Facile coupling of propargylic, allylic and benzylic alcohols with allylsilane and alkynylsilane, and their deoxygenation with Et3SiH, catalyzed by Bi(OTf)3 in [BMIM][BF4] ionic liquid (IL), with recycling and reuse of the IL

Article abstract of DOI:10.1039/c2ob26046h

Allyltrimethylsilane (allyl-TMS) reacts with propargylic alcohols 1a-1d in the presence of 10% Bi(OTf)₃ in [BMIM][BF₄] solvent to furnish the corresponding 1,5-enynes in respectable isolated yields (87-93%) at room temperature. The utility of Bi(OTf)₃ as a superior catalyst was demonstrated in a survey study on coupling of allyl-TMS with 1a employing several metallic triflates (Bi, Ln, Al, Yb) as well as, B(C₆F ₅)₃, Zn(NTf₂)₂ and Bi(NO ₃)₃·5H₂O. Coupling of cyclopropyl substituted propargylic alcohol 1e with allyl-TMS gave the skeletally intact 1,5-enyne and a ring opened derivative as a mixture. Coupling of propargylic/allylic alcohol 1f with allyl-TMS resulted in allylation at both benzylic (2 isomers) and propargylic positions, as major and minor products respectively. The scope of this methodology for allylation of a series of allylic and benzylic alcohols was explored. Chemoselective reduction of a host of propargylic, propagylic/allylic, bis-allylic, allylic, and benzylic alcohols with Et₃SiH was achieved in high yields with short reaction times. The same approach was successfully applied to couple representative propargylic and allylic alcohols with 1-phenyl-2-trimethylsilylacetylene. The recovery and reuse of the ionic liquid (IL) was gauged in a case study with minimal decrease in isolated yields after six cycles.

Full text of DOI:10.1039/c2ob26046h

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PAPER
Facile coupling of propargylic, allylic and benzylic alcohols with allylsilane
and alkynylsilane, and their deoxygenation with Et3SiH, catalyzed by
Bi(OTf)3 in [BMIM][BF4] ionic liquid (IL), with recycling and reuse of the IL
G. G. K. S. Narayana Kumar and Kenneth K. Laali*
Received 30th May 2012, Accepted 12th July 2012
DOI: 10.1039/c2ob26046h
Allyltrimethylsilane (allyl-TMS) reacts with propargylic alcohols 1a–1d in the presence of 10% Bi(OTf)3
in [BMIM][BF4] solvent to furnish the corresponding 1,5-enynes in respectable isolated yields (87–93%)
at room temperature. The utility of Bi(OTf)3 as a superior catalyst was demonstrated in a survey study on
coupling of allyl-TMS with 1a employing several metallic triflates (Bi, Ln, Al, Yb) as well as, B(C6F5)3,
Zn(NTf2)2 and Bi(NO3)3·5H2O. Coupling of cyclopropyl substituted propargylic alcohol 1e with
allyl-TMS gave the skeletally intact 1,5-enyne and a ring opened derivative as a mixture. Coupling of
propargylic/allylic alcohol 1f with allyl-TMS resulted in allylation at both benzylic (2 isomers) and
propargylic positions, as major and minor products respectively. The scope of this methodology for
allylation of a series of allylic and benzylic alcohols was explored. Chemoselective reduction of a host of
propargylic, propagylic/allylic, bis-allylic, allylic, and benzylic alcohols with Et3SiH was achieved
in high yields with short reaction times. The same approach was successfully applied to couple
representative propargylic and allylic alcohols with 1-phenyl-2-trimethylsilylacetylene. The recovery and
reuse of the ionic liquid (IL) was gauged in a case study with minimal decrease in isolated yields after six
cycles.
main group metals to bring about allylation and deoxygentation
Introduction
was shown by using Ca(NTf2)2/Bu4NBF4 system.10,11
Coupling of π-activated alcohols (propargylic, allylic, and
benzylic) with silicon-based carbanion equivalents, in particular
allylsilanes and alkynylsilanes, is an area of substantial current
interest. Direct coupling of the propargylic alcohols is of particu-
lar interest since it enables the assembly of enynes and diynes in
a one-pot approach. Early studies demonstrated the viability of
these transformations by employing rhenium,1 ruthenium,2,3 and
Au(III) catalysts,4a,b with mixtures of rhenium and gold catalysts
reported to give higher yields.2 The ruthenium catalyst was also
employed in reduction of propargylic systems with silanes.3 The
utility of a heterobimetallic “Pd–Sn” catalyst system has also
been recognized.5 These reactions are typically carried out in
MeNO2, DCE, or DCM, and in the case of rhenium-oxo catalyst
require a co-catalyst.1 The reported BCl3-mediated reaction of
the alkoxides (n-BuLi/DCM) with allyl-TMS represents a differ-
ent approach to the generation of propargylic cations for reaction
with allylsilanes.6
In addition to these reports several studies on coupling of
allylic and benzylic alcohols with allylsilanes have appeared,
using various Lewis and Brønsted acids, namely BiCl3,12
ZrCl4,13 ion-exchanged montmorillonite,14 phosphomolybdic
acid,15 FeCl3·6H2O,16 and HN(SO2F)2.17
Despite the availability of these earlier methods, development
of high yielding approaches that employ readily available cata-
lysts in combination with non-volatile solvents that can be
recycled and reused is highly desirable.
In continuation of our work on electrophilic and onium ion
chemistry in ionic liquids (ILs),18 and in relation to recent
studies from our laboratory focusing on generation and chemistry
of propargylic cations in ILs,19 we describe herein efficient
allylation (with allyl-TMS), reduction (with Et3SiH), and
alkynylation (with alkynyl-TMS) methods for a wide range of
propargylic, allylic, and benzylic alcohols.
Several other Lewis acid catalysts have also been used,
namely Cu(BF4)2,7 Sc(OTf)3,7 FeCl3,8 and iodine,9 typically
employing MeCN and DCM as solvent. The potential of early
Results and discussion
Activation of propargylic alcohols with metallic triflate/ionic
liquid systems for arene propargylation and for the facile assem-
bly of propargylic ethers was demonstrated in earlier works from
this laboratory,19a and in other studies bismuth nitrate/IL system
Department of Chemistry, University of North Florida, 1 UNF Drive,
Jacksonville, FL 32224, USA
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proved efficient in propargylation of 1,3-diketones,19b as well as
indoles, and carbazole.19c The finding that “tamed” propargylic
cations can be generated selectively in the IL media under mild
conditions for coupling to various nucleophiles provided the
impetus for the present study to examine coupling of propargylic
alcohols with allyl-TMS 2, the alkynylsilane 3, and their deoxy-
genation with Et3SiH 4. This project was then extended to
include a host of allylic, and benzylic alcohols.
Using the coupling reaction of propargylic alcohol ( )-1a with
allylsilane 2 as a standard reaction (Fig. 1), and with [BMIM]-
[BF4] as solvent, the efficiency of a series of metallic triflates
(Ln, Bi, Al, Yb) as well as B(C6F5)3, Bi(NO3)3, and Zn (NTf2)2
were explored. For comparison, the reaction was also carried out
in the absence of Lewis acid in [BMIM][BF4], [nitro-BMIM]-
[NTf2]2,19b and in ethylammonium nitrate (EAN) (Table 1).
This comparative study indicated that whereas several catalytic
systems were functional, Bi(OTf)3 was superior to all of them.
Based on the experiments performed without an added Lewis
acid (runs 9–11), [nitro-BMIM][NTf2] ionic liquid showed
potential, but with the goal to perform these reaction at r.t. to
avoid side reactions, it was not selected for further study.
A control experiment performed in 1,2-DCE as solvent employ-
ing 10 mol% Bi(OTf)3 (run 12) gave a lower isolated yield
relative to run 5. Based on the results summarized in Table 1,
10 mol% of Bi(OTf)3 dissolved in [BMIM][BF4] solvent was
selected as an optimum system for subsequent studies.
87–93% isolated yields (Table 2). Reaction of the cyclopropyl-
substituted alcohol 1e gave a mixture of skeletally intact 1,5-
enyne 9 and the ring-opened derivative 10, in 1.0 : 0.68 ratio by
NMR. Coupling of propargylic/allylic alcohol 1f with allyl-TMS
resulted in allylation at both benzylic (11 and 13) and propargylic
positions (12), as major and minor products respectively. The
trans to cis isomeric ratio was measured as 1.0 to 0.36 by NMR.
It is noteworthy that no allenyl-derived products, which were
observed earlier in some transition metal catalyzed reactions,1,11
and no bicyclic products derived from cycloisomerization of 1,5-
enynes,4b were found in present study. The propargyl alcohol 1g
did not couple with allyl-TMS, instead the bis-propargylic ether
14 was isolated.19a Except for the runs 1, 5, and 6 reactions were
performed in recycled IL, and judging from the isolated yields,
this had only a minimal effect on the conversions (see Table 2).
At this point in the study it was necessary to establish the
effect of recycling and re-use of the IL on the isolated yields
over many cycles. The reaction shown in Fig. 1 was selected as
benchmark for this purpose and the process was repeated for six
cycles. The results, given in Table 3, show very small effects on
the isolated yields and are therefore quite encouraging.
In the next phase of the study the scope of the method for
coupling of allylic and benzylic alcohols with allyl-TMS was
examined. The bis-allylic alcohol 1h gave the skeletally intact
coupling product 16 and the isomeric derivative 15, in 0.42 : 1.0
ratio by NMR, providing strong indication for the formation of a
doubly-allylic carbocation and its rearrangement to a benzylic/
allylic carbocation. The allyl-derivatives 17 and 18 were formed
in high yields from alcohols 1i and 1j, and the cyclopropyl
derivative 1k gave the skeletally intact allyl derivative 19. Com-
pound 20 obtained from alcohols 1l is interesting as it shows that
allylation is accompanied by efficient alkylation at C-5 by an
α-thiophenyl-carbocation. By increasing the allyl-TMS to
alcohol ratio the “normal” coupling product 21 was isolated as a
minor product (see Table 4). The benzylic alcohols 1m and 1n
gave the expected coupling products 22 and 23. It is noteworthy
that except for runs 1, 5, and 6 (Table 4) where fresh IL was
employed other runs were performed in recycled IL.
Reaction of propargylic alcohols 1b, 1c, and 1d with allyl-
TMS gave the corresponding 1,5-enynes (6, 7, and 8) in
Fig. 1 Coupling reaction selected for the survey study.
Table 1 Screening of Lewis acid/IL systems as catalysts for the
synthesis of ( )-5
Attention was then focused on hydride transfer from Et3SiH 4
to propagylic, allylic, and benzylic carbocations via alcohols
with Bi(OTf)3/[BMIM][BF4], and the results are summarized in
Table 5. Propargylic alcohols 1a and 1b gave the corresponding
skeletally intact alkynes 24 and 25. Whereas the predominant
product of deoxygenation of the cyclopropyl-substituted alcohol
1e was the intact hydrocarbon 26, minor amounts of the ring
opened product 27 was also detected by NMR. As was the case
in coupling with allyl-TMS (Table 2), deoxygenation of the pro-
pargylic/allylic alcohols 1f gave a mixture of three products,
with predominant products arising from hydride transfer to the
benzylic position to form skeletally rearranged isomeric hydro-
carbons 28 and 29, together with the skeletally intact hydro-
carbon 30. The product ratios were estimated by NMR as
2.0 : 0.29 : 0.12 respectively. A similar chemoselectivity was
observed in deoxygenation of alcohol 1h, forming an isomeric
mixture of hydrocarbons 31 and 33, along with the skeletally
intact 32 as a minor component. Reaction of α-cyclopropyl-
alcohol 1k gave only the skeletally intact hydrocarbon 34, and
reaction of alcohols 1i, and 1n proceeded in high yields to
furnish the corresponding hydrocarbons.
Screen No Lewis acid
IL and molecular solvent Isolated yield (%)
1
2
3
4
5
Ln(OTf)3
Al(OTf)3
Yb(OTf)3
Bi(OTf)3
Bi(OTf)3
[BMIM][BF4]
[BMIM][BF4]
[BMIM][BF4]
[BMIM][BF4]
[BMIM][BF4]
66
46
66
80
93
39
63
12
Trace
9
a
6
7
Bi(NO3)3·5H2O [BMIM][BF4]
B(C6F5)3
[BMIM][BF4]
[BMIM][BF4]
[C2H5NH3][NO3]
[BMIM][BF4]
8
9
10
Zn(NTf2)2
—
—
b
b
b
11
—
26
12
Bi(OTf)3
1,2-DCE
82
a 5 mol% of Lewis acid. All reactions were carried out on a 1 mmol
scale with 10 mol% of Lewis acid in 3.5 mL of fresh ionic liquid at
room temperature and monitored for 30 min. b Reaction carried out
without Lewis acid.
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a,b
Table 2 Reaction of propargylic alcohols with allyltrimethylsilane (2) with Bi(OTf)3 in (bmim) BF4
Entry
1
Alcohol
Products
Time (min)
30
Isolated yield (%)
93
2
3
20
30
90
89
4
5
25
60
87
76
6
7
30
30
86
89
a Fresh (bmim) BF4 was used in runs 1, 5 and 6, whereas recycled IL was used in others. b The (bmim) BF4 could be reused without purification for
up to three runs, after which it was purified and reused.
propargyl alcohols 1a and 1c and allylic alcohol 1i. The corres-
ponding 1,5-diynes 37 and 38 and the 1,5-enyne 39 were
obtained in very good isolated yields and short reaction times
(Table 6).
Table 3 Recovery and reuse of (bmim) BF4
In summary, we have shown that Bi(OTf)3 in [BMIM][BF4]
solvent is an efficient catalytic system for allylation, alkynylation
and deoxygenation of propagylic, allylic and benzylic alcohols.
Reactions are performed at room temperature and generally give
very good isolated yields, typically in less than an hour. These
attributes coupled to the added advantage of recycling and reuse
of the IL make this a superior method for the synthesis of 1,5-
enynes, 1,5-diynes and a host of other functional building
blocks.
No. of cycles
Isolated yield (%)
1
2
3
4
5
6
93
92
92
91
90
88
Experimental
The last part of the study dealt with alkynylation of π-acti-
vated alcohols with 1-phenyl-2-trimethylacetylene 3 using Bi-
(OTf)3/[BMIM][BF4] to synthesize 1,5-diynes and 1,5-enynes.
The feasibility was demonstrated in selected cases with
General
The metallic triflates, bismuth nitrate and tris(pentafluorophenyl)-
borane were high purity commercially available samples and
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a,b
Table 4 Reaction of allylic and benzylic alcohols with allyltrimethylsilane (2) with Bi(OTf)3 in (bmim) BF4
Entry
1
Alcohol
Products
Time (min)
20
Isolated yield (%)
85
2
3
20
25
94
94
4
55
30
30
91
5
84
6c
76 : 16
7
8
20
60
92
86
a Fresh (bmim) BF4 was used in runs 1, 5 and 6, whereas recycled IL was used in others. b The (bmim) BF4 could be reused without purification for
up to three runs, after which it was purified and reused. c 2.2 equi. of allyltrimethylsilane.
were used as received. Ethylammonium nitrate (EAN)18e and the
nitro-IL [3-butyl-1-ethyl-4-nitroimidazolium bis(trifluoromethyl-
sulfonyl)imide]19b were prepared as previously reported. The
propargylic alcohols (1a, 1d & 1g), benzylic alcohols (1i, 1m &
1n), allyltrimethyl silane 2, triethylsilane 3, and 1-phenyl-
cm−1) were recorded on a SHIMADZU FT-IR spectropho-
tometer. GC analysis were performed on a Hewlett-Packard (HP)
gas chromatograph model 5890 series II equipped with a split/
splitless injector and a capillary RTX-5 column. GC-MS ana-
lyses were performed on HP 5890 series II GC/HP 5972 series
mass spectrometer.
2-trimethylsilylacetylene
4 were purchased from ACROS,
ALDRICH and ALFA-AESAR and were used without further
purification. The other propargylic alcohols and benzylic alco-
hols were prepared as previously reported.20 Reactions were
carried out in oven-dried small Schlenk tubes under nitrogen.
Column chromatography separations were performed on silica
gel (200–400 mesh). In some cases preparative TLC was
employed to isolate the products.
General procedure
The ionic liquid (for liquid reactants: 3.5 mL; 18.7 mmol; IL
mole fraction = 0.8904 – for solid reactants: 4.0 mL; 21.4 mmol;
IL mole fraction = 0.9029) was charged into an oven-dried
Schlenk tube under a nitrogen atmosphere and Bi(OTf)3 (10 mol%)
was added and upon sonication (for about 15 min) was dissolved
in the IL. The respective alcohol (1.0 mmol) was then introduced
into the Schlenk tube under a nitrogen atmosphere followed by
the desired silyl nucleophile (1.2 mmol). The reaction mixture
was magnetically stirred, until completion (as monitored by
Melting points were recorded with a MEL-TEMP apparatus
and are uncorrected.
NMR spectra were recorded in CDCl3 (1H at 500 MHz; 13C at
125 MHz) on a Varian 500 NMR instrument (chemical shifts
1
were referenced to internal solvent signals: for CDCl3 – H at
7.26 ppm/13C at 77.16 ppm). IR spectra (solution in CHCl3,
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a,b
Table 5 Reaction of alcohols with triethylsilane (3) with Bi(OTf)3 in (bmim) BF4
Entry
1
Alcohol
Products
Time (min)
15
Isolated yield (%)
95
2
3
20
50
90
80
4
20
92
5
6
30
60
96
83
7
8
15
40
93
91
a Fresh (bmim) BF4 was used in runs 3 and 4, whereas recycled IL was used in others. b The (bmim) BF4 could be reused without purification for up
to three runs, after which it was purified and reused.
TLC). Once the reaction was over, the reaction mixture was
extracted with dry diethyl ether, until the final extraction did not
show a spot corresponding to the starting material or to the
product. The combined organic extracts were washed with DI
water, dried with MgSO4 and concentrated to give the crude
product, which upon purification through column chromato-
graphy furnished the desired products.
(125 MHz; CDCl3): δC 38.70, 42.92, 83.94, 91.08, 117.22,
123.84, 126.97, 127.71, 127.94, 128.34, 128.62, 131.81, 135.60,
141.53 ppm; IR (cm−1, CHCl3): ν 3078, 3062, 3030, 2980,
2931, 2912, 1641, 1597, 1489, 1452, 1442, 1344, 1070, 1029,
995, 914 cm−1; GC-MS: m/z 232 (M+), 191 [(M − 41)+, 100%].
1-Methoxy-4-(1-phenylhex-5-en-1-yn-3-yl)benzene (6).21 Brown
1
liquid, Yield: 90%. H NMR (500 MHz, CDCl3): δH 2.55–2.58
(m, 2H), 3.80 (s, 3H), 3.86 (t, J = 7.0 Hz, 1H), 5.05–5.12
(m, 2H), 5.86–5.94 (m, 1H), 6.87 (d, J = 9.0 Hz, 2H), 7.25–7.29
(m, 3H), 7.33 (d, J = 9.0 Hz, 2H), 7.42–7.44 (m, 2H) ppm;
13C NMR (125 MHz, CDCl3): δC 37.71, 42.88, 55.29, 83.60,
91.28, 113.86, 117.02, 123.74, 127.76, 128.19, 128.54, 131.65,
133.51, 135.55, 158.46 ppm; IR (cm−1, CHCl3): ν 3076, 3062,
3003, 2954, 2933, 2910, 1600, 1585, 1512, 1442, 1303, 1247,
1174, 1111, 1033, 995, 916, 831, 758 cm−1; GC-MS: m/z
262 (M)+.
Re-use and recycling of IL
After extraction, the ionic liquid was dried under high-vacuum at
60–70 °C for about 6 hours and re-used in successive runs.
Hex-5-en-1-yne-1,3-diyldibenzene (5).1 Pale yellow liquid,
Yield: 93%. 1H NMR (500 MHz; CDCl3): δH 2.57–2.60 (m,
2H), 3.91 (t, J = 7.0 Hz, 1H), 5.06–5.12 (m, 2H), 5.87–5.95 (m,
1H), 7.23–7.35 (m, 6H), 7.41–7.45 (m, 4H) ppm; 13C NMR
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a
Table 6 Reaction of alcohols with 1-phenyl-2-trimethylsilylacetylene (4) with Bi(OTf)3 in (bmim) BF4
Entry
1
Alcohol
Products
Time (min)
50
Isolated yield (%)
87
2
3
40
50
91
89
a Fresh (bmim) BF4 was used.
1-Methyl-4-(3-phenylhex-5-en-1-ynyl)benzene (7). Yellow
liquid, Yield: 89%. H NMR (500 MHz, CDCl3): δH 2.32 (s,
1.95, 3.52, 20.44, 47.16, 47.92, 85.80, 90.24, 117.53, 123.72,
126.14, 126.94, 128.25, 128.36, 128.51, 131.83, 134.86,
138.70 ppm; IR (cm−1, CHCl3) (inseparable mixtures): ν 3078,
3028, 2920, 2862, 1722, 1683, 1674, 1604, 1510, 1448, 1315,
1
3H), 2.57 (t, J = 7.0 Hz, 2H), 3.89 (t, J = 7.0 Hz, 1H), 5.05–5.11
(m, 2H), 5.88–5.94 (m, 1H), 7.09 (d, J = 8.0 Hz, 2H), 7.22–7.25
(m, 1H), 7.31–7.34 (m, 4H), 7.41 (d, J = 8.0 Hz, 2H) ppm; 13C
NMR (125 MHz, CDCl3): δC 21.56, 38.69, 42.98, 83.96, 90.25,
117.16, 120.72, 126.91, 127.71, 128.57, 129.08, 131.66, 135.66,
137.93, 141.64 ppm; IR (cm−1, CHCl3): ν 3078, 3028, 2920,
2862, 1722, 1683, 1674, 1604, 1510, 1448, 1315, 1286, 1278,
1219, 1178, 1107, 1074, 1029, 997, 916, 817 cm−1; GC-MS:
m/z 246 [(M)+, 100%], 220 (M − 41)+.
1286, 1278, 1219, 1178, 1107, 1074, 1029, 997, 916, 817 cm−1
;
GC-MS (isomeric mixture): m/z 272 (M)+.
(Z)-Nona-3,8-dien-1-yne-1,3-diyldibenzene (10). 1H NMR
(500 MHz, CDCl3): δH 1.65 (pentet, J = 7.5 Hz, 2H), 2.14–2.19
(m, 2H), 2.60 (q, J = 7.5 Hz, 2H), 4.97–5.07 (m, 2H), 5.77–5.90
(m, 1H), 6.46 (t, J = 7.5 Hz, 1H), 7.22–7.66 (m, 10H) ppm; 13C
NMR (125 MHz, CDCl3): δC 28.52, 30.98, 33.59, 86.99, 95.33,
114.93, 123.93, 126.65, 127.63, 127.99, 128.32, 128.49, 131.65,
134.86, 138.39, 138.54, 144.76 ppm; IR (cm−1, CHCl3)
(inseparable mixtures): ν 3078, 3028, 2920, 2862, 1722, 1683,
1674, 1604, 1510, 1448, 1315, 1286, 1278, 1219, 1178, 1107,
1074, 1029, 997, 916, 817 cm−1; GC-MS (isomeric mixtures):
m/z 272 (M)+.
Trimethyl(3-phenylhex-5-en-1-ynyl)silane (8).4a Colorless oil,
1
Yield 87%. H NMR (500 MHz, CDCl3): δH 0.18 (s, 9H), 2.52
(tt, J = 7.5, 1.5 Hz, 2H), 3.70 (t, J = 7.5 Hz, 1H), 5.02–5.06 (m,
2H), 5.79–5.87 (m, 1H), 7.21–7.35 (m, 5H) ppm; 13C NMR
(125 MHz, CDCl3): δC 0.30, 39.05, 42.98, 87.94, 107.81,
117.13, 126.89, 127.68, 128.54, 135.44, 141.20 ppm; IR (cm−1
,
CHCl3): ν 3080, 3064, 3030, 2958, 2935, 2899, 2173, 1641,
1600, 1494, 1452, 1440, 1415, 1340, 1328, 1301, 1247, 1076,
1055, 1031, 995, 981, 916, 879, 818, 756 cm−1; GC-MS: m/z
228 (M)+, 191 [(M − 41)+, 100%].
(E)-Octa-3,7-dien-1-yne-1,5-diyldibenzene (11), (E)-(3-allylpent-
1-en-4-yne-1,5-diyl)dibenzene(12) and (Z)-octa-3,7-dien-1-yne-
1,5-diyldibenzene (13)
Yellow liquid, Yield: 86% [in 1.00 : 0.39 : 0.36 ratio (11 : 12 : 13)
by NMR]:
(3-Cyclopropylhex-5-en-1-yne-1,3-diyl)dibenzene (9) and
(Z)-nona-3,8-dien-1-yne-1,3-diyldibenzene (10)
(E)-Octa-3,7-dien-1-yne-1,5-diyldibenzene (11). 1H NMR
(500 MHz, CDCl3): δH 2.54 (t, J = 7.5 Hz, 2H), 3.47 (q, J =
7.0 Hz, 1H), 5.00–5.07 (m, 2H), 5.67 (d, J = 15.5 Hz, 1H),
5.70–5.82 (m, 1H), 6.39 (dd, J = 7.5, 15.5 Hz, 1H), 7.19–7.46
(m, 10H) ppm; 13C NMR (125 MHz, CDCl3): δC 39.78, 49.25,
88.12, 89.21, 110.03, 116.84, 123.59, 126.75, 127.90, 128.12,
Pale yellow liquid, Yield: 76% [pair of isomers in 1.0 : 0.68 ratio
(9 : 10) by NMR]:
(3-Cyclopropylhex-5-en-1-yne-1,3-diyl)dibenzene (9). 1H NMR
(500 MHz, CDCl3): δH 0.37–0.42 (m, 1H), 0.46–0.51 (m, 1H),
0.54–0.60 (m, 1H), 0.75–0.80 (m, 1H), 1.25–1.32 (m, 1H), 2.80
(d, J = 7.0 Hz, 2H), 4.97–5.07 (m, 2H), 5.77–5.90 (m, 1H),
7.22–7.66 (m, 10H) ppm; 13C NMR (125 MHz, CDCl3): δC
128.39, 128.74, 131.56, 136.11, 142.74, 147.04 ppm; IR (cm−1
,
CHCl3) (inseparable mixture): ν 3078, 3061, 3026, 3003, 2978,
7352 | Org. Biomol. Chem., 2012, 10, 7347–7355
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2918, 1639, 1597, 1489, 1452, 1440, 1070, 1029, 993, 956,
116.62, 126.29, 127.28, 128.68, 130.24, 132.49, 136.39,
137.59 ppm; IR (cm−1, CHCl3): ν 3061, 3026, 2954, 2920,
2848, 1641, 1600, 1494, 1448, 1219, 1072, 1029, 987, 966,
912; GC-MS: m/z 260 (M)+, 217 [(M − 41)+, 100%]+.
912, 786, 754; GC-MS (isomeric mixture): m/z 217 (M − 41)+.
(E)-(3-Allylpent-1-en-4-yne-1,5-diyl)dibenzene (12). 1H NMR
(500 MHz, CDCl3): δH 2.49 (t, J = 7.0 Hz, 2H), 3.52 (q, J =
7.0 Hz, 1H), 5.06–5.19 (m, 2H), 5.92–6.01 (m, 1H), 6.21 (dd,
J = 7.0, 15.5 Hz, 1H), 6.71 (d, J = 15.5 Hz, 1H), 7.19–7.46 (m,
10H) ppm; 13C NMR (125 MHz, CDCl3): δC 35.56, 40.33,
84.26, 90.14, 117.33, 123.78, 126.53, 127.52, 128.28, 128.66,
(E)-Hexa-1,5-diene-1,3-diyldibenzene (17).10 Colorless oil,
Yield: 94%. 1H NMR (500 MHz, CDCl3): δH 2.54–2.58 (m,
2H), 3.55 (dd, J = 13.5, 7.0 Hz, 1H), 4.95–5.05 (m, 2H),
5.70–5.78 (m, 1H), 6.30–6.38 (m, 2H), 7.12–7.31 (m, 10H); 13
C
128.71, 129.25, 130.93, 131.81, 135.43, 137.21 ppm; IR (cm−1
,
NMR (125 MHz, CDCl3): δC 40.29, 49.02, 116.46, 126.30,
126.47, 127.23, 127.85, 128.57, 128.62, 129.88, 133.56, 136.61,
137.56, 143.92; IR (cm−1, CHCl3): ν 3080, 3061, 3026, 2924,
1598, 1492, 1448, 1072, 1029, 964, 912, 758 cm−1; GC-MS:
m/z 193 [(M − 41)+, 100%].
CHCl3) (isomeric mixture): ν 3078, 3061, 3026, 3003, 2978,
2918, 1639, 1597, 1489, 1452, 1440, 1070, 1029, 993, 956,
912, 786, 754; GC-MS (isomeric mixture): m/z 217 (M − 41)+.
(Z)-Octa-3,7-dien-1-yne-1,5-diyldibenzene (13). 1H NMR
(500 MHz, CDCl3): δH 2.58 (t, J = 7.0 Hz, 2H), 4.13 (q, J = 7.0
Hz, 1H), 5.06–5.19 (m, 2H), 5.73 (d, J = 10.0 Hz, 1H),
5.70–5.82 (m, 1H), 6.06 (t, J = 10.0 Hz, 1H), 7.19–7.46 (m,
10H) ppm; 13C NMR (125 MHz, CDCl3): δC 40.05, 46.36,
86.48, 94.12, 109.17, 116.51, 123.68, 126.55, 127.62, 127.96,
4-(4-Methoxyphenyl)-1-pentene (18).12 Colorless oil, Yield:
94%. 1H NMR (500 MHz, CDCl3): δH 1.22 (d, J = 7.0 Hz, 3H),
2.22–2.35 (m, 2H), 2.72–2.76 (m, 1H), 4.93–5.00 (m, 2H),
5.66–5.73 (m, 1H), 6.84 (d, J = 8.5 Hz, 2H), 7.11 (d, J = 8.5 Hz,
2H); 13C NMR (125 MHz, CDCl3): 21.8, 39.06, 43.02, 55.36,
128.35, 128.47, 131.60, 136.24, 143.52, 146.34 ppm; IR (cm−1
,
113.82, 115.92, 127.97, 137.44, 139.33, 157.90; IR (cm−1
,
CHCl3) (isomeric mixture): ν 3078, 3061, 3026, 3003, 2978,
2918, 1639, 1597, 1489, 1452, 1440, 1070, 1029, 993, 956,
912, 786, 754; GC-MS (isomeric mixture): m/z 217 (M − 41)+.
CHCl3): ν 3074, 2997, 2958, 2926, 2908, 2835, 1639, 1612,
1583, 1512, 1456, 1440, 1300, 1240, 1176, 1035, 993, 912, 827,
806 cm−1; GC-MS: m/z 176 (M)+, 135 [(M − 41)+, 100%].
Bis(1-phenyl-2-propynyl)-ether (14).19b Colorless oil, Yield:
89%. NMR shows the presence of two geometrical isomers in
1 : 0.76 ratio. 1H NMR (500 MHz, CDCl3): δH 2.67 (d, J =
2.2 Hz, 2H), 2.72 (d, J = 2.0 Hz, 2H), 5.27 (d, J = 2.2 Hz, 2H),
5.67 (d, J = 2.0 Hz, 2H), 7.33–7.42 (m, 12H), 7.51–7.59 (m,
8H) ppm; 13C NMR (125 MHz, CDCl3): δC 68.98, 69.49, 76.10,
76.44, 81.13, 81.54, 127.67, 127.88, 128.58, 128.66, 128.77,
128.94, 137.60, 137.83 ppm; IR (cm−1, CHCl3): ν 3286, 3064,
3032, 2875, 2115, 1494, 1452, 1344, 1301, 1267, 1193, 1080,
1001, 958, 912, 842, 823 cm−1; GC-MS: m/z 131 (PhCHO–
CuCH)+, 115 [(PhCH–CuCH)+, 100%].
4-Phenyl-4-cyclopropylbuta-1,2-ene (19).15 Colorless oil,
Yield: 90%. 1H NMR (500 MHz, CDCl3): δH 0.05–0.10 (m,
1H), 0.20–0.25 (m, 1H), 0.35–0.41 (m, 1H), 0.56–0.62 (m, 1H),
0.97–1.02 (m, 1H), 1.86–1.90 (m, 1H), 2.46–2.58 (m, 2H),
4.88–4.99 (m, 2H), 5.68–5.76 (m, 1H), 7.17–7.20 (m, 3H),
7.27–7.30 (m, 2H); 13C NMR (125 MHz, CDCl3): 3.89, 5.77,
17.17, 41.26, 51.12, 115.74, 126.15, 127.77, 128.30, 137.24,
145.35; IR (cm−1, CHCl3): ν 3076, 3062, 3026, 3001, 2978,
2920, 2904, 2877, 1639, 1492, 1452, 1440, 1016, 995,
910, 852, 842, 819, 765 cm−1; GC-MS: m/z 172 (M)+, 131
[(M − 41)+, 100%].
2-(Pent-4-en-2-yl)-5-(1-(thiophen-2-yl)ethyl)thiophene (20). Color-
less liquid, 1H NMR (500 MHz, CDCl3): δH 1.29 (d, J = 6.5 Hz,
3H), 1.75 (d, J = 7.0 Hz, 3H), 2.24–2.30 (m, 1H), 2.40–2.46 (m,
1H), 3.02 (sextet, J = 7.0 Hz, 1H), 4.57 (q, J = 7.0 Hz, 1H),
4.99–5.05 (m, 2H), 5.72–5.80 (m, 1H), 6.61 (d, J = 3.5 Hz, 1H),
6.66 (dd, J = 1.0, 3.5 Hz, 1H), 6.88 (d, J = 3.5 Hz, 1H), 6.93
(dd, J = 3.5, 5.0 Hz, 1H), 7.16 (dd, J = 1.5, 5.0 Hz, 1H) ppm;
13C NMR (125 MHz, CDCl3): δC 22.16, 24.61/24.63, 35.41,
36.47, 43.49, 116.55, 122.01, 123.03, 123.66, 123.76, 126.63,
136.68, 147.16, 149.72, 150.36 ppm; IR (cm−1, CHCl3): ν 3072,
2968, 2924, 2870, 1639, 1452, 1436, 1375, 1284, 1234, 993,
914, 850, 827, 800, 748 cm−1; GC-MS: m/z 262 (M)+, 221
[(M − 41)+, 100%].
(1E,3E)-Octa-1,3,7-triene-1,5-diyldibenzene (15) and
(1E,4E)-3-allylpenta-1,4-diene-1,5-diyl)dibenzene (16)
Pale yellow liquid, Yield: 85% [in 1.00 : 0.42 (15 : 16) ratio by
NMR]:
(1E,3E)-Octa-1,3,7-triene-1,5-diyldibenzene (15). 1H NMR
(500 MHz, CDCl3): δH 2.56 (t, J = 7.0 Hz, 2H), 3.46 (q, J = 7.0
Hz, 1H), 5.00–5.08 (m, 2H), 5.69–5.80 (m, 1H), 5.99 (dd, J =
7.0, 16.0 Hz, 1H), 6.22 (dd, J = 10.5, 16.0 Hz, 1H), 6.48 (d, J =
16.0 Hz, 1H), 6.78 (dd, J = 10.5, 16.0 Hz, 1H), 7.12–7.37 (m,
10H) ppm; 13C NMR (125 MHz, CDCl3): δC 40.30, 48.94,
116.46, 126.32, 126.49, 127.38, 127.86, 128.64, 128.73, 129.20,
130.54, 131.29, 136.64, 137.64, 138.12, 143.92 ppm; IR (cm−1
,
CHCl3) (isomeric mixture): ν 3061, 3026, 2954, 2920, 2848,
1641, 1600, 1494, 1448, 1219, 1072, 1029, 987, 966, 912;
GC-MS (isomeric mixture): m/z 260 (M)+, 217 [(M − 41)+,
100%].
4-(2-Thienyl)-1-pentene (21).22 Colorless liquid, 1H NMR
(500 MHz, CDCl3): δH 1.33 (d, J = 7.0 Hz, 3H), 2.29–2.35
(m, 1H), 2.42–2.48 (m, 1H), 3.08–3.15 (m, 1H), 4.99–5.06
(m, 2H), 5.72–5.80 (m, 1H), 6.80 (m, 1H), 6.92 (dd, J = 3.5,
5.5 Hz, 1H), 7.12 (dd, J = 1.0, 4.5 Hz, 1H) ppm; 13C NMR
(125 MHz, CDCl3): 22.44, 35.27, 43.65, 116.63, 122.66,
122.74, 126.57, 136.61, 151.40 ppm; IR (cm−1, CHCl3): ν 3074,
(1E,4E)-3-Allylpenta-1,4-diene-1,5-diyl)dibenzene (16). 1H NMR
(500 MHz, CDCl3): δH 2.49 (t, J = 7.0 Hz, 2H), 3.14 (pentet,
J = 7.0 Hz, 1H), 5.06–5.14 (m, 2H), 5.84–5.92 (m, 1H), 6.23
(dd, J = 7.0, 15.0 Hz, 2H), 6.46 (d, J = 15.0 Hz, 2H), 7.12–7.37
(m, 10H) ppm; 13C NMR (125 MHz, CDCl3): δC 39.75, 46.13,
2958, 2924, 2914, 1456, 1247, 991, 914, 862, 831, 773 cm−1
;
GC-MS: m/z 152 (M)+, 111 [(M − 41)+, 100%].
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4,4-Diphenyl-1-butene (22).23 Colorless oil, Yield: 91%. 1H
NMR (500 MHz, CDCl3): δH 2.81 (t, J = 7.0 Hz, 2H), 4.00 (t,
J = 7.0 Hz, 1H), 4.93–5.04 (m, 2H), 5.67–5.74 (m, 1H),
7.15–7.28 (m, 10H); 13C NMR (125 MHz, CDCl3): δC 40.09,
(E)-Pent-3-en-1-yne-1,5-diyldibenzene (28). 1H NMR
(500 MHz, CDCl3): δH 3.50 (d, J = 7.0 Hz, 2H), 5.73 (d, J =
16.0 Hz, 1H), 6.38 (dt, J = 7.0, 16.0 Hz, 1H), 7.19–7.47 (m,
10H) ppm; 13C NMR (125 MHz, CDCl3): δC 39.53, 88.10,
88.86, 111.04, 123.58, 126.55, 128.29, 128.40, 128.71, 128.84,
131.57, 138.99, 143.04 ppm; IR (cm−1, CHCl3) (inseparable
mixture): ν 3082, 3061, 3026, 2897, 1595, 1494, 1489, 1452,
1440, 1429, 1267, 1070, 1029, 956, 914, 829; GC-MS (isomeric
mixture): m/z 218 (M)+.
51.39, 116.42, 126.32, 128.09, 128.54, 136.98, 144.64; IR (cm−1
,
CHCl3): ν 3062, 3026, 2924, 1494, 1450, 1219, 1031, 993, 912.
771, 754 cm−1; GC-MS: m/z 208 (M)+, 167 [(M − 41)+, 100%].
4-(4,4,4-Triphenyl)-1-butane (23).15 White solid, m.p.
1
57–59 °C, Yield: 86%. H NMR (500 MHz, CDCl3): δH 3.49
(Z)-Pent-3-en-1-yne-1,5-diyldibenzene(29). 1H NMR (500 MHz,
CDCl3): δH 3.75 (d, J = 7.5 Hz, 2H), 5.80 (d, J = 10.5 Hz, 1H),
6.12 (dt, J = 7.5, 10.5 Hz, 1H), 7.19–7.47 (m, 10H) ppm; 13C
NMR (125 MHz, CDCl3): δC 36.82, 86.34, 93.87, 110.04,
123.59, 126.37, 128.12, 128.29, 128.46, 128.69, 131.57, 139.84,
141.98 ppm; IR (cm−1, CHCl3) (inseparable mixture): ν 3082,
3061, 3026, 2897, 1595, 1494, 1489, 1452, 1440, 1429, 1267,
1070, 1029, 956, 914, 829; GC-MS (isomeric mixture): m/z
218 (M)+.
(dt, J = 1.5, 7.0 Hz, 2H), 4.91–5.04 (m, 2H), 5.60–5.69 (m, 1H),
7.16–7.28 (m, 15H); 13C NMR (125 MHz, CDCl3): δC 45.68,
56.44, 117.37, 126.10, 127.89, 129.56, 136.12, 147.43; IR (cm−1
,
CHCl3): ν 3057, 3032, 2929, 2916, 1492, 1446, 1087, 1035,
1001, 974, 914, 759 cm−1; GC-MS: m/z 243 [(M − 41)+, 100%].
1
1,3-Diphenylpropyne (24).4b Colorless liquid, Yield: 95%. H
NMR (500 MHz, CDCl3): δH 3.82 (s, 2H), 7.22–7.45 (m, 10H)
ppm; 13C NMR (125 MHz, CDCl3): δC 25.89, 82.82, 87.67,
123.86, 126.77, 127.94, 128.11, 128.37, 128.68, 131.79,
136.92 ppm; IR (cm−1, CHCl3): ν 3062, 3030, 2918, 2889,
1950, 1693, 1670, 1597, 1452, 1427, 1417, 1336, 1317, 1292,
1070, 1028, 914 cm−1; GC-MS: m/z 192 (M)+.
(E)-Pent-1-en-4-yne-1,5-diyldibenzene (30).24 1H NMR
(500 MHz, CDCl3): δH 3.36 (d, J = 5.5 Hz, 2H), 6.25 (dt, J =
5.5, 15.5 Hz, 1H), 6.71 (d, J = 15.5 Hz, 1H), 7.19–7.47 (m,
10H) ppm; 13C NMR (125 MHz, CDCl3): δC 23.14, 83.01,
86.89, 123.79, 124.38, 126.41, 127.47, 127.95, 128.29, 128.66,
131.62, 131.77, 137.23 ppm; IR (cm−1, CHCl3) (inseparable
mixture): ν 3082, 3061, 3026, 2897, 1595, 1494, 1489, 1452,
1440, 1429, 1267, 1070, 1029, 956, 914, 829; GC-MS (isomeric
mixture): m/z 218 (M)+.
1-Methoxy-4-(3-phenylprop-2-ynyl)benzene (25).4b Yellow
1
liquid, Yield: 90%. H NMR (500 MHz, CDCl3): δH 3.76 (s,
2H), 3.79 (s, 3H), 6.87 (d, J = 8.5 Hz, 2H), 7.27–7.28 (m, 3H),
7.32 (d, J = 8.5 Hz, 2H), 7.43 (m, 2H) ppm; 13C NMR
(125 MHz, CDCl3): δC 25.01, 55.44, 82.54, 88.12, 114.11,
123.87, 127.89, 128.34, 128.93, 129.06, 131.76, 158.53 ppm;
IR (cm−1, CHCl3): ν 3061, 3003, 2954, 2908, 2835, 1693, 1597,
1508, 1421, 1290, 1247, 1174, 1161, 1033, 831, 812, 756 cm−1
;
(1E,3E)Penta-1,3-diene-1,5-diyldibenzene (31), (1E,4E)-1,5-
diphenylpenta-1,4-diene (32) and (1E,3Z)-penta-1,3-diene-1,5-
diyldibenzene (33)
GC-MS: m/z 222 [(M)+, 100%], 207(M-Methyl)+.
(3-Cyclopropylprop-1-yne-1,3-diyl)dibenzene (26) and (Z)-hex-3-
en-1-yne-1,3-diylbenzene (27)
Yellow Liquid, Yield: 96% [in 2.00 : 0.29 : 0.12 (31 : 32 : 33)
ratio by NMR]:
(1E,3E)-Penta-1,3-diene-1,5-diyldibenzene (31).25 1H NMR
(500 MHz, CDCl3): δH 3.49 (d, J = 6.5 Hz, 2H), 5.97 (dt, J =
6.5, 15.0 Hz, 1H), 6.26 (dd, J = 10.5, 15.0 Hz, 1H), 6.48 (d, J =
15.5 Hz, 1H), 6.78 (dd, J = 10.5, 15.0 Hz, 1H), 7.18–7.38 (m,
10H) ppm; 13C NMR (125 MHz, CDCl3): δC 39.34, 126.31,
126.35, 127.40, 128.63, 128.66, 128.71, 128.78, 129.11, 131.13,
131.84, 137.62, 140.27 ppm; IR (cm−1, CHCl3) (inseparable
mixture): ν 3082, 3061, 3024, 2918, 1724, 1674, 1597, 1554,
1494, 1448, 1429, 1122, 1072, 1028, 989, 968, 910, 842, 779,
744; GC-MS: m/z 220 (M)+, 129 [(M-benzyl)+, 100%].
Pale yellow liquid, Yield: 80% [in 1 : 0.06 (26 : 27) ratio by
NMR]:
(3-Cyclopropylprop-1-yne-1,3-diyl)dibenzene (26). 1H NMR
(500 MHz, CDCl3): δH 0.51–0.59 (m, 4H), 1.13–1.25 (m, 1H),
3.68 (d, J = 7.0 Hz, 1H), 7.23–7.30 (m, 4H), 7.33–7.36 (m, 2H),
7.41–7.44 (m, 2H), 7.47–7.48 (m, 2H) ppm; 13C NMR
(125 MHz, CDCl3): δC 3.26, 4.21, 17.63, 41.44, 83.40, 89.74,
123.80, 126.97, 127.66, 127.91, 128.32, 128.60, 131.82,
142.16 ppm; IR (cm−1, CHCl3): ν 3080, 3062, 3028, 3003,
1689, 1670, 1598, 1489, 1452, 1442, 1276, 1070, 1020,
914 cm−1; GC-MS (isomeric mixture): m/z 232 (M)+.
(1E,4E)-1,5-Diphenylpenta-1,4-diene
(32).26 1H
NMR
(500 MHz, CDCl3): δH 3.12 (t, J = 6.5 Hz, 2H), 6.30 (dt, J =
6.5, 16.0 Hz, 2H), 6.47 (d, J = 16.0 Hz, 2H), 7.18–7.38 (m,
10H) ppm; IR (cm−1, CHCl3) (inseparable mixture): ν 3082,
3061, 3024, 2918, 1724, 1674, 1597, 1554, 1494, 1448, 1429,
1122, 1072, 1028, 989, 968, 910, 842, 779, 744; GC-MS: m/z
220 (M)+.
(Z)-Hex-3-en-1-yne-1,3-diylbenzene (27). 1H NMR (500 MHz,
CDCl3): δH 1.15 (t, J = 7.5 Hz, 3H), 2.58 (pentet, J = 7.5 Hz,
2H), 6.45 (t, J = 7.5 Hz, 1H), 7.23–7.66 (m, 10H) ppm; GC-MS:
m/z 232 (M)+.
(E)-Pent-3-en-1-yne-1,5-diyldibenzene (28), (Z)-pent-3-en-1-yne-
1,5-diyldibenzene (29) and (E)-pent-1-en-4-yne-1,5-
diyldibenzene (30)16
(1E,3Z)-Penta-1,3-diene-1,5-diyldibenzene (33).27 1H NMR
(500 MHz, CDCl3): δH 3.65 (d, J = 8.0 Hz, 2H), 5.69 (dd, J =
8.0, 11.2 Hz, 1H), 6.30 (merged with other isomer, 1H), 6.61 (d,
J = 15.5 Hz, 1H), 7.18–7.38 (m, 10H) ppm; IR (cm−1, CHCl3)
(inseparable mixture): ν 3082, 3061, 3024, 2918, 1724, 1674,
Yellow liquid, Yield: 92% [in 2.00 : 1.11 : 0.42 (28 : 29 : 30) ratio
by NMR]:
7354 | Org. Biomol. Chem., 2012, 10, 7347–7355
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1597, 1554, 1494, 1448, 1429, 1122, 1072, 1028, 989, 968, 910,
References
842, 779, 744; GC-MS: m/z 220 (M)+.
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(Cyclopropylmethyl)benzene (34).28 Colorless oil, Yield:
83%; 1H NMR (500 MHz, CDCl3): δH 0.19–0.22 (m, 2H),
0.50–0.53 (m, 2H), 0.91–1.00 (m, 1H), 2.55 (d, J = 6.5 Hz, 1H),
7.18–7.30 (m, 5H); 13C NMR (125 MHz, CDCl3): δC 4.79,
11.98, 40.49, 125.95, 128.37, 128.49, 142.31; IR (cm−1
,
CHCl3): ν 3076, 3064, 3026, 3003, 2912, 2846, 1494, 1452,
1070, 1016, 769 cm−1; GC-MS: m/z 132 (M)+.
(E)-Pent-1-en-4-yne-1,5-diyldibenzene (35).16 Colorless oil,
Yield: 93%; 1H NMR (500 MHz, CDCl3): δH 3.50 (d, J =
7.0 Hz, 2H), 6.30 (dt, J = 7.0, 15.5 Hz, 1H), 6.42 (d, J =
15.5 Hz, 1H), 7.15–7.32 (m, 10H); 13C NMR (125 MHz,
CDCl3): δC 39.44, 126.24, 126.29, 127.20, 128.60, 128.77,
129.31, 131.19, 137.58, 140.25; IR (cm−1, CH2Cl2): ν 3082,
3061, 3026, 2897, 1600, 1494, 1452, 1429, 1074, 1029, 964,
790 cm−1; GC-MS: m/z 194 (M)+.
6 G. W. Kabalka, M. L. Yao and S. Borella, J. Am. Chem. Soc., 2006, 128,
11320–11321.
7 J. S. Yadav, B. V. S. Reddy, T. S. Rao and K. V. R. Rao, Tetrahedron
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Triphenylmethane (36).29 White solid, m.p. 93–95 °C, Yield:
1
91%; H NMR (500 MHz, CDCl3): δH 5.54 (s, 1H), 7.10–7.12
(m, 6H), 7.18–7.23 (m, 3H), 7.26–7.29 (m, 6H); 13C NMR
(125 MHz, CDCl3): δC 56.99, 126.44, 128.44, 129.60, 144.05;
IR (cm−1, CH2Cl2): ν 3084, 3062, 3022, 1597, 1581, 1492,
1444, 1080, 1029, 920, 754 cm−1; GC-MS: m/z 244 (M)+.
Penta-1,4-diyne-1,3,5-triyltribenzene (37).30 Pale yellow oil,
Yield: 87%; 1H NMR (500 MHz, CDCl3): δH 5.21 (s, 1H),
7.26–7.33 (m, 7H), 7.39–7.42 (m, 2H), 7.47–7.49 (m, 4H),
7.67–7.69 (m, 2H) ppm; 13C NMR (125 MHz, CDCl3): δC
30.08, 82.80, 86.58, 122.97, 127.32, 127.53, 128.21, 128.25,
128.73, 131.82, 137.97 ppm; IR (cm−1, CH2Cl2): ν 3082, 3062,
3032, 2920, 2850, 1597, 1558, 1489, 1452, 1442, 1294, 1070,
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1028, 914 cm−1
.
(5-p-Tolylpenta-1,4-diyne-1,3-diyl)dibenzene (38). Pale yellow
1
oil, Yield: 91%; H NMR (500 MHz, CDCl3): δH 2.34 (s, 3H),
5.20 (s, 1H), 7.11 (d, J = 8.0 Hz, 2H), 7.29–7.31 (m, 4H),
7.37–7.40 (m, 4H), 7.47–7.48 (m, 2H), 7.67 (d, J = 8.0 Hz, 2H),
ppm; 13C NMR (125 MHz, CDCl3): δC 21.61, 30.23, 82.86,
83.06, 85.94, 86.89, 120.04, 123.17, 127.47, 127.63, 128.34,
128.36, 128.85, 129.11, 131.83, 131.96, 138.24, 138.47 ppm; IR
(cm−1, CH2Cl2): ν 3082, 3061, 3028, 2951, 2922, 2852, 2196,
19 (a) G. Aridoss, V. D. Sarca, Jr., J. F. Ponder, J. Crowe and K. K. Laali,
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1510, 1490, 1452, 1442, 1292, 1180, 1029, 914, 815, 756 cm−1
.
(E)-Pent-1-en-4-yne-1,3,5-triyltribenzene (39).10 Colorless oil,
Yield: 89%; 1H NMR (500 MHz, CDCl3): δH 4.75 (d, J =
6.5 Hz, 1H), 6.34 (dd, J = 15.5, 6.5 Hz, 1H), 6.78 (d, J =
15.5 Hz, 1H), 7.22–7.40 (m, 12H), 7.49–7.50 (m, 3H); 13C
NMR (125 MHz, CDCl3): δC 41.37, 85.55, 88.96, 123.60,
126.67, 127.24, 127.68, 127.89, 128.17, 128.40, 128.67, 128.86,
129.77, 130.60, 131.85; IR (cm−1, CHCl3): ν 3082, 3061, 3028,
2956, 2926, 2856, 1724, 1598, 1490, 1448, 1274, 1070, 964,
756 cm−1; GC-MS: m/z 294 (M)+.
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Acknowledgements
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3327.
We thank University of North Florida for support and Dr Nelson
Zhao of this department for NMR assistance.
This journal is © The Royal Society of Chemistry 2012
Org. Biomol. Chem., 2012, 10, 7347–7355 | 7355