'On-water' synthesis of chromeno-isoxazoles mediated by [hydroxy(tosyloxy)iodo]benzene (HTIB)

Article abstract of DOI:10.1039/b926085d

An efficient and handy method for the synthesis of chromeno-isoxazole/ isoxazolines under 'on-water' conditions is described, together with a thorough mechanistic study.

Full text of DOI:10.1039/b926085d

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www.rsc.org/greenchem | Green Chemistry
‘On-water’ synthesis of chromeno-isoxazoles mediated by
[hydroxy(tosyloxy)iodo]benzene (HTIB)†
Mustafa J. Raihan, Veerababurao Kavala, Chun-Wei Kuo, B. Rama Raju and Ching-Fa Yao*
Received 10th December 2009, Accepted 25th March 2010
First published as an Advance Article on the web 12th May 2010
DOI: 10.1039/b926085d
An efficient and handy method for the synthesis of chromeno-isoxazole/isoxazolines under
‘on-water’ conditions is described, together with a thorough mechanistic study.
used as synthetic precursors in the construction of various
pharmaceutically useful compounds.4
Introduction
Isoxazoles and isoxazolines, two major classes of five-membered
nitrogen heterocycles, are ubiquitous structural motifs that
are found in a wide spectrum of organic molecules, some of
which are biomedically important.1 They have been used as
building blocks in the synthesis of numerous natural products,
and the procedures have been extensively documented in the
literature. Their utility stems from their intrinsic properties,
i.e., selective ring opening to produce g-amino alcohols, b-
hydroxy ketones, b-hydroxy nitriles, b-hydroxy acids and esters
and a,b- and b,g-unsaturated ketones.2 In particular, certain
fused tricyclic derivatives comprised of isoxazoline/isoxazole
and benzopyaran/naphthopyran units are known to possess
multidrug functions (Fig. 1) with antidepressant, antipsychotic
and antianxiolytic activities.3 Apart from these, they are also
The in situ formation of a nitrile oxide and its intramolecular
dipolar cycloaddition is one of the most extensively employed
tools for the preparation of isoxazoline/isoxazole derivatives.5
In this regard, like many other research groups around the
world,6 we have developed some synthetic routes to isoxazoles
via the dehydration of nitroalkanes in the last few decades.7
It is also noteworthy that a brief literature survey reveals that
the dehydrohalogenation of hydroximoyl chlorides8 and the
oxidation of aldoximes9 are also commonly used procedures
for the generation of dipoles. In the synthesis of tricyclic
isoxazoles, for example, the most frequently used reagent for
oxidizing an aldoxime is NaOCl.3,10 However, product yields
using NaOCl reported by different groups are highly variable.3,10
MagtrieveTM, CAN, KI/I2, DIB, PhIO/CTAB, PhICl2, NCBT
and chloramine-T are also oxidizing agents that can be used for
the same purpose.11,10b Concerning the use of aqueous media,
to our knowledge, only Hailes et al.10d (using NaOCl) and
Maiti et al.11d (using PhIO/CTAB) have reported attempts to
accomplish these goals. A limitation of the former method is that
it requires a long time to complete a reaction and is applicable
only to a limited number of examples. In the latter case, the
reaction does not proceed in the absence of a cationic surfactant.
In addition, these methods all involve the use of either toxic
solvents, a complex combination of reagents or require a long
reaction time. These facts prompted us to search for a better
alternative.
In this context, from the viewpoint of cost, safety and
environmental concerns, water is the most convenient solvent
for synthetic purposes.12 A plethora of chemical reactions in
which water is used as the solvent have been described in
the literature, even in cases where the substrate is insoluble
in water. In particular, during the past few years, reactions of
water-insoluble organic compounds that take place in aqueous
suspensions (‘on water’) have received a great deal of attention
because of their high efficiency and the straightforward synthetic
protocols involved.13 The advantages of conducting organic
reactions ‘on water’ can be attributed to an enhancement in
efficiency and rate, operational convenience and an improved
safety profile owing to the excellent heat capacity of water.14
In a continuation of our ongoing project on the develop-
ment of green synthetic protocols based on the ‘on-water’
concept,15 we herein report our attempts to synthesize
Fig. 1 Bioactive and synthetically important tricyclic isoxazoline
molecules.
Department of Chemistry, National Taiwan Normal University, 88, Sec.
4, Tingchow Road, Taipei, Taiwan, 116, R. O. C.
E-mail: cheyaocf@ntnu.edu.tw; Fax: +886-2-29324249;
Tel: +886-2-29309092
† Electronic supplementary information (ESI) available: Experimental
information. CCDC reference numbers 751947, 751948, 751949 and
757190. For ESI and crystallographic data in CIF or other electronic
format see DOI: 10.1039/b926085d
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Table 1 Comparison of solventsa
Table 2 Comparison of reagents
Yield (%)a
Entry
Solvent
Yield (%)b
Entry
Reagent
Time (h)
1
2
3
4
5
6
7
MeOH
DMF
CH3CN
THF
H2O
CH2Cl2
Toluene
91
90
90
89
92
88
79
1
2
3
4b
5
6
CAN
Iodine
H2O2
PhIO/CTAB
DIB
HTIB
3
27
—
—
77
50
79
24
24
3
0.75
0.75
a Isolated yields. b Ref. 11d.
a Using 1.1 equiv. HTIB. b NMR yield, using CH2Br2 as internal
standard.
observed. With a 1.1 equiv. of HTIB, the yield of the expected
product reached a maximum, again with a minute amount
of deoximination being observed. No further improvement in
yields were observed with larger amounts of reagent. Hence we
used 1.1 equiv. of HTIB in subsequent investigations.
tricyclic isoxazole derivatives under ‘on-water’ conditions using
[hydroxy(tosyloxy)iodo]benzene (HTIB or Koser’s reagent) as
the oxidizing agent. The reason behind our choice of HTIB is
that it is easy to handle, remarkably stable (with a long shelf-
life) and has widespread synthetic applications that cover areas
such as tosyloxylation, azidation, and hydroxylation,16 the syn-
thesis of heterocyclic compounds,17 oxidative rearrangements
and fragmentation,18 and the oxidation of aldoximes, benzyl
alcohols, glucals, sulfides and alkyl ketones.19
With the optimized conditions in hand, a wide range of
substituted and unsubstituted 2-allyloxy/propargyloxy ben-
zaldoximes were converted to their corresponding tricyclic
isoxazoline derivatives in good to high yield. Evidence of the
scope of this methodology with respect to various substituted 2-
allyloxybenzaldoximes is shown in Table 3. The unsubstituted 2-
allyloxybenzaldoxime and the substrates with electron-donating
groups underwent smooth cyclisations to give tricyclic isoxazo-
lines in high yields. However, moderate yields were obtained in
case of chloro- and bromo-substituted 2-allyloxybenzaldoximes.
Moreover, when the substrate contained a strongly electron-
withdrawing group (NO2), the yield was only 56%. A further
interesting point to note is the extent of deoximination with
respect to substitution on the benzene ring. In the case of the
first four entries (entries 1–4), the amount of deoximination
product is less than 4%. It exceeded 4% in the case of the 5-
Cl derivative (entry 5) and reached 12% for the 5-Br deriva-
tive (entry 6). On introducing a further electron-withdrawing
group, such as a nitro group (entry 7) extent of deoximination
reached 30%.
Results and discussion
In our initial studies, we focused our attention on optimizing
the reaction conditions. Methanol was initially used as a
solvent because both the substrate and reagent are methanol-
soluble. In the first experiment, we used the simplest oxime,
2-(allyloxy)benzaldehyde oxime, and the product, 3a,4-dihydro-
3H-chromeno[4,3-c]isoxazole, was obtained in good (77%)
yield. In a search of a better protocol, we carried out the same
reaction using different solvents, and the yields were similar
in all cases, except when toluene was used (Table 1). Given
these circumstances, considering the advantages of using water
as a solvent and its positive impact in the area of synthetic
chemistry,12,13,14 we examined the use of water as a solvent, and
the results were found to be comparable to those using other
solvents.
After choosing a suitable solvent, we examined a number
of comparable or readily available oxidizing agents in aqueous
media, in an attempt to identify a better alternative to HTIB.
No product was found when iodine or H2O2 were used as
oxidants. On the other hand, the use of CAN resulted in
a yield of only 27% of the expected product. We then used
iodobenzenediacetate (DIB), but the product was obtained in
only 50% yield. The results are shown in Table 2. All these
results clearly point to the superiority of HTIB compared to
other oxidizing agents in aqueous media.
The scope of this methodology was further investigated using
branched 2-allyloxybenzaldoximes to better understand the
stereochemical aspects of our methodology (Table 4).
The reactions of branched 2-allyloxybenzaldoximes also
furnished moderate to excellent product yields. In particular,
the presence of an acetate group resulted in high yields. The
stereospecificity of the reactions was quite remarkable. Only
one product was stereospecifically produced in almost all cases.
NMR spectra showed the presence of a few extra peaks at higher
field, due to the presence of another isomer, only in case of 10a
and 11a. From the crystal structures of the products 14a, 16a and
17a (Fig. 2), it can be seen that the addition is stereospecifically
syn, which is consistent with a concerted [3+2] cycloaddition
reaction in the final step. Less than 4% deoximination product
was observed in all cases.
Once a suitable solvent and reagent was selected, our next
aim was to optimize the amount of reagent required for the
reaction. We first concentrated on determining its catalytic
efficiency. Using the same oxime and with a 10 mol% loading
of HTIB, only a trace amount of the product was formed. An
increase of the loading to 50 mol% resulted in a 35% yield of
the expected product, and a trace amount of deoximination was
After successfully accomplishing the intramolecular cyc-
lization of 2-allyloxy, branched 2-allyloxy and 2-cyclo-
hexenyloxybenzaldoximes, we focused our attention
on the synthesis of tricyclic isoxazole derivatives from
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Table 3 HTIB-mediated synthesis of tricyclic isoxazoline derivatives
Table 4 HTIB-mediated synthesis of tricyclic isoxazoline derivatives
under ‘on-water’ conditionsa
under ‘on-water’ conditionsa
Entry
1
Aldoxime
Product
Yield (%)b
79
Entry Aldoxime
1
Product
Yield (%)b
85
2
70
2
3
4
85
85
86
3
4
86
66
5
6
7
65
88
89
5
6
7
8
80
56
50
79
8
9
60
57
9
81
a All the reactions were conducted on a 1 mmol scale. b Isolated yields.
a All the reactions were conducted on a 1 mmol scale. b Isolated yields.
pounds in the synthesis of a number of useful compounds and
catalysts.20
2-propargyloxybenzaldoximes. The results are shown in
Table 5. As can be seen, unsubstituted as well as substituted
2-propargyloxybenzaldoximes underwent smooth cyclization
to give the corresponding tricyclic isoxazole derivatives in
good to excellent yields. Similar to the allyl derivatives, the
presence of an electron-withdrawing group (22a) also results in
a decreased yield. Interestingly, this method is also amenable
to the synthesis of tetracyclic isoxazoles (23a). Similar to the
data shown in Table 1, a very small amount of deoximination
product (<3%) was observed in the cases of entries 1 to 3 in
Table 5. The extent of deoximination is slightly higher in the
case of 5-Cl (Table 5, entry 4).
The substrates, 24 and 25, were prepared by a 5-step process
using literature procedures starting from diacetone glucose
(Scheme 1). In the first step, diacetone glucose was alkylated by
treatment with NaH and allyl/propargyl bromide in anhydrous
THF.21 The resulting allyl/propargyl diacetone glucose was
treated with 2 N H2SO4 in methanol to selectively remove
the isopropylidene group at the 1,2-position to obtain the
corresponding diol.22 Oxidative cleavage of the diol to the
corresponding aldehyde was achieved by treatment with silica-
supported NaIO4 in dichloromethane.23 The resulting aldehyde
was further converted to the corresponding oxime (24, 25)
by treatment with NH2OH·HCl and NaHCO3 in ethanol
at 70 ◦C. These allyl (24), and propargyloxime (25) deriva-
tives were converted to furopyrano-2-isoxazoline (24a) and
To further extend the scope of our methodology, we applied
the method to the synthesis of furopyrano-2-isoxazolines and
furopyrano-2-isoxazoles, which are important precursor com-
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Table 5 HTIB-mediated synthesis of tricyclic isoxazole derivatives
under ‘on-water’ conditionsa
Entry
1
Aldoxime
Product
Yield (%)b
88
2
3
74
89
Scheme 1 Synthesis of furopyrano-2-isoxazoline and furopyrano-2-
isoxazole.
4
5
72
69
Fig. 3 Crystal structure of compound 25a.
1H NMR spectroscopy was used to gain further insights into
the reaction. In this experiment the intensity of the initially
formed PhI+OH peak decreased with time and completely
disappeared after 45 min. (Fig. 4). In an earlier report,
a All the reactions were conducted on a 1 mmol scale. b Isolated yields.
Fig. 4 Spectra related to the 1H NMR experiment in D2O. (a) Just
after the addition of reagent to the starting material. The doublet at
8.31 ppm and the triplet at 7.85 ppm (assigned to PhI+OH) appear.
Another triplet, merged with the doublet for p-toluenesulfonic acid,
appears at 7.70 ppm. Minor peaks are due to starting material. (b)
12 min after the start of the reaction. The PhI+OH peak has decreased
drastically. (c) 45 min after the start of the reaction. The PhI+OH peaks
have completely disappeared. (d) Spectra of the crude mixture after the
1H NMR experiment, in CDCl3. The doublet at 7.72 ppm, triplet at 7.32
and 7.12 ppm are assigned to iodobenzene. The doublet of doublets at
7.41 ppm corresponds to the product peak.
Fig. 2 Crystal structures of (a) 14a, (b) 17a, (c) 16a.
furopyrano-2-isoxazole (25a) (Fig. 3) in good yield by the
present method. It should be noted that the acid-sensitive
isopropylidene group present in 24a and 25a remained intact.
No trace of side-products were detected in the crude 1H NMR
spectrum, except for a very small amount of deoximination.
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Ritcher and coworkers reported that HTIB ionises in aqueous
solution (its solubility is 0.024 g ml-1)24 to produce a (hy-
droxyl)phenyliodinium ion (PhI+OH). This type of ionisation
can be explained from the viewpoint of its structural feature,25
i.e., a weaker I–OTs bond is almost collinear with a stronger I–
OH bond. The PhI+OH formed in aqueous medium is probably
stabilized by the delocalization of lone pair of oxygen electrons
to the electron-deficient iodine centre, as shown in Scheme 2.
deoximination product was observed with the introduction of
an electron-withdrawing group (Table 3 and Table 5).
In order to defend this mechanism further, we can take into
account the resonance structure of intermediate C (Scheme 3).
This resonance decreases the electrophilicity of the carbon of
the CNO moiety. The presence of an electron-withdrawing
group lowers the efficiency of the resonance. A lower yield
of deoximination indicates a larger amount of nitrile oxide
formation. Hence, the presence of an electron-donating group at
the benzene ring is expected to increase the yield of the desired
isoxazoles (Table 3 and Table 5).
Scheme 3 Probable mechanistic routes for the deoximination.
To introduce more diversification, we considered the utility
of triazole compounds in medicinal chemistry and the great
interest of modern chemists in this field.28 To the best of our
knowledge, triazole derivatives of chrominoisoxazoles have not
been explored to any extent. Our approach consists of four steps
29c
(Scheme 4). Deacetylation of compound 15a with K2CO3
followed by mesitylation29a gives compound 15c. Heating 15c
◦
at 60 C with sodium azide in DMF29a produces 15d, which is
then amenable to a [3+2] cycloaddition with propargyl alcohol
using 5 mol% Cu(OAc)2 in water,29b producing the triazole
15e in excellent yield. Further study of these types of triazole
derivatives and the identification of biomedical applications is
ongoing in our laboratory.
Scheme 2 Plausible route for the formation of isoxazoline derivatives.
Based on our 1H NMR experiment and the previous studies,24
we propose a mechanistic route for the formation a nitrile oxide
under ‘on-water’ conditions (Scheme 2).
PhI+OH (A) is the active oxidizing species. The logic behind
this assumption is that the iodine center at PhI+OH is less
sterically demanding than HTIB. As a result, it enhances the
efficiency of the reactions that start with nucleophilic attack
at iodine. At this stage, the oxime, due to its high reactivity
and its a-effect,26 performs nucleophilic attack on the iodine
centre of PhI+OH resulting in the production of intermediate
B. This, upon protonation, undergoes the elimination of water
and iodobenzene and forms C. The abstraction of a proton
from C by TsO- produces a dipole, nitrile oxide, which un-
dergoes further intramolecular cyclization to give the tricyclic
isoxazoline or isoxazole. Although the medium and reaction
conditions are different, the initial step of the mechanism
appears to contradict the mechanism proposed by Maiti et al.,11c
who predicted nucleophilic attack by the oxygen of iodosyl
benzene, where our prediction is that the iodine center of the (hy-
droxyl)phenyliodonium ion (PhI+OH) undergoes nucleophilic
attack by the oxime oxygen. The nucleophilic attack of a water
molecule on intermediate C is probably the reason behind the
deoximination(Scheme2). This mechanism is also different from
that proposed by De et al.27
Scheme
4
The synthesis of (1-((3a,4-dihydro-3H-chromeno[4,3-
c]isoxazol-3-yl)methyl)-1H-1,2,3-triazol-4-yl)methanol.
Conclusions
In conclusion, we report a convenient and efficient method
for the synthesis of tricyclic isoxazoline and isoxazole deriva-
tives in good to excellent yields under ‘on-water’ condi-
tions. Our methodology is equally applicable to preparing
benzopyran-, naphthopyran- and even furopyrano-isoxazoles
and -isoxazolines. A mechanism is proposed for the reaction
based on 1H NMR data, which is consistent with related
observations from the literature. The reaction conditions are
simple and the reagent used, HTIB, is stable in air and in the
presence of moisture, readily available, and can be handled
without any special care. Apart from these advantages, this
Our proposed mechanism accounts for the observations
regarding deoximination. An electron-poor benzene ring pro-
motes nucleophilic attack at the carbon of the CNO moiety of
intermediate C and vice versa. Hence, an increase in the yield of
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methodology is a milder, more environmentally friendly, and
more cost-effective alternative to existing protocols.
3 (a) J. I. Andres-Gil, J. M. Bartolome-Nebreda, M. J. Alcazar-Vaca,
M. d. l. M. Gracia-Martin and A. A. H. P. Megens, US Pat. Appl.
2008/0113988 A1, 2008; (b) J. I Andre´s, J Alca´zar, J. M. Alonso,
R. M. Alvarez, M. H. Bakker, I Biesmans, J. M. Cid, A. I. D. Lucas,
W. Drinkenburg, J Ferna´ndez, L. M. Font, L. Iturrino, X. Langlois,
I. Lenaerts, S. Martı’nez, A. A. Megens, J Pastor, S. Pullan and T.
Steckler, Bioorg. Med. Chem., 2007, 15, 3649; (c) J Pastor, J Alca´zar,
R. M. Alvarez, J. I Andre´s, J. M. Cid, A. I. D. Lucas, A D´ıaz, J
Ferna´ndez, L. M. Font, L Iturrino, C Lafuente, S Mart´ınez, M. H.
Bakker, I Biesmans, L. I. Heylen and A. A. Megens, Bioorg. Med.
Chem. Lett., 2004, 14, 2917; (d) J. I Andres, J Alcazar, J. M. Alonso,
R. M. Alvarez, J. M. Cid, A. I. D. Lucas, J Ferna´ndez, S. Martı’nez,
C Nieto, J Pastor, M. H. Bakker, I Biesmans, L. I. Heylen and A. A.
Megens, Bioorg. Med. Chem. Lett., 2003, 13, 2719.
4 (a) G. Broggini, F. Folcio, N. Sardone, M. Sonzogni and G. Zecchi,
Tetrahedron: Asymmetry, 1996, 7, 797; (b) A. E. Kella-Bennani, M.
Soufiaoui, A. Kerbal, S. Fkih-Tetouaniz and N. Bitit, Tetrahedron,
1995, 51, 10923.
5 V. Jaeger and P. A. Colinas, ‘Nitrile Oxides’, in Synthetic Applications
of 1,3-Dipolar Cycloaddition Chemistry Toward Heterocycles and
Natural Products, ed. A. Padwaa and W. H. Pearson, Chemistry
of Heterocyclic Compounds, Wiley, Hoboken, 2002, vol. 59, p. 361.
6 (a) E. Trogu, F. D. Sarlo and F. Machetti, Chem. Eur. J., 2009, 15,
7940; (b) A. V. Baranovsky, D. A. Bolibrukh and J. R. Bull, Eur. J. Org.
Chem., 2007, 445; (c) F. Machetti, L. Cecchi, E. Trogu and F. D. Sarlo,
Eur. J. Org. Chem., 2007, 4352.
Experimental
General procedure for oxidative [3+2] cycloaddition
To a 50 ml beaker containing oxime derivative (1 mmol) in
2 ml of water, small portions of [hydroxy(tosyloxy)iodo]benzene
(1.1 mmol) were added with continuous stirring for a 45 min
period. After the addition was complete, the stirring was con-
tinued for an additional 5 min. The crude product precipitated,
isolated by filtration and washed with water. In the case of an
oily product, the reaction mixture was quenched with sodium
bicarbonate and the reaction mixture was extracted with ethyl
acetate (2 ¥ 10 mL). The organic layer was separated, dried over
anhydrous sodium sulfate and concentrated to give the crude
product. The crude product was passed through a short column
to furnish the pure product.
´
´
7 (a) S. Gao, Z. Tu, C.-W. Kuo, J.-T. Liu, C.-M. Chu and C.-F. Yao,
Org. Biomol. Chem., 2006, 4, 2851; (b) Z. Tu, Y. Jang, C. Lin, J.-T.
Liu, J. Hsu, M. N. V. Sastry and C.-F. Yao, Tetrahedron, 2005, 61,
10541; (c) J.-T. Liu, W.-W. Lin, J.-J. Jang, J.-Y. Liu, M.-C. Yan, C.
Hung, K.-H. Kao, Y. Wang and C.-F. Yao, Tetrahedron, 1999, 55,
7115; (d) M.-C. Yan, J.-Y. Liu, W.-W. Lin, K.-H. Kao, J.-T. Liu, J.-J.
Jang and C.-F. Yao, Tetrahedron, 1999, 55, 12493.
Acknowledgements
We would like to express our sincere gratitude to the National
Science Council of the Republic of China and National Taiwan
Normal University for providing financial support to pursue
this work. MJR is grateful to MOFA for a Taiwan Scholarship.
8 (a) N. L. Fraefel and E. M. Carreira, Chem. Eur. J., 2009, 15, 12065;
(b) L. R. Domingo, E. Chamorro and P. Pe´rez, Eur. J. Org. Chem.,
2009, 3036; (c) V. Singh, V. Singh and S Batra, Eur. J. Org. Chem.,
2008, 5446; (d) S. Grecian and V. V. Fokin, Angew. Chem., Int. Ed.,
2008, 47, 8285; (e) R. Herrera, J. A. Mendoza, M. A. Morales,
F. Me´ndez, H. A. Jime´nez-Va´zquez, F. Delgado and J. Tamariz,
Eur. J. Org. Chem., 2007, 2352; (f) H. Yamamoto, S. Hayashi, M.
Kubo, M. Harada, M. Hasegawa, M. Noguchi, M. Sumimoto and
K. Hori, Eur. J. Org. Chem., 2007, 2859; (g) L. Barr, S. F. Lincoln
and C. J. Easton, Chem. Eur. J., 2006, 12, 8571; (h) G. Giorgi, L. R.
Lampariello, G. Minetto, M. L. Paoli, V. Riello, M. Rodriquez and
A. Sega, Eur. J. Org. Chem., 2003, 4777; (i) C. Roussel, R Fihi, K.
Ciamala, P. Audebert and J. Vebrel, New J. Chem., 2000, 24, 471;
(j) G. Adembri, G. Giorgi, R. L. Lampariello, M. L. Paoli and A.
Sega, J. Chem. Soc., Perkin Trans. 1, 2000, 2649.
9 (a) N. Becker and E. M. Carreira, Org. Lett., 2007, 9, 3857; (b) L.
Perez, M. E. E. Khouly, P. D. L. Cruz, Y. Araki, O. Ito and F.
Langa, Eur. J. Org. Chem., 2007, 2175; (c) A. Nivlet, L. Dechoux,
J. P. Martel, G. Proess, D. Mannes, L. Alcaraz, J. J. Harnett, T. L.
Gall and C Mioskowski, Eur. J. Org. Chem., 1999, 3241; (d) R. E.
Sammelson, R. B. Miller and M. J. Kurth, J. Org. Chem., 2000, 65,
2225.
10 (a) V. V. Vaidya, K. S. Wankhede, M. M. Salunkhe and G. K. Trivedi,
Synth. Commun., 2008, 38, 2392; (b) T. Liaskopoulos, S. Skoulika,
P. G. Tsoungas and G. Vavounis, Synthesis, 2008, 711; (c) J. I. Andre´s,
J. Alca´zar, J. M. Alonso, A. I. D. Lucas, L. Iturrino, I. Biesmansb
and A. A. Megens, Bioorg. Med. Chem., 2006, 14, 4361; (d) K. Bala
and H. C. Hailes, Synthesis, 2005, 3423; (e) J. I. Andres, J. Alcazar,
J. M. Alonso, R. M. Alvarez, M. H. Bakker, I. Biesmans, J. M. Cid,
A. I. D. Lucas, J. Fernandez, L. M. Font, K. A. Hens, L. Iturrino, I.
Lenaerts, S. Mart´ınez, A. A. Megens, J. Pastor, P. C. M. Vermote and
T. Steckler, J. Med. Chem., 2005, 48, 2054; (f) J. I. Lee, H. S. Lee and
B. H. Kim, Synth. Commun., 1996, 26, 3201; (g) M. Scobie, M. F.
Mahon and M. D. Threadgill, J. Chem. Soc., Perkin Trans. 1, 1994,
203; (h) O. Tsuge, K. Ueno and S. Kanemasa, Chem. Lett., 1984, 285;
(i) G. A. Lee, Synthesis, 1982, 508.
11 (a) J. L. Frie, C. S. Jeffrey and E. J. Sorensen, Org. Lett., 2009, 11, 5394
(DIB); (b) B. A. Mendelsohn, S. Lee, S. Kim, F. Teyssier, V. S. Aulakh
and M. A. Ciufolini, Org. Lett., 2009, 11, 1539 (DIB); (c) S. Bhosale, S.
Kurhade, U. V. Prasad, V. P. Palle and D. Bhuniya, Tetrahedron Lett.,
2009, 50, 3948 (MagtrieveTM (CrO2)); (d) N. Chatterjee, P. Pandit,
S. Halder, A. Patra and D. K. Maiti, J. Org. Chem., 2008, 73, 7775
References
1 (a) P. P. Shao, F. Ye, A. E. Weber, X. Li, K. A. Lyons, W. H. Parsons,
M. L. Garcia, B. T. Priest, M. M. Smith, J. P. Felix, B. S. Williams,
G. J. Kaczorowski, E. McGowan, C. Abbadie, W. J. Martin, D. R.
McMasters and Y. D. Gao, Bioorg. Med. Chem. Lett., 2009, 19,
5334; (b) S. Tapadar, R. He, D. N. Luchini, D. D. Billadeau and A. P.
Kozikowski, Bioorg. Med. Chem. Lett., 2009, 19, 3023; (c) J. Y. Bass,
R. D. Caldwell, J. A. Caravella, L. Chen, K. L. Creech, D. N. Deaton,
K. P. Madauss, H. B. Marr, R. B. McFadyen, A. B. Miller, D. J. Parks,
D. Todd, S. P. Williams and G. B. Wisely, Bioorg. Med. Chem. Lett.,
2009, 19, 2969; (d) Y. S. Lee, S. M. Park and B. H. Kim, Bioorg.
Med. Chem. Lett., 2009, 19, 1126; (e) C. Jin, H. A. Navarro, K. Page
and F. I. Carroll, Bioorg. Med. Chem., 2008, 16, 6682; (f) D. Simoni,
R. Rondanin, R Baruchello, M. Rizzi, G. Grisolia, M. Eleopra, S.
Grimaudo, A. D. Cristina, M. R. Pipitone, M. R. Bongiorno, M.
Arico, F. P. Invidiata and M. Tolomeo, J. Med. Chem., 2008, 51,
4796; (g) A. M. D Palma, I. Vliegen, E. D. Clercq and J. Neyts,
Med. Res. Rev., 2008, 28, 823; (h) V. E. Kuz’min, A. G. Artemenko,
E. N. Muratov, I. L. Volineckaya, V. A. Makarov, O. B. Riabova, P.
Wutzler and M. Schmidtke, J. Med. Chem., 2007, 50, 4205; (i) B. L.
Deng, T. L. Hartman, R. W. Buckheit, Jr., C. Pannecouque, E. D.
Clercq and M. Cushman, J. Med. Chem., 2006, 49, 5316; (j) C.
Dallanoce, P. Bazza, G. Grazioso, M. D. Amici, C. Gotti, L. Riganti,
F. Clementi and C. D. Micheli, Eur. J. Org. Chem., 2006, 3746; (k) A.
Makaritis, D. Georgiadis, V. Dive and A. Yiotakis, Chem. Eur. J,
2003, 9, 2079; (l) T. Nakamura, M. Sato, H. Kakinuma, N. Miyata,
K. Taniguchi, K. Bando, A. Koda and K. Kameo, J. Med. Chem.,
2003, 46, 5416; (m) B. B. Shankar, D. Y. Yang, S. Girton and A. K.
Ganguly, Tetrahedron Lett., 1998, 39, 2447; (n) A. P. Kozikowski,
Acc. Chem. Res., 1984, 17, 410. and references therein.
2 (a) Y. Koyama, R. Yamaguchi and K. Suzuki, Angew. Chem., Int.
Ed., 2008, 47, 1084; (b) H. Takikawa, A. Takada, K. Hikita and
K. Suzuki, Angew. Chem., Int. Ed., 2008, 47, 7446; (c) T. M. V. D.
Pinho and e Melo, Curr. Org. Chem., 2005, 9, 925; (d) S. Akai, K.
Tanimoto, Y. Kanao, S. Omura and Y. Kita, Chem. Commun., 2005,
2369; (e) B. H. Kim, Y. J. Chung and E. J. Ryu, Tetrahedron Lett.,
1993, 34, 8465; (f) D. P. Curran and B. H. Kim, Synthesis, 1986, 312;
(g) A. P. Kozikowski and P. D. Stein, J. Am. Chem. Soc., 1982, 104,
4023.
This journal is
The Royal Society of Chemistry 2010
Green Chem., 2010, 12, 1090–1096 | 1095
©

View Article Online
(PhIO/CTAB); (e) T. K. M. Shing, W. F. Wong, H. M. Cheng, W. S.
Kwok and K. H. So, Org. Lett., 2007, 9, 753 (chloramine-T); (f) G. G.
Tsantali, J. Dimtsas, C. A. Tsoleridis and I. M. Takakis, Eur. J. Org.
Chem., 2007, 258 (chloramine-T); (g) B. Das, H. Holla, G. Maheder,
K. Ventaeswarlu and B. P. Bandgar, Synthesis, 2005, 1572 (DIB);
(h) B. Das, G. Mahender, H. Holla and J. Banerjee, Arkivoc, 2005, 27
(CAN); (i) N. Arai, M. Iwakoshi, K. Tanabe and K. Narasaka, Bull.
Chem. Soc. Jpn., 1999, 72, 2277 (CAN); (j) A. Pal, A. Bhattacharjee
and A. Bhattacharjya, Synthesis, 1999, 1569 (chloramine-T); (k) A. S.
Radhakrishna, K. Sivaprakash and B. B. Singh, Synth. Commun.,
1991, 21, 1625 (PhICl2); (l) J. N. Kim and E. K. Ryu, Synth. Commun.,
1990, 20, 1373 (NCBT); (m) A. Hassner and K. M. L. Rai, Synthesis,
1989, 57 (chloramine-T).
Zhao, L. Wen, W. Cao, S. Zhang and H. Yang, J. Heterocycl. Chem.,
2005, 42, 209; (h) Y. Misu and H. Togo, Org. Biomol. Chem., 2003, 1,
1342; (i) T. Patonay, A. Levai, E. Riman and R. S. Varma, Arkivoc,
2004, vi, 183; (j) J. C. Lee, H. J. Choi and Y. C. Lee, Tetrahedron
Lett., 2003, 44, 123; (k) E. Miyazawa, T. Sakamoto and Y. Kikugawa,
J. Org. Chem., 2003, 68, 5429; (l) Y. Kawamura, M. Maruyama, T.
Tokuoka and M. Tsukayama, Synthesis, 2002, 2490; (m) J. C. Lee,
H.-J. Park and J. Y. Park, Tetrahedron Lett., 2002, 43, 5661; (n) S. T.
Handy and M. Okello, Synlett, 2002, 489; (o) O. Prakash, N. Saini
and P. K. Sharma, Heterocycles, 1994, 38, 409.
18 (a) L. F. Silva Jr., R. S. Vasconcelos and M. A. Nogueira, Org. Lett.,
2008, 10, 1017; (b) L. F. Silva, Jr., F. A. Siqueira, E. C. Pedrozo,
F. Y. M. Vieira and A. C. Doriguetto, Org. Lett., 2007, 9, 1433;
(c) M. M. Hossain, T. Tokuoka, K. Yamashita, Y. Kawamura and
M. Tsukayama, Synth. Commun., 2006, 36, 1201; (d) O. Prakash, A.
Kumar, A. K. Sadana and S. P. Singh, Synthesis, 2006, 21; (e) M. W.
Justik and G. F. Koser, Molecules, 2005, 10, 217; (f) M. W. Justik and
G. F. Koser, Tetrahedron Lett., 2004, 45, 6159.
19 (a) H. Ghosh and B. K. Patel, Org. Biomol. Chem., 2010, 8, 384;
(b) J. C. Lee, J. Y. Lee and S. J. Lee, Tetrahedron Lett., 2004, 45, 4939;
(c) M. Xia and Z.-C. Chen, Synth. Commun., 1997, 27, 1315.
20 (a) T. K. M. Shing and G. Y. C. Leung, Tetrahedron, 2002, 58, 7545;
(b) A. Pal, A. Bhattacharjya and R. Mukhopadhyay, Tetrahedron
Lett., 2000, 41, 10135; (c) A. Pal, A. Bhattacharjee, A. Bhattacharjya
and A. Patra, Tetrahedron, 1999, 55, 4123; (d) T. K. M. Shing,
W.-C. Fung and C.-H. Wong, J. Chem. Soc., Chem. Commun., 1994,
449; (e) S. Dutta, P. Chattopadhyay, R. Mukhopadhyay and A.
Bhattacharjya, Tetrahedron Lett., 1993, 34, 3588.
12 (a) U. M. Lindstro¨m, Organic reactions in water: Principles, Strategies
and Applications, Blackwell, New York, 2007; (b) M. C. Pirrung,
Chem. Eur. J., 2006, 12, 1312; (c) C.-J. Li, Chem. Rev., 2005, 105,
3095; (d) U. M. Lindstro¨m, Chem. Rev., 2002, 102, 2751; (e) K. Shu
and M. Kei, Acc. Chem. Res., 2002, 35, 209; (f) C.-J. Li, T. H. Chang,
Organic Reactions in Aqueous Media, Wiley, New York, 1997, p. 7950;
(g) R. Breslow, Acc. Chem. Res., 1991, 24, 159.
13 (a) G. Stavber, J. Iskra, M. Zupan and S. Stavber, Green Chem., 2009,
11, 1262; (b) S. Tiwari and A. Kumar, J. Phys. Chem. A, 2009, 113,
13685; (c) S. A. Ohnmacht, P. Mamone, A. J. Culshaw and M. F.
Greaney, Chem. Commun., 2008, 1241; (d) S. Tiwari and A. Kumar,
Chem. Commun., 2008, 4445; (e) C. Santi, S. Santoro, B. Battistelli,
L. Testaferri and M. Tiecco, Eur. J. Org. Chem., 2008, 5387; (f) F.
Wang, H. Fu, Y. Jiang and Y. Zhao, Adv. Synth. Catal., 2008, 350,
1830; (g) Q.-Y. Zhang, B.-K. Liu, W.-Q. Chen, Q. Wu and X.-F.
Lin, Green Chem., 2008, 10, 972; (h) M. C. Pirrung, K. D. Sarma
and J. Wang, J. Org. Chem., 2008, 73, 8723; (i) A. K. Chakraborti,
S. Rudrawar, K. B. Jadhav, G. Kaur and S. V. Chaneshwara, Green
Chem., 2007, 9, 1335; (j) S. Guizzetti, M. Benaglia, L. Raimondi and
G. Celentano, Org. Lett., 2007, 9, 1247; (k) Y. Jung and R. A. Marcus,
J. Am. Chem. Soc., 2007, 129, 5492; (l) A. Podgorsˆek, S. Stavber, M.
Zupan and J. Iskra, Green Chem., 2007, 9, 1212; (m) B. K. Price and
J. M. Tour, J. Am. Chem. Soc., 2006, 128, 12899; (n) H. B. Zhang, L.
Liu, Y. J. Chen, D. Wang and C.-J. Li, Eur. J. Org. Chem., 2006, 869;
(o) D. Gonzalez-Cruz, D. Tejedor, P. deArmas, E. Q. Morales and
F. Garcia-Tellado, Chem. Commun., 2006, 2798; (p) M. Carril, R.
SanMartin, I. Tellitu and E. Dom´ınguez, Org. Lett., 2006, 8, 1467;
(q) S. Narayan, J. Muldoon, M. G. Finn, V. V. Fokin, H. C. Kolb
and K. B. Sharpless, Angew. Chem., Int. Ed., 2005, 44, 3275; (r) J. E.
Klijin and J. B. F. N. Engberts, Nature, 2005, 435, 746.
21 C. V. Ramana and S. B. Suryawanshi, Tetrahedron Lett., 2008, 49,
445.
22 A. B. Smith, R. A. Rivero, K. J. Hale and H. A. Vaccaro, J. Am.
Chem. Soc., 1991, 113, 2092.
23 Y.-L. Zhong and T. K. M. Shing, J. Org. Chem., 1997, 62,
2622.
24 H. W. Richter, B. R. Cherry, T. Z. Zook and G. F. Koser, J. Am.
Chem. Soc., 1997, 119, 9614.
25 V. V. Zhdankin and P. J. Stang, Chem. Rev., 2008, 108, 5299.
26 (a) T. J. Dale, Jr. and J. Rebek, Angew. Chem., Int. Ed., 2009, 48,
7850; (b) Y. Ren and H. Yamataka, J. Org. Chem., 2007, 72, 5660;
(c) G. Klopman, K. Tsuda, J. B. Louis and R. E. Davis, Tetrahedron,
1970, 26, 4549; (d) J. O. Edwards and R. G. Pearson, J. Am. Chem.
Soc., 1962, 84, 16; (e) W. P. Jencks and J. Carriuolo, J. Am. Chem.
Soc., 1960, 82, 1778.
14 (a) A. Chanda and V. V. Fokin, Chem. Rev., 2009, 109, 725; (b) D.
Gonzsles-Cruz, D. Tejedor, P. de Armas and F. Garcia-Telaldo,
Chem. Eur. J., 2007, 13, 4823.
15 (a) D. K. Barange, V. Kavala, B. R. Raju, C.-W. Kuo, C. Tseng, Y.-C.
Tu and C.-F. Yao, Tetrahedron Lett., 2009, 50, 5116; (b) P. M. Habib,
V. Kavala, B. R. Raju, C.-W. Kuo and C.-F. Yao, Eur. J. Org. Chem.,
2009, 4503; (c) P. M. Habib, V. Kavala, C.-W. Kuo and C.-F. Yao,
Tetrahedron Lett., 2008, 49, 7005.
16 (a) D. Kumar, M. S. Sundaree, G. Patel, V. S. Rao and R. S. Varma,
Tetrahedron Lett., 2006, 47, 8239; (b) D. Kumar, M. S. Sundaree and
V. S. Ra o , Synth. Commun., 2006, 36, 1893; (c) O. Prakash, K. Pannu,
R. Prakash and A. Batra, Molecules, 2006, 11, 523; (d) D.-B. Wan
and J.-M. Chen, J. Chem. Res., 2006, 32, 7; (e) T. Nabana and H.
Togo, J. Org. Chem., 2002, 67, 4362; (f) G. F. Koser, Aldrichim. Acta,
2001, 34, 89.
17 (a) Y. Kawano and H. Togo, Synlett, 2008, 217; (b) N. N. Karade, S. V.
Gampawar, J. M. Kondre and S. V. Shinde, Tetrahedron Lett., 2008,
49, 4402; (c) J. C. Lee, J.-W. Seo and J. W. Baek, Synth. Commun.,
2007, 37, 2159; (d) S. J. Walker and D. J. Hart, Tetrahedron Lett., 2007,
48, 6214; (e) R. Aggarwal and G. Sumran, Synth. Commun., 2006,
36, 875; (f) Y.-Y. Xie, Synth. Commun., 2005, 35, 1741; (g) M. Li, G.
27 S. K. De and A. K. Mallik, Tetrahedron Lett., 1998, 39, 2389.
28 (a) P. M. Habib, B. R. Raju, V. Kavala, C.-W. Kuo and C.-F. Yao,
Tetrahedron, 2009, 65, 5799; (b) F. Amblard, J. H. Cho and R. F.
Schinazi, Chem. Rev., 2009, 109, 4207; (c) M. Meldal and C. W.
Tornøe, Chem. Rev., 2008, 108, 2952; (d) Y. Bourne, H. C. Kolb,
Z. Radic, K. B. Sharpless, P. Taylor and P. Marchot, Proc. Natl.
Acad. Sci. U. S. A., 2004, 101, 1449; (e) S. Palhagen, R. Canger, O.
Henriksen, J. A. van Parys, M. E. Riviere and M. A. Karolchyk,
Epilepsy Res., 2001, 43, 115; (f) C. F. T. Joan, H. Elizabeth, M.
Beatrice and P. B. Daniel, Antimicrob. Agents Chemother., 1998,
42, 313; (g) W. Fan, in Comprehensive Heterocyclic Chemistry II,
ed. A. R. Katritzky, C. W. Rees and E. F. V. Scriven, Pergamon,
Oxford, UK, 1996, vol. 4; (h) R. Alvarez, S. Velazquez, A. S. Felix,
S. Aquaro, E. D. Clercq, C.-F. Perno, A. Karlsson, J. Balzarini and
M. J. Camarasa, J. Med. Chem., 1994, 37, 4185; (i) D. R. Buckle,
C. J. M. Rockell, H. Smith and B. A. Spicer, J. Med. Chem., 1986,
29, 2262 and references therein.
29 (a) W. Pilgrim and P. V. Murphy, Org. Lett., 2009, 11, 939; (b) W. S.
Brotherton, H. A. Michaels, J. T. Simmons, R. J. Clark, N. S. Dalal
and L. Zhu, Org. Lett., 2009, 11, 4954; (c) R. W. Watts, M. Siegel and
C. Khosla, J. Med. Chem., 2006, 49, 7493.
1096 | Green Chem., 2010, 12, 1090–1096
This journal is
The Royal Society of Chemistry 2010
©