Transition metal control in the reaction of alkyne-substituted phenyl iodides with terminal alkynes: Sonogashira coupling vs cyclic carbopalladation

Article abstract of DOI:10.1016/S0040-4020(02)01154-7

Reaction between terminal alkynes and phenyl iodides bearing a tethered alkyne unit can be effectively controlled by the nature of a transition metal catalyst. Whereas the use of Pd(0)/Cu(I) promotes the expected Sonogashira coupling to give phenyl alkyne

Full text of DOI:10.1016/S0040-4020(02)01154-7

Tetrahedron 58 (2002) 9007–9018
Transition metal control in the reaction of alkyne-substituted
phenyl iodides with terminal alkynes: Sonogashira coupling
vs cyclic carbopalladation
ˇ
Filip Teply, Irena G. Stara, Ivo Stary, Adrian Kollarovic, David Saman and Pavel Fiedler
*
*
´
´
´
´
ˇ
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo n. 2,
166 10 Prague 6, Czech Republic
Received 14 March 2002; revised 23 August 2002; accepted 12 September 2002
Abstract—Reaction between terminal alkynes and phenyl iodides bearing a tethered alkyne unit can be effectively controlled by the nature
of a transition metal catalyst. Whereas the use of Pd(0)/Cu(I) promotes the expected Sonogashira coupling to give phenyl alkynes, the
absence of the copper co-catalyst triggers a palladium-mediated cyclisation providing 1,2-dihydroacenaphthylene, 1H,3H-benzo[de]iso-
chromene, (1Z)-1-(2-propynylidene)-2,3-dihydro-1H-indene and (4E)-4-(2-propynylidene)-3,4-dihydro-1H-isochromene derivatives. In the
latter Pd-catalysed two-component process, the product distribution depends on the structure of alkyne-substituted phenyl iodides, terminal
alkynes and secondary amines used as solvents. The proposed reaction mechanism reflects a competitive formation of intermediary s-
(acetylide) vs p-alkyne Pd(II) complexes. q 2002 Elsevier Science Ltd. All rights reserved.
1. Introduction
3 with terminal alkynes whose outcome may switch from
phenyl alkynes 4 to phenyl enynes 5 and/or acenaphthylene
derivatives 6 depending on the nature of a transition metal
catalyst used as well as on the structure of reactants and
amine solvents (Scheme 2).
Transition metal-catalysed cascade reactions belong to the
powerful tools of contemporary organic synthesis. They
allow a considerable increase in the molecular complexity
in a single operation and usually proceed with excellent
chemo-, regio- and stereoselectivity.1,2 Multicyclisations of
unsaturated substrates, comprising an alkene/alkyne inser-
tion into the Pd–C bond as a relay step, are central to such
effective processes.2
2. Results
2.1. Synthesis of model compounds
Our recent studies on the aryl halide–alkyne coupling,3
related to the synthesis of molecules with helical chirality,4
revealed the Pd-catalysed cascade reaction of naphthyl
iodide 1 affording the acenaphthylene derivative 2
(Scheme 1).3a
The model compounds 11, 12, 14–17 were prepared from
the commercially available o-iodo benzyl alcohol 7 or from
In context of our continuing interest in novel syntheses of
aromatics, we describe herein the reaction of phenyl iodides
Scheme 1.
Keywords: alkynes; aryl halides; coupling reactions; cyclisation.
*
Corresponding authors. Tel.: þ420-2-20183-315; fax: þ420-2-
33331733; e-mail: stary@uochb.cas.cz, stara@uochb.cas.cz.
Scheme 2.
0040–4020/02/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(02)01154-7

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9008
Scheme 3. (a) PBr3 (1.8 equiv.), THF, 08C, 30 min; (b) CBr4 (2.4 equiv.), PPh3 (2.4 equiv.), CH3CN, rt, 10 min; (c) LiCH2CuCTIPS (1.1 equiv.), THF,
2788C, 1 h; (d) NaH (1.4 equiv.), DMF, 08C, 45 min, then BrCH2CuCH (1.5 equiv.), 08C, 30 min; (e) NaH (1.1 equiv.), THF, 08C, 1.5 h, then
BrCH2CuCCH3 (1.2 equiv.), 08C to rt, 68 h; (f) LDA (1.0 equiv.), THF, 2788C, 1 h, then an electrophile added; (g) TIPSCl (1.0 equiv.), 2788C to rt
overnight; (h) TMSCl (1.0 equiv.), 2788C to rt overnight; (i) CH3I (1.0 equiv.), 2788C to rt overnight.
its easily accessible methoxy derivative 83a (Scheme 3).
Bromination of 7 and 8 afforded benzyl bromide 9 and 10
that, on reaction with LiCH2CuCTIPS generated in situ
from triisopropyl(1-propynyl)silane and n-butyllithium,
provided smoothly 3-butynylbenzene 11 and 12, respec-
tively. Benzyl 2-butynyl ether 14 was synthesized directly
from 7 by alkylation of a corresponding alkoxide with
1-bromo-2-butyne. Similarly, alkylation of 8 with propargyl
bromide gave 13, allowing the introduction of appropriate
substituents at the terminus of the tethered alkyne by
quenching a corresponding acetylide with electrophiles. As
n-butyllithium failed to deprotonate selectively the terminal
alkyne in 13 (a halogen/lithium exchange proceeded far
more rapidly), LDA cleanly generated acetylide that, on a
subsequent reaction with TIPSCl, TMSCl or CH3I,
furnished 15–17 with preserved iodine.
Table 1.
Entry
Acetylene (R, equiv.)
Pd(PPh3)4 (mol%)
CuI (mol%)
Cond. (8C, h)
Products (yield, %)a
18
19
20
1
2
3
4
5
6
7
8
TIPS, 1.0
TIPS, 1.0
TMS, 1.2
TMS, 1.2
Ph, 1.0
Ph, 1.0
nBu, 1.0
nBu, 1.0
5
5
5
5
5
5
5
5
10
–
10
–
10
–
10
–
rt, 0.3
80, 22
80, 1
18a (70)
18b (92)
18c (85)
18d (85)
No rxnb
19a (72)
19b (30)
80, 1
rt, 0.1
80, 22
rt, 0.2
80, 22
20 (15)
Complex mixturec
a
Isolated.
A 59% recovery of 11.
The starting material was consumed and a complex mixture of lipophilic products formed.
b
c

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9009
2.2. Phenyl–alkynyl coupling vs cyclic carbopalladation
amount (cf. Table 2, entry 3 and 4). Furthermore, on going
from the bulky TIPS group in 15 to smaller TMS in 16, the
partly cyclised phenyl enyne 27 was exclusively produced
in high yield (cf. Table 2, entry 3 and 5). Regardless of what
amine had been used as a solvent, the close substrates 17 and
14 both bearing the CH3-terminated alkyne unit gave the
partly cyclised phenyl enyne 28 and 29, respectively, in
moderate yields (Table 2, entry 6 and 7).
Initially, on treatment of phenyl iodide 11 with TIPS–
CuCH under Pd(0)/Cu(I) catalysis,5 the expected product
of aryl–acetylene coupling 18a was formed in good yield
(Table 1, entry 1). Omitting the copper(I) co-catalyst,6 no
significant conversion took place even after a prolonged
reaction period and a substantial part of the educt 11 was
recovered (Table 1, entry 2). These results demonstrated
the remarkable accelerating effect of the Cu(I) salt on the
Pd(0)-promoted aryl–alkynyl coupling.
3. Discussion
By contrast, the replacement of the TIPS protecting group
by TMS one in a terminal alkyne resulted in a dramatic
change of the course of the reaction. Whereas the
Pd(0)/Cu(I)-mediated coupling of 11 with TMS–CuCH
proceeded ‘ordinarily’ to give phenylacetylene 18b (Table
1, entry 3), the use of Pd(0) alone led unexpectedly to the
acenaphthylene derivative 19a in good yield (Table 1, entry
4). Hence, the exclusive formation of 19a revealed that
a two-component palladium-catalysed cascade process
operates in the reaction and that the tethered alkyne can
participate easily in it. Similarly, the use of Ph–CuCH
under Pd(0)/Cu(I) catalysis gave clearly rise to the coupled
product 18c (Table 1, entry 5) and the reaction in the
absence of Cu(I) tended to afford acenaphthylene 19b along
with the minor partly cyclised phenyl enyne 20 (Table 1,
entry 6). For 1-hexyne the Pd(0)/Cu(I)-mediated coupling
furnished 18d (Table 1, entry 7) while catalysis by Pd(0)
alone catalysis led to a complex mixture (Table 1, entry 8).
To rationalise the behaviour of the reaction, we propose the
following general mechanism (Scheme 4).7
Oxidative addition of a Pd(0) species to phenyl iodide A
provides the s-arylpalladium(II) intermediate B which
represents a common starting point for three pathways.
Consecutively, its fate depends on the presence or absence
of a Cu(I) salt. Under Pd(0)/Cu(I) catalysis (cycle 1), the fast
Cu(I)/amine-assisted coordination of the terminal alkyne C
to Pd(II) dominates to generate the s-alkynylpalladium(II)
complex D that after reductive elimination produces the
coupled phenylacetylene E leaving a tethered alkyne moiety
untouched.
Alternatively, in the absence of the Cu(I) co-catalyst,
s-arylpalladium B inserts a tethered alkyne unit to form the
s-vinylpalladium(II) intermediate F (5 or 6-exo dig
cyclisation). Here, the reaction can follow two distinct
pathways. Firstly (cycle 2), insertion of the external alkyne
C provides the new s-vinylpalladium(II) intermediate G
that undergoes an intramolecular electrophilic palladation
of an aromatic system8,9 to create the cationic sigma
complex H. A base-assisted extrusion of HI gives the
palladacycle I that after a reductive elimination provides
the acenaphthylene derivative J. Secondly (cycle 3),
s-vinylpalladium F may also enter the coupling route that
affords, via the palladium(II) acetylide intermediate K,
enyne L.
2.3. Scope of cyclic carbopalladation
To understand structural requirements of the Pd(0)-cata-
lysed cyclisation in the absence of the Cu(I) co-catalyst, the
reaction between the various alkyne-substituted phenyl
iodides 11, 12, 14–17 and a terminal alkyne or its
isoelectronic counterpart was investigated (Table 2).
Standard reaction conditions (catalytic amount of
Pd(PPh3)4, diisopropylamine unless noted otherwise,
808C) were used throughout this study.
The mechanistic scheme outlined above (Scheme 4)
comprises two key crossings that reflect, under kinetic
conditions, a competitive formation of a palladium(II)
acetylide s-complex or a palladium(II) acetylene p-com-
plex from an aryl- or vinylpalladium(II) intermediate and an
external or tethered alkyne (Eq. (1)).
On treatment of 11 with trimethylsilyl cyanide, the tethered
alkyne did not participate in the reaction at all and instead a
partial replacement of iodine by cyanide took place to give
21 in moderate yield (Table 2, entry 1). Hereafter, we paid
attention only to the reactions of phenyl iodides with
trimethylsilyl acetylene that has been shown to be superior
among other terminal alkynes in the cyclisation reaction
(see Table 1). The CH3O-substituted phenyl iodide 12
afforded acenaphthylene 22 as a sole product in good yield,
in accord with the outcome of the cascade reaction of the
parent unsubstituted derivative 11 (cf. Table 2, entry 2 and
Table 1, entry 4). Similarly, compound 15 with a three-atom
tether containing oxygen provided benzo[de]isochromene
23 in moderate yield together with its minor regioisomer 24
and the partly cyclised phenyl enyne 25 (Table 2, entry 3).
Surprisingly, when replacing diisopropylamine by piperi-
dine in the reaction of 15, a dramatic effect on the product
distribution was observed. In this case the partly cyclised
phenyl enyne 25 prevailed along with the minor Sonogashira-
type phenyacetylene 26 while the cascade reaction product
benzo[de]isochromene 24 was formed only in a very small
ð1Þ
In the presence of a Cu(I) co-catalyst, the formation of the
palladium(II) acetylide s-complex is a considerably faster
process that is almost invariant under structural changes of
reactants and terminates a cascade reaction (Scheme 4,
cycle 1; see also Table 1, entries 1, 3, 5, 7). Under exclusion
of the Cu(I) co-catalyst, on the other hand, the generation of
the palladium(II) acetylene p-complex may prevail
(Scheme 4, cycle 2 and 3; see also Table 1, entries 4, 6
and Table 2, entries 2–7). It is an essential relay step in the

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
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Table 2.
Entry
Educt
Reagent (equiv.)
TMS–CN (1.6)
Cond.a
Products (yield, %)b
1
2
iPr2NH 2.5 h
(43)c
(72)
TMS–CuCH (1.2)
TMS–CuCH (1.4)
iPr2NH 16 h
3
iPr2NH 1.5 h
(55)d
(10)
(9)
4
TMS–CuCH (2.6)
25 (56)
(30)
24 (5)
5
TMS–CuCH (1.3)
iPr2NH 1.5 h
(97)
6
TMS–CuCH (2.8)
iPr2NH 10 h
(37)
(47)
7
TMS–CuCH (2.0)
Piperidine 4 h
a
Pd(PPh3)4 (5 mol%), 808C.
Isolated.
A 46% recovery of 11.
A 22% recovery of 15.
b
c
d

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9011
Scheme 4.
Figure 1.

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9012
cascade reaction being highly susceptible to the structural
features of reactants. If the R group in the vinylpalladium(II)
intermediate F is large the cycle 2 dominates and, vice
versa, if R is small the cycle 3 is preferred (Scheme 4; cf.
Table 2, entries 3, 5–7). In other words, the acetylide
s-complex i is formed preferentially unless a sterically
less congested acetylene p-complex ii is favoured in this
specific case (Fig. 1). Finally, the reaction outcome can be
influenced also by the terminal alkyne structure as well as
by the solvent but these effects remain unclear.
from calcium hydride under reduced pressure and stored
˚
over 4 A molecular sieves. TLC was performed on Silica gel
60 F254-coated aluminium sheets (Merck) and spots were
detected by the solution of Ce(SO4)2·4H2O (1%) and
H3P(Mo3O10)4 (2%) in sulfuric acid (10%). Flash chroma-
tography was performed on Silica gel 60 (0.040–0.063 mm
or ,0.063 mm, Merck). Semipreparative HPLC was carried
out on a silica gel column (Partisil M9, Whatman 10/50,
500 mm£10 mm; sample injections on a 10–20 mg scale)
using a refractometric detector.
Method A. A Schlenk flask was charged with aryl iodide
(1.0 mmol), Pd(PPh3)4 (5 mol%), CuI (10 mol%) and
flushed with argon. Diisopropylamine (10–15 ml) was
added and the reaction mixture was briefly heated under
stirring to 40–508C. (Trimethylsilyl)-, (triisopropylsilyl)-,
phenyl-, or butylacetylene (1.0–1.2 mmol, 1.0–1.2 equiv.)
was added and the reaction mixture was stirred at rt or 808C
for 0.1–1 h until the reaction composition did not change
(monitored by TLC). The precipitate was filtered off and
washed with petroleum ether (2£2 ml). The combined
fractions were evaporated to dryness in vacuo and the
residue was chromatographed on silica gel to obtain the
product.
4. Conclusion
In summary, we have observed a striking dichotomy in the
reaction of alkyne-substituted phenyl iodides with terminal
alkynes depending on the catalyst system used. Under the
Pd(0)/Cu(I) catalysis, intermolecular aryl–alkynyl coupling
(Sonogashira reaction) has exclusively proceeded regardless
of the presence of an tethered alkyne being disposed to
participate in it. By contrast, when the Cu(I) co-catalyst is
omitted, the adjacent alkyne can take part in the favoured
intramolecular 5 or 6-exo dig carbopalladation that may
be relayed by another alkyne insertion or terminated by
alkenyl–alkynyl coupling. Hence, Cu(I) strongly supports
the intermolecular coordination of terminal alkyne to an
arylpalladium(II) species in an acetylide s-complex fashion
while exclusion of Cu(I) means this process may compete
with the intramolecular formation of an acetylene p-com-
plex depending on the structure of reactants and amine
solvents.
Method B. A Schlenk flask was charged with aryl iodide
(1.0 mmol), Pd(PPh3)4 (5 mol%) and flushed with argon.
Solvent (diisopropylamine or piperidine, 10–15 ml) was
added and the reaction mixture was briefly heated under
stirrig to 40–508C. (Trimethylsilyl)-, (triisopropylsilyl)-,
phenyl-or butylacetylene (1.0–2.8 mmol, 1.0–2.8 equiv.)
was added and the reaction mixture was stirred at 808C for
1–22 h until the reaction composition did not change
(monitored by TLC). The precipitate was filtered off and
washed with petroleum ether (2£2 ml). The combined
fractions were evaporated to dryness in vacuo and the
residue was chromatographed on silica gel to obtain the
product.
5. Experimental
5.1. General
Melting points were determined on a Kofler hot-stage
apparatus and are uncorrected. 1H NMR spectra were
measured at 499.8 or 200.0 MHz, 13C NMR spectra at
125.7 MHz, in CDCl3 with TMS as an internal standard.
Chemical shifts are given in d-scale, coupling constants J
5.1.1. 1-(Bromomethyl)-2-iodobenzene 9. Phosphorus
tribromide (1.2 ml, 12.63 mmol, 1.8 equiv.) was added at
08C to benzyl alcohol 7 (5 g, 21.36 mmol) in THF (25 ml)
under nitrogen and the mixture was stirred at 08C for
30 min. The solvent was evaporated in vacuo and the
residue was purified by flash chromatography on silica gel
(petroleum ether) to get benzyl bromide 9 (6.05 g, 95%) as a
white crystalline material, mp 54–558C (petroleum ether).10
are given in Hz. HMBC experiments were setup for JC–H
¼
5 Hz. For correct assignment of both H and 13C NMR
spectra of key compounds, the HCOSY and HMQC
experiments were performed. For all the other compounds,
the general semi-empirical equations were applied to the
chemical shift assignments. IR spectra were measured in
CHCl3. EI MS spectra were determined at an ionizing
voltage of 70 eV, m/z values are given along with their
relative intensities (%). HR MS spectra were obtained by the
EI technique. GC MS analyses were carried out on a DB-5
column (0.25£30 m£0.25 mm). All reactions were per-
formed under argon unless noted otherwise. Reagent grade
materials purchased from Sigma-Aldrich, Fluka, Merck,
Acros Chimica (7) and Avocado were used as received. The
compound 8 was prepared according to the literature
procedure.3a THF was freshly distilled from sodium/
benzophenone under nitrogen; diisopropylamine and piperi-
dine were distilled from calcium hydride under argon and
degassed by three freeze–pump–thaw cycles before use;
acetonitrile was distilled from calcium hydride under argon
1
1
Caution: lachrymator! H NMR (200 MHz): 4.60 (s, 2H,
CH2), 6.99 (dt, 1H, J¼7.5, 1.7 Hz, 4-H), 7.34 (dt, 1H, J¼
7.5, 1.2 Hz, 5-H), 7.48 (dd, 1H, J¼7.6, 1.8 Hz, 6-H), 7.86
(dd, 1H, J¼7.9, 1.2 Hz, 3-H). EI MS: 296 (Mþz, 18), 217
(100), 90 (38), 63 (9), 39 (5).
5.1.2. 2-(Bromomethyl)-1-iodo-4-methoxybenzene 10.
Triphenylphosphine (10.02 g, 38.18 mmol, 2.4 equiv.) in
dry acetonitrile (30 ml) was added dropwise at rt to the
solution of benzyl alcohol 8 (4.20 g, 15.90 mmol) and
tetrabromomethane (12.68 g, 38.22 mmol, 2.4 equiv.) in dry
acetonitrile (40 ml) under nitrogen. After stirring at rt for
10 min, the reaction mixture was filtered, the precipitate was
washed with petroleum ether–ether (95:5), and the filtrate
was evaporated to dryness in vacuo. Flash chromatography
on silica gel (petroleum ether–ether 95:5) provided benzyl
˚
and stored over 4 A molecular sieves; DMF was distilled

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9013
bromide 10 (4.58 g, 88%) as a white crystalline solid, mp
106–1078C (petroleum ether–ether 95:5). IR: 3068 vw,
3030 vw, 2964 w, 2940 w, 2909 w, 2838 w, 1593 m, 1567
m, 1474 vs, 1464 m (sh), 1443 w, 1439 m, 1412 m, 1313 s,
1296 m, 1280 s, 1239 vs, 1173 m, 1168 m, 1152 w, 1102 w,
1052 m, 1045 m, 1011 m, 928 w, 875 w, 818 w, 807 w, 647
w, 590 m, 571 m, 528 w, 440 vw. 1H NMR (500 MHz): 3.80
(s, 3H, CH3), 4.55 (s, 2H, CH2), 6.60 (dd, 1H, J¼8.8,
3.0 Hz, 5-H), 7.03 (d, 1H, J¼3.1 Hz, 3-H), 7.70 (d, 1H,
J¼8.8 Hz, 6-H). 13C NMR: 38.7 (t, CH2), 55.5 (q, CH3),
88.3 (s, C-1), 116.2 (d, C-5), 116.4 (d, C-3), 140.5 (d, C-6),
141.0 (s, C-2), 160.2 (s, C-4). EI MS: 326 (Mþz, 26), 247
(100), 120 (25), 91 (9), 77 (11), 51 (12). HR EI MS:
calculated for C8H8BrIO 325.8803; found 325.8820.
CH2CuC), 88.7 (s, C-2), 107.4 (s, CH2CuC), 113.9 (d,
C-6), 116.3 (d, C-4), 139.8 (d, C-3), 143.9 (s, C-1), 159.9 (s,
C-5). EI MS: 442 (Mþz, 10), 399 (100), 371 (9), 351 (15),
329 (9), 273 (29), 247 (9), 229 (30), 215 (9), 201 (18), 172
(11), 121 (14), 89 (7), 73 (8), 59 (18), 43 (11). HR EI MS:
calculated for C20H31IOSi 442.1189; found 442.1191.
5.1.5. 1-Iodo-4-methoxy-2-[(2-propynyloxy)methyl]ben-
zene 13. Alcohol 8 (555 mg, 2.24 mmol) in dry DMF (2 ml)
was added dropwise to sodium hydride (80% suspension in
mineral oil, 91 mg, 3.03 mmol, 1.4 equiv.) in dry DMF
(1 ml) at 08C. After stirring at 08C for 45 min, propargyl
bromide (300 ml, 3.37 mmol, 1.5 equiv.) was added and the
mixture was stirred at 08C for 30 min. The reaction mixture
was diluted with water and extracted with diethyl ether (2£).
The ethereal fractions were combined, washed with water
(1£) and dried over anhydrous Na2SO4. The solvent was
removed in vacuo and the crude product was purified by
flash chromatography on silica gel (hexane–diethyl ether
100:0 to 90:10) to obtain alkyne 13 (476 mg, 71%) as a
white amorphous solid. IR: 3307 s, 3075 w, 2841 m, 2120
w, 1590 s, 1570 s, 1469 vs, 1442 s, 1416 m, 1405 m, 1386 m,
1356 m, 1297 vs, 1275 s, 1257 s, 1237 vs, 1165 s, 1119 s,
1095 vs, 1086 vs (sh), 1056 s, 1009 s, 859 m, 816 m, 678 m,
5.1.3. [4-(2-Iodophenyl)-1-butynyl](triisopropyl)silane
11. n-Butyllithium (1.6 M in hexanes, 1.23 ml, 1.97 mmol,
1.1 equiv.) was added at 2788C to 1-(triisopropylsilyl)-1-
propyne (0.48 ml, 1.98 mmol, 1.2 equiv.) in dry THF
(6 ml). After stirring at 2788C for 2 h, benzyl bromide 9
(510 mg, 1.73 mmol) in dry THF (9 ml) was added and the
mixture was stirred at 2788C for 1 h. The reaction mixture
was allowed to reach rt and solvents were evaporated in
vacuo. Flash chromatography on silica gel (petroleum ether)
afforded alkyne 11 (706 mg, 99%) as an oil. IR: 3065 w,
2958 s, 2944 s, 2891 m, 2865 vs, 2171 m, 1588 w, 1563 w,
1466 s, 1453 w (sh), 1436 w, 1429 w (sh), 1383 w, 1367 w,
1338 w, 1322 vw, 1285 vw, 1255 w, 1243 w, 1161 vw, 1112
vw, 1073 w, 1045 w, 1039 w, 1012 m, 996 m, 943 vw, 883
m, 678 m, 661 m, 530 w, 440 w. 1H NMR (500 MHz): 1.03
(m, 21H, 3£(CH3)2CH), 2.57 (t, 2H, J¼7.3 Hz, CH2CuC),
2.95 (t, 2H, J¼7.3 Hz, CH2Ar), 6.89 (td, 1H, J¼7.6, 1.7 Hz,
4-H), 7.25 (td, 1H, J¼7.5, 1.3 Hz, 5-H), 7.31 (dd, 1H, J¼
7.7, 1.7 Hz, 6-H), 7.80 (dd, 1H, J¼7.9, 1.3 Hz, 3-H). 13C
NMR: 11.3 (d, 3£(CH3)2CH), 18.6 (q, 3£(CH3)2CH), 20.5
(t, CH2CuC), 40.0 (t, CH2Ar), 81.4 (s, CH2CuC), 100.3 (s,
C-2), 107.4 (s, CH2CuC), 128.1 (d, C-4), 128.2 (d, C-5),
130.1 (d, C-6), 139.4 (d, C-3), 142.9 (s, C-1). EI MS: 369
((M243)þ, 100), 341 (9), 327 (13), 299 (8), 243 (16), 209
(34), 199 (20), 171 (13), 153 (97), 139 (14), 125 (34), 111
(31), 97 (53), 83 (64), 59 (25), 43 (17). HR EI MS:
calculated for C16H22ISi (M2C3H7) 369.0536; found
369.0517.
1
635 s, 590 m, 548 w. H NMR (500 MHz): 2.50 (t, 1H,
J¼2.4 Hz, HCuC), 3.80 (s, 3H, CH3), 4.27 (d, 2H,
J¼2.4 Hz, HCuCCH2), 4.56 (brs, 2H, CH2Ar), 6.60 (dd,
1H, J¼8.6, 3.1 Hz, 5-H), 7.04 (dt, 1H, J¼3.1, 0.6 Hz, 3-H),
7.67 (d, 1H, J¼8.7 Hz, 6-H). 13C NMR: 55.4 (q, CH3), 57.9
(t, HCuCCH2), 75.0 (t, CH2Ar), 75.3 (d, HCuC), 79.4 (s,
HCuC), 85.9 (s, C-1), 114.6 (d, C-3), 115.6 (d, C-5), 139.6
(d, C-6), 140.8 (s, C-2), 160.1 (s, C-4). EI MS: 302 (Mþz,
84), 261 (9), 248 (28), 233 (4), 175 (18), 145 (90), 121
(100), 102 (18), 91 (32), 77 (26), 63 (28), 51 (18), 39 (27).
HR EI MS: calculated for C11H11IO2 301.9804; found
301.9799.
5.1.6. 1-[(2-Butynyloxy)methyl]-2-iodobenzene 14. Alco-
hol 7 (500 mg, 2.14 mmol) in dry THF (6 ml) was added
dropwise over 5 min to sodium hydride (80% suspension in
mineral oil, 70 mg, 2.32 mmol, 1.1 equiv.) in dry THF
(4 ml) at 08C. After stirring at 08C for 1.5 h, 1-bromo-2-
butyne (350 mg, ca. 230 ml, 2.63 mmol, 1.2 equiv.) was
added and the mixture was stirred at 08C to rt for 68 h. The
precipitate was filtered off, washed with dichloromethane
and the filtrate was evaporated in vacuo to drynes. Flash
chromatography on silica gel (petroleum ether–acetone
95:5) gave alkyne 14 (436 mg, 71%) as an oil. IR: 3061 w,
2954 m, 2924 s, 2856 s, 2245 w, 2233 w (sh), 1588 w, 1566
m, 1466 m, 1439 s, 1386 m, 1273 m, 1156 m, 1114 m, 1085
vs, 1075 vs, 1045 s, 1014 vs, 949 m, 650 w, 530 w, 429 w.
1H NMR (200 MHz): 1.89 (t, 3H, J¼2.2 Hz, CH3), 4.22 (q,
2H, J¼2.2 Hz, CH2CuC), 4.57 (s, 2H, CH2Ar), 6.98 (td,
1H, J¼7.6, 1.5 Hz, 4-H), 7.34 (td, 1H, J¼7.6, 1.5 Hz, 5-H),
7.45 (dd, 1H, J¼7.6, 1.5 Hz, 6-H), 7.82 (dd, 1H, J¼7.6,
1.5 Hz, 3-H). 13C NMR: 3.6 (q, CH3), 58.4 (t, CH2CuC),
74.9 (s, CH2CuC), 75.3 (t, CH2Ar), 83.0 (s, CH2CuC),
98.0 (s, C-2), 128.2 (d, C-5), 129.0 (d, C-6), 129.3 (d, C-4),
132.2 (d, C-3), 140.1 (s, C-1). EI MS: 286 (Mþz, 16), 271
(7), 256 (6), 231 (100), 217 (53), 203 (9), 129 (79), 115 (7),
104 (25), 91 (49), 90 (49), 78 (45), 63 (16), 53 (49), 39 (30).
HR EI MS: calculated for C11H11IO 285.9855; found
285.9868.
5.1.4. [4-(2-Iodo-5-methoxyphenyl)-1-butynyl](triisopro-
pyl)silane 12. The same procedure as described for 11,
starting from n-butyllithium (1.6 M in hexanes, 3.4 ml,
5.44 mmol, 1.2 equiv.), 1-(triisopropylsilyl)-1-propyne
(1.3 ml, 5.43 mmol, 1.2 equiv.), THF (20 ml), 2788C, 2 h,
then benzyl bromide 10 (1.55 g, 4.74 mmol), THF (15 ml),
2788C, 1 h. Flash chromatography on silica gel (petroleum
ether–ether 95:5) furnished alkyne 12 (1.73 g, 82%) as an
oil. IR: 3077 vw, 3065 vw, 2960 vs, 2944 vs, 2922 s, 2892 s,
2866 vs, 2840 m (sh), 2171 s, 1591 m, 1568 s, 1467 vs, 1429
m, 1412 m, 1383 m, 1366 w, 1336 w, 1302 s, 1293 s, 1277 s,
1238 vs, 1173 m (sh), 1162 m, 1112 w, 1072 m, 1056 s,
1043 s, 996 m, 953 w, 884 s, 678 s, 661 s, 593 m. 1H NMR
(500 MHz): 1.03 (m, 21H, 3£(CH3)2CH), 2.56 (t, 2H, J¼
7.3 Hz, CH2CuC), 2.90 (t, 2H, J¼7.3 Hz, CH2Ar), 3.77 (s,
3H, CH3O), 6.51 (dd, 1H, J¼8.7, 3.0 Hz, 4-H), 6.87 (d, 1H,
J¼3.0 Hz, 6-H), 7.66 (d, 1H, J¼8.7 Hz, 3-H). 13C NMR:
11.3 (d, 3£(CH3)2CH), 18.6 (q, 3£(CH3)2CH), 20.4 (t,
CH2CuC), 40.1 (t, CH2Ar), 55.3 (q, CH3O), 81.3 (s,

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9014
5.1.7. {3-[(2-Iodo-5-methoxybenzyl)oxy]-1-propynyl}-
(triisopropyl)silane 15. Lithium diisopropylamide (2 M
solution in THF–heptane–ethylbenzene, 535 ml, 1.07 mmol,
1.0 equiv.) was added dropwise to terminal alkyne 13
(323 mg, 1.07 mmol) in dry THF (3 ml) at 2788C. After
stirring at 788C for 1 h, triisopropylsilyl chloride (230 ml,
1.08 mmol, 1.0 equiv.) was added and the mixture was
stirred at 2788C to rt overnight. The solvents were removed
in vacuo. Flash chromatography on silica gel (petroleum
ether–ether 100:0 to 90:10) afforded silylated alkyne 15
(455 mg, 93%) as an oil. IR: 2959 s, 2944 vs, 2891 s, 2866
vs, 1590 m, 1570 m, 1466 vs, 1443 m, 1416 w, 1405 w, 1383
m, 1367 w, 1352 m, 1297 s, 1275 m, 1255 m, 1237 s, 1193
w, 1165 m, 1118 m, 1088 s, 1056 m, 1029 m, 996 m (sh),
883 s, 816 w, 679 s, 670 s, 589 m, 453 w. 1H NMR
(500 MHz): 1.08–1.10 (m, 21H, 3£(CH3)2CH), 3.79 (s, 3H,
CH3), 4.32 (s, 2H, CuCCH2), 4.59 (t, 2H, J¼0.7 Hz,
CH2Ar), 6.59 (ddt, 1H, J¼8.7, 3.1, 0.6 Hz, 4-H), 7.05 (dt,
1H, J¼3.1, 0.8 Hz, 6-H), 7.66 (d, 1H, J¼8.7 Hz, 3-H). 13C
NMR: 11.2 (d, 3£(CH3)2CH), 18.6 (q, 3£(CH3)2CH), 55.4
(q, CH3), 58.6 (t, CuCCH2), 74.9 (t, CH2Ar), 85.8 (s, C-2),
88.4 (s, SiCuC), 102.9 (s, SiCuC), 114.4 (d, C-6), 115.9
(d, C-4), 141.2 (s, C-1), 160.1 (s, C-5). EI MS: 458 (Mþz,
14), 415 (100), 373 (6), 301 (9), 289 (10), 247 (39), 210
(16), 179 (18), 121 (10), 91 (28), 83 (9), 59 (9), 41 (8). HR
EI MS: calculated for C20H31IO2Si 458.1138; found
458.1111.
to 98:2) afforded the crude product which was purified by
preparative HPLC (petroleum ether–acetone 99:1) to obtain
the methylated alkyne 17 (115 mg, 73%) as an oil. IR: 2230
w, 1590 s, 1571 s, 1468 vs, 1443 s, 1416 s, 1405 m, 1296 vs,
1276 s, 1258 s, 1237 vs, 1193 m, 1165 s, 1117 s, 1088 vs,
1055 s, 1045 s (sh), 816 m, 590 m, 443 w. 1H NMR
(500 MHz): 1.89 (t, 3H, J¼2.4 Hz, CH3CuC), 3.80 (s, 3H,
CH3), 4.23 (q, 2H, J¼2.4 Hz, CuCCH2), 4.53 (t, 2H,
J¼0.7 Hz, CH2Ar), 6.59 (ddt, 1H, J¼8.7, 3.1, 0.6 Hz, 5-H),
7.05 (dt, 1H, J¼3.1, 0.7 Hz, 3-H), 7.66 (d, 1H, J¼8.7 Hz,
6-H). 13C NMR: 3.7 (q, CH3CuC), 55.4 (q, CH3), 58.5
(t, CuCCH2), 74.8 (s, CH3CuC), 75.2 (t, CH2Ar), 83.1
(s, CH3CuC), 85.9 (s, C-1), 114.5 (d, C-3), 115.5 (d, C-5),
139.5 (d, C-6), 141.2 (s, C-2), 160.1 (s, C-4). EI MS: 316
(Mþz, 13), 261 (5), 247 (9), 159 (100), 135 (6), 121 (49), 91
(16), 77 (17), 63 (13), 53 (26), 39 (16). HR EI MS:
calculated for C12H13IO2 315.9960; found 315.9973.
5.1.10. Triisopropyl(4-{2-[(triisopropylsilyl)ethynyl]-
phenyl}-1-butynyl)silane 18a. Method A: 11 (92 mg,
0.220 mmol), Pd(PPh3)4 (13 mg, 0.011 mmol, 5 mol%),
CuI (4 mg, 0.022 mmol, 10 mol%), (triisopropylsilyl)-
acetylene (50 ml, 0.220 mmol, 1.0 equiv.), diisopropyl-
amine (2 ml), rt, 20 min. Flash chromatography on silica
gel (petroleum ether) afforded 18a (73 mg, 70%) as an oil.
IR: 3095 vw, 3069 vw, 2959 s, 2944 s, 2891 m, 2866 vs,
2170 w, 2153 w, 1482 w, 1463 m, 1383 w, 1367 w, 1099 w,
1072 w, 1018 w, 996 m, 883 m, 859 w, 835 w, 678 s, 662 s,
640 m, 460 w. 1H NMR (500 MHz): 1.04 (m, 42H,
6£(CH3)2CH), 2.60 (t, 2H, J¼7.7 Hz, CH2CuC), 3.04 (t,
2H, J¼7.7 Hz, CH2Ar), 7.15 (td, 1H, J¼7.5, 1.5 Hz, 4-H),
7.22 (td, 1H, J¼7.6, 1.4 Hz, 5-H), 7.26 (ddd, 1H, J¼7.7, 1.5,
0.5 Hz, 6-H), 7.46 (ddd, 1H, J¼7.6, 1.4, 0.5 Hz, 3-H). 13C
NMR: 11.3 (d, ((CH3)2CH)3SiCuCCH2), 11.4 (d,
5.1.8. {3-[(2-Iodo-5-methoxybenzyl)oxy]-1-propynyl}-
(trimethyl)silane 16. Lithium diisopropylamide (2 M
solution in THF–heptane–ethylbenzene, 265 ml, 0.530
mmol, 1.0 equiv.) was added dropwise to terminal alkyne
13 (160 mg, 0.530 mmol) in dry THF (3 ml) at 2788C.
After stirring at 2788C for 1 h, trimethylsilyl chloride (68
ml, 0.536 mmol, 1.0 equiv.) was added and the mixture was
stirred at 2788C to rt overnight. The solvents were removed
in vacuo. Flash chromatography on silica gel (petroleum
ether–ether 100:0 to 98:2) afforded silylated alkyne 16
(160 mg, 85%) as an oil. IR: 3074 vw, 2900 m, 2841 m,
2175 w, 1590 m, 1570 m, 1568 s, 1441 m, 1416 m, 1406 m,
1385 m, 1352 m, 1297 s, 1275 s, 1252 vs, 1237 s, 1193 w,
1165 s, 1118 m, 1088 s, 1056 s, 1030 s, 847 vs, 817 m, 701
w, 690 w, 639 w, 440 w. 1H NMR (500 MHz): 0.20 (s, 9H,
(CH3)3Si), 3.80 (s, 3H, CH3), 4.26 (s, 2H, CuCCH2), 4.56
(t, 2H, J¼0.7 Hz, CH2Ar), 6.60 (ddt, 1H, J¼8.6, 3.1, 0.6 Hz,
4-H), 7.05 (dt, 1H, J¼3.1, 0.8 Hz, 6-H), 7.67 (d, 1H,
J¼8.6 Hz, 3-H). 13C NMR: 20.2 (q, (CH3)3Si), 55.4 (q,
CH3), 58.6 (t, CuCCH2), 75.2 (t, CH2Ar), 86.0 (s, C-2),
92.5 (s, SiCuC), 103.2 (s, SiCuC), 114.6 (d, C-6), 115.6
(d, C-4), 139.6 (d, C-3), 141.0 (s, C-1), 160.1 (s, C-5). EI
MS: 374 (Mþz, 20), 247 (16), 217 (100), 202 (13), 121 (39),
91 (7), 83 (8), 73 (25), 59 (13), 43 (5). HR EI MS: calculated
for C14H19IO2Si 374.0199; found 374.0207.
((CH3)2CH)3-SiCuCAr),
18.6
(q,
((CH3)2CH)3-
SiCuCCH2), 18.7 (q, ((CH3)2CH)3SiCuCAr), 21.0 (t,
CH2CuC), 34.4 (t, CH2Ar), 80.7 (s, CuCCH2), 94.6 (s,
CuCAr), 105.1 (s, CuCAr), 108.1 (s, CuCCH2), 122.8 (s,
C-2), 126.1 (d, C-4), 128.3 (d, C-5), 129.2 (d, C-6), 132.8 (d,
C-3), 142.8 (s, C-1). EI MS: 446 (Mþz, 18), 423 (91), 381
(38), 339 (11), 308 (7), 265 (6), 190 (11), 157 (100), 134
(13), 115 (43), 101 (8), 87 (29), 73 (40), 59 (55). HR EI MS:
calculated for C30H50Si2 466.3451; found 466.3440.
5.1.11. Triisopropyl(4-{2-[(trimethylsilyl)ethynyl]phenyl}-
1-butynyl)silane 18b. Method A: 11 (110 mg, 0.26 mmol),
Pd(PPh3)4 (16 mg, 0.014 mmol, 5 mol%), CuI (5 mg,
0.025 mmol, 10 mol%), (trimethylsilyl)acetylene (45 ml,
0.320 mmol, 1.2 equiv.), diisopropylamine (5 ml), 808C,
1 h. Flash chromatography on silica gel (petroleum ether)
afforded 18b (93 mg, 92%) as an oil. IR: 3095 w, 3069 w,
2961 vs, 2944 vs, 2920 vs (sh), 2893 s, 2866 vs, 2170 s,
2155 s, 1599 w, 1581 vw, 1482 s, 1464 s, 1451 s, 1429 w,
1408 w, 1383 m, 1366 w, 1339 w, 1262 m, 1251 vs, 1160 w,
1074 m, 1018 m, 996 s, 947 w, 883 vs, 867 vs, 844 vs, 678 s,
5.1.9. 2-[(2-Butynyloxy)methyl]-1-iodo-4-methoxy-
benzene 17. Lithium diisopropylamide (2 M solution
in THF–heptane–ethylbenzene, 250 ml, 0.500 mmol,
1.0 equiv.) was added dropwise to terminal alkyne 13
(151 mg, 0.500 mmol) in dry THF (3 ml) at 2788C. After
stirring at 2788C for 1 h, methyl iodide (32 ml, 0.514 mmol,
1.0 equiv.) was added and the mixture was stirred at 2788C
to rt overnight. The solvents were removed in vacuo. Flash
chromatography on silica gel (petroleum ether–ether 100:0
1
661 s, 646 s, 604 m, 583 w, 457 m. H NMR (500 MHz):
0.26 (s, 9H, (CH3)3Si), 1.04 (m, 21H, 3£(CH3)2CH), 2.60
(t, 2H, J¼7.7 Hz, CH2CuC), 3.01 (t, 2H, J¼7.7 Hz,
CH2Ar), 7.14 (ddd, 1H, J¼7.6, 7.1, 1.9 Hz, 4-H), 7.22
(ddd, 1H, J¼7.7, 7.1, 1.5 Hz, 5-H), 7.25 (ddd, 1H, J¼7.7,
1.9, 0.7 Hz, 6-H), 7.42 (ddd, 1H, J¼7.6, 1.5, 0.7 Hz, 3-H).
13C NMR: 0.0 (q, (CH3)3Si), 11.3 (d, 3£(CH3)2CH), 18.6
(q, 3£(CH3)2CH), 20.6 (t, CH2CuC), 34.4 (t, CH2Ar), 80.7

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9015
(s, CH2CuC), 98.5 (s, ArCuC), 103.5 (s, ArCuC), 108.2
(s, CH2CuC), 122.4 (s, C-2), 126.2 (d, C-4), 128.5 (d, C-5),
129.1 (d, C-6), 132.2 (d, C-3), 143.0 (s, C-1). EI MS: 382
(Mþz, 16), 367 (3), 339 (75), 297 (16), 265 (5), 255 (16), 237
(6), 223 (10), 195 (41), 183 (9), 157 (11), 134 (16), 129 (14),
101 (25), 73 (100), 59 (95), 43 (33). HR EI MS: calculated
for C24H38Si2 382.2512; found 382.2501.
C-5), 129.07 (d, C-6), 132.04 (d, C-3), 142.25 (s, C-1). EI
MS: 366 (Mþz, 100), 323 (11), 281 (49), 253 (13), 239 (40),
225 (25), 211 (28), 197 (63), 183 (45), 165 (20), 119 (17), 85
(14), 73 (30), 59 (99). HR EI MS: calculated for C25H38Si
366.22743; found 366.2758.
5.1.14. Triisopropyl[5-(trimethylsilyl)-1,2-dihydro-3-
acenaphthylenyl]silane 19a. Method B: 11 (100 mg,
0.24 mmol), Pd(PPh3)4 (15 mg, 0.013 mmol, 5 mol%),
(trimethylsilyl)acetylene (40 ml, 0.280 mmol, 1.2 equiv.),
diisopropylamine (5 ml), 808C, 1 h. Flash chromatography
on silica gel (petroleum ether) afforded 19a (65 mg, 72%) as
an oil. IR: 3066 w, 2947 vs, 2925 s, 2891 m, 2866 s, 1607 w,
1585 w, 1558 w, 1464 m, 1447 w, 1407 w, 1389 w, 1383 w,
1367 w, 1251 s, 1073 w, 995 w, 883 s, 858 s, 838 vs, 690 w,
677 m, 660 m, 649 m, 627 w, 601 w. 1H NMR (500 MHz):
0.43 (s, 9H, (CH3)3Si), 1.12 (d, 18H, J¼7.5 Hz, 3£
(CH3)2CH), 1.56 (septet, 3H, J¼7.5 Hz, 3£(CH3)2CH),
3.34–3.38 (m, 2H, 2-H), 3.42–3.46 (m, 2H, 1-H), 7.30 (dtd,
1H, J¼6.8, 1.4, 0.8 Hz, 8-H), 7.47 (dd, 1H, J¼8.3, 6.9 Hz,
7-H), 7.75 (s, 1H, 4-H), 7.77 (dq, 1H, J¼8.3, 0.9 Hz, 6-H).
13C NMR: 0.1 (q, (CH3)3Si), 11.9 (d, 3£(CH3)2CH), 18.8 (q,
3£(CH3)2CH), 30.1 (t, C-1), 32.5 (t, C-2), 118.9 (d, C-8),
122.9 (d, C-7), 125.0 (s, C-8b), 127.7 (d, C-6), 130.5 (s,
C-8a), 135.5 (s, C-3), 138.3 (s, C-5), 141.8 (d, C-4), 146.8
(s, C-5a), 155.9 (s, C-2a). EI MS: 382 (Mþz, 57), 367 (9),
339 (69), 310 (6), 297 (53), 286 (12), 269 (24), 255 (32), 243
(61), 223 (37), 209 (34), 201 (28), 195 (21), 183 (14), 171
(20), 157 (20), 134 (23), 127 (31), 115 (14), 97 (10), 85 (17),
73 (100), 59 (55), 41 (40). HR EI MS: calculated for
C24H38Si2 382.2512; found 382.2501.
5.1.12. Triisopropyl{4-[2-(phenylethynyl)phenyl]-1-
butynyl}silane 18c. Method A: 11 (110 mg, 0.260 mmol),
Pd(PPh3)4 (16 mg, 0.014 mmol, 5 mol%), CuI (5 mg,
0.027 mmol, 10 mol%), phenylacetylene (30 ml, 0.260 mmol,
1.0 equiv.), diisopropylamine (6 ml), rt, 5 min. Flash
chromatography on silica gel (petroleum ether) afforded
18c (90 mg, 85%) as an oil. IR: 3098 vw, 3084 w, 3064 w,
2958 s, 2944 vs, 2920 s (sh), 2891 m, 2865 vs, 2215 vw,
2170 s, 1601 w, 1572 vw, 1495 m, 1464 m, 1452 m, 1443 w,
1429 w, 1383 w, 1366 w, 1338 w, 1309 vw, 1243 w, 1160
vw, 1070 w, 1027 w, 1018 w, 996 m, 946 w, 917 w, 884 m,
862 w, 844 vw, 690 s, 678 m, 661 m, 622 w, 600 w, 588 w,
1
460 w. H NMR (500 MHz): 1.04 (m, 21H, 3£(CH3)2CH),
2.68 (t, 2H, J¼7.6 Hz, CH2CuC), 3.10 (t, 2H, J¼7.6 Hz,
CH2Ar), 7.20 (td, 1H, J¼7.4, 1.5 Hz, 4-H (–Ar–)), 7.25 (td,
1H, J¼7.5, 1.6 Hz, 5-H (–Ar–)), 7.30 (bdd, 1H, J¼7.6,
1.4 Hz, 6-H (–Ar–)), 7.32–7.38 (m, 3H, 3, 4, 5-H (Ph)), 7.50
(bdd, 1H, J¼7.4, 1.5 Hz, 3-H (–Ar–)), 7.53–7.55 (m, 2H, 2,
6-H (Ph)). 13C NMR: 11.3 (d, 3£(CH3)2CH), 18.6 (q,
3£(CH3)2CH), 20.9 (t, CH2CuC), 34.4 (t, CH2Ar), 80.9 (s,
CH2CuC), 87.8 (s, ArCuCPh), 93.5 (s, ArCuCPh), 108.2
(s, CH2CuC), 122.6 (s, C-2 (–Ar–)), 123.4 (s, C-1 (Ph)),
126.3 (d, C-4 (–Ar–)), 128.2 (d, C-5 (–Ar–)), 128.3 (d, C-4
(Ph)), 128.4 (d, C-3, 5 (Ph)), 129.2 (d, C-6 (–Ar–)), 131.5 (d,
C-2, 6 (Ph)), 132.0 (d, C-3 (–Ar–)), 142.5 (s, C-1 (–Ar–)).
EI MS: 386 (Mþz, 100), 343 (41), 301 (40), 273 (24), 259 (86),
245 (28), 241 (13), 229 (30), 215 (21), 202 (16), 189 (29), 165
(20), 144 (26), 135 (43), 121 (35), 105 (9), 73 (13), 59 (62), 43
(14). HR EI MS: calculated for C27H34Si 386.2430; found
386.2439.
5.2. Reaction of 11 with phenylacetylene in
diisopropylamine to get 19b and 20
Method B: 11 (85 mg, 0.210 mmol), Pd(PPh3)4 (12 mg,
0.010 mmol,
5 mol%),
phenylacetylene
(23 ml,
0.210 mmol, 1.0 equiv.), diisopropylamine (4 ml), 808C,
22 h. Flash chromatography on silica gel (petroleum ether)
afforded acenaphthylene 19b (20 mg, 30%) and more polar
indene 20 (10 mg, 15%) as oils.
5.1.13. {4-[2-(1-Hexynyl)phenyl]-1-butynyl}(triisopropyl)-
silane 18d. Method A: 11 (97 mg, 0.235 mmol), Pd(PPh3)4
(14 mg, 0.0121 mmol, 5 mol%), CuI (5 mg, 0.0263 mmol,
10 mol%), 1-hexyne (28 ml, 0.244 mmol, 1.0 equiv.), diiso-
propylamine (2 ml), rt, 10 min. Flash chromatography on
silica gel (petroleum ether) afforded 18d (74 mg, 85%) as an
oil. IR: 3096 vw, 3069 w, 2960 vs, 2943 vs, 2892 s, 2865 vs,
2227 w, 2170 s, 1599 w, 1485 m, 1464 s, 1452 m, 1430 w,
1382 w, 1366 w, 1339 w, 1328 w, 1160 vw, 1104 w, 1073 w,
1018 w, 996 m, 946 w, 884 s, 678 s, 661 s, 599 w, 587 w,
523 w, 498 w, 418 w. 1H NMR (500 MHz): 0.95 (t, 3H, J¼
7.4 Hz, CH3CH2CH2CH2), 0.98–1.06 (m, 21H, 3£
(CH3)2CH), 1.46–1.53 (m, 2H, CH3CH2CH2CH2), 1.58–
1.64 (m, 2H, CH3CH2CH2CH2), 2.44 (t, 2H, J¼7.0 Hz,
CH3CH2CH2CH2), 2.55 (t, 2H, J¼7.5 Hz, CH2CuC), 2.99
(t, 2H, J¼7.5 Hz, CH2Ar), 7.12 (td, 1H, J¼7.5 Hz, 1.6,
5-H), 7.17 (td, 1H, J¼7.5, 1.5 Hz, 4-H), 7.24 (bdd, 1H,
J¼7.5, 1.5 Hz, 6-H), 7.36 (dd, 1H, J¼7.5 Hz, 1.6, 3-H). 13C
NMR: 11.28 (d, 3£(CH3)2CH), 13.58 (q, CH3CH2CH2CH2),
18.60 (q, 3£(CH3)2CH), 19.19 (t, CH3CH2CH2CH2),
20.77 (t, CH2CuC), 22.01 (t, CH3CH2CH2CH2), 30.88 (t,
CH3CH2CH2CH2), 34.26 (t, CH2Ar), 78.83 (s, ArCuC),
80.61 (s, TIPSCuC), 94.38 (s, ArCuC), 108.41 (s,
TIPSCuC), 123.35 (s, C-2), 126.10 (d, C-4), 127.47 (d,
5.2.1. Triisopropyl(5-phenyl-1,2-dihydro-3-acenaphthyl-
enyl)silane 19b. IR: 3082 w (sh), 3063 m, 3035 m, 2945 vs,
2927 vs, 2891 s, 2866 vs, 2170 w, 1714 m, 1608 m, 1601 m,
1576 m, 1561 m, 1502 m, 1463 s, 1456 m, 1446 s, 1425 m,
1417 m, 1389 m, 1383 m, 1367 m, 1342 m, 1327 m, 1286 m,
1254 m, 1178 w, 1164 w, 1092 m, 1073 m, 1032 m, 1016 s,
1008 s, 883 vs, 846 m, 703 vs, 679 s, 663 m, 622 m, 595 m,
526 s, 420 w. 1H NMR (500 MHz): 1.14 (d, 18H, J¼7.5 Hz,
3£(CH3)2CH), 1.59 (septet, 3H, J¼7.5 Hz, 3£(CH3)2CH),
3.42–3.44 (m, 2H, 2-H), 3.49–3.51 (m, 2H, 1-H), 7.31 (bd,
1H, J¼6.8 Hz, 6-H), 7.38–7.42 (m, 1H, 4-H (Ph)), 7.43 (dd,
1H, J¼8.2, 6.8 Hz, 7-H), 7.47–7.51 (m, 2H, 3, 5-H (Ph)),
7.51 (s, 1H, 4-H), 7.55 (dd, 1H, J¼8.2, 1.7 Hz, 8-H), 7.69
(dd, 2H, J¼8.2, 0.8 Hz, 6-H (Ph)). 13C NMR: 11.9
(d, 3£(CH3)2CH), 18.8 (q, 3£(CH3)2CH), 30.4 (t, C-1),
32.5 (t, C-2), 119.2 (d, C-6), 120.6 (d, C-7), 125.8 (s, C-8a),
126.8 (d, C-4 (Ph)), 128.2 (d, C-8), 128.3 (d, C-2, 6 (Ph)),
129.9 (d, C-3, 5 (Ph)), 130.1 (s, C-8b), 134.3 (s, C-5a), 135.3
(d, C-4), 139.1 (s, C-5), 140.9 (s, C-1 (Ph)), 146.1 (s, C-2a),
153.7 (s, C-3). EI MS: 386 (Mþz, 22), 343 (17), 301 (20),
273 (8), 259 (15), 243 (20), 202 (100), 173 (7), 144 (6), 101

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9016
(8), 69 (12), 43 (13). HR EI MS: calculated for C27H34Si
386.2430; found 386.2435.
3£(CH3)2CH), 29.8 (t, C-1), 32.8 (t, C-2), 55.5 (q, CH3O),
102.6 (d, C-8), 111.0 (d, C-6), 122.4 (s, C-5), 129.1 (s, C-3),
134.0 (s, C-8b), 136.2 (s, C-8a), 142.6 (d, C-4), 148.6 (s,
C-5a), 155.4 (s, C-2a), 160.1 (s, C-7). EI MS: 412 (Mþz, 85),
397 (10), 369 (86), 354 (7), 327 (75), 313 (12), 299 (18), 285
(47), 253 (28), 239 (17), 225 (10), 209 (6), 157 (12), 149
(43), 142 (50), 73 (100), 59 (26), 41 (22). HR EI MS:
calculated for C25H40OSi2 412.2618; found 412.2608.
5.2.2. [(1E)-1-(2,3-Dihydro-1H-inden-1-ylidene)-3-phenyl-
2-propynyl](triisopropyl)silane 20. IR: 2946 vs, 2926 s,
2891 m, 2866 vs, 2175 w, 1596 w, 1547 w, 1488 m, 1464 m,
1442 w, 1383 w, 1367 w, 1327 w, 1279 vw, 1175 vw, 1094
w, 1070 w, 1036 w (sh), 1020 m, 997 w, 942 vw, 913 w,(sh),
1
883 m, 690 m, 645 m, 613 w, 590 w, 492 w. H NMR
(500 MHz): 1.21 (d, 18H, J¼7.4 Hz, 3£(CH3)2CH), 1.55
(septet, 3H, J¼7.4 Hz, 3£(CH3)2CH), 2.94–3.02 (m, 4H, 2,
3-H), 7.25–7.36 and 7.43–7.46 (m, 9H, 4,5,6,7-H (indene)
and 2,3,4,5,6-H (Ph)). 13C NMR: 12.9 (d, 3£ (CH3)2CH),
19.0 (q, 3£(CH3)2CH), 30.4 (t, C-2), 34.1 (t, C-3), 94.0 (s,
PhCuC), 97.5 (s, PhCuC), 109.8 (s, CvC–Si), 125.0 (d,
C-7), 125.2 (s, C-1 (Ph)), 126.0 (d, C-6), 126.2 (d, C-5),
127.3 (d, C-4), 128.4 (d, C-3,5 (Ph)), 129.0 (d, C-4 (Ph)),
130.8 (d, C-2,6 (Ph)), 142.4 (s, C-3a), 148.1 (s, C-7a), 162.4
(s, C-1). EI MS: 386 (Mþz, 70), 343 (100), 301 (20), 273 (9),
259 (18), 229 (29), 199 (15), 185 (15), 171 (15), 157 (16),
145 (24), 129 (14), 115 (18), 87 (10), 73 (21), 59 (51), 43
(15). HR EI MS: calculated for C27H34Si 386.2430; found
386.2419.
5.3. Reaction of 15 with (trimethylsilyl)acetylene in
diisopropylamine to give 23–25
Method B: 15 (101 mg, 0.220 mmol), Pd(PPh3)4 (12 mg,
0.010 mmol, 5 mol%), (trimethylsilyl)acetylene (45 ml,
0.318 mmol, 1.4 equiv.), diisopropylamine (2 ml), 808C,
1.5 h. Flash chromatography on silica gel (petroleum ether–
ether 100:0 to 99:1) afforded the most lipophilic 15 (22 mg,
22% recovery), then 24 (9 mg, 10%), 25 (8 mg, 9%), and the
most polar 23 (52 mg, 55%).
5.3.1. Triisopropyl[8-methoxy-6-(trimethylsilyl)-1H,3H-
benzo[de]isochromen-4-yl]silane 23. IR: 3009 m, 2868 s,
2840 m, 1629 w, 1602 m, 1561 w, 1505 w, 1441 m, 1316 m,
1262 m, 1251 s, 1192 w, 1071 s, 1046 s, 1027 m, 882 s, 854
1
5.2.3. 2-[4-(Triisopropylsilyl)-3-butynyl]benzonitrile 21.
A Schlenk flask was charged with iodide 11 (60 mg,
0.145 mmol) and Pd(PPh3)4 (8 mg, 0.007 mmol, 5 mol%).
Diisopropylamine (1.5 ml) was added and the mixture was
briefly heated under stirring at 40–508C. Trimethylsilyl
cyanide (29 ml, 0.232 mmol, 1.6 equiv.) was added and the
reaction mixture was stirred at 808C for 2.5 h. The
precipitate was filtered off and the filtrate was evaporated
to dryness. Flash chromatography on silica gel (petroleum
ether–ether 100:0 to 96:4) afforded 11 (28 mg, 46%
recovery) and the more polar cyanide 21 (19 mg, 43%) as
an oil. IR: 3074 w, 3060 w, 3027 w, 2892 s, 2866 vs, 2226 s,
2172 s, 1601 m, 1575 w, 1487 m, 1463 s, 1452 s, 1435 s,
1383 m, 1367 w, 1338 w, 1330 w, 1120 m, 1097 m, 1072 m,
1028 m, 996 s, 953 w, 884 s, 861 w, 696 s, 679 s, 661 s, 602
vs, 637 m. H NMR (500 MHz): 0.28 (s, 9H, (CH3)3Si),
1.16 (d, 18H, J¼7.4 Hz, 3£(CH3)2CH), 1.43 (m, 3H, 3£
(CH3)2CH), 3.84 (s, 3H, CH3O), 4.70 (t, 2H, J¼0.8 Hz,
1-H), 4.87 (d, 2H, J¼0.7 Hz, 3-H), 6.51 (dt, 1H, J¼2.0,
0.8 Hz, 9-H), 6.77 (t, 1H, J¼0.8 Hz, 5-H), 6.92 (dt, 1H,
J¼2.0, 0.7 Hz, 7-H). 13C NMR: 20.1 (q, (CH3)3Si), 12.9 (d,
3£(CH3)2CH), 19.1 (q, 3£(CH3)2CH), 56.0 (q, CH3O), 66.8
(t, C-1), 67.0 (t, C-3), 102.4 (d, C-9), 103.3 (s, C-6), 105.9
(d, C-7), 124.1 (s, C-9b), 137.3 (s, C-4), 140.4 (s, C-9a),
143.4 (s, C-6a), 144.7 (d, C-5), 147.5 (s, C-3a), 160.8 (s,
C-8). EI MS: 428 (Mþz, 24), 413 (5), 385 (50), 355 (10), 343
(6), 269 (18), 256 (5), 241 (17), 227 (5), 157 (7), 133 (10),
115 (17), 107 (15), 87 (18), 73 (100), 59 (62), 45 (18). HR EI
MS: calculated for C25H40O2Si2 428.2567; found 428.2543.
1
m, 557 m, 480 m. H NMR (200 MHz): 1.00 (brs, 18H,
5.3.2. Triisopropyl[8-methoxy-5-(trimethylsilyl)-1H,3H-
benzo[de]isochromen-4-yl]silane 24. IR: 3031 w, 3010 m,
2868 s, 1558 w, 1465 s, 1384 m, 1368 m, 1308 m, 1251 s,
1178 m, 1075 s, 1036 s, 998 m, 883 s, 844 vs, 691 w, 661 m,
640 m, 609 w. 1H NMR (500 MHz): 0.45 (s, 9H, (CH3)3Si),
1.13 (d, 18H, J¼7.5 Hz, 3£(CH3)2CH), 1.49 (m, 3H, 3£
(CH3)2CH), 3.91 (s, 3H, CH3O), 5.01 (dd, 2H, J¼1.1,
0.7 Hz, 1-H), 5.09 (s, 2H, 3-H), 6.83 (dt, 1H, J¼2.5, 1.1 Hz,
9-H), 7.27 (dt, 1H, J¼2.6, 0.7 Hz, 7-H), 7.77 (s, 1H, 6-H).
13C NMR: 0.1 (q, (CH3)3Si), 12.7 (d, 3£(CH3)2CH), 19.1 (q,
3£(CH3)2CH), 55.2 (q, CH3O), 69.8 (t, C-1), 70.8 (t, C-3),
105.6 (d, C-7), 111.8 (d, C-9), 122.3 (s, C-9b), 123.4 (s,
C-6a), 132.8 (s, C-9a), 135.5 (s, C-4), 138.4 (s, C-5), 140.7
(d, C-6), 141.7 (s, C-3a), 157.1 (s, C-8). EI MS: 428 (Mþz,
32), 385 (93), 343 (13), 313 (7), 205 (12), 165 (8), 149 (50),
135 (11), 111 (13), 97 (21), 85 (27), 73 (100), 57 (89), 43
(93). HR EI MS: calculated for C25H40O2Si2 428.2567;
found 428.2549.
3£(CH3)2CH), 1.01 (s, 3H, 3£(CH3)2CH), 2.68 (t, 2H,
J¼7.0 Hz, CuCCH2), 3.07 (t, 2H, J¼7.0 Hz, CH2Ar),
7.30–7.68 (m, 4H, arom.). EI MS: 268 ((M2C3H7)þ, 100),
240 (6), 226 (8), 198 (8), 182 (7), 59 (7). HR EI MS:
calculated for C17H22NSi (M2C3H7) 268.1522; found
268.1520.
5.2.4. Triisopropyl[7-methoxy-5-(trimethylsilyl)-1,2-
dihydro-3-acenaphthylenyl]silane 22. Method B: 12
(85 mg, 0.190 mmol), Pd(PPh3)4 (11 mg, 0.00952 mmol,
5 mol%), (trimethylsilyl)acetylene (30 ml, 0.230 mmol,
1.2 equiv.), diisopropylamine (3 ml), 808C, 16 h. Flash
chromatography on silica gel (petroleum ether–ether
99:1) afforded 22 (60 mg, 72%) as an oil. IR: 3052 w,
3006 w, 2891 m, 2866 vs, 1616 s, 1588 w, 1556 w, 1464 s,
1445 w, 1389 w, 1383 w, 1367 w, 1333 w, 1300 w, 1251 s,
1073 w, 1029 m, 995 w, 883 s, 841 vs, 677 m, 662 m, 645 m.
1H NMR (500 MHz): 0.43 (s, 9H, (CH3)3Si), 1.11 (d, 18H,
J¼7.5 Hz, 3£(CH3)2CH), 1.53 (septet, 3H, J¼7.5 Hz,
3£(CH3)2CH), 3.29–3.33 (m, 2H, 1-H), 3.41–3.43 (m,
2H, 2-H), 3.92 (s, 3H, CH3O), 6.96 (dt, 1H, J¼2.1, 1.5 Hz,
8-H), 7.11 (dt, 1H, J¼2.1, 0.8 Hz, 6-H), 7.70 (s, 1H, 4-H).
13C NMR: 0.0 (q, (CH3)3Si), 11.9 (d, 3£(CH3)2CH), 18.8 (q,
5.3.3. Triisopropyl[(1Z)-1-(7-methoxy-1H-isochromen-
4(3H)-ylidene)-3-(trimethylsilyl)-2-propynyl]silane 25.
IR: 3031 w, 3010 m, 2867 vs, 2107 w, 1608 s, 1573 w,
1492 s, 1466 s, 1437 w (sh), 1384 w, 1368 w, 1324 m, 1269
s, 1250 s, 1177 w, 1162 w, 1034 m, 998 m, 883 s, 845 s, 696

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9017
w, 681 w, 645 w. 1H NMR (500 MHz): 0.19 (s, 9H,
(CH3)3Si), 1.15 (d, 18H, J¼7.4 Hz, 3£(CH3)2CH), 1.44 (m,
3H, 3£(CH3)2CH), 3.82 (s, 3H, CH3O), 4.38 (s, 1H, 3-H),
4.81 (dd, 1H, J¼1.0, 0.8 Hz, 1-H), 6.53 (dt, 1H, J¼2.7 Hz,
1.0, 8-H), 6.75 (ddt, 1H, J¼9.0, 2.7, 0.8 Hz, 6-H), 8.96 (d,
1H, J¼9.0 Hz, 5-H). 13C NMR: 20.3 (q, (CH3)3Si), 13.3 (d,
3£(CH3)2CH), 18.9 (q, 3£(CH3)2CH), 55.3 (q, CH3O), 68.9
(t, C-1), 70.3 (t, C-3), 103.8 (s, SiCuC), 108.3 (d, C-8),
109.3 (s, SiCuC), 111.6 (d, C-6), 112.9 (s, SiCvC), 127.0
(s, C-4a), 130.2 (d, C-5), 137.7 (s, C-8a), 150.5 (s, SiCvC),
159.6 (s, C-7). EI MS: 428 (Mþz, 51), 385 (26), 355 (66),
257 (6), 241 (7), 225 (7), 183 (5), 165 (5), 142 (10), 133
(18), 115 (11), 91 (22), 73 (100), 59 (75), 45 (19). HR EI
MS: calculated for C25H40O2Si2 428.2567; found 428.2565.
55.3 (q, CH3O), 69.0 (t, C-1), 70.2 (t, C-3), 105.5 (s,
(CH3)3SiCuC), 108.0 (s, (CH3)3SiCuC), 108.8 (d, C-1),
111.9 (d, C-6), 115.1 (s, (CH3)3SiCvC), 126.0 (s, C-4a),
129.8 (d, C-5), 137.8 (s, C-8a), 148.7 (s, C-4), 159.6 (s,
C-7). EI MS: 344 (Mþz, 26), 329 (5), 271 (9), 241 (5), 147
(71), 134 (24), 73 (100), 59 (7), 45 (14). HR EI MS:
calculated for C19H28O2Si2 344.1628; found 344.1621.
5.4.3. [(3E)-3-(7-Methoxy-1H-isochromen-4(3H)-yl-
idene)-1-butynyl](trimethyl)silane 28. Method B: 17
(24 mg, 0.076 mmol), Pd(PPh3)4 (4 mg, 0.003 mmol,
5 mol%), (trimethylsilyl)acetylene (30 ml, 0.212 mmol,
2.8 equiv.), diisopropylamine (2 ml), 808C, 10 h. Flash
chromatography on silica gel (petroleum ether–ether
100:0 to 99:1) afforded 28 (8 mg, 37%) as an oil. IR:
2839 w, 2131 w, 1610 m, 1588 w, 1570 w, 1495 m, 1436 w,
1409 w, 1307 m, 1249 s, 1192 w, 1164 w, 1116 m, 1061 m,
5.4. Reaction of 15 with (trimethylsilyl)acetylene in
piperidine to get 24–26
1
1033 w, 933 w, 888 m, 866 m, 845 vs, 698 w. H NMR
Method B: 15 (21 mg, 0.046 mmol), Pd(PPh3)4 (2.7 mg,
0.002 mmol, 5 mol%), (trimethylsilyl)acetylene (17 ml,
0.120 mmol, 1.6 equiv.), piperidine (2 ml), 808C, 1.5 h.
Flash chromatography on silica gel (petroleum ether–ether
100:0 to 99:1) afforded the most lipophilic 26 (6 mg, 30%),
then 24 (1 mg, 5%), and the most polar 25 (11 mg, 56%) as
oils. Compounds 24 and 25: for spectral data, see above.
(200 MHz): 0.23 (s, 9H, (CH3)3SiCuC), 1.93 (s, 3H,
CH3CvC), 3.82 (s, 3H, CH3O), 4.52 (d, 2H, J¼1.2 Hz,
3-H), 4.59 (s, 2H, 1-H), 6.60 (d, 1H, J¼2.8 Hz, 8-H), 6.78
(dd, 1H, J¼8.9, 2.8 Hz, 6-H), 8.68 (d, 1H, J¼8.9 Hz, 5-H).
EI MS: 286 (Mþz, 70), 271 (15), 243 (8), 213 (9), 185 (11),
173 (6), 159 (8), 134 (16), 122 (25), 97 (11), 83 (39), 73
(1000, 57 (15), 43 (15). HR EI MS: calculated for
C17H22O2Si 286.1389; found 286.1394.
5.4.1. {[4-Methoxy-2-({[3-(triisopropylsilyl)-2-propynyl]-
oxy}methyl)phenyl]ethynyl}(trimethyl)silane 26. IR:
3080 w, 3061 w, 3010 m, 2867 vs, 2172 w (sh), 2150 s,
1606 s, 1568 m, 1494 s, 1466 s, 1438 s, 1408 w, 1384 m,
1367 m, 1351 m, 1300 s, 1280 s, 1251 vs, 1192 w, 1164 s,
1120 s, 1079 s, 1029 s, 999 s, 947 w, 883 s, 862 vs, 845 vs,
695 m, 680 s, 663 m, 636 m. 1H NMR (500 MHz): 0.24 (s,
9H, (CH3)3Si), 1.07–1.11 (m, 21H, 3£(CH3)2CH), 3.81 (s,
3H, CH3O), 4.31 (s, 2H, CH2CuC), 4.75 (t, 2H, J¼0.7 Hz,
CH2Ar), 6.74 (ddt, 1H, J¼8.5, 2.7, 0.6 Hz, 5-H), 7.02 (dt,
1H, J¼2.7, 0.8 Hz, 3-H), 7.37 (d, 1H, J¼8.5 Hz, 6-H). 13C
NMR: 0.1 (q, (CH3)3Si), 11.1 (d, 3£(CH3)2CH), 18.6 (q,
3£(CH3)2CH), 55.3 (q, CH3O), 58.9 (t, CH2CuC), 69.6 (t,
CH2Ar), 87.8 (s, TIPSCuC), 97.5 (s, TMSCuC), 102.6 (s,
TIPSCuC), 103.3 (s, TMSCuC), 112.3 (d, C-3), 113.2 (d,
C-5), 113.5 (s, C-1), 133.8 (d, C-6), 142.1 (s, C-2), 160.0 (s,
C-4). EI MS: 428 (Mþz, 7), 385 (3), 355 (8), 243 (15), 217
(6), 178 (13), 161 (8), 149 (78), 128 (23), 105 (11), 97 (21),
83 (30), 73 (73), 57 (95), 43 (100). HR EI MS: calculated for
C25H40O2Si2 428.2567; found 428.2562.
5.4.4. [(3E)-3-(1H-Isochromen-4(3H)-ylidene)-1-buty-
nyl](trimethyl)silane 29. Method B: 14 (100 mg,
0.350 mmol), Pd(PPh3)4 (20 mg, 0.0173 mmol, 5 mol%),
(trimethylsilyl)acetylene (100 ml, 0.708 mmol, 2.0 equiv.),
piperidine (2 ml), 808C, 4 h. Flash chromatography on silica
gel (petroleum ether–acetone 98:2) afforded 29 (42 mg,
47%) as an oil. IR: 3066 w, 3029 m, 3012 m, 2900 m, 2134
w, 1604 w, 1484 w, 1453 m, 1408 m, 1252 vs, 1163 m, 846
vs, 699 w, 637 w, 429 w. 1H NMR (200 MHz): 0.22 (s, 9H,
(CH3)3Si), 1.95 (s, 3H, CH3), 4.54 (d, 2H, J¼0.9 Hz, 1-H),
4.61 (s, 2H, 3-H), 7.05–7.10 (m, 1H, H-arom.), 7.21–7.25
(m, 2H, H-arom.), 8.66–8.71 (m, 1H, H-arom.). EI MS: 256
(Mþz, 20), 241 (8), 187 (10), 167 (8), 152 (5), 147 (10), 135
(10), 125 (22), 118 (8), 105 (20), 97 (19), 90 (9), 83 (16), 73
(100), 67 (5), 59 (13), 43 (23). HR EI MS: calculated for
C16H20OSi 256.1283; found 256.1274.
Acknowledgements
5.4.2. [(1Z)-1-(7-Methoxy-1H-isochromen-4(3H)-yl-
idene)-3-(trimethylsilyl)-2-propynyl](trimethyl)silane
27. Method B: 16 (94 mg, 0.264 mmol), Pd(PPh3)4 (15 mg,
0.013 mmol, 5 mol%), (trimethylsilyl)acetylene (50 ml,
0.354 mmol, 1.3 equiv.), diisopropylamine (2 ml), 808C,
1.5 h. Flash chromatography on silica gel (petroleum ether–
ether 100:0 to 98:2) afforded 27 (84 mg, 97%) as an oil. IR:
3088 vw, 2900 w, 2840 w, 2106 w, 1608 s, 1574 m, 1493 s,
1466 m, 1456 m, 1444 w, 1435 w, 1408 w, 1296 m, 1272 s,
1252 s, 1236 s, 1193 w, 1164 m, 1117 m, 1065 s, 1033 s, 847
vs, 696 w, 636 w, 543 w. 1H NMR (500 MHz): 0.22 (s, 9H,
(CH3)3SiCuC), 0.30 (s, 9H, (CH3)3SiCvC), 3.82 (s, 3H,
CH3O), 4.52 (s, 2H, 3-H), 4.74 (dd, 2H, J¼1.0, 0.6 Hz,
1-H), 6.54 (dt, 1H, J¼2.7, 1.0 Hz, 8-H), 6.76 (ddt, 1H,
J¼8.9, 2.7, 0.6 Hz, 6-H), 9.01 (d, 1H, J¼8.9 Hz, 5-H). 13C
NMR: 20.1 (q, (CH3)3SiCuC), 0.5 (q, (CH3)3SiCvC),
The financial support by the Grant Agency of the
Czech Republic (Reg. No. 203/99/1448) is gratefully
´
acknowledged. We are very indebted to Dr J. Zavada of
this Institute for valuable and stimulating discussions.
References
1. For reviews comprising domino (cascade) reactions catalysed
by transition metals see, e.g.: (a) Tietze, L. F. Chem. Rev.
1996, 96, 115. (b) Malacria, M. Chem. Rev. 1996, 96, 289.
(c) Ikeda, S.-I. Acc. Chem. Res. 2000, 33, 511 and references
cited therein.
2. For reviews covering Pd-catalysed domino reactions, see:
(a) Oppolzer, W. Comprehensive Organometallic Chemistry

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F. Teply et al. / Tetrahedron 58 (2002) 9007–9018
9018
II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.;
for Organic Synthesis; Beller, M., Bolm, C., Eds.; Wiley-
VCH: Weinheim, 1998; Vol. 1, p 158 Chapter 2.10.
(g) Sonogashira, K. Metal-catalyzed Cross-coupling
Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH:
Weinheim, 1998; Vol. 5, p 203.
Pergamon: Oxford, 1995; Vol. 12, p 905 Chapter 8.3.
(b) Grigg, R.; Sridharan, V. Comprehensive Organometallic
Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson, G.,
Eds.; Pergamon: Oxford, 1995; Vol. 12, p 299, Chapter 3.6.
´
(c) Negishi, E.-I.; Coperet, C.; Ma, S.; Liou, S.-Y.; Liu, F.
6. For examples of Sonogashira reaction without CuI as a co-
catalyst, see: (a) Chen, Q.-Y.; Yang, Z.-Y. Tetrahedron Lett.
1986, 27, 1171. (b) Alami, M.; Ferri, F.; Linstrumelle, G.
Chem. Rev. 1996, 96, 365. (d) Ojima, I.; Tzamarioudaki, M.;
Li, Z.; Donovan, R. J. Chem. Rev. 1996, 96, 635. (e) Grigg, R.;
Sridharan, V. Pure Appl. Chem. 1998, 70, 1047. (f) Grigg, R.;
Sridharan, V. J. Organomet. Chem. 1999, 576, 65. (g) Grigg,
R.; Sridharan, V. IUPAC Monograph, Davies, S. G.,
Murahashi, S.-I., Eds.; Blackwell: New York, 1999; Vol.
576, p 87. (h) de Meijere, A.; Brase, S. J. Organomet. Chem.
1999, 576, 88. (i) Larock, R. C. Pure Appl. Chem. 1999, 71,
1435.
¨
Tetrahedron Lett. 1993, 34, 6403. (c) Bohm, V. P. W.;
Herrmann, W. A. Eur. J. Org. Chem. 2000, 3679. See also
Ref. 3.
7. For recent discussion on the general mechanism of Pd-cata-
lysed Heck and cross-coupling reactions, see: Amatore, C.;
Jutand, A. Acc. Chem. Res. 2000, 33, 314. We are aware that
pentacoordinated anionic Pd(0) and Pd(II) intermediates may
be involved instead of the simplified structures outlined in
Scheme 4.
ˇ
3. (a) Stara, I. G.; Stary, I.; Kollarovic, A.; Teply, F.; Saman, D.;
´
´
´
Fiedler, P. Tetrahedron 1998, 54, 11209. (b) Stara, I. G.; Stary,
´
´
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´
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I.; Kollarovic, A.; Teply, F.; Saman, D.; Fiedler, P. Collect.
´
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´
8. For a discussion on the mechanism of palladium-catalysed
arylation (formal Friedel–Crafts vinylation), see: (a) Catellani,
M.; Chiusoli, G. P.; Castagnoli, C. J. Organomet. Chem. 1991,
407, C30. (b) Catellani, M.; Chiusoli, G. P. J. Organomet.
Chem. 1992, 425, 151. (c) Canty, A. J. Acc. Chem. Res. 1992,
25, 83. (d) Rice, J. E.; Cai, Z.-W. J. Org. Chem. 1993, 58,
1415. (e) Brown, D.; Grigg, R.; Sridharan, V.; Tambyrajah, V.
Tetrahedron Lett. 1995, 36, 8137. (f) Grigg, R.; Loganathan,
V.; Sridharan, V. Tetrahedron Lett. 1996, 37, 3399.
Czech. Chem. Commun. 1999, 64, 649.
ˇ
4. (a) Stara, I. G.; Stary, I.; Kollarovic, A.; Teply, F.; Saman, D.;
´
´
´
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´
´
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Tichy, M. Chimia 1997, 51, 378. (b) Stara, I. G.; Stary, I.;
´
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Kollarovic, A.; Teply, F.; Saman, D.; Tichy, M. J. Org. Chem.
´
´ ˇ
1998, 63, 4046. (c) Stara, I. G.; Stary, I.; Kollarovic, A.; Teply,
ˇ
´
´
´
´
´
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F.; Vyskocil, S.; Saman, D. Tetrahedron Lett. 1999, 40, 1993.
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(d) Stara, I. G.; Kollarovic, A.; Teply, F.; Stary, I.; Saman, D.;
´
´
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´
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Fiedler, P. Collect. Czech. Chem. Commun. 2000, 65, 577.
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(e) Teply, F.; Stara, I. G.; Stary, I.; Kollarovic, A.; Saman, D.;
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(g) Gonzalez, J. J.; Garcıa, N.; Gomez-Lor, B.; Echavarren,
A. M. J. Org. Chem. 1997, 62, 1286. (h) Catellani, M.;
Frigmeni, F.; Rangoni, A. Angew. Chem., Int. Ed. Engl. 1997,
36, 119. (i) Larock, R. C.; Tian, Q. J. Org. Chem. 1998, 63,
2002. (j) Coudanne, I.; Balme, G. Synlett 1998, 998. (k) Grigg,
R.; Savic, V.; Tambyrajah, V. Tetrahedron Lett. 2000, 40,
3003.
´ˇ
Rulısek, L.; Fiedler, P. J. Am. Chem. Soc. 2002, 124, 9175.
5. For reviews on Sonogashira coupling under Pd(0)/Cu(I)
catalysis, see: (a) Brandsma, L. Preparative Acetylenic
Chemistry; 2nd ed., Elsevier: Amsterdam, 1988.
(b) Sonogashira, K. Comprehensive Organic Synthesis;
Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon:
Oxford, 1991; Vol. 3, p 521 Chapter 2.4. (c) Winterfeldt, E.
Modern Synthetic Methods; Scheffold, R., Ed.; VCH:
Weinheim, 1992; p 103. (d) Rossi, R.; Carpita, A.; Bellina,
F. Org. Prep. Proc. Int. 1995, 27, 127. (e) Farina, V.
Comprehensive Organometallic Chemistry II; Abel, E. W.,
Stone, F. G. A., Wilkinson, G., Eds.; Pergamon: Oxford, 1995;
Vol. 12, p 162 Chapter 3.4. (f) Geisler, H. Transition Metals
9. Alternatively, an insertion into the aryl C–H bond in G
(Scheme 4) to form a palladium(IV) intermediate followed by
proton abstraction by a base to give the palladacycle I may
take place as discussed in Ref. 8a–c,e,f,h–k.
´
10. (a) L’abbe, G.; Leurs, S.; Sannen, I.; Dehaen, W. Tetrahedron
1993, 49, 4439. (b) Sperandio, D.; Hansen, H.-J. Helv. Chim.
Acta 1995, 78, 765.