Synthesis of allenes via gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds

Article abstract of DOI:10.1021/jo300147u

Functionalized allenes are efficiently synthesized in moderate to high yield from gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds. The user-friendly process could be conducted under mild reaction conditions with easily accessible starting materials.

Full text of DOI:10.1021/jo300147u

Note
pubs.acs.org/joc
Synthesis of Allenes via Gold-Catalyzed Intermolecular Reaction of
Propargylic Alcohols and Aromatic Compounds
Cheng-Fu Xu, Mei Xu, Liu-Qing Yang, and Chuan-Ying Li*
Department of Chemistry, Zhejiang Sci-Tech University, Xiasha West Higher Education District, Hangzhou 310018, China
S
* Supporting Information
ABSTRACT: Functionalized allenes are efficiently synthe-
sized in moderate to high yield from gold-catalyzed
intermolecular reaction of propargylic alcohols and aromatic
compounds. The user-friendly process could be conducted
under mild reaction conditions with easily accessible starting
materials.
llenes are versatile synthons in synthetic organic chemistry
because of their unique cumulene structure and axis-to-
moiety allows many further synthetic modifications; many
research works have been reported in this area.29−32
Considering the resonance between propargyl carbocation
and allene cation, we envisioned that by tuning the properties
of nucleophiles, C3 attack reaction may be realized and thus
allenes can be prepared in a simple manner. Here, we report an
intermolecular reaction of propargylic alcohol and aromatic
compounds leading to allenes.
Initially, m-xylene 2a was selected and reacted with
propargylic alcohol 1a in the presence of various gold catalysts
at room temperature. All of the gold catalysts we screened gave
some allene products in several hours (Table 1, entries 1−5),
and catalyst 6 proved to be the best (entry 5). Reaction
temperature, silver salts, and solvents were investigated next,
and the yield could be improved to 58% when the reaction
conducted in Cl2CHCHCl2 with 4 mol % of 6 and 8 mol % of
AgSbF6 (entry 8). Control experiments demonstrated that
AgSbF6 was necessary (entry 9). AgSbF6 and HSbF6 could also
catalyze the reaction but with an enormously diminished rate
(entries 10 and 11). When the reaction conducted in an open
flask, a slightly higher yield was obtained (entry 12). Molecular
sieves were necessary for high yield (entry 13). Finally, when 5
equiv of 2a was used, allene products could be obtained in 47%
yield (entry 14).
Using the conditions from entry 12 of Table 1 and
mesitylene as the nucleophile, we were pleased to find that
functionalized allenes could be regioselectively synthesized in
moderate to high yields (Table 2). Propargyl alcohols bearing
electron-rich (entries 2 and 3) and electron-deficient (entries
4−7) aromatic rings were effective, although a slightly lower
yield was observed when the substituent was p-MeOC6H4
(entry 3). Notably, p-BrC6H4 and p-IC6H4 were well tolerated
in this reaction, which provides a handle for further
functionalization (entries 6 and 7). Trisubstituted allenes
could be obtained in high yield (entries 7−9) when tertiary
propargylic alcohols were used. Additionally, internal alkynyl
A
center chirality transfer ability.1,2 Additionally, allenes are
important subunits in a variety of natural products and
pharmaceutically related compounds.3 As a result, efficient
and simple approaches for synthesizing allenes are hot topics of
organic chemists.4,5 Among all the methods developed, the SN2′
displacement of propargylic compounds with organometallic
reagents is the most commonly used one.6 Moreover, methods
based on the construction of 1,2-diene skeleton have also been
developed.7−12 Despite this, considering the importance of
allenes, new efficient and versatile catalytic processes to access
allenes are still of great interest.
In the past decade, gold salts have emerged as powerful
catalysts in the carbon−carbon multibonds related reac-
tions.13−15 Because of the good functional group tolerance
and low air and moisture sensitivity, gold catalysts have been
used to construct some complicated compounds. Allenes are
normally used as substrates or intermediates in gold-catalyzed
cascade reactions.16 On the other hand, synthesis of allenes in
the presence of gold catalysts has also been reported in recent
years.9,17−26 However, most of these reactions are intra-
molecular versions, and very bulky phosphine or NHC ligands
were used to achieve high chemoselectivity. In 2005, Campagne
reported an SN1 reaction of propargylic alcohol (Scheme 1)27,28
where various C-, O-, and S-nucleophiles were used. Since only
racemic product could be obtained from enantiomerically
enriched propargylic alcohol, the author proposed an SN1
mechanism. Direct substitution of propargylic alcohols is
attractive because water is the only byproduct and the alkyne
Scheme 1. Initial Hypothesis
Received: January 24, 2012
Published: February 22, 2012
© 2012 American Chemical Society
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The Journal of Organic Chemistry
Note
a
Table 1. Optimization of Reaction Conditions
b
c
entry
catalyst (4 mol %)
solvent
temp (°C)
time (h)
yield (%) (3aa:3aa′:4a + 4a′)
1
AuCl
ClCH2CH2Cl
ClCH2CH2Cl
ClCH2CH2Cl
ClCH2CH2Cl
ClCH2CH2Cl
ClCH2CH2Cl
ClCH2CH2Cl
Cl2CHCHCl2
Cl2CHCHCl2
Cl2CHCHCl2
Cl2CHCHCl2
Cl2CHCHCl2
Cl2CHCHCl2
Cl2CHCHCl2
rt
rt
4.0
4.0
5.0
5.0
4.5
1.0
1.1
1.5
24
10
2
AuCl3
15
3
Ph3PAuCl/AgSbF6
5/AgSbF6
rt
36 (1.0:0.4:0.5)
20 (1.0:0.5:0.8)
46 (1.0:0.25:0.5)
52 (1.0:0.3:0.56)
25 (1.0:0.62:0.5)
58 (1.0:0.32:0.3)
no reaction
4
rt
d
5
6/AgSbF6
rt
d
6
6/AgSbF6
50
50
50
50
50
50
50
50
50
d
7
6/AgOTf
d
8
6/AgSbF6
9
6
d
10
11
AgSbF6
24
29 (1.0:0.4:0.51)
22 (0.78:1.0:0.36)
60 (1.0:0.31:0.3)
50 (1.0:0.52:0.3)
47 (1.0:0.4:0.5)
h
HSbF6
24
e
d
12
6/AgSbF6
1.1
2.0
2.5
e
,
,
f
d
13
14
6/AgSbF6
e
g
d
6/AgSbF6
a
0.2 mmol of propargylic alcohol and 2.0 mmol of m-xylene. The reactions were carried out under an atmosphere of nitrogen in 2 mL of dry solvent.
b
c
d
e
Yield of 3aa and 3aa′. Molar ratio of products based on 1H NMR analysis of the crude reaction mixture. 8 mol % of AgSbF6. The reaction was
f
g
h
conducted in the air with solvent of technical grade. No molecular sieves. 0.2 mmol of propargylic alcohol and 1.0 mmol of m-xylene. 8 mol % of
HSbF6.
a
Table 2. Reaction Scope
b
c
entry
substrate (R1, R2, R3)
time (min)
product
yield (%) (3:4)
1
2
1b (Ph, H, H)
20
15
10
20
30
60
15
10
5
3bb
3cb
3db
3eb
3ab
3fb
69 (1.0:0.23)
75 (1.0:0.25)
49 (1.0:0.23)
69 (1.0:0.14)
73 (1.0:0.26)
51 (1.0:0.30)
82 (1.0:0)
1c (p-CH3C6H4, H, H)
1d (p-CH3OC6H4, H, H)
1e (p-FC6H4, H, H)
1a (p-ClC6H4, H, H)
1f (p-BrC6H4, H, H)
1g (p-IC6H4, CH3, H)
1h (Ph, CH3, H)
3
4
5
6
7
3gb
3hb
3ib
8
90 (1.0:0)
9
1i (Ph, Ph, H)
90 (1.0:0)
10
11
12
13
14
15
1j (Ph, H, Ph)
17
20
12
25
600
600
3jb
87 (1.0:0.08)
87 (1.0:0.09)
82 (1.0:0)
1k (Ph, H, n-C8H17)
1l (Ph, H, cyclopropyl)
1m (Ph, CH3, cyclopropyl)
1n (PhCH2, H, H)
1o (n-C7H15, H, H)
3kb
3 lb
3mb
3nb
3ob
73 (1.0:0)
d
NR
d
NR
a
0.2 mmol of propargylic alcohol and 2 mmol of mesitylene. The reactions were carried out in an open flask in 2 mL of Cl2CHCHCl2 of technical
b
c
d
1
grade. Yield of allene product. Molar ratio of products based on H NMR analysis of the crude reaction mixture. No reaction.
substrates also worked well (entries 10−13), both aryl group
and alkyl group were tolerated and the regioselectivities were
better than terminal propargylic alcohols. Tetrasubstituted
allene could also be easily obtained (entry 13). Unfortunately,
the reaction did not work when neither R1 nor R2 was an
aromatic ring (entries 14 and 15).
compounds were investigated. p-Xylene, m-xylene, 1,2,4,5-
tetramethylbenzene, and pentamethylbenzene are all effective
nucleophiles for this reaction (Table 3, entries 1−5). When m-
xylene was used, an inseparable mixture with a p-, o- ratio of
1.0:0.53 could be obtained (entry 1). Aromatic compounds
with a substituent other than a methyl group were also
investigated. Ketone and cyano groups are well tolerated in the
reaction (entries 6−8), and functionalized allenes could be
To further demonstrate the effectiveness of this gold-
catalyzed allene synthesis procedure, a variety of aromatic
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Note
a
Table 3. Substrate Scope
a
0.2 mmol of propargylic alcohol and 2 mmol of NuH. The reactions were carried out in an open flask in 2 mL of Cl2CHCHCl2 of technical grade.
b
c
d
Yield of allene product. Molar ratio of allene and alkyne products based on 1H NMR analysis of the crude reaction mixture. Para-attack product
e
f
3:ortho-attack product 3′. Toluene as solvent. No allene product, ratio of alkyne isomers.
Scheme 2. Reaction Scope
obtained in moderate yield. To gain more information about
the relationship of regioselectivity and arene nucleophiles,
toluene, anisole, and 1,3-dimethoxybenzene were tested in this
reaction. When 10 equiv of toluene was used, only very poor
yield was achieved. However, when toluene was used as solvent,
allene products 3bi and 3bi′ could be obtained in 51% yield
(entry 9). When anisole or 1,3-dimethoxybenzene were used as
nucleophile, only alkyne products could be isolated (entries 10
and 11).
Impressively, when compound 1p was prepared, which has
two carbon carbon triple bonds, and employed for the synthesis
of allene (Scheme 2, eq 1), 3pb could be obtained smoothly in
66% yield in only 20 min. Additionally, the reaction of substrate
1q led to the formation of bisallene 3qb in 55 min (Scheme 2,
eq 2).
to the substitution reaction (Table 2, entries 14 and 15), which
indicated a similar carbocation mechanism. Further experi-
ments showed that the conversion of substrates with p-
NO2C6H4 or p-CF3C6H4 substituents at the propargylic
position was very low (Scheme 3). Additionally, 3bb was
obtained with only 6% ee when enantiomerically enriched
propargylic alcohol 1b and mesitylene were used. All these
results suggest an SN1-type reaction mechanism (Scheme 3).
The next issue needs to be addressed is the different
regioselectivity. On the basis of the data we obtained, a simple
steric effect is not a key factor for the regioselectivity (Table 2,
entries 1−9 vs 10−13). We proposed loose ion pair was formed
as a key intermediate in the reaction (Scheme 3), and the
interaction between nucleophile and gold catalyst resulted in
different products. Thus, coordination of cationic [AuL]2+ to
the triple bond and OH group leads to intermediate I, which
eliminates [HOAuL]+ to afford loose ion pair II. When
nucleophiles bearing OMe group were used, [HOAuL]+
coordinated to the oxygen atom, and then the nucleophile
would attack the propargylic position, which led to product 4,
water, and regenerated [AuL]2+. On the contrary, when a
nucleophile such as mesitylene was used, no coordination could
be expected, and then mesitylene attacked the C3 position
because of steric bias, which led to allene 3.
In Campagne’s report,27,28 the author observed the lack of
reactivity when the aryl ring at the C1 or C3 position (Scheme
1) was substituted by strong electron-withdrawing groups or
when the propargylic position is only substituted by one alkyl
group. In light of these facts, the author proposed an SN1
carbocation mechanism with gold catalyst acting as a Lewis
acid. This mechanism was further confirmed when enantiomeri-
cally enriched substrate led to racemic product. Under our
reaction conditions, only benzylic propargylic alcohols gave rise
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Note
(d, J = 8.6 Hz, 2H), 5.41 (d, J = 2.1 Hz, 1H), 3.81 (s, 3H), 2.65 (d, J =
2.1 Hz, 1H), 2.31 (s, 1H).
Scheme 3. Proposed Reaction Mechanism
1-(4-Fluorophenyl)prop-2-yn-1-ol (1e):.35 yellow oil (1.2 g, 78%);
1H NMR (400 MHz, CDCl3) δ: 7.53 (dd, J = 8.2, 5.4 Hz, 2H), 7.07 (t,
J = 8.6 Hz, 2H), 5.45 (dd, J = 5.7, 2.1 Hz, 1H), 2.68 (d, J = 2.1 Hz,
1H), 2.27 (d, J = 5.7 Hz, 1H).
1-(4-Bromophenyl)prop-2-yn-1-ol (1f):.36 pale yellow solid (1.8 g,
85%); 1H NMR (400 MHz, CDCl3) δ: 7.52 (d, J = 8.4 Hz, 2H), 7.43
(d, J = 8.4 Hz, 2H), 5.43 (dd, J = 5.9, 1.7 Hz, 1H), 2.68 (d, J = 1.7 Hz,
1H), 2.23 (d, J = 5.9 Hz, 1H).
2-(4-Iodophenyl)but-3-yn-2-ol (1g): orange solid (1.8 g, 65%); mp
67−69 °C; IR (film) 3391, 3293, 2985, 2928, 2115, 1584, 1482 cm−1;
1H NMR (400 MHz, CDCl3) δ 7.69 (d, J = 8.6 Hz, 2H), 7.40 (d, J =
8.6 Hz, 2H), 2.68 (s, 1H), 2.37 (s, 1H), 1.75 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 144.8, 137.4, 127.0, 93.5, 86.6, 73.4, 69.5, 33.1;
HRMS (EI) calcd for C10H9IO M+ 271.9698, found 271.9691.
2-Phenylbut-3-yn-2-ol (1h):.37 pale yellow solid (1.1 g, 75%); H
1
NMR (400 MHz, CDCl3) δ: 7.67 (d, J = 8.2 Hz, 2H), 7.37 (t, J = 7.4
Hz, 2H), 7.30 (t, J = 7.0 Hz, 1H), 2.67 (s, 1H), 2.33 (s, 1H), 1.79 (s,
3H).
1,1-Diphenylprop-2-yn-1-ol (1i):.38 colorless solid (1.8 g, 88%); 1H
NMR (400 MHz, CDCl3) δ: 7.61 (d, J = 7.2 Hz, 4H), 7.34 (t, J = 7.3
Hz, 4H), 7.30−7.24 (m, 2H), 2.88 (s, 1H), 2.78 (s, 1H).
1,3-Diphenylprop-2-yn-1-ol (1j):.39 colorless solid (1.8 g, 85%); 1H
NMR (400 MHz, CDCl3) δ: 7.63 (d, J = 7.3 Hz, 2H), 7.50−7.42 (m,
2H), 7.42 (t, J = 7.3 Hz, 2H), 7.40−7.27 (m, 4H), 5.70 (d, J = 6.2 Hz,
1H), 2.31 (d, J = 6.2 Hz, 1H).
1-Phenylundec-2-yn-1-ol (1k):.40 pale yellow oil (2.3 g, 93%); H
1
NMR (400 MHz, CDCl3) δ 7.55 (d, J = 7.0 Hz, 2H), 7.41−7.35 (m,
2H), 7.35−7.29 (m, 1H), 5.45 (d, J = 6.1 Hz, 1H), 2.27 (dt, J = 7.1, 2.0
Hz, 2H), 2.11 (d, J = 6.1 Hz, 1H), 1.57−1.50 (m, 2H), 1.45−1.34 (m,
2H), 1.34−1.20 (m, 8H), 0.88 (t, J = 6.8 Hz, 3H).
In summary, we have presented the first example that allenes
can be synthesized via an intermolecular reaction of benzylic
propargylic alcohols and alkyl-substituted aromatic compounds,
which catalyzed by a commercially available gold catalyst. Di-,
tri-, and tetrasubstituted allenes could be obtained very easily.
Among the reasons for its appeal are easily accessible reagents,
a user-friendly procedure, mild reaction conditions, short
reaction time, and water as the only byproduct.
3-Cyclopropyl-1-phenylprop-2-yn-1-ol (1l):.41 colorless oil (1.7 g,
1
99%); H NMR (400 MHz, CDCl3) δ:7.50 (d, J = 7.5 Hz, 2H), 7.35
(t, J = 7.5 Hz, 2H), 7.30 (t, J = 7.5 Hz, 1H), 5.39 (d, J = 5.6 Hz, 1H),
2.30 (t, J = 6.2 Hz, 1H), 1.35−1.24 (m, 1H), 0.82−0.74 (m, 2H),
0.74−0.66 (m, 2H).
4-Cyclopropyl-2-phenylbut-3-yn-2-ol (1m):.42 pale yellow oil (1.5
g, 80%); 1H NMR (400 MHz, CDCl3) δ 7.67−7.60 (m, 2H), 7.35 (t, J
= 7.4 Hz, 2H), 7.29 (t, J = 7.4 Hz,1H), 2.25 (s, 1H), 1.73 (s, 3H),
1.35−1.29 (m, 1H), 0.85−0.77 (m, 2H), 0.75−0.70 (m, 2H).
1-Phenylbut-3-yn-2-ol (1n):.43 pale yellow oil (1.0 g, 70%); 1H
NMR (400 MHz, CDCl3) δ 7.38−7.23 (m, 5H), 4.61−4.59 (m, 1H),
3.07−2.97 (m, 2H), 2.49 (d, J = 2.0 Hz, 1H), 1.93 (d, J = 5.9 Hz, 1H).
EXPERIMENTAL SECTION
■
General Procedure for Synthesis of Propargylic Alcohol. To
a solution of trimethylsilylacetylene (1.1 g, 11 mmol) in THF (10 mL)
at −70 °C was added n-BuLi (4.4 mL, 11 mmol, 2.5 M in hexane)
dropwise under N2 atmosphere. The mixture was stirred for 1 h at −70
°C, the corresponding aldehyde (10 mmol) was added, and the
reaction was stirred for an additional 30 min at −70 °C and warmed to
room temperature over 30 min. The mixture was quenched with
saturated NH4Cl solution and extracted with diethyl ether. The
organic layers were combined, washed with brine, and dried over
MgSO4, and the solvent was evaporated under reduced pressure.
K2CO3 (4.1 g, 30 mmol) was added to the crude mixture in MeOH
(10 mL), and stirring was continued at room temperature for 2 h. The
mixture was filtered through a short plug of silica gel. After evaporation
of the solvent, the residue was purified by column chromatography on
silica gel to afford the corresponding propargylic alcohol.
Dec-1-yn-3-ol (1o):.34 clear oil (1.5 g, 95%); H NMR (400 MHz,
1
CDCl3) δ 4.30 (q, J = 5.2 Hz, 1H), 2.39 (d, J = 1.9 Hz, 1H), 1.81−1.60
(m, 3H), 1.56−1.09 (m, 10H), 0.81 (t, J = 6.2 Hz, 3H).
2-(4-(Phenylethynyl)phenyl)but-3-yn-2-ol (1p): yellow solid (1.5 g,
62%); mp 78−80 °C; IR (film) 3399, 3288, 2984, 2930, 2213, 2104,
1593, 1505 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.64 (d, J = 8.1 Hz,
2H), 7.53 (d, J = 7.1 Hz, 4H), 7.34 (s, 3H), 2.69 (s, 1H), 2.46 (s, 1H),
1.78 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 145.0, 131.61, 131.58,
128.33, 128.30, 125.0, 123.2, 122.8, 89.7, 89.0, 86.8, 73.4, 69.7, 33.0;
HRMS (EI) calcd for C18H14O M+ 246.1045, found 246.1042.
1,1′-(1,4-Phenylene)diprop-2-yn-1-ol (1q):.44 yellow solid (1.2 g,
67%); 1H NMR (400 MHz, CDCl3) δ 7.59 (s, 4H), 5.49 (s, 2H), 2.68
(s, 2H), 2.21 (br s, 2H).
1-(4-Chlorophenyl)prop-2-yn-1-ol (1a):.33 yellow oil (1.6 g, 93%);
1H NMR (400 MHz, CDCl3) δ: 7.49 (d, J = 7.9 Hz, 2H), 7.36 (d, J =
7.9 Hz, 2H), 5.45 (d, J = 5.1 Hz, 1H), 2.68 (s, 1H), 2.30 (t, J = 5.1 Hz,
1H).
General Procedure for Synthesis of 4-Aryl-2-butaone.
Anhydrous ethanol (8 mL) was placed in a three-necked flask (50
mL) fitted with reflux condenser. Small pieces of sodium (0.3 g, 12
mmol) were added and dissolved to form sodium ethoxide. Ethyl
acetoacetate (1.6 g, 12 mmol) was added and the mixture stirred for 2
h. After the addition of benzyl chloride (1.3 g, 10 mmol), the reaction
mixture was heated under reflux on oil bath for 4−5 h and kept at
room temperature for 4 h. Ethanol was distilled off under reduced
pressure, and the reaction mixture was quenched with saturated
aqueous ammonium chloride (8 mL) and extracted with ether. The
extract was dried over Na2SO4, and the solvent was removed under
reduced pressure. The residue was purified by flash chromatography to
afford ethyl α-benzylacetoacetate.
1-Phenylprop-2-yn-1-ol (1b):.34 yellow oil (1.2 g, 89%); H NMR
1
(400 MHz, CDCl3) δ: 7.54−7.47 (m, 2H), 7.39−7.27 (m, 3H), 5.39
(dd, J = 6.0, 2.2 Hz, 1H), 2.91 (br s, 1H), 2.62 (d, J = 2.2 Hz, 1H).
1-p-Tolylprop-2-yn-1-ol (1c):.35 yellow oil (1.2 g, 80%); H NMR
1
(400 MHz, CDCl3) δ: 7.44 (d, J = 7.8 Hz, 2H), 7.20 (d, J = 7.8 Hz,
2H), 5.43 (d, J = 6.2 Hz, 1H), 2.65 (s, 1H), 2.36 (s, 3H), 2.15 (d, J =
6.2 Hz, 1H).
1-(4-Methoxyphenyl)prop-2-yn-1-ol (1d):.35 yellow oil (1.4 g,
86%); 1H NMR (400 MHz, CDCl3) δ: 7.47 (d, J = 8.6 Hz, 2H), 6.90
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Note
NaOH solution (40%, 3.9 g, 39 mmol) was added to the flask
charged with ethyl α-benzylacetoacetate and the mixture stirred for
several minutes. Water was added to the mixture to dissolve the solid.
The solution was heated to 70 °C and stirred for about 2.5 h. The
mixture was cooled to room temperature and acidified with
concentrated hydrochloric acid. The mixture was reheated to 70 °C
and stirred for another 3 h. The obtained mixture was extracted with
ether and wash with brine. The organic solution was dried and filtered.
Solvent was removed under reduced pressure, and the residue was
purified by flash chromatography to afford product.
10.00H), 7.28−7.20 (m, 5.29H), 7.18−7.10 (m, 5.72H), 6.78 (d, J =
6.6 Hz, 1.1H), 6.56 (d, J = 9.2 Hz, 3.01H), 2.42 (s, 3H), 2.33 (s,
3.18H).
1,3,5-Trimethyl-2-(3-p-tolylpropa-1,2-dienyl)benzene (3cb): pale
yellow oil (37.3 mg, 75%); IR (film) 3011, 2964, 2918, 2857, 1932,
1610, 1511, 1376, 832 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.23 (d, J
= 7.6 Hz, 2H), 7.11 (d, J = 7.6 Hz, 2H), 6.85 (s, 2H), 6.71 (d, J = 6.8
Hz, 1H), 6.32 (d, J = 6.8 Hz, 1H), 2.35 (s, 6H), 2.32 (s, 3H), 2.25 (s,
3H); 13C NMR (100 MHz, CDCl3) δ 207.8, 136.63, 136.59, 136.4,
131.5, 129.3, 129.1, 128.1, 126.9, 95.2, 93.7, 21.3, 21.2, 20.9; HRMS
(EI) calcd for C19H20 M+ 248.1565, found 248.1561.
4-Mesitylbutan-2-one (2f):.45 white solid (1.3 g, 70%); H NMR
1
(400 MHz, CDCl3) δ 6.83 (s, 2H), 2.86 (t, J = 8.0 Hz, 2H), 2.56 (t, J =
8.0 Hz, 2H), 2.26 (s, 6H), 2.24 (s, 3H), 2.17 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 208.3, 135.9, 135.4, 134.4, 129.0, 42.8, 29.8, 23.3,
20.7, 19.6.
2-(3-(4-Methoxyphenyl)propa-1,2-dienyl)-1,3,5-trimethylbenzene
(3db): pale yellow oil (25.9 mg, 49%); IR (film) 2956, 2922, 2853,
1
1932, 1607, 1509, 1376, 834 cm−1; H NMR (400 MHz, CDCl3) δ
7.32 (d, J = 8.7 Hz, 2H), 6.94−6.89 (m, 4H), 6.76 (d, J = 6.8 Hz, 1H),
6.36 (d, J = 6.8 Hz, 1H), 3.85 (s, 3H), 2.41 (s, 6H), 2.31 (s, 3H); 13C
NMR (100 MHz, CDCl3) δ 207.6, 158.7, 136.6, 136.4, 129.1, 128.2,
128.0, 126.8, 114.1, 94.8, 93.7, 55.3, 21.3, 20.9; HRMS (EI) calcd for
C19H20O M+ 264.1514, found 264.1513.
4, 4′-(1,4-Phenylene)dibutan-2-one (2h):.46 white solid (0.9 g,
1
40%); H NMR (400 MHz, CDCl3) δ: 7.09 (s, 4H), 2.86 (t, J = 7.6
Hz, 4H), 2.74 (t, J = 7.6 Hz, 4H), 2.13 (s, 6H).
General Procedure for Synthesis of Allenes. Cl2CHCHCl2
(0.5 mL) was added to reaction flask charged with dichloro(2-
pyridinecarboxylato)gold (4.2 mg, 4 mmol %), AgSbF6 (5.4 mg, 8
mmol %), and 4 Å molecular sieves (17 mg). The reaction mixture was
heated to 50 °C and stirred for 5 min. After 2 mmol of mesitylene was
added, a solution of propargylic alcohols (0.2 mmol) in Cl2CHCHCl2
(1.5 mL) was added dropwise in 5 min. The reaction was stirred until
TLC analysis showed that propargylic alcohol was completely
consumed. The reaction mixture was cooled to room temperature
and filtered through a short plug of silica gel. The solution of mixture
was concentrated and then purified by flash chromatography to give
the product.
2-(3-(4-Fluorophenyl)propa-1,2-dienyl)-1,3,5-trimethylbenzene
(3eb): pale yellow oil (34.8 mg, 69%); IR (film) 2969, 2916, 2857,
1
1933, 1603, 1498, 1376, 837 cm−1; H NMR (400 MHz, CDCl3) δ
7.30 (dd, J = 8.2, 5.7 Hz, 2H), 7.00 (t, J = 8.6 Hz, 2H), 6.87 (s, 2H),
6.73 (d, J = 6.8 Hz, 1H), 6.32 (d, J = 6.8 Hz, 1H), 2.35 (s, 6H), 2.27
(s, 3H); 13C NMR (100 MHz, CDCl3) δ 207.8, 163.2, 160.7, 136.7,
130.53, 130.50, 129.2, 128.4, 128.3, 127.9, 115.7, 115.5, 94.5, 94.0,
21.3, 20.9; HRMS (EI) calcd for C18H17F M+ 252.1314, found
252.1313.
1-(3-(4-Bromophenyl)propa-1,2-dienyl)-2,4-dimethylbenzene
(3fa) and 2-(3-(4-Bromophenyl)propa-1,2-dienyl)-1,3-dimethylben-
zene (3fa′). The crude product was purified by flash chromatography
(petroleum ether) to give the product in a ratio of approximately
1.0:0.53 according to 1H NMR: pale yellow oil, 31.7 mg, 53%;
IR(film) 3015, 2976, 2919, 2851, 1933, 1621, 1496, 1378, 833 cm−1;
1H NMR (400 MHz, CDCl3) δ 7.44−7.38 (m, 3.06H), 7.23 (s,
1-(3-(4-Chlorophenyl)propa-1,2-dienyl)-2,4-dimethylbenzene
(3aa) and 2-(3-(4-Chlorophenyl)propa-1,2-dienyl)-1,3-dimethylben-
zene (3aa′). The crude product was purified by flash chromatography
(petroleum ether) to give the product with ratio about 1.0:0.31
1
according to H NMR (colorless oil, 30.6 mg, 60%): IR (film) 3013,
2920, 2851, 1932, 1499, 1378, 835 cm−1; 1H NMR (400 MHz,
CDCl3) δ 7.30−7.22 (m, 5.6H), 7.07−6.91 (m, 3.5H), 6.75 (d, J = 6.6
Hz, 1.31H), 6.47 (d, J = 6.6 Hz, 1H of 3aa), 6.31 (d, J = 6.6 Hz, 0.31H
of 3aa′), 2.37 (s, 1.86H of 3aa′), 2.35 (s, 3H of 3aa), 2.29 (s, 3H of
3aa); 13C NMR (100 MHz, CDCl3) δ 208.3, 208.1, 137.2, 136.7,
135.3, 132.9, 132.67, 132.65, 132.56, 131.5, 130.7, 128.83, 128.78,
128.5, 128.4, 128.1, 128.0, 127.6, 127.0, 96.6, 96.1, 94.6, 94.2, 21.4,
21.0, 19.9; HRMS (EI) calcd for C17H15Cl M+ 254.0862, found
254.0868.
1.06H), 7.22−7.14 (m, 3H), 7.04 (s, 1.53H), 6.98 (s, 1H), 6.94 (d, J =
7.8 Hz, 1.06H), 6.74 (d, J = 6.6 Hz, 1.53H), 6.46 (d, J = 6.6 Hz, 1H of
3fa), 6.29 (d, J = 6.8 Hz, 0.53H of 3fa′), 2.37 (s, 3.18H of 3fa′), 2.35
(s, 3H of 3fa), 2.29 (s, 3H of 3fa); 13C NMR (100 MHz, CDCl3) δ
208.3, 208.1, 137.2, 136.7, 135.3, 133.4, 133.1, 131.8, 131.7, 131.5,
130.6, 128.5, 128.4, 127.6, 127.0, 120.8, 120.6, 96.7, 96.2, 94.6, 94.2,
21.4, 21.1, 19.9; HRMS (EI) calcd for C17H15Br M+ 298.0357, found
298.0359.
2-(3-(4-Bromophenyl)propa-1,2-dienyl)-1,3,5-trimethylbenzene
(3fb): pale yellow oil (31.9 mg, 51%); IR (film) 2970, 2917, 2854,
2-(3-(4-Chlorophenyl)propa-1,2-dienyl)-1,3,5-trimethylbenzene
(3ab): pale yellow oil (39.2 mg, 73%); IR (film) 2980, 2926, 2857,
1938, 1599, 1375, 833 cm−1; 1H NMR (400 MHz, CDCl3) δ: 7.25 (s,
4H), 6.86 (s, 2H), 6.74 (d, J = 6.8 Hz, 1H), 6.30 (d, J = 6.8 Hz, 1H),
2.34 (s, 6H), 2.26 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 208.1,
136.7, 136.6, 133.1, 132.4, 129.2, 128.7, 128.1, 127.6, 94.5, 94.1, 21.3,
20.9; HRMS (EI) calcd for C18H17Cl M+ 268.1019, found 268.1013.
2-(3-(4-Chlorophenyl)propa-1,2-dienyl)-1,4-dimethylbenzene
(3ac): pale yellow oil (33.1 mg, 65%); IR (film) 3023, 2921, 2856,
1933, 1592, 1494, 812 cm−1; 1H NMR (400 MHz, CDCl3) δ: 7.28 (s,
4H), 7.16 (s, 1H), 7.06 (d, J = 7.6 Hz, 1H), 6.96 (d, J = 7.6 Hz, 1H),
6.76 (d, J = 6.6 Hz,1H), 6.50 (d, J = 6.6 Hz, 1H), 2.36 (s, 3H), 2.27 (s,
3H); 13C NMR (100 MHz, CDCl3) δ 208.4, 135.7, 132.7, 132.5,
132.4, 131.2, 130.6, 128.9, 128.3, 128.1, 128.0, 96.6, 96.3, 20.9, 19.5;
HRMS (EI) calcd for C17H15Cl M+ 254.0862, found 254.0859.
1,3,5-Trimethyl-2-(3-phenylpropa-1,2-dienyl)benzene (3bb): pale
yellow oil (32.3 mg, 69%); IR (film) 3028, 2968, 2916, 2857, 1934,
1600, 1495, 1376 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.26−7.37 (m,
4H), 7.20 (t, J = 7.0 Hz, 1H), 6.87 (s, 2H), 6.74 (d, J = 6.8 Hz, 1H),
6.35 (d, J = 6.8 Hz, 1H), 2.36 (s, 6H), 2.27 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 208.0, 136.6, 136.5, 134.5, 129.2, 128.6, 127.9, 127.0,
126.9, 95.4, 93.7, 21.3, 20.9; HRMS (EI) calcd for C18H18 M+
234.1409, found 234.1411.
1
1933, 1610, 1496, 1377, 831 cm−1; H NMR (400 MHz, CDCl3) δ
7.42 (d, J = 8.3 Hz, 2H), 7.20 (d, J = 8.3 Hz, 2H), 6.87 (s, 2H), 6.73
(d, J = 6.8 Hz, 1H), 6.29 (d, J = 6.8 Hz, 1H), 2.34 (s, 6H), 2.26 (s,
3H); 13C NMR (100 MHz, CDCl3) δ 208.1, 136.7, 136.6, 133.6,
131.7, 129.2, 128.4, 127.5, 120.5, 94.6, 94.1, 21.3, 20.9; HRMS (EI)
calcd for C18H17Br M+ 312.0514, found 312.0514.
2-(3-(4-Bromophenyl)propa-1,2-dienyl)-1,4-dimethylbenzene
(3fc): pale yellow oil (35.9 mg, 60%); IR (film) 3019, 2922, 2857,
1
1934, 1589, 1502, 1380, 814 cm−1; H NMR (400 MHz, CDCl3) δ
7.43 (d, J = 8.4 Hz, 2H), 7.21 (d, J = 8.4 Hz, 2H), 7.16 (s, 1H), 7.06
(d, J = 7.7 Hz, 1H), 6.95 (d, J = 7.7 Hz, 1H), 6.75 (d, J = 6.6 Hz, 1H),
6.48 (d, J = 6.6 Hz, 1H), 2.36 (s, 3H), 2.26 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 208.4, 135.7, 133.0, 132.4, 131.8, 131.1, 130.6, 128.4,
128.3, 128.0, 120.8, 96.7, 96.3, 20.9, 19.5; HRMS (EI) calcd for
C17H15Br M+ 298.0357, found 298.0360.
4-(3-(3-(4-Bromophenyl)propa-1, 2-dienyl)-2, 4, 6-
trimethylphenyl)butan-2-one (3ff): pale yellow oil (44.5 mg, 58%);
1
IR (film) 2970, 2920, 1940, 1694, 1486, 1360, 833 cm−1; H NMR
(400 MHz, CDCl3) δ 7.42 (d, J = 7.4 Hz, 2H), 7.19 (d, J = 7.4 Hz,
2H), 6.88 (s, 1H), 6.67 (d, J = 6.7 Hz, 1H), 6.26 (d, J = 6.7 Hz, 1H),
2.91 (t, J = 8.0 Hz, 2H), 2.55 (t, J = 8.0 Hz, 2H), 2.33 (s, 3H), 2.31 (s,
3H), 2.27 (s, 3H), 2.16 (s, 2H); 13C NMR (100 MHz, CDCl3) δ
208.1, 207.5, 135.6, 135.1, 134.5, 134.4, 133.3, 131.7, 130.3, 129.3,
128.5, 120.6, 94.7, 94.3, 43.0, 29.8, 23.9, 21.2, 19.9, 16.9; HRMS (EI)
calcd for C22H23BrO M+ 382.0932, found 382.0926.
1-Methyl-4-(3-phenylpropa-1,2-dienyl)benzene (3bi)47 and 1-
Methyl-2-(3-phenylpropa-1,2-dienyl)benzene (3bi′):.48 colorless oil
(21.0 mg, 51%); 1H NMR (400 MHz, CDCl3) δ 7.44−7.27 (m,
3014
dx.doi.org/10.1021/jo300147u | J. Org. Chem. 2012, 77, 3010−3016

The Journal of Organic Chemistry
Note
1
2-(3-(3-(4-Bromophenyl)propa-1, 2-die nyl)-2, 4, 6-
trimethylphenyl)acetonitrile (3fg): pale yellow oil (23.3 mg, 33%); IR
(film) 2922, 2853, 2247, 1940, 1587, 1497, 1378, 833 cm−1; 1H NMR
(400 MHz, CDCl3) δ 7.43 (d, J = 8.4 Hz, 2H), 7.19 (d, J = 8.4 Hz,
2H), 6.95 (s, 1H), 6.66 (d, J = 6.8 Hz, 1H), 6.29 (d, J = 6.8 Hz, 1H),
3.64 (s, 2H), 2.43 (s, 3H), 2.35 (s, 3H), 2.33 (s, 3H); 13C NMR (100
MHz, CDCl3) δ: 207.5, 136.7, 135.4, 135.1, 132.9, 131.7, 130.6, 130.0,
128.5, 125.7, 120.8, 117.4, 94.6, 94.3, 21.3, 20.1, 18.2, 17.4; HRMS
(EI) calcd for C20H18BrN M+ 351.0623, found 351.0618.
1946, 1610, 1599, 1496, 1458, 816, 745, 693 cm−1; H NMR (400
MHz, CDCl3) δ 7.34−7.29 (m, 2H), 7.26 (t, J = 7.6 Hz, 2H), 7.14 (t, J
= 7.6 Hz, 1H), 6.86 (s, 2H), 6.18 (t, J = 3.5 Hz, 1H), 2.35 (s, 6H),
2.31−2.26 (m, 1H), 2.24 (s, 3H), 2.22−2.14 (m, 1H), 1.62−1.54 (m,
2H), 1.41−1.34 (m, 2H), 1.28−1.20 (m, 8H), 0.85 (t, J = 6.8 Hz, 3H);
13C NMR (100 MHz, CDCl3) δ 202.6, 136.4, 135.5, 134.7, 128.6,
128.4, 126.9, 126.6, 107.9, 95.0, 33.8, 31.9, 29.7, 29.6, 29.4, 27.8, 22.7,
21.0, 20.4, 14.2; HRMS (EI) calcd for C26H34 M+ 346.2661, found
346.2667.
4,4′-(2-(3-(4-Bromophenyl)propa-1,2-dienyl)-1,4-phenylene)-
2-(1-Cyclopropyl-3-phenylpropa-1,2-dienyl)-1,3,5-trimethylben-
dibutan-2-one (3fh): pale yellow oil (48.4 mg, 59%); IR (film) 3004,
zene (3lb): pale yellow oil (44.9 mg, 82%); IR (film) 3082, 3005,
1
2924, 2848, 1935, 1707, 1609, 1486, 1363, 834 cm−1; H NMR (400
2917, 2856, 1942, 1610, 1594, 1495, 1457, 816, 746, 693 cm−1; H
1
MHz, CDCl3) δ 7.44 (d, J = 8.4 Hz, 2H), 7.21 (d, J = 8.4 Hz, 2H),
7.16 (s, 1H), 7.09 (d, J = 7.8 Hz, 1H), 7.00 (d, J = 7.8 Hz, 1H), 6.75
(d, J = 6.6 Hz, 1H), 6.50 (d, J = 6.6 Hz, 1H), 3.06−2.89 (m, 2H),
2.85−2.78 (m, 2H), 2.74−2.67 (m, 4H), 2.11 (s, 3H), 2.08 (s, 3H);
13C NMR (100 MHz, CDCl3) δ 208.5, 207.7, 207.5, 139.5, 136.2,
132.7, 131.9, 130.9, 130.1, 128.4, 128.0, 127.8, 121.0, 96.9, 95.9, 45.0,
44.6, 30.0, 29.9, 29.1, 26.9; HRMS (EI) calcd for C23H23BrO2 M+
410.0881, found 410.0865.
NMR (400 MHz, CDCl3) δ 7.32−7.23 (m, 4H), 7.18−7.12 (m, 1H),
6.87 (s, 2H), 6.22 (s, 1H), 2.38 (s, 6H), 2.25 (s, 3H), 1.41−1.37 (m,
1H), 0.85−0.70 (m, 2H), 0.59−0.45 (m, 2H); 13C NMR (100 MHz,
CDCl3) δ 201.8, 136.7, 136.1, 135.3, 133.3, 128.6, 128.4, 126.9, 126.7,
100.3, 95.9, 21.0, 20.7, 13.4, 7.5, 7.4; HRMS (EI) calcd for C21H22 M+
274.1722, found 274.1718.
2-(1-Cyclopropyl-3-phenylbuta-1,2-dienyl)-1,3,5-trimethylben-
zene (3mb): colorless oil (42.0 mg, 73%); IR (film) 3081, 3000, 2972,
2946, 2917, 2857, 1941, 1610, 1958, 1493, 1443, 1373, 848, 760, 692
cm−1; 1H NMR (400 MHz, CDCl3) δ 7.43−7.37 (m, 2H), 7.29 (t, J =
7.7 Hz, 2H), 7.16 (t, J = 7.7 Hz, 1H), 6.87 (s, 2H), 2.38 (s, 6H), 2.25
(s, 3H), 2.10 (s, 3H), 1.39−1.35 (m, 1H), 0.81−0.71 (m, 2H), 0.58−
0.41(m, 2H); 13C NMR (100 MHz, CDCl3) δ 200.7, 138.0, 136.4,
136.2, 134.0, 128.3, 128.2, 126.4, 125.9, 108.1, 102.1, 21.0, 20.9, 17.0,
13.7, 7.6, 7.1; HRMS (EI) calcd for C22H24 M+ 288.1878, found
288.1874.
2-(3-(4-Iodophenyl)buta-1,2-dienyl)-1,3,5-trimethylbenzene
(3gb): pale yellow oil (61.3 mg, 82%); IR (film) 2944, 2917, 2854,
1
1935, 1610, 1489, 1375, 812 cm−1; H NMR (400 MHz, CDCl3) δ
7.62 (d, J = 8.4 Hz, 2H), 7.16 (d, J = 8.4 Hz, 2H), 6.87 (s, 2H), 6.64
(q, J = 3.1 Hz, 1H), 2.33 (s, 6H), 2.26 (s, 3H), 2.14 (d, J = 3.1 Hz,
3H); 13C NMR (100 MHz, CDCl3) δ 207.2, 137.3, 136.9, 136.42,
136.37, 129.2, 128.2, 127.7, 100.0, 92.3, 91.8, 21.3, 20.9, 17.0; HRMS
(EI) calcd for C19H19I M+ 374.0531, found 374.0529.
1,3,5-Trimethyl-2-(3-phenylbuta-1,2-dienyl)benzene (3hb): pale
1,3,5-Trimethyl-2-(3-(4-(phenylethynyl)phenyl)buta-1,2-dienyl)-
yellow oil (44.6 mg, 90%); IR (film) 2920, 2856, 1934, 1609, 1375,
benzene (3pb): pale yellow oil (45.9 mg, 66%); IR (film) 3032, 2968,
1
852 cm−1; H NMR (400 MHz, CDCl3) δ 7.43 (d, J = 7.7 Hz, 2H),
2857, 2214, 1934, 1595, 1507, 1374, 840 cm−1; H NMR (400 MHz,
1
7.30 (t, J = 7.7 Hz, 2H), 7.18 (t, J = 7.3 Hz, 1H), 6.85 (s, 2H), 6.63 (q,
J = 3.1 Hz, 1H), 2.34 (s, 6H), 2.25 (s, 3H), 2.18 (d, J = 3.1 Hz, 3H);
13C NMR (100 MHz, CDCl3) δ 207.3, 137.1, 136.4, 136.2, 129.2,
128.6, 128.3, 126.5, 125.9, 100.6, 91.9, 21.3, 20.9, 17.2; HRMS (EI)
calcd for C19H20 M+ 248.1565, found 248.1560.
CDCl3) δ 7.52 (d, J = 5.6 Hz, 2H), 7.47 (d, J = 8.1 Hz, 2H), 7.40 (d, J
= 8.1 Hz, 2H), 7.32 (d, J = 5.4 Hz, 3H), 6.86 (s, 2H), 6.67 (s, 1H),
2.34 (s, 6H), 2.26 (s, 3H), 2.17 (s, 3H); 13C NMR (100 MHz, CDCl3)
δ 207.8, 137.2, 136.5, 136.4, 131.6, 129.2, 128.3, 128.1, 125.8, 123.4,
121.2, 100.5, 92.2, 89.7, 89.6, 21.3, 20.9, 17.1; HRMS (EI) calcd for
C27H24 M+ 348.1878, found 348.1876.
1,4-Bis(3-mesitylpropa-1,2-dienyl)benzene (3qb): white solid
(43.7 mg, 56%); mp 59−61 °C; IR (film) 3011, 2967, 2917, 2854,
1932, 1610, 1508, 1497, 1376, 850 cm−1; 1H NMR (400 MHz,
CDCl3) δ 7.29 (s, 4H), 6.86 (s, 4H), 6.73 (d, J = 6.7 Hz, 2H), 6.33 (d,
J = 6.7 Hz, 2H), 2.35 (s, 12H), 2.25 (s, 6H); 13C NMR (100 MHz,
CDCl3) δ 208.3, 136.6, 136.5, 133.1, 129.2, 127.9, 127.2, 95.2, 93.8,
21.3, 20.9; HRMS (EI) calcd for C30H30 M+ 390.2348, found
390.2351.
1,2,4,5-Tetramethyl-3-(3-phenylbuta-1,2-dienyl)benzene (3hd):
pale yellow oil (41.9 mg, 80%); IR (film) 2921, 2862, 1940, 1597,
1
1493, 1463, 1380 cm−1; H NMR (400 MHz, CDCl3) δ 7.42 (d, J =
7.6 Hz, 2H), 7.30 (t, J = 7.6 Hz, 2H), 7.18 (t, J = 7.3 Hz, 1H), 6.89 (s,
1H), 6.57 (q, J = 3.1 Hz, 1H), 2.29 (s, 6H), 2.23 (s, 6H), 2.18 (d, J =
3.1 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 206.3, 137.1, 133.7,
132.6, 132.3, 130.3, 128.2, 126.5, 125.9, 100.1, 92.9, 20.4, 16.9, 16.6;
HRMS (EI) calcd for C20H22 M+ 262.1722, found 262.1716.
1,2,3,4,5-Pentamethyl-6-(3-phenylbuta-1,2-dienyl)benzene
(3he): pale yellow oil (45.8 mg, 83%); IR (film) 3032, 2982, 2922,
1943, 1597, 1493, 1378 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.41 (d,
J = 7.6 Hz, 2H), 7.29 (t, J = 7.6 Hz, 2H), 7.17 (t, J = 7.3 Hz, 1H), 6.56
(q, J = 3.1 Hz, 1H), 2.36 (s, 6H), 2.23 (s, 3H), 2.22 (s, 6H), 2.16 (d, J
= 3.1 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 206.0, 137.2, 133.7,
132.5, 131.9, 130.4, 128.2, 126.4, 125.9, 100.0, 93.5, 18.1, 16.8, 16.7,
16.5; HRMS (EI) calcd for C21H24 M+ 276.1878, found 276.1868.
2-(3,3-Diphenylpropa-1,2-dienyl)-1,3,5-trimethylbenzene (3ib):
pale yellow oil (55.8 mg, 90%); IR (film) 3022, 2916, 2856, 1931,
1597, 1490, 1376, 853 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.38 (d, J
= 7.2 Hz, 4H), 7.32 (t, J = 7.5 Hz, 4H), 7.25 (t, J = 7.1 Hz,2H), 6.90
(s, 1H), 6.85 (s, 2H), 2.28 (s, 6H), 2.25 (s, 3H); 13C NMR (100 MHz,
CDCl3) δ 208.6, 136.9, 136.8, 136.5, 129.2, 128.5, 128.4, 128.2, 127.1,
110.0, 93.0, 21.3, 20.9; HRMS (EI) calcd for C24H22 M+ 310.1722,
found 310.1727.
ASSOCIATED CONTENT
■
S
* Supporting Information
NMR spectra for propargylic alcohols and allenes. This material
is available free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
■
Corresponding Author
*Email: licy@zstu.edu.cn.
Notes
The authors declare no competing financial interest.
2-(1,3-Diphenylpropa-1,2-dienyl)-1,3,5-trimethylbenzene (3jb):
pale yellow oil (53.9 mg, 87%); IR (film) 3080, 3059, 3026, 2918,
1
2855, 1933, 1609, 1596, 1489, 1446, 1376, 850, 766, 694 cm−1; H
ACKNOWLEDGMENTS
■
NMR (400 MHz, CDCl3) δ 7.37 (d, J = 7.2 Hz, 2H), 7.33−7.16 (m,
8H), 6.94 (s, 2H), 6.58 (s, 1H), 2.31 (s, 3H), 2.25 (s, 6H); 13C NMR
(100 MHz, CDCl3) δ 206.0, 137.2, 137.0, 135.6, 134.2, 131.7, 128.8,
128.7, 128.5, 127.22, 127.20, 126.2, 109.5, 97.1, 21.1, 20.6; HRMS
(EI) calcd for C24H22 M+ 310.1722, found 310.1720.
This work was generously supported by the National Natural
Science Foundation of China (21002091), Zhejiang Qianjiang
Program (2011R10019), and Zhejiang Sci-Tech University
(11432732611043, 11110032251010). We also thank Professor
Hong-Chao Guo of China Agricultural University for donation
of optically active propargylic alcohols.
1,3,5-Trimethyl-2-(1-phenylundeca-1,2-dien-3-yl)benzene (3kb):
colorless oil (60.2 mg, 87%); IR (film) 3030, 2950, 2924, 2854,
3015
dx.doi.org/10.1021/jo300147u | J. Org. Chem. 2012, 77, 3010−3016

The Journal of Organic Chemistry
Note
(42) Lu, G.; Li, X.; Li, Y.-M.; Kwong, F. Y.; Chan, A. S. C. Adv. Synth.
Catal. 2006, 348, 1926.
(43) Kong, W.; Ma, S. Eur. J. Org. Chem. 2011, 2278.
(44) Chassaing, S.; Kueny-Stotz, M. Eur. J. Org. Chem. 2007, 2438.
(45) Sakai, M.; Miyaura, N. Organometallics 1997, 16, 4229.
(46) Condon, S.; Dupre, D. Eur. J. Org. Chem. 2002, 105.
́
(47) Lo, V. K.-Y.; Zhou, C.-Y.; Wong, M.-K.; Che, C.-M. Chem.
Commun. 2010, 46, 213.
REFERENCES
■
(1) For books, see: (a) Schuster, H. F.; Coppola, G. M. Allenes in
Organic Synthesis; Wiley: New York, 1984. (b) Modern Allene
Chemistry; Krause, N., Hashmi, A. S. K., Eds.; Wiley-VCH: Weinheim,
2004.
(2) For recent reviews, see: (a) Brasholz, M.; Reissig, H.-U.; Zimmer,
R. Acc. Chem. Res. 2009, 42, 45. (b) Ma, S. Acc. Chem. Res. 2009, 42,
1679.
(48) Yoshida, M. Tetrahedron 2007, 63, 6996.
(3) Hoffmann-Roder, A.; Krause, N. Angew. Chem., Int. Ed. 2004, 43,
̈
1196. Also see ref 1b.
(4) For books, see: Brandsma, L.; Verkruijsse, H. D. Synthesis of
Acetylenes, Allenes and Cumulenes; Elsevier: Amsterdam, 1981. Also see
ref 1b, Vol. 1.
(5) For recent reviews, see: Yu, S.; Ma, S. Chem. Commun. 2011, 47,
5384.
(6) Miura, T.; Shimada, M.; de Mendoza, P.; Deutsch, C.; Krause, N.;
Murakami, M. J. Org. Chem. 2009, 74, 6050.
(7) Crabbe,
Chem. Commun. 1979, 859.
́ ́
P.; Fillion, H.; Andre, D.; Luche, J.-L. J. Chem. Soc.,
(8) Kuang, J.; Ma, S. J. Am. Chem. Soc. 2010, 132, 1786.
(9) Zeng, X.; Frey, G. D.; Kousar, S.; Bertrand, G. Chem.Eur. J.
2009, 15, 3056.
(10) Xiao, Q.; Xia, Y.; Li, H.; Zhang, Y.; Wang, J. Angew. Chem., Int.
Ed. 2011, 50, 1114.
(11) Li, C.-Y.; Wang, X.-B.; Sun, X.-L.; Tang, Y.; Zheng, J.-C.; Xu, Z.-
H.; Zhou, Y.-G.; Dai, L.-X. J. Am. Chem. Soc. 2007, 129, 1494.
(12) Li, C.-Y.; Zhu, B.-H.; Ye, L.-W.; Jing, Q.; Sun, X.-L.; Tang, Y.;
Shen, Q. Tetrahedron. 2007, 63, 8046 and references therein.
(13) Furstner, A. Chem. Soc. Rev. 2009, 38, 3208.
̈
(14) Bandini, M. Chem. Soc. Rev. 2011, 40, 1358.
(15) Boorman, T. C.; Larrosa, I. Chem. Soc. Rev. 2011, 40, 1910.
(16) Zeldin, R. M.; Toste, F. D. Chem. Sci. 2011, 2, 1706.
(17) Sherry, B. D.; Toste, F. D. J. Am. Chem. Soc. 2004, 126, 15978.
(18) Ferrer, C.; Echavarren, A. M. Angew. Chem., Int. Ed. 2006, 45,
1105.
(19) Lavallo, V.; Frey, G. D.; Kousar, S.; Donnadieu, B.; Bertrand, G.
Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 13569.
(20) Lo, V. K.-Y.; Wong, M.-K.; Che, C.-M. Org. Lett. 2008, 10, 517.
(21) Harrak, Y.; Simonneau, A.; Malacria, M.; Gandon, V.;
Fensterbank, L. Chem. Commun. 2010, 46, 865.
(22) Nun, P.; Gaillard, S.; Slawin, A. M. Z.; Nolan, S. P. Chem.
Commun. 2010, 46, 9113.
(23) Bolte, B.; Odabachina, Y.; Gagosz, F. J. Am. Chem. Soc. 2010,
132, 7294.
(24) Li, G.; Liu, Y. J. Org. Chem. 2010, 75, 3526.
(25) Wang, D.; Gautam, L. N. S.; Bollinger, C.; Harris, A.; Li, M.; Shi,
X. Org. Lett. 2011, 13, 2618.
(26) Wang, D.; Zhang, Y.; Cai, R.; Shi, X. Beilstein J. Org. Chem. 2011,
7, 1014.
(27) Georgy, M.; Boucard, V.; Campagne, J.-M. J. Am. Chem. Soc.
2005, 127, 14180.
(28) Georgy, M.; Boucard, V.; Debleds, O.; Zotto, C. D.; Campagne,
J.-M. Tetrahedron 2009, 65, 1758.
(29) Liu, J.; Muth, E.; Florke, U.; Henkel, G.; Merz, K.; Sauvageau, J.;
̈
Schwake, E.; Dyker, G. Adv. Synth. Catal. 2006, 348, 456.
(30) Kabalka, G. W.; Yao, M.-L. Curr. Org. Synth. 2008, 5, 28.
(31) Debleds, O.; Gayon, E.; Vrancken, E.; Campagne, J.-M. Beistein
J. Org. Chem. 2011, 7, 866.
(32) Biannic, B.; Aponick, A. Eur. J. Org. Chem. 2011, 6605.
(33) Glover, C.; Bagey, M. C. Molecules 2010, 15, 3221.
(34) Ye, L.; Zhang, L. J. Am. Chem. Soc. 2010, 132, 8550.
(35) Kumar, M. P.; Liu, R.-S. J. Org. Chem. 2006, 71, 4951.
(36) Braun, R. U.; Thomas, J. J. M. Chem.Eur. J. 2006, 12, 9081.
(37) Scheekloth, J. S. Jr.; Crews, C. M. Eur. J. Org. Chem. 2007, 40.
(38) Maraval, V.; Chauvin, R. Eur. J. Org. Chem. 2008, 5144.
(39) Engel, D. A.; Dudley, G. B. Org. Lett. 2006, 8, 4027.
(40) Chen, D.-W.; Ochiai, M. J. Org. Chem. 1999, 64, 6804.
(41) Yan, W.; Wang, Q.; Chen, Y.; Petersen, J. L.; Shi, X. Org. Lett.
2010, 12, 3308.
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