DABCO-catalyzed reactions of hydrazones with activated olefins

Article abstract of DOI:10.1016/j.tet.2005.04.071

This paper describes several highly efficient DABCO-catalyzed aza-Michael addition reactions of hydrazones to activated olefins. In most cases, these aza-Michael addition reactions gave the corresponding products in high yields under mild conditions. The plausible reaction mechanism is discussed on the basis of deuterium labeling experiments. Upon treatment with HCl, the corresponding cyclized products can be obtained in high yields from the Michael addition products.

Full text of DOI:10.1016/j.tet.2005.04.071

Tetrahedron 61 (2005) 7277–7288
DABCO-catalyzed reactions of hydrazones with activated olefins
Gui-Ling Zhao and Min Shi
*
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu,
Shanghai 200032, China
Received 10 March 2005; revised 27 April 2005; accepted 30 April 2005
Available online 13 June 2005
Abstract—This paper describes several highly efficient DABCO-catalyzed aza-Michael addition reactions of hydrazones to activated
olefins. In most cases, these aza-Michael addition reactions gave the corresponding products in high yields under mild conditions. The
plausible reaction mechanism is discussed on the basis of deuterium labeling experiments. Upon treatment with HCl, the corresponding
cyclized products can be obtained in high yields from the Michael addition products.
q 2005 Elsevier Ltd. All rights reserved.
1
. Introduction
the Michael addition product 3a in high yields in the
presence of nitrogen containing organic bases such as
DABCO, 4-(N,N-dimethylamino)pyridine (DMAP), 1,8-
Great progress has been made in the execution of the
Morita–Baylis–Hillman reaction, since Baylis and Hillman
1
diazabicyclo[5.4.0]undec-7-ene (DBU) or Et N (10 mol%)
3
first reported the reaction of acetaldehyde with ethyl
acrylate and acrylonitrile in the presence of catalytic
amounts of strong nucleophilic Lewis base such as 1,4-
for 10 h (Table 1, entries 2, 8, 9 and 10). The solvent effects
have been examined using DABCO as a promoter. We
found that tetrahydrofuran (THF) is the solvent of choice. In
the presence of 1.0 mol% of DABCO in THF, the reaction
also proceeded efficiently to give the addition product 3a in
O99% yield after 24 h (Table 1, entry 6). DMAP
(1.0 mol%) and DBU (1.0 mol%) are not as effective as
DABCO (1.0 mol%) under the identical conditions
(Table 1, entries 8 and 9). Triphenylphosphine or tributyl-
2
diazabicyclo[2,2,2]octane (DABCO) in 1972. During our
ongoing investigations on the aza-Baylis–Hillman reactions
of N-tosylated imines (ArCH]NTs) with activated olefins,
we found that either ‘normal’ or ‘abnormal’ reaction
products were formed depending on the employed nucleo-
3
philic Lewis base. In this paper, we wish to report
4
DABCO-catalyzed reactions of hydrazones 1 (R–CH]N–
NHTs, 4-methylbenzenesulfonic acid N-methylidene-
hydrazide) and 2 [R–CH]N–NHC(O)Ph, benzoic acid
N-methylidene-hydrazide] with activated olefins such as
methyl vinyl ketone (MVK), methyl acrylate, acrylonitrile
and phenyl vinyl ketone (PVK) to give the Michael addition
products in good yields. In the present reaction, DABCO
served as a Brønsted base or a proton-sponge rather than a
nucleophilic Lewis base in Baylis–Hillman reaction.
phosphine did not catalyze this reaction (Table 1, entry 7).
It should be noted that using inorganic bases such as K CO ,
2
3
t
KOAc and KOBu in this reaction under the same
conditions, the reaction took place as well, but in low
yields even after a prolonged reaction time, which is
presumably due to their low solubilities in THF.
Under the optimized reaction conditions, we next examined
the reactions of a variety of hydrazones 1 with MVK. The
results are summarized in Table 2. The corresponding
adducts 3 were obtained in good to high yields in the
presence of DABCO (1.0 mol%) (Table 2, entries 1–6). For
aromatic substrates 1b–f, the corresponding adducts 3b–f
were obtained in high yields (Table 2, entries 1–5). When
the benzene ring bears a strongly electron-withdrawing
group such as p-nitrobenzenealdehyde, the reaction
proceeds quickly to give the adduct within shorter reaction
time (Table 1, entry 5). For aliphatic substrate 1g, the
corresponding adduct 3g was obtained in good yield
2
. Results and discussion
As initial examination, a variety of organic bases have been
examined as catalysts in the reaction of hydrazone 1a with
MVK and the results are summarized in Table 1. As can be
seen from Table 1, the reaction proceeded smoothly to give
Keywords: Hydrazones; DABCO; Lewis base; MVK; Methyl acrylate;
Acrylonitrile; Phenyl vinyl ketone.
(
Table 2, entry 6).
*
Corresponding author. Fax: C86 21 64166128;
e-mail: mshi@pub.sioc.ac.cn
Under the same conditions, we further examined the
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.04.071

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G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
Table 1. Reactions of hydrazone 1a (1.0 equiv) with MVK (1.2 equiv) in the presence of organic base catalyst (10 mol%) at room temperature
a
Yield (%) 3a
Entry
Base catalyst
Solvent
Time (h)
1
2
3
4
5
6
7
8
9
—
THF
THF
CH Cl
2 2
MeCN
DMF
THF
THF
THF
THF
THF
10
10
10
10
10
24
10
10
10
10
0
DABCO
DABCO
DABCO
DABCO
DABCO
3 3
PPh or PBu
c
DMAP
O99
91
94
83
O99
0
O99
O99
96
b
d
DBU
Et N
3
10
a
b
c
d
Isolated yields.
DABCO (1.0 mol%) was used.
Using 1.0 mol% of DMAP, 3a was obtained in 82% yield.
Using 1.0 mol% of DBU, 3a was obtained in 80% yield.
Table 2. Reactions of hydrazones 1 (1.0 equiv) with MVK (1.2 equiv) in the presence of DABCO (1.0 mol%) at room temperature
a
Yield (%) 3
Entry
R
Time (h)
1
2
3
4
5
6
p-MeC
p-FC
p-ClC
p-BrC
p-NO
(CH
6
H
H
6 4
4
1b
1c
1d
1e
36
24
24
24
12
24
3b, O99
3c, 89
3d, O99
3e, O99
3f, 84
6
H
4
6 4
H
2
C
6
H
CH 1g
4
1f
3
)
2
3g, 70
a
Isolated yields.
reaction of 1a with other activated olefins such as methyl
acrylate, acrylonitrile, and phenyl vinyl ketone (PVK) and
found that the corresponding adducts 4a, 5a and 6a were
also obtained in good to high yields (Scheme 1).
By a sequential treatment of 1 with MVK in the presence of
DABCO (1.0 mmol) in THF for 24–36 h and then with 5 N
HCl for 2 h, the cyclized product 7 was also obtained in
good yields. The results are summarized in Table 3.
It should be emphasized here that treatment of 3a or 6a with
5 N HCl for 2 h gave the cyclized product 7 or 8 in high
yield at room temperature (Scheme 2).
We next examined the reactions of hydrazone 2a having a
N-benzoyl protecting group with MVK in a variety of
solvents in the presence of various organic base catalysts to
Scheme 1. Reactions of hydrazone 1a (1.0 equiv) with other activated olefins (1.2 equiv) in the presence of DABCO (1 mol%) in THF.

G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
7279
Scheme 2. Cyclization of 3a or 6a with 5 N HCl.
Table 3. Reactions of hydrazones 1 (1.0 equiv) with MVK (1.2 equiv) in the presence of DABCO (1 mol%) and then with 5 N HCl
a
Yield (%) of 7 (two steps)
Entry
R
Time (h)
1
2
3
4
5
6
C
6
H
5
1a
24, 2
36, 2
24, 2
24, 2
24, 2
24, 2
O99
89
78
O99
95
92
p-MeC
p-FC
p-ClC
p-BrC
(CH
6
H
4
1b
6
H
4
1c
6
H
4
1d
1e
6 4
H
3
)
2
CH 1g
a
Isolated yields.
optimize the reaction conditions. The result are shown in
Table 4 (entries 1–9). We were pleased to find that using
hydrazone 2a as a substrate and DABCO (10 mol%) as the
base catalyst in N,N-dimethylformamide (DMF), the
Michael addition product 9a can be obtained in 91% yield
after a prolonged reaction time (Table 4, entry 6). The
results of hydrazones 2b and 2c combined with 2a under the
optimized reaction conditions are summarized in Table 5.
For aliphatic hydrazone 2c, the corresponding Michael
addition product 9c was formed in 56% yield (Table 5, entry
3).
Accordingly, treatment of 2a with MVK in the presence of
DABCO in DMF for 96 h and then with 5 N HCl for 12 h,
the corresponding cyclized product 10 was obtained in 98%
yield (Scheme 3).
Table 4. Reactions of hydrazone 2a (1.0 equiv) with MVK (1.2 equiv) in the presence of nitrogen containing organic base (10 mol%) at room temperature
a
Yield (%) of 9a
Entry
Organic base
Solvent
Time (h)
1
2
3
4
5
6
7
8
9
DABCO
DABCO
DABCO
DABCO
DABCO
DABCO
DMAP
THF
DME
96
96
96
96
96
96
96
96
96
0
0
0
b
EtOH
CH CN
3
Trace
Trace
91
71
68
CH COCH
3
3
DMF
DMF
DMF
DMF
DBU
Et
3
N
Trace
a
Isolated yields.
The reaction was carried under reflux.
b

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G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
Table 5. Reactions of hydrazones 2 (1.0 equiv) with MVK (1.2 equiv) in the presence of DABCO (10 mol%) at room temperature
a
Yield (%) of 9
Entry
R
Time (h)
1
2
3
C
6
H
5
2a
2b
CH 2c
96
72
96
9a, 91
9b, 90
9c, 56
p-ClC
3 2
(CH )
6
H
4
a
Isolated yields.
Scheme 3. Reaction of hydrazone 2a (1.0 equiv) with MVK (1.2 equiv) in the presence of DABCO (10 mol%) at room temperature and then with 5 N HCl.
Table 6. Reactions of aryladehyde (1.0 equiv) with phenyl hydrazine and MVK (1.2 equiv) in the presence of DABCO (10 mol%)
a
Yield (%) of 11 (two steps)
Entry
Ar
1
2
3
C
p-CH
p-ClC
6
H
C H
3 6 4
H
6 4
5
11a, 34
11b, 20
11c, 39
a
Isolated yields.
and MVK (Scheme 6) produced trace of cyclized product 7,
and no aza-Michael addition product 3 were obtained. These
results suggest that the acidity of N–H proton in hydrazones
1
and 2 plays a significant role in this DABCO-catalyzed
reaction. The N-tosylated or N-acylated hydrazones 1 and 2
can react with MVK and other activated olefins in the
presence of DABCO to give the corresponding Michael
addition products in good yields. This synthetic method can
Scheme 4. Cyclization of 11a with 5 N HCl.
0
phenylhydrazine (Ar–CH]N–NH–Ph) prepared in situ
Next, we examined the reactions of N-arylmethylidene-N -
5
with MVK under the similar conditions. The results are
summarized in Table 6. The Michael addition adducts 11
could be obtained, but in lower yields. Cyclization of 11a
could also take place upon treating with 5 N HCl to give the
cyclized product 12 in 31% yield (Scheme 4).
In order to clarify the scope and limitation of this interesting
DABCO-catalyzed aza-Michael addition reaction, the
reactions of TsNH2, TsNHNH , or PhNHNH with
6
7
2
2
MVK were carried out under the similar conditions in the
presence of DABCO (10 mol%) (Scheme 5). However, we
found that all these reactions were sluggish and the
corresponding adducts were obtained in trace to only low
yields even after a prolonged reaction time. Attempts to
perform the one-pot reaction of aldehydes, tosylhydrazine,
Scheme 5. Reactions of TsNH
MVK (1.2 equiv) in the presence of DABCO (10 mol%).
2 2 2
, TsNHNH PhNHNH (1.0 equiv) with

G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
7281
Scheme 6. The one-pot reaction of PhCHO (1.0 equiv), TsNHNH
2
(1.0 equiv) with MVK (1.2 equiv) in the presence of DABCO (10 mol%).
produce pyrazoline derivatives in high yields comparing to
8
previously reported methods.
Schemes 7 and 8), one plausible explanation is proposed
in Scheme 9.
The mechanism of this interesting organic nitrogen
base promoted reaction has not been unequivocally
established, but on the basis of previous investigations
and our deuterium labeling experiments (Figs. 1–8,
We first carried out the following deuterium labeling
experiment to clarify this mechanism. In the presence of
DABCO (0.1 mmol), we found that the H/D exchange of 3-
1
,9,10
pentanone (0.1 mmol) took place rapidly in D O (0.5 mL)
2
1
Figure 1. The H NMR spectrum of 3-pentanone in D
2
O.
1
Figure 2. The H NMR spectrum of 3-pentanone (0.1 mmol) and DABCO (0.1 mmol) in D
2
O.

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G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
1
6 6
Figure 3. The H NMR spectrum of hydrazone 1a in C D .
1
Figure 4. The H NMR spectrum of hydrazone 1a with D
2
O in C
6
D
6
.
1
Figure 5. The H NMR spectrum of hydrazone 1a in C
6
D
6
.

G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
7283
1
6 6
Figure 6. The H NMR spectrum of hydrazone 1a (0.05 mmol) with DABCO (0.05 mmol) in C D .
1
(
Scheme 7), which could be clearly observed from H NMR
spectra shown in Figures 1 and 2. The methylene protons at
.53 ppm (q) in Figure 1 completely disappeared in Figure 2
proton of 1a disappeared and a new signal appeared at
5.95 ppm which can be supposed to be [DABCOH] (the
signal at d 2.43 ppm (s) is DABCO). Thus, we believe that
DABCO functions as a base to abstract the N–H proton in 1a
directly.
C
2
and the signal at d 2.70 ppm (s) in Figure 2 was DABCO.
The deuterium labeling experiment of hydrazone 1a
(
0.05 mmol) with DABCO (0.05 mmol) in C D (0.5 mL)
6
Moreover, the following deuterium labeling experiment was
also performed (Scheme 8). The deuterium labeled
nucleophilic reagent 1a-d was prepared with DCl in D O
6
1
was also examined. Their H NMR spectra were shown in
Figures 3–6. From Figures 3, 4 and 5, we can assign the
2
1
exact chemical shift of NH and CH in the H NMR spectrum
according to Scheme 8, which was used in the DABCO-
catalyzed aza-Michael addition reaction with MVK under
the similar conditions as those described above. The
deuterium incorporated Michael addition product 3a-d
of 1a because the signal at d 7.97 ppm completely
disappeared with the addition of deuterium oxide (D O) in
2
C D . Their chemical shifts have been clearly shown in
6
6
1
Figure 5 (dNH at 7.97 ppm and dCH at 6.93 ppm).
was obtained in 89% yield (D content 94%). The H and
3
C NMR spectra of 3a-d are given in Figures 7 and 8.
1
1
Next, we examined the H NMR spectrum of 1a in C D
6
6
with the addition of DABCO. This spectroscopic chart is
shown in Figure 6. From Figure 6, we observed that the N–H
Overall, on the basis of the above spectroscopic investi-
gations, we believe that DABCO acts as a Brønsted base
1
Figure 7. The H NMR spectrum of 3a-d in CDCl
3
.

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G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
13
3
Figure 8. The C NMR spectrum of 3a-d in CDCl .
catalytic cycle (Scheme 9). The N–H proton of N-sulfonated
group has higher acidity because SO R is a strongly
2
electron-withdrawing group. Therefore, its proton can be
easily removed by DABCO. This is why the reaction rate of
1
is remarkably higher than that of 2 and only 1.0 mol% of
Scheme 7. DABCO-catalyzed H/D exchange of 3-pentanone in D
2
O.
DABCO is enough to accomplish this catalytic reaction
under otherwise identical conditions.
Scheme 8. The reaction of deuterium labeled 1a (1.0 equiv) with MVK (1.2 equiv) in the presence of DABCO (10 mol%).
which abstracts a proton from hydrazone 1 or 2 to produce
nucleophilic intermediate A. The subsequent conjugate
addition of A to MVK generates enolate B. Reprotonation of
enolate B affords 3 and regenerates DABCO to complete the
3. Conclusion
We disclosed an interesting organic nitrogen base DABCO
promoted aza-Michael addition reaction of 1 or 2 with
Scheme 9. Proposed reaction mechanism of DABCO catalyzed reaction of hydrazone 1 or 2 with activated olefins.

G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
7285
C1
C
activated olefins. The transformation is in contrast to the
recently reported DABCO catalyzed aza-Baylis–Hillman
reaction and the reaction mechanism is different from
HRMS (MALDI) calcd for C H N O SNa (M C Na):
18 20 2 3
367.1087. Found: 367.1074.
3
0
phosphine Lewis base catalyzed Michael addition of
4.2.2. 4-Methylbenzenesulfonic acid N -(4-methylbenzyl-
idene)-N-(3-oxobutyl) hydrazide 3b. Colorless solid; mp
102–105 8C (recrystallized from dichloromethane and
petroleum ether); IR (CH Cl ) n 3463, 3055, 1690,
(C]O), 1357, 1170, 896 cm H NMR (CDCl3,
300 MHz, TMS) d 2.16 (3H, s, CH ), 2.39 (3H, s, CH ),
1
1
alcohols to activated olefins. Additionally, this finding
can open new ways for the design of new reactions and
synthesis of novel compounds by the organocatalysts in the
future. The scope and limitations of this reaction have been
disclosed along with the detailed investigation on the
plausible reaction mechanism. Efforts are underway to
elucidate the mechanistic details of this reaction and to
extend the scope of those reactions in other C–C bond
forming transformations thereof.
2
2
K1
1
;
3
3
2.42 (3H, s, CH ), 2.76 (2H, t, JZ7.2 Hz, CH ), 3.74 (2H, t,
3
2
JZ7.2 Hz, CH ), 7.21 (2H, d, JZ7.8 Hz, ArH), 7.31 (2H, d,
JZ7.8 Hz, ArH), 7.56 (2H, d, JZ7.8 Hz, ArH), 7.71 (2H, d,
JZ7.8 Hz, ArH), 8.16 (1H, s, CH); C NMR (CDCl3,
2
1
3
75 MHz, TMS) d 21.5, 21.5, 30.2, 41.8, 44.5, 127.9, 128.3,
129.4, 129.5, 130.7, 133.3, 141.3, 144.1, 154.9, 206.3; MS
(EI) m/z 358 (M , 5.19), 203 (M K155, 22.71), 161
C
C
4
. Experimental
C
M K197, 20.25), 145 (M K213, 77.31), 133 (M K
C
C
(
C1
4
.1. General remarks
225, 100); HRMS (MALDI) calcd for C H N O SNa
19 22 2 3
C
M C Na): 381.1243. Found: 381.1251.
(
MPs were obtained with a Yanagimoto micro melting point
apparatus and are uncorrected. H NMR spectra were
1
0
4.2.3. 4-Methylbenzenesulfonic acid N -(4-fluorobenzyl-
idene)-N-(3-oxobutyl) hydrazide 3c. Colorless oil; IR
(CH Cl ) n 3512, 3251, 1714 (C]O), 1644, 1357, 1233,
recorded on a Bruker AM-300 spectrometer for solution in
CDCl with tetramethylsilane (TMS) as internal standard;
3
2
2
K1 1
J-values are in Hz. Mass spectra were recorded with a HP-
5
837 cm ; H NMR (CDCl , 300 MHz, TMS) d 2.17 (3H, s,
3
CH ), 2.42 (3H, s, CH ), 2.78 (2H, t, JZ7.2 Hz, CH ), 3.78
989 instrument. All of the solid compounds reported in this
3
3
2
paper gave satisfactory CHN microanalyses with a Carlo-
Erba 1106 analyzer. Commercially obtained reagents were
used without further purification. All reactions were
monitored by TLC with Huanghai GF254 silica gel coated
plates. Flash column chromatography was carried out using
200–300 mesh silica gel at medium pressure. The starting
materials hydrazones 1 and 2 were prepared according to the
literature.
(2H, t, JZ7.2 Hz, CH ), 7.06–7.12 (2H, m, ArH), 7.31 (2H,
2
d, JZ8.1 Hz, ArH), 7.63–7.68 (2H, m, ArH), 7.72 (2H, d,
1
3
JZ8.1 Hz, ArH), 8.10 (1H, s, CH); C NMR (CDCl3,
75 MHz, TMS) d 21.3, 30.0, 41.4, 43.8, 115.6 (d, JZ
21.8 Hz), 128.0, 129.4, 129.5 (d, JZ8.0 Hz), 129.7 (d, JZ
2.9 Hz), 133.3, 144.1, 150.8, 163.9 (d, JZ250.1 Hz), 206.1;
C
C
MS (EI) m/z 362 (M , 7.08), 207 (M K155, 57.49), 165
(M K197, 65.52), 149 (M K213, 30.54), 137 (M K
C
C
C
C
25, 100), 108 (M K254, 57.31); HRMS (MALDI) calcd
2
C1
C
(M C Na): 385.0993. Found:
4.2. Typical reaction procedure for the nitrogen Lewis
base-catalyzed reaction of 4-methylbenzenesulfonic acid
for C18
H
19
N
2
O
3
FSNa
385.1012.
N-methylidene-hydrazide 1a with methyl vinyl ketone
(
0
MVK)
4.2.4. 4-Methylbenzenesulfonic acid N -(4-chlorobenzyl-
idene)-N-(3-oxobutyl) hydrazide 3d. Colorless solid; mp
78–80 8C (recrystallized from dichloromethane and
petroleum ether); IR (CH Cl ) n 2922, 1701 (C]O),
To a Schlenk tube with 1a (274 mg, 1.0 mmol) and DABCO
1.0 mg, 0.01 mmol) in THF (1.0 mL) was added methyl
vinyl ketone (MVK) (70 mg, 83 mL, 1.0 mmol) under an
(
2
2
K1
1
1677, 1597, 1492, 1355, 1167, 1093 cm
(CDCl , 300 MHz, TMS) d 2.17 (3H, s, CH ), 2.41 (3H, s,
CH ), 2.80 (2H, t, JZ6.9 Hz, CH ), 3.84 (2H, t, JZ6.9 Hz,
3 2
;
H NMR
argon atmosphere and the reaction mixture was stirred for
4 h at room temperature (20 8C). The reaction mixture was
3
3
2
diluted with dichloromethane (20 mL). The solvent was
removed under reduced pressure and the residue was
purified by silica gel column chromatography (eluent:
EtOAc/petroleumZ1/2) to give 3a (341 mg, 99%) as a
colorless solid.
CH ), 7.31 (2H, d, JZ8.1 Hz, ArH), 7.36 (2H, d, JZ8.1 Hz,
2
ArH), 7.59 (2H, d, JZ8.1 Hz, ArH), 7.73 (2H, d, JZ8.1 Hz,
1
ArH), 8.00 (1H, s, CH); C NMR (CDCl , 75 MHz, TMS) d
3
3
21.4, 30.1, 41.5, 43.4, 128.0, 128.7, 128.8, 129.5, 132.1,
133.5, 136.2, 144.2, 148.9, 206.1; MS (EI) m/z 378 (M ,
C
C C
.55), 223 (M K155, 27.43), 181 (M K197, 33.44), 165
4
(M K213, 30.54), 153 (M K225, 52.04), 43 (M K335,
0
3-oxobutyl)hydrazide 3a. Colorless solid; mp 55–58 8C
C
C
C
4
(
.2.1. 4-Methylbenzenesulfonic acid N -benzylidene-N-
C1
100); HRMS (MALDI) calcd for C18H N O SCl
20 2 3
C
(M CH): 379.0878. Found: 379.0887.
(
IR (CH Cl ) n 3296, 3062, 1716 (C]O), 1676, 1358,
recrystallized from dichloromethane and petroleum ether);
2
2
K1
090 cm ; H NMR (CDCl , 300 MHz, TMS) d 2.16 (3H,
1
0
1
4.2.5. 4-Methylbenzenesulfonic acid N -(4-bromobenzyl-
idene)-N-(3-oxobutyl) hydrazide 3e. Colorless solid; mp
105–108 8C (recrystallized from dichloromethane and
petroleum ether); IR (CH Cl ) n 3052, 2927, 1699
3
s, CH ), 2.41 (3H, s, CH ), 2.79 (2H, t, JZ7.2 Hz, CH ),
3
3
2
3
.82 (2H, t, JZ7.2 Hz, CH ), 7.31 (2H, d, JZ8.4 Hz, ArH),
2
7
.39–7.41 (3H, m, ArH), 7.64–7.68 (2H, m, ArH), 7.74 (2H,
2
2
1
3
K1 1
d, JZ8.4 Hz, ArH), 8.10 (1H, s, CH); C NMR (CDCl3,
(C]O), 1674, 1356, 1093, 818 cm ; H NMR (CDCl ,
3
7
1
3
5
5 MHz, TMS) d 21.5, 30.2, 41.6, 43.9, 127.7, 128.2, 128.6,
29.3, 129.5, 130.6, 133.5, 144.2, 152.5, 206.3; MS (EI) m/z
300 MHz, TMS) d 2.17 (3H, s, CH ), 2.41 (3H, s, CH ), 2.80
3
3
(2H, t, JZ7.2 Hz, CH ), 3.84 (2H, t, JZ7.2 Hz, CH ), 7.31
2
2
C
44 (M , 6.54), 189 (M K155, 47.72), 147 (M K197,
C
C
(2H, d, JZ8.1 Hz, ArH), 7.51 (4H, s, ArH), 7.73 (2H, d, JZ
C C
2.01), 131 (M K213, 73.05), 119 (M K225, 100);
13
8.1 Hz, ArH), 7.97 (1H, s, CH); C NMR (CDCl , 75 MHz,
3

7286
G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
C1
TMS) d 21.4, 30.1, 41.3, 43.2, 124.5, 127.9, 128.8, 129.4,
31.7, 132.5, 133.5, 144.2, 148.2, 206.1; MS (EI) m/z 424
243, 100); HRMS (MALDI) calcd for C H N O S
17 18 3 2
C
(M CH): 328.1114. Found: 328.1121.
1
C
M C2, 9.57), 422 (M , 9.34), 269 (M K153, 46.51),
C
C
(
2
C C
67 (M K155, 48.85), 199 (M K123, 77.35), 197
0
4.2.10. 4-Methylbenzenesulfonic acid N -benzylidene-N-
(3-oxo-3-phenyl-propyl)hydrazide 6a. A yellow oil; IR
(CH Cl ) n 3059, 1691 (C]O), 1597, 1449, 1356, 1266,
169 cm ; H NMR (CDCl , 300 MHz, TMS) d 2.43 (3H,
3
s, CH ), 3.35 (2H, t, JZ7.2 Hz, CH ), 4.06 (2H, t, JZ
C C
M K125, 81.39), 89 (M K333, 100); HRMS (MALDI)
(
calcd for C H N O SBr : 422.0294. Found: 422.0290.
C1
1
8
19
2
3
2
2
K1
1
1
0
4
.2.6. 4-Methylbenzenesulfonic acid N -(4-nitrobenzyl-
idene)-N-(3-oxobutyl) hydrazide 3f. Colorless solid; mp
55–157 8C (recrystallized from dichloromethane and
petroleum ether); IR (CH Cl ) n 3449, 1713 (C]O),
3
2
7.2 Hz, CH ), 7.33 (2H, d, JZ7.8 Hz, ArH), 7.40–7.49 (5H,
2
1
m, ArH), 7.56–7.58 (1H, m, ArH), 7.66–7.69 (2H, m, ArH),
7.76 (2H, d, JZ8.4 Hz, ArH), 7.92–7.95 (2H, m, ArH), 8.12
2
K1
2
1
13
(1H, s, CH); C NMR (CDCl , 75 MHz, TMS) d 21.3, 36.7,
1639, 1343, 1166, 851 cm ; H NMR (CDCl , 300 MHz,
TMS) d 2.21 (3H, s, CH ), 2.43 (3H, s, CH ), 2.90 (2H, t,
3
3
44.1, 127.5, 127.8, 128.0, 128.4, 128.5, 129.4, 130.4, 133.3,
133.5, 133.7, 136.0, 144.0, 150.8, 197.4; MS (EI) m/z 406
3
3
JZ6.9 Hz, CH ), 4.00 (2H, t, JZ6.9 Hz, CH ), 7.34 (2H, d,
2
2
C
C
(M , 0.09), 300 (M K106, 23.02), 159 (M K247,
C
JZ7.8 Hz, ArH), 7.76–7.86 (5H, m, ArH, CH), 8.24 (2H, d,
1
3
C C
36.20), 145 (M K261, 89.02), 105 (M K301, 100), 77
JZ9.0 Hz, ArH); C NMR (CDCl , 75 MHz, TMS) d 21.5,
3
C
(M K329, 96.97); HRMS (MALDI) calcd for
3
1
2
2
0.3, 41.3, 42.2, 123.9, 127.7, 128.0, 129.7, 134.0, 139.9,
C
41.4, 144.6, 148.2, 206.1; MS (EI) m/z 389 (M , 4.35),
C1
C
C H N O S (M CH): 407.1424. Found: 407.1408.
23 23 2 3
C
C
C
34 (M K155, 100), 192 (M K197, 86.00), 91 (M K
C
98, 43.70), 43 (M K346, 84.65); HRMS (MALDI) calcd
4.3. Typical reaction procedure for the one-pot reaction
of 4-methylbenzenesulfonic acid N-methylidene-
hydrazide 1a with methyl vinyl ketone (MVK)
C1
for C H N O SNa : 412.0938. Found: 412.0939.
18 19 3 5
0
3-oxobutyl)hydrazide 3g. Colorless oil; IR (CH Cl ) n
4
(
.2.7. 4-Methylbenzenesulfonic acid N -isobutylidene-N-
To a Schlenk tube with 1a (274 mg, 1.0 mmol) and DABCO
(1.0 mg, 0.01 mmol) in THF (1.0 mL) was added methyl
vinyl ketone (MVK) (70 mg, 83 mL, 1.0 mmol) under an
argon atmosphere and the reaction mixture was stirred for
24 h at room temperature (20 8C). Then 5 N HCl (2 mL) was
added and the reaction mixture was stirred for another 2 h at
room temperature. Then the reaction mixture was extracted
with dichloromethane (2!20 mL). The organic layer was
dried over anhydrous Na SO , the solvent was removed
2
2
3
8
426, 2971, 2877, 1717 (C]O), 1597, 1434, 1352,
16 cm ; H NMR (CDCl , 300 MHz, TMS) d 1.09 (3H,
K1
1
3
s, CH ), 1.11 (3H, s, CH ), 2.14 (3H, s, CH ), 2.41 (3H, s,
3
3
3
CH ), 2.53–2.59 (1H, m, CH), 2.63 (2H, t, JZ7.2 Hz, CH ),
3
2
3
.51 (2H, t, JZ7.2 Hz, CH ), 7.29–7.31 (2H, m, ArH),
2
13
7
.61–7.66 (3H, m, ArH, CH); C NMR (CDCl , 75 MHz,
3
TMS) d 19.1, 21.4, 29.9, 31.9, 41.7, 44.9, 128.3, 129.2,
1
C
32.7, 144.0, 168.2, 206.2; MS (EI) m/z 310 (M , 0.25),
2
4
C
55 (M K155, 49.89), 113 (M K197, 23.72), 91 (M K
C
C
1
under reduced pressure and the residue purified by silica gel
column chromatography (eluent: EtOAc/petroleumZ1/1)
to give 7 (236 mg, 99%) as a white solid.
C
19, 36.09), 43 (M K267, 100); HRMS (MALDI) calcd
2
for C H N O S
C1
C
(M CH): 311.1424. Found:
1
5
23
2
3
3
11.1432.
4
.3.1. 3-Methyl-1-(toluene-4-sulfonyl)-4,5-dihydro-1H-
0
4
.2.8. 3-(N-(4-Methylbenzenesulfonyl)-N -benzylidene-
pyrazole 7. Mp O300 8C (recrystallized from dichloro-
methane and petroleum ether); IR (CH Cl ) n 3434, 1712
(C]O), 1633, 1348, 988 cm
300 MHz, TMS) d 1.96 (3H, s, CH ), 2.43 (3H, s, CH ),
hydrazino)-propionic acid methyl ester 4a. Colorless
oil; IR (CH Cl ) n 2953, 1743 (C]O), 1598, 1439, 1352,
2
2
K1
1
;
H NMR (CDCl3,
2
2
K1
162, 1090 cm ; H NMR (CDCl , 300 MHz, TMS) d
1
1
3
3
3
2
.42 (3H, s, CH ), 2.63 (2H, t, JZ7.2 Hz, CH ), 3.67 (3H, s,
2.65 (2H, t, JZ9.6 Hz, CH ), 3.50 (2H, t, JZ9.6 Hz, CH ),
2 2
3
2
OCH ), 3.83 (2H, t, JZ7.2 Hz, CH ), 7.31 (2H, d, JZ
7.32 (2H, d, JZ8.4 Hz, ArH), 7.76 (2H, d, JZ8.4 Hz, ArH);
3
2
1
3
8
.4 Hz, ArH), 7.39–7.43 (3H, m, ArH), 7.66–7.69 (2H, m,
C NMR (CDCl , 75 MHz, TMS) d 15.9, 21.5, 36. 7, 47.9,
3
1
3
C
128.7, 129.3, 130.8, 144.1, 160.0; MS (EI) m/z 238 (M ,
ArH), 7.74 (2H, d, JZ8.4 Hz, ArH), 8.19 (1H, s, CH); C
NMR (CDCl , 75 MHz, TMS) d 21.1, 32.3, 44.5, 51.4,
C C
47.54), 155 (M K83, 30.26), 139 (M K99, 23.99), 91
3
C C
(M K147, 100), 83 (M K155, 42.70). Anal. Calcd for
1
1
4
27.4, 127.9, 128.3, 129.2, 130.4, 133.2, 133.3, 143.9,
C C
52.6, 170.9; MS (EI) m/z 360 (M , 9.73), 205 (M K155,
C H N O S requires C, 55.44; H, 5.92; N, 11.76%.
1
1 14 2 2
C C
0.85), 173 (M K187, 57.13), 131 (M K229, 100); 90
Found: C, 55.27; H, 5.87; N, 11.63%.
C
(M K270, 90.78); HRMS (MALDI) calcd for
C H N O S (M CH): 361.1217. Found: 361.1239.
C1
C
1
8 21 2 4
4.3.2. 3-Phenyl-1-(toluene-4-sulfonyl)-4,5-dihydro-1H-
pyrazole 8. A yellow oil; IR (CH Cl ) n 3055, 2986,
1356, 1266, 1171, 739 cm ; H NMR (CDCl , 300 MHz,
2
2
0
2-cyano-ethyl)-hydrazide 5a. A yellow oil; IR (CH Cl ) n
K1 1
4
.2.9. 4-Methylbenzenesulfonic acid N -benzylidene-N-
3
(
TMS) d 2.60 (3H, s, CH ), 3.28 (2H, t, JZ9.6 Hz, CH ),
2
2
3
2
K1
1
060, 2923, 2850, 1598, 1356, 1266, 1168 cm ; H NMR
3
3.88 (2H, t, JZ9.6 Hz, CH ), 7.48 (2H, d, JZ7.2 Hz, ArH),
2
(
CDCl , 300 MHz, TMS) d 2.38 (3H, s, CH ), 2.57 (2H, t,
3
7.58–7.61 (3H, m, ArH), 7.87–7.90 (2H, m, ArH), 8.03 (2H,
3
1
3
JZ6.9 Hz, CH ), 3.61 (2H, t, JZ6.9 Hz, CH ), 7.27 (2H, d,
d, JZ7.2 Hz, ArH); C NMR (CDCl , 75 MHz, TMS) d
2
2
3
JZ8.4 Hz, ArH), 7.37–7.41 (3H, m, ArH), 7.59 (2H, d, JZ
21.5, 32.7, 48.6, 126.8, 128.5, 128.7, 129.4, 130.4, 130.7,
130.9, 144.3, 158.3; MS (EI) m/z 300 (M , 24.11), 219
C
8
.4 Hz, ArH), 7.63–7.65 (2H, m, ArH), 8.46 (1H, s, CH);
C NMR (CDCl , 75 MHz, TMS) d 17.5, 21.6, 46.5, 117.1,
1
3
C
C
C
(M K81, 14.13), 197 (M K103, 38.18), 145 (M K155,
3
C
100), 91 (M K209, 75.80). Anal. Calcd for C H N O S
1
1
1
28.4, 128.5, 128.9, 129.8, 131.8, 132.7, 132.9, 144.8,
61.5; MS (EI) m/z 327 (M , 0.92), 222 (M K105, 2.25),
1
6 16 2 2
C
C
requires C, 63.98; H, 5.37; N, 9.33%. Found: C, 63.95; H,
5.30; N, 9.28%.
C
C
72 (M K155, 4.47), 119 (M K208, 26.08), 84 (M K
C

G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
7287
0
4
.3.3. Benzoic acid N -benzylidene-N-(3-oxobutyl)hydra-
6.97 (1H, m, ArH), 7.24–7.40 (7H, m, ArH), 7.50 (1H, s,
CH), 7.67–7.70 (2H, m, ArH); C NMR (CDCl , 75 MHz,
1
3
zide 9a. Colorless solid; mp 107–110 8C (recrystallized
from dichloromethane and petroleum ether); IR (CH Cl ) n
3
TMS) d 30.46, 38.15, 39.31, 115.03, 120.79, 126.00, 127.83,
128.50, 129.13, 131.65, 136.35, 146.42, 206.88; MS (EI)
2
2
K1 1
441, 1713 (C]O), 1608, 1414, 1340, 694 cm ; H NMR
3
(
C
m/z 266 (M , 39.39), 209 (M K57, 38.54), 119 (M K
C
C
CDCl , 300 MHz, TMS) d 2.24 (3H, s, CH ), 2.89 (2H, t,
3
JZ7.5 Hz, CH ), 4.43 (2H, t, JZ7.5 Hz, CH ), 7.32–7.35
3
C C
147, 41.73), 106 (M K160, 81.61), 77 (M K189, 100);
2
2
(
3H, m, ArH), 7.43–7.50 (5H, m, ArH), 7.71–7.74 (2H, m,
ArH), 7.82 (1H, s, CH); C NMR (CDCl , 75 MHz, TMS) d
HRMS (MALDI) calcd for C H N O: 266.1419. Found:
1
266.1413.
7 18 2
1
3
3
3
1
3
0.2, 35.8, 39.2, 127.1, 127.2, 128.6, 129.6, 129.8, 130.3,
34.4, 134.8, 142.5, 170.9, 206.5; MS (EI) m/z 294 (M ,
C
4.3.8. 4-[N-(4-Methylbenzylidene)-N-phenylhydrazino]-
butan-2-one 11b. A yellow oil; IR (CH Cl ) n 3002, 2921,
C C
.13), 188 (M K106, 6.52), 148 (M K146, 17.03), 105
2
2
C
C
K1
1
(M K189, 100), 77 (M K217, 37.85). Anal. Calcd for
C H N O requires C, 73.45; H, 6.16; N, 9.52%. Found:
C, 73.40; H, 6.26; N, 9.35%.
1712 (C]O), 1592, 1498, 1363, 1221, 1143 cm ; H
NMR (CDCl , 300 MHz, TMS) d 2.19 (3H, s, CH ), 2.36
1
8
18
2
2
3
3
(3H, s, CH ), 2.80 (2H, t, JZ7.5 Hz, CH ), 4.23 (2H, t, JZ
3
2
7
.5 Hz, CH ), 6.92–6.96 (1H, m, ArH), 7.18 (2H, d, JZ
2
0
4
.3.4. Benzoic acid N -(4-chlorobenzylidene)-N-(3-oxo-
7.8 Hz, ArH), 7.32–7.36 (4H, m, ArH), 7.49 (1H, s, CH),
7.58 (2H, d, JZ7.8 Hz, ArH); C NMR (CDCl , 75 MHz,
1
3
butyl)hydrazide 9b. Colorless solid; mp 133–135 8C
recrystallized from dichloromethane and petroleum
ether); IR (CH Cl ) n 3441, 3055, 2987, 1716 (C]O),
3
(
TMS) d 21.3, 30.5, 38.3, 39.4, 115.0, 120.6, 126.0, 129.1,
129.3, 132.0, 133.6, 137.8, 146.6, 206.9; MS (EI) m/z 280
2
2
K1
1
C
(M , 100), 223 (M K57, 69.40), 119 (M K161, 51.14),
C
C
1
658, 1414, 896 cm ; H NMR (CDCl , 300 MHz, TMS)
3
C C
106 (M K174, 90.55), 77 (M K203, 62.31); HRMS
d 2.24 (3H, s, CH ), 2.89 (2H, t, JZ7.2 Hz, CH ), 4.41 (2H,
t, JZ7.2 Hz, CH ), 7.27–7.32 (2H, m, ArH), 7.38–7.52 (5H,
m, ArH), 7.68–7.71 (2H, m, ArH), 7.79 (1H, s, CH);
NMR (CDCl , 75 MHz, TMS) d 30.3, 35.9, 39.3, 127.3,
3
2
C1
C
(M CH): 281.1648.
(MALDI) calcd for C H N O
18 21 2
Found: 281.1655.
2
1
3
C
3
0
1
1
0
28.2, 128.9, 129.8, 130.4, 133.0, 134.7, 135.4, 137.8,
C C
70.9, 206.5; MS (EI) m/z 328 (M , 3.53), 223 (M K105,
4.3.9. 4-[N -(4-Chlorobenzylidene)-N-phenylhydrazino]-
butan-2-one 11c. A yellow oil; IR (CH Cl ) n 3061, 2922,
1714 (C]O), 1596, 1497, 1404, 1145, 1087 cm ; H
NMR (CDCl , 300 MHz, TMS) d 2.21 (3H, s, CH ), 2.82
2
2
C C
.43), 188 (M K140, 8.38), 105 (M K223, 100), 77
K1
1
C
(M K251, 29.77). Anal. Calcd for C H N O Cl requires
18 17 2 2
C, 65.75; H, 5.21; N, 8.52%. Found: C, 65.58; H, 5.14; N,
3
3
(2H, t, JZ7.8 Hz, CH ), 4.24 (2H, t, JZ7.8 Hz, CH ), 6.96–
2
2
8
.61%.
.3.5. Benzoic acid N -isobutylidene-N-(3-oxobutyl)-
hydrazide 9c. Colorless oil; IR (CH Cl ) n 2965, 1716
7.00 (1H, m, ArH), 7.31–7.37 (6H, m, ArH), 7.45 (1H, s,
1
3
CH), 7.60 (2H, d, JZ8.4 Hz, ArH); C NMR (CDCl3,
75 MHz, TMS) d 30.5, 38.2, 39.5, 115.2, 121.1, 127.1,
128.7, 129.2, 130.3, 133.3, 135.0, 146.3, 206.7; MS (EI) m/z
0
4
2
2
K1
1
C
C
C
(
C]O), 1655, 1417, 1326, 1051, 715 cm
;
H NMR
CDCl , 300 MHz, TMS) d 1.01 (3H, s, CH ), 1.03 (3H, s,
300 (M , 51.47), 243 (M K57, 48.44), 119 (M K181,
67.18), 106 (M K194, 71.59), 77 (M K223, 78.15);
C
C
(
CH ), 2.21 (3H, s, CH ), 2.46–2.52 (1H, m, CH), 2.78 (2H,
3
3
C1
C
(M CH):
HRMS (MALDI) calcd for C H N OCl
17 18 2
3
3
t, JZ7.5 Hz, CH ), 4.24 (2H, t, JZ7.5 Hz, CH ), 7.12 (1H,
301.1102. Found: 301.1114.
2
2
d, JZ4.5 Hz, CH), 7.32–7.41 (3H, m, ArH), 7.63–7.66 (2H,
1
m, ArH); C NMR (CDCl , 75 MHz, TMS) d 19.4, 30.0,
3
3
4.3.10. 1,3-Diphenyl-4,5-dihydro-1H-pyrazole 12. This a
known compound. H NMR (CDCl , 300 MHz, TMS) d
1
1 1
3
2
5
1
1.6, 35.6, 39.1, 127.0, 129.5, 129.8, 134.8, 148.2, 170.4,
3
C C
06.4; MS (EI) m/z 261 (M C1, 3.28), 217 (M K43,
2.08 (3H, s, CH ), 2.83 (2H, t, JZ9.6 Hz, CH ), 3.66 (2H, t,
3
2
C
C
7.84), 188(M K72, 8.37), 105 (M K155,100), 77(M K
C
JZ9.6 Hz, CH ), 6.78–6.83 (1H, m, ArH), 6.98–7.01 (2H,
2
C1
1
m, ArH), 7.23–7.28 (2H, m, ArH); This H NMR spectro-
83, 53.44); HRMS (MALDI) calcd for C H N O
5 21 2 2
1
C
(
M CH): 261.1598. Found: 261.1599.
scopic data is in consistent with those reported in
literature.
1
2
4.3.6. (3-Methyl-4,5-dihydropyrazol-1-yl)phenylmetha-
none 10. Colorless solid; mp 90–93 8C (recrystallized
1
13
1
The H and C NMR spectroscopic data of 3a-d: H NMR
(CDCl , 300 MHz, TMS) d 2.16 (3H, s, CH ), 2.41 (3H, s,
from dichloromethane and petroleum ether); IR (CH Cl )
2
2
3
3
K1
1
n 3460, 1634 (C]O), 1454, 1375, 1169, 695 cm ; H
NMR (CDCl , 300 MHz, TMS) d 2.04 (3H, s, CH ), 2.85
CH ), 2.76–2.81 (1H, m, CHD), 3.82 (2H, m, CH ), 7.31
3 2
(2H, d, JZ8.4 Hz, ArH), 7.39–7.41 (3H, m, ArH), 7.64–
3
3
(
7
2H, t, JZ9.9 Hz, CH ), 4.09 (2H, t, JZ9.9 Hz, CH ), 7.37–
7.68 (2H, m, ArH), 7.74 (2H, d, JZ8.4 Hz, ArH), 8.10 (1H,
2
2
1
3
.45 (3H, m, ArH), 7.84–7.86 (2H, m, ArH); C NMR
13
s, CH); C NMR (CDCl , 75 MHz, TMS) d 21.3, 29.9,
3
(
CDCl , 75 MHz, TMS) d 16.1, 35.2, 44.7, 127.5, 129.4,
3
41.3, 43.5 (t, JZ3.75 Hz, CHD), 127.5, 128.0, 128.5, 129.3,
130.4, 133.4, 133.4, 144.0, 151.6, 205.1.
C
30.6, 134.4, 158.4, 166.5; MS (EI) m/z 188 (M , 27.72),
1
1
1
6
C
05 (M K83, 100), 77 (M K111, 47.82), 51 (M K137,
C
C
4.09). Anal. Calcd for C H N O requires C, 70.19; H,
1 12 2
1
.43; N, 14.88%. Found: C, 70.13; H, 6.09; N, 14.71%.
Acknowledgements
4.3.7. 4-(N-Benzylidene-N-phenyl-hydrazino)-butan-2-
one 11a. A yellow oil; IR (CH Cl ) n 3059, 3027, 1713
We thank the State Key Project of Basic Research (Project
973) (No. G2000048007), Shanghai Municipal Committee
of Science and Technology, and the National Natural
Science Foundation of China for financial support
(20025206, 203900502, and 20272069).
2
2
K1
C]O), 1592, 1496, 1394, 1266, 1164, 1144 cm ; H
1
(
NMR (CDCl , 300 MHz, TMS) d 2.20 (3H, s, CH ), 2.81
3
3
(
2H, t, JZ7.5 Hz, CH ), 4.24 (2H, t, JZ7.5 Hz, CH ), 6.93–
2 2

7288
G.-L. Zhao, M. Shi / Tetrahedron 61 (2005) 7277–7288
5. The reaction of phenyl hydrazone with methyl vinyl ketone
Supplementary data
was reported in the following reference. The corresponding
adduct was obtained in 40% yield. Snider, B. B.; Conn,
R. S. E.; Sealfon, S. J. Org. Chem. 1979, 44, 218–221.
. For the previous literature on the Michael addition of
sulfonamides to activated olefins. see: Fraser, F. A.; Proctor,
G. R.; Redpathb, J. J. Chem. Soc., Perkin Trans. 1 1992,
445–448.
Supplementary data associated with this article can be found
at 10.1016/j.tet.2005.04.071
6
7
1
H NMR spectra for aza-Michael addition products 3–6, 9,
11, and cyclized products 7, 8, 10, and 12. This material is
available free of charge via internet.
. Reactions of PhNHNH with MVK have been reported in the
2
following references, but in very low yields. See: (a) Maire, M.
Bull. Soc. Chim. Fr. 1908, 3, 277–278. (b) Blaise, E. E.; Maire,
M. C.R. Hebd. Seances Acad. Sci. 1906, 142, 216–220. (c)
Blaise, E. E.; Maire, M. Bull. Soc. Chim. Fr. 1908, 3, 268–270.
References and notes
(
d) Reaction of carbazates with acrylamide has also been
reported in the following reference. See: Gray, C. J.; Quibell,
M.; Jiang, K.-L.; Baggett, N. Synthesis 1991, 141–146.
. (a) Auwers, K. V.; L a¨ mmerhirt, E. Chem. Ber. 1921, 54,
1
. (a) Ciganek, E. Org. React. 1997, 51, 201–350. (b) Basavaiah,
D.; Rao, P. D.; Hyma, R. S. Tetrahedron 1996, 52, 8001–8062.
8
9
(
c) Basavaiah, D.; Rao, A. J.; Satyanarayana, T. Chem. Rev.
003, 103, 811–892.
. (a) Morita, K.; Suzuki, Z.; Hirose, H. Bull. Chem. Soc. Jpn.
968, 41, 2815–2819. (b) Baylis, A. B.; Hillman, M. E. D.
1000–1024. (b) Raiford, L. C.; Entrikin, J. B. J. Am. Chem.
Soc. 1933, 55, 1125–1128.
2
2
3
. For a recent accounts of base promoted Michael addition,
please see: Rodriguez, J. Synlett 1999, 505–518.
1
German Patent 2155113, 1972.
1
1
0. For Michael addition reactions catalyzed by inorganic base,
please see: (a) Ma, S.-M.; Yin, S.-H.; Li, L.-T.; Tao, F.-G. Org.
Lett. 2002, 4, 505–507. (b) Khim, D. Y.; Suh, K. H.; Huh,
S. C.; Lee, K. Synth. Commun. 2001, 3315–3322.
. (a) Shi, M.; Xu, Y.-M. Chem. Commun. 2001, 1876–1877. (b)
Shi, M.; Xu, Y.-M. Eur. J. Org. Chem. 2002, 696–701. (c) Shi,
M.; Xu, Y.-M.; Zhao, G.-L.; Wu, X.-F. Eur. J. Org. Chem.
2002, 3666–3679. (d) Shi, M.; Xu, Y.-M. J. Org. Chem. 2003,
1. For Michael addition reactions catalyzed by nucleophilic
phosphine Lewis base, please see: (a) Bhuniya, D.; Mohan, S.;
Narayanan, S. Synthesis 2003, 1018–1024. (b) Phosphine-
catalyzed hydration and hydroalkoxylation of activated olefins
have been reported: Stewart, I. C.; Bergman, R. G.; Toste,
F. D. J. Am. Chem. Soc. 2003, 125, 8696–8697 and references
cited therein. (c) Wang, L.-C.; Luis, A. L.; Apapiou, K.; Jang,
H.-Y.; Krische, M. J. J. Am. Chem. Soc. 2002, 124,
2402–2403. (d) Frank, S. A.; Mergott, D. J.; Roush, W. R.
J. Am. Chem. Soc. 2002, 124, 2404–2405. (e) Takashi, Y.;
Shojiro, S. Chem. Lett. 1982, 1587–1590. (f) Islami, M. R.;
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Synlett 2004, 1707–1710.
68, 4784–4790. (e) Zhao, G. L.; Huang, J.-W.; Shi, M. Org.
Lett. 2003, 5, 4737–4739.
4
. DABCO-catalyzed Michael addition reaction was involved in
the dimerization of propiolates: (a) Matsuya, Y.; Hayashi, K.;
Nemoto, H. J. Am. Chem. Soc. 2003, 125, 646–647. (b)
Winterfeldt, E. Chem. Ber. 1964, 97, 1952–1958. (c) Acheson,
R. M.; Ansell, P. J.; Murray, J. R. J. Chem. Res. (S) 1986,
378–379. (d) Medion-Simon, M.; Pindur, U. Helv. Chim. Acta
1991, 74, 430–437. Also see: (e) Chen, Y.; McDaid, P.; Deng,
L. Chem. Rev. 2003, 103, 2965–2983. (f) Ramachandran,
P. V.; Rudd, M. T.; Reddy, M. V. R. Tetrahedron Lett. 1999,
4
0, 3819–3822. (g) Kice, J. L.; Lotey, H. J. Org. Chem. 1988,
3, 3593–3597. (h) Clark, W. M.; Tickner-Eldridge, A. M.;
5
Huang, G. K.; Pridgen, L. N.; Olsen, M. A.; Mills, R. J.;
Lantos, I.; Baine, N. H. J. Am. Chem. Soc. 1998, 120,
12. (a) Fliege, W.; Huisgen, R.; Cloris, J. S.; Knupfer, H. Chem.
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4550–4551. (i) Lee, H. J.; Kim, T. Y.; Kim, J. N. Synth.
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