Diene-yne cyclisation reactions of 1-ethynyl-2-vinyl-3,4- dihydronaphthalenes and 1-ethynyl-2-vinylnaphthalenes

Article abstract of DOI:10.3184/030823408X375214

The reaction of 1-ethynyl-2-vinyl-3,4-dihydronaphthalenes and 1-ethynyl-2-vinylnaphthalenes over RuCI₂(p-cymene) PPh₃ leads to 9,10-dihydrophenanthrenes and phenanthrenes in those cases where the ethynyl group in the substrates carries a terminal proton. When 1-phenylethynyl-2-vinyl-3,4-dihydronaphthalenes or 1-phenylethynyl-2- vinylnaphthalenes are reacted over Pt(PPh₃)₄, 1-methylene-1H-benz[e]-4,5-dihydroindenes and 1-methylene-1H-benz[e]indenes are formed.

Full text of DOI:10.3184/030823408X375214

JOURNAL OF CHEMICAL RESEARCH 2008
DECEMBER, 669-678
RESEARCH PAPER 669
Diene-yne cyclisation reactions of 1-ethynyl-2-vinyl-
3,4-dihydronaphthalenes and 1-ethynyl-2-vinylnaphthalenes
Masataka Watanabea, Kodai Shiinea, Keiko Idetab, Taisuke Matsumotob and Thies Thiemanna*
alnterdisciplinary Graduate School of Engineering and blnstitute of Materials Chemistry and Engineering, Kyushu University, 6-1,
Kasuga-koh-en, Kasuga-shi, Fukuoka 816-8580, Japan
The reaction of 1-ethynyl-2-vinyl-3,4-dihydronaphthalenes
PPh3 leads to 9,10-dihydrophenanthrenes and phenanthrenes in those cases where the ethynyl group in the
substrates carries a terminal proton. When 1-phenylethynyl-2-vinyl-3,4-dihydronaphthalenes
2-vinylnaphthalenes are reacted over Pt(PPh3)4, 1-methylene-1H-benz[e]-4,5-dihydroindenes
and 1-ethynyl-2-vinylnaphthalenes
over RuCI2(p-cymene)
or 1-phenylethynyl-
and 1-methylene-1 H-
benz[e]indenes are formed.
Keywords: diene-ynes, cyclisation, ruthenium, platinum, catalysis, fulvenes
While ene-diyne cyclisations (Bergman reaction) have been
subject to extensive investigations,l-4 diene-yne cyclisations
have been studied much less frequently (Scheme I).
In contrast to ene-diynes, the geometry of diene-ynes is far
from optimal for intramolecular cyclisation reactions. Thus,
cyclisations of this type can only be accomplished when the
geometry of the transition state is greatly changed from that
of the educts. Nevertheless, it is possible to submit diene-
ynes thermally to intramolecular cyclisation reactions. Thus,
the parent compound, hexa-I,3-dien-5-yne (2, R = H) can be
transformed to benzene at 274°C (Hopf cyclisation, Scheme 1)5
and at 500°C, the reaction gives benzene in 50% yield.5
Further diene-ynes have been subjected to similar conditions
to furnish cyclisation productS.6-11In certain cases, one or
both olefinic moieties of the diene component can be part of
an aromatic system. In these cases the Hopf cyclisation has
been used for the construction of bowl-shaped polycyclic
aromatic hydrocarbons (pAHS)6,7,8as sub-units of fullerenes.
Efforts have been devoted to the elucidation of the mechanism
of the thermal cyclisation of diene-ynesI2-16 and it has
been found that different mechanisms compete, depending
on the reaction temperature. At lower temperatures, up to
550°C, the cyclisations are thought to occur through a two-
step mechanism via cyclohexa-I,2,4-trienes B with a strong
biradical character. At higher temperatures, it has been found
that an isomerisation of the alkynes to vinylidenecarbenes D
occurs, which then react by a 1,6-CH insertion (Scheme I).
Competing 1,5-CH insertion can yield indenes and
acenaphthenes as side-products,17 depending on the substrates.
A fulvene structure has also been isolated as side product,15
most likely arising via a biradical intermediate. As the thermal
diene-yne cyclisations, mentioned above, all necessitate high
temperatures, most functional groups are not compatible with
the reaction conditions. Thus, milder reaction conditions
are preferable with lower reaction temperatures as found in
the cyclisation reactions of yne-ene allenes 4 to benzenes 5
(Myers-Saito-cyclisation, Scheme 2)18,19and to fulvenes 6
(Schmittel cyclisation, Scheme 2).20 In the case of terminal
acetylenes such as 7, the cyclisation of diene-ynes can proceed
via transformation of a metal vinylidene species, e.g. via
G (vide infra) (Scheme 3). Here, the use of ruthenium21,22
(Scheme 3) and tungsten,23-25and with less favourable results,
Bergman cyclisation
•
•
•
o
•
A
Thermal cyclisation of diene-ynes (Hopf-cyclisation)
•
w
'
.
,
,
.
,
1#
1#
CJ
R
U
R
eY
R
C
R
C
3
B
2
R
R
1,2-R
1,6-CH
c:
1#
6
C
R
D
3
2
Scheme
1
* Correspondent. E-mail:thies@cm.kyushu-u.ac.jp

670 JOURNAL OF CHEMICAL RESEARCH 2008
Thermal cyclisationof yne-ene-allenes (Myers-Saito-cyclisation)
•
H-Donor
C
R§,
•
•
..
cc
CC
I """ CR'R'
I """ CHR'R'
I
"""oAR'
•
5
E
4
Thermal cyclisationof yne-ene-allenes (Schmittel-cyclisation)
R
R
H-Donor
•
•
F
6
4
R = Phenyl
Scheme
2
of chromium and molybdenum catalysts has been reported.
Tetralones such as 13 can easily be transformed into the
In the case of diene-ynes with internal acetylene moieties, the
complexation of a metal to the alkyne moiety in 1l2-fashion26,27
as in 10 can be envisaged (Scheme 3). This would give a unit
possessing more of the character and geometry of an alkene
allowing subsequent cyclisation of the complexed diene-yne.
We have recently developed a one-pot synthesis of l-ethynyl-
2-vinyl-3,4-dihydronaphthalenes 15 from l-bromo-2-formyl-
3,4-dihydronaphthalenes 14,28 and we became interested in
their metal catalysed yne-diene cyc1isation reactions, utilising
both of the latter approaches.
corresponding bromo-enaldehydes, such as 14, by the Arnold-
Vilsmeier reaction (Scheme 4).29 The bromo-enaldehydes
14 can then react in a one-pot Sonogashira-coupling-Wittig
reaction to furnish l-ethynyl-2-vinyl-3,4-dihydronaphthalenes
15a, c, d28and, after desilyation with tetra-n-butylammonium
fluoride (TBAF) in wet THF, to give 15b and 15e. I-Ethynyl-
2-vinylnaphthalene (1St) was synthesised from 15a, either
by desilylation to 15b (TBAF, wet THF) and subsequent
dehydration with 2,3-dicyano-4,5-dichloroparabenzoquinone
(DDQ) in refluxing benzene, or by dehydration of 15a to 15g
Ru-catalyseddiene-ynecyclisation(ref.21)
s
s
PPh3
eI/cymene
# R u
Ru(p-cymene)CI2PPh3
••
.-7"
\
CI
7
G
8
l]2-complexatioonfacetyleneswithpt
Ph3,\
/PPh3
pt
(ref.26)
Pt(PPh3)4
....~
Ph
Ph
,.
40 ..'
••
9
10
X1
X1
X1
X2
X2
X2
?
II
M(O)Lx
•..
•..
H
12
Scheme
3

JOURNAL OF CHEMICAL RESEARCH 2008 671
Access to diene-ynes via Arnold-Vilsmeier and subsequent one-pot Sonogashira-Wittig olefination protocol
(Refs. 28, 29)
o
Br
CHO ===_-R1
••
Pd(PPh3l2CI2
Cui
Ph3P=CHC02Et
[29a]
15
14
13
15a: R1 = TMS; R2 = OEt [28]
15b: R1 = H, R2 = OEt [28]
15c: R1 = Ph, R2 = OEt [28]
15d: R' = TMS, R2 = CH3 [28]
15e: R1 = H, R2 = CH3 [28]
..::::J TBAF, wet TH F
..::::J TBAF, wetTHF
Scheme
4
with DDQ in refluxing toluene and subsequent desilylation
using TBAF in wet THF (Scheme 5). Compound lSi was
prepared from lSe by Luche reduction (NaBH4, CeC13)
followed by acetylation (Ac20, Py) (Scheme 6). It is necessary
to protect the hydroxy group in ISh for the subsequent diene-
yne cyc1isation.
were needed (74°C vs 40°C) than in the ruthenium catalysed
transformation of ISh to 16a, when 1,1,I-trichloroethane was
used as solvent (Scheme 6). While initially a 1l2-complexation
of the platinum species to the alkyne moiety was taken into
consideration when planning the reaction sequence (vide
supra), it may well be that a metal vinylidene intermediate is
also active in this catalytic reaction. Such end-on complexations
have been discussed in the absorption of acetylene itself on
Pt-surfaces, where the upright bridge bonded fl-vinylidene of
the form Pt2 =C=CH2 has been characterised by vibrational
spectroscopy.33 Laser ablated Pt atoms have also been
found to react with acetylene to form platinum vinylidene
(pt =C=CH2).34It has been known that noble metals on solid
supports can go into solution and redeposit on the support,
so that even for solid supported catalysts of this type a
homogeneous reaction can be considered.35
Compound 16a can be derivatised36 to two potent
inhibitors of human steroid 5a-reductase.37,38 Thus, 16a can
be hydrolysed to inhibitor 16a-H with KOBut!H20 in ether
according to a general procedure by Gassman (Scheme 6).39
It can also be dehydrogenated to 16c, the direct precursor
of potent steroid Sa-reductase inhibitor phenanthrene-2-
carboxylate. Alternatively, 16c can be prepared by diene-yne
cyc1isation from lSf.
The resultant l-ethynyl-2-vinyldihydronaphthalenes
lSb,
lSe, and lSi and l-ethynyl-2-vinylnaphthalene lSf were
subjected to metal-catalysed diene-yne cyc1isation reactions.
While Iwasawa and Maeyama23,24have shown that diene-
ynes, possessing a terminal proton, can be cyc1ised in
presence ofW(CO)5(THF), in the present case, Ru(p-cymene)
C12PPh33owas used as the catalyst, as described by Medic
and Pauly.21In this manner, diene-ynes lSb, lSe, lSf, and lSi
were cyc1ised in fair yield to give a ready access to areno-
annelated compounds 16a-d (Scheme 6). The reaction is
thought to proceed via a ruthenium vinylidene intermediate
(see Scheme 3).21
Recently, Fuerstner and Mamane31 described the Pt-
catalysed cyc1isation of 2-ethynylbiphenyls to phenanthrenes,
which incorporates aspects of the diene-yne cyclisation. Initial
experiments on the cyc1isation of dihydronaphthalene based
diene-ynes of type 15 with Pt(pPh3)4 as catalyst, however,
gave the corresponding phenanthrenes as the cyc1isedproduct in
very poor yield (typically: Pt(pPh3)4, mesitylene, 135°C, 45 h,
2% yield). It must be noted, however, that the cyc1isation of
lSb to 16a also proceeds in the presence of platinum dichloride.
Here, platinum dicWoride was immobilised on a solid support
(carbon nanofibres, CNFS).32 Higher reaction temperatures
Next, we turned our attention to diene-ynes with an
internal alkyne unit, in which l-arylethynyl-2-vinyl-3,4-
dihydronaphthalenes 15 were used as substrates. Again, the
compounds can be prepared by a one-pot or by a stepwise
Sonogashira-Wittig olefination (Schemes 4 and 7).
H
TMS
R
0
0
0
II
OEt
II
OEt
OEt
DDQ
toluene
DDQ
benzene
1 (
15g
15f
••
36h
1.5h
(85%)
(65%)
15b
---,
1155gf 'RR =TMS
=H (89%)----...J TBAF, wet THF
15a
Scheme
5

672 JOURNAL OF CHEMICAL RESEARCH 2008
~
C02Et Ru(p-cymene)CI2PPh3 c&l,::(i~~j
NH4PF6
~
I ~
(68%)
(41%)
••
CH2CI2, refl., 90h
~
1~
1~(R=E0
(PtCI2 on CNF, CH3CCI3, refl., 40h 30%)
08C1OCH3
Ru(p-cymene )CI2PPh3
NH4PF6
~ I ~
DDQ
benzene
for 16c: 61%
~
(48%)
15e
16b
08C102Et
Ru(p-cymene )CI2PPh3
NH4PF6
~ I ~
~
n
16c
(40%)
15f
15e
I
NaBH4, CeC13
MeOH(89%)
OAc
•
OR
Ru(p-cymene )CI2PPh3
NH4PF6
II
••
15h: R = H ---, AC20, Py
15i: R = O A c..-J (89%)
Scheme
6
A number of platinum complexes and platinum salts were
used in the initial attempts at diene-yne cylisation of these
substrates. When tetrakis(triphenylphosphine )platinum(O)
[Pt(pPh3)4] was added to 15c in CD2CI2, a platinum complex
was formed, which could be characterised by IH and 13CNMR
spectroscopy, but which could not be identified unequivocally.
This platinum complex did not react further and give cyclised
products under the conditions tried (DMF, rt; DMF, 80°C;
DMF, reflux; dry thermolysis on quartz [350°C; P < 10 Torr]).
However, the reaction of 15c in mesitylene at 135°C in the
C02Et
~R
(R~CN,CH3)
Pd(PPh3)2CI2
Cui
R
14
17 a [ref. 45]
C02Et
derivative
derivative
(R = CN) (85%)
derivative
(R = CH3) (78%)
,-
15j: dihydronaphthalene
(R = CN) (61%)
for 15j: DDQ, benzene
~
15k: naphthalene
151: dihydronaphthalene
Br
Pd(PPh3)2CI2
(73%)
Cui
18
17b (89%)
~
benzene
(48%)
15c
Scheme
7

JOURNAL OF CHEMICAL RESEARCH 2008 673
R
R
R
Pt(PPh3)4
+
..
mesitylene
R
E-18a: R = H (8%)
E-18b: R =CN (7%)
E-18c: R =CH3 (10%)
R minor
R = H (15c), CN (15j), CH3 (151)
Z-18a: R = H (31%) major
Z-18b: R =CN (28%)
Z-18c: R = CH3 (24%)
R
C02Et
+
Pt(PPh3)4
..
mesitylene
major
Z-18d: R = H (23%)
Z-18e: R =CN (20%)
E-18d: R = H (8%)
E-18e: R =CN (7%)
R = H (15m), CN (15k)
Scheme
8
presence of Pt(pPh3)4 led to a reddening of the solution and
E- and Z-isomer. Neat Z-isomers, e.g. 18b, have been found
to undergo slow decomposition. It must be noted that under
the strict exclusion of oxygen (air), the reaction does not
take place. In the presence of oxygen, a small amount of the
solvent mesitylene is oxidised to 3,5-dimethylbenzaldehyde
which, in certain cases, complicates the work-up as residual
3,5-dimethylbenzaldehyde has to be removed in vacuo after
column chromatographic separation of the compounds.
This indicates that under the reaction conditions the Pt(O)
species is partially oxidised, most probably to Pt(ll). Instead
l-methylene-IH-benz[e]-4,5-dihydroindenes
in moderate yield (Scheme 8).
18a was isolated
The fulvenes form as a mixture of E- and Z-isomers, where
the Z-isomer is the predominant isomer. In the Z-isomers, the
protons of the benzo- as well as the phenyl group are shifted
to high-field due to the proximity of the two aromatic ring
systems. The stereostructure of the E-isomer was confirmed
by NOE experiments. Over prolonged periods of time, the
pure Z-isomer equilibrates in solution to give a mixture of
Br
Br
C02Et
CHO
Ph3P=CHC02Et
CHCI3
HO
20
(76%)
19
C02Et
Pt(PPh3)4
no reaction
•
mesitylene
Pd(PPh3)2CI2
Cui
21 (60%)
Scheme
9

674 JOURNAL OF CHEMICAL RESEARCH 2008
CN
CN
=-O-CN
•
mesitylene
22
23 (50%)
CN
eN
EtO,
NC
+
+
25 (5%) minor
26a (23%) major
26b (8%) minor
Scheme 10
700 and Nippon Denshi llR-AQ20M machines. 1H and 13C NMR
spectra were recorded with a JEOL EX-270 spectrometer. The
chemical shifts are relative to TMS (solvent CDC13,unless otherwise
noted). Partially, assignments of BC signals were aided by DEPT ( =
Distortionless Enhancement by Polarisation Transfer) measurements.
Mass spectra were measured with a JMS-Ol-SG-2 spectrometer (EI,
70 eV). Column chromatography was carried out on Wakoge1300.
Diisopropylamine (DIPA) was stored over KOH and distilled from
KOH and DME was distilled from calcium hydride before use. Tet
rakis(triphenylphosphine)platinum(O) [Pt(PPh3)4] and bis(triphenyl-
phosphine)palladium(II) dichloride [(PPh3hPdC12] were obtained
commercially. Ru(p-cymene)C12PPh3 was prepared according to
the literature.32 4-Cyanophenylacetylene was synthesised from
4-bromobenzonitrile and trimethylsilylacetylene with subsequent
of mesitylene, 4-tert-butylbenzene can be used as a solvent.
The reaction does not proceed with PtCl2 as catalyst under
otherwise identical conditions. As part of our on-going
study41-43on E-ring annelated estranes as novel ligands for
the estrogen receptor, a solution of the estrane based diene-
yne 20 in mesitylene was heated in the presence ofPt(pPh3)4,
but in this case unfortunately no reaction could be observed
(Scheme 9).
2-Arylethyny1cinnamate 24 was also heated in mesitylene
in the presence of Pt(pPh3)4 at 135°C. The substrate 24 was
prepared from 2-bromobenzaldehyde (22) by a sequential
Sonogashira coupling-Wittig
olefination (Scheme 10).
desilylation
(i.
4-bromobenzonitrile,
trimethylsilylacetylene,
Reversal of the transformation sequence, i.e. Wittig
olefination followed by Sonogashira coupling, gave the
product in much lower yield as the Sonogashira coupling
proceeds only with difficulty (10% yield). Again, a solution of
N,N-diisopropylamine, Pd(PPh3hC12, CuI, DME; ii. tetrabutyl-
ammonium fluoride, THF). Compounds 1429., 15a-e28 and
17a45 were prepared according to the literature. The conjugated
phosphoranes
ethoxycarbonylmethylidenetriphenylphosphorane,
2-arylethyny1cinnamate
24 in mesitylene
undergoes
benzoylmethylidenetriphenylphosphorane,
and acetylmethylidene-
triphenylphosphorane were synthesised following the literature
methods (i) ethyl bromoacetate, bromoacetophenone orbromoacetone,
triphenylphosphine, chloroform; (ii) aq. Na2C03, CH2C12).46-48
In general, the diene-yne cyclisation reactions of terminal
alkyenes with Ru(p-cymene)C12PPh3 were carried out under an inert
atmosphere (argon), while diene-yne cyclisations ofintemal aIkynes
were run under a normal atmosphere (air). Deaerated solvents were
used for the Sonogashira coupling reactions.
cyclisation, when reacted over Pt(pPh3)4 and gives fulvene 26
as E- and Z-isomers. Single crystals of Z-26 could be obtained
and an X-ray crystal structure of Z-26 has been carried out
confirming the structure of26.44 Interestingly, in this reaction,
fulvene 25 is formed as a side-product. The structure of 25
was also verified by X-ray crystal structure analysis.44
In conclusion, l-ethynyl-2-vinyl-3,4-dihydronaphthalenes
15b, 15e and lSi as well as l-ethynyl-2-vinylnaphthalenes 15f
have been found to undergo diene-yne cyclisation reactions
to dihydrophenanthrenes and phenanthrenes, respectively,
catalysed by Ru(p-cymene )CI2PPh3. In an exploratory
reaction, it was found that the reaction proceeds also with
PtCl2 immobilised on a carbon nanofibre material [CN28-
580°C, HCI treated]. Diene-ynes 15 and 24, which possess
an internal alkyne moiety, could be cyclised to fulvenes 18,
25 and 26, catalysed by Pt(pPh3)4' Studies on the scope of the
latter reaction concerning the range of possible substrates and
catalysts as well as mechanistic studies are underway.
Ethyll-ethynylnapthalen-2-ylacrylate
(15t). Method A: A solution
of15b (350 mg, 1.4 mmol) and DDQ (567 mg, 2.5 mmol) in benzene
(20 ml) was heated at 80°C for 90 min. The mixture was then
concentrated in vacuo. The residue was subjected to column
chromatography on silica gel (hexane/ether 6:1) to give 15f (225 mg,
65%) as a colourless solid; m.p. 108°C. (Found: 250.0989. C17H1402
requires: M+, 250.0994); Vrnax (KBr/cm-~ 3240, 2980, 1700, 1631,
1306, 1257, 1181, 1034, 989, 816, 755; ~ (270 MHz, CDC13) 1.36
(3H,t, 3J = 7.0 Hz), 3.88 (lH, s), 4.30 (2H, q, 3J = 7.0 Hz), 6.59 (lH, d,
3J= 15.9 Hz), 7.52-7.83 (5H, m), 8.42 (lH, d, 3J= 8.4 Hz), 8.47 (lH,
d, 3J= 15.9 Hz); <>c(67.8 MHz, CDC13) 14.4,60.6,79.0,89.2,120.6,
121.3, 122.3, 127.1, 127.6, 128.1, 129.2, 133.5, 133.8, 135.1, 142.5,
166.9; MS (EI, 70 eV) m/z (%) 250 (M+) (9.9), 176 (16), 58 (100).
(Found: C, 81.75; H, 5.70. C1#1402 requires, C, 81.58; H, 5.64%).
Method B: A mixture of15a (973 mg, 3.0 mmol) and DDQ (1.36 g,
6.0 mmol) in toluene (30 ml) was held at reflux for 36 h. Thereafter,
the cooled solution was concentrated in vacuo, and the residue was
subjected to column chromatography on silica gel (hexane/ether 10:1)
Experimental
General
Melting points were measured on a Yanaco microscopic hot-stage
and are uncorrected. IR spectra were measured with JASCO IR-
to give ethyl I-trimethylsilylethynylnapthalen-2-ylacrylate
(15g)

JOURNAL OF CHEMICAL RESEARCH 2008 675
Ethyl phenanthrene-2-carboxylate (16c): Method A: 15f (75 mg,
(830 mg, 85%) as a colourless oil; (Found: 323.1468. C2oH2302Si
requires: MW, 323.1467 [FAB]); Vrnax(neat/cm-I) 3058,2150, 1713,
1632, 1294, 1260, 1175, 1041, 846; ~ (270 MHz, CDC13) 0.40
(9H, s, SiMe3), 1.39 (3H, t, 3J= 7.3 Hz), 4.32 (2H, q, 3J= 7.3 Hz),
6.61 (lH, d, 3J = 16.2 Hz), 7.55-7.84 (3H, m), 8.40 (lH, m), 8.50
(lH, d, 3J= 16.2 Hz); Oe (67.8 MHz, CDC13)0.0,14.3,60.5,100.3,
107.7, 120.2, 122.3, 122.4, 127.2, 127.4 (2C), 127.5, 128.1, 128.8,
133.5, 134.7, 142.8, 166.9; MS (FAB, 3-nitrobenzyl alcohol) m/z (%)
323 (MW) (100), 277 (32), 205 (29). A solution of 15g (447 mg,
1.39 mmol) and TBAF (2.0 mmol) in THF (7 ml) was stirred for
2 h at RT. Water (30 ml) was then added and the mixture was extracted
with chloroform (3 x 15 ml). The combined organic phase was dried
over anhydrous MgS04, concentrated in vacuo, and the residue was
subjected to column chromatography on silica gel (hexane/ether 5 : 1)
to give 15f (310 mg, 89%).
0.3 mmol) was added to
a
solution of Ru(p-cymene)C12PPh3
(8.5 mg, 15 J.lffiol)and ~F6
(4.9 mg, 30 J.lffiol)in CH2Cl2(4 mi).
The solution was stirred for 50 h at reflux. The crude mixture was
subjected to column chromatography on silica gel (hexane/ether 4: 1)
to give 16c (30 mg, 40%) as a colourless solid; (Found: M+, 250.0990.
C16172H7I,1460021r,1e5q2u9ir,e1s4:9M4,1+3,8265,01.306979,41)3;0v8r,n1a1x9(1K, Br)/emm-o12,918009,22,912042,7,1871124,,
746; ~ (270 MHz, CDC13)1.47 (3H, t, 3J = 7.0 Hz), 4.49 (2H, q, OClh,
3J= 7.0 Hz), 7.62-7.73 (2H, m), 7.79 (lH, d, 3J= 9.2 Hz), 7.83 (lH, d,
3J = 9.2 Hz), 7.93 (lH, m), 8.27 (lH, dd, 3J = 8.4 Hz, 4J= 1.9 Hz), 8.62
(lH, d, 4J= 1.9 Hz), 8.7~.75 (2H, m); Be (67.8 MHz, CDC13,DEPT
90, DEPT 135) 14.42 ( +, CH3), 61.13 (-), 122.86 ( + , CH), 123.28
(+,CH), 126.47 (+,CH), 126.94 (+,CH), 127.24 (+,CH), 127.64 (+,
CH), 127.74 ( + , CH), 128.34 (Cqual),128.70 ( + , CH), 129.76 (Cqual),
130.78 ( +, CH), 131.43 (Cqual),132.92 (Cquad,133.30 (Cqual),166.70
(Cqual>C=O); MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 251 (6.7)
[MH+], 250 (6.9) [M+]. Method B: A mixture of 16a (104 mg, 0.41
mmol) and DDQ (227 mg, 1.0 mmol) in benzene (10 mi) was kept at
reflux for 10 h. The reaction mixture was concentrated in vacuo and the
residue was subjected to column chromatography on silica gel (hexane/
ether 2:1) to give 16c (71 mg,61%).
4-(1-Ethynyl-3,4-dihydronaphthalen-2-yl)-but-3-en-2-o1
(15h):
To a mixture of 15e (112 mg, 0.5 mmol) and CeC13 (292 mg,
1.2 mmol) in MeOH (7 mi) was added NaB~ (38 mg, 1.0 mmol) at
O°C. The resulting mixture was stirred at rt for 5 min. The solution
was diluted carefully with water. The mixture was then extracted
with CHC13(3 x 10 mi). The organic phase was dried over anhydrous
MgS04 and concentrated in vacuo. Column chromatography of
the residue on silica gel (hexane/ether/CHC13 1: 1:1) gave 15h
(94 mg, 89%) as a colourless oil; (Found: 224.1202. CIJII60 requires:
9,lO-Dihydrophenanthrene-2-carboxylic
acid (16a-H): To a
mixture of16a (70 mg, 0.28 mmol), tert-KOBu(400 mg, 3.6 mmol) in
ether (10 ml) was added water (0.1 mi) and the resulting mixture was
stirred for 12 h at RT. Water (15 mi) was then added and the solution
was acidified with conc. aq. HCl. Then, the mixture was extracted
with chloroform (3 x 15 ml), the organic phase dried over anhydrous
MgS04 and concentrated in vacuo. Column chromatography of the
residue on silica gel (ether) gave 16a-H (43 mg, 68%) as a colourless
solid, m.p. 213 °C (lit. 214-215°C); (Found: M+, 224.0834. CI5H1202
requires: M+, 224.0837); vrnax(KBr)/cm-1 2924, 1685, 1611, 1427,
1295, 1255, 1190,934, 748; ~ (270 MHz, CDC13) 2.87-2.94 (4H,
m), 7.28-7.38 (3H, m), 7.61-7.67 (2H, m), 7.99 (lH, d, 4J= 2.4 Hz),
8.06 (lH, dd, 3J= 8.3 Hz, 4J= 2.4 Hz); Be (67.8 MHz, CDC13)28.77,
28.82, 123.75, 124.46, 127.18, 127.68, 128.35, 128.68, 128.97,
129.91, 133.44, 137.48, 138.09, 139.86, 171.44; MS (70 eV) m/z
(%): 224 (78) [W], 179 (100).
M+, 224.1201); vrnax(neat)/cm-I 3286,3016,2968,2884,2090,
1487,
1452, 1367, 1294, 1244, 1216, 1144, 1123, 1060, 968, 944, 762; ~
(270 MHz, CDC13)1.37 (3H, d, 3J= 6.7 Hz, CH3), 1.56 (lH, bs, OH),
2.54 (2H, dd, 3J = 8.6 Hz, 3J = 7.6 Hz), 2.83 (2H, dd, 3J = 8.6 Hz,
3J= 7.6 Hz), 3.52 (lH, s), 4.53 (lH, dt, 3J= 6.7 Hz, 3J= 6.7 Hz), 6.07
(lH, dd, 3J= 15.9Hz, 3J= 6.7 Hz), 7.13-7.25 (4H,m), 7.67 (lH, d, 3J=
7.3 Hz); Be (67.8 MHz, CDC13)23.41, 23.73, 27.15,69.16,79.84,85.37,
118.65, 125.80, 126.65, 127.02, 127.59, 129.18, 133.21, 135.00, 136.26,
142.61; MS (EI, 70 eV) m/z (%) 224 (M+,31),179 (53),165 (100).
4-(1- Ethynyl-3, 4-dihydronaphthalen- 2-yl)-2-acetylbut-3 -en-2-o1
(15i): To 15h (85 mg, 0.38 mmol) in dry CH2Cl2 (3 mi) was added
pyridine (68 mg, 0.90 mmol) and acetic anhydride (77 mg, 0.76 mmol).
The solution was stirred for 5 h at rt. Water (10 ml) was then added,
and the mixture was extracted with chloroform (2 x 10 mi) The
organic phase was dried over anhydrous MgS04 and concentrated in
vacuo. Column chromatography on silica gel (hexane/ether/CHC13
2.5: 1 : 1) gave 15i (90 mg, 89%) as a slowly crystallising, colourless
oil; (Found: 266.1304. CIsHIS02 requires: M+, 266.1307); vrnax(neat/
cm-I) 3284 (sharp peak), 3024, 2980, 2934, 2090 (weak), 1733, 1452,
2-(1-Acetoxyethyl)-9,1O-dihydro-phenanthrene (16d): 15i (90 mg,
0.3[4] mmol) was added to a solution of Ru(p-cymene)C12PPh3
(8.5 mg, 15 /lmol) and ~PF6
(4.9 mg, 30 J.lffiol) in CH2C12
(5 ml). The solution was stirred for 36 h at reflux. The crude mixture
was subjected to column chromatography on silica gel (hexane/
ether 4: 1) to give 16c (65 mg, 72%); oil; (Found: 266.1305. Calcd
for CIsHIS02: 266.1307); Vrnax(neat/em-I) 2930, 1735, 1369, 1240,
1063, 1024, 945, 830, 770, 735; OH (270 MHz, CDC13) 1.57 (3H,
d, 3J = 6.7 Hz), 2.11 (3H, s, CH3), 2.88 (4H, bs), 5.89 (lH, q,
3J = 6.7 Hz); 7.22-7.33 (5H, m), 7.72 (2H, m); Oe (67.8 MHz,
CDC13) 21.41, 22.06, 28.94, 29.09, 72.19, 123.68, 123.82, 124.71,
125.95, 126.93, 127.44, 128.10, 134.12, 134.22, 137.32, 137.94,
140.62, 170.39; MS (EI, 70 eV) m/z (%) 266 (M+, 100), 224 (22),
207 (75), 178 (39).
1371, 1240, 1156, 1041,970,766;
BH (270 MHz, CDC13) 1.41 (3H,
d, 3J= 6.5 Hz, C(OAc)Cfu), 3.53 (lH, s), 2.08 (3H, s, OCOClh);
2.53 (2H, dd, 3J= 8.1 Hz, 3J= 7.6 Hz), 2.83 (2H, dd, 3J= 8.1 Hz,
3J = 7.6 Hz), 5.56 (lH, dt, 3J = 6.8 Hz, 3J = 6.5 Hz), 5.99 (lH,
dd, 3J = 15.9 Hz, 3J = 6.8 Hz), 7.11-7.24 (4H, m), 7.68 (lH, d,
3J = 7.6 Hz); Be (67.8 MHz, CDC13) 20.41, 21.38, 23.59, 27.09,
71.12, 79.68, 85.52, 119.21, 125.90, 126.67, 127.00, 127.69, 130.85,
131.33,133.17,135.04,142.20,170.32;
MS (EI, 70 eV) m/z (%) 266
(M+, 41), 224, 206 (89), 191 (100), 178 (59), 165 (71).
Ethyl 9,lO-dihydrophenanthrene-2-carboxylate (16a): A mixture
of 15b (252 mg, 1.0 mmol), Ru(p-cymene)C12PPh3 (28.4 mg,
1-(4-Cyanophenylethynyl)-2-ethoxycarbonylethenyl-3,
4-dihydro-
naphthalene (15i): solution of 17a (280 mg, 0.92 mmol),
A
5 mol%) and ~PF6
(10 mol%, 16.3 mg) in CH2C12(13 mi) was
4-cyanophenylacetylene (234 mg, 1.84 mmol), Pd(PPh3hC12 (20 mg,
2.8 x 10-5mol), CuI (10 mg, 5.2 x 10-5mol) and dry diisopropylamine
(DIPA, 0.8 mi) in anhydrous DME (8 mi) was kept at 80°C for 19 h.
The reaction mixture was cooled, water (20 ml) was added, and the
mixture was extracted with chloroform (3 x 15 ml). The combined
organic phase was dried over anhydrous MgS04 and concentrated
in vacuo. Column chromatography of the residue on silica gel
(hexane/ether/CHC13 2: 1: 1) gave 15j (199 mg, 61%) as a colourless
solid; m.p. 116°C; (Found: M+, 353.1415. C2~1902N requires
stirred at 45°C for 90 h under inert atmosphere. The crude reaction
mixture was then concentrated and the residue was subjected to
column chromatography on silica gel (hexane/ether 8: 1) to yield 16a
(104 mg, 41%) as an oil. Vrnax(neat/cm-I) 2960, 1720, 1600; B
H
(270 MHz, CDC13) 1.41 (3H, t, 3J= 7.1 Hz), 2.88-2.95 (4H, m), 4.39
(2H, q, 3J= 7.1 Hz), 7.25-7.35 (3H, m), 7.79 (2H, d, 3J= 7.9 Hz),
7.91 (lH, s), 7.97 (lH, dd, 3J= 7.9 Hz, 4J= 1.9 Hz); Be (99.45 MHz,
CDC13) 14.37, 28.81 (2C), 60.86, 123.57, 124.31, 128.23 (2C),
128.37, 129.02, 129.22 (2C), 133.57, 137.28, 137.94, 138.83, 166.61
(CO); MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 253 (MW) (7.5).
2-Acetyl-9,lO-dihydrophenanthrene (16b): 15e (33 mg, 0.15 mmol)
was added to a solution of Ru(p-cymene)C12PPh3 (8.6 mg, 15 /lmol)
M, 353.1416); Vrnax(KBr/em-l) 3060, 3020, 2950, 2198, 756; B
H
(270 MHz, CDC13) 1.35 (3H, t, 3J= 7.0 Hz), 2.63 (2H, m), 2.91 (2H,
m),4.28 (2H, q, 3J= 7.0 Hz), 6.18 (lH, d, 3J= 15.7 Hz), 7.20 (lH, m),
7.26-7.30 (2H,m), 7.66 (2H, d, 3J= 8.6 Hz), 7.71 (2H, d, 3J= 8.6 Hz),
7.74 (lH, m), 8.28 (lH, d, 3J = 15.7 Hz); Be (67.8 MHz, CDC13)
14.3 (CH3), 22.6 (CH2), 26.9 (CH2), 60.6 (OCH2), 89.3 (Cqual),97.9
and ammonium hexafluorophosphate ~PF6]
(5.0 mg, 30 /lmol)
in CH2C12(3 ml). The solution was stirred for 27 h under reflux.
The crude material was then subjected to column chromatography on
silica gel (hexane/ether/CHC13 4: 1: 1) to give 16b (16 mg, 48%) as
a colourless solid; (Found: MH+, 223.1122. CI6HI50 requires: MH+,
223.1123); vrnax(KBr)/em-1 2932, 1679, 1604, 1555, 1483, 1417,
1357, 1273, 1253, 1181, 960, 833, 771, 734, 671; ~ (270 MHz,
CDC13)2.61 (3H, s, COCH3), 2.86-2.98 (4H, m), 7.21-7.31 (3H, m),
7.78-7.91 (4H, m); Be (67.8 MHz, CDC13) 26.6, 28.8, 28,9, 123.8,
124.4, 127.2, 128.1, 128.4, 128.6, 133.5, 135.8, 137.5, 138.0, 139.2,
197.8; MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 223 (47) [MW],
222 (28) [M+].
(Cg'!al),111.9 (C~ual)'118.4 (Cqual), 119.8 (CH), 125.2 (C'lual), 126.6
(CH), 126.9 (CH), 127.5 (CH), 127.7 (Cqual),129.1 (CH), 132.1 (2C,
CH), 132.2 (2C, CH), 132.4 (Cqual),135.8 (Cqual),140.7 (C'lual),142.9
(CH), 167.1 (Cqual>CO); MS (EI, 70 eV) m/z = 353 (M+) ~100), 325
(69),280 (83), 277 (82).
1-(4-Cyanophenylethynyl)-2-ethoxycarbonylethenyl-naphthalene
(15k): A mixture of 15j (144 mg, 0.41 mmol) and DDQ (167 mg,
0.72 mmol) in benzene (6 mi) was kept at 80°C for 12 h. Direct
column chromatography of the cooled mixture on silica gel (hexane/
ether/CHC13 1: 1: 1) yielded 15k (122 mg, 85%) as pale yellow

676 JOURNAL OF CHEMICAL RESEARCH 2008
needles; m.p. 167°C; (Found: M+, 351.1263. C24H1702N requires
M, 351.1259); Vrnax (KEr/cm-l ) 3060, 2978, 2924, 2200, 814,
756; BH (270 MHz, CDC13) 1.38 (3H, t, 3J = 7.0 Hz), 4.32 (2H, q,
3J = 7.0 Hz), 6.63 (lH, d, 3J = 16.2 Hz), 7.56-7.87 (9H, m), 8.42
at 135°C for 12 h. The cooled reaction mixture was separated over
silica gel (eluant, initially hexane, then hexane/CHC13/ether 10: 1: 1)
to give Z-18a as a deep-red oil (41 mg, 31%); (Found: M+, 328.1458.
C23H2002requires M, 328.1463); vrnax(neat/em-I) 2950, 1720, 749;
Be (67.8 MHz, CDC13) 14.4 (CH3), 23.7 (CH2), 29.5 (CH2), 59.8
(OCH2), 125.4 (CH), 125.7 (CH), 127.0 (CH), 127.1 (Cqual), 127.2
(CH), 127.5 (Cqual),128.1 (2C, CH), 129.2 (CH), 131.7 (Cqual),132.3
(2C, CH), 135.4 (Cqual), 135.9 (Cquad, 136.4 (Cqual), 146.1 (Cquad,
164.1 (Cqual>CO); MS (EI, 70 eV) m/z (%) = 328 (M+) (100), 255
(42),253 (33), 181 (12), 165 (13), 149 (18), 77 (27); and E-18a as
a red oil (10 mg, 8%); (Found: M+, 328.1462. C23H2002requires M,
328.1463); vrnax(neat/em-I) 2956, 1710, 758; ~ (270 MHz, CDC13)
0.78 (3H, t, 3J= 7.0 Hz, CH3), 2.56 (2H, m), 2.85 (2H, m), 3.67 (2H,
q, 3J = 7.0 Hz, OCH2), 7.17 (lH, m), 7.25-7.44 (8H, m), 7.55 (lH, d,
3J= 7.3 Hz), 8.00 (lH, s); Be (150.9 MHz, CDC13) 13.6 (CH3), 23.1
(CH2), 29.7 (CH2), 60.4 (OCH2), 125.0 (CH), 126.6 (CH), 126.9 (CH),
127.8 (Cqual),128.3 (CH,2C), 128.5 (CH), 129.1 (CH), 131.1 (CH,
2C), 131.9 (Cqual), 135.0 (Cqual), 137.6 (Cqual), 137.9 (Cqual), 139.3
(lH, d, 3J
= 8.4 Hz), 8.53 (lH, d, 3J = 16.2 Hz); Be (67.8 MHz,
CDC13) 14.4 (CH3), 60.7 (OCH2), 89.3 (Cqual),99.4 (C!lUal),112.0
(Cqual), 118.4 (C~ual)' 120.5 (CH), 121.3 (Cqual), 122.5 (CH), 126.8
(CH), 127.7 (CH), 127.8 (CH), 128.3 (CH), 129.6 (CH), 132.1 (2C,
CH), 132.2 (2C, CH), 133.3 (Cqual),133.6 (C,\ual),134.9 (Cqual),142.4
(CH), 166.8 (Cqual>CO); MS (EI, 70 eV) m/z (%) = 351 ~M+)(78),
277 (100), 249 (30), 130 (52) (Found: C, 82.21; H, 4.81, N, 4.06.
C24H1702Nrequires, C, 82.03; H, 4.88; N, 3.99%).
1- (4- M ethylphenylethynyl)-2
-ethoxycarbonyl
ethenyl-3, 4-
dihydronaphthalene (151): A solution of 17a (504 mg, 1.63 mmo1),
4-methy1pheny1acety1ene (359 mg, 3.10 mmo1), Pd(PPh3hC12 (20 mg,
2.8 x 10-5mol), CuI (4 mg, 2.1 x 10-5mol) and dry diisopropy1amine
(DIPA, 0.44 m1) in anhydrous DME (10 ml) was kept at 70°C for
77 h. The reaction mixture was cooled, water (40 m1)was added, and
the mixture was extracted with chloroform (3 x 30 m1).The combined
organic phase was dried over anhydrous MgS04 and concentrated
in vacuo. Column chromatography of the residue on silica gel
(hexane/ether/CHC13 8:1:1) gave 151 (437 mg, 78%) as a slowly
crystallising oil; (Found: MH+, 343.1697. C2~2302 requires MH,
351.169~ [FAB]); Vrnax(neat/em-I) 3063, 29356~2198, 1710, 1610,
981,756, OH (270 MHz, CDC13) 1.35 (3H, t, J -7.0 Hz, CH3), 2.39
(3H, s, CH3), 2.60 (2H, m), 2.86 (2H, m), 4.27 (2H, q, 3J = 7.0 Hz,
OCH2), 6.12 (lH, d, 3J= 15.7 Hz), 7.16-7.29 (3H, m), 7.18 (2H, d,
3J = 8.1 Hz), 7.52 (2H, d, 3J = 8.1 Hz), 7.83 (lH, m), 8.36 (lH, d,
3J = 15.7 Hz); Oe (67.8 MHz, CDC13) 14.3 (CH3), 21.6 (CH3), 23.5
(CH2), 27.1 (CH2), 60.4 (OCH2), 84.7 (Cqual>ethyny1), 100.5 (Cqual>
ethyny1), 118.8 (CH), 119.9 (Cqual),126.3 (Cqual),126.8 (CH), 126.9
(CH), 127.3 (CH), 128.7 (CH), 129.2 (2C, CH), 131.6 (2C, CH),
133.1 (Cqual),136.0 (Cqual),143.5 (CH), 138.7 (Cqual),139.0 (Cqual),
143.6 (CH), 167.3 (Cqual>CO); MS (FAB, 3-nitrobenzy1 alcohol) m/z
(%) 343 (MW) (1.2).
(Cgual),140.8 (CQuad,141.7 (CH), 143.3 (CH), 166.0 (C'1ualC>O); MS
(El, 70 eV) m/z (%) = 328 (M+) (100), 252 (46),181 (29),77 (52).
1-(E/Z)-4-Cyanophenylmethylene-2-ethoxycarbonyl-1
H-benz[ eJ-
4,5-dihydroindene (E/Z-18b): A mixture of 15j (180 mg, 0.5 mmo1)
and Pt(PPh3)4 (33 mg, 2.6 x 10-5mol) in mesity1ene (4 m1) was kept
at 135°C for 12 h. Direct column chromatography of the cooled
reaction mixture on silica gel (initially hexane/CHC13/ether 5: 1: 1
to elute mesity1ene, then hexane/CHC1/ether 3 : 1 : 1) afforded Z-18b
(50 mg, 28%) as a dark red solid; (Found: M+, 353.1420. C24HI902N
requires M, 353.1416); vrnax(KEr/em-l) 2958, 2200, 1723; BH (270
MHz, CDC13) 1.37 (3H, t, 3J= 7.3 Hz), 2.52 (2H, m), 2.86 (2H, m),
4.31 (q, 2H, 3J= 7.3 Hz), 6.33 (lH, d, 3J= 7.0 Hz), 6.61 (lH, m),
6.94 (lH, m), 7.13 (lH, d, 3J= 6.7 Hz), 7.31 (lH, s), 7.44 (4H, vs),
8.62 (lH, s); Be (67.8 MHz, CDC13) 14.4 (CH3), 23.6 (CH2), 29.3
(CH2), 60.0 (OCH2), 112.1 (Cqual),118.6 (Cqual),125.5 (CH), 126.3
(CH), 126.8 (CH), 127.2 (Cqual), 127.6 (CH), 129.2 (Cqual), 131.0
(Cqual),131.7 (2C, CH), 132.4 (2C, CH), 135.0 (Cqual),136.0 (Cqual),
139.6 (CH), 140.9 (Cquad, 141.6 (CH), 163.8 (Cqual>CO); MS (EI,
70 eV) m/z (%) = 353 (M+) (100),280 (38),278 (31); and E-18b
(12 mg, 7%) as a red oil; (Found: M+, 353.1416. C24HI902N requires
1-Phenylethynyl-2-ethoxycarbonylethenylnaphthalene
(15m):
Method A. A solution of 15c (231 mg, 0.70 mmo1) and dich10ro-
dicyanobenzoquinone (DDQ, 286 mg, 1.26 mmo1) in benzene (9 ml)
was kept at reflux for 12 h. The cooled solution was subjected directly
to column chromatography on silica gel (hexane/ether/CHC13 6: 1: 1)
to furnish 15m (109 mg, 48%) as a slowly crystallising, colourless
oil; (Found: M+, 326.1307. C23HI802 requires M, 326.1307); Vrnax
(KEr/cm-l ) 3056, 2978, 2924, 2202, 1712, 1598, 1303, 1259, 1176,
M, 353.1416); vrnax(neat/em-I) 2965, 2205, 1715; B
H
(270 MHz,
CDC13) 0.94 (3H, t, 3J 7.3 Hz), 2.58 (2H, m), 2.87 (2H, m),
=
7.11-7.72 (5H, m), 7.68 (4H, vs), 7.90 (lH, s); MS (EI, 70 eV) m/z
(%) = 353 (W ) (11),280 (15), 141 (34).
l-(E/Z)-p- Tolylmethylene-2 -ethoxycarbonyl-1 H-benz[ eJ-4,5-
dihydroindene (E/Z-18c): A mixture of 151 (290 mg, 0.85 mmo1)
and Pt(PPh3)4 (56 mg, 4.5.10-5 mol) in mesity1ene (6 ml) was kept
at 135°C for 48 h. Column chromatography of the residue on silica
gel (hexane/ether/CHC13 20: 1: 1) gave Z-18c (69 mg, 24%) as a red
oil; (Found: M+, 342.1628. C2~2202 requires: M+, 342.1620); vrnax
1038,814,753;
BH (270 MHz, CDC13) 1.38 (3H, t, 3J= 7.0 Hz), 4.32
(2H, q, 3J= 7.0 Hz), 6.63 (lH, d, 3J= 15.9 Hz), 7.41-7.85 (lOH, m),
8.51 (lH, d, 3J= 7.8 Hz), 8.61 (lH, d, 3J= 15.9 Hz); Be (67.8 MHz,
CDC13) 14.3 (CH3), 60.6 (CH2), 85.3 (Cquad, 101.6 (Cqual), 120.0
(CH), 122.5 (CH), 122.6 (Cqual), 123.0 (Cqual), 127.2 (CH), 127.5
(CH), 127.6 (CH), 128.2 (CH), 128.5 (2C, CH), 128.7 (CH), 128.8
(CH), 131.7 (2C, CH), 133.4 (Cquad,133.6 (Cqual),134.1 (C'jual),142.9
(CH), 167.1 (C ual>CO); MS (EI, 70 eV) m/z (%) = 326 ~51) (M+),
298 (51), 252 (f00), 105 (48). Method B: A mixture of23a (260 mg,
0.85 mmo1), pheny1acety1ene (156 mg, 1.53 mmo1), CuI (15 mg,
7.8 x 10-5mol), Pd(PPh3hC12 (30 mg, 4.3 x 10-5mol), and dry DIPA
(0.9 ml) in dry DME (9 m1)was kept at 70°C for 19 h. To the cooled
solution was given water (15 m1) and the mixture was extracted with
chloroform (2 x 20 m1). The combined organic phase was dried over
anhydrous MgS04, concentrated in vacuo and separated over column
chromatography on silica gel (hexane/ether/CHC13 5: 1: 1) to give
15m (202 mg, 73%).
(neat/em-I) 2954,1722,1250,1220,752;
BH (270 MHz, CDC13) 1.37
(3H, t, 3J= 7.0 Hz), 2.29 (3H, s, CH3), 2.52 (2H, m), 2.86 (2H, m),
4.30 (2H, q, 3J= 7.0 Hz), 6.54 - 6.65 (2H, m), 6.91 (lH, m), 6.97
(2H, d, 3J = 7.8 Hz), 7.11 (lH, d, 3J = 7.8 Hz), 7.27 (lH, s), 7.28
(2H, d, 3J= 7.8 Hz), 8.66 (lH, s); Be (67.8 MHz, CDC13) 14.4 (CH3),
21.4 (CH3), 23.8 (CH2), 29.6 (CH2), 59.8 (OCH2), 125.4 (CH), 125.6
(CH), 127.0 (CH), 127.2 (CH), 128.8 (2C, CH), 129.2 (Cqual),131.3
(Cqual), 132.0 (Cqual), 132.6 (2C, CH), 133.6 (Cqual), 135.9 (Cqual),
137.8 (Cqual), 139.7 (C9.1'ad,139.8 (CH), 143.6 (CH), 145.9 (Cjlual),
164.2 (Cqual>CO); MS (H, 70 eV) m/z (%) = 342 (66) (M+), 297 ~15),
269 (25), 253 (24), 149 (40), 58 (100) and E-18c (29 mg, 10%) as a
slowly solidifying red oil; (Found: M+, 342.1628. C24H2202requires:
M+, 342.1620); vrnax(neat/em-I) 2960, 1715, 1245, 750; ~ (270
MHz, CDC13)0.83 (3H, t, 3J= 7.3 Hz, CH3), 2.39 (3H, s, CH3), 2.57
(2H, m), 2.83 (2H, m), 3.74 (2H, q, 3J= 7.3 Hz, OCH2), 7.17-7.30
(5H, m), 7.20 (2H, d, 3J= 8.1 Hz), 7.33 (2H, d, 3J= 8.1 Hz), 7.55
(lH, d, 3J= 7.3 Hz), 7.99 (lH, s); Be (67.8 MHz, CDC13) 13.7 (CH3),
21.6 (CH3), 22.9 (CH2), 29.6 (CH2), 60.2 (OCH2), 125.0 (CH), 126.4
(CH), 126.8 (CH), 127.6 (Cqual),128.3 (CH), 128.5 (Cqual),128.9 (2C,
CH), 131.3 (2C, CH), 131.9 (Cqual),134.9 (Cqual),135.0 (Cqual),137.6
(Cqual), 139.4 (C~ual)' 140.3 (Cqual), 141.9 (CH), 142.8 (CH), 167.5
(C ual>CO); MS ~EI, 70 eV) m/z (%) = 342 (100) (M+), 269 (50).
l-(E/Z)- Phenylmethylene- 2-ethoxycarbonyl-1 H-benz[ eJindene
(E/Z-18d): A solution of 15k (109 mg, 0.46 mmo1) and Pt(PPh3)4
(30 mg, 2510-5 mol) in mesity1ene (3 m1)was kept at 135°C for 12 h.
Direct chromatography of the cooled reaction mixture on silica gel
(hexane/CHC13/ether 5: 1:1) gave Z-18d (25 mg, 23%) as a red-orange
solid; m.p. 121°C; (Found: M+, 326.1310. C23HI802 requires M,
326.1307); Vrnax(KEr/cm-l ) 2952, 1718, 1225, 752; ~ (270 MHz,
CDC13) 1.42 (3H, t, 3J = 7.3 Hz), 4.36 (2H, q, 3J = 7.3 Hz), 6.87
(lH, m), 7.18-7.33 (5H, m), 7.42-7.44 (2H, m), 7.53 (lH, d,
Ethyl (E)-3-(1-bromonaphthalen-2-yl)-acrylate (17b): A mixture
of 1-bromo-2-formylnaphtha1ene (18, 765 mg, 3.24 mmo1) and
ethoxycarbonylmethy1idenetripheny1phophorane (2.81 g, 8.09 mmo1)
in chloroform (3 ml) was placed into a beaker closed with Saran
Wrap® and was heated in an oven at 100°C for 2 h. Direct column
chromatography of the cooled reaction mixture on silica gel (hexane/
CHC13/ether 5:1:1) gave 17b (876 mg, 89%) as a colourless solid;
m.p. 124°C; (Found: M+, 304.0095. CI5H130279Brrequires M,
304.0099); vrnax(KEr/cm-l) 3057, 1700, 1596, 810, 770, 751; B
H
(270 MHz, CDC13) 1.37 (3H, t, 3J = 7.0 Hz, CH3), 4.31 (2H, q,
3J= 7.0 Hz, OCH2), 6.48 (lH, d, 3J= 15.9 Hz), 7.54-7.82 (5H, m),
8.37 (lH, m), 8.38 (lH, d, 3J= 15.9 Hz); Be (67.8 MHz, CDC13) 14.3
(CH3), 60.6 (OCH2), 121.6 (CH), 123.9 (CH), 126.8 (Cqual), 127.7
(CH), 127.9 (CH), 128.0 (CH), 128.1 (CH), 128.2 (CH), 132.1 (Cqual),
132.6 (Cqual),134.9 (Cquad, 143.9 (CH), 166.5 (Cqual>CO); MS (EI,
70 eV) m/z (%) 306 ([8IBr]M+), 304 ([79Br]M+),225 (45), 197 (100).
1-(E/Z)-Phenylmethylene-2-ethoxycarbonyl-1
H-benz[ eJ-4,5-
dihydroindene (E/Z-18a): A solution of 15c (132 mg, 0.40 mmo1)
and Pt(PPh3)4 (35 mg, 2.8 x 10-5mol) in mesity1ene (3 ml) was kept

JOURNAL OF CHEMICAL RESEARCH 2008 677
3J= 8.1 Hz), 7.70-7.77 (3H, m), 8.71 (lH,s); Be (67.8 MHz, CDC13)
14.4 (CH3), 60.3 (OCH2), 121.4 (CH), 125.1 (CH), 125.4 (CH), 127.5
(CH), 128.4 (Cqual),128.6 (2C, CH), 128.7 (CH), 128.8 (CH), 130.1
(CH), 131.2 (2C, CH), 131.8 (Cqual), 133.2 (Cqual), 133.8 (Cqual),
137.5 (Cqual), 138.7 (Cquad, 138.8 (CH), 140.1 (CH), 140.4 (Cqual),
164.5 (Cqual>CO); MS (EI, 70 eV) m/z (%) = 326 (100) (M+), 281
(23),252 (73) andE-18d (9 mg, 8%) as a red-orange oil; (Found: M+,
326.1306. C23HI802 requires M, 326.1307); vrnax(neat/em-I) 2953,
1717, 1220, 749; ~ (270 MHz, CDC13)0.87 (3H, t, 3J = 7.3 Hz), 3.67
(2H, q, 3J= 7.3 Hz), 7.38-7.61 (9H, m), 7.76 (lH, d, 3J= 8.1 Hz),
7.87 (lH, d, 3J = 7.8 Hz), 8.54 (lH, s), 8.56 (lH, d, 3J = 8.9 Hz);
Be (67.8 MHz, CDC13) 13.6 (CH3), 60.6 (OCH2), 121.2 (CH), 123.5
(CH), 125.0 (CH), 127.5 (CH), 128.3 (2C, CH), 128.5 (CH), 129.3
(CH), 130.0 (CH), 130.7 (2C, CH), 132.3 (Cqual),132.6 (Cquad,133.9
(Cqual),134.3 (Cqual),138.4 (Cqual),138.5 (Cqual),139.3 (CH), 139.9
(Cqual),140.8 (CH), 166.4 (Cqual>CO); MS (EI, 70 eV) m/z (%) = 326
(M ') (52), 252 (33), 149 (42).
1-(E/Z)-4-Cyanophenylmethylene-2 -ethoxycarbonyl-1 H-benz[ eJ
indene (E/Z-18e): A mixture of 15k (144 mg, 0.40 mmo1) and
Pt(PPh3)4 (28 mg, 2.3 x 10-5 mol) in mesity1ene (3 m1) was kept
at 135°C for 48 h. Column chromatography of the cooled mixture
on silica gel (hexane/ether/CHC13) gave Z-18e (29 mg, 20%) as a
red-orange solid; m.p. 190°C; (Found: M+, 351.1257. C24H1702N
requires M, 351.1259); vrnax(KBr/em-l ) 2954, 2205, 1725, 1225,
748; BH (270 MHz, CDC13) 1.41 (3H, t, 3J = 7.0 Hz), 4.37 (2H, q,
3J= 7.0 Hz), 6.91 (lH, m), 7.10 (lH, d, 3J= 8.9 Hz), 7.25-7.28 (lH,
m), 7.48-7.55 (5H, m), 7.74-7.81 (3H, m), 8.63 (lH, s); Be (67.8
MHz, CDC13) 14.4 (CH3), 60.4 (OCH2), 111.8 (Cquad, 118.7 (Cqual),
121.5 (CH), 125.5 (CH), 125.9 (CH), 127.0 (CH), 128.1 (Cqual),129.1
(CH), 130.9 (CH), 131.6 (2C, CH), 131.7 (Cqual), 132.2 (2C, CH),
132.4 (Cqual), 134.0 (Cquad, 136.5 (CH), 140.2 (CH), 140.8 (Cqual),
141.1 (C?'lUal1),42.1 (Cqual),164.2 (Cqual>CO); MS (EI, 70 eV) m/z (%)
= 351 (M+) (100), 323 (16), 306 (24),277 (56); and E-18e as a red-
orange oil (10 mg, 7%); (Found: M+, 351.1255. C24H1702Nrequires
M, 351.1259); vrnax(neat/em-I) 2952, 2203,1715, 753; ~ (270 MHz,
CDC13)0.99 (3H, t, 3J= 7.0 Hz), 3.76 (2H, q, 3J= 7.0 Hz), 7.43-7.71
(8H, m), 7.80 (lH, d, 3J= 8.4 Hz), 7.89 (lH, d, 3J= 8.1 Hz), 8.41
(lH, s), 8.48 (lH, d, 3J= 8.9 Hz); Be (67.8 MHz, CDC13) 13.8 (CH3),
60.7 (OCH2), 111.6 (Cquad, 118.6 (Cquad, 121.3 (CH), 123.3 (CH),
125.4 (CH), 127.9 (CH), 129.1 (Cqual),129.2 (Cqual),130.1 (2C, CH),
131.0 (2C, CH), 131.8 (2C, CH), 131.9 (Cqual),132.3 (Cqual),134.5
4'-Cyano-2-formyldiphenylacetylene (23): A lnixture of 2-bromo-
benzaldehyde (22, 810 mg, 4.40 mmo1), 4-cyanopheny1acety1ene
(720 m1,5.67 mmo1), Pd(PPh3hC12 (40 mg, 5.6'10-5mol), CuI (15 mg,
7.9,10-5mol) and dry diisopropy1amine (DIPA, 1.4 m1) in anhydrous
DME (14 ml) was kept at 75°C for 18 h. Water (3Om1)was added to
the cooled solution and the lnixture was extracted with chloroform
(3 x 20 m1). The combined organic phase was dried over anhydrous
MgS04, concentrated in vacuo, and the residue was separated over
column chromatography on silica gel (hexane/ether/CHC13 3: 1: 1) to
give 23 (510 mg, 50%) as a solid; m.p. 110°C; (Found: M+, 231.0687.
CI6H9NO requires M, 231.0684);
~ (270 MHz, CDC13) 7.50-7.71
(3H, m), 7.65 «2H, d, 3J = 9.2 Hz), 7.69 (2H, d, 3J = 9.2 Hz),
7.96 (lH, m), 10.59 (lH, s, CHO); MS (EI, 70 eV) m/z (%) 231 (M+)
(4.7).
Ethoxy 3-(4'-cyano-diphenylacetylen-2-yl)acrylate (24): A lnixture
of23 (176 mg, 0.76 mmo1) and ethoxycarbonylmethylidenetripheny1-
phosphorane (424 mg, 1.22 mmo1) in CHC13 (1.5 m1) was placed
into a beaker closed with Saran Wrap® and was heated in an oven at
100°C for 30 min. Direct column chromatography of the mixture on
silica gel (hexane/ether/CHC13 5: 1: 1) gave 24 (89%) as a solid; m.p.
118°C; (Found: M+, 301.1106. C2oHI5N02 requires M, 301.1103); B
H
(270 MHz, CDC13) 1.36 (3H, t, 3J= 7.0 Hz, CH3), 4.29 (2H, q, 3J=
7.0 Hz, OCH2), 6.56 (lH, d, 3J= 15.9 Hz), 7.36-7.70 (8H, m), 8.25
(lH, d, 3J= 15.9 Hz); Be (67.8 MHz, CDC13) 14.3,91.2,93.5,111.8,
118.4, 120.2, 122.9, 126.3, 127.7, 129.4, 129.8, 132.0 (2C), 132.1
(2C), 133.0, 136.1, 142.0, 166.7; MS (EI, 70 eV) m/z (%) 301 (M+)
(59),273 (41),227 (87), 130 (100).
Cyclisation of 24 in presence of Pt(PPhJJ4: A lnixture of 24 (133
mg, 0.44 mmo1) and Pt(PPh3)4 (31 mg, 2.5-10-5 mol) in mesity1ene
(3 m1) was heated at 135°C for 16 h. The resulting mixture was
subjected directly to column chromatography (hexane/ether/CHC13
7: 1: 1) to give 1-(Z)-Ethoxycarbonylmethy1ene-2-(4-cyanopheny1)-
1H-indene (25) (7 mg, 5%) as an orange-red slowly crystallising
solid; (Found: M+, 301.1104. C2oHI5N02 requires M, 301.1103);
vrnax(KEr/cm-l) 3018, 2965, 2208, 1715, BH (270 MHz, CDC13) 1.34
(3H, t, 3J= 7.0 Hz), 4.31 (2H, q, 3J= 7.0 Hz, OCH2), 6.25 (lH, s),
6.97 (lH, s), 7.26-7.36 (3H, m), 7.49 (2H, d, 3J= 8.6 Hz), 7.73 (2H,
d, 3J= 8.6 Hz), 8.60 (lH, d, 3J= 7.8 Hz); MS (EI, 70 eV) m/z (%)
301 (M+) (10), 227 (15), 153 (39); 1-(Z)-(4-cyanopheny1)methy1ene-
2-ethoxycarbony1-1H-indene (26a) (31 mg, 23%) as a yellow-orange
solid; m.p. 152°C; (Found: M+, 301.1105. C2oHI5N02 requires M,
301.1103); vrnax(KBr/cm-l ) 2960, 2210, 1720; ~ (270 MHz, CDC13)
1.41 (3H, t, 3J= 7.0 Hz, CH3), 4.35 (2H, q, 3J= 7.0 Hz, OCH2), 7.06-
7.30 (3H, m), 7.42 (lH, d, 3J = 7.6 Hz), 7.64 (2H, d, 3J = 8.4 Hz),
7.74 (2H, d, 3J= 8.4 Hz), 7.75 (lH, s), 8.42 (lH, s); Be (67.8 MHz,
CDC13) 14.4, 60.4, 111.8, 118.7, 123.6, 128.0, 128.8, 129.8 (2C),
130.0, 132.3 (2C), 134.8, 134.9, 135.8, 140.6, 141.5, 141.7, 141.9,
164.5; MS (EI, 70 eV) m/z (%) 301 (M+) (100), 256 (61), 246
(38), 228 (77), 202 (41); (Found: C, 79.82; H, 5.00; N, 4.77%.
C2oHI5N02 requires, C, 79.72; H, 5.02; N, 4.65%); and 1-(E)-(4-
cyanopheny1)methy1ene-2-ethoxycarbony1-1H-indene (26b) (10 mg,
(Cqual), 13~.7 (C~lll!l)'136.0 (CH~, 1~2.1 (Cq~l)' 142.9 (CH), 165.3
(Cqual>CO), MS ~El, 70 eV) m/z (Yo) - 351 (M ) (5.9),249 (9.9).
17-Bromo-16-ethoxycarbonylethenylestra-1,
3, 5(1 0), 16-tetraen-
3-01 (20): A mixture of 19 (145 mg, 0.40 mmo1) and ethoxy-
carbonylmethylidenetripheny1phosphorane (224 mg, 0.64 mmo1) in
chloroform (1.5 ml) was placed into a beaker closed with Saran Wrap®
and was heated in an oven at 100°C for 1 h 40 min. Direct column
chromatography of the cooled reaction mixture on silica gel (hexane/
CHC13/ether3:2:2) gave 20 (131 mg, 76%); (Found: MH+, 431.1216.
C23H280379Brequires MH, 431.1222 [FAB]); vrnax(KEr/em-l ) 3400-
2960 (bs, OH), 1715, 712; ~ (270 MHz, CDC13)0.90 (3H, s, CH3), 1.32
(3H, t, 3J = 7.0 Hz), 1.45-2.40 (lOH, m), 2.45 (lH, dd, 2J = 14.6 Hz,
3J = 6.5 Hz), 2.86 (2H, m), 4.23 (2H, q, 3J = 7.0 Hz), 4.58 (lH, s, OH),
5.91 (lH, d, 3J = 15.7 Hz), 6.58 (lH, d, 4J = 2.7 Hz), 6.63 (lH, dd,
3J= 8.4 Hz, 4J= 2.7 Hz), 7.14 (lH, d, 3J= 8.4 Hz), 7.58 (lH, d, 3J=
15.7 Hz); Be (67.8 MHz, CDC13)14.3, 15.5,26.1,27.1,29.4,31.0,34.7,
37.4, 44.2, 50.9, 53.3, 60.5, 112.7, 115.3, 120.4, 126.2, 132.3, 135.9,
138.0,138.5,143.8,153.4,167.1; MS (FAB, 3-nitrobenzy1 alcohol) m/z
(%) = 433 ([8IBr]MH+)(0.9), 431 (r9Br]MH+) (1.2).
8%) as
a slowly crystallising yellow-orange oil; (Found: M+,
301.1107. C2oHI5N02 requires M, 301.1103); vrnax(neat/em-I) 2960,
2203, 1710; ~ (270 MHz, CDC13) 0.94 (3H, t, 3J = 7.3 Hz, CH3),
3.82 (2H, q, 3J = 7.3 Hz, OCH2), 7.34-7.71 (lOH, m); MS (EI, 70
eV) m/z (%) 301 (M+) (92), 273 (16),256 (48),228 (64), 84 (100).
The authors thank Prof. Dr. I. Mochida and Prof. Dr. S.-H.
Yoon of Kyushu University for generous gifts ofCNF [CN28-
580°C, HCI treated]. The authors thank Mr K. Umeno for the
preparation of 4-cyanophenylacetylene and Ms Y. Tanaka for
the mass spectroscopic measurements. Elemental analysis
was carried out at the Centre of Analysis, Kyushu University,
Hakozaki Campus. The work was partially carried out within
the framework of a CREST program. Financial support from
the Japan Science and Technology Corporation (JST) is
gratefully acknowledged.
17-Phenylethynyl-16-ethoxycarbonylethenylestra-1,3,5(10),
16-
tetraen-3-01 (21): mixture of 20 (128 mg, 0.30 mmo1),
A
pheny1acety1ene (0.15 ml, 141 mg, 1.38 mmo1), Pd(PPh3hC12
(5 mg, 7'10-6mol), CuI (1 mg, 5.2'10-6 mol) and dry diisopropy1amine
(DIPA, 0.15 ml) in anhydrous DME (3 ml) was kept at 70°C for
19 h. Column chromatography of the residue on silica gel (hexane/
ether/CHC13 1.5: 1: 1) gave 21 (80 mg, 60%) as a colourless solid;
m.p. 234°C; (Found: MH+, 453.2435. C31H3303 requires MH,
453.2430 [FAB]); vrnax(KBr/cm-l ) 3400 - 2960 (bs, OH), 1710,755,
732; ~(270MHz, CDC13)0.97 (3H,s,CH3), 1.32 (3H, t, 3J=7.3 Hz),
1.45-2.43 (lOH, m), 2.55 (lH, dd, 2J = 15.1 Hz, 3J = 6.5 Hz), 2.86
(2H, m), 4.25 (2H, q, 3J = 7.3 Hz), 4.62 (lH, s, OH), 5.91 (lH, d,
3J= 15.7 Hz), 6.58 (lH, d, 4J= 2.7 Hz), 6.64 (lH, dd, 3J= 8.6 Hz,
4J= 2.7 Hz), 7.16 (lH, d, 3J= 8.6 Hz), 7.33-7.36 (3H, m), 7.50-7.54
(2H, m), 7.84 (lH, d, 3J = 15.7 Hz); Be (67.8 MHz, CDC13) 14.3,
16.5,26.4,27.6,29.4,31.1,34.5,37.5,44.2,50.0,54.2,60.4,83.6,
Received 23 September 2008; accepted 3 October 2008
Paper 08/0187 doi: 10.3184/030823408X375214
Published online: 12 December 2008
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