From isonitrile to nitrile via ketenimine intermediate: Palladium-catalyzed 1,1-carbocyanation of allyl carbonate by α-isocyanoacetate

Article abstract of DOI:10.1016/j.tet.2018.10.032

A palladium-catalyzed 1,1-carbocyanation of allyl carbonate by α-quaternary α-isocyanoacetate was developed. Formation of ketenimine followed by homolysis of the C–N bond and recombination of the resulting caged radical pair was proposed to account for the formation of the unusual coupling product, the β-cyano-γ,δ-unsaturated ester.

Full text of DOI:10.1016/j.tet.2018.10.032

Accepted Manuscript
From isonitrile to nitrile via ketenimine intermediate: Palladium-catalyzed 1,1-
carbocyanation of allyl carbonate by α-isocyanoacetate
Guanyinsheng Qiu, Charlotte Sornay, David Savary, Sheng-Cai Zheng, Qian Wang,
Jieping Zhu
PII:
S0040-4020(18)31238-9
10.1016/j.tet.2018.10.032
TET 29865
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 12 September 2018
Accepted Date: 15 October 2018
Please cite this article as: Qiu G, Sornay C, Savary D, Zheng S-C, Wang Q, Zhu J, From isonitrile to
nitrile via ketenimine intermediate: Palladium-catalyzed 1,1-carbocyanation of allyl carbonate by α-
isocyanoacetate, Tetrahedron (2018), doi: https://doi.org/10.1016/j.tet.2018.10.032.
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ACCEPTED MANUSCRIPT
Graphical Abstract
From Isonitrile to Nitrile via Ketenimine
Intermediate: Palladium-catalyzed 1,1-
Carbocyanation of Allyl Carbonate by α-
Isocyanoacetate
Leave this area blank for abstract info.
Guanyinsheng Qiu, Charlotte Sornay, David Savary,
*
Sheng-Cai Zheng, Qian Wang and Jieping Zhu
Institute of Chemical Sciences and Engineering,
Ecole Polytechnique Fédérale de Lausanne,
EPFL-SB-ISIC-LSPN, CH-1015 Lausanne, Switzerland

1
ACCEPTED MANUSCRIPT
Tetrahedron
journal homepage: www.elsevier.com
From Isonitrile to Nitrile via Ketenimine Intermediate: Palladium-catalyzed 1,1-
Carbocyanation of Allyl Carbonate by α-Isocyanoacetate
‡
*
Guanyinsheng Qiu, Charlotte Sornay, David Savary, Sheng-Cai Zheng, Qian Wang, and Jieping Zhu
Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, CH-1015 Lausanne, Switzerland
—
——
*
A
C
R
or
T
re
I
sp
C
on
L
di
E
ng
I
a
N
uth
F
or
O
. E-mail: jieping.zhu@epfl.ch
ABSTRACT
‡
Present address: College of Biological, Chemical Science and Engineering,
Jiaxing University, 118 Jiahang Road, Jiaxing 314001, China
Article history:
Received
A palladium-catalyzed 1,1-carbocyanation of allyl carbonate by α-quaternary α-isocyanoacetate
was developed. Formation of ketenimine followed by homolysis of the C-N bond and
recombination of the resulting caged radical pair was proposed to account for the formation of
the unusual coupling product, the β-cyano-γ,δ-unsaturated ester.
Received in revised form
Accepted
Available online
2
009 Elsevier Ltd. All rights reserved.
Keywords:
palladium
allyl carbonate
isocyanide
isocyanoacetate
ketenimine
nitrile
radical
1
.
Introduction
Ketenimines are an important class of reactive species which
show very rich chemistry and are well exploited in organic
1-3
synthesis. One particular type of reaction is the isomerization
of ketenimines to nitriles via a formal 1,3-alkyl migration process.
Homolytic cleavage of the C-N bond followed by recombination
of the resulting caged radical pair through C-C bond formation
4
accounts for this formal 1,3-rearrangement process (Scheme 1a).
In connection with our interest in exploiting the diverse
5
reactivities of isocyanides, we recently reported palladium-
catalyzed reactions of isocyanides 1 with allyl carbonates 2
6
7
8
(
Scheme 1b), propargyl carbonates and α-haloketones. All
these reactions produced ketenimine intermediates 3 that can be
isolated or be in situ converted to β,γ-unsaturated amides and
9
diverse heterocycles. Concurrently, the groups of Yang, Wu and
10
Jian reported similar transformations involving the in situ
generated ketenimine intermediates.
Scheme 1. Pd-catalyzed synthesis of ketenimine and its
subsequent transformations.
Exploring the application scope of the reaction shown in
Scheme 1b, we replaced the simple isonitrile by α-quaternary-α-
isocyanoacetate. Interestingly, the reaction produced a new
to the best of knowledge, unprecedented, we set out to examine
this reaction in detail. We report herein that the Pd-catalyzed
reaction of α-quaternary-α-isocyanoacetates
1
with allyl
product that was identified as β-cyano-γ,δ-unsaturated ester
3
carbonates 2 represents indeed a general way to access β-cyano-
γ,δ-unsaturated esters 4. Mechanistic studies suggested that the
reaction went through a ketenimine intermediate 3 which
underwent homolytic cleavage of the C-N bond followed by
recombination of the resulting caged radical pair to afford the
observed product.
(
Scheme 1c). Since such a 1,1-carbocyanation of a Csp carbon is,

2
Tetrahedron
ACCEPTED MAev
N
en
U
t.
S
It
C
is
R
worth noting that the aryl chloride and even aryl
I
P
T
bromide was compatible to this Pd(0) catalyzed process.
2
.
Results and discussion
The reaction of ethyl 2-isocyano-2,3-dihydro-1H-indene-2-
11,12
O
carboxylate (1a)
with cinnamyl ethyl carbonate (2a) was
CN
CN
R
O
OEt
chosen as a benchmark reaction (Table 1). Under the conditions
2
Conditionsa
R
COOEt
+
+
optimized previously for the synthesis of ketenimines (1.0 mol%
EtOOC
R
6
of Pd(OAc) , THF, 50 °C), 4a was isolated in 46% yield (entry
NC
COOEt
2
1
(
). Addition of Et N (2.0 equiv) decreased yield of 4a to 12%
4
5 E/Z
3
1
a
entry 2), while adding other bases (K CO , K PO , KTFA,
2 3 3 4
CN
EtOOC
tBuOK, DBU) or acid (AcOH) led to the complete degradation.
Among ligands screened (dppp, DPEPhos, XantPhos, XPhos,
DavePhos, PhDavephos, tBuDavePhos, (S)-tBuPHOX, tri-t-
butylphosphonium
tetrafluoroborate,
1,10-phenanthroline),
a 60%, 4/1b
4
DavePhos was the most effective to give the desired product 4a
in 34% isolated yield (entry 3). Various solvents were next
examined (DCE, MeCN, dioxane, toluene, THF, DMF, EtOH)
and DCE was found to give a slightly better yield of 4a (entries
CN
CN
Me CN
EtOOC
EtOOC
OMe
EtOOC
Me
b 46%, 4/1b
Me
4d 54%, 4/1b
4
4c 61%, 4/1b
3
,4). Using DCE as solvent, in the presence of DavePhos or
CN
CN
EtOOC
tBuDavePhos, similar yields were obtained (entries 4,5).
Increasing (80 °C) or decreasing (rt) the temperature afforded the
desired product with lower yields (entries 6,7). With these results
in hand, the influence of palladium sources was reinvestigated
and Pd(PPh ) turned out to be the catalyst of choice affording 4a
EtOOC
MeO
OMe
4
4
4
e 45%, 4/1b
4f 59%, 4/1b
CN
3
4
CN
in 60% yield (entry 8). Finally, the influence of the leaving group
of the allylic species was examined. Using allyl t-butyl carbonate,
acetate, allyl bromide and allyl chloride as reaction partners, the
isocyanide 2a was recovered. Finally, the optimum conditions
consisted of performing the reaction of 1a with 2a in DCE (0.1
M), in the presence of Pd(PPh ) at 55 °C. Under these conditions,
O
EtOOC
EtOOC
O
g 51%, 4/1b
4h 42%, 4/1b
CN
CN
EtOOC
EtOOC
3
4
Cl
Br
4
a was isolated together with its regioisomer 5a in 60% yield in a
i 47%, 4/1b
4j 53%, 4/1b
ratio of 4:1 (entry 8). The structure of 4a was determined by X-
13
Scheme 2. Pd-catalyzed coupling reaction of allyl carbonate and
isocyanide. Reaction conditions: allyl carbonate 2 (0.10 mmol),
ray crystallographic analysis.
a
Table 1. Pd-catalyzed coupling reaction of allyl carbonate and
isocyanide: Condition survey
isocyanide 1a (0.11 mmol), Pd(PPh ) (10 mol%) in DCE (1.0 mL, c
3 4
a
b
0
.1 M), 55 °C. The ratio of 4/5.
b
entry
Pd
ligand
solvent
base
-
yield(%) (4a/5a)
c
1
2
3
4
5
6
7
8
Pd(OAc)
2
-
THF
THF
THF
DCE
DCE
DCE
DCE
DCE
46 (11:1)
Pd(OAc)
Pd(OAc)
Pd(OAc)
Pd(OAc)
Pd(OAc)
Pd(OAc)
2
-
Et
3
N
12
34
47
48
2
2
2
2
2
DavePhos
DavePhos
tBuDavePhos
tBuDavePhos
tBuDavePhos
-
-
-
-
-
d
41
e
40
Pd(PPh
3
)
4
60 (4/1)
Scheme 3. Pd-catalyzed coupling reaction of allyl carbonate and
a
isocyanide. Reaction conditions: allyl carbonate 2a (0.10 mmol),
a
Reaction conditions: 1a (0.11 mmol), 2a (0.10 mmol), Pd catalyst
b
isocyanide 1 (0.11 mmol), Pd(PPh ) (10 mol%) in DCE (1.0 mL, c
3 4
0.1 M), 100 °C. The ratio of 4/5. Reaction was performed at 55 °C.
(
10 mol%), ligand (20 mol%), solvent (1.0 mL, c 0.1 M), 55 °C.
b
c
c
d
Isolated yield. 1 mol% of catalyst. Reaction was performed at
8
e
0 °C. Reaction was performed at rt.
The scope of the isocyanides was then examined. As shown in
Scheme 3, the reaction of 2a with ethyl 1-isocyanocyclopentane-
The scope of this novel 1,1-carbocyanation protocol was next
examined varying firstly the structure of allyl carbonates 2
Scheme 2). Reaction of isocyanide 1a with cinnamyl ethyl
carbonates 2 bearing an electron-withdrawing or donating
substituent at different positions of the benzene ring participated
in the reaction to give the desired products (4a-4g, 4i-4j) in good
yields. (E)-Ethyl (3-(naphthalen-2-yl)allyl) carbonate was
converted to the corresponding coupling product 4h without
1
-carboxylate, ethyl 1-isocyanocyclobutane-1-carboxylate, or
ethyl 1-isocyanocyclohexane-1-carboxylate proceeded smoothly
providing the desired products 4k-4m, respectively, in good
yields. Ethyl 1-isocyanocyclopent-3-ene-1-carboxylate worked
well, affording the desired product 4n. Ethyl 4-cyanotetrahydro-
(
2
H-pyran-4-carboxylate participated also in the reaction,
however, producing the product 4o in lower yield (20%).

3
To get the mechanistic insight, following co
were carried out (Scheme 4). Performing the reaction of 1a with
a at 30 °C for 20-30 min under otherwise standard conditions
A
nt
C
ro
C
l e
E
xp
P
er
T
im
E
en
D
ts MAN
B
U
ase
S
d
C
o
R
n
IPth
T
ese results, a possible reaction pathway is
depicted in Scheme 5. Oxidative addition of allyl carbonate 2 to
Pd(0) followed by decarboxylation would generate the π-allyl Pd
complex B which is in equilibrium with the (η -allyl) Pd species
B’. Migratory insertion from B’ would generate the
imidoylpalladium intermediate C. β-Hydride elimination would
2
afforded the ketenimine 3a in 72% NMR yield. Stirring a slurry
of the crude mixture of 3a in water in the presence of silica gel
1
6
gave the corresponding carboxamide 8a. On the other hand,
16
increasing the temperature of the above reaction mixture
gradually to 60 °C, ketenimine 3a was consumed with concurrent
formation of 4a and 5a, indicating that 3a could well be the
II
furnish ketenimine 3 and HPd L(OEt) species. The latter would,
upon reductive elimination, regenerate the Pd(0) species A. On
the other hand, C-N bond homolysis of ketenimine 3 would
afford radical pairs D and E. The radical recombination of D and
E via C-C bond formation afforded 4 and its regioisomer 5. The
fact that the products resulting from the dimerization of D and E
and the minimum impact of TEMPO on the reaction outcome
were also in line with the fact that the D and E were formed as a
caged radical pair. The reverse ene reaction of ketenimine 3 via a
six-membered transition state could account for the formation of
14
intermediate of the present reaction. Two other products 6a and
15
7
a
were also isolated (See Supporting Information). Under
standard conditions in the presence of TEMPO or BHT, the yield
of the product 4a was not significantly affected, and products
resulting from the radical recombination with nitroxyl radical
were not detected.
17
minor products 6 and 7.
Conclusion
In conclusion, we developed a novel palladium-catalyzed 1,1-
carbocyanation of allyl carbonate 2 by α,α-disubstituted α-
isocyanoacetate 1. Formation of ketenimine 3 followed by
homolysis of the C-N bond and recombination of the resulting
caged radical pair was proposed to account for the formation of
the β-cyano-γ,δ-unsaturated ester 4.
Scheme 4. Control experiments.
Scheme
5.
Mechanistic
hypothesis.
PE:EtOAc 10:1) to afford the products as a mixture of 4 and 5
(
yellow oil). Compound 4 can be isolated by multiple elution on
3
.
Experimental section
preparative TLC (eluent: PE:EtOAc 50:1).
General procedure for the synthesis of 4
4
2
.1. Ethyl (E)-2-(1-cyano-3-phenylallyl)-2,3-dihydro-1H-indene-
-carboxylate (4a)
In a dry sealed tube was added the allyl carbonate 2 (0.1 mmol)
and the isocyanide 1 (0.11 mmol) in dry DCE (1 mL) and the
reaction mixture was stirred for 1 min before the addition of
Pd(PPh ) (10 mol%). The reaction mixture was allowed to stir at
1
9.6 mg, 60% yield (from (E)-ethyl(3-phenylallyl) carbonate
and ethyl 2-isocyano-2,3-dihydro-1H-indene-2-carboxylate),
colorless oil. H NMR (400 MHz, CDCl ) δ 7.34 - 7.24 (m, 3H),
7
7
3.67 (d, J = 16.8 Hz, 1H), 3.63 (d, J = 16.7 Hz, 1H), 3.32 (d, J =
1
1
3
4
3
5
5 °C until complete consumption of the allyl carbonate (about 1
.23 - 7.17 (m, 6H), 6.73 (d, J = 15.7 Hz, 1H), 5.95 (dd, J = 15.7,
.3 Hz, 1H), 4.32 - 4.19 (m, 2H), 3.92 (dd, J = 7.2, 1.2 Hz, 1H),
hour). Then, the reaction was cooled down to room temperature
and the solvent was evaporated under reduced pressure. The
residue was purified by flash column chromatography (eluent:
1
3
6.6, 1H), 3.28 (d, J = 16.8, 1H), 1.28 (t, J = 7.2 Hz, 3H).
C

4
Tetrahedron
.6, MA
NMR (100 MHz, CDCl ) δ 173.6, 140.0, 139
A
.9
C
5,
C
13
E
6.
P
1,
T
13
E
5
D
M
N
Hz
U
, C
S
D
C
C
R
l )IP
δ 7.24 - 7.20 (m, 4H), 6.86 - 6.82 (m, 2H), 6.74 -
T
3
3
1
4
28.8, 128.6, 127.4, 126.8, 124.5, 119.6, 118.4, 62.1, 56.3, 42.0,
0.9, 40.9, 14.3. IR υ (cm ): 2934 (br), 2357 (w), 2340 (w), 1729
6.70 (m, 2H), 5.95 (dd, J = 15.6, 8.4 Hz, 1H), 4.29 - 4.24 (m, 2H),
3.94 (dd, J = 7.5, 1.4 Hz, 1H), 3.81 (s, 3H), 3.65 (d, J = 16.8 Hz,
1H), 3.60 (d, J = 16.8 Hz, 1H), 3.28 (d, J = 16.8 Hz, 2H), 3.26 (d,
-
1
(s), 1487 (w), 1461 (w), 1448 (w), 1302 (w), 1259 (w), 1201 (s),
13
1
095 (w), 1073 (w), 1048 (w), 967 (m), 744 (s), 693 (m). HRMS
J = 16.4 Hz, 2H), 1.31 (t, J = 7.2 Hz, 3H). C NMR (100 MHz,
CDCl ) δ 173.6, 159.9, 140.0, 140.0, 137.0, 136.0, 129.8, 127.4,
+
+
(APPI) calcd for C H NO [M+H ] 332.1645; found 332.1637.
22
22
2
3
1
4
1
24.5, 124.5, 119.9, 119.4, 118.4, 114.4, 112.0, 62.1, 56.3, 55.4,
2.0, 41.0, 40.9, 14.3. IR υ (cm ): 2933 (w), 2023 (w), 1732 (s),
599 (m), 1580 (m), 1488 (m), 1458 (m), 1434 (m), 1367 (w),
4
.2.
Ethyl
(E)-2-(1-cyano-3-(o-tolyl)allyl)-2,3-dihydro-1H-
-1
indene-2-carboxylate (4b)
1
5.9 mg, 46 % yield (from (E)-ethyl (3-(o-tolyl)allyl)
1292 (m), 1264 (s), 1200 (m), 1158 (m), 1169 (m), 1097 (w),
carbonate and ethyl 2-isocyano-2,3-dihydro-1H-indene-2-
1046 (m), 969 (m), 864 (w), 799 (w), 778 (m), 759 (m), 749 (m),
1
+
carboxylate), colorless oil. H NMR (400 MHz, CDCl ) δ 7.20 (s,
690 (w), 680 (w), 654 (w). HRMS (ESI) calcd for C23
[M+Na ] 384.1570; found 384.1577.
H23NO
3
Na
3
+
4
1
3
H), 7.18 - 7.07 (m, 3H), 6.97 (d, J = 7.6 Hz, 1H), 6.93 (d, J =
5.6 Hz, 1H), 5.81 (dd, J = 15.6, 7.4 Hz, 1H), 4.31 - 4.18 (m, 2H),
.94 (dd, J = 7.4, 1.3 Hz, 1H), 3.65 (d, J = 16.8 Hz, 1H), 3.58 (d,
4
1
.6. Ethyl (E)-2-(1-cyano-3-(4-methoxyphenyl)allyl)-2,3-dihydro-
H-indene-2-carboxylate (4f)
J = 16.4 Hz, 1H) 3.28 (d, J = 16.4 Hz, 1H), 3.24 (d, J = 16.8 Hz,
13
1
H), 2.31 (s, 3H), 1.29 (t, J = 7.1 Hz, 3H). C NMR (100 MHz,
21.2 mg, 59% yield
(from
(E)-ethyl
(3-(4-
CDCl ) δ 173.6, 140.1, 140.0, 135.9, 135.0, 134.3, 130.4, 128.5,
methoxyphenyl)allyl) carbonate and ethyl 2-isocyano-2,3-
dihydro-1H-indene-2-carboxylate), yellow oil. H NMR (400
3
1
1
4
27.4, 126.3, 126.3, 124.5, 121.0, 118.5, 62.1, 56.2, 42.3, 41.1,
0.8, 19.9, 14.3. IR υ (cm ): 2978 (br), 2358 (m), 2343 (m), 1730
-
1
MHz, CDCl ) δ 7.19 (s, 4H), 7.15 (d, J = 8.7 Hz, 2H), 6.82 (d, J
3
(
9
s), 1484 (w), 1460 (w), 1303 (w), 1258 (w), 1203 (m), 1048 (w),
= 8.7 Hz, 2H), 6.65 (d, J = 15.7 Hz, 1H), 5.80 (dd, J = 15.6, 8.4
Hz, 1H), 4.26 - 4.20 (m, 2H), 3.88 (dd, J = 7.5, 1.4 Hz, 1H), 3.80
(s, 3H), 3.61 (d, J = 16.4 Hz, 1H), 3.57 (d, J = 16.0 Hz, 1H), 3.25
67 (w), 744 (m), 636 (m), 628 (m), 615 (s). HRMS (ESI) calcd
+
+
for C H NO Na [M+Na ] 368.1621; found 368.1626.
23
23
2
(
d, J = 16.4 Hz, 1H), 3.24 (d, J = 16.4 Hz, 1H), 1.28 (t, J = 7.2
4
1
.3. Ethyl (E)-2-(1-cyano-3-(p-tolyl)but-2-en-1-yl)-2,3-dihydro-
H-indene-2-carboxylate (4c)
13
Hz, 3H). C NMR (100 MHz, CDCl ) δ 173.7, 160.0, 140.1,
1
3
40.0, 135.6, 128.4, 128.1, 127.3, 124.5, 118.6, 117.2, 114.2,
-1
2
2.0 mg, 61% yield (from (E)-ethyl (3-(p-tolyl)but-2-en-1-yl)
114.2, 62.0, 56.4, 55.5, 42.1, 40.9, 14.3. IR υ (cm ): 2938 (br),
2363 (w), 2335 (w), 1730 (s), 1606 (m), 1511 (s), 1250 (s), 1176
(s), 1199 (m), 1302 (m), 1034 (m), 969 (m), 848 (w), 745 (m),
666 (w), 776 (w), 1094 (w), 1113 (w), 1367 (w), 1441 (w), 1462
(m), 1486 (w). HRMS (ESI) calcd for C23
362.1751; found 362.1758.
carbonate and ethyl 1 2-isocyano-2,3-dihydro-1H-indene-2-
carboxylate), yellow oil. H NMR (400 MHz, CDCl ) δ 7.21 (s,
3
4
4
3
1
7
1
1
H), 7.12-7.05 (m, 4H), 5.56 (dq, J = 9.9, 1.6 Hz, 1H), 4.28 -
.18 (m, 2H), 4.00 (d, J = 9.9 Hz, 1H), 3.60 (d, J = 16.5 Hz, 1H),
.59 (d, J = 16.0 Hz, 1H), 3.25 (d, J = 16.0 Hz, 1H), 3.22 (d, J =
6.8 Hz, 1H), 2.33 (s, 3H), 2.03 (d, J = 1.6 Hz, 3H), 1.27 (t, J =
+
+
H24NO
[M+H ]
3
13
4.7. Ethyl (E)-2-(3-(benzo[d][1,3]dioxol-5-yl)-1-cyanoallyl)-2,3-
dihydro-1H-indene-2-carboxylate (4g)
.2 Hz, 3H). C NMR (100 MHz, CDCl ) δ 173.7, 142.5, 140.2,
3
40.0, 139.3, 138.0, 129.2, 127.4, 127.3, 126.0, 124.7, 124.5,
19.0, 117.3, 62.0, 56.6, 41.0, 40.7, 37.4, 21.2, 16.9, 14.3. IR υ
19.2 mg, 51% yield (from (E)-3-(benzo[d][1,3]dioxol-5-
-
1
(cm ) : 2927 (br), 2364 (m), 2341 (w), 2330 (w), 1731 (s), 1513
yl)allyl ethyl carbonate and ethyl 2-isocyano-2,3-dihydro-1H-
indene-2-carboxylate), colorless oil. H NMR (400 MHz, CDCl )
δ 7.19 (s, 4H), 6.73 (d, J = 8.4 Hz, 1H), 6.69 - 6.66 (m, 2H), 6.61
(d, J = 15.4 Hz, 1H), 5.95 (s, 2H), 5.76 (dd, J = 15.6, 8.0 Hz, 1H),
1
(w), 1461 (m), 1305 (w), 1259 (m), 1196 (s), 1047 (w), 1023 (w),
3
+
8
14 (m), 742 (m), 652 (m). HRMS (ESI) calcd for C H NO Na
24
25
2
+
[M+Na ] 382.1778; found 382.1768.
4
1
3
.27 - 4.19 (m, 2H), 3.88 (dd, J = 7.3, 1.2 Hz, 1H), 3.61 (d, J =
7.6 Hz, 1H), 3.56 (d, J = 17.2 Hz, 1H), 3.24 (d, J = 16.4, 1H),
.22 (d, J = 16.4, 1H), 1.28 (t, J = 7.1 Hz, 3H). C NMR (100
4
1
.4. Ethyl (E)-2-(1-cyano-3-(2-methoxyphenyl)allyl)-2,3-dihydro-
H-indene-2-carboxylate (4d)
13
1
9.5 mg, 54
%
yield (from (E)-ethyl (3-(2-
MHz, CDCl ) δ 173.6, 148.2, 148.1, 140.1, 140.0, 135.7, 130.0,
3
methoxyphenyl)allyl) carbonate and ethyl 2-isocyano-2,3-
dihydro-1H-indene-2-carboxylate), colorless oil. H NMR (400
127.4, 124.5, 121.8, 118.5, 117.7, 108.5, 106.0, 101.4, 62.0, 56.3,
1
-1
42.0, 41.0, 40.9, 14.3. IR υ (cm ): 3031 (m), 2340 (m), 2162 (s),
MHz, CDCl ) δ 7.26 - 7.17 (m, 5H), 7.07 (dd, J = 7.6, 1.7 Hz,
2153 (m), 1802 (m), 1729 (s), 1504 (s), 1489 (s), 1446 (s), 1253
(s), 1204 (s), 1040 (s), 971 (s), 962 (m), 938 (s), 929 (s), 808 (s),
799 (m), 776 (s), 745 (s), 725 (s), 715 (m), 695 (s), 671 (m), 657
3
1
H), 7.00 (d, J = 15.8 Hz, 1H), 6.87 (d, J = 8.0 Hz, 1H), 6.85 (d,
J = 8.4 Hz, 1H), 5.97 (dd, J = 15.8, 7.7 Hz, 1H), 4.27 - 4.21 (m,
+
+
2
1
=
H), 3.91 (dd, J = 7.7, 1.3 Hz, 1H), 3.81 (s, 3H), 3.62 (d, J = 16.8,
(s). HRMS (ESI) calcd for C23
376.1556.
H22NO [M+H ] 376.1543 ; found
4
H), 3.57 (d, J = 16.8, 1H), 3.28 (d, J = 16.8 Hz, 1H), 3.25 (d, J
13
16.4 Hz, 1H),1.29 (t, J = 7.1 Hz, 3H). C NMR (100 MHz,
4
1
.8. Ethyl (E)-2-(1-cyano-3-(naphthalen-2-yl)allyl)-2,3-dihydro-
H-indene-2-carboxylate (4h)
CDCl ) δ 173.7, 157.0, 140.2, 140.1, 131.5, 129.7, 127.5, 127.3,
3
1
5
2
1
1
8
27.3, 124.7, 124.5, 124.5, 120.7, 120.0, 118.7, 110.9, 62.0, 56.4,
-1
5.5, 42.5, 40.9, 40.8, 14.3. IR υ (cm ): 2942 (br), 2358 (w),
340 (w), 1730 (s), 1598 (w), 1579 (w), 1488 (m), 1462 (m),
437 (w), 1299 (m), 1202 (m), 1113 (w), 1095 (w), 1050 (m),
026 (m), 970 (m), 861 (w), 750 (s), 758 (s), 784 (w), 794 (w)+,
02 (w), 672 (w), 686 (w). HRMS (ESI) calcd for C H NO Na
16.0 mg, 42% yield (from (E)-ethyl (3-(naphthalen-2-yl)allyl)
carbonate and ethyl 2-isocyano-2,3-dihydro-1H-indene-2-
1
carboxylate), colorless oil. H NMR (400 MHz, CDCl ) δ 7.80 -
3
7.74 (m, 3H), 7.58 (s, 1H), 7.51 - 7.42 (m, 2H), 7.34 (dd, J = 8.6,
1.8 Hz, 1H), 7.20 (s, 4H), 6.88 (d, J = 15.7 Hz, 1H), 6.05 (dd, J =
16.0, 7.6 Hz, 1H), 4.30 - 4.22 (m, 2H), 3.98 (dd, J = 7.3, 1.4 Hz,
23
23
3
+
[M+Na ] 384.1570; found 384.1580.
1
H), 3.66 (d, J = 16.4 Hz, 1H), 3.60 (d, J = 16.8 Hz, 1H), 3.30 (d,
4
1
.5. Ethyl (E)-2-(1-cyano-3-(3-methoxyphenyl)allyl)-2,3-dihydro-
H-indene-2-carboxylate (4e)
J = 16.4 Hz, 1H), 3.27 (d, J = 16.4 Hz, 1H), 1.29 (t, J = 7.1 Hz,
3
13
H). C NMR (100 MHz, CDCl ) δ 173.7, 140.1, 136.1, 133.5,
3
1
6.2
mg,
45%
yield
(from
(E)-ethyl
(3-(3-
133.4, 133.0, 128.5, 128.3, 127.8, 127.4, 127.2, 126.6, 126.5,
124.5, 124.5, 123.5, 119.9, 118.5, 62.1, 56.4, 42.2, 41.1, 40.9,
14.3. IR υ (cm ): 3239 (m), 2361 (m), 2314 (br), 2154 (m), 2091
methoxyphenyl)allyl) carbonate and ethyl 2-isocyano-2,3-
dihydro-1H-indene-2-carboxylate), colorless oil. H NMR (400
1
-1

5
(
1
7
w), 2042 (w), 2022 (s), 1967 (m), 1767 (m), 1
A
72
C
8 (
C
s)
E
, 1
P
29
T
9
E
(m
D
), MA(m
N
),
U
12
S
6
C
6
R
(m
I
)
P
, 7
T
18 (s), 965 (m), 808 (w), 1013 (m). HRMS
+ +
271 (m), 1206 (br), 887 (m), 843 (m), 783 (s), 765 (s), 743 (s),
(ESI) calcd for C H NO Na [M+Na ] 292.1308; found
17
19
2
+
+
11 (s). HRMS (ESI) calcd for C H NO [M+H ] 382.1802 ;
292.1323.
26
24
2
found 382.1804.
4
.13.
Ethyl
(E)-1-(1-cyano-3-phenylallyl)cyclohexane-1-
4
1
.9. Ethyl (E)-2-(3-(4-chlorophenyl)-1-cyanoallyl)-2,3-dihydro-
H-indene-2-carboxylate (4i)
carboxylate (4m)
1
7.4 mg, 59% yield (from (E)-ethyl(3-phenylallyl) carbonate
1
7.1 mg, 47% yield (from (E)-3-(4-chlorophenyl)allyl ethyl
and ethyl 1-isocyanocyclohexane-1-carboxylate), colorless oil.
1
carbonate and ethyl 2-isocyano-2,3-dihydro-1H-indene-2-
carboxylate), colorless oil. H NMR (400 MHz, CDCl ) δ 7.25 (d,
J = 8.0 Hz, 2H), 7.19 (s, 4H), 7.09 (d, J = 8.4 Hz, 2H), 6.67 (d, J
15.7 Hz, 1H), 5.90 (dd, J = 15.7, 7.2 Hz, 1H), 4.27 - 4.21 (m,
H NMR (400 MHz, CDCl ) δ 7.36 - 7.27 (m, 5H), 6.69 (d, J =
3
1
15.8 Hz, 1H), 5.98 (dd, J = 15.8, 7.4 Hz, 1H), 4.20 (q, J = 7.1 Hz,
2H), 3.64 (d, J = 7.4 Hz, 1H), 2.22 (d, J = 9.4 Hz, 2H), 1.75 -
3
13
=
1.61 (m, 4H), 1.53 - 1.40 (m, 4H), 1.27 (t, J = 7.0 Hz, 3H). C
2
3
1
H), 3.91 (dd, J = 7.2, 0.8 Hz, 1H), 3.63 (d, J = 16.8 Hz, 1H),
.57 (d, J = 16.4 Hz, 1H), 3.24 (d, J = 16.4 Hz, 1H), 3.22 (d, J =
6.4 Hz, 1H), 1.28 (t, J = 7.1 Hz, 3H). C NMR (100 MHz,
NMR (100 MHz, CDCl ) δ 173.2, 135.9, 135.7, 128.9, 128.6,
3
126.8, 119.2, 118.1, 61.4, 50.3, 44.5, 33.3, 30.7, 25.4, 23.3, 23.0,
13
-1
14.4. IR υ (cm ): 2940 (br), 2368 (w), 2329 (w), 2163 (m), 2152
CDCl ) δ 173.6, 140.0, 134.8, 134.5, 131.9, 128.3, 127.4, 124.5,
(m), 2065 (w), 2009 (m), 1944 (w), 1733 (s), 1448 (m), 1214 (s),
3
+
1
24.4, 122.6, 120.4, 118.2, 62.1, 56.2, 42.0, 41.1, 40.8, 14.3. IR υ
1134 (s), 739 (m), 681 (s). HRMS (ESI) calcd for C H NO Na
19
23
2
-
1
+
(cm ): 2927 (br), 2341 (m), 1730 (s), 1490 (m), 1461 (m), 1305
w), 1259 (w), 1196 (m), 1087 (w), 1047 (w), 1012 (w), 972 (w),
[M+Na ] 320.1621; found 320.1623.
(
4
.14. Ethyl (E)-1-(1-cyano-3-phenylallyl)cyclopent-3-ene-1-
8
11 (w), 745 (m), 669 (m). HRMS (APPI) calcd for
+ +
carboxylate (4n)
C H ClNO [M+H ] 366.1255; found 366.1254.
22
21
2
1
2.0 mg, 42% yield (from (E)-ethyl(3-phenylallyl) carbonate
4
1
.10. Ethyl (E)-2-(3-(4-bromophenyl)-1-cyanoallyl)-2,3-dihydro-
H-indene-2-carboxylate (4j)
and ethyl 1-isocyanocyclopent-3-ene-1-carboxylate), colorless oil.
H NMR (400 MHz, CDCl ) δ 7.38 – 7.27 (m, 5H), 6.77 (dd, J =
1
3
2
1.8 mg, 53% yield (from (E)-3-(4-bromophenyl)allyl ethyl
15.7, 1.5 Hz, 1H), 5.99 (dd, J = 15.8, 7.0 Hz, 1H), 5.66 (s, 2H),
4.24 (q, J = 7.1 Hz, 2H), 3.92 (dd, J = 7.1, 1.5 Hz, 1H), 3.02 (d, J
= 17.6 Hz, 1H), 2.97 (d, J = 17.2 Hz, 1H), 2.67 (d, J = 16.0 Hz,
carbonate and ethyl 2-isocyano-2,3-dihydro-1H-indene-2-
carboxylate), colorless oil. H NMR (400 MHz, CDCl ) δ 7.41 (d,
J = 8.4 Hz, 2H), 7.19 (s, 4H), 7.03 (d, J = 8.4 Hz, 2H), 6.66 (d, J
1
3
1
3
1H), 2.61 (d, J = 15.2 Hz, 1H), 1.30 (t, J = 7.1 Hz, 3H). C NMR
=
16.0 Hz, 1H), 5.92 (dd, J = 15.7, 7.2 Hz, 1H), 4.32-4.17 (m,
(100 MHz, CDCl ) δ 174.3, 136.0, 135.7, 135.6, 128.9, 128.6,
3
2
3
1
H), 3.91 (dd, J = 7.2, 0.8 Hz, 1H), 3.63 (d, J = 16.8 Hz, 1H),
.57 (d, J = 16.4 Hz, 1H), 3.24 (d, J = 16.8 Hz, 1H), 3.21 (d, J =
6.4 Hz, 1H), 1.28 (t, J = 7.1 Hz, 3H). C NMR (100 MHz,
128.5, 128.3, 126.8, 119.6, 118.6, 61.9, 54.3, 42.4, 42.0, 41.0,
-
1
14.3. IR υ (cm ): 2973 (br), 2359 (s), 2326 (br), 2234 (w), 2160
(m), 2147 (m), 1990 (m), 1965 (m), 1955 (m), 1841 (w), 1733 (s),
1541 (m), 1509 (m), 1451 (m), 1264 (m), 1200 (s). HRMS (ESI)
13
CDCl ) δ 173.6, 140.0, 134.7, 134.4, 134.1, 129.0, 128.0, 127.4,
1
3
+
+
24.5, 124.5, 120.3, 118.3, 62.1, 56.3, 42.0, 41.1, 40.8, 14.3. IR υ
calcd for C H NO Na [M+Na ] 304.1313; found 304.1320.
18 19 2
-
1
(
(
(
cm ): 2924 (br), 2360 (m), 2341 (w), 1732 (s), 1492 (m), 1460
m), 1445 (w), 1406 (w), 1367 (w), 1302 (m), 1256 (m), 1199
m), 1090 (m), 1042 (w), 1014 (m), 969 (w), 807 (m), 769 (w),
4
.15. Ethyl (E)-4-(1-cyano-3-phenylallyl)tetrahydro-2H-pyran-4-
carboxylate (4o)
79
+
7
42 (m), 669 (w). HRMS (APPI) calcd for C H BrNO2
6.0 mg, 20% yield (from (E)-ethyl(3-phenylallyl) carbonate
22
21
+
[M+H ] 410.0750; found 410.0748.
and
ethyl1 4-isocyanotetrahydro-2H-pyran-4-carboxylate),
colorless oil. H NMR (400 MHz, CDCl ) δ 7.38 - 7.27 (m, 5H),
3
4
.11. Ethyl (E)-1-(1-cyano-3-phenylallyl)cyclopentane-1-
6
4
.72 (dd, J = 15.7, 1.2 Hz, 1H), 5.96 (dd, J = 15.7, 7.4 Hz, 1H),
.26 (q, J = 7.1 Hz, 2H), 3.98 - 3.89 (m, 2H), 3.65 (dd, J = 7.4,
carboxylate (4k)
1
3.0 mg, 46% yield (from (E)-ethyl(3-phenylallyl) carbonate
1.3 Hz, 1H), 3.52 (dt, J = 12.0, 2.2 Hz, 1H), 3.42 (dt, J = 12.1,
and ethyl 1-isocyanocyclopentane-1-carboxylate), colorless oil.
2.1 Hz, 1H), 2.22 - 2.12 (m, 2H), 1.93 - 1.86 (m, 1H), 1.86 - 1.80
1
13
H NMR (400 MHz, CDCl ) δ 7.37 - 7.27 (m, 5H), 6.75 (dd, J =
(m, 1H), 1.29 (t, J = 7.1 Hz, 3H). C NMR (100 MHz, CDCl ) δ
3
3
1
7
1
5.8, 1.5 Hz, 1H), 6.00 (dd, J = 15.8, 6.9 Hz, 1H), 4.19 (q, J =
.2 Hz, 2H), 3.97 (dd, J = 6.9, 1.5 Hz, 1H), 2.27 - 2.14 (m, 2H),
172.3, 136.6, 135.4, 128.9, 128.9, 126.9, 118.1, 117.41, 65.2,
-
1
65.1, 61.9, 48.2, 44.4, 32.8, 31.0, 14.4. IR υ (cm ): 2959 (br),
2359 (w), 2341 (w), 2164 (s), 2153 (m), 2028 (w), 1967 (w),
1875 (w), 1804 (w), 1730 (s), 1216 (m), 1200 (m), 1031 (w),
1013 (w), 759 (s), 732 (m), 723 (m), 687 (m). HRMS (ESI) calcd
13
.90 (m, 1H), 1.85 - 1.68 (m, 5H), 1.28 (t, J = 7.2 Hz, 3H).
C
NMR (100 MHz, CDCl ) δ 174.8, 135.7, 135.6, 128.9, 128.6,
1
3
26.8, 120.4, 119.0, 61.6, 56.1, 42.4, 36.3, 33.5, 26.0, 25.8, 14.3.
-1
+
+
IR υ (cm ): 2959 (br), 2023 (m), 1448 (m), 1183 (br), 1032 (m),
69 (m), 756 (s), 696 (m), 667 (m), 1727 (s). HRMS (ESI) calcd
for C H NO Na [M+Na ] 322.1414; found 322.1417.
18 21 3
9
+
+
for C H NO Na [M+Na ] 306.1465; found 306.1475.
Acknowledgments
18
21
2
4
.12.
Ethyl
(E)-1-(1-cyano-3-phenylallyl)cyclobutane-1-
Financial supports from Swiss National Science Foundation
N° SNSF 20020-155973), EPFL (Switzerland) are gratefully
carboxylate (4l)
(
1
0.0 mg, 34% yield (from (E)-ethyl(3-phenylallyl) carbonate
acknowledged. We thank Dr. F.-T. Farzaneh and Dr. R.
Scopelliti for X-ray crystallographic analysis of 4a.
1
and ethyl 1-isocyanocyclobutane-1-carboxylate), colorless oil. H
NMR (400 MHz, CDCl ) δ 7.38 - 7.27 (m, 5H), 6.78 (d, J = 15.8
Hz, 1H), 5.98 (dd, J = 15.8, 6.8 Hz, 1H), 4.23 (q, J = 7.1 Hz, 2H),
3
Dedicated with respect to Professor Léon Ghosez for his great
contribution to the field of organic chemistry.
3
2
.95 (d, J = 6.7 Hz, 1H), 2.59 - 2.45 (m, 2H), 2.38 - 2.22 (m, 2H),
.12 - 2.00 (m, 2H), 1.29 (t, J = 7.1 Hz, 3H). C NMR (100 MHz,
13
References and notes
CDCl ) δ 173.7, 135.7, 135.6, 128.9, 128.6, 126.8, 119.1, 118.5,
3
-
1
6
2
1
1.6, 49.3, 41.5, 29.4, 27.1, 15.6, 14.4. IR υ (cm ): 2952 (br),
370 (m), 2177 (m), 2017 (m), 1970 (m), 2189 (m), 1730 (s),
721 (s), 1650 (w), 1558 (w), 1542 (w), 1457 (m), 1206 (s), 1254
1
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1
3
CCDC 1843030 (4a) contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge
Crystallographic
Data
Centre
via
www.
ccdc.cam.ac.uk/data_request/cif.
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1
1
4
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