8.04–8.06 (m, 1H), 8.66 (d, J = 8.8 Hz, 1H), 8.93 (d, J = 8.4 Hz,
H); 13C NMR (100 MHz, CDCl
30.0, 133.5, 136.0, 149.8, 152.2, 194.3; MS: m/z 217 (MH) . 7-Methoxy-1-
) d: 55.8, 56.1, 104.2, 106.6, 123.2, 126.7, 129.9,
13
1
1
3
3
1H), 9.13 (d, J = 9.2 Hz, 1H), 10.49 (s, 1H); C NMR (100 MHz, CDCl ) d: 122.2,
+
122.8, 125.7, 127.2, 127.3, 128.7, 129.0, 129.8, 130.2, 130.4, 130.9, 131.6, 131.8,
5
1
+
naphthaldehyde (2c) : H NMR (400 MHz, CDCl
= 8.8 Hz, = 2.4 Hz, 1H), 7.48 (dd, = 8.4 Hz,
J = 9.2 Hz, 1H), 7.94 (dd, J = 7.2 Hz, J = 1.2 Hz, 1H), 8.02 (d, J = 7.6 Hz, 1H),
3
) d: 3.40 (s, 3H), 7.25 (dd,
J
135.2, 193.6; MS: m/z 207 (MH) .
J
1
J
2
J
1
1
= 2.8 Hz, 1H), 7.81 (d,
12. (a) Moorthy, J. N.; Singhal, N.; Senapati, K. Tetrahedron Lett. 2006, 47, 1757; (b)
Das, S.; Panigrahi, A. K.; Maikap, G. C. Tetrahedron Lett. 2003, 44, 1375; (c)
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13. Pansare, S. V.; Ravi, R. G. Synlett 1994, 823.
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15. Sydnes, L. K.; Burkow, I. C.; Hansen, S. H. Tetrahedron 1985, 41, 5703.
16. Schnur, R. C. U.S. 1983, U.S. 4367234 A 19830104.
17. Pampín, M. C.; Estévez, J. C.; Estévez, R. J.; Maestrob, M.; Castedo, L. Tetrahedron
2003, 59, 7231.
1
2
3
1
8
.76 (d, J = 2.4 Hz, 1H), 10.32 (s, 1H); C NMR (100 MHz, CDCl
3
) d: 55.5, 103.6,
1
19.8, 122.5, 129.3, 129.9, 132.2, 135.1, 138.2, 160.7, 194.0; MS: m/z 187
+
14 1
(
MH) . 7-Methyl-1-naphthaldehyde (2d)
s, 3H), 7.43 (d, J = 8.0 Hz, 1H), 7.55 (t, J = 8.0 Hz, 1H), 7.81 (d, J = 8.4 Hz, 1H),
.95 (d, J = 6.4 Hz, 1H), 8.04 (d, J = 8.8 Hz, 1H), 9.07 (s, 1H), 10.37 (s, 1H); 13
:
H NMR (400 MHz, CDCl
3
) d: 2.59
(
7
C
NMR (100 MHz, CDCl
3
) d: 22.3, 123.96, 123.98, 128.3, 129.1, 130.82, 130.85,
+
1
32.0, 135.1, 137.0, 139.4, 193.7; MS: m/z 171 (MH) . 6-Methyl-1-naphthalde-
14 1
hyde (2e)
:
H NMR (400 MHz, CDCl
3
) d: 2.54 (s, 3H), 7.53 (d, J = 8.4 Hz, 1H),