Dess-martin periodinane mediated intramolecular cyclization of phenolic azomethines: A solution-phase strategy toward benzoxazoles and benzothiazoles

Article abstract of DOI:10.1055/s-0029-1217136

Dess-Martin periodinane (DMP), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the intramolecular cyclization of phenolic azomethines/Schiff bases at ambient temperature leading to the rapid and expeditious synthesis of substituted benzoxazoles and benzothiazoles. Furthermore, a solution-phase strategy has been developed by treating the reaction mixtures sequentially with Amberlyst A-26 thiosulfate resin and diisopropylaminomethyl resin (PS-DIEA), which remove excess reagent and byproducts, to give pure products. Georg Thieme Verlag Stuttgart - New York.

Full text of DOI:10.1055/s-0029-1217136

398
SHORT PAPER
Dess–Martin Periodinane Mediated Intramolecular Cyclization of Phenolic
Azomethines: A Solution-Phase Strategy toward Benzoxazoles and
Benzothiazoles
S
ubstituted Benzox
.
a
zoles and B
S
enzothiazolesubhas Bose,* Mohd. Idrees
Organic Chemistry Division III, Fine Chemicals Laboratory, Indian Institute of Chemical Technology, Hyderabad, Tarnaka 500 007, India
Fax +91(40)27160387; E-mail: dsb@iict.res.in; E-mail: bose_iict@yahoo.co.in
Received 21 September 2009; revised 9 October 2009
crobial salvianen8 (Figure 1). Recent medicinal chemistry
Abstract: Dess–Martin periodinane (DMP), a highly versatile hy-
applications of benzoxazoles include the reverse tran-
pervalent iodine(V) reagent, was found to efficiently mediate the in-
scriptase inhibitor L-697661,9 a potent and highly selec-
tramolecular cyclization of phenolic azomethines/Schiff bases at
ambient temperature leading to the rapid and expeditious synthesis
tive estrogen receptor b agonist ERB-04110 (under clinical
of substituted benzoxazoles and benzothiazoles. Furthermore, a so- development for rheumatoid arthritis and endometriosis),
lution-phase strategy has been developed by treating the reaction
and a selective antagonist for peroxisome proliferator-ac-
tivated g antagonist JTP-426467,11 which is useful in dia-
mixtures sequentially with Amberlyst A-26 thiosulfate resin and di-
isopropylaminomethyl resin (PS-DIEA), which remove excess re-
betic and osteoporosis mechanistic studies. Similarly, the
agent and byproducts, to give pure products.
benzothiazole structural motif has recently attracted con-
Key words: Dess–Martin periodinane, intramolecular cyclization,
siderable attention for the development of novel and se-
azomethines, benzoxazoles, benzothiazoles, solution-phase strate-
lective anticancer drug candidates (e.g., Phortess),12 and
gy
has been widely applied in the development of calcium
channel antagonists and orexin receptor antagonists, as
well as for antituberculotics, antiparasitics and chemilu-
In recent years, organic derivatives of hypervalent iodine
minescent agents, and photosensitizers.13 More recently,
reagents have become widely accepted as a promising
benzothiazoles and benzoxazoles have been shown to be
synthetic tool for the development of environmentally
promising tools for the development of in vivo biomarkers
benign oxidations and for the construction of carbon–
of b-amyloid deposits in the brain and would be useful for
the identification of individuals at risk of Alzheimer’s dis-
heteroatom and carbon–carbon bonds1 due to their low
toxicity, readily availability, mild reactivities, and ease of
ease.14
handling. The innovative work reported in 1983 by Dess
and Martin on the discovery of what became known as the
NO2
Dess–Martin periodinane (DMP),2 has opened the door to
O
O
O
a wide range of highly useful organic reactions, most sig-
nificantly the mild oxidation procedures that allow alco-
N
NH
N
O
N
Cl
H3CO
O
hols to be converted into the corresponding carbonyl
compounds.3 Investigations in our laboratory on the effi-
cient use of hypervalent iodine(V) reagents in medicinally
significant reactions have revealed a myriad of useful re-
actions.4 In continuation of this work, we herein report an
efficient intramolecular cyclization of phenolic azometh-
ines mediated by Dess–Martin periodinane that enables
the synthesis of substituted benzoxazoles and benzothiaz-
oles in high yields at ambient temperatures within 10–15
minutes.
JTP 426467
HO
UK-1
O
S
N
H
N
N
NH2
⋅2HCl
F
O
NH
(CH2)4NH2
Me
H
O
S
N
N
Phortess
orexin receptor antagonist
Benzoxazoles and benzothiazoles are an important class
of privileged heterocyclic structures that are found in bio-
logically active and medicinally significant compounds.
In particular, the benzoxazole ring system is found in va-
riety of biologically active natural products such as cyto-
toxic UK-1,5 microsomal triglyceride transfer protein
(MTP) inhibitors,5b Gram-positive antibacterial calcimy-
cin,6 antimycobacterial pseudopteroxazole,7 and antimi-
Figure 1 Structures of pharmaceutically important benzoxazoles
and benzothiazoles
Owing to the importance of benzoxazoles and benzothia-
zoles, several synthetic protocols have been developed for
their acquisition. In this direction, 2-arylbenzoxazoles are
generally synthesized either by coupling of carboxylic
acids with 2-aminophenol using strong acids, such as bo-
ric acid or polyphosphoric acid,15 or through the reaction
of 2-aminophenols with aldehydes and subsequent oxida-
tive cyclization of the imine intermediate using various
oxidants.16,17 On the other hand, 2-arylbenzothiazoles are
SYNTHESIS 2010, No. 3, pp 0398–0402
x
x
.
x
x
.2
0
0
9
Advanced online publication: 20.11.2009
DOI: 10.1055/s-0029-1217136; Art ID: Z20009SS
© Georg Thieme Verlag Stuttgart · New York

SHORT PAPER
Substituted Benzoxazoles and Benzothiazoles
399
commonly synthesized via Jacobson’s cyclization of In this direction, we found that Parlow et al. applied Am-
thiobenzanilides,18 reaction of benzyl disulfides with o- berlyst A-26 thiosulfate resin for the removal of DMP and
aminothiophenol, reaction of S-aryl thiobenzoate with its byproducts in the solution-phase combinatorial oxida-
arylhaloamines, radical cyclization of benzyne intermedi- tion of alcohols.21 Here, we sequentially used Amberlyst
ates, or Grignard reactions of arylisothiocyanates.19 We A-26 thiosulfate resin (obtained by the treatment of Am-
noticed that the efficient DMP-promoted intramolecular berlyst A-26 bromide with aqueous sodium thiosulfate so-
cyclization of phenolic Schiff bases could be used to gen-
Table 1 DMP-Promoted Oxidative Cyclization of Azomethines
erate both of these privileged heterocycles through a com-
mon route under mild and environmentally benign
Entry Product
Isolation Isolation Purity
method A method B (%)c
conditions, and envisioned that such an approach could be
applied in a solution-phase strategy to rapidly generate
lead candidates for a drug-discovery program.
(%)a
(%)b
O
This oxidative cyclization methodology uses azomethines
as starting materials, which can be obtained by the con-
densation of a variety of 2-aminophenols or 2-ami-
nothiophenols with substituted aromatic aldehydes in
methanol in the presence of catalytic K-10 montmorillo-
nite clay. The resulting azomethines undergo oxidative
cyclization in the presence of DMP at room temperature
in dichloromethane to generate 2-arylbenzoxazoles and 2-
arylbenzothiazoles in high yields within 10–15 minutes,
leaving no trace of the starting material (Scheme 1,
Table 1).
Cl
1
2
95
92
99
98
N
Cl
2a
O
N
92
89
O
2b
2c
O
N
3
4
9522
8523
90
84
95
95
CF3
O
N
XH
R2
X
DMP, CH2Cl2
R1
R1
OH
N
r.t., 10–15 min
N
R2
2
1
2d
X = S, O
O
N
Scheme 1 DMP-mediated intramolecular cyclization of azometh-
ines
5
6
90
91
86
88
92
98
O
2e
2f
Except for the excess reagent (DMP) and the reduced
form of the iodine(III) reagent formed during the reaction,
the intramolecular nature of the reaction meant that no ad-
ditional byproducts were formed. Encouraged by these re-
sults, we were interested in developing a solution-phase
strategy for the rapid generation of a library of benzothia-
zole compounds. For this to be possible, the prerequisite
was to remove the excess DMP and the byproduct io-
dine(III) in a high-throughput format. Among the various
purification methods available for solution-phase combi-
natorial synthesis, the treatment of reaction solutions with
ion-exchange resins has proven to be effective in the re-
moval of some acidic or basic byproducts and there is a re-
cent report demonstrating the applicability to a 96-well
format.20
O
N
t-Bu
O
N
7
90
85
94
O
O
2g
2h
2i
S
N
9424
9225
90
89
96
99
OMe
8
9
S
N
S
N
10
11
954a
91
82
98
96
I
2–
S2O3
N
O
excess DMP and
iodine(III)
+
2
OH
2–
A-26 (S2O3
)
2j
MeO
O
Me
Me
S
8818b
N
base-functionalized resin
N
sequestered
2k
a Product isolated by column chromatography.
b Crude yields after resin treatment.
PS-DIEA
N
c HPLC purity of compounds isolated by method B, determined by in-
tegration of peak areas at 255 nm without calibration.
Scheme 2 Schematic representation of the solution-phase strategy
Synthesis 2010, No. 3, 398–402 © Thieme Stuttgart · New York

400
D. S. Bose, M. Idrees
SHORT PAPER
OAc
AcO
OAc
I
O
DMP
H
XH
iodine(V)
X
X
ionic, concerted
fragmentation
X
N
R1
R1
R1
R1
O
R2
1b
R2
R2
N
H
N
N
– AcOH
R2
– AcOH
2
1
1a
OAc
AcO
I
X = O, S
O
O
Scheme 3 A plausible mechanism for the oxidative cyclization of azomethines mediated by Dess–Martin periodinane
lution) and a base-functionalized resin to sequester the fragmentation, gives the desired product 2 and the re-
byproducts from the reaction; the results were very im- duced byproduct of iodine(III); in a similar mechanism,
pressive. It was envisioned that the thiosulfate resin would the oxidation of secondary amines to form imines by the
reduce the Dess–Martin periodinane reagent and the hypervalent iodine(V) reagents has been reported in the
byproduct iodine(III) reagent to 2-iodobenzoic acid, literature.26 The excess iodine(V) and the byproduct io-
thereby allowing its sequestration with a base-functional- dine(III) are reduced by Amberlyst 26 thiosulfate resin to
ized resin e.g., diisopropylaminomethyl resin (PS-DIEA). iodine(I), i.e. 2-iodobenzoic acid, which was finally se-
As a general procedure for the solution-phase strategy, af- questered from the reaction mixture by treatment with the
ter completion of the DMP-mediated azomethine cycliza- base-functionalized resin (PS-DIEA) to obtain the pure
tion reaction (which was monitored by TLC), the reaction product (Scheme 2).
mixture was treated with the Amberlyst A-26 thiosulfate
In summary, it is one of our goals to broaden the applica-
resin. This leads to reduction of both the excess DMP and
bility of Dess–Martin periodinane for the generation of
its byproduct formed in the cyclization reaction to give 2-
biologically significant heterocycles and develop medici-
iodobenzoic acid [i.e. iodine(I)]. This acidic impurity was
nally relevant transformations. We described here an effi-
then removed from the reaction mixture by treatment with
cient conversion of phenolic Schiff bases by the DMP
diisopropylaminomethyl resin (PS-DIEA, a base func-
reagent to generate substituted benzoxazoles and ben-
tionalized resin) to obtain pure products (Scheme 2).
zothiazoles at ambient temperature within 10–15 minutes,
To explore the generality and scope of this process, di- in high yields. The conversion and its solution-phase strat-
verse substituted azomethines were submitted to the con- egy could be of high value in diversity-oriented synthesis
ditions described above to generate a range of substituted for the generation of functionalized and substituted ben-
benzoxazoles and benzothiazoles; the results are illustrat- zothiazole and benzoxazole libraries for lead generation
ed in Table 1. Among the hypervalent iodine reagents and SAR studies. To our knowledge, the current method
studied for this transformation [o-iodoxybenzoic acid is the first report of solution-phase generation of both ben-
(IBX), and iodosobenzene diacetate (DAIB)], DMP was zothiazoles and benzoxazoles via a common route.
found to be the most effective in terms of both conversion
and reaction rates. Azomethines with both electron-donat-
Column chromatography was performed using silica gel (Acme,
ing and electron-withdrawing groups showed high reac-
tivity with DMP and give similar yields. Furthermore,
azomethines containing heterocyclic systems could also
be used efficiently. This reaction is very clean, efficient
and involves a simple work-up procedure. Moreover, al-
ternative solvents such as acetonitrile, tetrahydrofuran
and methanol also proved to be effective. The feasibility
of this methodology has been successfully applied for the
synthesis of novel and highly functionalized library of
benzoxazoles and benzothiazoles with potent cytotoxic
activities, which will be discussed elsewhere.
60–120 mesh). Solvents for chromatography (n-hexane, cyclohex-
ane, EtOAc) were distilled prior to use. For analytical TLC, Merck
pre-coated silica gel 60 F-254 plates were used; the plates were vi-
sualized using UV light (254 nm). Melting points were obtained us-
ing a precision digital melting point Veego VMP-DS apparatus and
are uncorrected. 1H and 13C NMR spectra were recorded on either a
Bruker Avance 300 (300.132 MHz for 1H, 75.473 MHz for 13C), or
Varian FT-200MHz (Gemini) spectrometer in CDCl3. Chemicals
shifts (d) are reported in parts per million (ppm) relative to tetra-
methylsilane (TMS; d = 0.00 ppm) as an internal standard. Elemen-
tal analyses were performed on an Elementar Vario EL
microanalyzer. Low-resolution mass spectra (ESI-MS) and HRMS
were recorded on Quattro LC, Micromass, and Q STAR XL, Ap-
plied Biosystems respectively.
A plausible mechanism for the DMP-promoted cycliza-
tion of azomethines is presented in Scheme 3. It is pre-
sumed that an equilibrium exists between the Schiff base
1 and the cyclized oxazoline or thiazoline system 1a
formed in situ by the cyclization of the imine functionality
with the phenol or thiophenol moiety of the Schiff base.
Dess–Martin periodinane reacts with the secondary amine
of the cyclized oxazoline or thiazoline system to form the
transition-state 1b, which, upon oxidative ionic concerted
Substituted 2-Arylbenzothiazoles and 2-Arylbenzoxazoles
(2a–k); General Procedure
Dess–Martin periodinane (0.55 mmol) was added to a stirred solu-
tion of azomethine (0.5 mmol) in CH2Cl2 (2 mL) at r.t. The solution
was stirred for 10–15 min, until TLC indicated the reaction was
complete. Amberlyst 26 (S2O32–) resin was added and the mixture
was stirred vigorously on an orbital shaker for 5–6 h. Finally, PS-
DIEA resin was added to the mixture and agitated vigorously for 1–
Synthesis 2010, No. 3, 398–402 © Thieme Stuttgart · New York

SHORT PAPER
Substituted Benzoxazoles and Benzothiazoles
401
2 h. The reaction mixture was filtered and the polymer was rinsed
with CH2Cl2. The combined filtrate and washings were concentrat-
ed in vacuo to give pure products 2a–k (85–95%).
MS (EI): m/z (%) = 211 (100) [M+], 183 (24), 155 (6), 141 (25), 93
(50), 65 (56), 63(56), 40 (37).
2-[3-(2-Propynyloxy)phenyl]benzoxazole (2e)
Preparation of 1-[2-(3-Phenoxyphenyl)benzoxazol-5-yl]etha-
none (2g); Typical Procedure
Mp 61–63 °C.
1H NMR (300 MHz, CDCl3): d = 2.49–2.51 (t, J = 2.26 Hz, 1 H),
4.78–4.80 (d, J = 2.26 Hz, 2 H), 7.10–7.14 (dd, J1 = 8.31 Hz,
J2 = 3.77 Hz, 1 H), 7.29–7.35 (m, 2 H), 7.39–7.45 (t, J = 7.55 Hz,
2 H), 7.52–7.59 (m, 1 H), 7.71–7.77 (m, 1 H), 7.81–7.89 (m, 2 H).
13C NMR (75 MHz, CDCl3): d = 56.0, 75.9, 78.1, 110.5, 113.2,
118.8, 120.0, 120.9, 124.5, 125.1, 128.3, 130.0, 142.0, 150.7, 157.8,
162.6.
Dess–Martin periodinane (46.6 mg, 0.11 mmol) was added to a
stirred solution of the corresponding Schiff base (33.1 mg, 0.1
mmol) in CH2Cl2 (1 mL) at r.t. The solution was stirred for 10 min
until TLC indicated the cyclization was complete. Isolation by
method A involved standard column chromatography (EtOAc–hex-
ane, 1:3) to afford 2g as a colorless solid (29.6 mg, 90%).
Isolation by method B: After completion of the reaction, A-26
(S2O32–) resin (1.72 mmol/g; 0.54 g, 0.93 mmol) was added and the
mixture was stirred vigorously on an orbital shaker for 5–6 h. Final-
ly, PS-DIEA resin was added to the mixture and agitated vigorously
for 1–2 h. The reaction mixture was filtered and the polymer was
rinsed with CH2Cl2. The combined filtrate and washings were evap-
orated to give compound 2g.
MS (EI): m/z (%) = 249 (40) [M+], 248 (36) [M – 1], 182 (25), 160
(100), 131 (100), 103 (58), 77 (42), 64 (25), 40 (31.2).
2-(4-tert-Butylphenyl)benzoxazole (2f)
Mp 102–104 °C.
1H NMR (300 MHz, CDCl3): d = 1.38 (s, 9 H), 7.28–7.34 (m, 2 H),
7.48–7.57 (m, 3 H), 7.71–7.80 (m, 1 H), 8.12–8.18 (d, J = 9.06 Hz,
1 H).
13C NMR (75 MHz, CDCl3): d = 110.4, 119.8, 124.3, 124.4, 124.8,
125.8, 127.4, 142.1, 150.63, 155.0, 163.1.
MS (EI): m/z (%) = 251 (63) [M+], 236 (100), 147 (12), 63 (5).
Yield: 27.9 mg (85%); colorless solid; mp 89–91 °C.
1H NMR (300 MHz, CDCl3): d = 2.66 (s, 3 H), 6.98–7.21 (m, 4 H),
7.29–7.61 (m, 4 H), 7.82–8.05 (m, 3 H), 8.28–8.31 (d, J = 1.7 Hz,
1 H).
13C NMR (75 MHz, CDCl3): d = 26.7, 110.6, 117.6, 119.2, 120.9,
122.3, 122.4, 123.9, 125.9, 128.1, 130.0, 130.4, 134.3, 142.1, 153.6,
156.5, 158.0, 163.7, 197.0.
2-(4-Methoxyphenyl)benzothiazole (2h)
Mp 119–120 °C (Lit.24 121–122 °C).
MS (EI): m/z (%) = 329 (43) [M+], 315 (100), 287 (21), 142 (28), 92
(39), 63 (21).
1H NMR (300 MHz, CDCl3): d = 3.88 (s, 3 H), 6.93–6.99 (m, 2 H),
7.28–7.34 (m, 1 H), 7.40–7.46 (m, 1 H), 7.81–7.85 (m, 1 H), 7.96–
8.03 (m, 3 H).
2-(2,4-Dichlorophenyl)benzoxazole (2a)
Mp 127–130 °C.
MS (ESI): m/z (%) = 242 (100) [M + H]+.
1H NMR (300 MHz, CDCl3): d = 7.33–7.43 (m, 3 H), 7.55–7.62 (m,
2 H), 7.78–7.83 (m, 1 H), 8.12–8.17 (d, J = 9.06 Hz, 1 H).
13C NMR (75 MHz, CDCl3): d = 110.7, 120.5, 124.7, 124.8, 125.7,
127.4, 131.3, 132.5, 134.2, 137.5, 141.5, 150.5, 160.0.
MS (EI): m/z (%) = 241 (100) [M+], 225 (40), 198 (42), 69 (20), 63
(15).
2-(4-Methylphenyl)benzothiazole (2i)
Mp 82–84 °C (Lit.25 87–88 °C).
MS (EI): m/z (%) = 268 (8) [M + 4], 266 (64) [M + 2], 264 (100)
1H NMR (300 MHz, CDCl3): d = 2.42 (s, 3 H), 7.22–7.35 (m, 3 H),
7.40–7.46 (m, 1 H), 7.81–7.87 (d, J = 7.55 Hz, 1 H), 7.93–8.03 (m,
3 H).
[M+], 236 (10), 92 (10), 64 (44), 63 (50), 43 (15).
2-(3-Phenoxyphenyl)benzoxazole (2b)
Mp 82–83 °C.
MS (ESI): m/z (%) = 226 (100) [M + H].
1H NMR (400 MHz, CDCl3): d = 6.95–7.09 (m, 4 H), 7.21–7.31 (m,
4 H), 7.36–7.48 (m, 2 H), 7.62–7.68 (m, 1 H), 7.79 (s, 1 H), 7.88–
7.92 (m, 1 H).
Anal. Calcd for C14H11NS: C, 74.63; H, 4.92; N, 6.22; S, 14.23.
Found: C, 74.32; H, 4.78; N, 6.05; S, 14.15.
MS (EI): m/z (%) = 287 (100) [M+], 286 (88) [M – 1], 141 (13), 77
(30), 43 (25).
2-(3-Phenoxyphenyl)benzothiazole (2j)
Mp 87–88 °C.
1H NMR (300 MHz, CDCl3): d = 7.04–7.18 (m, 4 H), 7.35–7.53 (m,
5 H), 7.74–7.82 (m, 2 H), 7.89 (d, J = 7.5 Hz, 1 H), 8.06 (d, J = 8.3
Hz, 1 H).
13C NMR (75 MHz, CDCl3): d = 117.7, 119.1, 121.2, 121.6, 122.4,
123.4, 123.7, 125.3, 126.4, 129.9, 130.4, 135.1, 154.1, 156.9, 158.0.
2-[4-(Trifluoromethyl)phenyl]benzoxazole (2c)
Mp 146–147 °C (Lit.22 143–145 °C).
1H NMR (200 MHz, CDCl3): d = 7.32–7.42 (m, 2 H), 7.53–7.61 (m,
1 H), 7.75–7.84 (m, 4 H), 8.33–8.42 (d, J = 8.47 Hz, 1 H).
13C NMR (75 MHz, CDCl3): d = 110.7, 120.3, 121.9, 124.9, 125.8,
125.8, 125.9 (q, J = 4.4 Hz), 127.8, 129.8, 130.3, 131.2, 141.8,
150.8, 161.4.
MS (ESI): m/z (%) = 303 (100) [M+], 239 (25), 141 (10).
6-Methoxy-2-(4-dimethylami nophenyl)benzothiazole (2k)
Mp 178–180 °C.
MS (EI): m/z (%) = 263 (100) [M+], 262 (13) [M – 1], 235 (10), 63
1H NMR (300 MHz, CDCl3): d = 3.05 (s, 6 H), 3.86 (s, 3 H), 6.70
(d, J = 9.06 Hz, 2 H), 6.98 (dd, J = 9.06, 3.02 Hz, 1 H), 7.24–7.27
(m, 1 H), 7.80–7.88 (m, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 40.1, 55.8, 104.4, 111.7, 114.8,
121.6, 122.7, 128.5, 135.8, 148.9, 151.9, 157.0, 166.4.
(48).
2-(3-Hydroxyphenyl)benzoxazole (2d)
Mp 149–150 °C.
1H NMR (200 MHz, CDCl3): d = 6.96–7.12 (m, 1 H), 7.27–7.39 (m,
3 H), 7.52–7.75 (m, 4 H), 9.31 (br s, 1 H, OH).
MS (EI): m/z (%) = 284 (100) [M+], 269 (80), 253 (55), 241 (75),
149 (75), 95 (50), 85 (50), 43 (75).
Synthesis 2010, No. 3, 398–402 © Thieme Stuttgart · New York

402
D. S. Bose, M. Idrees
SHORT PAPER
(13) (a) Yildiz-Oren, I.; Yalcin, I.; Aki-Sener, E.; Ucarturk, N.
Eur. J. Med. Chem. 2004, 39, 291. (b) Mahran, M. A.; El-
Nassry, S. M. F.; Allam, S. R.; El-Zawawy, L. A. Pharmazie
2003, 58, 527. (c) Costa, S. P. G.; Batista, R. M. F.; Cardoso,
P.; Belsley, M.; Raposo, M. M. M. Eur. J. Org. Chem. 2006,
17, 3938. (d) Lopez-Calahorra, F.; Martinez-Rubio, M.;
Velasco, D.; Brillas, E.; Julia, L. Tetrahedron 2004, 60, 285.
(e) Ali, A.; Taylor, G. E.; Graham, D. W. PCT Int. Appl.,
WO 2001028561, 2001. (f) Bergman, J. M.; Coleman, P. J.;
Cox, C.; Hartman, G. D.; Lindsley, C.; Mercer, S. P.;
Roecker, A. J.; Whitman, D. B. PCT Int. Appl., WO
2006127550, 2006.
(14) (a) Mathis, C. A.; Wang, Y.; Holt, D. P.; Huang, G. F.;
Debnath, M. L.; Klunk, W. E. J. Med. Chem. 2003, 46,
2740. (b) Henriksen, G.; Hauser, A. I.; Westwell, A. D.;
Yousefi, B. H.; Schwaiger, M.; Drzezga, A.; Wester, H.-J.
J. Med. Chem. 2007, 45, 1087. (c) Mathis, C. A.; Bacskai,
B. J.; Kajdasz, S. T.; McLellan, M. E.; Frosch, M. P.;
Hyman, B. T.; Holt, D. P.; Wang, Y.; Huang, G.-F.;
Debnath, M. L.; Klunk, W. E. Bioorg. Med. Chem. Lett.
2002, 12, 295.
Acknowledgment
Md.I. thanks CSIR, New Delhi, for financial support.
References
(1) (a) Varvoglis, A.; Spyroudis, S. Synlett 1998, 221.
(b) Varvoglis, A. Hypervalent Iodine in Organic Synthesis;
Academic Press: San Diego, 1996, 256. (c) Wirth, T.; Hirt,
U. H. Synthesis 1999, 1271. (d) Nicolaou, K. C.; Baran, P.
S.; Zhong, Y.-L.; Sugita, K. J. Am. Chem. Soc. 2002, 124,
2221; and references cited therein. (e) Aggarwal, R.;
Sumran, G. Synth. Commun. 2006, 36, 875. (f) Wipf, P.;
Venkatraman, S. J. Org. Chem. 1996, 61, 8004.
(2) (a) Dess, D. B.; Martin, J. C. J. Org. Chem. 1983, 48, 4155.
(b) Dess, D. B.; Martin, J. C. J. Am. Chem. Soc. 1991, 113,
7277. (c) Meyer, S. D.; Schreiber, S. L. J. Org. Chem. 1994,
59, 7549.
(3) (a) Frigerio, M.; Santagostino, M.; Sputore, S.; Palmisano,
G. J. Org. Chem. 1995, 60, 7272. (b) Liu, Z.; Chen, Z.-C.;
Zheng, Q.-G. Org. Lett. 2003, 5, 3321. (c) More, J. D.;
Finney, N. S. Org. Lett. 2002, 4, 3001. (d) Mazitschek, R.;
Mullbaier, M.; Giannis, A. Angew. Chem. Int. Ed. 2002, 41,
4059.
(4) (a) Bose, D. S.; Idrees, Md. J. Org. Chem. 2006, 71, 8261.
(b) Bose, D. S.; Reddy, A. V. N. Tetrahedron Lett. 2003, 44,
3543. (c) Bose, D. S.; Srinivas, P.; Gurjar, M. K.
Tetrahedron Lett. 1997, 38, 5839.
(15) (a) Terashima, M.; Ishii, M.; Kanaoka, Y. Synthesis 1982,
484. (b) Hein, D. W.; Alheim, R. J.; Leavitt, J. J. J. Am.
Chem. Soc. 1957, 79, 427. (c) Bourgrin, K.; Loupy, A.;
Soufiaoui, M. Tetrahedron 1998, 54, 8055. (d) Pottorf, R.
S.; Chadha, N. K.; Katkevics, M.; Ozola, V.; Suna, E.;
Ghane, H.; Regberg, T.; Player, M. R. Tetrahedron Lett.
2003, 44, 175.
(16) (a) Park, K. H.; Jun, K.; Shin, S. R.; Oh, S. W. Tetrahedron
Lett. 1996, 37, 8869. (b) Srivastava, R. G.; Venkataramani,
P. S. Synth. Commun. 1988, 18, 1537. (c) Nakagawa, K.;
Onoue, H.; Sugita, J. Chem. Pharm. Bull. 1964, 12, 1135.
(d) Stephens, F. F.; Bower, J. D. J. Chem. Soc. 1949, 2971.
(e) Chang, J.; Zhao, K.; Pan, S. Tetrahedron Lett. 2002, 43,
951. (f) Prakash, O.; Batra, A.; Sharma, V.; Saini, R.;
Verma, R. S. J. Ind. Chem. 2003, 80, 1031.
(5) (a) Ueki, M.; Ueno, K.; Miyadoh, S.; Abe, K.; Shibata, K.;
Taniguchi, M.; Oi, S. J. Antibiot. 1993, 46, 1089. (b) Vu, C.
B.; Milne, J. C.; Carney, D. P.; Song, J.; Choy, W.; Lambert,
P. D.; Gagne, D. J.; Hirsch, M.; Cote, A.; Davis, M.; Lainez,
E.; Meade, N.; Normington, K.; Jirousek, M. R.; Perni, R. B.
Bioorg. Med. Chem. Lett. 2009, 19, 1416.
(6) Prudhomme, M.; Guyat, J.; Jeminet, G. J. Antibiotics 1986,
39, 934.
(17) Jones, C. P.; Anderson, K. W.; Buchwald, S. L. J. Org.
(7) (a) Rodriguez, A. D.; Ramirez, C.; Rodriguez, I. I.;
Gonzalez, E. Org. Lett. 1999, 1, 527. (b) Davidson, J. P.;
Corey, E. J. J. Am. Chem. Soc. 2003, 125, 13486.
(8) Don, M.-J.; Shen, C.-C.; Lin, Y.-L.; Syu, W. Jr.; Ding, Y.-
H.; Sun, C.-M. J. Nat. Prod. 2005, 68, 1066.
(9) Grobler, J. A.; Dornadula, G.; Rice, M. R.; Simcoe, A. L.;
Hazuda, D. J.; Miller, M. D. J. Biol. Chem. 2007, 282, 8005.
(10) Leventhal, L.; Brandt, M. R.; Cummons, T. A.; Piesla, M. J.;
Rogers, K. E.; Harris, H. A. Eur. J. Pharmacol. 2006, 553,
146.
Chem. 2007, 72, 7968; and references therein.
(18) (a) Shi, D.-F.; Bradshaw, T. D.; Wrigley, S.; McCall, C. J.;
Lelieveld, I. F.; Stevens, M. F. G. J. Med. Chem. 1996, 39,
3375. (b) Bose, D. S.; Idrees, Md.; Srikanth, B. Synthesis
2007, 819; and references cited therein.
(19) (a) Hein, D. W.; Alheim, R. J.; Leavitt, J. J. J. Am. Chem.
Soc. 1957, 79, 427. (b) Paul, S.; Gupta, M.; Gupta, R. Synth.
Commun. 2002, 32, 3541. (c) Shirinian, V. Z.; Melkova, S.
Yu.; Belen’kii, L. I.; Krayushkin, M. M.; Zelinsky, N. D.
Russ. Chem. Bull. 2000, 49, 1859. (d) Zhong, W. H.; Zhang,
Y. M.; Chen, X. Y. J. Indian Chem. Soc. 2001, 78, 316.
(e) Roe, A.; Tucker, W. P. J. Heterocycl. Chem. 1965, 2,
148. (f) Stanetty, P.; Krumpark, B. J. Org. Chem. 1996, 61,
5130. (g) Ares, J. J. Synth. Commun. 1991, 21, 625.
(20) Bookser, B. C.; Zhu, S. J. Comb. Chem. 2001, 3, 205.
(21) Parlow, J. J.; Case, B. L.; South, M. S. Tetrahedron 1999,
55, 6785.
(11) Nishiu, J.; Ito, M.; Ishida, Y.; Kakutani, M.; Shibata, T.;
Matsushita, M.; Shindo, M. Diabetes Obes. Metab. 2006, 8,
508.
(12) (a) Hutchinson, I.; Jennings, S. A.; Vishnuvajjala, B. R.;
Westwell, A. D.; Stevens, M. F. G. J. Med. Chem. 2002, 45,
744. (b) Mortimer, C. G.; Wells, G.; Crochard, J.-P.; Stone,
E. L.; Bradshaw, T. D.; Stevens, M. F. G.; Westwell, A. D.
J. Med. Chem. 2006, 49, 179. (c) Brantley, E. A.; Patel, V.
B.; Stinson, S. F. A.; Trapani, V. C.; Hose, D. D.; Ciolino,
H. P. E.; Yeh, G. C. E.; Gutkind, J. S. B.; Sausville, E. A. F.;
Loaiza-Perez, A. I. F. Anti-Cancer Drugs 2005, 16, 137.
(22) Lewis, J. C.; Wiedemann, S. H.; Bergman, R. G.; Ellman, J.
A. Org. Lett. 2004, 6, 35.
(23) Myllymaeki, M. J.; Kosikinen, A. M. P. Tetrahedron Lett.
2007, 48, 2295.
(24) Osman, A.-M.; Bassiouni, I. J. Org. Chem. 1962, 27, 558.
(25) Palmer, P. J.; Hall, G.; Trigg, R. B.; Warrington, J. V.
J. Med. Chem. 1971, 14, 1223.
(26) Nicolaou, K. C.; Mathison, C. J. N.; Montagnon, T. J. Am.
Chem. Soc. 2004, 126, 5192.
Synthesis 2010, No. 3, 398–402 © Thieme Stuttgart · New York