Enantioselective allylic substitution of Morita-Baylis-Hillman adducts catalyzed by planar chiral [2.2]paracyclophane monophosphines

Article abstract of DOI:10.1016/j.tetasy.2007.08.005

Planar chiral [2,2]cyclophane monophosphines are efficient catalyst in the reaction of Morita-Baylis-Hillman adducts with phthalimide. The corresponding allylic substituted products were afforded in high yields and in good to moderate ee.

Full text of DOI:10.1016/j.tetasy.2007.08.005

Tetrahedron: Asymmetry 18 (2007) 1990–1994
Enantioselective allylic substitution of Morita–Baylis–Hillman
adducts catalyzed by planar chiral [2.2]paracyclophane
monophosphines
Tang-Zhi Zhang, Li-Xin Dai and Xue-Long Hou*
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry,
Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China
Received 26 July 2007; accepted 6 August 2007
Abstract—Planar chiral [2,2]cyclophane monophosphines are efficient catalyst in the reaction of Morita–Baylis–Hillman adducts with
phthalimide. The corresponding allylic substituted products were afforded in high yields and in good to moderate ee.
ꢀ 2007 Elsevier Ltd. All rights reserved.
1. Introduction
use of these organophosphines as catalysts. Herein, we
report the application of planar chiral [2.2]paracyclophane
monophosphines as organocatalysts in the asymmetric
allylic substitution of MBH adducts.
The Morita–Baylis–Hillman reaction is one of the most
efficient protocols for the synthesis of a-methylene-b-hy-
droxy-carbonyl compounds, which are versatile intermedi-
ates for a variety of synthetically useful compounds.1,2
Much effort has been devoted to asymmetric Morita–Bay-
lis–Hillman reactions and applications of the reaction
products in natural products synthesis. Only a few reports
have focused on the enantioselective transformation of
Morita–Baylis–Hillman products via direct substitution
reactions, chiral tertiary amines and chiral Pd-complexes
being the catalyst studied.3,4 Organophosphine-catalyzed
allylic amination and allylic alkylation of MBH adducts
have also been reported.5 When (R)-Cl–MeOBIPHEP
was used as a catalyst, reaction of the MBH adduct,
obtained from p-nitrobenzaldehyde and methyl acrylate,
with phthalimide gave the allylic substituted product in
80% yield and in 56% ee. However, only one example
was given.5a To date, no asymmetric version of this trans-
formation has been reported using chiral monophosphines
as catalysts. Recently, we synthesized a series of planar chi-
ral [2.2]paracyclophane monophosphines using a chiral
palladacycle as a resolving reagent and applied them in
asymmetric catalysis.6 The role of planar chirality in
[2.2]paracyclophane has been described.6,7 To further
explore the applications of these planar chiral cyclophane
monophosphines in asymmetric catalysis, we studied the
2. Results and discussion
Using MBH adduct 1a as a substrate and phthalimide 2 as
a pronucleophile, the efficiency of cyclophane monophos-
phines (R)-4 was tested in THF (Eq. 1), and the results
are compiled in Table 1.
Table 1. Effect of catalysts on the allylic amination of MBH adducta
Entry
Catalyst
Time (h)
Yieldb (%)
eec (%)
1
2
3
4
5
6
7e
8f
(R)-4a
(R)-4b
(R)-4c
(R)-4d
(R)-4e
(R)-4f
(R)-4e
(R)-4e
62
48
72
48
24
36
24
24
90
95
Traced
86
95
75
62
95
60
15
—
8
71
36
69
71
a Molecular ratio: 1a/2/monophosphine = 100:200:20. Reaction run in
THF at rt.
b Isolated yield.
c Determined by chiral HPLC.
d Run at 50 ꢁC.
e 5 mol % of (R)-4e was used.
f 50 mol % of (R)-4e was used.
*
Corresponding author. E-mail: xlhou@mail.sioc.ac.cn
0957-4166/$ - see front matter ꢀ 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2007.08.005

T.-Z. Zhang et al. / Tetrahedron: Asymmetry 18 (2007) 1990–1994
1991
organophosphine (R)-4
OAc O
O
O
(20 mol%)
N
O
+
OMe
THF, rt
O
OMe
O
N
H
O2N
O2N
1a
2
3a
ð1Þ
a: R = C6H5
b: R = 4-MeOC6H4
c: R = 4-CF3C6H4
d: R = 3,5-(CH3)2C6H3
e: R = c-C6H11
f: R = i-Pr
PR2
(R)-4
Table 2. Effect of the solvents on the allylic amination of MBH adduct 1a
with 2a
It is not surprising that all organophosphines (R)-4 showed
catalytic activity; the allylic substituted products being pro-
vided in high yields with regiospecificity, except 4c with tri-
fluoromethyl as a substituent at the para-position of the
phenyl rings (entry 3) because of electronic reasons.
Regarding enantioselectivity, monophosphine 4e with two
cyclohexane rings on the P atom was the best, affording
product 3a in 71% ee and in 95% yield (entry 5) while
organophosphine 4a gave the product in 60% ee though
the yield was high (entry 1). However, product 3a was ob-
tained in only 36% ee using 4f with two isopropyl groups
on the P atom as a catalyst (entry 6). Another monophos-
phine, (R)-MOP 5,8 was also tested in the reaction. Product
3a was provided in 15% yield and in 25% ee. It can also be
seen from Table 1 that using 50 mol % of catalyst gave the
same results as that using 20 mol % (entry 8) while a de-
crease in the catalyst loading from 20 mol % to 5 mol %
influenced the enantioselectivity little (entry 7).
Entry
Solvent
Time (h)
Yieldb (%)
eec (%)
1
2
3
4
5
6
7
8
CH3CN
Toluene
CH2Cl2
t-BuOH
DME
Dioxane
Et2O
THF
48
48
48
48
24
24
48
24
38
49
54
49
92
98
49
95
20
46
30
29
72
61
48
71
a Molecular ratio: 1a/2/monophosphine = 100:200:20. Reaction run at rt.
b Isolated yield.
c Determined by chiral HPLC.
The reactions of MBH adducts derived from aromatic
aldehydes gave higher yields than those derived from ali-
phatic ones (entries 1–9 and 12–13 vs entries 10–11). Also
the reactions of MBH adducts derived from aromatic alde-
hydes and acrylates provided the products with better ee
than those derived from aliphatic ones (entries 1–9 vs
entries 10–11) or derived from methyl vinylketones (entries
1–9 vs entries 12–13). Change of the leaving group R3 from
OAc to OBoc has little influence on the results (entry 4 vs
entry 5). The highest ee (71%) and yield (95%) were pro-
vided when MBH acetate 1a was used (entry 1).
PPh2
(R)-5
Using monophosphine 4e, the effect of different solvents
was investigated (Table 2). The results showed that the
reactions in DME, THF and dioxane were completed in
24 h, giving product 3a in higher yields and ee values (en-
tries 5, 6, and 8) while those in other solvents needed more
time to complete and provided the product in lower yields
and in lower ee (entries 1–4 and 7).
OR3
O
(
R
)-4e (20 mol%)
O
O
O
+
N
R1
R2
THF, rt
O
O
N
H
R1
R2
2
3
1
Other pronucleophiles were also used in this phosphine-
catalyzed allylic substitution reaction. However, only low
yields were given in the reaction of 1a with p-MeOC6H4OH
or TsNH2 in the presence of 20 mol % of organophosphine
(R)-4a.
ð2Þ
Finally, 2-trimethylsilyloxy furan 6 was investigated as a
pronucleophile under the above reaction conditions. Corre-
sponding substituted product 7 was afforded in high yield,
high diastereoselectivity but moderate enantioselectivity
when MBH adduct 1a was reacted with 6 using 20 mol %
of (R)-4e as catalyst (Eq. 3).
To assess the feasibility of planar chiral [2.2]paracyclo-
phane monophosphine in this reaction, a series of MBH
adducts 1 were prepared5b,9–13 and used in this chiral phos-
phine-catalyzed allylic substitution reaction (Eq. 2, Table 3).

1992
T.-Z. Zhang et al. / Tetrahedron: Asymmetry 18 (2007) 1990–1994
Table 3. Allylic amination of MBH acetatesa
phosphines (R)-46 and Morita–Baylis–Hillman adducts
15b,9–13 were prepared using literature procedures.
Entry
Substrate 1
Yieldb (%)
eec (%)
R1
R2
R3
4.2. General procedure for preparation of Morita–Baylis–
Hillman adducts
1
2
3
4
5
6
7
8
9
10
11
12
13
b, 4-NO2C6H4
ba, 4-NO2C6H4
bb, 4-NO2C6H4
a, C6H5
aa, C6H5
ab, C6H5
OMe
OEt
OBut
OMe
OMe
OEt
OBut
OMe
OEt
OMe
OMe
Me
Ac
Ac
Boc
Ac
Boc
Ac
Boc
Ac
Boc
Ac
Ac
Ac
95
78
82
80
78
68
75
85
60
44
32
82
85
71
29
21
52
52
66
44
37
48
9
The mixture of aldehyde (50 mmol), activated alkene
(75 mmol) and DABCO (10 mmol) was stirred for 3 days.
Then pyridine (150 mmol) and dichloromethane (100 mL)
were added under stirring. The mixture was cooled to
0 ꢁC and acetyl chloride was added dropwise. Then the
reaction mixture was stirred for 4 h at 0 ꢁC. It was
quenched with 1 N HCl, and the aqueous layer was
extracted with ethyl acetate (2 · 100 mL). The combined
organic layer was washed with water (2 · 50 mL) and
NaHCO3 (2 · 50 mL), dried over Na2SO4. Removal of
the solvent in vacuum and purification by column chroma-
tography (ethyl acetate/petroleum ether = 1:5–1:10) gave
the product.
ac, C6H5
c, 4-ClC6H4
d, 4-MeOC6H4
e, Et
f, Pri
g, C6H5
h, 4-NO2C6H4
11
17
10
Me
Ac
a Molecular ratio: 1/2/(R)-4e = 100:200:20. Reaction run in THF at rt.
b Isolated yield.
c Determined by chiral HPLC.
O
O
O
OAc O
(
R
)-4e (20 mol%)
H
H
+
OMe
OTMS
ð3Þ
OMe
O
THF, rt
60h
1a
6
7
85% yield
>95% dr, 36%ee
3. Conclusion
4.2.1. Methyl 2-[(tert-butoxycarbonyloxy)(phenyl)methyl]-
acrylate 1aa. Yield: 46%; H NMR (300 MHz, CDCl3)
1
In summary, a planar chiral [2.2]paracyclophane mono-
phosphine has been successfully applied as an organocata-
lyst in asymmetric allylic amination of MBH adducts. Up
to 71% ee was achieved using (R)-4e as a catalyst, which
represents one of the best results in organic molecule-cata-
lyzed allylic amination reactions of MBH adducts.3a,b,5b
These results also reflect the role of planar chirality in
[2,2]cyclophane.6,14 Further applications of planar chiral
[2.2]paracyclophane monophosphine in asymmetric cata-
lysis are in progress.
d 7.40–7.32 (m, 5H), 6.48 (s, 1H), 6.41 (s, 1H), 5.91 (s,
1H), 3.71 (s, 3H), 1.46 (s, 9H); 13C NMR (CDCl3,
75 MHz) d 165.3, 152.3, 139.6, 137.4, 128.4, 127.6, 125.8,
82.6, 75.7, 52.0, 27.7; ESI-MS m/z: 315 [M++Na+], 347
[M++MeOH+Na+]. IR (KBr): 2981, 1747, 1439, 1370,
1278, 1158, 1086, 964, 883, 703 cmꢀ1; HRMS (MALDI):
Anal. Calcd for C16H20O5Na+: 315.1208. Found: 315.1203.
4.2.2. t-Butyl 2-[acetoxy(phenyl)methyl]acrylate 1ac.
1
Yield: 55%; H NMR (300 MHz, CDCl3) d 7.37–7.31 (m,
5H), 6.42 (s, 1H), 6.33 (s, 1H), 5.79 (s, 1H), 1.46 (s, 9H),
1.36 (s, 9H); 13C NMR (CDCl3, 75 MHz) d 164.1, 152.4,
128.3, 127.8, 124.6, 82.5, 81.4, 76.1, 27.8, 27.7; EI-MS m/z
(relative intensity %): 222 (15), 204 (21), 132 (28), 105
(23), 57 (100). IR (KBr): 2980, 1747, 1369, 1279, 1152,
1086, 968, 883, 756, 700 cmꢀ1; HRMS (MALDI): Anal.
Calcd for C19H26O5Na+: 357.1677. Found: 357.1672.
4. Experimental
4.1. General
All reactions were performed under an atmosphere of ar-
gon using oven-dried glassware. Solvents were treated prior
to use according to the standard method. 1H NMR spectra
were recorded in CDCl3 or C6D6 at room temperature.
Chemical shifts are given in parts per million relative to
TMS as an internal standard. Optical rotations were mea-
sured with a thermally jacketed 10 cm cell at 25 ꢁC (concen-
tration c given as g/100 mL). IR spectra were measured in
cmꢀ1. Ee values were determined by chiral HPLC. The
commercially available reagents were used as received with-
out further purification. Chiral [2.2]paracyclophane mono-
4.2.3. t-Butyl 2-[acetoxy(40-nitrophenyl)methyl]acrylate 1bb.
Yield: 60%; 1H NMR (300 MHz, CDCl3) d 8.20 (d,
J = 8.8 Hz, 2H), 7.58 (d, J = 8.8 Hz, 2H), 6.48 (s, 1H),
6.38 (s, 1H), 5.89 (s, 1H), 1.46 (s, 9H), 1.40 (s, 9H); 13C
NMR (CDCl3, 75 MHz) d 163.6, 152.1, 147.7, 145.2,
139.9, 128.5, 125.7, 123.6, 83.2, 81.9, 74.8, 27.9, 27.4; EI-
MS m/z (relative intensity %): 205 (6), 160 (9), 57 (100),
41 (22). IR (KBr): 2981, 1743, 1369, 1322, 1086, 968, 883,
756, 700 cmꢀ1
C19H25NO7Na+: 402.1523. Found: 402.1525.
; HRMS (MALDI): Anal. Calcd for

T.-Z. Zhang et al. / Tetrahedron: Asymmetry 18 (2007) 1990–1994
1993
4.2.4. Ethyl 2-[(tert-butoxycarbonyloxy)(40-methoxyphen-
yl)methyl]acrylate 1d. Yield: 18%; H NMR (300 MHz,
ative intensity %): 367 (M+ <1), 334 (7), 147 (50), 104 (57),
76 (100), 50 (39).
1
CDCl3) d 7.32 (d, J = 8.6 Hz, 2H), 6.86 (d, J = 8.7 Hz,
2H), 6.42 (s, 1H), 6.38 (s, 1H), 5.90 (s, 1H), 4.16–4.12 (m,
2H), 3.79 (s, 3H), 1.46 (s, 9H), 1.22 (t, J = 7.4 Hz, 3H);
13C NMR (CDCl3, 75 MHz) d 164.9, 159.6, 152.4, 139.9,
129.5, 129.2, 124.8, 113.7, 82.4, 75.6, 60.8, 55.2, 27.7,
14.0; ESI-MS m/z: 359 [M++Na+], 391 [M++MeOH+-
Na+]. IR (KBr): 2981, 1747, 1613, 1515, 1251, 1159,
1034, 966, 885 cmꢀ1; HRMS (MALDI): Anal. Calcd for
C18H24O6Na+: 359.1468. Found: 359.1465.
4.3.5. N-[2-(Ethoxycarbonyl)-1-(40-nitrophenyl)allyl]-phthal-
imide 3ba. Yield: 78%; ee: 29% by HPLC Chiralcel OD-H
column with hexane/isopropanol = 85:15, flow rate =
0.7 mL/min, tR1 = 17.29 min, tR2 = 20.88 min; 1H NMR
(300 MHz, CDCl3) d 8.22 (d, J = 8.9 Hz, 2H), 7.89–7.75
(m, 4H), 7.63 (d, J = 8.5 Hz, 2H), 6.64 (s, 1H), 6.52 (s,
1H), 5.63 (m, 1H), 4.18–4.14 (m, 2H), 1.18 (t, J = 7.4 Hz,
3H); 13C NMR (CDCl3, 75 MHz) d 167.6, 165.0, 147.5,
144.2, 136.5, 134.4, 134.3, 131.5, 129.7, 123.8, 123.6, 61.4,
53.7, 13.9; MALDI-MS m/z: 403 [M++Na+]; IR (KBr):
2925, 1717, 1521, 1348, 856, 721, 531 cmꢀ1; HRMS (MAL-
DI): Anal. Calcd for C20H16N2O6Na+: 403.09000. Found:
403.09006.
4.3. General procedure for asymmetric allylic nucleophilic
substitution of Morita–Baylis–Hillman adducts
To a reaction vessel charged with substrate 1 (0.5 mmol),
phthalimide 2 or 2-trimethylsilyloxy furan 6 (1 mmol),
and (R)-[2.2]paracyclophane monophosphine 4e (0.1
mmol), was added THF (1.6 mL). The reaction was al-
lowed to stir at room temperature until complete consump-
tion of substrate, at that point the reaction mixture was
evaporated onto silica gel and the product was purified
by silica gel chromatography.
4.3.6.
N-[2-tert-Butoxycarbonyl-1-(40-nitrophenyl)allyl]-
phthalimide 3bb. Yield: 82%; ee: 21% by HPLC Chiralcel
OD-H column with hexane/isopropanol = 85:15, flow
rate = 0.7 mL/min, tR1 = 13.63 min, tR2 = 21.96 min; 1H
NMR (300 MHz, CDCl3) d 8.21 (d, J = 8.9 Hz, 2H), 7.87
(m, 2H), 7.75 (m, 2H), 7.62 (d, J = 8.7 Hz, 2H), 6.52 (s,
1H), 6.44 (s, 1H), 5.50 (s, 1H), 1.34 (s, 9H); 13C NMR
(CDCl3, 75 MHz) d 167.5, 164.0, 147.4, 144.5, 137.9,
134.4, 131.5, 129.7, 128.3, 123.6, 81.9, 53.9, 27.7; EI-MS
m/z (relative intensity %): 334 (15), 306 (12), 188 (7), 57
4.3.1. N-[(2-Methoxycarbonyl-1-phenyl)allyl]-phthalimide
3a.5a Yield: 80%; ee: 52% by HPLC Chiralcel OD-H col-
umn with hexane/isopropanol = 70:30, flow rate = 0.6 mL/
min, tR1 = 7.29 min, tR2 = 13.40 min; 1H NMR (300 MHz,
CDCl3) d 7.85–7.81 (m, 2H), 7.72–7.69 (m, 2H), 7.45–7.30
(m, 5H), 6.56 (s, 1H), 6.39 (s, 1H), 5.63 (s, 1H), 3.70 (s, 3H);
ESI-MS m/z: 322 [M++1], 339 [M++H2O].
(100). IR (KBr): 2928, 1727, 1523, 1348, 1148, 722 cmꢀ1
;
HRMS (MALDI): Anal. Calcd for C22H20N2O6Na+:
431.1216. Found: 431.1214.
4.3.7. N-[2-Methoxycarbonyl-1-(40-chlorophenyl)allyl]-phthal-
imide 3c. Yield: 85%; ee: 37% by HPLC Chiralcel OD-H
column with hexane/isopropanol = 85:15, flow rate =
0.6 mL/min, tR1 = 8.48 min, tR2 = 12.10 min; 1H NMR
(300 MHz, CDCl3) d 7.85–7.71 (m, 4H), 7.40–7.27 (m,
4H), 6.57 (s, 1H), 7.37 (s, 1H), 5.64 (s, 1H), 3.70 (s, 3H);
ESI-MS m/z: 499 [M++MeOH+Na+]. IR (KBr): 2924,
1724, 1492, 1385, 1089, 723 cmꢀ1; HRMS (MALDI): Anal.
Calcd for C19H14NO4ClNa+: 378.0509. Found: 378.0504.
4.3.2.
N-[(2-Ethoxycarbonyl-1-phenyl)allyl]-phthalimide
3ab. Yield: 68%; ee: 66% by HPLC Chiralpak AD-H col-
umn with hexane/isopropanol = 87:13, flow rate = 0.7 mL/
min, tR1 = 19.39 min, tR2 = 22.14 min; 1H NMR
(300 MHz, CDCl3) d 7.83 (m, 2H), 7.70 (m, 2H), 7.45–
7.30 (m, 5H), 6.56 (s, 1H), 6.37 (s, 1H), 5.80 (s, 1H),
4.16–4.10 (m, 2H), 1.14 (t, J = 6.8 Hz, 3H); EI-MS m/z
(relative intensity %): 335 (M++5), 289 (100), 261 (90),
233 (55).
4.3.8.
N-[2-Ethoxycarbonyl-1-(40-methoxyphenyl)allyl]-
4.3.3. N-[(2-tert-Butoxycarbonyl-1-phenyl)allyl]-phthalimide
3ac. Yield: 75%; ee: 44% by HPLC Chiralpak AD-H col-
umn with hexane/isopropanol = 85:15, flow rate = 0.6 mL/
min, tR1 = 7.46 min, tR2 = 11.23 min; 1H NMR (300 MHz,
CDCl3) d 7.85–7.70 (m, 4H), 7.46–7.31 (m, 5H), 6.46 (s,
1H), 6.31 (s, 1H), 5.44 (s, 1H), 1.31 (s, 9H); 13C NMR
(CDCl3, 75 MHz) d 167.8, 164.7, 139.2, 137.4, 134.0,
131.8, 128.8, 128.5, 128.0, 123.3, 81.4, 54.9, 27.8; EI-MS
m/z (relative intensity %): 307 (23), 289 (80), 261 (100),
233 (37). IR (KBr): 2978, 1721, 1386, 1251, 1145, 721,
531 cmꢀ1; HRMS (MALDI): Anal. Calcd for C22H21NO4-
Na+: 386.1362. Found: 386.1363.
phthalimide 3d. Yield: 60%; ee: 48% by HPLC Chiralcel
OD-H column with hexane/isopropanol = 85:15, flow
rate = 0.6 mL/min, tR1 = 10.98 min, tR2 = 14.28 min; 1H
NMR (300 MHz, CDCl3) d 7.83–7.68 (m, 4H), 7.39 (d,
J = 8.6 Hz, 2H), 6.86 (d, J = 9.0 Hz, 2H), 6.53 (s, 1H),
6.32 (s, 1H), 5.59 (s, 1H), 4.14–4.10 (m, 2H), 1.14 (t, J =
7.0 Hz, 3H); ESI-MS m/z: 388 [M++Na+], 420
[M++MeOH+Na+]. IR (KBr): 2962, 1514, 1259, 1028,
716 cmꢀ1; HRMS (MALDI): Anal. Calcd for C21H19NO5-
Na+: 388.1144. Found: 388.1155.
4.3.9. N-[(2-Methoxycarbonyl-1-ethyl)allyl]-phthalimide 3e.
Yield: 44%; ee: 9% by HPLC Chiralcel OD-H column with
hexane/isopropanol = 85:15, flow rate = 0.6 mL/min,
tR1 = 6.92 min, tR2 = 8.33 min; 1H NMR (300 MHz,
CDCl3) d 7.84–7.81 (m, 2H), 7.73–7.69 (m, 2H), 6.54 (s,
1H), 6.08 (s, 1H), 5.18–5.12 (m, 1H), 3.73 (s, 3H), 0.97–
0.83 (m, 5H); ESI-MS m/z: 296 [M++Na+], 328
[M++MeOH+Na+]. IR (KBr): 2965, 1725, 1386, 1260,
4.3.4. N-[2-Methoxycarbonyl-1-(40-nitrophenyl)allyl]-phtha-
limide 3b.5a Yield: 95%; ee: 71% HPLC Chiralcel OD-H
column
with
hexane/isopropanol = 85:15,
flow
rate = 0.7 mL/min, tR1 = 19.50 min, tR2 = 23.43 min; 1H
NMR (300 MHz, CDCl3) d 8.20 (d, J = 8.9 Hz, 2H), 7.85
(m, 2H), 7.75 (m, 2H), 7.60 (d, J = 9.0 Hz, 2H), 6.63 (s,
1H), 6.52 (s, 1H), 5.66 (s, 1H), 3.72 (s, 3H); EI-MS m/z (rel-

1994
T.-Z. Zhang et al. / Tetrahedron: Asymmetry 18 (2007) 1990–1994
722 cmꢀ1; HRMS (MALDI): Anal. Calcd for C15H15NO4-
Na+: 296.0902. Found: 296.0893.
Program (2006CB806100), Chinese Academy of Sciences
and Science and Technology Commission of Shanghai
Municipality.
4.3.10. N-[(2-Methoxycarbonyl-1-iso-propyl)allyl]-phthal-
imide 3f. Yield: 95%; ee: 60% by HPLC Chiralcel OD-H
column with hexane/isopropanol = 85:15, flow rate =
0.6 mL/min, tR1 = 6.08 min, tR2 = 7.33 min; 1H NMR
(300 MHz, CDCl3) d 7.86–7.69 (m, 4H), 6.65 (s, 1H),
6.31 (s, 1H), 4.98 (m, 1H), 3.76 (s, 3H), 1.00 (d, J =
6.2 Hz, 3H), 0.88 (d, J = 8.0 Hz, 3H); ESI-MS m/z: 310
[M++Na+], 342 [M++MeOH+Na+]. IR (KBr): 3206,
1726, 1385, 1052, 717, 548 cmꢀ1; HRMS (MALDI): Anal.
Calcd for C16H17NO4Na+: 310.1055. Found: 310.1050.
References
1. For some reviews: (a) Basavaiah, A. D.; Rao, J.; Satyanara-
yana, T. Chem. Rev. 2003, 103, 811; (b) Masson, G.;
Housseman, C.; Zhu, J. Angew. Chem., Int. Ed. 2007, 46,
4614.
2. A variation using an imine has also been developed, see Ref.
1b.
3. (a) Kim, J. N.; Lee, H. J.; Gong, J. H. Tetrahedron Lett. 2002,
43, 9141; (b) Du, Y.-S.; Han, X.-L.; Lu, X.-Y. Tetrahedron
Lett. 2004, 45, 4967; (c) van Steenis, D. J. V. C.; Marcelli, T.;
Lutz, M.; Spek, A. L.; van Maarseveen, J. H.; Hiemstra, H.
Adv. Synth. Catal. 2007, 349, 281.
4. (a) Trost, B. M.; Tsui, H. C.; Toste, F. D. J. Am. Chem. Soc.
2000, 122, 3534; (b) Trost, B. M.; Thiel, O. R.; Tsui, H.-C. J.
Am. Chem. Soc. 2002, 124, 11616; (c) Thiel, O. R.; Trost, B.
M.; Tsui, H.-C. J. Am. Chem. Soc. 2003, 125, 13155; (d)
Trost, B. M.; Machacek, M. R.; Tsui, H.-C. J. Am. Chem.
Soc. 2005, 127, 7014.
5. (a) Cho, C.-W.; Kong, J.-R.; Krische, M. J. Org. Lett. 2004,
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try 2007, 18, 251.
7. (a) Hou, X.-L.; Wu, X.-W.; Dai, L.-X.; Cao, B.-X.; Sun, J.
Chem. Commun. 2000, 1195; (b) Wu, X.-W.; Hou, X.-L.; Dai,
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J.; Hou, X.-L. Tetrahedron: Asymmetry 2003, 14, 107; (d)
Wu, X.-W.; Zhang, T.-Z.; Yuan, K.; Hou, X.-L. Tetrahedron:
Asymmetry 2004, 15, 2357.
8. (a) Uozumi, Y.; Hayashi, T. J. Am. Chem. Soc. 1991, 113,
9887; (b) Uozumi, Y.; Tamahashi, A.; Lee, S.-Y.; Hayashi, T.
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4.3.11.
N-[(2-Acetyl-1-phenyl)allyl]-phthalimide
3g.5a
Yield: 82%; ee: 17% by HPLC Chiralcel OD-H column
with hexane/isopropanol = 85:15, flow rate = 0.7 mL/
min, tR1 = 20.21 min, tR2 = 31.77 min; 1H NMR (300
MHz, CDCl3) d 7.81–7.79 (m, 2H), 7.70–7.67 (m, 2H),
7.38–7.35 (m, 5H), 6.34 (s, 1H), 5.70 (s, 1H), 2.40 (s, 3H).
4.3.12. N-[2-Acetyl-1-(40-nitrophenyl)allyl]-phthalimide 3h.5a
Yield: 85%; ee: 10% by HPLC Chiralcel OD-H column
with hexane/isopropanol = 85:15, flow rate = 0.7 mL/
min, tR1 = 29.97 min, tR2 = 38.25 min; 1H NMR
(300 MHz, CDCl3) d 8.19 (d, J = 8.8 Hz, 2H), 7.85–7.71
(m, 4H), 7.56 (d, J = 8.6 Hz, 2H), 6.51 (s, 1H), 6.43 (s,
1H), 5.75 (s, 1H), 2.42 (s, 3H); 13C NMR (CDCl3,
75 MHz) d 144.9, 144.6, 134.3, 131.4, 129.5, 123.9, 123.6,
64.4, 53.1.
4.3.13. 2-[(5-Oxo-2,5-dihydro-furan-2-yl)-phenyl methyl]-
acrylic acid methyl ester 7.5b Yield: 59%; dr >95%; ee:
29% by HPLC Chiralcel OD column with hexane/isopro-
panol = 70:30, flow rate = 0.7 mL/min, tR1 = 14.37 min,
1
tR2 = 20.21 min; H NMR (300 MHz, CDCl3) d 7.35–7.29
(m, 6H), 6.50 (m, 1H), 6.10 (m, 1H), 5.93 (s, 1H), 5.55 (d,
J = 8.7 Hz, 1H), 4.12 (d, J = 8.6 Hz, 2H), 3.69 (s, 3H).
13C NMR(CDCl3, 75 MHz) d 172.5, 166.5, 155.5, 138.0,
137.8, 128.8, 128.3, 127.7, 127.5, 121.8, 83.2, 52.1, 49.9.
9. Furstner, A.; Voigtlander, D. Synthesis 2000, 959.
¨
10. Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.;
Raimondi, L. J. Org. Chem. 1995, 60, 4697.
11. Nilov, D.; Ra¨cker, R.; Reiser, O. Synthesis 2002, 2232.
12. Patra, A.; Roy, A. K.; Batra, S.; Bhaduri, A. P. Synlett 2002,
1819.
13. Foucaud, A.; de Rouille, E. Synthesis 1990, 787.
14. Pye, P. J.; Rossen, K.; Reamer, R. A.; Tsou, N. N.;
Volante, R. P.; Reider, P. J. J. Am. Chem. Soc. 1997, 119,
6207.
Acknowledgments
Financially supported by National Natural Science Foun-
dation of China, Major Basic Research Development