Palladium-Catalyzed Cross-Coupling Syntheses of Benzotriazolyl Enynes and a General Route to Enynyl Ketones and Alkynyl Ketones

Article abstract of DOI:10.1021/jo971234c

A new general route to conjugated enynyl ketones was developed based on a two-step procedure. First, palladium-catalyzed cross-coupling reactions of 1-(benzotriazol-1-yl)propargyl ethyl ether (3) and vinyl triflates or vinyl bromides afforded the key intermediates [1-(benzotriazol-1-yl)-1-enynyl]-methyl ethyl ethers 5a-d in good yields. Then reactions of compounds 5 with primary halides gave intermediates 8, which were hydrolyzed by dilute acid to enynyl ketones 9a-g. Similar palladium-catalyzed coupling reactions of 3 with various aryl iodides followed by an analogous sequence afforded aryl-substituted propargyl ethers 12a-d and thence alkynyl ketones 13a,b.

Full text of DOI:10.1021/jo971234c

J . Org. Chem. 1997, 62, 8201-8204
8201
P a lla d iu m -Ca ta lyzed Cr oss-Cou p lin g Syn th eses of Ben zotr ia zolyl
En yn es a n d a Gen er a l Rou te to En yn yl Keton es a n d Alk yn yl
Keton es
Alan R. Katritzky,* J iangchao Yao, and Ming Qi
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida,
Gainesville, Florida 32611-7200
Received J uly 8, 1997X
A new general route to conjugated enynyl ketones was developed based on a two-step procedure.
First, palladium-catalyzed cross-coupling reactions of 1-(benzotriazol-1-yl)propargyl ethyl ether (3)
and vinyl triflates or vinyl bromides afforded the key intermediates [1-(benzotriazol-1-yl)-1-enynyl]-
methyl ethyl ethers 5a -d in good yields. Then reactions of compounds 5 with primary halides
gave intermediates 8, which were hydrolyzed by dilute acid to enynyl ketones 9a -g. Similar
palladium-catalyzed coupling reactions of 3 with various aryl iodides followed by an analogous
sequence afforded aryl-substituted propargyl ethers 12a -d and thence alkynyl ketones 13a ,b.
In tr od u ction
rivatives are useful acyl anion synthon equivalents for
Enynyl ketones are important intermediates in the
syntheses of various natural products and their
analogues.1-4 Common routes to enynyl ketones are
based on reactions of enynyl organometallic reagents
(e.g., those of magnesium,5,6 lithium,3,7 copper,8 and
silicon9) with carboxylic acid chlorides, esters, or anhy-
drides. However, such reactions of enynyllithium or
magnesium reagents with carboxylic acid derivatives are
not always satisfactory.5 Reactions between enynylsi-
lanes and acid chlorides require 1 equiv of titanium
tetrachloride as Lewis acid, and only two examples have
been reported.9 The cuprous-catalyzed reaction of acid
chlorides and enynes can afford enynyl ketones in good
yields in the presence of triethylamine as the base,10 but
this method is not applicable to primary acid chlorides,
such as acetyl, propanoyl, and butanoyl chlorides, which
react readily with triethylamine.11 Other routes to
enynyl ketones include oxidations of the corresponding
alcohols by CrO3,5 PDC,4 or Swern reagents12 in moderate
yields: the alcohols were prepared through the pal-
ladium-catalyzed coupling reactions between vinyl bro-
mides and 3-hydroxyalkynylstannanes. However, all of
the aforementioned preparations of enynyl ketones show
some problems in the availability of starting materials
and/or lack of generality. Recent work in this group has
demonstrated that 1-benzotriazolyl-1-ethoxymethyl de-
the syntheses of various classes of ketones. For example,
1-(benzotriazol-1-yl)allyl ethyl ether (1)13 and 1-(benzo-
triazol-1-yl)propargyl ethyl ether (3)14 are useful equiva-
lents for propenoyl anion 2 in the synthesis of vinyl
ketones and propynoyl anion 4 in the preparation of
alkynyl ketones, respectively. Now we report that this
methodology can be extended to various 1-(benzotriazol-
1-yl)-1-enynylmethyl ethyl ethers of general structure 5,
which provide general and versatile (enynyl)acyl anion
synthon equivalents 6 for the synthesis of diverse enynyl
ketones.
Resu lts a n d Discu ssion
P a lla d iu m -Ca t a lyzed Cou p lin g R ea ct ion s b e-
tw een Vin yl Tr ifla tes or Br om id es a n d 1-(Ben zo-
tr ia zol-1-yl)p r op a r gyl Eth yl Eth er (3) for th e Syn -
th esis of En yn yl Ben zotr ia zoles 5a -d a n d En yn yl
Keton es 9a -g. Palladium-copper-catalyzed reactions
of 1-alkynes and vinyl halides or vinyl triflates are
commonly used to introduce enynyl groups in organic
synthesis.15,16 We have now coupled 1-(benzotriazol-1-
yl)propargyl ethyl ether (3) with vinyl triflates and vinyl
bromides for the synthesis of 1-(benzotriazol-1-yl)enynyl
ethyl ethers 5. Under the general palladium-copper-
catalyzed conditions,17,18 compound 3 reacted with 1-cy-
X Abstract published in Advance ACS Abstracts, October 15, 1997.
(1) Hirama, M.; Fujiwara, K.; Shigematu, K.; Fukazawa, Y. J . Am.
Chem. Soc. 1989, 111, 4120.
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1988, 110, 5904.
(3) Suzuki, K.; Tomooka, K.; Katayama, E.; Matsumoto, T.; Tsuchi-
hashi, G.-i. J . Am. Chem. Soc. 1986, 108, 5221.
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Chem. Soc. 1946, 39.
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Chem. Soc. 1949, 1827.
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Chem. 1988, 53, 652.
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(10) Shergina, S. I.; Sokolov, I. E.; Zanina, A. S. Mendeleev Commun.
1994, 207.
(11) Furber, M. In Comprehensive Organic Functional Group Trans-
formations; Katritzky, A. R., Meth-Cohn, O., Rees, C. W., Eds.; Elsevier
Science Inc.: Oxford, 1995; Vol. 1, p 997.
(13) Katritzky, A. R.; Zhang, G.; J iang, J . J . Org. Chem. 1995, 60,
7589.
(14) Katritzky, A. R.; Lang, H. J . Org. Chem. 1995, 60, 7612.
(15) Rossi, R.; Carpita, A.; Bellina, F. Org. Prep. Proced. Int. 1995,
27, 127.
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1522.
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1975, 4467.
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31, 4329.
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Y.; Yamanaka, H. Synthesis 1992, 746.
S0022-3263(97)01234-6 CCC: $14.00 © 1997 American Chemical Society

8202 J . Org. Chem., Vol. 62, No. 23, 1997
Katritzky et al.
Sch em e 1
Sch em e 3
Sch em e 2
pargyl ethyl ether (3),14 the carbanions of compounds 5
appear to be less stable.
P a lla d iu m -Ca t a lyzed Cou p lin g R ea ct ion s b e-
t w een Ar yl Iod id es a n d 1-(Ben zot r ia zol-1-yl)p r o-
p a r gyl Eth yl Eth er (3) for th e Syn th esis of 1-(Ben -
zotr ia zol-1-yl)-3-a r ylp r op a r gyl Eth yl Eth er s 12a -d
a n d Alk yn yl Keton es 13a ,b. We previously reported
that 3-substituted 1-(benzotriazol-1-yl)propargyl ethyl
ether (3) can be prepared from the corresponding sub-
stituted propargyl aldehyde acetals, as useful synthons
for the synthesis of various alkynyl ketones.14 However,
except for 3-phenylpropargyl aldehyde acetal, no aryl-
substituted propargyl aldehyde acetal is commercially
available. We have now developed a general route to
3-aryl-1-(benzotriazol-1-yl)propargyl ethyl ethers 12a -d
by palladium-copper-catalyzed coupling reactions of
compound 3 with aryl halides. Both electron-rich and
electron-deficient aryl iodides gave good yields (Scheme
3).
Ta ble 1. P r ep a r a tion of En yn yl Keton es
products
R1
R2
R3
X2
yield (%)
9a
9b
9c
9d
9e
9f
-(CH2)4-
n-C6H13
CH3
Br
I
60
42
50
60
50
67
75
C6H5
H
H
H
H
H
H
C6H5
C6H5
C6H5
Me3Si
Me3Si
CH3CH2
n-C4H9
n-C10H21
C6H5CH2
n-C7H15
Br
Br
Br
Cl
Br
9g
clohexenyl triflate (7a ), â-bromostyrene (7b), (2-bromo-
vinyl)trimethylsilane (7c), and 1-cyclopentenyl triflate
(7d ) to afford the desired products 5a -d , respectively,
in good yields (Scheme 1).
As expected based upon previous work on compound
12a ,14
compound 12b, after lithiation by n-BuLi, subse-
quent reaction with 1-bromohexane, and hydrolysis
under acidic conditions, gave alkynyl ketone 13a in 80%
yield (Scheme 3). Similarly, compound 12c, which bears
an electron-donating group (4-methoxy), reacted with
n-BuLi and iodomethane to afford alkynyl ketone 13b
in 70% yield after acid hydrolysis. Unlike the reactions
of 5, reactions of 12 can be run stepwise using n-BuLi as
the base, apparently because their carbanion intermedi-
ates are more stable that those of lithiated 5.
The reactions probably proceed through the commonly
accepted mechanism.11,17 However, as the benzotriazolyl
group present in the substrate is a good coordinator, it
affects the electronic and steric environment of pal-
ladium.
In the presence of lithium hexamethyldiazasilane as
base, compounds 5 reacted with various primary halides
as expected to introduce an alkyl group at the R-position
to the benzotriazolyl group (e.g., 8a , Scheme 2). Hy-
drolysis of 8a under acidic conditions afforded the desired
enynyl ketone 9a in 60% overall yield (two steps from
5a ). Similarly, 9b-g were prepared without the isolation
of the alkylated intermediates (Table 1).
When allyl bromide was used as the electrophile,
â-benzotriazolyl enynyl ketone 10 was isolated in 70%
yield. This is due to the double-bond (from allyl bromide)
migration from â,γ to R,â of the carbonyl group under
acidic conditions and subsequent Michael addition of
benzotriazole to the R,â-unsaturated ketone (Scheme 2).19
The use of lithium hexamethyldiazasilane and the one-
step procedure now described were crucial for the present
reactions. The stepwise procedure (lithiation of 5 with
n-BuLi or s-BuLi followed by addition of the electrophile)
of previous reports13,14 failed for the present reactions.
In comparison with the carbanions from 1-(benzotriazol-
1-yl)allyl ethyl ether (1)13 and 1-(benzotriazol-1-yl)pro-
Con clu sion s
In conclusion, we developed a novel route for the
synthesis of enynyl ketones 9, utilizing palladium-
catalyzed coupling reactions between 1-(benzotriazol-1-
yl)propargyl ethyl ether (3) and vinyl bromides or vinyl
triflates to give new enynyl acyl anion synthons 5 in
moderate to good yields. It is noteworthy that whereas
all previously reported routes to enynyl ketones were
based on the formation of bond a, the present method is
based on the formation of bond b in structure 14.
14
We also explored the palladium-catalyzed coupling
reaction of aryl iodides with compound 3, which provides
(19) Katritzky, A. R.; Rachwal, S.; Hughes, C. V.; Wang, Z. Pol. J .
Chem. 1992, 66, 1633.

New General Route to Conjugated Enynyl Ketones
J . Org. Chem., Vol. 62, No. 23, 1997 8203
8.4 Hz), 8.10 (d, 1H, J ) 8.4 Hz); 13C NMR δ 14.6, 21.4, 64.5,
78.5, 80.8, 88.4, 111.6, 117.9, 120.0, 124.4, 127.8, 129.1, 131.3,
131.8, 139.7, 146.8; MS m/z 291 (M+, 6), 276 (6), 173 (100).
Anal. Calcd for C18H17N3O: C, 74.20; H, 5.88; N, 14.42.
Found: C, 73.86; H, 6.01; N, 14.42.
an alternative route to various aryl-substituted 1-(ben-
zotriazol-1-yl)propargyl ethyl ethers 12.
Exp er im en ta l Section
1-(Ben zot r ia zol-1-yl)-3-(4-m et h oxyp h en yl)p r op a r gyl
eth yl eth er (12c): colorless oil; H NMR δ 1.08 (t, 3H, J )
Gen er a l Com m en ts. Melting points were measured on a
hot-stage microscope and are uncorrected. 1H and 13C NMR
data were collected on a 300 MHz NMR spectrometer (300 and
75 MHz, respectively) using CDCl3 as solvent.
1
6.5 Hz), 3.41-3.51 (m, 1H), 3.65-3.75 (m, 1H), 3.82 (s, 3H),
6.83 (d, 2H, J ) 8.3 Hz), 7.02 (s, 1H), 7.39-7.46 (m, 3H), 7.55
(t, 1H, J ) 7.5 Hz), 8.02 (d, 1H, J ) 8.4 Hz), 8.06 (d, 1H, J )
8.4 Hz); 13C NMR δ 14.5, 55.2, 64.4, 79.0, 80.1, 88.3, 111.5,
112.7, 113.9, 119.9, 124.4, 127.7, 131.2, 133.4, 146.7, 160.4;
MS m/z 307 (M+, 8), 189 (100). Anal. Calcd for C18H17N3O2:
C, 70.34; H, 5.58; N, 13.67. Found: C, 70.08; H, 5.77; N, 13.52.
1-(Ben zotr ia zol-1-yl)-3-(4-n itr op h en yl)p r op a r gyl eth yl
eth er (12d ): yellow plates, mp 90-91 °C; 1H NMR δ 1.22 (t,
3H, J ) 6.9 Hz), 3.43-3.53 (m, 1H), 3.66-3.76 (m, 1H), 7.06
(s, 1H), 7.46 (t, 1H, J ) 7.14 Hz), 7.58 (t, 1H, J ) 7.4 Hz), 7.62
(d, 2H, J ) 8.8 Hz), 7.96 (d, 1H, J ) 8.5 Hz), 8.13 (d, 1H, J )
8.2 Hz), 8.2 (d, 2H, J ) 8.8 Hz); 13C NMR δ 14.5, 64.7, 78.6,
85.6, 86.0, 111.0, 120.2, 123.6, 124.6, 127.4, 128.1, 131.1, 132.8,
146.7, 147.8; MS m/z 278 (M - NO2, 8), 176 (100). Anal. Calcd
for C17H14N4O3: C, 63.35; H, 4.38; N, 17.38. Found: C, 63.31;
H, 4.41; N, 17.05.
Compounds 314 and 7a ,d 20 were prepared by the literature
methods. All of the other starting materials were supplied
by Aldrich Chemical Co. or Fisher and used without further
purification.
Gen er a l P r oced u r e for th e P r ep a r a tion of Com p ou n d s
5 a n d 12. A mixture of vinyl triflates, vinyl halides, or aryl
iodides (1.1 mmol), 1-(benzotriazol-1-yl)propargyl ethyl ether
(3) (0.2 g, 1.0 mmol), PdCl2(PPh3)2 (20 mg, 0.028 mmol), CuI
(10 mg, 0.037 mmol), Et3N (4 mL), and toluene (2 mL) was
stirred at 50 °C for 1 day. After evaporation of the solvent
under vacuum, the residue was dissolved in CH2Cl2 (40 mL)
and sequentially washed with saturated Na2CO3 solution (5
mL) and saturated NH4Cl solution (5 mL). The organic layer
was dried over MgSO4 and evaporated in vacuo to give a
residue which was purified by column chromatography (elu-
ent: hexane-ethyl acetate) to afford the desired product.
1-(Ben zotr ia zol-1-yl)-3-(1-cycloh exen yl)p r op a r gyl eth -
yl eth er (5a ): colorless oil; 1H NMR δ 1.15 (t, 3H, J ) 6.9
Hz), 1.56-1.61 (m, 4H), 2.07-2.11 (m, 4H), 3.35-3.50 (m, 1H),
3.60-3.75 (m, 1H), 6.22 (s, 1H), 6.92 (s, 1H), 7.43 (t, 1H, J )
7.2 Hz), 7.53 (t, 1H, J ) 7.2 Hz), 7.99 (d, 1H, J ) 8.4 Hz), 8.08
(d, 1H, J ) 8.7 Hz); 13C NMR δ 14.5, 21.1, 21.9, 25.5, 28.4,
64.2, 78.8, 79.0, 90.0, 111.6, 119.0, 119.8, 124.2, 127.5, 131.2,
137.8, 146.7; MS m/z 281 (M+, 75), 77 (100); HRMS (EI) calcd
for C17H19N3O 281.1528, found 281.1525.
1-(1-Cycloh exen yl)-3-(b en zot r ia zol-1-yl)-3-et h oxy-1-
n on yn e (8a ). A mixture of 5a (0.5 g, 1.6 mmol) and 1-bro-
mohexane (0.32 g, 1.9 mmol) in THF (20 mL) and HMPA (4
mL) was cooled to -78 °C, and LiHMDS (1.9 mL, 1.9 mmol in
hexane) was added. After 15 min at this temperature, water
(10 mL) was added to quench the reaction, which was then
extracted with ether. After evaporating the solvent, the
residue was purified by column chromotography (eluent:
hexane-ethyl acetate ) 100:3) to give 8a as a colorless oil:
1H NMR δ 0.81 (t, 3H, J ) 6.6 Hz), 1.14 (t, 3H, J ) 7.2 Hz),
1.16-1.20 (m, 8H), 1.58-1.68 (m, 4H), 2.12-2.14 (m, 4H), 2.39
(t, 2H, J ) 6.9 Hz), 3.12-3.17 (m, 1H), 3.78-3.84 (m, 1H),
6.32 (m, 1H), 7.35 (t, 1H, J ) 8.1 Hz), 7.45 (t, 1H, J ) 7.2 Hz),
7.95 (d, 1H, J ) 8.4 Hz), 8.05 (d, 1H, J ) 8.1 Hz).
1-(Ben zot r ia zol-1-yl)-1-et h oxy-5-p h en yl-4-p en t en -2-
1
yn e (5b): colorless oil; H NMR δ 1.18 (t, 3H, J ) 6.9 Hz),
3.40-3.46 (m, 1H), 3.64-3.70 (m, 1H), 6.16 (dd, 1H, J ) 1.5,
16.2 Hz), 6.98 (d, 1H, J ) 1.2 Hz), 7.02 (d, 1H, J ) 16.5 Hz),
7.26-7.38 (m, 5H), 7.43 (t, 1H, J ) 7.8 Hz), 7.57 (t, 1H, J )
Gen er a l P r oced u r e for th e P r ep a r a tion of Com p ou n d s
9a -g a n d 10. The corresponding intermediate 8 was pre-
pared using the procedure for 8a . Then crude 8 was dissolved
in ethanol (20 mL), and concentrated HCl (1 mL) was added.
The solution was stirred at rt for 30 min. Again, after water
(20 mL) was added, the solution was extracted with ether (3
× 100 mL), washed with saturated NaCl (10 mL) solution, and
dried over MgSO4. Chromatography on silica gel (eluent:
hexane-ethyl acetate) afforded the desired product.
7.2 Hz), 7.99 (d, 1H, J ) 8.4 Hz), 8.09 (d, 1H, J ) 8.1 Hz); 13
C
NMR δ 14.6, 64.4, 79.0, 82.9, 87.5, 105.8, 111.6, 120.0, 124.4,
126.5, 127.8, 128.7, 129.2, 131.2, 135.4, 144.1, 146.8. Anal.
Calcd for C19H17N3O: C, 75.21; H, 5.65; N, 13.86. Found: C,
74.92; H, 5.84; N, 13.87.
1-(Be n zot r ia zol-1-yl)-1-e t h oxy-5-(t r im e t h ylsilyl)-4-
p en ten -2-yn e (5c): colorless oil; 1H NMR δ -0.01 (s, 9H),
1.07 (t, 3H, J ) 7.2 Hz), 3.28-3.38 (m, 1H), 3.50-3.60 (m, 1H),
5.88 (d, 1H, J ) 19.2 Hz), 6.57 (d, 1H, J ) 19.2 Hz), 6.85 (s,
1H), 7.35 (t, 1H, J ) 7.2 Hz), 7.45 (t, 1H, J ) 7.2 Hz), 7.88 (d,
1H, J ) 8.4 Hz), 8.99 (d, 1H, J ) 8.1 Hz); 13C NMR δ -1.9,
14.5, 64.3, 78.9, 81.4, 88.1, 111.5, 119.9, 121.2, 124.3, 127.7,
130.9, 146.7, 149.5; MS m/z 299 (M+, 5), 181 (100). Anal.
Calcd for C16H21N3OSi: C, 64.18; H, 7.07; N, 14.04. Found:
C, 64.06; H, 7.25; N, 14.01.
1-(1-Cycloh exen yl)-1-n on yn -3-on e (9a ): colorless oil; 1H
NMR δ 0.89 (t, 3H, J ) 6.9 Hz), 1.29-1.32 (m, 6H), 1.61-1.67
(m, 6H), 2.15-2.19 (m, 4H), 2.55 (t, 2H, J ) 7.5 Hz), 6.43-
6.46 (m, 1H); 13C NMR δ 13.9, 21.1, 21.9, 22.4, 24.2, 26.0, 28.3,
28.6, 31.5, 45.4, 86.1, 93.1, 118.9, 142.1, 188.5; HRMS (EI)
calcd for C15H22O 218.1670, found 218.1693.
1-P h en yl-1-h exen -3-yn -5-on e (9b): colorless oil; 1H NMR
δ 2.0 (s, 3H), 5.84 (d, 1H, J ) 16.2 Hz), 6.83 (d, 1H, J ) 16.5
Hz), 6.95-7.10 (m, 5H); 13C NMR δ 32.6, 90.0, 90.2, 105.1,
126.9, 128.9, 130.0, 135.0, 147.7, 184.4; MS m/z 170 (M+, 30),
127 (100); HRMS (EI) calcd for C12H10O 170.0732, found
170.0733.
1-(Ben zotr iazol-1-yl)-3-(1-cyclopen ten yl)pr opar gyl eth -
1
yl eth er (5d ): colorless oil; H NMR δ 1.16 (t, 3H, J ) 6.6
Hz), 1.84-1.94 (m, 2H), 2.38-2.52 (m, 4H), 3.39-3.44 (m, 1H),
3.62-3.68 (m, 1H), 6.18 (d, 1H, J ) 1.5 Hz), 6.94 (s, 1H), 7.41
(t, 1H, J ) 7.2 Hz), 7.53 (t, 1H, J ) 7.2 Hz), 7.98 (d, 1H, J )
8.4 Hz), 8.09 (d, 1H, J ) 8.1 Hz); 13C NMR δ 14.5, 23.1, 23.3,
35.8, 64.3, 78.9, 82.4, 85.8, 111.6, 119.9, 122.6, 124.3, 127.7,
131.2, 141.2, 146.7; HRMS (EI) calcd for C16H17N3O 267.1372,
found 267.1372.
1-P h en yl-1-h ep ten -3-yn -5-on e (9c): colorless oil; 1H NMR
δ 1.2 (t, 3H, J ) 7.5 Hz), 2.64 (q, 2H, J ) 7.5 Hz), 6.23 (d, 1H,
J ) 16.2 Hz), 7.21 (d, 1H, J ) 15.6 Hz), 7.36-7.56 (m, 5H);
13C NMR δ 8.2, 38.7, 78.6, 89.6, 105.3, 110.6, 126.9, 128.9,
129.9, 135.2, 147.5, 190.1; HRMS (EI) calcd for C13H12
184.0889, found 184.0920.
O
1-(Ben zot r ia zol-1-yl)-3-p h en ylp r op a r gyl et h yl et h er
(12a ):14 white solid, mp 69-70 °C (lit.14 mp 69-70 °C); 1H
NMR 1.19 (t, 3H, J ) 9.0 Hz), 3.40-3.50 (m, 1H), 3.65-3.75
(m, 1H), 7.04 (s, 1H), 7.30-7.50 (m, 6H), 7.54 (t, 1H, J ) 7.1
Hz), 8.04 (d, 1H, J ) 8.3 Hz), 8.09 (d, 1H, J ) 8.3 Hz).
1-(Ben zotr iazol-1-yl)-3-(4-m eth ylph en yl)pr opar gyl eth -
1-P h en yl-1-n on en -3-yn -5-on e (9d ): colorless oil; 1H NMR
δ 0.95 (t, 3H, J ) 7.5 Hz), 1.35-1.43 (m, 2H), 1.68-1.73 (m,
2H), 2.62 (t, 2H, J ) 7.2 Hz), 6.24 (d, 1H, J ) 16.2 Hz), 7.21
(d, 1H, J ) 16.5 Hz), 7.36-7.46 (m, 5H); 13C NMR δ 13.9, 22.2,
26.3, 45.2, 89.9, 90.3, 105.3, 126.9, 128.9, 130.0, 135.2, 147.6,
188.2; MS m/z 212 (M+, 10), 127 (100); HRMS (EI) calcd for
C15H16O 212.1201, found 212.1197.
1
yl eth er (12b): colorless oil; H NMR δ 1.19 (t, 3H, J ) 6.8
Hz), 2.34 (s, 3H), 3.46-3.49 (m, 1H), 3.67-3.70 (m, 1H), 7.02
(s, 1H), 7.12 (d, 2H, J ) 8.1 Hz), 7.35 (d, 2H, J ) 7.8 Hz), 7.43
(t, 1H, J ) 6.9 Hz), 7.55 (t, 1H, J ) 7.5 Hz), 8.04 (d, 1H, J )
1-P h en yl-1-p en ta d ecen -3-yn -5-on e (9e): colorless oil; 1H
NMR δ 0.88 (t, 3H, J ) 6.04 Hz), 1.26-1.30 (m, 14H), 1.68-
1.70 (m, 2H), 2.63 (t, 2H, J ) 7.42 Hz), 6.24 (d, 1H, J ) 16.2
Hz), 7.22 (d, 1H, J ) 16.4 Hz), 7.34-7.44 (m, 5H); 13C NMR δ
(20) Stang, P. J .; Treptow, W. Synthesis 1980, 283.

8204 J . Org. Chem., Vol. 62, No. 23, 1997
Katritzky et al.
14.2, 22.7, 24.3, 29.1, 29.4, 29.5, 29.6, 31.9, 45.5, 89.9, 90.3,
105.3, 127.0, 129.0, 130.1, 135.2, 147.6, 188.2; MS m/z 212 (M+,
10), 127 (100); HRMS (EI) calcd for C21H28O 296.2140, found
296.2130.
over 5 min. After 10 min, an alkyl halide was added and the
mixture was stirred at this temperature for 10 min. Water
(10 mL) was added to quench the reaction. The crude product
obtained was dissolved in ethanol (20 mL) with concentrated
HCl (1 mL), and the mixture was stirred at rt for 30 min. After
ether extraction and chromatography on silica gel, pure
compounds 13 were obtained.
1-(Tr im eth ylsilyl)-6-ph en yl-1-h exen -3-yn -5-on e (9f): col-
1
orless oil; H NMR δ 0.10 (s, 9H), 3.86 (s, 2H), 5.99 (d, 1H, J
) 19.5 Hz), 6.74 (d, 1H, J ) 19.5 Hz), 7.24-7.35 (m, 5H); 13C
NMR δ -2.0, 52.1, 87.3, 91.9, 120.6, 127.3, 128.7, 129.7, 133.0,
154.2, 185.1; MS m/z 241 (M+ - 1, 12), 123 (100); HRMS (EI)
calcd for C15H18O 242.1127, found 242.1101.
1-(4-Meth ylp h en yl)-1-n on yn -3-on e (13a ): colorless oil;
1H NMR δ 0.89 (t, 3H, J ) 6.9 Hz), 1.24-1.78 (m, 8H), 2.39 (s,
3H), 2.65 (t, 2H, J ) 7.5 Hz), 7.19 (d, 2H, J ) 6.9 Hz), 7.46 (d,
2H, J ) 6.9 Hz); 13C NMR δ 14.0, 21.6, 22.4, 24.2, 28.7, 31.5,
45.5, 87.8, 91.2, 117.8, 129.4, 133.0, 141.3, 188.2; HRMS (EI)
calcd for C16H20O + H 229.1592, found 229.1653.
1-(Tr im eth ylsilyl)-1-d od ecen -3-yn -5-on e (9g): colorless
oil; 1H NMR δ 0.19 (s, 9H), 0.96 (t, 3H, J ) 7.5 Hz), 1.21-1.62
(m, 10H), 2.49 (t, 2H, J ) 7.5 Hz), 6.10 (d, 1H, J ) 19.8 Hz),
6.85 (d, 1H, J ) 19.5 Hz); 13C NMR δ -1.9, 14.0, 22.6, 24.0,
28.8, 31.5, 45.4, 87.5, 89.9, 120.8, 153.3, 188.2; HRMS (EI)
calcd for C15H26OSi + H 251.1831, found 251.1831.
1-(4-Meth oxyp h en yl)-1-bu tyn -3-on e (13b):21 colorless oil;
1H NMR δ 2.43 (s, 3H), 3.84 (s, 3H), 6.88 (d, 2H, J ) 8.4 Hz),
7.52 (d, 2H, J ) 8.4 Hz); 13C NMR δ 32.5, 55.3, 88.2, 91.4,
111.5, 114.3, 135.0, 161.6, 184.6.
1-P h e n y l-7-(b e n zo t r ia zo l-1-y l)-1-o c t e n -3-y n -5-o n e
1
(10): colorless oil; H NMR δ 1.75 (d, 3H, J ) 6.9 Hz), 3.36
Su p p or t in g In for m a t ion Ava ila b le: 1H and 13C NMR
and HRMS spectra for products 5a ,d , 8a , 9a -g, 10, and 13a
(32 pages). This material is contained in libraries on micro-
fiche, immediately follows this article in the microfilm version
of the journal, and can be ordered from the ACS; see any
current masthead page for ordering information.
(dd, 1H, J ) 6.0, 17.5 Hz), 3.72 (dd, 1H, J ) 7.5, 17.5 Hz),
5.45-5.52 (m, 1H), 6.16 (d, 1H, J ) 16.2 Hz), 7.16 (d, 1H, J )
16.2 Hz), 7.35-7.45 (m, 6H), 7.52 (t, 1H, J ) 7.2 Hz), 7.64 (d,
1H, J ) 8.1 Hz), 8.05 (d, 1H, J ) 8.7 Hz); 13C NMR δ 22.6,
52.0, 52.6, 90.9, 93.9, 106.2, 111.2, 121.5, 125.6, 128.6, 128.8,
130.5, 134.1, 136.5, 147.5, 150.1, 184.8; HRMS (EI) calcd for
C20H17N3O 315.1372, found 315.1436.
J O971234C
Gen er a l P r oced u r e for th e P r ep a r a tion of 13. Com-
pound 12b or 12c (1.0 mmol) in THF (20 mL) was cooled to
-78 °C, and n-BuLi (0.8 mL, 1.2 mmol in hexane) was added
(21) Ali, M.; Razzaq, A.; Kabir, S. H.; Shafiuddin, M. M. Dacca Univ.
Stud. 1981, 79.