Silver-Catalyzed Allylation of Ketones and Intramolecular Cyclization through Carbene Intermediates from Cyclopropenes under Ambient Conditions

Article abstract of DOI:10.1002/asia.201501196

Tandem C-C bond formation was achieved through silver-catalyzed ring-opening of cyclopropenes via carbene intermediates. The reaction of cyclopropenes in the presence of a silver catalyst gave indene derivatives under ambient conditions. In contrast, the

Full text of DOI:10.1002/asia.201501196

DOI: 10.1002/asia.201501196
Full Paper
Allylation
Silver-Catalyzed Allylation of Ketones and Intramolecular
Cyclization through Carbene Intermediates from Cyclopropenes
Under Ambient Conditions
Takeo Nakano,[a] Kohei Endo,*[b, c] and Yutaka Ukaji[a]
Abstract: Tandem CÀC bond formation was achieved
through silver-catalyzed ring-opening of cyclopropenes via
carbene intermediates. The reaction of cyclopropenes in the
presence of a silver catalyst gave indene derivatives under
ambient conditions. In contrast, the insertion of organozinc
reagents to silver carbene or allylic cation intermediates af-
forded allylmetal intermediates for the tandem allylation of
carbonyl compounds.
Introduction
pot. In 2005, Tamaru and co-workers reported the Pd-catalyzed
allylation reaction of imines using allylic alcohol as an allyl
source.[6] Further efficient methods for the generation of nucle-
ophilic allylation reagents bearing a variety of functional
groups or substituents are needed.
The allylation reaction is one of the most important and popu-
lar methods for CÀC bond formation.[1] The resulting homoal-
lylic alcohol products can be used as intermediates for the syn-
thesis of natural products.[2] The allylation reaction with allyl
halides mediated by a low valence metal, such as Mg, Zn, and
In, has become a practical method for the alkylation of carbon-
yl compounds.[3] In particular, Zn-mediated addition reactions
are some of the most effective methods for chemo- and ste-
reoselective CÀC bond formation.[4] Allylzinc reagents show
higher nucleophilicity toward carbonyl compounds than other
alkylzinc intermediates due to the formation of a six-mem-
bered transition state. However, there are several limitations
for the generation of allylzinc reagents, which require unstable
allyl halide derivatives. Therefore, further studies on the gener-
ation of allylmetal intermediates are necessary. Previously,
Oshima and co-workers reported the metal-mediated or -cata-
lyzed retro-allylation of homoallylic alcohols with the genera-
tion of allylmetal intermediates.[5] The subsequent allylation re-
action of aldehydes gave various homoallylic alcohols in one-
We previously reported a CÀC bond cleavage and formation
sequence using cyclopropenes to form allylzinc intermediates,
the nucleophilic attack of which gives various hydrazines, ho-
moallylic alcohols, and amines (Scheme 1).[7] In these reports,
Scheme 1. Previous working hypothesis.
the initial step is thought to be the carbozincation of cyclopro-
penes, as Richey and co-workers reported the sequential car-
bometalation and ring-opening of cyclopropenes using orga-
noaluminum reagents for the generation of allylaluminum in-
termediates.[8] However, our studies on the Cu-catalyzed carbo-
metalation of cyclopropenes to give cyclopropylzinc intermedi-
ates for the sequential ring-opening of cyclopropyl metal
intermediates were unsuccessful after extensive screening of
the reaction conditions.[9] Recently, the generation of carbene
complexes from cyclopropenes has been reported; gold car-
bene complexes from cyclopropenes typically react with vari-
ous nucleophiles.[10–12] Furthermore, Fischer-type carbene com-
plexes gave various cyclic products via the nucleophilic attack
of lithium and sodium enolates.[13] In this context, the insertion
of a carbene intermediate derived from a cyclopropene into
a dialkylzinc seems to be an alternative approach for the gen-
eration of allylzinc intermediates.
[a] Dr. T. Nakano, Prof. Dr. Y. Ukaji
Division of Material Sciences
Graduate School of Natural Science and Technology
Kanazawa University
Kakuma, Kanazawa 920-1192 (Japan)
[b] Prof. Dr. K. Endo
Department of Chemistry
Faculty of Science
Tokyo University of Science
Kagurazaka, Shinjuku, 162-8601, Tokyo (Japan)
[c] Prof. Dr. K. Endo
PRESTO
Japan Science and Technology Agency (JST)
4-1-8 Honcho Kawaguchi, Saitama, 332-0012 (Japan)
E-mail: kendo@rs.tus.ac.jp
Our alternative proposal for the allylation reaction using cy-
clopropenes and organozinc reagents includes metal carbene
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/asia.201501196.
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(Table 1, entry 7). The in situ-generated [Au(PPh3)OTf] catalyst
gave the desired product in low yield as a mixture of re-
gioisomers (Table 1, entry 8). Other catalysts, such as Zn, Cu,
and Rh gave good results (Table 1, entries 9–11). The screening
of solvents showed that CH2Cl2 is the most suitable medium
for the present reaction (Table 1, entries 12 and 13).
Scheme 2. Alternative approach to allylation using cyclopropenes.
Under the optimized reaction conditions, the scope of cyclo-
propenes was investigated (Table 2). Various 3,3-diaryl cyclo-
propenes 1a, 1b, 1c, and 1d gave the indene products 2a,
2b, 2c, and 2d in high yields, respectively (Table 2, entries 1–
4). 1,2-Disubstitued cyclopropene 1e could be used in the
present reaction (Table 2, entry 5). When 3,3-alkyl,aryl cyclopro-
pene 1 f was used, the desired product 2 f was also obtained
in good yield (Table 2, entry 6). The unsymmetrical 3,3-diaryl
cyclopropenes 1g and 1h gave a mixture of products (Table 2,
entries 7 and 8). In these cases, selectivity was not observed.
intermediates (Scheme 2). The allylmetal intermediate would
be obtained via the intramolecular shift of an alkyl group de-
rived from an organozinc reagent. In this reaction, generation
of a carbene intermediate is considered to be a key step.
Therefore, the screening of transition metal catalysts to gener-
ate carbene intermediates from cyclopropenes was carried out.
Results and Discussion
The screening of effective catalysts for the generation of car-
bene intermediates, which took part in the intramolecular cyc-
lization to give indene derivatives, was performed (Table 1).
Table 2. Synthesis of various indenes.
Table 1. Screening of catalysts for indene.
Entry Cyclopropene
Product: Yield [%]
1
Entry
Catalyst
AgOTf
AgOAc
AgNO3
AgF
Ag2CO3
Ag2O
[Au(PPh3)Cl]
[Au(PPh3)Cl] (5 mol%)
AgOTf (5 mol%)
ZnI2
Solvent
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
2a/2a’ Yield [%]
1
2
3
4
5
6
7
8
96/–
95/–
92/–
93/–
15/–
nr
2
3
4
nr
7/14
9
CH2Cl2
CH2Cl2
CH2Cl2
toluene
THF
71/–
84/–
93/–
62/–
73/–
10
11
12
13
CuI
[RhCl(cod)]2
AgOTf
AgOTf
5
6
The synthesis of indenes using cyclopropenes has been report-
ed in the presence of cationic Au or Pd catalysts.[14] In contrast,
the generation of carbene or allylic cation intermediates in the
presence of a Ag catalyst was already known; thus, we focused
on the use of silver salts in the present tandem allylation reac-
tion using cyclopropenes.[15,16] The effective silver catalysts
were confirmed for the indene syntheses via carbene or allylic
cation intermediates derived from cyclopropenes. The reaction
of cyclopropene 1a in the presence of a Ag catalyst, such as
AgOTf, AgOAc, AgNO3, and AgF, gave the indene product 2a
in high yield even at room temperature (Table 1, entries 1–4).
However, when Ag2CO3 was used, product 2a was obtained in
lower yield (Table 1, entry 5). Indene was not formed in the
presence of Ag2O as a catalyst (Table 1, entry 6). The use of
[Au(PPh3)Cl] catalyst did not give the desired product at all
7
8
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The synthesis of indenes was carried out using deuterated
cyclopropene d-1a. The indene product d-2a was obtained in
good yield from cyclopropene d-1a [Eq. (1)]. When a mixture
of 1a and d-1a was used, a mixture of 2a and d-2a was ob-
tained in the same ratio after the reaction had proceeded half-
way [Eq. (2)]. These results suggested that CÀH bond cleavage
might not be the rate-determining step in the present reac-
tion. Therefore, a Friedel–Crafts-type reaction could occur to
give the indene product.
Table 3. Optimization for tandem allylation.
Entry
X [equiv]
Catalyst
Yield [%]
1
2
3[a]
4
5
6
7
8
1.1
1.1
1.1
1.1
1.1
1.1
2.0
3.0
1.1
1.1
1.1
1.1
1.1
–
<24
40
31
43
35
54
74
91
51
33
nd
22
38
AgOTf (5 mol%)
AgOTf (5 mol%)
[Au(PPh3)Cl] (5 mol%)+AgOTf (5 mol%)
[Au(PPh3)Cl] (5 mol%)
AgOAc (5 mol%)
AgOAc (5 mol%)
AgOAc (5mol%)
Ag2CO3 (5 mol%)
AgNO3 (5 mol%)
9
10
11
12
13
AgSbF6 (5 mol%)
ZnI2 (20 mol%)
ZnI2 (100 mol%)
[a] Toluene was used as a solvent.
We expected that the present catalyst system might be suit-
able for the reaction using simple non-functionalized cyclopro-
penes instead of 1i bearing an acetal moiety, although the
previous conditions gave poor results (Table 4). To our delight,
the cyclopropene 1j gave the homoallylic alcohol 4ja in 77%
yield as a diastereomeric mixture (Table 4, entry 1). The reac-
tion of cyclopropene 1k also gave the desired product 4ka,
however, 1 f bearing a bulky group did not give the corre-
sponding product 4 fa (Table 4, entries 2 and 3). The cyclopro-
pene 1l bearing a 1-naphthyl group gave the product 4la in
lower yield due to steric hindrance (Table 4, entry 4). The cyclo-
propene 1a also gave the product 4aa in good yield (Table 4,
entry 5); however, cyclopropene 1b did not give the desired
product (Table 4, entry 6). The cyclopropenes 1c and 1d bear-
ing electron-withdrawing groups gave the desired products
4ca and 4da, respectively, in moderate yields (Table 4, en-
tries 7 and 8). However, with cyclopropene 1m, the corre-
sponding product was not obtained at all (Table 4, entry 9).
The scope of the reaction using ketones as an electrophile
was examined under the present catalyst system (Table 5). The
reaction of cyclopropene 1j and ketones 3b, 3c, 3d, 3e, and
3 f gave the homoallylic alcohols 4jb, 4jc, 4jd, 4je, and 4jf, re-
spectively, in good yields (Table 5, entries 1–5). The dioxanone
3g could be used in the present reaction to give the densely
functionalized product 4jg (Table 5, entry 6). When 3-penta-
none 3h was used, a mixture of 4jh and regioisomer 5jh was
obtained (Table 5, entry 7). Furthermore, the bulky ketones 3i,
3j, and 3k gave the products 5ji, 5jj, and 5jk, respectively
(Table 5, entries 8–10).[19] Steric hindrance might inhibit the cre-
ation of consecutive quaternary centers.
The silver-catalyzed generation of carbene intermediates
from cyclopropenes under ambient conditions prompted us to
further investigate the generation of allylmetal intermediates
via the insertion of organometallic reagents into carbene inter-
mediates for the tandem allylation reaction of carbonyl com-
pounds. Accordingly, optimization of the reaction conditions
for the allylation of aldehydes was carried out using Ag cata-
lysts (Table 3). The cyclopropene 1i was chosen as a model
substrate for the present allylation reaction; in our previous
report, the allylation reaction proceeded smoothly when cyclo-
propene 1i bearing an acetal moiety was used.[7] When the al-
lylation reaction was performed without any catalyst, the de-
sired product 4ia was obtained in low yield as a mixture of un-
identified by-products; the Zn-mediated generation of a carbe-
noid intermediate or a simple carbozincation/ring-opening se-
quence might take place (Table 3, entry 1). When AgOTf was
used, the product 4ia was obtained in moderate yields
(Table 3, entries 2 and 3). The yields did not increase in the
presence of a Au catalyst (Table 3, entries 4 and 5). These re-
sults suggested that a Ag catalyst is essential for the present
allylation reaction. Therefore, screening of Ag catalysts was car-
ried out (Table 3, entries 6–11). The use of AgOAc as a catalyst
gave the desired product 4ia in 54% yield. When the amount
of 1i and Et2Zn was increased, 4ia was obtained in 91% yield
(Table 3, entry 8); the previous method gave a comparable
result with the use of excess 1i and Et2Zn.[7b] On the other
hand, ZnI2 showed low catalytic activity compared with a Ag
catalyst (Table 3, entries 12 and 13).[17,18]
The generation of products 5 suggested that the present re-
action includes the isomerization of allylmetal intermediates
(Scheme 3). Namely, the nucleophilic attack of allylmetal inter-
mediates I derived from cyclopropenes 1 to ketones could
take place to give the products 4. However, bulky ketones in-
hibit the nucleophilic attack of allylmetal intermediates I due
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Table 4. Scope of cyclopropenes.
Table 5. Scope of ketones.
Entry
1
Cyclopropene
Yield [%]
Entry
1
Ketone
Yield [%]
77 (4ja)[a]
67 (4jb)
2
3
4
5
6
63 (4ka)[b]
2
3
4
5
83 (4jc)[a]
51 (4jd)[b]
86 (4je)
88 (4jf)
trace
32 (4la)[c]
56 (4aa)
nd[d]
6
78 (4jg)
7
33 (4ca)
7
8
38 (4jh), 21 (5jh)
55 (5ji)
8
9
48 (4da)
nd
9
58 (5jj)
27 (5jk)
[a] d.r.=1.4:1. [b] d.r.=4:1. [c] d.r.=5:3. [d] Indene product 2b was ob-
served.
10
[a] d.r.=2:1. [b] d.r.=10:9.
to the steric hindrance. Therefore, the isomerization of allylme-
tal intermediates I to allylmetal intermediate II would occur,
followed by the allylation to bulky ketones to give the re-
gioisomers 5.
The rationale for the high stereoselectivity of the olefinic ge-
ometry seems to be the formation of the six-membered transi-
tion states: TS-I or TS-III; a larger substituent, such as Et or Ph,
should be placed at the equatorial positions (Figure 1). A bulky
substituent at the axial positions gives unfavorable TS-II or TS-
IV due to steric hindrance.
When an unsymmetrical ketone, such as acetophenone 3c,
was used, the product 4jc was obtained as a diastereomeric
mixture, as shown in Table 5. In this case, the allylation reaction
might proceed via TS-V, VI, VII, and VIII (Figure 2). A diastereo-
meric mixture 4jc-A and 4jc-B was obtained due to the steric
repulsion between Me and Ph at the axial or equatorial posi-
tions.
When cyclopropene 1i was used for the addition to aceto-
phenone 3c, the corresponding product 6ic was obtained in
low yield after deprotection of the acetal moiety [Eq. (3)]. This
result suggested that an intramolecular coordination of the
acetal moiety on a metal-center might stabilize the allylmetal
intermediates. Therefore, the allylmetal intermediates derived
from 1j showed higher reactivity in the addition to ketones
(Figure 3).
In preliminary experiments, other electrophiles were exam-
ined for the development of tandem reactions using allylmetal
intermediates via cyclopropenes. The allylation reaction using
benzoylchloride as an electrophile gave the ketone product 7
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in moderate yield [Eq. (4)]. On the other hand, when benze-
neacetonitrile was used, a trace amount of the ketone product
8 was observed, but could not be isolated [Eq. (5)].
Scheme 3. Generation of regioisomer 5.
Figure 3. Reactivity of allylmetal intermediates.
A proposed mechanism for the present reaction is shown in
Figure 4. The vinylcarbenoid A-1 is generated from cyclopro-
pene 1 in the presence of a Ag catalyst. There are several re-
ports for the generation of a silver–carbene complexes derived
from cyclopropenes; the allylic cation intermediates A-2 and/
or A-3 seem to be other candidates for the active intermedi-
ates in the present reaction.[15,20] When AgOTf is used, the Frie-
del–Crafts-type reaction occurs to give the indene product 2
via intermediate B. In the allylation reaction, allylmetal interme-
Figure 1. E-selectivity of products.
Figure 2. Transition state model for diastereoselectivity.
Figure 4. Proposed mechanism.
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(m, 1H), 7.02–7.08 (m, 2H), 7.13–7.16 (m, 1H), 7.32–7.36 (m, 1H),
7.42–7.47 ppm (m, 2H); 13C NMR (100 MHz, CDCl3): d=38.1, 111.7
(d, J=22.9 Hz), 113.1 (d, J=22.9 Hz), 115.5 (d, J=21.0 Hz), 120.6 (d,
J=9.5 Hz), 129.2 (d, J=7.6 Hz), 130.3, 131.9, 139.7, 143.5, 146.7 (d,
J=8.8 Hz), 161.5 (d, J=242 Hz), 162.4 ppm (d, J=245 Hz); 19F NMR
(376 MHz, CDCl3): d=À118.34, À114.19 ppm; IR (neat): n˜ =3066,
2887, 1613, 1581, 1506, 1475, 1409, 1390, 1236, 1157, 1141, 1124,
1095, 950, 924, 841, 812, 776, 761 cmÀ1; HRMS (APCI) m/z calcd.
C15H10F2 228.0751 [M+]; found: 228.0748.
diate C is generated with an organozinc reagent. The allylation
reaction of carbonyl compounds proceeded to give the desired
product 4. In the present reaction, only nucleophilic attack of
an allylmetal intermediate proceeded chemoselectively with-
out the addition of organozinc reagent R3 Zn. We currently
2
cannot exclude the presence of allylsilver intermediates for the
allylation of carbonyl compounds.
6-Chloro-3-(4-chlorophenyl)-1H-indene (2d) (74.8 mg, 0.28 mmol)
was obtained in 96% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3): d=3.40 (d, J=2.3 Hz, 2H), 6.48 (t, J=2.3 Hz, 1H), 7.20–7.22
(m, 1H), 7.32–7.35 (m, 3H), 7.39–7.42 ppm (m, 3H); 13C NMR
(100 MHz, CDCl3): d=38.0, 120.8, 124.5, 126.4, 128.8 (2 carbons
overlapped), 131.2, 131.5, 133.6, 134.0, 142.0, 143.5, 146.3 ppm; IR
(neat): n˜ =3065, 2884, 1654, 1600, 1564, 1488, 1459, 1418, 1388,
1187, 1143, 1090, 1068, 1014, 973, 939, 872, 835, 776, 752,
685 cmÀ1; HRMS (APCI) m/z calcd. C15H10Cl2 260.0160 [M+]; found:
260.1059.
Conclusions
A Ag-catalyzed tandem allylation reaction and Friedel–Crafts-
type reaction for the synthesis of indenes have been devel-
oped. These reactions involve the generation of a vinyl carbe-
noid or cationic intermediates from cyclopropenes in the pres-
ence of a Ag catalyst. The addition of organozinc reagents
gave allylmetal intermediates, which in turn gave homoallylic
alcohols via an allylation reaction. The present results for the
generation of carbene intermediates under ambient conditions
may be useful for the further development of tandem reac-
tions including an asymmetric version using a variety of nucle-
ophiles.
1,2-Dimethyl-3-phenyl-1H-indene (2e) (62.6 mg, 0.28 mmol) was
1
obtained in 95% yield as a colorless oil; H NMR (400 MHz, CDCl3):
d=1.31 (d, J=7.8 Hz, 3H), 1.98 (s, 3H), 3.29 (q, J=7.8 Hz, 1H),
7.07–7.16 (m, 3H), 7.25–7.29 (m, 1H), 7.32–7.40 ppm (m, 5H);
13C NMR (100 MHz, CDCl3): d=12.9, 15.8, 47.4, 119.2, 122.5, 124.1,
126.3, 126.9, 128.3, 129.2, 135.5, 137.1, 144.9, 145.6, 148.2 ppm; IR
(neat): n˜ =3018, 2964, 2927, 2868, 1597, 1493, 1463, 1442, 1158,
1074, 1023, 934, 772, 701, 658 cmÀ1; HRMS (APCI) m/z calcd. C17H16
220.1252 [M+]; found: 220.1250.
Experimental Section
1
General Method: H NMR was recorded on a 400 MHz NMR spec-
trometer (JEOL ECS 400). Chemical shifts d are reported in ppm
using TMS as an internal standard. Data are reported as follows:
chemical shift, multiplicity (s=singlet, d=doublet, t=triplet, q=
quartet, m=multiplet), coupling constant (J) and integration.
13C NMR spectra were recorded on at 100 MHz. The chemical shifts
were determined in the d-scale relative to CDCl3 (d=77.0 ppm).
The wave numbers of maximum absorption peaks of IR spectrosco-
py are presented in cmÀ1. HRMS (APCI or ESI, positive) was mea-
sured with a TOF mass spectrometer. All of the melting points
were measured with a micro melting point apparatus. All solvents
were distilled and stored over drying agents.
3-Isopropyl-1H-indene (2 f) (29.8 mg, 0.18 mmol) was obtained in
63% yield as a colorless oil; H NMR (400 MHz, CDCl3): d=1.21 (d,
1
J=6.9 Hz, 6H), 2.83–2.90 (m, 1H), 3.24 (s, 2H), 6.12 (s, 1H), 7.10–
7.13 (m, 1H), 7.20–7.24 (m, 1H), 7.32–7.34 (m, 1H), 7.37–7.39 ppm
(m, 1H); 13C NMR (100 MHz, CDCl3): d=21.9, 26.9, 37.5, 119.3,
123.8, 124.3, 125.3, 125.8, 144.8, 145.0, 151.0 ppm; IR (neat): n˜ =
3067, 3017, 2961, 2871, 1605, 1457, 1395, 1381, 1158, 1110, 1015,
968, 915, 766, 720 cmÀ1; HRMS (ESI-TOF) m/z calcd. C12H15 159.1174
[M+H+]; found: 159.1173.
A mixture of 4-methyl-3-phenyl-1H-indene (2g) and 3-(o-Tolyl)-1H-
indene (2g’) (45.6 mg, 0.22 mmol) was obtained in 97% yield in
1
a 3:1 ratio as a colorless oil; for 2g: H NMR (400 MHz, CDCl3): d=
1.93 (s, 3H), 3.38 (d, J=1.8 Hz, 2H), 6.28 (t, J=1.8 Hz, 1H), 6.93–
6.95 (m, 1H), 7.04–7.08 (m, 1H), 7.13–7.32 ppm (m, 6H); 13C NMR
(100 MHz, CDCl3): d=20.3, 38.0, 121.7, 124.9, 127.0, 127.8, 128.9,
General Procedure (Preparation of 2b)
To a suspension of AgOTf (3.9 mg, 0.015 mmol) in CH2Cl2 (1.5 mL),
cyclopropene 1b (66.0 mg, 0.3 mmol) was added at room tempera-
ture. The reaction mixture was stirred for 18 h and was quenched
with sat. NH4Cl. The aqueous layer was separated and extracted
with CHCl3. The combined organic layer was dried over Na2SO4,
concentrated, and purified by silica gel column chromatography
(n-hexane) to afford 2b (60.7 mg, 0.27 mmol) in 92% yield. In a sim-
ilar manner, indene derivatives 2a,[14b] 2c, 2d, 2e, 2 f, 2g, 2g’, 2h,
2h’, and d-2a were obtained.
1
129.0, 131.5, 132.6, 139.2, 142.4, 144.8, 146.9 ppm; for 2g’: H NMR
(400 MHz, CDCl3): d=2.18 (s, 3H), 3.46 (d, J=1.8 Hz, 2H), 6.35 (t,
J=1.8 Hz, 1H), 7.04–7.08 (m, 1H), 7.13–7.32 (m, 6H), 7.45–
7.47 ppm (m, 1H); 13C NMR (100 MHz, CDCl3): d=20.2, 38.4, 120.5,
123.8, 124.7, 125.6, 126.1, 127.5, 129.4, 130.2, 131.6, 135.7, 136.4,
143.9, 145.0, 145.2 ppm; IR (neat): n˜ =3422, 3058, 2923, 1654, 1594,
1542, 1509, 1490, 1457, 1389, 765, 701 cmÀ1; HRMS (APCI) m/z
calcd. C16H14 206.1096 [M+]; found: 206.1093.
6-Methyl-3-(p-tolyl)-1H-indene (2b) was obtained as a colorless oil;
1H NMR (400 MHz, CDCl3): d=2.32 (s, 3H), 2.34 (s, 3H), 3.37 (d, J=
1.8 Hz, 2H), 6.39 (t, J=1.8 Hz, 1H), 7.04–7.06 (m, 1H), 7.15–7.18 (m,
2H), 7.26 (s, 1H), 7.38–7.43 ppm (m, 3H); 13C NMR (100 MHz,
CDCl3): d=21.2, 21.4, 37.9, 120.0, 125.0, 126.8, 127.5, 129.2, 129.4,
133.4, 134.4, 137.2, 141.4, 144.8, 145.1 ppm; IR (neat): n˜ =3440,
3022, 2918, 1655, 1609, 1570, 1508, 1475, 1449, 1390, 1183, 1109,
1037, 970, 941, 867, 825, 770 cmÀ1; HRMS (APCI) m/z calcd. C17H16
220.1252 [M+]; found: 220.1250.
A mixture of 3-(4-fluorophenyl)-1H-indene (2h) and 6-fluoro-3-
phenyl-1H-indene (2h’) (60.4 mg, 0.28 mmol) was obtained in 96%
yield in a 1:1 ratio as a colorless oil; H NMR (400 MHz, CDCl3): d=
1
3.40–3.43 (m, 2H), 6.45–6.47 (m, 1H), 6.85–7.51 ppm (m, 8H);
13C NMR (100 MHz, CDCl3): d=38.1, 111.7 (d, J=22.9 Hz), 113.1 (d,
J=22.9 Hz), 115.5 (d, J=21.0 Hz), 120.1, 120.8 (d, J=8.6 Hz), 124.1,
124.9, 126.2, 127.6, 127.7, 128.6, 129.3 (d, J=7.6 Hz), 130.3, 130.9,
132.1, 135.8, 139.9, 143.8, 144.2, 144.5, 144.7, 146.8 (d, J=8.6 Hz),
161.5 (d, J=241 Hz), 162.3 ppm (d, J=246 Hz); 19F NMR (376 MHz,
CDCl3): d=À118.56, À114.50 ppm; IR (neat): n˜ =3064, 2884, 2768,
1890, 1655, 1613, 1596, 1505, 1475, 1445, 1390, 1274, 1234, 1157,
1141, 1123, 1095, 1081, 1024, 972, 948, 922, 841, 814, 765,
6-Fluoro-3-(4-fluorophenyl)-1H-indene (2c) (66.3 mg, 0.29 mmol)
was obtained in 97% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3): d=3.39 (d, J=1.8 Hz, 2H), 6.41 (t, J=1.8 Hz, 1H), 6.91–6.96
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720 cmÀ1; HRMS (APCI) m/z calcd. C15H11F 210.0845 [M+]; found:
210.0843.
(d, J=3.2 Hz, 1H), 5.25 (dt, J=15.6, 6.4 Hz, 1H), 5.80 (d, J=15.6 Hz,
1H), 7.01–7.34 ppm (m, 10H); (minor): d=0.66 (t, J=7.3 Hz, 3H),
1.00 (t, J=7.4 Hz, 3H), 1.73–1.90 (m, 2H), 2.05–2.18 (m, 3H), 4.85
(d, J=5.5 Hz, 1H), 5.57 (d, J=16.0 Hz, 1H), 5.67 (dt, J=16.0, 6.0 Hz,
1H), 6.69–6.71 (m, 2H), 7.01–7.34 ppm (m, 8H); 13C NMR (100 MHz,
CDCl3): d=8.8, 13.7, 14.0, 26.3, 27.9, 28.0, 53.7, 53.9, 80.1, 80.3,
126.2, 127.0, 127.1, 127.4, 127.5, 128.0, 128.2, 128.4, 128.5, 129.3,
131.0, 134.1, 134.3, 140.5, 140.6, 141.1, 143.1 ppm; IR (neat): n˜ =
3453, 3086, 3058, 3029, 2964, 2932, 2857, 1946, 1654, 1600, 1493,
1453, 1378, 1188, 1083, 1042, 988, 914, 756, 701, 670 cmÀ1; HRMS
(ESI-TOF) m/z calcd. C20H24NaO 303.1723 [M+Na+]; found:
303.1723.
3-(Phenyl-d5)-1H-indene-1,4,5,6,7-d5 (d-2a) (49.0 mg, 0.24 mmol)
was obtained in 81% yield as a colorless oil; H NMR (400 MHz,
CDCl3): d=3.43 (d, J=2.3 Hz, 1H), 6.50 ppm (d, J=2.3 Hz, 1H);
13C NMR (100 MHz, CDCl3): d=37.8 (t, J=19.1 Hz), 119.9 (t, J=
24.8 Hz), 123.7 (t, J=24.8 Hz), 124.3 (t, J=23.8 Hz), 125.6 (t, J=
23.8 Hz), 127.0 (t, J=23.8 Hz), 127.4 (t, J=23.8 Hz), 128.0 (t, J=
23.8 Hz), 130.9, 136.0, 143.9, 144.6, 145.2 ppm; IR (neat): n˜ =2923,
2275, 1654, 1560, 1375, 1247, 1017, 927, 853, 821, 769, 731 cmÀ1
;
HRMS (ESI-TOF) m/z calcd. C15H3D10 203.1645 [M+H+]; found:
203.1643.
(E)-2-Methyl-2-(naphthalen-1-yl)-1-phenylhex-3-en-1-ol
(4la)
(30.1 mg, 0.09 mmol) was obtained in 32% yield as a colorless oil;
1H NMR (400 MHz, CDCl3) (major): d=0.87 (t, J=7.3 Hz, 3H), 1.38
(s, 3H), 1.97–2.05 (m, 2H), 2.26 (d, J=4.6 Hz, 1H), 5.16 (dt, J=15.6,
6.9 Hz, 1H), 5.61 (d, J=4.6 Hz, 1H), 5.87 (d, J=15.6 Hz, 1H), 6.78–
6.79 (m, 2H), 7.01–7.10 (m, 2H), 7.23–7.44 (m, 5H), 7.66–7.68 (m,
General Procedure (Preparation of 4aa)
To a suspension of AgOAc (2.5 mg, 0.015 mmol) in CH2Cl2 (1.5 mL),
cyclopropene 1a (173.0 mg, 0.9 mmol), Et2Zn (0.9 mL, 1.0m in tolu-
ene), and benzaldehyde (31.8 mL, 0.3 mmol) were added at room
temperature. The reaction mixture was stirred for 18 h and was
quenched with a sat. NH4Cl. The aqueous layer was separated and
extracted with CHCl3. The combined organic layer was dried over
Na2SO4, concentrated, and purified by silica gel column chromatog-
raphy (hexane/AcOEt=20:1) to afford 4aa (55.0 mg, 0.16 mmol) in
56% yield.
1
1H), 7.78–7.82 (m, 1H), 8.33–8.35 ppm (m, 1H); H NMR (400 MHz,
CDCl3) (minor): d=0.72 (t, J=7.3 Hz, 3H), 1.46 (s, 3H), 1.78–1.86
(m, 2H), 4.96 (dt, J=16.0, 6.4 Hz, 1H), 5.54 (d, J=2.3 Hz, 1H), 5.77
(d, J=16.0 Hz, 1H), 6.78–6.79 (m, 2H), 7.01–7.10 (m, 2H), 7.23–7.44
(m, 5H), 7.61–7.62 (m, 1H), 7.74–7.76 (m, 1H), 8.41–8.43 ppm (m,
1H), OH proton was not observed clearly; 13C NMR (100 MHz,
CDCl3): d=13.5, 13.6, 23.1, 23.9, 25.9, 26.0, 50.4, 51.1, 77.2, 77.8,
124.2, 124.3, 124.6, 124.9, 125.0, 126.0, 127.0, 127.1, 127.3, 127.4,
127.5, 127.6, 128.1, 128.5, 128.6, 129.3, 129.4, 130.9, 131.5, 132.9,
134.0, 134.3, 134.4, 135.0, 135.3, 140.5, 140.6, 141.3 ppm; IR (neat):
n˜ =3448, 3029, 2961, 2929, 1654, 1600, 1508, 1492, 1452, 1396,
(E)-1,2,2-Triphenylhex-3-en-1-ol (4aa) was obtained as a colorless
1
oil; H NMR (400 MHz, CDCl3): d=0.93 (t, J=7.3 Hz, 3H), 2.02–2.09
(m, 2H), 2.40 (br, 1H), 5.08 (dt, J=16.0, 6.0 Hz, 1H), 5.47 (s, 1H),
5.99 (d, J=16.0 Hz, 1H), 6.70–6.72 (m, 2H), 6.99–7.32 ppm (m,
13H); 13C NMR (100 MHz, CDCl3): d=13.6, 26.0, 59.6, 77.9, 126.2,
126.3, 127.0, 127.2, 127.4, 127.7, 128.3, 129.2, 130.6, 131.1, 137.6,
140.7, 143.8, 145.1 ppm; IR (neat): n˜ =3547, 3057, 3030, 2961, 2929,
1654, 1599, 1494, 1444, 1379, 1186, 1083, 1042, 910, 732, 700 cmÀ1
HRMS (ESI-TOF) m/z calcd. C24H24NaO 351.1725 [M+Na+]; found:
1374, 1186, 1023, 975, 939, 909, 799, 778, 758, 734, 704 cmÀ1
;
HRMS (ESI-TOF) m/z calcd. C23H24NaO 339.1725 [M+Na+]; found:
339.1728.
;
(E)-2,3-Dimethyl-3-phenylhept-4-en-2-ol (4jb) (44.0 mg, 0.20 mmol)
was obtained in 67% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3): d=0.94 (t, J=7.3 Hz, 3H), 1.04 (s, 3H), 1.09 (s, 3H), 1.30 (br,
1H), 1.45 (s, 3H), 2.02–2.10 (m, 2H), 5.49 (dt, J=15.6, 6.4 Hz, 1H),
6.24 (d, J=15.6 Hz, 1H), 7.11–7.15 (m, 1H), 7.19–7.25 (m, 2H), 7.38–
7.41 ppm (m, 2H); 13C NMR (100 MHz, CDCl3): d=14.0, 20.9, 25.9,
26.1, 26.3, 50.3, 74.7, 126.0, 127.6, 128.5, 131.8, 134.1, 145.7 ppm;
IR (neat): n˜ =3473, 2966, 2931, 1654, 1598, 1541, 1495, 1458, 1371,
1113, 1028, 985, 952, 871, 755, 702 cmÀ1; HRMS (ESI-TOF) m/z calcd.
C15H22NaO 241.1568 [M+Na+]; found: 241.1564.
351.1731.
(E)-2,2-Bis(4-fluorophenyl)-1-phenylhex-3-en-1-ol (4ca) (36.0 mg,
0.09 mmol) was obtained in 33% yield as a colorless oil; H NMR
1
(400 MHz, CDCl3): d=0.92 (t, J=7.3 Hz, 3H), 1.97–2.10 (m, 2H),
2.28 (d, J=6.0 Hz, 1H), 5.03 (dt, J=15.6, 6.4 Hz, 1H), 5.37 (d, J=
6.0 Hz, 1H), 5.91 (d, J=15.6 Hz, 1H), 6.69–6.71 (m, 2H), 6.80–6.98
(m, 6H), 7.03–7.13 (m, 3H), 7.21–7.26 ppm (m, 2H); 13C NMR
(100 MHz, CDCl3): d=13.6, 26.0, 58.5, 78.2, 114.2 (d, J=21.0 Hz),
114.5 (d, J=21.0 Hz), 127.2, 127.5, 128.2, 130.8 (d, J=7.6 Hz), 131.2,
132.1 (d, J=7.6 Hz), 137.7, 139.3, 140.4, 140.8, 161.2 (d, J=244 Hz),
161.5 ppm (d, J=244 Hz); 19F NMR (376 MHz, CDCl3): d=À116.44,
À116.31 ppm; IR (neat): n˜ =3448, 3032, 2962, 2927, 1603, 1508,
1455, 1232, 1162, 1108, 1044, 911, 835, 764, 734, 703 cmÀ1; HRMS
(ESI-TOF) m/z calcd. C24H22F2NaO 387.1536 [M+Na+]; found:
387.1535.
(E)-3-Methyl-2,3-diphenylhept-4-en-2-ol (4jc) (69.5 mg, 0.24 mmol)
was obtained in 83% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3) (major): d=0.90 (t, J=7.4 Hz, 3H), 1.37 (s, 3H), 1.45 (s, 3H),
1.89 (s, 1H), 1.97–2.08 (m, 2H), 5.40 (dt, J=15.6, 6.4 Hz, 1H), 6.30
(d, J=15.6 Hz, 1H), 7.00–7.20 ppm (m, 10H); (minor): d=0.92 (t,
J=7.8 Hz, 3H), 1.35 (s, 3H), 1.49 (s, 3H), 1.86 (s, 1H), 1.97–2.08 (m,
2H), 5.40 (dt, J=15.6, 6.4 Hz, 1H), 6.30 (d, J=15.6 Hz, 1H), 7.00–
7.20 ppm (m, 10H); 13C NMR (100 MHz, CDCl3): d=13.8, 20.9, 21.1,
25.8, 26.1, 26.2, 26.3, 50.8, 78.2, 78.4, 126.2, 126.4, 126.5, 126.6,
126.7, 127.1, 127.2, 127.26, 127.30, 128.8, 132.1, 132.2, 133.3, 133.5,
144.5, 144.7, 144.8, 144.9 ppm; IR (neat): n˜ =3567, 3089, 3056,
2961, 1654, 1599, 1493, 1444, 1372, 1170, 1069, 1027, 986, 906,
759, 701 cmÀ1; HRMS (ESI-TOF) m/z calcd. C20H24NaO 303.1725
[M+Na+]; found: 303.1727.
(E)-2,2-Bis(4-chlorophenyl)-1-phenylhex-3-en-1-ol (4da) (56.8 mg,
0.14 mmol) was obtained in 48% yield as a white solid, M.p.=112–
1
113 8C (from AcOEt/hexane); H NMR (400 MHz, CDCl3): d=0.91 (t,
J=7.8 Hz, 3H), 2.00–2.07 (m, 2H), 2.26 (br, 1H), 5.03 (dt, J=15.6,
6.4 Hz, 1H), 5.36 (s, 1H), 5.87 (d, J=15.6 Hz, 1H), 6.70–6.72 (m, 2H),
6.91–6.94 (m, 2H), 7.04–7.21 ppm (m, 9H); 13C NMR (100 MHz,
CDCl3): d=13.5, 26.0, 58.7, 78.0, 127.3, 127.5, 127.6, 127.9, 128.2,
130.7, 130.8, 131.9, 132.1, 132.4, 137.9, 140.2, 141.9, 143.4 ppm; IR
(neat): n˜ =3448, 2961, 1658, 1654, 1560, 1542, 1508, 1490, 1457,
1398, 1260, 1093, 1012, 801, 701 cmÀ1; HRMS (ESI-TOF) m/z calcd.
C24H22Cl2NaO 419.0945 [M+Na+]; found: 419.0941.
(E)-1,1,1-Trifluoro-3-methyl-2,3-diphenylhept-4-en-2-ol
(4jd)
(54.9 mg, 0.15 mmol) was obtained in 51% yield as a colorless oil;
1H NMR (400 MHz, CDCl3) (major): d=0.94 (t, J=7.3 Hz, 3H), 1.38
(s, 3H), 2.00–2.11 (m, 2H), 2.64 (s, 1H), 5.39 (dt, J=15.6, 6.4 Hz,
1H), 6.54 (d, J=15.6 Hz, 1H), 7.13–7.34 ppm (m, 10H); (minor): d=
0.91 (t, J=7.8 Hz, 3H), 1.47 (s, 3H), 2.00–2.11 (m, 2H), 2.81 (s, 1H),
5.52 (dt, J=15.6, 6.4 Hz, 1H), 6.35 (d, J=15.6 Hz, 1H), 7.13–
(E)-2-Ethyl-1,2-diphenylhex-3-en-1-ol (4ka) (54.8 mg, 0.18 mmol)
was obtained in 63% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3) (major): d=0.51 (t, J=7.8 Hz, 3H), 0.95 (t, J=7.8 Hz, 3H),
1.50–1.66 (m, 2H), 1.91 (d, J=3.2 Hz, 1H), 2.05–2.18 (m, 2H), 5.05
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7.34 ppm (m, 10H); 13C NMR (100 MHz, CDCl3): d=1.01, 13.5, 21.5,
21.8, 26.1, 26.2, 49.9, 50.0, 81.3 (q, J=25.7 Hz), 81.5 (q, J=25.7 Hz),
126.9, 127.0, 127.1, 127.2, 127.4, 127.5, 127.6, 128.1, 128.2, 128.8,
129.0, 131.4, 131.9, 133.0, 133.5, 136.0, 136.3, 142.2, 142.9 ppm;
19F NMR (376 MHz, CDCl3): d=À67.5, À67.0 ppm; IR (neat): n˜ =
3552, 3059, 2963, 1955, 1654, 1600, 1496, 1446, 1377, 1260, 1153,
1062, 1030, 911, 794, 725, 701, 669 cmÀ1; HRMS (ESI-TOF) m/z
calcd. C20H21F3NaO 357.1442 [M+Na+]; found: 357.1445.
696 cmÀ1; HRMS (ESI-TOF) m/z calcd. C17H26NaO 269.1881 [M+
Na+]; found: 269.1876.
(E)-2-Ethyl-1,1,4-triphenylpent-3-en-1-ol (5ji) (56.5 mg, 0.16 mmol)
was obtained in 55% yield as a white solid; M.p.=104–1058C
(from AcOEt/hexane); 1H NMR (400 MHz, CDCl3): d=0.85 (t, J=
7.4 Hz, 3H), 1.19–1.29 (m, 1H), 1.57–1.66 (m, 1H), 1.87 (s, 3H),
3.32–3.38 (m, 1H), 5.52 (d, J=10.6 Hz, 1H), 7.02–7.19 (m, 9H),
7.25–7.34 (m, 5H), 7.46–7.48 ppm (m, 2H); 13C NMR (100 MHz,
CDCl3): d=12.4, 16.9, 23.7, 48.9, 81.0, 125.8, 125.9, 126.2, 126.4,
126.6, 126.7, 127.7, 128.0, 128.1, 128.2, 137.4, 144.3, 146.3,
146.5 ppm; IR (neat): n˜ =3567, 3056, 2961, 2870, 1654, 1598, 1542,
1491, 1446, 1377, 1158, 1031, 877, 757, 698 cmÀ1; HRMS (ESI-TOF)
m/z calcd. C25H26NaO 365.1881 [M+Na+]; found: 365.1884.
(E)-1-(2-Phenylhex-3-en-2-yl)cyclopentanol
(4je)
(62.7 mg,
1
0.25 mmol) was obtained in 86% yield as a colorless oil; H NMR
(400 MHz, CDCl3): d=0.94 (t, J=7.4 Hz, 3H), 1.06 (br, 1H), 1.23–
1.27 (m, 1H), 1.32–1.37 (m, 1H), 1.42–1.52 (m, 2H), 1.46 (s, 3H)
1.62–1.83 (m, 4H), 2.01–2.08 (m, 2H), 5.50 (dt, J=16.0, 6.4 Hz, 1H),
6.10 (d, J=16.0 Hz, 1H), 7.11–7.15 (m, 1H), 7.19–7.24 (m, 2H), 7.40–
7.42 ppm (m, 2H); 13C NMR (100 MHz, CDCl3): d=14.0, 21.7, 24.0,
24.1, 26.3, 35.8, 36.3, 49.7, 87.0, 126.0, 127.6, 128.4, 132.2, 134.3,
146.0 ppm; IR (neat): n˜ =3461, 2960, 2870, 1654, 1597, 1542, 1495,
1443, 1374, 1196, 1095, 1000, 906, 758, 701 cmÀ1; HRMS (ESI-TOF)
m/z calcd. C17H24NaO 267.1725 [M+Na+]; found: 267.1718.
(E)-2-Benzyl-3-ethyl-1,5-diphenylhex-4-en-2-ol
(5jj)
(65.8 mg,
1
0.17 mmol) was obtained in 58% yield as a colorless oil; H NMR
(400 MHz, CDCl3): d=0.71 (t, J=7.3 Hz, 3H), 1.29–1.41 (m, 1H),
1.64 (s, 3H), 1.70 (br, 1H), 1.77–1.88 (m, 1H), 2.28–2.34 (m, 1H),
2.78–2.87 (m, 4H), 5.45 (d, J=10.6 Hz, 1H), 7.15–7.24 ppm (m,
15H); 13C NMR (100 MHz, CDCl3): d=12.6, 16.6, 23.7, 43.1, 43.8,
48.0, 76.9, 125.8, 126.2, 126.3, 126.9, 127.9, 128.0, 128.1, 128.2,
130.8, 130.9, 137.7, 137.8, 139.8, 143.7 ppm; IR (neat): n˜ =3548,
3082, 3059, 3026, 2959, 2871, 1945, 1878, 1803, 1601, 1493, 1453,
1378, 1181, 1155, 1125, 1081, 1030, 940, 925, 873, 782, 755,
699 cmÀ1; HRMS (ESI-TOF) m/z calcd. C27H30NaO 393.2194 [M+
Na+]; found: 393.2196.
(E)-1-(2-Phenylhex-3-en-2-yl)cyclohexanol
(4jf)
(68.0 mg,
1
0.26 mmol) was obtained in 88% yield as a colorless oil; H NMR
(400 MHz, CDCl3): d=0.90–1.01 (m, 5H), 1.27–1.42 (m, 8H), 1.43 (s,
3H), 1.51 (br, 1H), 2.02–2.09 (m, 2H), 5.46 (dt, J=16.0, 6.4 Hz, 1H),
6.26 (d, J=16.0 Hz, 1H), 7.10–7.14 (m, 1H), 7.19–7.23 (m, 2H),
7.34–7.37 ppm (m, 2H); 13C NMR (100 MHz, CDCl3): d=14.1, 20.3,
21.8, 21.9, 25.6, 26.4, 31.9 (2 carbons overlapped), 50.6, 75.0, 125.8,
127.4, 128.8, 131.7, 134.1, 145.7 ppm; IR (neat): n˜ =3567, 2932,
2857, 1685, 1597, 1493, 1444, 1375, 1258, 1127, 1027, 967, 925,
843, 790, 710 cmÀ1; HRMS (ESI-TOF) m/z calcd. C18H26NaO 281.1881
[M+Na+]; found: 281.1886.
(E)-1,1-Dicyclopropyl-2-ethyl-4-phenylpent-3-en-1-ol (5jk) (21.9 mg,
1
0.08 mmol) was obtained in 27% yield as a colorless oil; H NMR
(400 MHz, CDCl3): d=0.18–0.47 (m, 8H), 0.73–0.79 (m, 1H), 0.82 (t,
J=7.8 Hz, 3H), 0.94–1.01 (m, 2H), 1.32–1.43 (m, 1H), 1.85–1.94 (m,
1H), 2.02 (s, 3H), 2.52–2.58 (m, 1H), 5.69 (d, J=10.6 Hz, 1H), 7.15–
7.17 (m, 1H), 7.23–7.28 (m, 2H), 7.32–7.35 ppm (m, 2H); 13C NMR
(100 MHz, CDCl3): d=À0.69, 0.37, 1.00, 1.64, 12.8, 16.0, 16.6, 17.5,
23.1, 53.3, 72.6, 125.7, 126.7, 128.2, 129.8, 137.7, 144.0 ppm; IR
(neat): n˜ =3586, 3006, 2961, 2928, 2870, 1654, 1560, 1542, 1509,
1491, 1458, 1379, 1261, 1020, 911, 799, 758, 696 cmÀ1; HRMS (ESI-
TOF) m/z calcd. C19H26NaO 293.1881 [M+Na+]; found: 293.1878.
(E)-2,2-Dimethyl-5-(2-phenylhex-3-en-2-yl)-1,3-dioxan-5-ol
(4jg)
(71.8 mg, 0.23 mmol) was obtained in 78% yield as a colorless oil;
1H NMR (400 MHz, CDCl3): d=0.96 (t, J=7.3 Hz, 3H), 1.27 (s, 3H),
1.30 (s, 3H), 1.45 (s, 3H), 2.04–2.12 (m, 2H), 3.09 (s, 1H), 3.27–3.35
(m, 2H), 3.85 (d, J=11.9 Hz, 1H), 3.93 (d, J=11.9 Hz, 1H), 5.52 (dt,
J=16.0, 6.4 Hz, 1H), 6.11 (d, J=16.0 Hz, 1H), 7.10–7.15 (m, 1H),
7.18–7.22 (m, 2H), 7.41–7.44 ppm (m, 2H); 13C NMR (100 MHz,
CDCl3): d=13.9, 18.3, 20.4, 26.1, 28.5, 46.8, 65.7, 66.0, 70.6, 97.9,
126.3, 127.5, 128.4, 132.1, 132.5, 144.2 ppm; IR (neat): n˜ =3482,
3090, 3055, 2987, 2874, 1654, 1599, 1494, 1445, 1372, 1255, 1226,
1201, 1154, 1087, 1054, 1031, 991, 931, 834, 810, 759, 733,
701 cmÀ1; HRMS (ESI-TOF) m/z calcd. C18H26NaO3 313.1780 [M+Na+
]; found: 313.1784.
(E)-2-Hydroxy-2-phenylhept-4-en-3-one (6ic) (11.6 mg, 0.05 mmol)
was obtained in 19% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3): d=0.92 (t, J=7.3 Hz, 3H), 1.70 (s, 3H), 2.06–2.14 (m, 2H),
4.71 (s, 1H), 6.11 (d, J=15.1 Hz, 1H), 7.05 (dt, J=15.1, 6.9 Hz, 1H),
7.21–7.38 ppm (m, 5H); 13C NMR (100 MHz, CDCl3): d=12.1, 24.0,
25.8, 78.6, 121.7, 126.3, 128.0, 128.6, 141.4, 152.5, 199.6 ppm; IR
(neat): n˜ =3447, 2970, 2933, 1685, 1624, 1492, 1447, 1367, 1287,
1220, 1139, 1067, 1007, 978, 914, 861, 760, 699 cmÀ1; HRMS (ESI-
TOF) m/z calcd. C13H16NaO2 227.1048 [M+Na+]; found: 227.1052.
(E)-3-Ethyl-4-methyl-4-phenyloct-5-en-3-ol
(4jh)
(28.2 mg,
0.11 mmol) was obtained in 38% yield as a colorless oil; 1H NMR
(400 MHz, CDCl3): d=0.72 (t, J=7.8 Hz, 3H), 0.75 (t, J=7.4 Hz, 3H),
0.93 (t, J=7.3 Hz, 3H), 1.32–1.44 (m, 2H), 1.45 (s, 3H), 1.47–1.61 (m,
3H), 2.00–2.08 (m, 2H), 5.43 (dt, J=15.6, 6.9 Hz, 1H), 6.25 (d, J=
15.6 Hz, 1H), 7.10–7.14 (m, 1H), 7.19–7.23 (m, 2H), 7.38–7.41 ppm
(m, 2H); 13C NMR (100 MHz, CDCl3): d=9.1, 9.2, 13.9, 21.2, 26.3,
27.7, 27.8, 51.4, 77.2, 125.9, 127.5, 128.6, 130.9, 134.9, 146.5 ppm;
IR (neat): n˜ =3586, 2963, 1654, 1597, 1542, 1491, 1458, 1376, 1260,
(E)-2-Methyl-1,2-diphenylhex-3-en-1-one (7) (33.1 mg, 0.12 mmol)
was obtained in 42% yield as a colorless oil; 1H NMR (400 MHz,
CDCl3): d=0.88 (t, J=7.3 Hz, 3H), 1.56 (s, 3H), 1.97–2.05 (m, 2H),
5.55 (dt, J=15.6, 6.4 Hz, 1H), 5.87 (d, J=15.6 Hz, 1H), 7.12–7.30 (m,
8H), 7.46–7.48 ppm (m, 2H); 13C NMR (100 MHz, CDCl3): d=13.7,
26.1, 27.2, 57.6, 126.4, 126.7, 127.8, 128.9, 130.1, 131.5, 131.7, 134.6,
136.2, 145.4, 201.1 ppm; IR (neat): n˜ =3024, 2964, 2931, 1678, 1596,
1577, 1491, 1446, 1371, 1232, 1181, 1076, 1027, 972, 909, 853, 763,
700 cmÀ1; HRMS (ESI-TOF) m/z calcd. C19H20NaO 287.1412 [M+
Na+]; found: 287.1421.
1121, 1028, 960, 761, 702 cmÀ1
; HRMS (ESI-TOF) m/z calcd.
C17H26NaO 269.1881 [M+Na+]; found: 269.1877.
(E)-3,4-Diethyl-6-phenylhept-5-en-3-ol (5jh) (15.3 mg, 0.06 mmol)
1
was obtained in 21% yield; colorless oil; H NMR (400 MHz, CDCl3):
Synthesis of Substrate
d=0.78–0.85 (m, 9H), 1.17–1.27 (m, 2H), 1.44–1.47 (m, 3H), 1.54–
1.65 (m, 2H), 2.01 (s, 3H), 2.42–2.48 (m, 1H), 5.59 (d, J=10.5 Hz,
1H), 7.15–7.19 (m, 1H), 7.23–7.27 (m, 2H), 7.33–7.35 ppm (m, 2H);
13C NMR (100 MHz, CDCl3): d=7.6, 7.8, 12.7, 16.7, 22.4, 28.6, 28.8,
47.5, 76.8, 125.8, 126.8, 128.2, 129.1, 137.6, 144.0 ppm; IR (neat):
n˜ =3586, 2965, 1654, 1560, 1542, 1508, 1491, 1458, 1379, 948, 756,
Cyclopropenes were synthesized from ketones in 4 steps.[20]
1-Methyl-2-(1-phenylcycloprop-2-en-1-yl)benzene (1g) (185 mg,
0.9 mmol) was obtained in 6% yield (4 steps) as a colorless oil;
1H NMR (400 MHz, CDCl3): d=2.10 (s, 3H), 6.88–6.91 (m, 2H), 7.03–
7.21 (m, 7H), 7.45 ppm (s, 2H); 13C NMR (100 MHz, CDCl3): d=19.4,
Chem. Asian J. 2016, 11, 713 – 721
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Full Paper
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30.8, 113.6, 125.1, 126.3, 126.6 (2 carbons overlapped), 127.8, 129.1,
130.4, 137.2, 144.1, 148.1 ppm; IR (neat): n˜ =3567, 2923, 1638,
1598, 1542, 1509, 1490, 1445, 1136, 902, 749, 728, 698 cmÀ1; HRMS
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1-Fluoro-4-(1-phenylcycloprop-2-en-1-yl)benzene (1h) (506 mg,
2.4 mmol) was obtained in 32% yield (4 steps) as a colorless oil;
1H NMR (400 MHz, CDCl3): d=6.99–7.06 (m, 2H), 7.18–7.28 (m, 5H),
7.33–7.37 (m, 2H), 7.52 (s, 1H), 7.53 ppm (s, 1H); 13C NMR
(100 MHz, CDCl3): d=31.2, 113.3, 114.8 (d, J=21.0 Hz), 125.8, 127.9,
128.1, 129.5 (d, J=7.6 Hz), 142.7, 146.9, 161.1 ppm (d, J=243 Hz);
19F NMR (376 MHz, CDCl3): d=À117.23 ppm; IR (neat): n˜ =3100,
3056, 3023, 2926, 1892, 1640, 1599, 1507, 1491, 1445, 1224, 1157,
1094, 1074, 1014, 992, 900, 854, 810, 754, 700, 671 cmÀ1; HRMS
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1,1’-(cycloprop-2-ene-1,1-diyl)bis(benzene-2,3,4,5,6-d5)
(d-1a)
(933 mg, 4.6 mmol) was obtained in 46% yield (4 steps) as a color-
less oil; H NMR (400 MHz, CDCl3): d=7.55 ppm (s, 2H); 13C NMR
(100 MHz, CDCl3): d=31.6, 113.2, 125.2 (t, J=24.8 Hz), 127.5 (t, J=
23.8 Hz), 127.6 (t, J=22.9 Hz), 146.9 ppm; IR (neat): n˜ =3134, 3098,
2926, 2273, 1640, 1566, 1437, 1369, 1281, 1206, 1063, 991, 901,
862, 823, 751 cmÀ1; HRMS (ESI-TOF) m/z calcd. C15H3D10 203.1645
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Acknowledgements
This work was supported by JST PRESTO program and Grant-
in-Aid for Scientific Research (B).
Keywords: allylation · carbenoids · silver · zinc
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Manuscript received: October 7, 2015
Accepted Article published: November 27, 2015
Final Article published: January 13, 2016
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