PPh3-catalyzed ring-expansion reactions of sulfamate-derived cyclic imines with acetylenedicarboxylates

Article abstract of DOI:10.1002/asia.201301082

The PPh₃-catalyzed ring-expansion reaction of sulfamate-derived cyclic imines with acetylenedicarboxylates has been developed. The reaction works quite efficiently under very mild conditions to afford benzo[g][1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-dioxide derivatives in high yields. Copyright

Full text of DOI:10.1002/asia.201301082

FULL PAPER
DOI: 10.1002/asia.201301082
PPh3-Catalyzed Ring-Expansion Reactions of Sulfamate-Derived Cyclic
Imines with Acetylenedicarboxylates
Zhilin Yang,[a] Hao Yu,[a] Lei Zhang,[a] Hang Wei,[a] Yumei Xiao,[a] Lanzhen Chen,[b] and
Hongchao Guo*[a]
Abstract: The PPh3-catalyzed ring-expansion reaction of sulfamate-derived cyclic
imines with acetylenedicarboxylates has been developed. The reaction works quite
efficiently under very mild conditions to afford benzo[g]ACTHNUTRGNEUG[N 1,2,3]oxathiazocine-4,5-di-
carboxylate 2,2-dioxide derivatives in high yields.
Keywords: heterocycles · imines ·
organocatalysis · ring expansion ·
synthetic methods
Introduction
Nucleophilic phosphine organocatalysis has seen much de-
velopment in the past few decades and has become a power-
ful tool for the synthesis of acyclic and cyclic compounds.[1]
Among various phosphine-catalyzed reactions, the annula-
tion reactions of electron-deficient olefins, allenes, and al-
kynes with activated imines[2] have received much attention
due to their extensive application in the synthesis of various
useful nitrogen-containing heterocycles[3] and natural prod-
ucts.[4] Compared with electron-deficient olefins and allenes,
alkynes were seldom used in annulation reactions with
imines, and only a few examples have been reported. In
1998, Lu and Zu reported Bu3P-catalyzed [3+2] cycloaddi-
tion of 2-butynoate with N-tosylimines (Scheme 1a) and
Ph3P-catalyzed [3+2] cycloaddition of dimethyl acetylenedi-
carboxylate with N-tosylimines (Scheme 1b).[2b] Both reac-
tions afforded pyrrolidine derivatives as products in high
yields. Ten years later, Xue and co-workers extended this
chemistry to Bu3P-catalyzed [3+2] cycloaddition of alkynyl
ketones with N-tosylimines providing highly functionalized
pyrrolidines in good to excellent yields with complete ste-
reoselectivity (Scheme 1a).[2n] For the reactions in
Scheme 1a, because the alkynes have a g-carbon atom, both
alkynyl ester and alkynyl ketone served as C3 synthons
under phosphine-catalysis conditions. In Scheme 1b, acetyle-
nedicarboxylate functioned as a C3 synthon in phosphine-
Scheme 1. Reactions of activated alkynes with activated imines.
catalyzed reactions with imines. In general, contrary to al-
kynyl esters with g-carbon atoms, acetylenedicarboxylate
acts as a C2 synthon in annulation reactions mediated by
Lewis bases.[1c]
Normally, the reaction of an acetylenedicarboxylate with
an electron-deficient imine would result in a [2+2] cycload-
duct. Since phosphine-catalyzed [2+2] cycloaddition reac-
tions are extremely rare,[5] it is very attractive to investigate
[2+2] cycloaddition of acetylenedicarboxylates with cyclic
imines as a new type of annulation reaction. Moreover,
phosphine-catalyzed annulation of activated alkynes with
cyclic imines has never been reported. On the other hand,
[a] Z. Yang, H. Yu, L. Zhang, H. Wei, Dr. Y. Xiao, Dr. H. Guo
Department of Applied Chemistry
Institution China Agricultural University
2 West Yuanmingyuan Road, Beijing 100193 (China)
Fax : (+86)10-6281-5579
E-mail: hchguo@cau.edu.cn
biologically active compounds containing
a sulfamate
[b] L. Chen
moiety displayed significant biological activities, such as an-
tibiotic, antibacterial, antiviral, antimetastatic, anticonvul-
sant, anticancer, anti-obesity, anti-arthritis, and anti-osteopo-
rosis activity,[6] and thus the sulfamate moiety is often used
as an important pharmacophore in drug design. The devel-
Bee Research Institute
Chinese Academy of Agricultural Sciences
Beijing 100093, China
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201301082.
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Hongchao Guo et al.
Table 2. Substrate scope.[a]
opment of new reactions for the synthesis of the biological
compounds with a sulfamate moiety is highly desirable. In
this context, we carried out the annulation reaction of sulfa-
mate-derived cyclic imines 1 with acetylenedicarboxylates 2.
Unexpectedly, an interesting ring-expansion reaction was
found (Scheme 1c). Herein, we report this new PPh3-cata-
lyzed ring expansion reaction of sulfamate-derived cyclic
imines 1 with acetylenedicarboxylates 2 to give sulfamate-
Entry R1 in 1
R2
t
Product Yield[d] [%]
1
H (1a)
Me (2a) 15 min 3aa
Me (2a) 13 min 3ba
Me (2a) 1 h
Me (2a) 12 min 3da
Me (2a) 25 min 3ea
Me (2a) 25 min 3 fa
Me (2a) 5 min
Me (2a) 1 h
Me (2a) 4 min
Me (2a) 4 min
Me (2a) 5 min
Me (2a) 5 min
Me (2a) 2 h
93
98
80
91
91
95
90
91
92
73
97
92
91
83
86
2
3
4
5
6-Me (1b)
6-OMe (1c)
6-tBu (1d)
6-F (1e)
fused benzo[g]ACHTUNGTRENNUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-di-
oxide derivatives under mild conditions (Scheme 1c).[7]
3ca
6
7
6-Cl (1 f)
6-Br (1g)
7-MeO (1h)
7-Cl (1i)
3ga
3ha
3ia
3ja
3ka
3la
Results and Discussion
8[b]
9
The sulfamate-derived cyclic imines 1[8] were used as the
substrates for phosphine-catalyzed reactions. Initially, we in-
vestigated the cycloaddition of cyclic imine 1a with dimethyl
acetylenedicarboxylate (2a). In the presence of PPh3
(20 mol%), treatment of 1a with 1.2 equiv of 2a in dichloro-
methane at room temperature gave a 61% yield of ring-ex-
pansion product 3aa (Table 1, entry 1), which was identified
10
11[c]
12
13[c]
14[c]
15[c]
7-Br (1j)
8-Me (1k)
8-OMe (1l)
8-tBu (1m)
8-Cl (1n)
8-Br (1o)
3ma
Me (2a) 15 min 3na
Me (2a) 2 h
3oa
16[c]
Me (2a) 9 h
3pa
65
57
Table 1. Ring-expansion reaction of cyclic imine 1a with acetylenedicar-
boxylate 2a.[a]
17[b,c]
Me (2a) 72 h
3qa
18
19
H (1a)
H (1a)
Et (2b)
iPr (2c) 1 h
1 h
3ab
3ac
97
92
[a] 1.2 equiv of acetylenedicarboxylate were used. [b] The reaction was
carried out at 408C. [c] 40 mol% PPh3 was used. [d] Yields of isolated
products.
Entry
Catalyst
Solvent
Yield[b] [%]
1
2
3
4
5
6
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
CH2Cl2
toluene
benzene
THF
AcOEt
acetone
benzene
benzene
benzene
benzene
61
77
93
68
62
55
63
–
but other Lewis bases such as DBU, DABCO, and Et3N
were ineffective (Table 1, entries 8–10).
With PPh3 as catalyst and benzene as solvent, reactions of
various cyclic imines 1 with acetylenedicarboxylates 2 were
evaluated (Table 2). The corresponding ring-expansion prod-
ucts were obtained in 57–98% yield. The results showed
that introducing various substituents, including electron-do-
nating and electron-withdrawing groups, into the 6- or 7-po-
sition of the cyclic imines did not influence the yields of
their reactions with 2a (Table 2, entries 2–10). The reactions
were quite fast and were complete in less than 30 min at
room temperature in most cases. However, 6-MeO-substitut-
ed cyclic imine 1c required a longer time to give the product
3ca in 80% yield (Table 2, entry 3), and 7-MeO-substituted
substrate 1h required elevated temperature and a longer
time to furnish the product 3ha in 91% yield (Table 2,
entry 8). Introducing electron-donating or electron-with-
drawing substituents in the 8-position of the cyclic imines
lowered the activities of the substrates and resulted in
40 mol% of Ph3P being required to promote the reactions
(Table 2, entries 11 and 13–15). Two special substrates (1p
and 1q) required an increased amount of PPh3 (40 mol%)
and longer reaction times, and 1q even required elevated
temperature to promote the reaction, and they provided the
corresponding products in modest yields (Table 2, entries 16
7[c]
8[c]
9[c]
10[c]
DMAP[d]
DBU[e]
DABCO[f]
Et3N
–
–
[a] 1.2 equiv of 2a were used. [b] Yields of isolated products. [c] The reac-
tion time was 72 h. [d] 4-Dimethylaminopyridine. [e] 1,8-Diazabicyclo-
ACHTUNGTRENNUNG[5.4.0]undec-7-ene. [f] 1,4-DiazabicycloACHTUNGTERN[NUGN 2.2.2]octane.
by NMR spectroscopy. A small amount of a more polar
compound was also observed and isolated in less than 5%
yield.[9] Solvent screening indicated that the best-performing
solvent was benzene, and afforded the product 3aa in 93%
yield (Table 1, entry 3). DMAP could also catalyze the reac-
tion to give the product 3aa in 63% yield (Table 1, entry 7),
Abstract in Chinese:
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Hongchao Guo et al.
and 17). Under phosphine-catalysis conditions, diethyl acety-
lenedicarboxylate (2b) and diisopropyl acetylenedicarboxy-
late (2c) could also react with cyclic imine 1a to afford the
corresponding products in 97 and 92% yield, respectively
(Table 2, entries 18 and 19). Under the standard conditions,
0.2 g of cyclic imine 1a was treated with dimethyl acetylene-
dicarboxylate for 6 min to give 3aa in 94% yield of isolated
product. This demonstrated that the reaction could be
a practical method for the synthesis of biologically interest-
ing heterocycles. A byproduct was observed in every case,
and increased in amount over time. Therefore, once sub-
strate conversion is almost complete, the reaction must be
quenched immediately to prevent generation of the byprod-
uct and decreased yield of the major product.
give 4da in 27% yield, although 3da was not fully converted
to 4da. For substrates 1e and 1 f, 29 and 36% yield of the
corresponding compounds 4ea and 4 fa was obtained, re-
spectively (Table 3, entries 6 and 7). The above results
showed that, under phosphine-catalysis conditions, cyclic
imine 1 is more reactive than product 3 toward acetylenedi-
carboxylates.
According to reported mechanistic studies on nucleophilic
phosphine catalyzed reactions and the experimental obser-
vations,[1] a plausible mechanism was proposed for the reac-
tions of the cyclic imines 1 and acetylenedicarboxylate 2a
(Scheme 2). Zwitterion A, formed by conjugate addition of
Next, we studied in detail the byproducts of the above-
mentioned reactions. By using 2D NMR spectroscopy, they
were determined to be benzo[i]ACHTNUTRGNE[UNG 1,2,3]oxathiazecine-4,5,6,7-
tetracarboxylate 2,2-dioxide derivatives 4, formed from two
molecules of acetylenedicarboxylate and a cyclic imine.
Imines 1d–1 f were chosen as substrates to investigate the
generation process of byproducts 4 (Table 3).[10] The reaction
Table 3. Study on the side reaction.[a]
Entry
R in 1
T [8C]/t [min]
3, Yield[b] [%]
4, Yield[b] [%]
1
2
3
4
5
6
7
6-tBu (1d)
6-tBu (1d)
6-tBu (1d)
6-tBu (1d)
6-tBu (1d)
6-F (1e)
25/12
25/15
0/60
0/105
0/120
40/60
25/60
3da, 91
3da, 65
3da, 75
3da, 92
3da, 64
3ea, 70
3 fa, 62
4da, 8
4da, 33
4da, 0
4da, 6
4da, 35
4ea, 29
4 fa, 36
6-Cl (1 f)
Scheme 2. Proposed mechanism for PPh3-catalyzed ring-expansion reac-
tions of cyclic imines with acetylenedicarboxylates.
[a] 1.5 equiv of acetylenedicarboxylate were used. [b] Yields of isolated
products.
PPh3 to acetylenedicarboxylate 2a, undergoes addition to
imines to generate sulfamate B. Intramolecular conjugate
addition of the sulfamate to the phosphonium enoate motif
of intermediate B followed by elimination of PPh3 leads to
[2+2] cycloadduct D and regeneration of PPh3 catalyst.
Ring expansion of intermediate D from a four- to an eight-
membered ring, which would relieve the ring strain and is
of cyclic imine 1d with 1.5 equivalents[11] of acetylenedicar-
boxylate 1a was carried out at room temperature in benzene
with 20 mol% of PPh3. When the reaction was quenched
after 12 and 15 min, compound 4da was isolated in 8 and
33% yield, respectively (Table 3, entries 1 and 2). As the re-
action was too fast at room temperature, it was difficult to
track. To monitor the reaction more easily by TLC, it was
carried out at 08C. After 60 min, about 80% of substrate 1d
was converted, the product 3da was isolated in 75% yield,
but product 4da was not observed (Table 3, entry 3). At the
moment substrate 1d was almost exhausted, compound 4da
appeared. After the reaction proceeded for 120 min, 3da
and 4da were isolated in 64 and 35% yield, respectively
(Table 3, entry 5). Compound 4da was probably formed by
the reaction of 3da with acetylenedicarboxylate 2a. In fact,
under otherwise identical conditions, pure product 3da was
treated with 1.2 equivalents of acetylenedicarboxylate 2a to
enthalpically
favorable,
provides
benzo[g]-
AHCTUNGTRENNUNG
3 as the final product. Once cyclic imine 1 is exhausted,
zwitterion A attacks the carbon–carbon double bond of
product 3 and undergoes conjugate addition to the a,b-unsa-
turated ester to generate intermediate E (pathway a), or
zwitterion A attacks the carbon–nitrogen double bond of
product 3 to give intermediate F (pathway b).[12] Intermedi-
ate E or F then undergoes sequential conjugate addition, ex-
pulsion of the PPh3 catalyst, and ring expansion to give com-
pound 4.
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Hongchao Guo et al.
116.4, 112.3, 56.0, 53.7, 52.9 ppm; HRMS (ESI): m/z calcd for
C14H13NNaO8S+: 378.0254 [M+Na]+; found: 378.0256.
Conclusions
We have developed the phosphine-catalyzed ring-expansion
reaction of sulfamate-derived cyclic imines and acetylenedi-
carboxylates. The reaction is operationally simple, proceeds
smoothly under very mild reaction conditions, and provides
Dimethyl 8-tert-butylbenzo[g]
dioxide (3da)
ACHTUNGTREN[NUNG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
91% yield; white solid; IR (film): n˜max =2961, 1728, 1600, 1558, 1437,
1395, 1261, 1192, 859, 835, 787 cmÀ1 1H NMR (300 MHz, CDCl3): d=
;
7.77 (dd, J=2.4, 8.8 Hz, 1H), 7.35 (d, J=2.4 Hz, 1H), 7.31 (s, 1H), 7.28
(d, J=8.8 Hz, 1H), 3.83 (s, 3H), 3.70 (s, 3H), 1.29 ppm (s, 9H); 13C NMR
(75 MHz, CDCl3): d=173.0, 163.3, 162.3, 151.4, 149.4, 138.3, 134.8, 134.0,
124.7, 118.5, 115.4, 53.6, 52.9, 34.6, 31.0 ppm; HRMS (ESI): m/z calcd for
C17H19NNaO7S+: 404.0774 [M+Na]+; found: 404.0776.
various sulfamate-fused benzo[g]ACTHNUGRTNEUNG[1,2,3]oxathiazocine-4,5-di-
carboxylate 2,2-dioxide derivatives in moderate to excellent
yields. Further efforts to expand the scope of phosphine-cat-
alyzed reactions of sulfamate-derived cyclic imines are un-
derway.
Dimethyl 8-fluorobenzo[g]ACHTGNUTREN[NUNG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ea)
91% yield; white solid; m.p. 158–1608C; IR (film): n˜max =3081, 2960,
Experimental Section
1743, 1723, 1606, 1562, 1480, 1440, 1426, 1392, 1321, 1286, 1251, 1234,
1198, 1171, 1124, 1082, 1014, 1000, 920, 885, 857, 831, 772, 535 cmÀ1
;
General information
1H NMR (300 MHz, CDCl3): d=7.49–7.34 (m, 2H), 7.30 (s, 1H), 7.16–
7.10 (m, 1H), 3.85 (s, 3H), 3.73 ppm (s, 3H); 13C NMR (75 MHz, CDCl3):
d=172.3, 172.2, 163.3, 162.3, 160.6, 157.3, 149.50, 149.47, 138.0, 134.2,
124.6, 124.2, 121.0, 120.9, 116.8, 116.7, 114.6, 114.3, 53.8, 53.1 ppm;
HRMS (ESI): m/z calcd for C13H10FNNaO7S+: 366.0054 [M+Na]+;
found: 366.0056.
All reactions were performed under an air atmosphere in oven-dried
Schlenk tubes with magnetic stirring. Unless otherwise stated, all re-
agents were purchased from commercial suppliers and used without fur-
ther purification. Benzene solvent was used without any purification. IR
spectra were recorded with a Bruker Optics TENSOR 27 instrument. 1H
and 13C NMR spectra were recorded in CDCl3 on a Bruker 300 spectrom-
eter. High-resolution (HR) ESI mass spectra were recorded with an Agi-
lent instrument on samples dissolved in CH3CN.
Dimethyl 8-chlorobenzo[g]ACTHNUGRTNEUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3 fa)
95% yield; white solid; m.p. 171–1738C; IR (film): n˜max =2962, 1721,
General procedure for the ring expansion reactions of cyclic imines (1)
with acetylenedicarboxylates (2)
1598, 1551, 1469, 1436, 1395, 1309, 1277, 1190, 1138,1097, 1081, 1012, 849,
829,804, 768 cmÀ1 1H NMR (300 MHz, CDCl3): d=7.68 (dd, J=2.5,
;
8.8 Hz, 1H), 7.40–7.38 (m, 1H), 7.35–7.31 (m, 1H), 7.30 (s, 1H), 3.86 (s,
3H), 3.74 ppm (s, 3H); 13C NMR (75 MHz, CDCl3): d=172.2, 163.3,
162.3, 151.9, 138.0, 136.9, 134.3, 131.4, 127.8, 120.6, 116.9, 53.9, 53.1 ppm;
HRMS (ESI): m/z calcd for C13H10ClNNaO7S+: 381.9759 [M+Na]+;
found: 381.9760.
Acetylenedicarboxylate 2 (0.30 mmol) and benzene (2 mL) were added
to a solution of the cyclic imine 1 (0.25 mmol), triphenylphosphine
(0.05 mmol), and benzene (4 mL) at room temperature in an oven-dried
15 mL Schlenk tube. The mixture was stirred at room temperature (or
the given temperature) for the given time and then concentrated. The
residue was purified by flash column chromatography (EtOAc/petroleum
ether) to afford the corresponding cycloaddition product.
Dimethyl 8-bromobenzo[g]ACHTUGNTREN[NNUG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ga)
Dimethyl benzo[g]
G
90% yield; white solid; m.p. 178–1808C; IR (film): n˜max =3444, 2961,
(3aa)
1728, 1600, 1558, 1437, 1395, 1261, 1192, 1145, 1081, 1016, 860, 835, 787,
1
737, 624, 585, 556 cmÀ1; H NMR (300 MHz, CDCl3): d=7.82 (dd, J=2.4,
93% yield; white solid; IR (film): n˜max =2958, 1726, 1597, 1552, 1437,
8.8 Hz, 1H), 7.53–7.51 (m, 1H), 7.30 (s, 1H), 7.29–7.24 (m, 1H), 3.86 (s,
3H), 3.74 ppm (s, 3H); 13C NMR (75 MHz, CDCl3): d=172.0, 163.3,
162.3, 152.4, 139.8, 138.0, 134.3, 130.8, 120.8, 118.6, 117.4, 53.9, 53.1 ppm;
HRMS (ESI): m/z calcd for C13H10BrNNaO7S+: 425.9254 [M+Na]+;
found: 425.9238.
1396, 1280, 1252, 1189, 1162, 1130, 1085, 1016, 862, 842, 771, 743,
551 cmÀ1 1H NMR (300 MHz, CDCl3): d=7.78–7.70 (m, 1H), 7.51–7.44
;
(m, 1H), 7.40–7.31 (m, 2H), 7.29 (s, 1H), 3.82 (s, 3H), 3.69 ppm (s, 3H);
13C NMR (75 MHz, CDCl3): d=173.0, 163.2, 162.5, 153.4, 138.3, 137.2,
133.8, 128.6, 126.0, 118.9, 115.9, 53.7, 52.9 ppm; HRMS (ESI): m/z calcd
for C13H11NNaO7S+: 348.0148 [M+Na]+; found: 348.0149.
Dimethyl 9-methoxybenzo[g]ACTHNUGTRNEUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ha)
Dimethyl 8-methylbenzo[g]ACHTGNUTREN[NUNG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
91% yield; white solid; m.p. 121–1228C; IR (film): n˜max =2958, 2923,
dioxide (3ba)
2850, 1725, 1617, 1584, 1534, 1507, 1437, 1382, 1343, 1260, 1189, 1162,
1127, 1083, 1020, 956, 845, 792, 738, 700, 682, 667, 580 cmÀ1 1H NMR
;
98% yield; white solid; m.p. 176–1778C; IR (film): n˜max =2960, 1746,
1718, 1601, 1559, 1482, 1437, 1390, 1317, 1282, 1252, 1209, 1187, 1134,
(300 MHz, CDCl3): d=7.36 (d, J=8.7 Hz, 1H), 7.25 (s, 1H), 6.85–6.78
(m, 2H), 3.93 (s, 3H), 3.82 (s, 3H), 3.70 ppm (s, 3H); 13C NMR (75 MHz,
CDCl3): d=172.0, 166.8, 163.3, 162.8, 156.1, 138.4, 133.6, 130.4, 113.5,
109.5, 103.1, 56.3, 53.6, 52.9 ppm; HRMS (ESI): m/z calcd for
C14H13NNaO8S+: 378.0254 [M+Na]+; found: 378.0253.
1083, 1014, 862, 823, 770, 735, 720, 700, 668, 615, 579, 527 cmÀ1; H NMR
1
(300 MHz, CDCl3): d=7.55–7.49 (m, 1H), 7.29 (s, 1H), 7.24 (d, J=
8.5 Hz, 1H), 7.21–7.17 (m, 1H), 3.83 (s, 3H), 3.71 (s, 3H), 2.38 ppm (s,
3H); 13C NMR (75 MHz, CDCl3): d=173.0, 163.3, 162.7, 151.6, 138.4,
138.1, 136.1, 133.8, 128.2, 118.7, 115.7, 53.7, 52.9, 20.8 ppm; HRMS (ESI):
m/z calcd for C14H13NNaO7S+: 362.0305 [M+Na]+; found: 362.0307.
Dimethyl 9-chlorobenzo[g]ACTHNUGRTNEUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ia)
Dimethyl 8-methoxybenzo[g]ACTHNUGTRNEUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ca)
92% yield; white solid; m.p. 121–1228C; IR (film): n˜max =3093, 2960,
1727, 1595, 1543, 1481, 1438, 1397, 1263, 1193, 1149, 1094, 1073, 1014,
80% yield; white solid; m.p. 130–1318C; IR (film): n˜max =2957, 2924,
2850, 1727, 1620, 1585, 1537, 1507, 1461, 1437, 1390, 1343, 1256, 1217,
1198, 1163, 1132, 1084, 1021, 991, 956, 894, 846, 788, 737, 669, 645, 580,
914, 887, 844, 793, 772, 740, 715, 691, 630, 569, 532 cmÀ1 1H NMR
;
(300 MHz, CDCl3): d=7.42–7.35 (m, 2H), 7.34–7.27 (m, 2H), 3.83 (s,
3H), 3.72 ppm (s, 3H); 13C NMR (75 MHz, CDCl3): d=172.3, 163.2,
162.4, 153.9, 143.3, 138.1, 134.2, 129.5, 126.6, 119.5, 114.6, 53.8, 53.0 ppm;
HRMS (ESI): m/z calcd for C13H10ClNNaO7S+: 381.9759 [M+Na]+;
found: 381.9758.
498 cmÀ1 1H NMR (300 MHz, CDCl3): d=7.29–7.25 (m, 3H), 6.88–6.81
;
(m, 1H), 3.83 (s, 3H), 3.81 (s, 3H), 3.71 ppm (s, 3H); 13C NMR (75 MHz,
CDCl3): d=172.9, 163.3, 162.6, 156.8, 147.2, 138.3, 133.9, 123.0, 120.0,
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Hongchao Guo et al.
Dimethyl 9-bromobenzo[g]
dioxide (3ja)
[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
Dimethyl naphtho
(3pa)
ACHUTGTNREN[UNG 1,2g]CAHTUNGTRENN[UGN 1,2,3]oxathiazocine-2,3-dicarboxylate 5,5-dioxide
73% yield; white solid; m.p. 129–1318C; IR (film): n˜max =3094, 2958,
65% yield; pale yellow solid; m.p. 180–1818C; IR (film): n˜max =3442,
2959, 1725, 1621, 1594, 1582, 1527, 1449, 1437, 1394, 1351, 1260, 1193,
1147, 1121, 1064, 1017, 978, 893, 825, 803, 737, 703, 676, 650, 611, 518,
1725, 1595, 1541, 1478, 1437, 1396, 1263, 1204, 1187, 1148, 1090, 1067,
1015, 989, 901, 844, 793, 770, 743, 626, 566 cmÀ1 1H NMR (300 MHz,
;
CDCl3): d=7.55–7.53 (m, 1H), 7.50–7.45 (m, 1H), 7.31 (d, J=8.4 Hz,
1H), 7.29 (s, 1H), 3.83 (s, 3H), 3.72 ppm (s, 3H); 13C NMR (75 MHz,
CDCl3): d=172.5, 163.2, 162.4, 153.6, 138.1, 134.2, 131.7, 129.5, 129.4,
122.5, 114.9, 53.8, 53.1 ppm; HRMS (ESI): m/z calcd for
C13H10BrNNaO7S+: 425.9254 [M+Na]+; found: 425.9263.
494 cmÀ1 1H NMR (300 MHz, CDCl3): d=8.24–8.13 (m, 2H), 7.98–7.90
;
(m, 1H), 7.68–7.56 (m, 2H), 7.44 (d, J=9.0 Hz, 1H), 7.32 (s, 1H), 3.71 (s,
3H), 3.62 ppm (s, 3H); 13C NMR (75 MHz, CDCl3): d=172.7, 163.8,
162.8, 155.8, 142.4, 139.4, 134.2, 131.1, 130.04, 129.98, 129.2, 126.9, 123.9,
117.5, 112.9, 53.5, 52.9 ppm; HRMS (ESI): m/z calcd for
C17H13NNaO7S+: 398.0305 [M+Na]+; found: 398.0305.
Dimethyl 10-methylbenzo[g]ACHTNUGTREN[NUGN 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ka)
Dimethyl [1,3]dioxolo[4’,5’:4,5]benzoACHTUNGTERNNUG[1,2-g]ACHTUNGTRENN[UGN 1,2,3]oxathiazocine-4,5-
dicarboxylate 2,2-dioxide (3qa)
97% yield; white solid; m.p. 172–1738C; IR (film): n˜max =2958, 2373,
2334, 1725, 1590, 1567, 1438, 1383, 1279, 1224, 1195, 1168, 1129, 1047,
57% yield; pale yellow solid; m.p. 139–1408C; IR (film): n˜max =3439,
1724, 1638, 1527, 1394, 1260, 1193, 1016, 978, 517 cmÀ1 1H NMR
875, 839, 769, 742 cmÀ1
;
1H NMR (300 MHz, CDCl3): d=7.61–7.54 (m,
;
1H), 7.33–7.20 (m, 3H), 3.81 (s, 3H), 3.69 (s, 3H), 2.43 ppm (s, 3H);
13C NMR (75 MHz, CDCl3): d=173.3, 163.3, 162.6, 151.8, 138.7, 138.6,
133.6, 128.8, 126.2, 125.3, 115.7, 53.6, 52.9, 14.7 ppm; HRMS (ESI): m/z
calcd for C14H13NNaO7S+: 362.0305 [M+Na]+; found: 362.0305.
(300 MHz, CDCl3): d=7.24 (s, 1H), 6.80 (s, 1H), 6.75 (s, 1H), 6.14 (s,
2H), 3.83 (s, 3H), 3.73 ppm (s, 3H); 13C NMR (75 MHz, CDCl3): d=
171.9, 163.2, 162.6, 155.0, 151.9, 145.7, 138.5, 133.6, 109.9, 105.6, 103.4,
100.2, 53.7, 52.9 ppm; HRMS (ESI): m/z calcd for C14H11NNaO9S+:
392.0047 [M+Na]+; found: 392.0047.
Dimethyl 10-methoxybenzo[g]ACTHNUTRGNE[NUG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3la)
Dimethyl benzo[g]ACTHUNGTRENN[UNG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-dioxide
(3ab)
92% yield; white solid; m.p. 143–1448C; IR (film): n˜max =2958, 2848,
1726, 1593, 1567, 1479, 1459, 1439, 1394, 1331, 1277, 1228, 1195, 1174,
97% yield; pale yellow solid; m.p. 61–638C; IR (film): n˜max =2986, 1723,
1598, 1553, 1477, 1450, 1397, 1245, 1190, 1161, 1130, 1084, 1028, 977, 862,
771, 618, 551, 515 cmÀ1;1H NMR (300 MHz, CDCl3): d=7.77–7.69 (m,
1H), 7.51–7.45 (m, 1H), 7.38–7.31 (m, 2H), 7.26 (s, 1H), 4.28 (q, J=
7.1 Hz, 2H), 4.13 (q, J=7.1 Hz, 2H), 1.22 (t, J=7.1 Hz, 3H), 1.12 ppm (t,
J=7.1 Hz, 3H); 13C NMR (75 MHz, CDCl3): d=173.2, 162.8, 162.1,
153.4, 138.3, 137.1, 133.9, 128.6, 125.8, 118.9, 116.2, 63.0, 62.3, 13.7,
13.5 ppm; HRMS (ESI): m/z calcd for C15H15NNaO7S+: 376.0461
[M+Na]+; found: 376.0460.
1
1144, 1069, 1014, 902,871, 839, 807, 764, 735, 686, 590, 551 cmÀ1; H NMR
(300 MHz, CDCl3): d=7.32–7.21 (m, 3H), 7.03–6.98 (m, 1H), 3.97 (s,
3H), 3.81 (s, 3H), 3.69 ppm (s, 3H); 13C NMR (75 MHz, CDCl3): d=
173.3, 163.3, 162.6, 148.8, 143.1, 138.5, 133.7, 125.7, 119.31, 119.29, 116.6,
56.6, 53.7, 52.9 ppm; HRMS (ESI): m/z calcd for C14H13NNaO8S+:
378.0254 [M+Na]+; found: 378.0253.
Dimethyl 10-tert-butylbenzo[g]ACTHUNGTREN[NUNG 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3ma)
Dimethyl benzo[g]
(3ac)
ACHTUNGTREN[NUGN 1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-dioxide
91% yield; white solid; m.p. 151–1528C; IR (film): n˜max =2960, 1729,
1607, 1586, 1557, 1436, 1395, 1368, 1258, 1200, 1177, 1105, 1033, 1020,
1
873, 846, 779, 741 cmÀ1; H NMR (300 MHz, CDCl3): d=7.73 (dd, J=2.0,
92% yield; colorless transparent solid; m.p. 73–748C; IR (film): n˜max =
7.5 Hz, 1H), 7.34–7.23 (m, 3H), 3.82 (s, 3H), 3.69 (s, 3H), 1.50 ppm (s,
9H); 13C NMR (75 MHz, CDCl3): d=173.7, 163.3, 162.7, 152.6, 140.7,
138.8, 134.9, 133.6, 126.7, 125.4, 116.7, 53.7, 52.9, 35.1, 29.8 ppm; HRMS
(ESI): m/z calcd for C17H19NNaO7S+: 404.0774 [M+Na]+; found:
404.0772.
2985, 2939, 1717, 1648, 1598, 1554, 1468, 1452, 1399, 1251, 1190, 1147,
1130, 1103, 1083, 1035, 982, 900, 862, 804, 772, 717, 690, 617, 552, 516,
473 cmÀ1 1H NMR (300 MHz, CDCl3): d=7.77–7.69 (m, 1H), 7.48 (dd,
;
J=1.6, 8.1 Hz, 1H), 7.39–7.31 (m, 2H), 7.21 (s, 1H), 5.16–5.06 (m, 1H),
5.01–4.90 (m, 1H), 1.21 (d, J=6.2 Hz, 6H), 1.09 ppm (d, J=6.2 Hz, 6H);
13C NMR (75 MHz, CDCl3): d=173.4, 162.4, 161.8, 153.5, 138.3, 137.1,
134.1, 128.7, 125.8, 118.9, 116.5, 71.3, 70.5, 21.4, 21.2 ppm; HRMS (ESI):
m/z calcd for C17H19NNaO7S+: 404.0774 [M+Na]+; found: 404.0772.
Dimethyl 10-chlorobenzo[g]ACTHNUGTRNEUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3na)
83% yield; white solid; m.p. 170–1728C; IR (film): n˜max =2960, 1723,
1591, 1554, 1438, 1397, 1283, 1257, 1195, 1101, 1019, 802 cmÀ1 1H NMR
Tetramethyl 10-chlorobenzo[i]ACTHNUGTRNEUNG[1,2,3]oxathiazecine-4,5,6,7-tetracarboxylate
2,2-dioxide (4 fa)
;
(300 MHz, CDCl3): d=7.77 (dd, J=1.7, 7.9 Hz, 1H), 7.39–7.34 (m, 1H),
7.32–7.26 (m, 2H), 3.83 (s, 3H), 3.72 ppm (s, 3H); 13C NMR (75 MHz,
CDCl3): d=172.7, 163.3, 162.4, 149.7, 138.3, 137.4, 134.2, 126.8, 125.9,
124.5, 117.3, 53.8, 53.1 ppm; HRMS (ESI): m/z calcd for
C13H10ClNNaO7S+: 381.9759 [M+Na]+; found: 381.9759.
M.p. 155–1568C; IR (film): n˜max =2958, 1730, 1623, 1598, 1554, 1470,
1437, 1400, 1325, 1257, 1192, 1154, 1134, 1105, 1026, 889, 863, 831, 797,
771, 737, 703, 582, 523 cmÀ1 1H NMR (300 MHz, CDCl3): d=7.96 (s,
;
1H), 7.66 (dd, J=2.5, 8.8 Hz, 1H), 7.31 (d, J=8.8 Hz, 1H), 7.08 (s, 1H),
3.90 (s, 3H), 3.83 (s, 3H), 3.70 (s, 3H), 3.67 ppm (s, 3H); 13C NMR
(75 MHz, CDCl3): d=165.4, 163.6, 162.7, 162.3, 151.7, 142.3, 136.4, 133.1,
131.4, 128.8, 120.1, 117.8, 77.2, 53.70, 53.67, 53.3, 52.6 ppm; HRMS (ESI):
m/z calcd for C19H16ClNNaO11S+: 524.0025 [M+Na]+; found: 524.0025.
Dimethyl 10-bromobenzo[g]ACTHNUGRTNEUNG[1,2,3]oxathiazocine-4,5-dicarboxylate 2,2-
dioxide (3oa)
86% yield; white solid; m.p. 168–1698C; IR (film): n˜max =3076, 2960,
1722, 1593, 1549, 1435, 1398, 1374, 1285, 1253, 1194, 1153, 1094, 1016,
866, 843, 809, 791, 771, 735, 683, 584, 553 cmÀ1 1H NMR (300 MHz,
;
CDCl3): d=7.93 (dd, J=1.4, 8.0 Hz, 1H), 7.45–7.39 (m, 1H), 7.30 (s,
1H), 7.24 (t, J=8.0 Hz, 1H), 3.83 (s, 3H), 3.72 ppm (s, 3H); 13C NMR
(75 MHz, CDCl3): d=172.8, 163.3, 162.4, 150.6, 140.5, 138.2, 134.2, 127.6,
126.5, 117.4, 113.0, 53.8, 53.1 ppm; HRMS (ESI): m/z calcd for
C13H10BrNNaO7S+: 425.9254 [M+Na]+; found: 425.9238.
Acknowledgements
This study was supported by the National Natural Science Foundation of
China (No. 21172253), the Program for New Century Excellent Talents in
University (No. NCET-11-0481), the National Scientific and Technology
Supporting Program of China (No. 2011BAE06B05-5), the National S&T
Pillar Program of China (2012BAK25B03), Chinese Universities Scientif-
ic Fund (No. 2013J002 and 2013RC023), and Nutrichem.
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Hongchao Guo et al.
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yield of side product. Moreover, the reaction generated another un-
known side product besides 4.
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[12] To investigate which pathway was followed in the further reaction
of products 3, we performed a cross-reaction of product 3da with di-
ethyl acetylenedicarboxylate (2b). However, a product whose struc-
ture is completely different to that of 4da was obtained. From the
structure of this new product, it can not unambiguously be conclud-
ed through which pathway products 4 were formed. Experimental
details of this reaction and the structure of the new product are
given in the Supporting Information.
Received: August 12, 2013
Revised: September 18, 2013
Published online: November 12, 2013
Chem. Asian J. 2014, 9, 313 – 318
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