Unexpected reactivity of 3-(phenylethynyl)-1H-indenes towards nucleophiles: Noncatalytic addition to triple bond with or without double bond migration

Article abstract of DOI:10.1055/s-2007-965957

When studying the chemical properties of (3-phenylethynyl)-1H-indenes, a new reaction was discovered, namely, nucleophilic addition to conjugated enynes accompanied in some cases by migration. The reaction takes place under mild conditions and is not cata

Full text of DOI:10.1055/s-2007-965957

1038
PAPER
Unexpected Reactivity of 3-(Phenylethynyl)-1H-indenes towards
Nucleophiles: Noncatalytic Addition to Triple Bond with or without
Double Bond Migration
3
-(Phenylethy
.
nyl)-(1
H
)-ind
V
enes:
N
ucleophili
.
c
A
ddition Ivchenko,*a I. E. Nifant’ev,a Yu. N. Luzikov,a S. G. Mkoyanb
a
M. V. Lomonosov Moscow State University, Department of Chemistry, Leninskie Gory, Moscow, 119992, Russian Federation
Fax +7(495)9394523; E-mail: inpv@org.chem.msu.ru
Institute of Problem of Chemical Physics of the Russian Academy of Science, 1 Akademika Semenova Prospect, Chernogolovka,
Moscow Region, 142432, Russian Federation
b
Received 12 October 2006; revised 18 January 2007
This fact is surprising, because, to our knowledge, all 3-
substituted indenes known to date are able to form lithium
salts which are quite stable under inert atmosphere.
Abstract: When studying the chemical properties of (3-phenyl-
ethynyl)-1H-indenes, a new reaction was discovered, namely, nu-
cleophilic addition to conjugated enynes accompanied in some
cases by migration. The reaction takes place under mild conditions
and is not catalyzed by transition metal complexes. A putative reac-
tion mechanism via an allene intermediate is discussed.
Therefore, we resorted to a substantially milder method
for the synthesis of fulvenes,7 which involves the reaction
of 1 with acetone in the presence of pyrrolidine. This did
not give the desired fulvene either; however, compound 3,
which can be regarded as resulting from the addition of
pyrrolidine to the indene 1 triple bond followed by
isomerization, was isolated quantitatively (Scheme 2).
Key words: alkynes, allenes, enynes, nucleophilic additions, rear-
rangements
Substituted indenes are widely used both in organic syn-
thesis and as ligands for the preparation of organometallic
compounds.1 Thousands of alkyl-,2 alkenyl-,3 and
arylindenes4 and diverse indenes containing heteroat-
om(s) in the side chain3,5 have now been prepared. How-
ever, alkynylindenes remain barely described,6 which
accounts for our interest in these compounds.
Ph
Ph
2
NH
During our work on the synthesis and study of acetylenyl-
indenes, we prepared (3-phenylethynyl)-1H-indene (1)
and attempted to convert it into the corresponding dimeth-
ylfulvene 2. First, we investigated the two most popular
approaches to this synthesis: the transformation of indene
into the lithium salt followed by treatment with acetone
and the base-catalyzed reaction of indene with acetone
(Scheme 1).
+
O
Ph
1
N
3
Scheme 2
Ph
Ph
Ph
The molecular structure of 3 was determined by X-ray dif-
fraction (Figure 1). The molecule has an E-configuration;
no significant deviations of the bond lengths and angles
from the normal values were detected.
O
BuLi
Et2O
_
NaOH, THF
Li+
To the best of our knowledge, no data on the addition of
secondary amines to acetylenes and enynes not catalyzed
by transition metals has been reported previously; hence,
the formation of 3 is a new outcome in this area. This ar-
ticle describes the study of the reaction of (3-phenylethy-
nyl)-1H-indene (1) and some of its analogues with amines
and other nucleophilic reagents in order to determine the
synthetic potential and to elucidate the most likely mech-
anism of this reaction.
2
1
1a
Scheme 1
Unexpectedly, neither of these reactions gave the desired
product; moreover, it was impossible to isolate the lithium
derivative 1a (Scheme 1). The reaction of 1 with n-butyl-
lithium gave unidentified products, presumably polymers.
We prepared 3-(phenylethynyl)-1H-indene (1) by the re-
action of PhC≡CMgBr with indan-1-one followed by hy-
drolysis and dehydration. Substituted indanones, 2-
methylindan-1-one, 4,7-dimethylindan-1-one, and 2,4,7-
SYNTHESIS 2007, No. 7, pp 1038–1046
Advanced online publication: 28.02.2007
DOI: 10.1055/s-2007-965957; Art ID: T15206SS
© Georg Thieme Verlag Stuttgart · New York
x
x
.
x
x
.2
0
0
7

PAPER
3-(Phenylethynyl)-1H-indenes Nucleophilic Addition
1039
Table 2 Addition of Nucleophiles to 3-(Phenylethynyl)-1H-indene
(1)
Ph
Ph
Nu
NuH of Nu–/NuH
1
Product
Nu
Yield (%)
93
3
N
7
8
NMe2
93
88
96
94
Figure 1 Molecular structure of 3
OEt
trimethylindan-1-one, react similarly (Table 1). The new-
ly prepared 3-(phenylethynyl)-1H-indenes 1, 4, 5, and 6
are quite air-stable crystalline materials.
9
SCMe3
P(O)(OEt)2
10
Table 1 3-(Phenylethynyl)-1H-indenes 1, 4–6
Table 3 Reaction of t-BuNH2 and Piperidine with 3-(Phenylethy-
nyl)-1H-indene (1)
Ph
R1
R1
O
Ph
R
R
1. Ph
2. H+, Et2O
MgBr
R
Ph
N
N
R'
R'
N
R2
R2
R'
Ph
RR'NH
1
+
+
R1
R1
C
B
A
Product
R1
R2
H
Yield (%)
R
R¢
Product type A; Product type B; Product type C;
1
4
5
6
H
57
67
71
85
Yield (%)
Yield (%)
Yield (%)
H
Me
H
t-Bu
H
11; 12
12; 69
0
Me
Me
-(CH2)4-
13; 10
14; 15
15; 59
Me
venes similar to A and B would arise upon the reaction of
indenes 4–6 with nucleophiles. We studied the reactions
of 4–6 with a standard set of N-, O-, S- and P-nucleophiles
and found that only vinylindene products of type C are
formed in each case. Yields are generally high (Scheme 3,
Table 4). Thus, the lack of possibility for the formation of
type A and B fulvenes does not preclude the reaction giv-
ing products of type C.
The reaction of indene 1 with an equivalent amount of
pyrrolidine gives adduct 3 in a nearly quantitative yield.
Compound 1 was also found to react with dimethylamine,
sodium ethoxide in ethanol, t-BuSNa/THF, and
(EtO)2PONa/THF to give products 7–10 with structures
similar to 3 (Table 2). All of the reactions give products in
high yields (88–94%). In the cases of potassium tert-butyl
thiolate and sodium diethyl phosphonate high product
yields were attained only upon the presence of substantial
amounts of tert-butyl mercaptan and diethyl phosphite.
Ph
Nu
R1
R1
However, the reaction of 1 with amines is not always ste-
reo- and regioselective giving only one product, as in the
case of 3 and 7. Some other amines react to give adduct
mixtures. For example, tert-butylamine forms a mixture
of two isomeric fulvenes 11 and 12, and piperidine yields
three reaction products, two of which are isomeric ful-
venes 13 and 14, while the third one is vinylindene 15
(Table 3). Arylamines and hydrazines do not react with 1.
Ph
NuH of Nu–/NuH
R2
R2
R1
C
R1
Scheme 3
Considering the experimental data, the reaction mecha-
nism shown in Scheme 4 appears most likely. For simplic-
ity, the reaction of 1 with pyrrolidine is presented. In the
first stage, 3-(phenylethynyl)-1H-indene (1) partially
Substituents in positions 2 and/or 4 (7) of the indenyl ring
are known to hamper the formation of substituted ful-
venes.8 Therefore, it was pertinent to find out whether ful-
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

1040
P. V. Ivchenko et al.
PAPER
Table 4 Interaction of Substituted 3-(Phenylethynyl)-1H-indenes
Ph
with Nucleophilesa
Ph
N
N
Nucleophilic reagent Solvent Product, yield (%)
4
5
6
A, >99%
C
NHMe2
NHEt2
Et2O
Et2O
Et2O
Et2O
16, 95
19, 93
22, 81
25, 81
17, 98
20, 89
23, 76
26, 92
18, 82
21, 85
24, 90
27, 98
+
NH2
–
n-BuNH2
Ph
Ph
N
N
NH
NH
_
Ph
H
Et2O
Et2O
28, 95
31, 85
29, 94
32, 98
30, 92
33, 96
D2
D1
C
NH
1
NH
O
NH
N
N
43
–
EtONa/EtOH
EtOH
THF
THF
34, 95
37, 86
40, 81
35, 89
38, 90
41, 96
36, 90
39, 71
42, 84
Ph
Ph
_
t-BuSNa/t-BuSH
D4
D3
(EtO)2PONa/
(EtO)2POH
+
NH2
a Reactions conducted at 20 °C.
N
N
Ph
Ph
isomerizes into allene 43. This process is highly probable
in view of the fact that the reactions of 1 with pyrrolidine
or other nucleophiles take place in basic media. Com-
pound 43 reacts with a pyrrole molecule to give anion D.
Anion D can be represented as two resonance structures,
D1 and D2, illustrating two ways of the protonation of D
leading both fulvenes and vinylindenes.9
B
C
Scheme 4
Ph
Ph
Ph
Note that the attack by the nucleophile on fulvene 43
should occur stereoselectively as the anti-addition with
respect to the phenyl group in order to minimize the steric
strain in the transition state. Hence isomers C of com-
pounds 16–42 are formed. It is also noteworthy that the at-
tack by the nucleophile on allene 43 should be
immediately followed by rotation of the PhHC= group
about the C–C bond giving rise to anion D (Scheme 4). In
this rotation, the pyrrolidine group may move either to-
ward the indene six-membered ring or in the opposite di-
rection. The latter option is more likely, as in this case, the
steric repulsion between the pyrrolidine group and the in-
denyl fragment would be minimal. Hence, the reaction of
1 with pyrrolidine gives E-isomer of 3 rather than Z-iso-
mer. Then the protonation of conformer D3-4 appears to
be the obvious route to the Z-isomer (Scheme 4).
44
45
46
Figure 2
When studying the chemical properties of (3-phenylethy-
nyl)-1H-indene (1), a new reaction was discovered –
nucleophilic addition to conjugated enynes under mild
conditions accompanied by migration of the multiple
bonds locations. It was shown that the most probable re-
action mechanism includes a 2,4-enyne to 1,3,4-triene re-
arrangement. The high synthetic potential of the reaction
was demonstrated by the preparation of a number of func-
tionalized indenes.
If our assumption concerning the mechanism is valid,
compounds structurally related to 3-(phenylethynyl)-1H-
indene (1) but incapable of isomerization to allene would
not react with nucleophiles to give addition products. To
verify this hypothesis, we prepared compounds 44–46
(Figure 2) and allowed them to react with pyrrolidine. In
none of the cases, did the reaction occur, not even under
drastic conditions.
All manipulations were carried out under argon. The solvents were
commercially available, purified by conventional means and dis-
tilled immediately prior to use. 2-Methylindanone,10 4,7-dimethyl-
indanone,11
2,4,7-trimethylindanone,11
and
3,3-dimethyl-
indanone12 were prepared according to published procedures.
1H NMR and 13C NMR spectra were recorded at 20 °C on a Varian
XR-400 spectrometer. The assignments in braces in the NMR data
represent collective allotments for the preceding peaks.
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

PAPER
3-(Phenylethynyl)-1H-indenes Nucleophilic Addition
1041
3-(Phenylethynyl)-1H-indene (1); Typical Procedure
13C{1H} NMR (CDCl3): d = 151.4, 141.0, 140.3, 129.8, 128.4,
123.9, 121.4 (C=), 130.9, 129.0, 128.2, 127.8, 125.5 (=CH), 94.8,
86.1(C≡), 41.4 (CH2), 18.5, 18.1, 15.9 (CH3).
A solution of EtBr (12.7 mL, 0.17 mol) in Et2O (200 mL) was added
dropwise to Mg turnings (4.13 g, 0.17 mol). After stirring for 1 h of,
phenylacetylene (20 mL, 0.18 mol) was added within 30 min at r.t.
The resulting mixture was stirred for 1 h, refluxed for 2 h, cooled to
0 °C, and indan-1-one (15 g, 113 mmol) in Et2O (50 mL) was added
dropwise. After stirring overnight at r.t., the mixture was cooled to
0 °C, and 10% aq NH4Cl was added until transparency. The pale
yellow organic layer was separated, and the aqueous phase was ex-
tracted with Et2O (4 × 50 mL). The combined organic phase was
dried (MgSO4) and evaporated at 80 °C/20 Torr. The residue was
dissolved in Et2O (150 mL), PTSA (0.2 g) was added, and the mix-
ture was refluxed for 1 h. The resulting red-brown solution was
cooled, washed with H2O (200 mL) and aq Na2CO3 (5%, 20 mL),
dried (MgSO4), evaporated, and dried in vacuo. Hexane (40 mL)
was added, and the mixture was refluxed until most of the brown oil
had dissolved. The resulting clear solution was separated and
cooled to 2 °C. After 1 d, the precipitate was filtered off, washed
with pentane, and dried in vacuo, giving 13.9 g (57%) of the prod-
uct; orange powder.
Anal. Calcd for C20H18 (258.36): C, 92.98; H, 7.02. Found: C,
92.90; H, 7.10.
1-[(1E)-1-(1H-Inden-1-ylidene)-2-phenylethyl]pyrrolidine (3)
Pyrrolidine (0.41 mL, 7 mmol) was added with stirring to a solution
of 1 (1.08 g, 5 mmol) in Et2O (10 mL). The mixture became green-
brown. After stirring for 20 min, 10% aq NH4Cl (20 mL) and Et2O
(20 mL) were added. The organic phase was separated, washed with
aq NH4Cl (10%, 5 mL), dried (MgSO4), and evaporated under re-
duced pressure. The residue (green-brown solid) was dried in vacuo
to give 1.34 g (93%) of product.
1H NMR (CDCl3): d = 7.58 (d, 3J = 7.6 Hz, 1 H), 7.51 (d, 3J = 7.8
Hz, 1 H), 7.43–7.27 (m, 5 H), 7.28 (d, 3J = 5.2 Hz, 1 H), 7.16 (dd,
3
3J = 7.6, 6.8 Hz, 1 H), 7.03 (dd, J = 7.8, 6.8 Hz, 1 H), 6.84 (d,
3J = 5.2 Hz, 1 H) {Harom, CH=}, 4.52 (br s, 2 H, CH2), 3.73 (m, 4 H,
NCH2), 1.90 (m, 4 H, NCH2CH2).
13C{1H} NMR (CDCl3): d = 153.2, 139.5, 136.4, 135.6, 113.2 (C=),
128.9, 127.9, 126.5, 125.9, 121.8, 121.7, 120.5, 120.1, 117.9 (CH=),
51.8 (NCH2CH2), 39.2 (CH2), 25.1 (NCH3CH2).
1H NMR (CDCl3): d = 7.72 (d, 3J = 7.3 Hz, 1 H), 7.66 (m, 2 H), 7.55
3
3
(d, J = 7.2 Hz, 1 H), 7.46 (m, 4 H), 7.35 (t, J = 7.3 Hz, 1 H) {
H
arom}, 6.94 (t, 3J = 2.2 Hz, 1 H, CH=), 3.57 (d, 3J = 2.35 Hz, 2 H,
CH2).
Anal. Calcd for C21H21N (287.40): C, 87.76; H, 7.37. Found: C,
87.71; H, 7.44.
13C{1H} NMR (CDCl3): d = 143.6, 142.5, 126.2, 123.0 (C=), 138.1,
131.6, 128.2, 126.4, 125.4, 123.5, 120.1 (CH=), 92.7, 83.4 (C≡),
38.5 (CH2).
(1E)-1-(1H-Inden-1-ylidene)-N,N-dimethyl-2-phenylethan-
amine (7)
In the same manner as described for 3, adduct 7 (0.34 g) was ob-
tained in 85% yield by the reaction of 1 (303 mg, 1.4 mmol) with
40% aq Me2NH (0.18 mL, 1.6 mmol) in Et2O (10 mL); brown oil.
1H NMR (CDCl3): d = 7.48–7.36 (m, 6 H), 7.29–6.99 (m, 3 H), 6.93
(d, 3J = 5.2 Hz, 1 H), 6.83 (d, 3J = 5.2 Hz, 1 H) {Harom, CH=}, 4.36
(s, 2 H, CH2), 2.78 (s, 6 H, NCH3).
Anal. Calcd for C17H12 (216.28): C, 94.41; H, 5.59. Found: C,
94.35; H, 5.65.
2-Methyl-3-(phenylethynyl)-1H-indene (4)
In the same manner as described above, compound 4 (21.5 g) was
obtained in 67% yield by the reaction of PhC≡CMgBr (0.30 mol)
with 2-methylindan-1-one (20.1 g, 0.14 mol); orange crystals; mp
62 °C.
Anal. Calcd for C19H19N (261.36): C, 87.31; H, 7.33. Found: C,
87.26; H, 7.40.
1H NMR (CDCl3): d = 7.65 (m, 2 H), 7.57 (d, J = 7.4 Hz, 1 H),
3
3
7.45–7.40 (group of m, 4 H), 7.39 (d, J = 7.4 Hz, 1 H), 7.25 (t,
3J = 7.4 Hz, 1 H) {Harom}, 3.49 (s, 2,H, CH2), 2.40 (s, 3 H, CH3).
(1E)-1-(1-Ethoxy-2-phenylethylidene)-1H-indene (8)
Compound 1 (2.16 g, 10 mmol) was added to a vigorously stirred
solution of EtONa [obtained from Na (0.23 g, 10 mmol)] in EtOH
(30 mL). After 4 h, 10% aq NH4Cl (20 mL) and Et2O (100 mL) were
added. The organic phase was separated, washed with aq NH4Cl
(2 × 20 mL) and H2O (2 × 20 mL), and dried (MgSO4). The solvents
were removed, and the residue was purified by column chromatog-
raphy (hexane–CH2Cl2, 1:1; Rf = 0.5) to afford 2.18 g (88%) of the
product; viscous red oil.
1H NMR (CDCl3): d = 8.21 (m, 1 H), 7.45–7.25 (group of m, 8 H)
{Harom}, 6.84, 6.82 (AB, 3J = 5.5 Hz, 2 H, CH=), 4.22 (s, 2 H, CH2),
4.17 (q, 3J = 7.1 Hz, 2 H, CH2), 1.45 (t, 3J = 7.1 Hz, 3 H, CH3).
13C{1H} NMR (CDCl3): d = 159.7, 142.1, 136.7, 134.3, 122.0 (C=),
128.8, 128.1, 126.9, 126.6, 125.9, 125.3, 124.3, 124.0, 120.4 (CH=),
64.0 (OCH2), 35.4 (CH2), 15.2 (CH3).
Anal. Calcd for C18H14 (230.30): C, 93.87; H, 6.13. Found: C,
93.80; H, 6.20.
4,7-Dimethyl-3-(phenylethynyl)-1H-indene (5)
In the same manner as described above, compound 5 (31.3 g) was
obtained in 71% yield by the reaction of PhC≡CMgBr (0.27 mol)
with 4,7-dimethylindan-1-one (28.8 g, 0.18 mol); yellow crystals;
mp 84 °C.
1H NMR (CDCl3): d = 7.62 (m, 2 H), 7.42 (m, 3 H), 7.09 (d, 3J = 7.8
Hz, 1 H), 7.03 (d, 3J = 7.8 Hz, 1 H) {Harom}, 6.95 (t, 3J = 2.4 Hz, 1
H, CH=), 3.41 (d, 3J = 2.4 Hz, 2 H, CH2), 2.89 (s, 3 H), 2.40 (s, 3 H)
{CH3}.
13C{1H} NMR (CDCl3): d = 142.0, 140.2, 130.4, 129.6, 126.7,
123.5 (C=), 139.5, 131.2, 129.1, 128.3, 128.2, 126.6 (=CH), 92.0,
86.7 (C≡), 37.4 (CH2), 18.6, 18.2 (CH3).
Anal. Calcd for C19H18O (262.35): C, 86.99; H, 6.92. Found: C,
86.90; H, 7.01.
Anal. Calcd for C19H16 (244.33): C, 93.40; H, 6.60. Found: C,
93.33; H, 6.47.
(1E)-1-[1-(tert-Butylsulfanyl)-2-phenylethylidene]-1H-indene
(9)
2,4,7-Trimethyl-3-(phenylethynyl)-1H-indene (6)
In the same manner as described above, compound 6 (10 g) was ob-
tained in 85% yield by the reaction of PhC≡CMgBr (72 mmol) with
2,4,7-trimethylindan-1-one (7.9 g, 45 mmol); yellow crystals; mp
88 °C.
1H NMR (CDCl3): d = 7.63 (m, 2 H), 7.41 (m, 3 H), 7.07 (d, 3J = 7.6
Hz, 1 H), 6.96 (d, J = 7.6 Hz, 1 H) {Harom, =CH}, 3.31 (s, 2 H,
tert-Butylmercaptan (1.24 mL, 11 mmol) was added to a suspension
of NaH (0.24 g, 10 mmol) in a mixture of Et2O (25 mL) and THF (3
mL). The resulting mixture was refluxed for 2 h and cooled to r.t.,
and 1 (2.16 g, 10 mmol) in Et2O (10 mL) was added dropwise. After
stirring for 4 h, the mixture was cooled, and 10% aq NH4Cl (10 mL)
was added. The organic phase was separated, dried (MgSO4), evap-
orated, and finally dried in vacuo giving a dark red oily product
(2.94 g, 96%).
3
CH2), 2.87 (s, 3 H), 2.41 (s, 3 H), 2.36 (s, 3 H) {CH3}.
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

1042
P. V. Ivchenko et al.
PAPER
1H NMR (CDCl3): d = 7.57 (m, 1 H), 7.40 (m, 2 H), 7.29–7.24 (m,
1 H), 7.20–7.16 (m, 1 H), 6.69 (t, 3J = 2.4 Hz, 1 H) {Harom, CH=},
4.52 (br s, 2 H, CH2), 1.38 [s, 9 H, C(CH3)3].
13C{1H} NMR (CDCl3): d = 144.5, 143.6, 142.9, 136.6, 129.8 (C=),
138.0, 133.7, 128.7, 127.8, 127.1, 125.7, 124.6, 123.5, 121.5 (CH=),
46.6 [C(CH3)3], 38.0 (CH2), 31.3 [C(CH3)3].
13
1H NMR (CDCl3): d = 7.70–6.95 (group of m, 8 H), 6.85 (d, 3J = 5.0
Hz, 1 H) {Harom, CH=}, 4.58 (s, 2 H, CH2), 3.70 (m, 4 H, NCH2),
1.51 (m, 6 H, CH2).
14
1H NMR (CDCl3): d = 7.70–6.95 (group of m, 8 H), 6.83 (d, 3J = 5.0
Hz, 1 H) {Harom, CH=}, 4.28 (s, 2 H, CH2), 3.52 (m, 4 H, NCH2),
1.51 (m, 6 H, CH2).
Anal. Calcd for C21H22S (306.46): C, 82.31; H, 7.24. Found: C,
82.25; H, 7.17.
Diethyl (1E)-1-(1H-Inden-1-ylidene)-2-phenylethylphos-
phonate (10)
15
1H NMR (CDCl3): d = 7.66 (d, 3J = 7.0 Hz, 1 H), 7.58 (d, 3J = 6.8
Hz, 1 H), 7.36–7.31 (m, 3 H), 7.13–7.05 (m, 4 H), 6.49 (t, 3J = 2.0
Hz, 1 H) {Harom, =CH}, 5.79 (s, 1 H, =CHPh), 3.44 (d, 3J = 2.0 Hz,
2 H, CH2), 3.09 (br s, 4 H, NCH2), 1.68 (m, 6 H, CH2).
Diethyl phosphite (0.76 mL, 5.5 mmol) was added to a suspension
of NaH (0.12 g, 5 mmol) in Et2O (20 mL). The resulting mixture
was stirred for 2 h, cooled to –20 °C, and a solution of 1 (1.08 g, 5
mmol) in Et2O (5 mL) was added. After 2 h, the mixture was treated
with 10% aq NH4Cl (20 mL). The organic phase was separated,
dried (MgSO4), evaporated, and finally dried in vacuo to give a pale
brown oily product (1.67 g, 94%).
Anal. Calcd for C22H23N (301.43): C, 87.66; H, 7.69. Found: C,
87.71; H, 7.59.
(E)-N,N-Dimethyl-1-(2-methyl-1H-inden-3-yl)-2-phenylethen-
amine (16)
In the same manner as described for 3, adduct 16 (0.34 g) was ob-
tained in 95% yield by the reaction of 4 (300 mg, 1.3 mmol) with
40% aq Me2NH (0.17 mL, 1.5 mmol) in Et2O (10 mL); brown oil.
1H NMR (CDCl3): d = 7.48 (d, 3J = 7.4 Hz, 1 H), 7.44 (d, 3J = 7.6
Hz, 1 H), 7.32 (t, 3J = 7.6 Hz, 1 H), 7.22 (t, 3J = 7.4 Hz, 1 H), 7.10–
6.91 (group of m, 5 H) {Harom}, 5.66 (s, 1 H, =CH), 3.35 (AB,
2J = 22.8 Hz, 2 H, CH2), 2.81 (s, 6 H, NCH3), 1.80 (s, 3 H, CH3).
1H NMR (CDCl3): d = 7.90 (d, 3J = 16.8 Hz, 1 H), 7.58 (d, 3J = 8.0
Hz, 1 H), 7.39 (m, 2 H), 7.28–7.15 (m, 5 H), 7.09 (d, 3J = 8.0 Hz, 1
H), 6.72 (m, 1 H) {Harom, CH=}, 4.20 (qd, J = 7.4, 2.2 Hz, 4 H,
3
OCH2CH3), 3.63 (dd, J = 5.7, 2.1 Hz, 2 H, CH2), 1.33 (t, J = 7.4
Hz, 6 H, OCH2CH3).
13C{1H} NMR (CDCl3): d = 142.4, 138.6 (d), 134.7 (d), 124.9,
123.1 (C=), 144.5 (d), 132.9, 129.8, 128.9, 127.9, 125.6, 124.6,
123.5, 120.3 (CH=), 81.8 (OCH2), 38.4 (CH2), 16.0 (CH3).
31P NMR (CDCl3): d = 15.86.
Anal. Calcd for C20H21N (275.39): C, 87.23; H, 7.69. Found: C,
87.30; H, 7.77.
Anal. Calcd for C21H23O3P (354.38): C, 71.17; H, 6.54. Found: C,
71.28; H, 6.66.
(E)-1-(4,7-Dimethyl-1H-inden-3-yl)-N,N-dimethyl-2-phenyl-
ethenamine (17)
In the same manner as described for 3, adduct 17 (0.34 g) was ob-
tained in 98% yield by the reaction of 5 (293 mg, 1.2 mmol) with
40% aq Me2NH (0.17 mL, 1.5 mmol) in Et2O (10 mL); brown oil.
Reaction of 1 with tert-Butylamine; N-[(1E)-1-(1H-Inden-1-
ylidene)-2-phenylethyl]-2-methyl-2-propanamine (11) and N-
[(1Z)-1-(1H-Inden-1-ylidene)-2-phenylethyl]-2-methyl-2-pro-
panamine (12)
In the same manner as described for 3, the adduct with tert-butyl-
amine was obtained in 81% yield (0.33 g) by the reaction of 1 (303
mg, 1.4 mmol) with tert-BuNH2 (117 mg, 1.6 mmol) in Et2O (10
mL); brown oil. A mixture of two inseparable E- and Z-isomers
(1:6) was obtained.
1H NMR (CDCl3): d = 7.24 (m, 1 H), 7.12–7.01 (m, 3 H), 6.96 (d,
3J = 7.6 Hz, 2 H), 6.89 (t, 3J = 7.2 Hz, 1 H), 6.44 (s, 1 H)
2
{Harom, =CH}, 5.57 (s, 1 H, =CHPh), 3.25 (AB, J = 24.4 Hz, 2 H,
CH2), 2.86 (s, 6 H, NCH3), 2.52 (s, 3 H), 2.43 (s, 3 H) {CH3}.
Anal. Calcd for C21H23N (289.41): C, 87.15; H, 8.01. Found: C,
87.22; H, 7.95.
11
1H NMR (CDCl3): d = 7.60 (d, 3J = 7.4 Hz, 1 H), 7.54 (d, 3J = 7.0
Hz, 1 H), 7.42–6.72 (group of m, 9 H) {Harom, CH=}, 4.52 (s, 2 H,
CH2), 1.41 [s, 9 H, C(CH3)3].
(E)-N,N-Dimethyl-2-phenyl-1-(2,4,7-trimethyl-1H-inden-3-
yl)ethenamine (18)
In the same manner as described for 3, adduct 18 (0.30 g) was ob-
tained in 82% yield by the reaction of 6 (310 mg, 1.2 mmol) with
40% aq Me2NH (0.17 mL, 1.5 mmol) in Et2O (10 mL); brown oil.
1H NMR (CDCl3): d = 7.11–6.92 (group of m, 7 H, Harom), 5.58 (br
s, 1 H, =CH), 3.26 (AB, J = 22.8 Hz, 2 H, CH2), 2.85 (s, 6 H,
12
1H NMR (CDCl3): d = 7.69 (d, 3J = 7.2 Hz, 1 H), 7.54 (d, 3J = 7.0
3
Hz, 1 H), 7.42–6.72 (group of m, 7 H), 6.83 (d, J = 5.4 Hz, 1 H),
6.62 (d, 3J = 5.4 Hz, 1 H) {Harom, CH=}, 4.37 (s, 2 H, CH2), 1.49 [s,
2
9 H, C(CH3)3].
NCH3), 2.47 (s, 3 H), 2.42 (s, 3 H), 1.90 (s, 3 H) {CH3}.
Anal. Calcd for C21H23N (289.41): C, 87.15; H, 8.01. Found: C,
87.22; H, 7.95.
13C{1H} NMR (CDCl3): d = 145.6, 143.5, 142.4, 141.4, 140.0,
135.4, 129.7, 128.6 (C=), 129.1, 127.8, 126.5, 125.2, 122.9, 102.1
(=CH), 41.4 (CH2), 39.5, 18.3, 17.7, 14.5 (CH3).
Reaction of 1 with Piperidine 1-[(1E)-1-(1H-Inden-1-ylidene)-2-
phenylethyl]piperidine (13), 1-[(1Z)-1-(1H-Inden-1-ylidene)-2-
phenylethyl]piperidine (14), and 1-[(E)-1-(1H-Inden-3-yl)-2-
phenylethenyl]piperidine (15)
In the same manner as described for 3, the adduct with piperidine
was obtained in 84% yield (0.36 g) by the reaction of 1 (303 mg, 1.4
mmol) with piperidine (136 mg, 1.6 mmol) in Et2O (10 mL); brown
oil. A mixture of three inseparable E- and Z-fulvene isomers 13, 14
and enamine 15 was obtained in the ratio of 2:3:12.
Anal. Calcd for C22H25N (303.44): C, 87.08; H, 8.30. Found: C,
87.15; H, 8.33.
(E)-N,N-Diethyl-1-(2-methyl-1H-inden-3-yl)-2-phenylethen-
amine (19)
In the same manner as described for 3, adduct 19 (0.37 g) was ob-
tained in 93% yield by the reaction of 4 (300 mg, 1.3 mmol) with
diethylamine (110 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
3
3
1H NMR (CDCl3): d = 7.50 (d, J = 7.2 Hz, 2 H), 7.34 (t, J = 7.5
3
Hz, 1 H), 7.24 (t, J = 7.5 Hz, 1 H), 7.08 (m, 2 H), 6.97 (m, 3 H)
{Harom}, 5.70 (s, 1 H, =CH), 3.35 (AB, 2J = 22.6 Hz, 2 H, CH2), 3.25
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

PAPER
3-(Phenylethynyl)-1H-indenes Nucleophilic Addition
1043
(m, 4 H, CH2CH3), 1.84 (s, 3 H, CH3), 1.21 (t, 3J = 7.2 Hz,
CH2CH3).
(E)-N-Butyl-2-phenyl-1-(2,4,7-trimethyl-1H-inden-3-yl)ethen-
amine (24)
In the same manner as described for 3, adduct 24 (0.36 g) was ob-
tained in 90% yield by the reaction of 6 (310 mg, 1.2 mmol) with n-
butylamine (110 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
Anal. Calcd for C22H25N (303.44): C, 87.08; H, 8.30. Found: C,
87.18; H, 8.38.
(E)-1-(4,7-Dimethyl-1H-inden-3-yl)-N,N-diethyl-2-phenylethen-
amine (20)
In the same manner as described for 3, adduct 20 (0.37 g) was ob-
tained in 89% yield by the reaction of 5 (293 mg, 1.2 mmol) with
diethylamine (110 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
1H NMR (CDCl3): d = 7.51 (t, 3J = 7.4 Hz, 2 H), 7.31 (t, 3J = 7.4 Hz,
1 H), 7.25–7.20 (m, 2 H), 7.09 (d, 3J = 7.4 Hz, 1 H), 6.94 (d, 3J = 7.4
Hz, 2 H) {Harom, =CH}, 3.26 (m, 2 H, NCH2), 3.11 (AB, 2J = 14.2
Hz, 2 H, CH2), 2.31 (s, 3 H), 2.25 (s, 3 H), 2.05 (s, 3 H) {CH3},
1.60–1.31 (m, 4 H, CH2CH2CH3), 0.97 (t, 3J = 6.8 Hz, 3 H,
CH2CH3).
1H NMR (CDCl3): d = 7.10–7.02 (group of m, 4 H), 6.96 (d, 3J = 7.6
Hz, 2 H), 6.89 (t, 3J = 7.3 Hz, 1 H), 6.40 (br s, 1 H), 5.54 (br s, 1 H)
Anal. Calcd for C24H29N (331.49): C, 86.96; H, 8.82. Found: C,
87.00; H, 8.90.
2
{Harom, =CH}, 3.31 (AB, J = 24.0 Hz, 2 H, CH2), 3.25 (m, 4 H,
CH2CH3), 2.50 (s, 3 H), 2.44 (s, 3 H) {CH3}, 1.17 (t, 3J = 7.0 Hz, 6
H, CH2CH3).
1-[(E)-1-(2-Methyl-1H-inden-3-yl)-2-phenylethenyl]pyrroli-
dine (25)
In the same manner as described for 3, adduct 25 (0.34 g) was ob-
tained in 81% yield by the reaction of 4 (300 mg, 1.3 mmol) with
pyrrolidine (107 mg, 1.5 mmol) in Et2O (10 mL); yellow oil.
1H NMR (CDCl3): d = 7.50 (d, 3J = 7.3 Hz, 1 H), 7.39 (d, 3J = 7.2
Hz, 1 H), 7.33 (dd, 3J = 7.2, 8.2 Hz, 1 H), 7.24 (dd, 3J = 7.3, 8.2 Hz,
1 H), 7.08–6.98 (group of m, 4 H), 6.90 (t, 3J = 7.0 Hz, 1 H) {Harom},
5.54 (s, 1 H, =CH), 3.41 (AB, 2J = 22.8 Hz, 2 H, CH2), 3.25 (m, 4
H, NCH2CH2), 1.95 (m, 4 H, NCH2CH2), 1.92 (s, 3 H, CH3).
13C{1H} NMR (CDCl3): d = 145.0, 143.0, 142.6, 141.9, 140.3,
130.3, 129.7 (C=), 133.6, 129.0, 127.7, 126.9, 126.3, 122.5, 100.1
(=CH), 43.0, 37.0 (CH2), 18.4, 18.1, 12.7 (CH3).
Anal.Calcd for C23H27N (317.47): C, 87.02; H, 8.57. Found: C,
87.10; H, 8.67.
(E)-N,N-Diethyl-2-phenyl-1-(2,4,7-trimethyl-1H-inden-3-
yl)ethenamine (21)
In the same manner as described for 3, adduct 21 (0.37 g) was ob-
tained in 85% yield by the reaction of 6 (310 mg, 1.2 mmol) with
diethylamine (110 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
Anal. Calcd for C22H23N (301.43): C, 87.66; H, 7.69. Found: C,
87.58; H, 7.77.
1H NMR (CDCl3): d = 7.08–6.87 (group of m, 7 H) {Harom}, 5.58 (s,
1 H, =CH), 3.24 (AB, 2J = 23.0 Hz, 2 H, CH2), 3.35–3.19 (group of
m, 4 H, CH2CH3), 2.49 (s, 3 H), 2.41 (s, 3 H), 1.91 (s, 3 H) {CH3},
1.17 (br t, 6 H, CH2CH3).
13C{1H} NMR (CDCl3): d = 143.8, 143.7, 142.3, 141.2, 140.5,
135.5, 129.6, 128.6 (C=), 129.1, 127.7, 126.4, 125.2, 122.4, 99.8
(=CH), 43.0, 41.4 (CH2), 18.3, 18.0, 14.6, 13.0 (CH3).
1-[(E)-1-(4,7-Dimethyl-1H-inden-3-yl)-2-phenylethenyl]pyrro-
lidine (26)
In the same manner as described for 3, adduct 26 (0.35 g) was ob-
tained in 92% yield by the reaction of 5 (293 mg, 1.2 mmol) with
pyrrolidine (107 mg, 1.5 mmol) in Et2O (10 mL); yellow-brown oil.
1H NMR (CDCl3): d = 7.11–7.01 (m, 6 H), 6.91 (t, 3J = 7.2 Hz, 1 H)
{Harom}, 6.43 (t, 3J = 2.0 Hz, 1 H), 5.39 (s, 1 H) {=CH}, 3.35 (AB,
2J = 24.0 Hz, 2 H, CH2), 3.27 (m, 4 H, NCH2CH2), 2.48 (s, 3 H),
2.47 (s, 3 H) {CH3}, 1.96 (m, 4 H, NCH2CH2).
Anal. Calcd for C24H29N (331.49): C, 86.96; H, 8.82. Found: C,
87.04; H, 8.88.
13C{1H} NMR (CDCl3): d = 144.1, 143.1, 142.5, 142.0, 140.2,
130.4, 129.3 (C=), 132.2, 129.0, 127.8, 126.4, 126.26, 122.2, 98.6
(=CH), 47.8, 37.0, 25.3 (CH2), 18.3, 17.4 (CH3).
(E)-N-Butyl-1-(2-methyl-1H-inden-3-yl)-2-phenylethenamine
(22)
In the same manner as described for 3, adduct 22 (0.32 g) was ob-
tained in 81% yield by the reaction of 4 (300 mg, 1.3 mmol) with n-
butylamine (110 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
Anal. Calcd for C23H25N (315.45): C, 87.57; H, 7.99. Found: C,
87.50; H, 8.05.
1H NMR (CDCl3): d = 7.45–7.36 (m, 2 H), 7.27–7.15 (group of m,
5 H), 7.05–6.97 (m, 2 H) {Harom}, 5.61 (s, 1 H, =CH), 3.85 (AB,
2J = 26.0 Hz, 2 H, CH2), 3.23 (q, 3J = 7.0 Hz, 2 H, NCH2), 1.63 (m,
2 H), 1.35 (m, 2 H) {CH2CH2CH3}, 1.52 (s, 3 H, CH3), 0.87 (t,
3J = 7.2 Hz, 3 H, CH2CH3).
1-[(E)-2-Phenyl-1-(2,4,7-trimethyl-1H-inden-3-yl)ethenyl]pyr-
rolidine (27)
In the same manner as described for 3, adduct 27 (0.38 g) was ob-
tained in 98% yield by the reaction of 6 (310 mg, 1.2 mmol) with
pyrrolidine (107 mg, 1.5 mmol) in Et2O (10 mL); colorless crystals,
mp 82 °C.
1H NMR (CDCl3): d = 7.05–6.92 (m, 6 H), 6.84 (m, 1 H) {Harom},
5.35 (s, 1 H, =CHPh), 3.24 (AB, 2J = 24.0 Hz, 2 H, CH2), 3.24–3.15
(m, 4 H, NCH2), 2.38 (s, 6 H), 1.92 (s, 3 H) {CH3}, 1.91 (m, 4 H,
NCH2CH2).
13C{1H} NMR (CDCl3): d = 143.0, 142.9, 141.3, 141.1, 140.3,
136.2, 129.7, 128.2 (C=), 128.9, 127.8, 125.8, 125.1, 122.1, 98.9
(=CH), 47.5, 41.3, 25.3 (CH2), 18.3, 17.3, 14.3 {CH3}.
Anal. Calcd for C22H25N (303.44): C, 87.08; H, 8.30. Found: C,
82.25; H, 11.68; N, 5.99.
(E)-N-Butyl-1-(4,7-dimethyl-1H-inden-3-yl)-2-phenylethen-
amine (23)
In the same manner as described for 3, adduct 23 (0.29 g) was ob-
tained in 76% yield by the reaction of 5 (293 mg, 1.2 mmol) with n-
butylamine (110 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
1H NMR (CDCl3): d = 7.35–7.03 (group of m, 8 H) {Harom, =CH},
5.67 (s, 1 H, =CHPh), 4.09 and 3.77 (AB, 2J = 13.8 Hz, 2 H, CH2),
3.26 (q, 3J = 7.4 Hz, 2 H, NCH2), 2.38 (s, 3 H), 2.36 (s, 3 H) {CH3},
1.50 (m, 2 H), 1.35 (m, 2 H) {CH2CH2CH3}, 0.93 (t, 3J = 6.8 Hz, 3
H, CH2CH3).
Anal. Calcd for C24H27N (329.48): C, 87.49; H, 8.26. Found: C,
87.44; H, 8.33.
1-[(E)-1-(2-Methyl-1H-inden-3-yl)-2-phenylethenyl]piperidine
(28)
In the same manner as described for 3, adduct 28 (0.39 g) was ob-
tained in 95% yield by the reaction of 4 (300 mg, 1.3 mmol) with
piperidine (128 mg, 1.5 mmol) in Et2O (10 mL); yellow-brown oil.
Anal. Calcd for C23H27N (317.47): C, 87.02; H, 8.57. Found: C,
87.00; H, 8.66.
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

1044
P. V. Ivchenko et al.
PAPER
1H NMR (CDCl3): d = 7.57 (d, 3J = 7.5 Hz, 1 H), 7.45 (d, 3J = 7.2
Hz, 1 H), 7.31 (dd, 3J = 7.5, 8.4 Hz, 1 H), 7.20 (dd, 3J = 7.2, 8.4 Hz,
1 H), 7.10–6.97 (group of m, 5 H) {Harom}, 5.77 (s, 1 H, =CH), 3.31
(AB, J = 23.0 Hz, 2 H, CH2), 3.06 (m, 4 H, NCH2), 1.75 (s, 3 H,
CH3), 1.63 (m, 6 H, NCH2CH2CH2).
Anal. Calcd for C23H25NO (331.45): C, 83.34; H, 7.60. Found: C,
83.26; H, 11.74.
2
4-[(E)-2-Phenyl-1-(2,4,7-trimethyl-1H-inden-3-yl)ethenyl]mor-
pholine (33)
In the same manner as described for 3, adduct 33 (0.40 g) was ob-
tained in 96% yield by the reaction of 6 (336 mg, 1.3 mmol) with
morpholine (131 mg, 1.5 mmol) in Et2O (10 mL); yellow crystals;
mp 134 °C.
1H NMR (CDCl3): d = 7.14–7.07 (m, 5 H), 7.02 (m, 2 H) {Harom},
5.84 (s, 1 H, =CH), 3.78 (m, 4 H, OCH2), 3.28 (AB, 2J = 23.1 Hz, 2
H, CH2), 3.19–3.03 (m, 4 H, NCH2), 2.61 (s, 3 H), 2.42 (s, 3 H), 1.88
(s, 3 H) {CH3}.
Anal. Calcd for C23H25N (315.45): C, 87.57; H, 7.99. Found: C,
87.64; H, 7.91.
1-[(E)-1-(4,7-Dimethyl-1H-inden-3-yl)-2-phenylethenyl]piperi-
dine (29)
In the same manner as described for 3, adduct 29 (0.37 g) was ob-
tained in 94% yield by the reaction of 5 (293 mg, 1.2 mmol) with
piperidine (128 mg, 1.5 mmol) in Et2O (10 mL); yellow-brown oil.
1H NMR (CDCl3): d = 7.11–7.03 (m, 6 H), 6.96 (t, 3J = 7.2 Hz, 1 H)
{Harom}, 6.37 (t, 3J = 2.0 Hz, 1 H) 5.72 (s, 1 H) {=CH}, 3.30 (AB,
2J = 23.6 Hz, 2 H, CH2), 3.11 (m, 4 H, NCH2CH2), 2.59 (s, 3 H),
2.45 (s, 3 H) {CH3}, 1.63 (m, 6 H, NCH2CH2CH3).
13C{1H} NMR (CDCl3): d = 147.7, 143.3, 142.5, 142.2, 139.7,
130.1, 129.9 (C=), 134.3, 129.1, 127.7, 127.4, 126.1, 123.4, 104.4
(=CH), 48.6, 36.9, 25.9, 24.5 (CH2), 18.5, 18.31 (CH3).
13C{1H} NMR (CDCl3): d = 145.7, 143.5, 143.3, 141.3, 138.9,
134.4, 129.6, 128.6 (C=), 129.2, 127.8, 127.1, 125.3, 124.0, 106.3
(=CH), 66.9, 47.7, 41.4 (CH2), 18.4, 18.3, 14.6 (CH3).
Anal. Calcd for C24H27NO (345.48): C, 83.44; H, 7.88. Found: C,
83.40; H, 7.95.
3-[(E)-1-Ethoxy-2-phenylethenyl]-2-methyl-1H-indene (34)
In the same manner as described for 8, adduct 34 (0.34 g) was ob-
tained in 95% yield by the reaction of 4 (300 mg, 1.3 mmol) with
EtONa (102 mg, 1.5 mmol) in EtOH (10 mL); dark brown oil.
Anal. Calcd for C24H27N (329.48): C, 87.49; H, 8.26. Found: C,
87.42; H, 8.32.
1-[(E)-2-Phenyl-1-(2,4,7-trimethyl-1H-inden-3-yl)ethenyl]pipe-
ridine (30)
In the same manner as described for 3, adduct 30 (0.38 g) was ob-
tained in 92% yield by the reaction of 6 (310 mg, 1.2 mmol) with
piperidine (128 mg, 1.5 mmol) in Et2O (10 mL); yellow-brown oil.
1H NMR (CDCl3): d = 7.44 (d, 3J = 7.4 Hz, 1 H), 7.37 (d, 3J = 7.6
Hz, 1 H), 7.30 (dd, 3J = 7.6, 8.6 Hz, 1 H), 7.20 (dd, 3J = 7.4, 8.6 Hz,
1 H), 7.18–7.04 (group of m, 5 H) {Harom}, 6.13 (s, 1 H, =CH), 4.07
3
(q, J = 7.1 Hz, 2 H, OCH2), 3.36 (AB, 2 H, CH2), 1.81 (s, 3 H,
CH3), 1.45 (t, 3J = 7.1 Hz, 3 H, CH2CH3).
1H NMR (CDCl3): d = 7.09–7.03 (m, 2 H), 7.01–6.94 (m, 4 H), 6.87
(d, 3J = 7.4 Hz, 1 H) {Harom}, 5.59 (s, 1 H, =CH), 3.34–3.17 (m, 4
H, NCH2), 3.05 (AB, 2J = 23.8 Hz, 2 H, CH2), 2.35 (s, 3 H), 2.27 (s,
3 H), 2.02 (s, 3 H) {CH3}, 1.69 (m, 6 H).
Anal. Calcd for C20H20O (276.37): C, 86.92; H, 7.29. Found: C,
86.85; H, 7.36.
3-[(E)-1-Ethoxy-2-phenylethenyl]-4,7-dimethyl-1H-indene (35)
In the same manner as described for 8, adduct 35 (0.41 g) was ob-
tained in 89% yield by the reaction of 5 (318 mg, 1.3 mmol) with
EtONa (102 mg, 1.5 mmol) in EtOH (10 mL); dark brown oil.
Anal. Calcd for C25H29N (343.50): C, 87.41; H, 8.51. Found: C,
87.49; H, 8.44.
4-[(E)-1-(2-Methyl-1H-inden-3-yl)-2-phenylethenyl]morpho-
line (31)
In the same manner as described for 3, adduct 31 (0.35 g) was ob-
tained in 85% yield by the reaction of 4 (300 mg, 1.3 mmol) with
morpholine (131 mg, 1.5 mmol) in Et2O (10 mL); brown oil.
1H NMR (CDCl3): d = 7.85 (d, 3J = 7.6 Hz, 1 H), 7.45–7.03 (group
of m, 6 H) {Harom}, 6.51 (br s, 1 H), 6.01 (s, 1 H) {=CH}, 3.90 (q,
3J = 7.0 Hz, 2 H, OCH2), 3.36 (AB, br, 2 H, CH2), 2.57 (s, 3 H), 2.44
(s, 3 H) {CH3}, 1.49 (t, 3J = 7.0 Hz, 3 H, CH2CH3).
Anal. Calcd for C21H22O (290.40): C, 86.85; H, 7.64. Found: C,
86.80; H, 7.71.
3
1H NMR (CDCl3): d = 7.11–7.01 (m, 6 H), 6.91 (d, J = 7.2 Hz, 1
H) {Harom}, 6.43 (t, 3J = 2.0 Hz, 1 H) 5.39 (s, 1 H) {=CH}, 3.35 (AB,
2J = 24.0 Hz, 2 H, CH2), 3.27 (m, 4 H, NCH2CH2), 2.48 (s, 3 H),
2.47 (s, 3 H) {CH3}, 1.96 (m, 4 H, NCH2CH2).
3-[(E)-1-Ethoxy-2-phenylethenyl]-2,4,7-trimethyl-1H-indene
(36)
In the same manner as described for 8, adduct 36 (0.30 g) was ob-
tained in 71% yield by the reaction of 6 (362 mg, 1.4 mmol) with
EtONa (109 mg, 1.6 mmol) in EtOH (10 mL); red-brown oil.
13C{1H} NMR (CDCl3): d = 144.1, 143.1, 142.5, 142.0, 140.2,
130.4, 129.3 (C=), 132.2, 129.0, 127.8, 126.4, 126.26, 122.2, 98.6
(=CH), 47.8, 37.0, 25.3 (CH2), 18.3, 17.4 (CH3).
1H NMR (CDCl3): d = 7.26–7.10 (group of m, 5 H), 7.06 (d, 3J = 7.5
Anal. Calcd for C22H23NO (317.42): C, 83.24; H, 7.30. Found: C,
83.30; H, 11.73.
3
Hz, 1 H), 6.97 (d, J = 7.5 Hz, 1 H) {Harom}, 6.05 (s, 1 H, =CH),
4.15–3.95 (group of m, 2 H, OCH2), 3.25 (AB, 2J = 23.0 Hz, 2 H,
CH2), 2.51 (s, 3 H), 2.38 (s, 3 H), 1.87 (s, 3 H) {CH3}, 1.45 (t,
3J = 7.0 Hz, 3 H, CH2CH3).
4-[(E)-1-(4,7-Dimethyl-1H-inden-3-yl)-2-phenylethenyl]mor-
pholine (32)
In the same manner as described for 3, adduct 32 (0.39 g) was ob-
tained in 98% yield by the reaction of 5 (293 mg, 1.2 mmol) with
morpholine (131 mg, 1.5 mmol) in Et2O (10 mL); yellow crystals;
mp 112 °C.
Anal. Calcd for C22H24O (304.43): C, 86.80; H, 7.95. Found: C,
86.79; H, 8.04.
3-[(E)-1-(tert-Butylsulfanyl)-2-phenylethenyl]-2-methyl-1H-in-
dene (37)
In the same manner as described for 9, adduct 37 (0.36 g) was ob-
tained in 86% yield by the reaction of 4 (322 mg, 1.4 mmol) with t-
BuSNa (168 mg, 1.5 mmol) in Et2O (10 mL) and THF (2 mL); red-
brown oil.
1H NMR (CDCl3): d = 7.09–6.94 (m, 7 H) {Harom}, 6.33 (t, 3J = 2.0
Hz, 1 H) 5.71 (s, 1 H) {=CH}, 3.73 (m, 4 H, CH2O), 3.27 (AB,
3
2J = 23.4 Hz, J = 2.0 Hz, 2 H, CH2), 3.13–2.98 (m, 4 H, NCH2),
2.55 (s, 3 H), 2.39 (s, 3 H) {CH3}.
13C{1H} NMR (CDCl3): d = 148.1, 143.3, 142.2, 141.4, 138.9,
130.4, 129.8 (C=), 134.9, 127.9, 127.6, 126.4, 124.1, 105.5 (=CH),
67.0, 48.2, 37.0 (CH2), 18.5, 18.4 (CH3).
1H NMR (CDCl3): d = 7.62–7.13 (group of m, 10 H) {Harom, =CH},
3.33 (AB, 2 H, CH2), 1.88 (s, 3 H, CH3), 1.36 [s, 9 H, C(CH3)3].
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

PAPER
3-(Phenylethynyl)-1H-indenes Nucleophilic Addition
1045
Anal. Calcd for C22H24S (320.49): C, 82.45; H, 7.55. Found: C,
82.55; H, 7.47.
Diethyl (E)-2-Phenyl-1-(2,4,7-trimethyl-1H-inden-3-yl)eth-
enylphosphonate (42)
In the same manner as described for 10, adduct 42 (0.40 g) was ob-
tained in 84% yield by the reaction of 6 (362 mg, 1.4 mmol) with
diethyl phosphite (221 mg, 1.6 mmol) and NaH (36 mg, 1.5 mmol)
in Et2O (20 mL); yellow oil.
1H NMR (CDCl3): d = 7.70 (d, 3J = 25.0 Hz, 1 H), 7.45–6.80 (group
of m, 7 H) {Harom, =CH}, 4.24–4.06 (m, 4 H, OCH2CH3), 3.34 (AB,
2J = 23.0 Hz, 2 H, CH2), 2.45 (s, 3 H), 2.39 (s, 3 H), 2.05 (d, 4J = 4.3
Hz, 3 H) {Cind-CH3}, 1.34 (t, 3J = 6.6 Hz, 3 H), 1.28 (t, 3J = 6.6 Hz,
3 H) {CH2CH3}.
3-[(E)-1-(tert-Butylsulfanyl)-2-phenylethenyl]-4,7-dimethyl-
1H-indene (38)
In the same manner as described for 9, adduct 38 (0.36 g) was ob-
tained in 77% yield by the reaction of 5 (342 mg, 1.4 mmol) with t-
BuSNa (168 mg, 1.5 mmol) in Et2O (10 mL) and THF (2 mL);
brown oil.
1H NMR (CDCl3): d = 7.27–7.14 (group of m, 6 H), 7.04 (m, 2 H),
6.35 (t, 3J = 2.2 Hz, 1 H) {Harom, =CH}, 3.31 (AB, 2J = 24.2 Hz, 2
H, CH2), 2.58 (s, 3 H), 2.41 (s, 3 H) {CH3}, 1.41 [s, 9 H, C(CH3)3].
Anal. Calcd for C24H29O3P (396.46): C, 72.71; H, 7.37. Found: C,
72.79; H, 7.44.
Anal. Calcd for C23H26S (334.52): C, 82.58; H, 7.83. Found: C,
82.66; H, 7.77.
(1-Cyclopenten-1-ylethynyl)benzene (44)
3-[(E)-1-(tert-Butylsulfanyl)-2-phenylethenyl]-2,4,7-trimethyl-
1H-indene (39)
In the same manner as described for 9, adduct 39 (0.30 g) was ob-
tained in 71% yield by the reaction of 6 (362 mg, 1.4 mmol) with t-
BuSNa (168 mg, 1.5 mmol) in Et2O (10 mL) and THF (2 mL)
brown oil.
1H NMR (CDCl3): d = 7.27–7.14 (group of m, 5 H), 7.07 (s, 1 H),
7.04 (d, 3J = 7.7 Hz, 1 H), 6.96 (d, 3J = 7.7 Hz, 1 H) {Harom, =CH},
3.23 (AB, 2J = 22.9 Hz, 2 H, CH2), 2.63 (s, 3 H), 2.37 (s, 3 H), 1.94
(s, 3 H) {CH3}, 1.44 [s, 9 H, C(CH3)3].
13C{1H} NMR (CDCl3): d = 142.9, 141.3, 140.4, 137.9, 137.2,
133.3, 129.5, 128.7 (C=), 134.1, 129.4, 128.2, 127.9, 126.7, 125.4
(=CH), 46.8, 41.6 (CH2 and C), 31.2, 19.0, 18.3, 15.3 (CH3).
In the same manner as described for 1, compound 44 (22.2 g) was
obtained in 66% yield by the reaction of cyclopentanone (16.8 g,
0.20 mol) with PhC≡CMgBr (0.30 mol) in Et2O (200 mL) with sub-
sequent dehydration (PTSA/Et2O, 6 h); pale-yellow liquid; bp 56–
58 °C/0.1 Torr.
1H NMR (CDCl3): d = 7.50 (m, 3 H), 7.33 (m, 2 H) {C6H5}, 6.20
(m, 1 H, =CH), 2.60 (m, 2 H), 2.52 (m, 2 H), 1.99 (m, 2 H) {CH2}.
13C{1H} NMR (CDCl3): d = 137.7, 131.3, 128.1, 127.9 (=CH),
124.4, 123.5 (C=), 90.3, 86.7 (C≡C), 36.3, 33.3, 23.3 (CH2).
Anal. Calcd for C13H12 (168.23): C, 92.81; H, 7.19. Found: C,
92.84; H, 7.16.
4-(Phenylethynyl)-1,2-dihydronaphthalene (45)
Anal. Calcd for C24H28S (348.55): C, 82.70; H, 8.10. Found: C,
82.77; H, 8.07.
In the same manner as described for 1, compound 45 (0.37 g) was
obtained in 78% yield by the reaction of 1-tetralone (29.2 g, 0.20
mmol) with PhC≡CMgBr (0.30 mmol) in Et2O (200 mL) with sub-
sequent dehydration (PTSA/Et2O, 2 h); pale-yellow liquid; bp 126–
130 °C/0.1 Torr.
Diethyl (E)-1-(2-Methyl-1H-inden-3-yl)-2-phenylethenylphos-
phonate (40)
In the same manner as described for 10, adduct 40 (0.39 g) was ob-
tained in 81% yield by the reaction of 4 (300 mg, 1.3 mmol) with
diethyl phosphite (221 mg, 1.6 mmol) and NaH (34 mg, 1.4 mmol)
in Et2O (20 mL); red-brown oil.
1H NMR (CDCl3): d = 7.84–7.16 (group of m, 10 H) {Harom, =CH},
4.16 (qd, 3J = 17.3 Hz, 4 H, OCH2CH3), 3.15 (AB, 2J = 18.0 Hz, 2
H, CH2), 2.03 (d, 3J = 4.0 Hz, 3 H, CH3), 1.33 (t, 3J = 6.9 Hz, 3 H,
CH2CH3), 1.27 (t, 3J = 6.9 Hz, 3 H, CH2CH3).
1H NMR (CDCl3): d = 7.90–7.20 (group of m 9 H) {Harom}, 6.66 (t,
3
3J = 4.9 Hz, 1 H, =CH), 2.93 (t, J = 8.0 Hz, 4 H, CH2), 2.93 (tt,
3J = 8.0, 4.9 Hz, 4 H, CH2CH=).
13C{1H} NMR (CDCl3): d = 134.8, 132.4, 123.2, 121.5 (C=), 135.2,
131.3, 128.1, 128.0, 127.4, 127.1, 126.3, 124.8 (=CH), 90.0, 87.1
(C≡C), 26.9, 23.4 (CH2).
Anal. Calcd for C18H14 (230.30): C, 93.87; H, 6.13;. Found: C,
82.25; H, 11.68.
Anal. Calcd for C22H25O3P (368.41): C, 71.72; H, 6.84. Found: C,
82.25; H, 11.68.
1,1-Dimethyl-3-(phenylethynyl)-1H-indene (46)
In the same manner as described for 1, compound 46 (10.3 g) was
obtained in 42% yield by the reaction of 3,3-dimethylindan-1-one
(16.0 g, 0.1 mol) with PhC≡CMgBr (0.15 mol) in Et2O (100 mL)
with subsequent dehydration (PTSA/Et2O, 2 h). The product was
purified by column chromatography (hexane); pale-yellow crystals;
mp 74 °C.
Diethyl (E)-1-(4,7-Dimethyl-1H-inden-3-yl)-2-phenyleth-
enylphosphonate (41)
In the same manner as described for 10, adduct 41 (0.44 g) was ob-
tained in 96% yield by the reaction of 5 (318 mg, 1.3 mmol) with
diethyl phosphite (221 mg, 1.6 mmol) and NaH (34 mg, 1.4 mmol)
in Et2O (20 mL); yellow oil.
3
1H NMR (CDCl3): d = 7.61 (m, 2 H), 7.58 (d, J = 7.4 Hz, 1 H),
1H NMR (CDCl3): d = 7.65 (d, 3J = 25.8 Hz, 1 H), 7.35 (d, 3J = 7.6
7.41–7.30 (group of m, 6 H) {Harom}, 6.72 (s, 1 H, =CH), 1.41 (s, 6
H, CH3).
3
Hz, 2 H), 7.24–7.18 (m, 3 H), 6.97 (d, J = 7.6 Hz, 1 H), 6.92 (d,
3J = 7.6 Hz, 1 H), 6.43 (m, 1 H) {Harom, =CH}, 4.24–4.06 (m, 4 H,
13C{1H} NMR (CDCl3): d = 152.3, 141.5, 123.2, 122.4 (C=), 150.9,
131.7, 128.4, 126.8, 126.0, 121.1, 120.6 (=CH), 92.8, 83.3 (C≡),
49.4 (C), 24.4 (CH3).
OCH2CH3), 3.40 (m, 2 H, CH2), 2.41 (s, 3 H), 2.34 (s, 3 H) {Cind
-
CH3}, 1.35 (t, 3J = 7.1 Hz, 3 H), 1.23 (t, 3J = 7.1 Hz, 3 H)
{CH2CH3}.
13C{1H} NMR (CDCl3): d = 142.9, 141.1 (d), 139.7 (d), 135.0 (d),
130.2, 129.5, 128.6 (C=), 143.3 (d), 132.4 (d), 130.0, 129.2, 129.1,
128.4, 126.2 (=CH), 62.2 (d), 62.1 (d) {OCH2}, 37.3 (CH2), 18.5,
18.3, 16.2 (d), 16.1 (d) (CH3).
Anal. Calcd for C19H16 (244.33): C, 93.40; H, 6.60. Found: C,
93.45; H, 6.55.
Acknowledgment
31P NMR (CDCl3): d = 7.71.
Financial support by Basell Polyolefins is gratefully acknowledged.
Anal. Calcd for C23H27O3P (382.43): C, 72.23; H, 7.12. Found: C,
72.33; H, 11.72.
Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York

1046
P. V. Ivchenko et al.
PAPER
(5) (a) Foster, P.; Rausch, M. D.; Chien, J. C. W. J. Organomet.
Chem. 1997, 527, 71. (b) Stradiotto, M.; McGlinchey, M. J.
Coord. Chem. Rev. 2001, 219-221, 311.
(6) 3-Ethynyl-(1H)-indene synthesis: Padwa, A.; Austin, D. J.;
Gareau, Y.; Kassir, J. M.; Xu, S. L. J. Am. Chem. Soc. 1993,
115, 2637.
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Synthesis 2007, No. 7, 1038–1046 © Thieme Stuttgart · New York