Cationic Palladium(II)-Catalyzed Reductive Cyclization of Alkynyl Cyclohexadienones

Article abstract of DOI:10.1021/acs.joc.7b02641

A cationic palladium(II)-catalyzed reductive cyclization of cyclohexadienone-containing 1,6-enynes by using ethanol as a hydrogen donor and solvent was successfully developed. This procedure offers convenient access to cyclohexenone-annulated heterocycles under mild reaction conditions. The reaction was initiated by hydropalladation of the alkyne and was quenched by addition of the intramolecular conjugate alkene. This possible mechanism was preliminarily demonstrated by deuterium-labeling experiments.

Full text of DOI:10.1021/acs.joc.7b02641

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Note
Cationic Palladium(II)-Catalyzed Reductive
Cyclization of Alkynyl Cyclohexadienones
Weiming Wu, tianyu chen, Junjie Chen, and Xiuling Han
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.7b02641 • Publication Date (Web): 20 Dec 2017
Downloaded from http://pubs.acs.org on December 21, 2017
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Cationic Palladium(II)-Catalyzed Reductive Cyclization of Alkynyl
Cyclohexadienones
a
a,b
b
,b
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Weiming Wu, Tianyu Chen, Junjie Chen, and Xiuling Han*
a
School of Metallurgy and Chemical Engineering, Jiangxi University of Science and
Technology, Ganzhou 341000, China
b
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic
Chemistry, University of Chinese Academy of Sciences, Chinese Academy of
Sciences, 345 Lingling Road, Shanghai 200032, China
ABSTRACT:
A
cationic
palladium(II)-catalyzed
reductive
cyclization
of
cyclohexadienone-containing 1,6-enynes by using ethanol as a hydrogen donor and
solvent was successfully developed. This procedure offered a convenient access to
cyclohexenone-annulated heterocycles under mild reaction conditions. The reaction is
initiated by hydropalladation of alkyne and quenched by addition to the
intramolecular conjugate alkene and this possible mechanism was preliminarily
demonstrated by deuterium-labeling experiments.
Transition-metal-catalyzed cyclization reactions of enynes have emerged as useful
1
methods for efficient synthesis of functionalized cyclic and heterocyclic compounds.
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In the past two decades, the cyclization of cyclohexadienone-containing 1,6-enynes
with different nucleophiles catalyzed by transition-metals provided versatile way for
the access of cyclohexenone-annulated systems in a highly selective, atom- and
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step-economical manner. The nucleophiles include acetic acid, arylboronic acids,
5
6
bis(pinacolato)diboron and N-pivaloxloxy(or methoxy)-benzamides. In 2013, Ding
7
8
group employed a palladium(0)-catalyzed reductive cyclization (developed by Trost )
of cyclohexadienone-containing 1,6-enynes for the total synthesis of indoxamycins,
where Et SiH and HOAc served as the hydrogen donors.
3
Our group has been involved in the development of palladium(II)-catalyzed
9
redox-neutral reactions. Very recently, we reported intramolecular reductive
cyclization reactions of alkyne-tethered ketones or aldehydes by using ethanol as the
1
0
hydrogen source and solvent. These reactions are initiated by hydropalladation of
alkynes and quenched by addition to the carbonyl groups. Based on these previous
work, we envisioned that a reductive cyclization of 1,6-enynes catalyzed by
palladium(II) complex may be realized by using ethanol as the hydrogen source. In
the literature, although there are some transition-metal catalyzed examples for this
11
kind of reductive cyclization, the hydrogen source usually comes from H2,
8
,12
13
hydrosilanes or organozinc reagents. In 2007, Cheng reported a cobalt-catalyzed
reductive cyclization of 1,6-enynes by using water as the hydrogen source. However,
14
equivalents of Zn and a catalytic amount of ZnI should be added in the system.
2
Therefore, the use of ethanol is undoubtedly an environmentally benign and
1
5
economical strategy. Herein, we report a mild and stereoselective reductive
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cyclization of cyclohexadienone-containing 1,6-enynes catalyzed by cationic
palladium complex using ethanol as the hydrogen donor and solvent.
Initially, alkynyl cyclohexadienone 1a was selected as the model substrate to screen
the reaction conditions (Table 1). In our previous work on reductive cyclization
reactions, it was found that cationic palladium complexes can give good results.
Therefore, we focused on employing some cationic palladium complexes in the
evaluation of reaction of 1a in ethanol. It was pleased to see that the cyclization can
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be realized to give product 2a smoothly at 40 C when the catalysts bearing
1
6
diphosphine ligand such as dppp, dppb and dppe were used (entries 1-4) . Among
which, [(dppp)Pd(H O) ](BF ) gave the best yield (76%). In contrast,
2
2
4 2
[(bpy)Pd(H O) ](BF ) has no catalytic activity for the procedure (entry 5). When the
2
2
4 2
reaction was conducted in dioxane (no ethanol), no reaction occurred, which showed
that ethanol is important for the cyclization (entry 6). Lowering the temperature to
room temperature increased the yield of 2a to 85% (entry 7). Addition of the
cosolvent such as dioxane, DCE, THF and toluene did not improve the cyclization,
which only gave lower yields (entries 8-11). Further investigation showed that no
reaction occurred without the catalyst (entry 12). From the series of detailed screening
mentioned above, the combination of 1.0 equiv of 1a and 5 mol % of
[(dppp)Pd(H O) ](BF ) in ethanol at room temperature overnight was determined as
2
2
4 2
the optimum reaction conditions for our new procedure.
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Table 1. Screening the Reaction Conditions for the Reductive Cyclization of 1a
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II
o
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entry
Pd catalyst
cosolvent
T ( C)
2a (%)
76
1
2
3
4
5
[(dppp)Pd(H O) ](BF )
4 2
-
40
40
40
40
40
40
rt
2
2
[(dppp)Pd(H O) ](OTf)
2
-
54
2
2
[(dppb)Pd(H O) ](BF )
4 2
-
56
2
2
[(dppe)Pd(H O) ](OTf)
2
-
-
18
2
2
[(bpy)Pd(H O) ](BF )
4 2
trace
nr
2
2
c
6
[(dppp)Pd(H O) ](BF )
4 2
dioxane
-
2
2
d
7
8
9
[(dppp)Pd(H O) ](BF )
4 2
85 (85)
79
2
2
[(dppp)Pd(H O) ](BF )
4 2
dioxane
DCE
THF
toluene
-
rt
2
2
[(dppp)Pd(H O) ](BF )
4 2
rt
72
2
2
1
0
1
[(dppp)Pd(H O) ](BF )
4 2
rt
68
2
2
1
[(dppp)Pd(H O) ](BF )
4 2
rt
54
2
2
12
-
rt
nr
a
Reaction conditions: 1a (0.1 mmol, 1.0 equiv) and catalyst (5 mol %) were added to
ethanol (1 mL)/cosolvent (0.2 mL) as shown in the table, the mixture was then stirred
o
b
at 40 C for 5 h (or room temperature overnight). The yield was determined by
1
C
HNMR analysis using 1,3,5-trimethoxybenzene as an internal standard. Without
d
ethanol.
The yield in parentheses was isolated yield, dppp
=
1
,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, dppe
=
1,2-bis(diphenylphosphino)ethane, bpy = bipyridine, rt = room temperature, nr =
no reaction.
To investigate the generality and the scope of this reductive cyclization, various
cyclohexadienone-containing 1,6-enynes were subjected to the above-mentioned
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optimum conditions and the result was summarized in Table 2. Firstly, the substituent
effect on cyclohexadienone skeleton was examined. Substrates with alkyl groups
1
involved methyl, ethyl and n-butyl (R ) furnished the corresponding products in
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moderate to good yields (2a, 2b and 2c). When R was a phenyl or substituted phenyl
group, the reaction also proceeded successfully to give the desired cyclization
products and the result showed that chloro, fluoro and trifluoromethyl groups were
compatible with the procedure (2d-2i). Notably, the reaction was amenable with a
naphthyl group on the cyclohexadienone skeleton (2j). Then, the influence of
substituent on the alkyne was investigated. It was found that TBS
(tert-butyldimethylsilyl), DMPS (dimethylphenylsilyl) and TES (triethylsilyl)
provided the products in lower yields than TMS (trimethylsilyl), which may be due to
the steric hinderance (2k, 2l and 2m). Substrate with methyl group on the alkyne
produced 2n in 69% yield and the substrate bearing tertiary butyl group only gave
product 2o in 51% yield. When a phenyl group was substituted on the alkyne, the
reaction was disordered with the formation of unidentified products (2p). No reaction
occurred for the substrates bearing a terminal alkyne or with oxygen and N-Boc
tethered (2q, 2r and 2s).
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a,b
Table 2. Substrate Scope
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a
Reaction conditions: 1 (0.1 mmol, 1.0 equiv) and [(dppp)Pd(H O) ](BF ) (5 mol %)
2
2
4 2
were added to ethanol (1.2 mL), the mixture was then stirred at room temperature
b
C
overnight. Isolated yields of chromatographically pure products. nd = not
determined.
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To gain insight into the reaction mechanism, the reaction of 1a in deuterated
ethanol in the standard conditions was carried out. The use of CH CH OD as a
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hydrogen source and solvent formed product d-2a with the deuterium on
cyclohexenone ring in 71% yield (Scheme 1, equation 1). On the other hand, the use
of CH CD OH afforded d-2a’ deuterated at the exocyclic double bond in 64% yield
3
2
(
Scheme 1, equation 2).
Scheme 1. Deuterium-Labeling Experiments
On the basis of the above result and according to our previous work, a proposed
catalytic cycle for this novel cationic palladium(II)-catalyzed reductive cyclization of
1
,6-enyne is illustrated in Scheme 2. The active catalytic species A is initially formed
from the pre-catalyst [(dppp)Pd(H O) ](BF ) , which then reacts with ethanol to
2
2
4 2
generate Pd ethoxide complex B. -H elimination of B produces the key intermediate
Pd hydride complex C. Insertion of the carbon-carbon triple bond in substrate 1a into
hydrogen-palladium bond in intermediate C affords a vinylpalladium intermediate D.
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Addition of the carbon-palladium bond to the intramolecular conjugate alkene gives
rise to intermediate E or enolate E’. Protonolysis of E or E’ by ethanol delivers
product 2a and regenerates palladium(II) species to complete the catalytic cycle. From
deuterium-labeling studies, it is obvious to see that the hydrogen in exocyclic double
bond comes from the -H in ethanol and OH provides the hydrogen source in
protonolysis step, which is different from the rhodium-catalyzed reductive cyclization
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of 1,6-enyne using ethanol as the hydrogen source.
Scheme 2. A Proposed Catalytic Cycle
To demonstrate the synthetic utility of the present reaction, we transformed product
2
a, as summarized in Scheme 3. The TMS group can be easily substituted by iodine
atom to give product 3a in 74% yield when treatment of 2a with N-iodosuccinimide in
acetonitrile. In addition, 3a can be further transferred to compound 4a via
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Sonogashira coupling.
Scheme 3. Transformations of Product 2a
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In conclusion, we have developed a cationic palladium(II)-catalyzed reductive
cyclization of cyclohexadienone-containing 1,6-enynes to give access to fused
heterocycles under mild reaction conditions by using ethanol as a hydrogen donor and
solvent. This is the first example by using ethanol as the hydrogen source in
palladium-catalyzed enyne cyclization. The reaction is initiated by hydropalladation
of alkyne and quenched by addition to the intramolecular conjugate alkene and this
possible mechanism was preliminarily demonstrated by deuterium-labeling
experiments. Studies on asymmetric version of the reaction and the application of this
methodology are currently underway in our laborotary.
EXPERIMENTAL SECTION
General Information. All solvents were dried and distilled using standard
procedures. Unless otherwise noted, reagents were obtained from commercial sources
1
13
and used without further purification. H NMR and C NMR were recorded in
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deuterated chloroform (CDCl ). Coupling constants are recorded in hertz, and
3
chemical shifts are recorded as δ values in ppm. The following abbreviations are used
to describe multiplicities: s = singlet, brs = broad singlet, d = doublet, dd = double
doublet, t = triplet, m = multiplet. High-resolution mass spectra were carried out on a
mass spectrometer with a TOF analyzer (ESI). Infrared spectra were recorded on a
FT-IR spectrometer. Melting points were determined by using a local hot-stage
melting point apparatus and are uncorrected. For column chromatography, silica gel
of 200−300 mesh size was used.
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General procedure for the preparation of substrates 1a-1q.
K CO
(4.0 mmol, 2.0 equiv) and N-oxocyclohexa-2,5-dien-1-yl-
2
3
1
7
benzenesulfonamide (2.0 mmol, 1.0 equiv) were added to 40 mL of acetonitrile and
o
the mixture was stirred at 60 C for 15 minutes. Then substituted 3-bromoprop-1-yne
(2.6 mmol, 1.3 equiv) was added and the solution was stirred until the consumption of
N-oxocyclohexa-2,5-dien-1-yl-benzenesulfonamide as monitored by TLC. The
solvent was evaporated under reduced pressure and the residue was purified by flash
chromatography (petroleum ether : ethyl acetate = 6:1 ) to give the products 1a-1o.
4
1
-Methyl-N-(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)-N-(3-(trimethylsilyl)prop-2-yn-
o
1
-yl)benzenesulfonamide (1a). white solid; (232 mg; 30% yield); m.p.: 80-82 C; H
NMR (400 MHz, CDCl ): δ 7.83 (d, J = 8.4 Hz, 2H), 7.28 (d, J = 8.0 Hz, 2H), 7.04 (d,
3
J = 10.4 Hz, 2H), 6.14 (d, J = 10.0 Hz, 2H), 4.30 (s, 2H), 2.44 (s, 3H), 1.62 (s, 3H),
1
3
1
0.14 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ 184.6, 151.6, 144.0, 138.5, 129.6,
3
-1
1
28.1, 127.8, 102.0, 91.1, 60.1, 37.2, 26.1, 21.7, -0.3; IR (neat, cm ): 2957, 1664,
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1630, 1601, 1395, 1154, 808; HRMS calculated for C H NO SSi (M+H) : 388.1397;
2
0
26
3
Found: 388.1395.
N-(1-Ethyl-4-oxocyclohexa-2,5-dien-1-yl)-4-methyl-N-(3-(trimethylsilyl)prop-2-yn-1-
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
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4
4
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5
5
5
5
5
6
0
1
2
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4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
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6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
o
1
yl)benzenesulfonamide (1b). yellow solid; (498 mg; 62% yield); m.p.: 50-52 C; H
NMR (400 MHz, CDCl ): δ 7.8 (d, J = 8.4 Hz, 2H), 7.26 (d, J = 7.6 Hz, 2H), 6.95 (d,
3
J = 10.4 Hz, 2H), 6.20 (d, J = 10.0 Hz, 2H), 4.34 (s, 2H), 2.43 (s, 3H), 2.03 (q, J = 7.6
13
1
Hz, 2H), 0.75 (t, J = 7.2 Hz, 3H), 0.14 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ
3
1
85.1, 149.5, 144.0, 138.6, 129.5, 128.2, 102.2, 91.1, 77.5, 76.8, 64.5, 37.0, 29.7, 21.7,
-1
8.6, -0.3; IR (neat, cm ):  2960, 2177, 1667, 1630, 1599, 1349, 1158, 1089, 841;
+
HRMS calculated for C H NO SSi (M+H) : 402.1554; Found: 402.1547.
2
1
28
3
N-(1-Butyl-4-oxocyclohexa-2,5-dien-1-yl)-4-methyl-N-(3-(trimethylsilyl)prop-2-yn-1-
o
1
yl)benzenesulfonamide (1c). yellow solid; (575 mg; 67% yield); m.p.: 85-88 C; H
NMR (400 MHz, CDCl ): δ 7.7 (d, J = 8.4 Hz, 2H), 7.20 (d, J = 8.0 Hz, 2H), 6.91 (d,
3
J = 10.4 Hz, 2H), 6.11 (d, J = 10.0 Hz, 2H), 4.27 (s, 2H), 2.36 (s, 3H), 1.93-1.89 (m,
2
H), 1.16-1.13 (m, 2H), 1.05-0.99 (m, 2H), 0.73 (t, J = 7.2 Hz, 3H), 0.08 (s, 9H);
1
3
1
C{ H} NMR (100 MHz, CDCl ): δ 18, 149.7, 143.8, 138.3, 129.3, 128.9, 128.0,
3
-1
1
02.0, 90.8, 63.7, 36.7, 36.3, 25.9, 22.5, 21.5, 13.7, -0.5; IR (neat, cm ): 2953, 2866,
+
1
672, 1632, 1600, 1150, 842; HRMS calculated for C H NO SSi (M+H) : 430.1867;
2
3
32
3
Found: 430.1864.
4
-Methyl-N-(4-oxo-1,4-dihydro-(1,1'-biphenyl)-1-yl)-N-(3-(trimethylsilyl)prop-2-yn-1-
o
1
yl)benzenesulfonamide (1d). yellow solid (674 mg; 75% yield); m.p.: 149-150 C; H
NMR (400 MHz, CDCl ): δ 7.74 (d, J =8.4 Hz, 2H), 7.43-7.33 (m, 7H), 7.21 (d, J =
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2
2
2
2
2
2
2
3
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3
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8.0 Hz, 2H), 6.11 (dd, J = 8.4, 1.6 Hz, 2H), 4.19 (s, 2H), 2.42 (s, 3H), 0.15 (s, 9H);
1
3
1
C{ H} NMR (100 MHz, CDCl ): δ 184.6, 147.7, 144.2, 138.0, 137.3, 129.5, 129.3,
3
-1
1
29.2, 128.6, 127.6, 126.8, 102.1, 91.0, 65.2, 37.6, 21.7, -0.3; IR (neat, cm ): 2959,
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
+
1663, 1624, 1596, 1347, 847; HRMS calculated for C H NO SSi (M+H) : 450.1554;
2
5
28
3
Found: 450.1550.
4-Methyl-N-(4'-methyl-4-oxo-1,4-dihydro-(1,1'-biphenyl)-1-yl)-N-(3-(trimethylsilyl)-
prop-2-yn-1-yl) benzenesulfonamide (1e). yellow solid; (306 mg; 33% yield); m.p.:
o
1
9
6-98 C; H NMR (400 MHz, CDCl ): δ 7.75 (d, J = 8.4 Hz, 2H), 7.40 (d, J = 10.4
3
Hz, 2H), 7.27-7.25 (m, 2H), 7.20 (d, J = 8.0 Hz, 2H), 7.14 (d, J = 8.0 Hz, 2H), 6.08
13
1
(
dd, J = 8.8, 2.0 Hz, 2H), 4.18 (s, 2H), 2.41 (s, 3H), 2.34 (s, 3H), 0.15 (s, 9H); C{ H}
NMR (100 MHz, CDCl ): δ 184.7, 147.9, 144.1, 139.4, 137.3, 134.9, 130.2, 129.2,
3
-
1
1
2
28.7, 127.4, 126.8, 102.2, 90.9, 65.0, 37.5, 21.7, 21.2, -0.3; IR (neat, cm ):2958,
924, 2251, 2177, 1668, 1629, 1599, 1398, 1159, 843;HRMS calculated for
+
C H NO SSi (M+H) : 464.1710; Found: 464.1704.
26
30
3
N-(4'-Methoxy-4-oxo-1,4-dihydro-(1,1'-biphenyl)-1-yl)-4-methyl-N-(3-(trimethylsilyl)-
prop-2-yn-1-yl)benzenesulfonamide (1f). yellow solid; (613 mg; 64% yield); m.p.:
o
1
4
6-48 C; H NMR (400 MHz, CDCl ): δ 7.7 (d, J = 7.6 Hz, 2H), 7.42 (d, J = 10.0
3
Hz, 2H), 7.30 (d, J = 8.8 Hz, 2H), 7.22 (d, J = 8.0 Hz, 2H), 6.85 (d, J = 8.4 Hz, 2H),
13
1
6.10 (d, J = 10.0 Hz, 2H), 4.19 (s, 2H), 3.79 (s, 3H), 2.42 (s, 3H), 0.17 (s, 9H); C{ H}
NMR (100 MHz, CDCl ): δ 184.5, 160.0, 147.9, 143.9, 137.2, 129.2, 129.0, 128.5,
3
-
1
1
2
28.1, 127.1, 114.6, 102.1, 90.6, 64.5, 55.3, 37.3, 21.5, -0.4; IR (neat, cm ): 2957,
901, 1667, 1629, 1602, 1506, 1157, 836; HRMS calculated for C H NO SSi
2
6
30
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(M+H) : 480.1659; Found: 480.1656.
N-(4'-Fluoro-4-oxo-1,4-dihydro-(1,1'-biphenyl)-1-yl)-4-methyl-N-(3-(trimethylsilyl)-
prop-2-yn-1-yl)benzenesulfonamide (1g). yellow solid; (613 mg; 66% yield); m.p.:
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
o
1
42-43 C; H NMR (400 MHz, CDCl ): δ 7.71 (d, J = 8.4 Hz, 2H), 7.40-7.34 (m, 4H),
3
7
.21 (d, J = 8.4 Hz, 2H), 7.01 (t, J = 8.8 Hz, 2H), 6.13 (d, J = 10.0 Hz, 2H), 4.18 (s,
1
3
1
2H), 2.42 (s, 3H), 0.16 (s, 9H); C{ H}NMR (100 MHz, CDCl ): δ 184.3, 162.9 (d, J
3
=
249.0 Hz), 147.4, 144.2, 137.3, 133.8, 129.2, 128.8 (d, J = 8.4 Hz), 128.4, 127.7,
1
9
1
16.4 (d, J = 22.0 Hz), 101.9, 91.0, 64.6, 37.6, 21.6, -0.4; F NMR (376 MHz,
-1
CDCl ): δ -111.7; IR (neat, cm ):2959, 2926, 2253, 2178, 1669, 1630, 1599, 1503,
3
+
1
398, 1344, 1185, 838; HRMS calculated for C H FNO SSi (M+H) : 468.1459;
25
27
3
Found: 468.1454.
N-(4'-Chloro-4-oxo-1,4-dihydro-(1,1'-biphenyl)-1-yl)-4-methyl-N-(3-(trimethylsilyl)-
1
prop-2-yn-1-yl)benzenesulfonamide (1h). yellow oil (455 mg; 47% yield); H NMR
(400 MHz, CDCl ): δ 7.70 (d, J = 8.4 Hz, 2H), 7.38 (d, J = 10.4 Hz, 2H), 7.31-7.27
3
(
m, 4H), 7.21 (d, J = 8.0 Hz, 2H), 6.14 (d, J = 10.0 Hz, 2H), 4.18 (s, 2H), 2.42 (s, 3H),
1
3
1
0.15 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ 184.3, 147.1, 144.3, 137.3, 136.7,
3
1
35.3, 129.5, 129.3, 128.5, 128.3, 128.0, 101.8, 91.2, 64.7, 37.7, 21.7, -0.3; IR (neat,
-1
cm ): 2959, 2177, 1669, 1630, 1597, 1346, 1159, 839; HRMS calculated for
+
C H ClNO SSi (M+H) : 484.1164; Found: 484.1158.
25
27
3
4
-Methyl-N-(4-oxo-4'-(trifluoromethyl)-1,4-dihydro-(1,1'-biphenyl)-1-yl)-N-(3-(tri-
methylsilyl)prop-2-yn-1-yl)benzenesulfonamide (1i). yellow solid; (538 mg; 52%
o
1
yield); m.p.: 62-64 C; H NMR (400 MHz, CDCl ): δ 7.71 (d, J = 8.0 Hz, 2H),
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2
2
2
2
2
2
2
3
3
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7.61-7.54 (m, 4H), 7.46 (d, J = 10.0 Hz, 2H), 7.25 (d, J = 8.0 Hz, 2H), 6.24 (d, J =
13
1
1
0.0 Hz, 2H), 4.24 (s, 2H), 2.46 (s, 3H), 0.19 (s, 9H); C{ H} NMR (100 MHz,
CDCl ): δ 184.1, 146.7, 144.3, 142.2, 137.2, 131.1 (q, J = 32.6 Hz), 129.3, 128.4,
3
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
128.3, 127.3, 126.2 (q, J = 3.8 Hz), 123.7 (q, J = 271.0 Hz), 101.5, 91.2, 64.9, 37.9,
19
-1
2
1.6, -0.4; F NMR (376 MHz, CDCl ): δ -62.8; IR (neat, cm ):2960, 1671, 1613,
3
+
1324, 1160, 840; HRMS calculated for C H F N O SSi (M+NH ) : 535.1693;
2
6
30
3
2
3
4
Found: 535.1696.
-Methyl-N-(1-(naphthalen-2-yl)-4-oxocyclohexa-2,5-dien-1-yl)-N-(3-(trimethylsilyl)-
prop-2-yn-1-yl)benzenesulfonamide (1j). yellow solid; (709 mg; 71% yield); m.p.:
4
o
1
7
1-73 C; H NMR (400 MHz, CDCl ): δ 7.85-7.81 (m, 2H), 7.76-7.72 (m, 4H),
3
7.57-7.49 (m, 5H), 7.17 (d, J = 8.0 Hz, 2H), 6.17 (d, J = 9.6 Hz, 2H), 4.22 (s, 2H),
1
3
1
2
1
.40 (s, 3H), 0.16 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ 164.6, 147.5, 144.1,
3
37.2, 135.0, 133.2, 133.1, 129.4, 129.1, 128.6, 128.2, 127.7, 127.2, 126.9, 125.9,
-1
124.1, 102.0, 90.9, 65.1, 37.6, 21.6, -0.4; IR (neat, cm ):3055, 2958, 1735, 1668,
+
1
630, 1597, 1342, 1158, 841; HRMS calculated for C H NO SSi (M+H) : 500.1710;
2
9
30
3
Found: 500.1705.
N-(3-(tert-Butyldimethylsilyl)prop-2-yn-1-yl)-4-methyl-N-(1-methyl-4-oxocyclohexa-
,5-dien-1-yl)benzenesulfonamide (1k). yellow solid; (317 mg; 37% yield); m.p.:
2
o
1
108-110 C; H NMR (400 MHz, CDCl ): δ 7.83 (d, J = 8.4 Hz, 2H), 7.28 (d, J = 8.0
3
Hz, 2H), 7.06 (d, J = 10.0 Hz, 2H), 6.14 (d, J = 10.4 Hz, 2H), 4.32 (s, 2H), 2.43 (s,
1
3
1
3H), 1.61 (s, 3H), 0.91 (s, 9H) , 0.08 (s, 6H); C{ H} NMR (100 MHz, CDCl ): δ
3
1
84.6, 151.6, 144.0, 138.6, 129.7, 128.0, 127.8, 102.8, 89.4, 60.1, 37.2, 26.1, 26.0,
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21.7, 16.6, -4.7; IR (neat,cm ):2947, 2927, 2853, 1671, 1630, 1318, 1150, 862;
+
HRMS calculated for C H NO SSi (M+H) : 430.1867; Found: 430.1861.
2
3
32
3
N-(3-(Dimethyl(phenyl)silyl)prop-2-yn-1-yl)-4-methyl-N-(1-methyl-4-oxocyclohexa-2,
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
5-dien-1-yl)benzenesulfonamide (1l). white solid; (334 mg; 37% yield); m.p.: 85-87
o
1
C; H NMR (400 MHz, CDCl ): δ 7.78 (d, J = 8.4 Hz, 2H), 7.52 (d, J = 7.6 Hz, 2H),
3
7.42-7.36 (m, 3H), 7.15 (d, J = 7.6 Hz, 2H), 6.99 (d, J = 10.4 Hz, 2H), 6.07 (d, J =
13
1
1
0.0 Hz, 2H), 4.36 (s, 2H), 2.38 (s, 3H), 1.59 (s, 3H) , 0.39 (s, 6H); C{ H} NMR
(
100 MHz, CDCl ): δ 184.5, 151.6, 144.0, 138.2, 136.0, 133.6, 129.8, 129.5, 128.1,
3
-1
128.0, 127.7, 103.5, 89.3, 60.0, 37.2, 26.1, 21.6, -1.3; IR (neat, cm ):3048, 2965,
+
1
664, 1630, 1600, 1154, 811; HRMS calculated for C H NO SSi (M+H) : 450.1554;
2
5
28
3
Found: 450.1563.
4
-Methyl-N-(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)-N-(3-(triethylsilyl)prop-2-yn-1-
o
1
yl)benzenesulfonamide (1m). yellow solid; (275 mg; 32% yield); m.p.: 72-73 C; H
NMR (400 MHz, CDCl ): δ 7.82 (d, J = 8.4 Hz, 2H), 7.28 (d, J = 8.4 Hz, 2H), 7.07 (d,
3
J = 9.6 Hz, 2H), 6.13 (d, J = 10.0 Hz, 2H), 4.34 (s, 2H), 2.43 (s, 3H), 1.63 (s, 3H),
13
1
0.96 (t, J = 8.0 Hz, 9H), 0.57 (q, J = 8.0 Hz, 6H); C{ H} NMR (100 MHz, CDCl ):
3
δ 184.4, 151.6, 143.9, 138.4, 129.5, 127.9, 127.6, 102.9, 88.5, 60.0, 37.1, 25.9, 21.5,
-1
7
.4, 4.1; IR (neat, cm ):3045, 2876, 1703, 1665, 1630, 1600, 1329, 1155,
+
869;HRMS calculated for C H NO SSi (M+H) : 430.1867; Found: 430.1870.
2
3
32
3
N-(But-2-yn-1-yl)-4-methyl-N-(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)benzenesul-
3
b
o
1
fonamide (1n). white solid; (355 mg; 54% yield); m.p.: 96-98 C; H NMR (400
MHz, CDCl ): δ 7.79 (d, J = 8.4 Hz, 2H), 7.29 (d, J = 8.4 Hz, 2H), 7.03 (d, J = 10.0
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2
2
2
2
2
2
2
2
2
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3
3
3
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Hz, 2H), 6.14 (d, J = 10.0 Hz, 2H), 4.23 (d, J = 2.0 Hz, 2H), 2.43 (s, 3H), 1.77 (s, 3H),
1
3
1
1
.61 (s, 3H); C{ H} NMR (100 MHz, CDCl ): δ 184.6, 151.8, 143.9, 138.4, 129.4,
3
-1
1
27.9, 127.6, 81.8, 75.5, 59.8, 36.8, 26.2, 21.6, 3.5; IR (neat, cm ):3009, 2926,
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
+
1664, 1629, 1599, 1328, 1153, 812; HRMS calculated for C H NO S (M+H) :
1
8
20
3
3
30.1158; Found: 330.1158.
N-(4,4-Dimethylpent-2-yn-1-yl)-4-methyl-N-(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)-
o
1
benzenesulfonamide (1o). white solid; (613 mg; 83% yield); m.p.: 46-48 C; H NMR
(
400 MHz, CDCl ): δ 7.82 (d, J = 7.6 Hz, 2H), 7.28 (d, J = 8.0 Hz, 2H), 7.05 (d, J =
3
9.6 Hz, 2H), 6.13 (d, J = 9.6 Hz, 2H), 4.30 (s, 2H), 2.43 (s, 3H), 1.62 (s, 3H), 1.15 (s,
13
1
9
H); C{ H} NMR (100 MHz, CDCl ): δ 184.6, 152.0, 143.8, 138.4, 129.4, 128.0,
3
-1
127.4, 127.3, 94.2, 75.0, 59.8, 36.7, 30.6, 27.4, 26.1, 21.6; IR (neat, cm ): 2968,
+
1
3
709, 1671, 1631, 1601, 1150, 809;HRMS calculated for C H NO S (M+H) :
2
1
26
3
72.1628; Found: 372.1626.
4-Methyl-N-(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)-N-(3-phenylprop-2-yn-1-yl)ben-
o
1
zenesulfonamide (1p). white solid; (563 mg; 72% yield); m.p.: 96-97 C; H NMR
(400 MHz, CDCl ): δ 7.85 (d, J = 8.4 Hz, 2H), 7.36-7.25 (m, 7H), 7.07 (d, J = 10.0
3
1
3
1
Hz, 2H), 6.17 (d, J = 10.4 Hz, 2H), 4.52 (s, 2H), 2.40 (s, 3H), 1.66 (s, 3H); C{ H}
NMR (100 MHz, CDCl ): δ 184.5, 151.6, 144.0, 138.2, 131.5, 129.6, 128.8, 128.4,
3
-1
127.9, 127.7, 122.0, 85.5, 85.4, 60.0, 37.2, 26.2, 21.5; IR (neat, cm ): 3045, 1706,
+
1
668, 1319, 1150, 1088; HRMS calculated for C H NO S (M+H) : 392.1315;
2
3
22
3
Found: 392.1316.
4
-Methyl-N-(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)-N-(prop-2-yn-1-yl)benzenesul-
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o
1
fonamide (1q). white solid; (472 mg; 75% yield); m.p.: 112-114 C; H NMR (400
MHz, CDCl ): δ 7.81 (d, J = 8.0 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 7.05 (d, J = 10.4
3
Hz, 2H), 6.17 (d, J = 10.0 Hz, 2H), 4.28 (d, J = 2.4 Hz, 2H), 2.45 (s, 3H), 2.40 (s, 1H),
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
3
1
1.62 (s, 3H); C{ H} NMR (100 MHz, CDCl ): δ 184.4, 151.3, 144.1, 138.4, 129.6,
3
-1
1
28.0, 127.8, 80.3, 73.9, 60.1, 36.3, 25.8, 21.6; IR (neat, cm ): 3311, 3222, 1714,
+
1670, 1312, 1149, 815; HRMS calculated for C H NO S (M+H) : 316.1002; Found:
17
18
3
3
16.0997.
3
a
5
Substrates 1r and 1s were the known compounds and they were prepared
according to the reported procedures.
o
4
-(But-2-yn-1-yloxy)-4-methylcyclohexa-2,5-dienone (1r). white solid; m.p.: 68-70 C;
1
H NMR (400 MHz, CDCl ): δ 6.84 (d, J = 10.0 Hz, 2H), 6.30 (d, J = 10.0 Hz, 2H),
3
1
3
1
3
.96 (d, J = 2.4 Hz, 2H), 1.85 (t, J = 2.4 Hz, 3H), 1.48 (s, 3H); C{ H} NMR (100
-1
MHz, CDCl ): δ 185.1, 151.1, 130.4, 83.4, 75.6, 73.0, 54.4, 26.5, 3.8; IR (neat, cm ):
3
, 2926, 2865, 1664, 1629, 1379, 1078, 1030, 862; HRMS calculated for
+
C H O (M+H) : 177.0910; Found:177.0910.
11
13
2
tert-Butyl but-2-yn-1-yl(1-methyl-4-oxocyclohexa-2,5-dien-1-yl)carbamate (1s). oil;
1
H NMR (400 MHz, CDCl ): δ 7.07 (d, J = 10.0 Hz, 2H), 6.16 (d, J = 10.0 Hz, 2H),
3
1
3
1
4
.17 (d, J = 2.4 Hz, 2H), 1.84 (t, J = 2.4 Hz, 3H), 1.69 (s, 3H), 1.38 (s, 9H); C{ H}
NMR (100 MHz, CDCl ): δ 185.4, 155.0, 154.1, 126.7, 81.8, 79.6, 76.1, 57.5, 34.4,
3
-1
2
8.2, 26.2, 3.7; IR (neat, cm ): , 2923, 1692, 1665, 1627, 1364, 1157, 852;
+
HRMS calculated for C H NO (M+H) : 276.1594; Found:276.1594.
1
6
22
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General procedure for cationic palladium(II)-catalyzed reductive cyclization of
alkynyl cyclohexadienones. To an oven-dried Schlenk tube were added alkynyl
cyclohexadienone 1 (0.1 mmol), [(dppp)Pd(H O) ](BF ) (3.6 mg, 0.005 mmol, 5
2
2
4 2
0
1
2
3
4
5
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7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
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3
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9
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9
0
mol %) and 1.2 mL of ethanol. The resulting mixture was stirred at room temperature
overnight. Then the solvent was evaporated under reduced pressure and the residue
was purified by flash column chromatography (petroleum ether : ethyl acetate = 4:1)
to give product 2.
(Z)-7a-Methyl-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H-indol-5(7-
o
1
aH)-one (2a). white solid; (33 mg; 85% yield); m.p.: 98-100 C; H NMR (400 MHz,
CDCl ): δ 7.74 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 8.0 Hz, 2H), 6.95 (d, J = 10.4 Hz, 1H),
3
5.82 (d, J = 10.4 Hz, 1H), 5.46 (s, 1H), 4.06 (s, 2H), 2.87 (brs, 1H), 2.66 (dd, J = 16.8,
4
.0 Hz, 1H), 2.54 (dd, J = 17.2, 5.6 Hz, 1H), 2.42 (s, 3H), 1.68 (s, 3H), 0.04 (s, 9H);
1
3
1
C{ H} NMR (100 MHz, CDCl ): δ 196.0, 150.1, 149.6, 143.8, 138.4, 129.9, 128.3,
3
-1
127.0, 122.2, 64.9, 52.7, 52.0, 36.7, 23.8, 21.6, -0.7; IR (neat, cm ): 2953, 2869,
+
1
691, 1641, 1598, 836, 814; HRMS calculated for C H N O SSi (M+NH ) :
2
0
31
2
3
4
407.1819; Found: 407.1816.
(Z)-7a-Ethyl-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H-indol-5-
1
(
7aH)-one (2b). yellow oil; (23 mg; 57% yield); H NMR (400 MHz, CDCl ): δ 7.73
3
(d, J = 8.4 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 7.07 (d, J = 10.4 Hz, 1H), 5.93 (d, J =
0.0 Hz, 1H), 5.48 (s, 1H), 4.01 (s, 2H), 3.07 (t, J = 5.2 Hz, 1H), 2.44 (d, J = 6.0 Hz,
2H), 2.43 (s, 3H), 2.23 (q, J = 7.2 Hz, 1H), 1.93 (q, J = 7.6 Hz, 1H), 0.98 (t, J = 7.6
1
1
3
1
Hz, 3H), 0.05 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ 196.7, 150.8, 148.8, 143.9,
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137.4, 129.8, 129.2, 127.3, 122.5, 68.5, 51.8, 48.8, 37.9, 29.5, 21.7, 8.9, -0.6; IR (neat,
-1
cm ):2955, 2925, 1687, 1639, 1597, 1158, 836; HRMS calculated for
+
C H N O SSi (M+NH ) : 421.1976; Found: 421.1970.
21
33
2
3
4
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
(Z)-7a-Butyl-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H-indol-
1
5
(7aH)-one (2c). yellow oil; (29 mg; 68% yield); H NMR (400 MHz, CDCl ): δ 7.7
3
(d, J = 8.4 Hz, 2H), 7.29 (d, J = 8.4 Hz, 2H), 7.06 (d, J = 10.4 Hz, 1H), 5.90 (d, J =
1
2
0.4 Hz, 1H), 5.46 (d, J = 2.0 Hz, 1H), 4.05-3.96 (m, 2H), 3.06 (t, J = 5.6 Hz, 1H),
.43 (d, J = 6.4 Hz, 2H),(s, 3H), 2.15-2.12 (m, 1H), 1.89-1.85 (m, 1H),
1
3
1
1.35-1.25 (m, 4H), 0.88 (t, J = 6.8 Hz, 3H), 0.04 (s, 9H); C{ H} NMR (100 MHz,
CDCl ): δ 196.7, 150.8, 149.0, 143.9, 137.4, 129.8, 129.0, 127.2, 122.4, 68.1, 51.8,
3
-1
49.3, 37.9, 36.4, 26.6, 23.0, 21.7, 14.1, -0.6; IR (neat, cm ): 2955, 2866, 1688, 1639,
+
1
4
598, 1158, 836; HRMS calculated for C H N O SSi (M+NH ) : 449.2289; Found:
2
3
37
2
3
4
49.2288.
(Z)-7a-Phenyl-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H-indol-
o
1
5
(7aH)-one (2d). white solid; (37 mg; 82% yield); m.p.: 120-122 C; H NMR (400
MHz, CDCl ): δ 7.67 (d, J = 8.4 Hz, 2H), 7.61 (dd, J = 10.4 Hz, 1.6 Hz 1H),
3
7
.49-7.47 (m, 5H), 7.41 (d, J = 8.4 Hz, 2H), 6.37 (d, J = 10.4 Hz, 1H), 5.60 (dd, J =
.4, 2.0 Hz, 1H), 4.48 (dt, J = 14.0, 2.0 Hz, 1H), 4.39 (d, J = 14.0 Hz, 1H), 3.41 (brs,
4
1H), 2.74 (dd, J = 17.2, 4.0 Hz, 1H), 2.60 (s, 3H), 2.50 (dd, J = 17.2, 4.8 Hz, 1H),
13
1
0
.26 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ 196.4, 150.1, 147.3, 143.8, 139.9,
3
137.7, 130.5, 129.6, 128.5, 128.3, 127.3, 126.7, 121.9, 70.9, 56.2, 52.3, 35.8, 21.7,
-1
-
0.6; IR (neat, cm ): 2955, 1688, 1638, 1599, 1336, 1153, 839;HRMS calculated
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2
2
2
2
2
2
2
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3
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3
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4
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4
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5
5
5
5
5
5
5
6
+
for C H N O SSi (M+NH ) : 469.1976; Found: 469.1970.
2
5
33
2
3
4
(
Z)-7a-(p-Tolyl)-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H-indol-
1
5
-(7aH)-one (2e). yellow oil; (26 mg; 56% yield); H NMR (400 MHz, CDCl ): δ
3
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
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4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
7.50 (d, J = 7.2 Hz, 2H), 7.42 (d, J = 10.4 Hz, 1H), 7.26-7.18 (m, 4H), 7.09 (d, J = 7.6
Hz, 2H), 6.17 (d, J = 10.4 Hz, 1H), 5.42 (s, 1H), 4.27 (d, J = 13.6 Hz, 1H), 4.19 (d, J
= 14.8 Hz, 1H), 3.22 (s, 1H), 2.56 (dd, J = 16.8, 3.2 Hz, 1H), 2.43 (s, 3H), 2.35-2.30
1
3
1
(
m, 4H), 0.08 (s, 9H); C{ H} NMR (100 MHz, CDCl ): δ 196.5, 150.2, 147.5, 143.7,
3
1
38.1, 137.7, 136.8, 130.4, 129.5, 129.2, 127.4, 126.6, 121.8, 70.8, 56.1, 52.3, 35.8,
-
1
21.7, 21.3, -0.6; IR (neat, cm ): 2954, 2924, 1688, 1638, 1598, 1383, 1336, 1156,
+
8
38;HRMS calculated for C H N O SSi (M+NH ) : 483.2132; Found: 483.2128.
2
6
35
2
3
4
(Z)-7a-(4-Methoxyphenyl)-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-
1
1
H-indol-5(7aH)-one (2f). yellow oil; (30 mg; 62% yield); H NMR (400 MHz,
CDCl ): δ 7.47 (d, J = 8.4 Hz, 2H), 7.43 (dd, J = 10.0, 2.0 Hz, 1H), 7.23-7.19 (m, 4H),
3
6.78 (d, J = 8.8 Hz, 2H), 6.16 (d, J = 10.4 Hz, 1H), 5.43 (d, J = 2 Hz, 1H), 4.28 (d, J =
1
4.4 Hz, 1H), 4.20 (d, J = 14.0 Hz, 1H), 3.81 (s, 3H), 3.22 (brs, 1H), 2.56 (dd, J =
1
3
16.8, 3.6 Hz, 1H), 2.42 (s, 3H), 2.31 (dd, J = 16.8, 4.4 Hz, 1H), 0.08 (s, 9H); C
NMR (100 MHz, CDCl ): δ 194.4, 159.4, 150.1, 147.6, 143.6, 137.9, 131.3, 130.3,
3
1
29.5, 128.1, 127.3, 121.8, 113.8, 70.4, 55.9, 55.4, 52.3, 35.8, 21.7, -0.6; IR (neat,
-1
cm ): 2955, 2920, 2851, 1690, 1648, 1606, 1511, 1332, 1152, 836, 808;HRMS
+
calculated for C H N O SSi (M+NH ) : 499.2081; Found: 499.2080.
2
6
35
2
4
4
(Z)-7a-(4-Fluorophenyl)-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H
1
-
indol-5(7aH)-one (2g). yellow oil; (38 mg; 81% yield); H NMR (400 MHz, CDCl ):
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δ 7.50 (d, J = 8.0 Hz, 2H), 7.41 (d, J = 10.4 Hz, 1H), 7.31-7.25 (m, 4H), 6.98 (t, J =
8
.8 Hz, 2H), 6.19 (d, J = 10.4 Hz, 1H), 5.44 (d, J = 2.0 Hz, 1H), 4.28 (d, J = 14.4 Hz,
H), 4.21 (d, J = 14.0 Hz, 1H), 3.20 (brs, 1H), 2.59 (dd, J = 17.2, 4.0 Hz, 1H), 2.44 (s,
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
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4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
13
3H), 2.31 (dd, J = 17.2, 4.8 Hz, 1H), 0.08 (s, 9H); C NMR (100 MHz, CDCl ): δ
3
1
96.0, 162.5 (d, J = 246.7 Hz), 149.7, 146.8, 144.0, 137.6, 135.7 (d, J = 3.8 Hz),
130.7, 129.5, 128.5 (d, J = 8.3 Hz), 127.3, 122.2, 115.5 (d, J = 21.2 Hz), 70.3, 56.2,
1
9
5
2.3, 35.7, 29.8, 21.7, -0.6; F NMR (376 MHz, CDCl ): δ -113.8; IR (neat,
3
-1
cm ):2953, 2921, 2851, 1693, 1638, 1602, 1507, 1328, 1151, 839, 809; HRMS
+
calculated for C H FN O SSi (M+NH ) : 487.1881; Found: 487.1876.
2
5
32
2
3
4
(Z)-7a-(4-Chlorophenyl)-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H
1
-indol-5(7aH)-one (2h). yellow oil; (29 mg; 60% yield); H NMR (400 MHz, CDCl ):
3
δ 7.51 (d, J = 7.2 Hz, 2H), 7.40 (d, J = 10.4 Hz, 1H), 7.27-7.26 (m, 6H), 6.19 (d, J =
1
0.0 Hz, 1H), 5.44 (s, 1H), 4.27 (d, J = 14.0 Hz, 1H), 4.19 (d, J = 14.4 Hz, 1H), 3.18
(brs, 1H), 2.58 (dd, J = 15.2, 3.2 Hz, 1H), 2.44 (s, 3H), 2.30 (dd, J = 17.2, 4.0 Hz, 1H),
13
0
.08 (s, 9H); C NMR (100 MHz, CDCl ): δ 196.0, 149.6, 146.5, 144.1, 138.6, 137.5,
3
134.3, 130.9, 129.7, 128.7, 128.1, 127.3, 122.3, 70.4, 56.1, 52.3, 35.7, 21.7, -0.6; IR
-1
(
neat, cm ): 2953, 2921, 2852, 1690, 1640, 1597, 1490, 1325, 1150, 866, 839, 805;
+
HRMS calculated for C H ClN O SSi (M+NH ) : 503.1586; Found: 503.1581.
2
5
32
2
3
4
(Z)-1-Tosyl-7a-(4-(trifluoromethyl)phenyl)-3-((trimethylsilyl)methylene)-2,3,3a,4-
1
tetrahydro-1H-indol-5(7aH)-one (2i). yellow oil; (32 mg; 62% yield); H NMR (400
MHz, CDCl ): δ 7.56-7.42 (m, 7H), 7.26 (d, J = 7.6 Hz, 2H), 6.24 (d, J = 10.0 Hz,
3
1
H), 5.46 (s, 1H), 4.29 (d, J = 14.0 Hz, 1H), 4.23 (d, J = 14.0 Hz, 1H), 3.21 (brs, 1H),
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2.60 (dd, J = 17.2, 2.8 Hz, 1H), 2.44 (s, 3H), 2.30 (dd, J = 16.8, 4.4 Hz, 1H), 0.09 (s,
1
3
9
H); C NMR (100 MHz, CDCl ): δ 195.7, 149.4, 145.9, 144.2, 137.3, 131.2, 130.5
3
(q, J = 32.2 Hz), 129.7, 127.3, 127.1, 125.5 (q, J = 3.2 Hz), 124.0 (q, J = 270.8 Hz),
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
9
122.5, 70.4, 56.1, 52.3, 35.6, 21.7, -0.7; F NMR (376 MHz, CDCl ): δ -62.6; IR
3
-1
(
neat, cm ): 2953, 1691, 1641, 1619, 1597, 1324, 1109, 838;HRMS calculated for
+
C H F N O SSi (M+NH ) : 537.1850; Found: 537.1842.
26
32
3
2
3
4
(Z)-7a-(Naphthalen-2-yl)-1-tosyl-3-((trimethylsilyl)methylene)-2,3,3a,4-tetrahydro-
o
1
1
H-indol-5(7aH)-one (2j). white solid; (40 mg; 80% yield); m.p.: 131-133 C; H
NMR (400 MHz, CDCl ): δ 7.84-7.82 (m, 1H), 7.76-7.71 (m, 3H), 7.57-7.41 (m, 6H),
3
7
.16 (d, J = 8.4 Hz, 2H), 6.27 (d, J = 10.4 Hz, 1H), 5.46 (s, 1H), 4.35 (dt, J = 14.4, 2.0
Hz, 1H), 4.28 (d, J = 14.0 Hz, 1H), 3.35 (brs, 1H) 2.60 (dd, J = 17.2, 4.0 Hz, 1H),
1
3
2
.40 (s, 3H), 2.34 (dd, J = 16.8, 4.8 Hz, 1H), 0.10 (s, 9H); C NMR (100 MHz,
CDCl ): δ 196.4, 150.1, 147.1, 143.8, 137.6, 137.0, 133.1, 132.9, 130.8, 129.5, 128.5,
3
128.3, 127.7, 127.3, 126.7, 126.6, 126.1, 124.2, 121.9, 71.1, 55.8, 52.4, 35.7, 21.7,
-1
-
0.6; IR (neat, cm ): 2954, 2920, 2851, 1690, 1645, 1596, 1330, 840, 808;HRMS
+
calculated for C H N O SSi (M+NH ) : 519.2132; Found: 519.2129.
2
9
35
2
3
4
(Z)-3-((tert-Butyldimethylsilyl)methylene)-7a-methyl-1-tosyl-2,3,3a,4-tetrahydro-1H-
o
1
indol-5(7aH)-one (2k). yellow solid; (31 mg; 72% yield); m.p.: 111-113 C; H NMR
(400 MHz, CDCl ): δ 7.75 (d, J = 8.4 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 6.95 (dd, J =
3
1
0.4, 1.6 Hz, 1H), 5.83 (d, J = 10.4 Hz, 1H), 5.47 (d, J = 2.4 Hz, 1H), 4.09 (d, J =
15.2 Hz, 1H), 4.05 (d, J = 12.4 Hz, 1H), 2.91 (brs, 1H), 2.71 (dd, J = 16.8, 4.4 Hz,
1
H), 2.57 (dd, J = 16.8, 5.2 Hz, 1H), 2.43 (s, 3H), 1.70 (s, 3H), 0.80 (s, 9H), 0.04 (s,
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3H), 0.02 (s, 3H); C NMR (100 MHz, CDCl ): δ 196.1, 151.1, 149.6, 143.8, 138.4,
3
1
29.9, 128.3, 127.1, 120.0, 65.0, 53.1, 52.5, 37.0, 23.7, 21.7, 20.4, 17.4, -4.9, -5.0; IR
-1
(
neat, cm ): 2951, 2927, 2854, 1687, 1639, 1598, 1334, 1157, 816;HRMS
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
+
calculated for C H N O SSi (M+NH ) : 449.2289; Found: 449.2280.
2
3
37
2
3
4
(
Z)-3-((Dimethyl(phenyl)silyl)methylene)-7a-methyl-1-tosyl-2,3,3a,4-tetrahydro-1H-
o
1
indol-5(7aH)-one (2l). white solid; (32 mg; 70% yield); m.p.: 105-106 C; H NMR
400 MHz, CDCl ): δ 7.59 (d, J = 8.4 Hz, 2H), 7.43-7.25 (m, 7H), 6.88 (d, J = 10.0,
(
3
1
.2 Hz, 1H), 5.84 (d, J = 10.4 Hz, 1H), 5.62 (d, J = 2.4 Hz, 1H), 3.82 (d, J = 16.4 Hz,
1H), 3.78 (d, J = 14.8 Hz, 1H), 2.91 (brs, 1H), 2.71 (dd, J = 17.2, 4.4 Hz, 1H), 2.69
(
dd, J = 16.8, 5.2 Hz, 1H), 2.43 (s, 3H), 1.69 (s, 3H), 0.33 (d, J = 2.8 Hz, 6H);
1
3
1
C{ H} NMR (100 MHz, CDCl ): δ 196.0, 152.2, 149.5, 143.7, 138.1, 137.8, 133.8,
3
1
29.8, 129.4, 128.4, 128.1, 127.1, 120.3, 65.0, 52.9, 52.2, 36.8, 23.8, 21.7, -1.8, -1.9;
-1
IR (neat, cm ): 2957, 1685, 1636, 1597, 1333, 1156, 814;HRMS calculated for
+
C H N O SSi (M+NH ) : 469.1976; Found: 469.1969.
25
33
2
3
4
(
Z)-7a-Methyl-1-tosyl-3-((triethylsilyl)methylene)-2,3,3a,4-tetrahydro-1H-indol-
o
1
5(7aH)-one (2m). white solid; (23 mg; 53% yield); m.p.: 107-109 C; H NMR (400
MHz, CDCl ): δ 7.76 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.0 Hz, 2H), 6.96 (dd, J = 10.0,
3
1
.2 Hz, 1H), 5.83 (d, J = 10.4 Hz, 1H), 5.43 (s,1H), 4.07 (s, 2H), 2.93 (s, 1H), 2.71
(dd, J = 16.8, 4.4 Hz, 1H), 2.57 (dd, J = 16.8, 5.2 Hz, 1H), 2.44 (s, 3H), 1.70 (s, 3H),
13
1
0
.86 (t, J = 8.0 Hz, 9H), 0.56 (q, J = 8.0 Hz, 6H); C{ H} NMR (100 MHz, CDCl ):
3
δ 196.1, 151.3, 149.6, 143.8, 138.5, 129.9, 128.3, 127.1, 119.4, 65.0, 52.9, 52.4, 36.9,
-1
2
3.8, 21.7, 7.5, 3.9; IR (neat, cm ):2950, 2910, 2871, 1690, 1639, 1595, 1335,
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1
1
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2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
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4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
+
1157, 1008;HRMS calculated for C H N O SSi (M+NH ) : 449.2289; Found:
2
3
37
2
3
4
4
49.2288.
(
Z)-3-Ethylidene-7a-methyl-1-tosyl-2,3,3a,4-tetrahydro-1H-indol-5(7aH)-one
(2n).
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
o
1
white solid; (23 mg; 69% yield); m.p.: 103-105 C; H NMR (400 MHz, CDCl ): δ
3
7
.76 (d, J = 8.4 Hz, 2H), 7.31 (d, J = 8.4 Hz, 2H), 6.96 (d, J = 10.4 Hz, 1H), 5.84 (d, J
= 10.4 Hz, 1H), 5.39-5.33 (m, 1H), 4.06 (d, J = 16.4 Hz, 1H), 4.01 (d, J = 16.4 Hz,
1
2
H), 2.88 (brs, 1H), 2.61 (dd, J = 16.8, 4.4 Hz, 1H), 2.53 (dd, J = 17.2, 5.2 Hz, 1H),
1
3
1
.43 (s, 3H), 1.67 (s, 3H), 1.56 (dd, J = 6.8, 1.2 Hz, 1H); C{ H} NMR (100 MHz,
CDCl ): δ 196.5, 149.7, 143.7, 138.6, 134.4, 129.9, 128.3, 127.1, 118.3, 65.5, 50.3,
3
-1
5
0.2, 37.2, 23.6, 21.7, 14.4; IR (neat, cm ): 2920, 2852, 1683, 1597, 1494, 1330,
+
1153, 815;HRMS calculated for C H N O S (M+NH ) : 349.1580; Found:
1
8
25
2
3
4
3
49.1573.
(
Z)-3-(2,2-Dimethylpropylidene)-7a-methyl-1-tosyl-2,3,3a,4-tetrahydro-1H-indol-
o
1
5(7aH)-one (2o). yellow solid; (19 mg; 51% yield); m.p.: 106-108 C; H NMR (400
MHz, CDCl ): δ 7.75 (d, J = 8.4 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 6.97 (dd, J = 10.4,
3
0.8 Hz, 1H), 5.86 (d, J = 10.4 Hz, 1H), 5.25 (s, 1H), 4.20 (d, J = 1.6 Hz, 2H), 2.84
13
1
(
brs, 1H), 2.59-2.43 (m, 2H), 2.43 (s, 3H), 1.65 (s, 3H), 1.02 (s, 9H); C{ H} NMR
(
100 MHz, CDCl ): δ 196.6, 149.5, 143.7, 138.4, 134.7, 130.2, 129.9, 128.5, 127.0,
3
-1
64.0, 52.1, 49.6, 38.0, 33.3, 30.2, 23.8, 21.7; IR (neat, cm ): 2960, 2867, 1685,
+
1
598, 1494, , 1330, 1155, 814;HRMS calculated for C H N O S (M+NH ) :
2
1
31
2
3
4
391.2050; Found: 391.2041.
Deuterium-labeling experiments. The procedures for deuterium-labeling
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experiments were similar to the reaction as shown in Table 2 by using CH CH OD
3
2
and CH CD OH as the solvents.
3
2
1
d-2a: H NMR (400 MHz, CDCl ): δ 7.76 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.4 Hz,
3
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
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0
2H), 6.97 (dt, J = 10.0, 1.6 Hz, 1H), 5.84 (dd, J = 10.0, 0.8 Hz, 1H), 5.47 (t, J = 2.0
Hz, 1H), 4.07 (s, 2H), 2.89 (brs, 1H), 2.65 (d, J = 4.0 Hz, 0.58H), 2.54 (d, J = 4.8 Hz,
0.54H), 2.44 (s, 3H), 1.70 (s, 3H), 0.06 (s, 9H).
1
d-2a’: H NMR (400 MHz, CDCl ): δ 7.76 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.4 Hz,
3
2
H), 6.97 (dd, J = 10.4, 0.8 Hz, 1H), 5.84 (d, J = 10.4 Hz, 1H), 5.47 (t, J = 2.4 Hz,
0.03H), 4.08 (s, 2H), 2.89 (brs, 1H), 2.68 (dd, J = 17.2, 4.4 Hz, 1H), 2.56 (dd, J = 16.8,
.2 Hz, 1H), 2.44 (s, 3H), 1.70 (s, 3H), 0.06 (s, 9H).
Transformation of product 2a to compounds 3a and 4a. Compound 3a and 4a was
5
1
0a
synthesized following published procedures with appropriate modifications.
(Z)-3-(Iodomethylene)-7a-methyl-1-tosyl-2,3,3a,4-tetrahydro-1H-indol-5(7aH)-one
o
1
(
3a). white solid; (33 mg; 74% yield from 0.1 mmol of 2a); m.p.: 145-148 C; H
NMR (400 MHz, CDCl ): δ 7.76 (d, J = 8.0 Hz, 2H), 7.32 (d, J = 8.0 Hz, 2H), 6.96 (d,
3
J = 10.0 Hz, 1H), 6.15 (q, J = 2.4 Hz, 1H), 5.90 (d, J = 10.0 Hz, 1H), 4.03-3.92 (m,
13
1
2
H), 2.93 (brs, 1H), 2.66-2.54 (m, 2H), 2.43 (s, 3H), 1.68 (s, 3H); C{ H} NMR (100
MHz, CDCl ): δ 195.1, 149.2, 146.8, 144.1, 138.1, 130.0, 128.7, 127.1, 72.6, 66.5,
3
-
1
5
1
4
7.0, 52.3, 36.8, 23.8, 21.7; IR (neat, cm ):  3571, 3119, 3056, 2921, 2852, 1597,
+
493, 1315, 1149, 1093, 839; HRMS calculated for C H IN O S (M+NH ) :
1
7
22
2
3
4
61.0390; Found: 461.0384.
(Z)-7a-Methyl-3-(3-phenylprop-2-yn-1-ylidene)-1-tosyl-2,3,3a,4-tetrahydro-1H-indol
-5(7aH)-one (4a). yellow solid; (33 mg; 79% yield from 0.1 mmol of 3a); m.p.: 61-63
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3
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4
4
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6
o
1
C; H NMR (400 MHz, CDCl ): δ 7.79 (d, J = 8.0 Hz, 2H), 7.42-7.40 (m, 2H),
3
7
.34-7.31 (m, 5H), 6.99 (dd, J = 10.4, 0.8 Hz, 1H), 5.91 (d, J = 10.4 Hz, 1H), 5.64 (q,
J = 2.4 Hz, 1H), 4.34 (t, J = 2.0 Hz, 2H), 3.07 (d, J = 1.6 Hz, 1H), 2.64 (d, J = 5.2 Hz,
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
3
1
2H), 2.44 (s, 3H), 1.72 (s, 3H); C{ H} NMR (100 MHz, CDCl ): δ 195.4, 149.4,
3
1
48.3, 144.0, 138.4, 131.6, 130.0, 128.7, 128.6, 128.5, 127.1, 122.9, 103.9, 96.4, 84.7,
-1
65.8, 52.1, 50.7, 36.9, 23.7, 21.7; IR (neat, cm ): 3052, 2923, 2251, 1685, 1596,
+
1
4
491, 1333, 1153; HRMS calculated for C H N O S (M+NH ) : 435.1737; Found:
2
5
27
2
3
4
35.1733.
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the ACS Publications
website at DOI:
1
13
Copies of H, C NMR spectra data for all compounds
1
9
Copies of F NMR spectra data for compounds 1g, 1i, 2g and 2i
X-ray crystallographic data for 2a (CIF)
AUTHOR INFORMATION
Corresponding Author
*
E-mail: xlhan@mail.sioc.ac.cn.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
We thank the National Natural Science Foundation of China (21232006, 21642002)
and Chinese Academy of Sciences for financial support.
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References
(1) For the reviews on cyclizations of enynes, see: (a) Aubert, C.; Buisine, O.;
Malacria, M. Chem. Rev. 2002, 102, 813. (b) Zhang, Z.; Zhu, G.; Tong, X.; Wang, F.;
Xie, X.; Wang, J.; Jiang, L. Curr. Org. Chem. 2006, 10, 1457. (c) Zhang, L.; Sun, J.;
Kozmin, S. A. Adv. Synth. Catal. 2006, 348, 2271. (d) Michelet, V.; Toullec, P. Y.;
Genêt, J.-P. Angew. Chem. Int. Ed. 2008, 47, 4268. (e) Carlotta, R.; Stefano, P.;
Davide, R.; Maurizio, F. Chem. Soc. Rev. 2016, 45, 4364. (f) Harris, R. J.;
Widenhoefer, R. A. Chem. Soc. Rev. 2016, 45, 4533. (g) Xuan, J.; Studer, A. Chem.
Soc. Rev. 2017, 46, 4329.
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
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4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
(2) For the reviews, see: (a) Kalstabakken, K. A.; Harned, A. M. Tetrahedron 2014,
7
0, 9571. (b) ꢀꢁꢂꢃꢄꢂꢅꢆ, ꢇ.ꢈ ꢀꢉnard, M.-A.; Canesi, S. Synthesis 2014, 46, 1573.
(3) (a) Tello-Aburto, R.; Harned, A. M. Org. Lett. 2009, 11, 3998. (b) Tello-Aburto,
R.; Kalstabakken, K. A.; Harned, A. M. Org. Biomol. Chem. 2013, 11, 5596. (c)
Takenaka, K.; Mohanta, S. C.; Sasai, H. Angew. Chem. Int. Ed. 2014, 53, 4675.
(4) (a) Keilitz, J.; Newman, S. G.; Lautens, M. Org. Lett. 2013, 15, 1148. (b) He,
Z.-T.; Tian, B.; Fukui, Y.; Tong, X.; Tian, P.; Lin, G.-Q. Angew. Chem. Int. Ed. 2013,
52, 5314. (c) Murthy, A. S.; Donikela, S.; Reddy, C. S.; Chegondi, R. J. Org. Chem.
2
015, 80, 5566. (d) Clarke. C.; Incerti-Pradillos, C. A.; Lam, H. W. J. Am. Chem.
Soc. 2016, 138, 8068.
5) Liu, P.; Fukui, Y.; Tian, P.; He, Z.-T.; Sun, C.-Y.; Wu, N.-Y.; Lin, G.-Q. J. Am.
(
Chem. Soc. 2013, 135, 11700.
(6) Fukui, Y.; Liu, P.; Liu, Q.; He, Z.-T.; Wu, N.-Y.; Tian, P.; Lin, G.-Q. J. Am. Chem.
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Soc. 2014, 136, 15607.
(7) He, C.; Zhu, C.; Dai, Z.; Tseng, C.-C.; Ding, H. Angew. Chem. Int. Ed. 2013, 52,
13256.
0
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(
8) Trost, B. M.; Rise, F. J. Am. Chem. Soc. 1987, 109, 3161.
9) For the review, see: (a) Lu, X. Top. Catal. 2005, 35, 73. For selected work
published recently, see: (b) Xia, G.; Han, X.; Lu, X. Adv. Synth. Catal. 2012, 354,
701. (c) Xia, G.; Han, X.; Lu, X. Org. Lett. 2014, 16, 6184. (d) Xia, G.; Han, X.; Lu,
(
2
X. Org. Lett. 2014, 16, 2058. (e) Zhang, J.; Han, X.; Lu, X. Synlett 2015, 26, 1744. (f)
Zhang, J.; Han, X.; Lu, X. J. Org. Chem. 2016, 81, 3423. (g) Chen, J.; Han, X.; Lu, X.
J. Org. Chem. 2017, 82, 1977.
(10) (a) Shen, K.; Han, X.; Lu, X. Org. Lett. 2013, 15, 1732. (b) Shen, K.; Han, X.;
Xia, G.; Lu, X. Org. Chem. Front. 2015, 2, 145. (c) Zhang, X.; Han, X.; Hu, Z.; Lu, X.
Synthesis 2017, 49, 4687.
(11) (a) Jang, H.-Y.; Krische, M. J. J. Am. Chem. Soc. 2004, 126, 7875. (b) Jang,
H.-Y.; Hughes, F. W.; Gong, H. Zhang, J.; Brodbelt, J. S.; Kriche, M. J. J. Am. Chem.
Soc. 2005, 127, 6174. (c) Jung, I. G.; Seo, J.; Lee, S. I.; Chung, Y. K.
Organometallics 2006, 25, 4240. (d) Jang, M.-S.; Wang, X.; Jang, W.-Y.; Jang, H.-Y.
Organometallics 2009, 28, 4841. (e) Sylvester, K. T.; Chirik, P. J. J. Am. Chem. Soc.
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009, 131, 8772. (f) Hoyt, J.; Sylvester, K. T.; Semproni, S. P.; Chirik, P. J. J. Am.
Chem. Soc. 2013, 135, 4862.
12) (a) Trost, B. M.; Rise, F. J. Am. Chem. Soc. 1987, 109, 3161. (b) Yamada, H.;
(
Aoyagi, S.; Kibayashi, C. Tetrahedron Lett. 1996, 37, 8787.
(13) (a) Montgomery, J.; Savchenko, A. V.; J. Am. Chem. Soc. 1996, 118, 2099. (b)
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279. (c) Lin, A.; Zhang, Z.-W.; Yang, J. Org. Lett. 2014, 16, 386.
14) Chang, H. -T.; Jayanth, T. T.; Wang, C.-C.; Cheng, C.-H.; J J. Am. Chem. Soc.
2007, 129, 12032.
15) In the literature, there is only one example on enyne reductive cyclization using
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alcohol as the hydrogen source (catalyzed by rhodium): Park, J. H.; Kim, S. M.;
Chung, Y. K. Chem. Eur. J. 2011, 17, 10852.
(16) The relative stereochemistry of 2a was assigned as cis-version on the basis of
X-ray diffraction (see the Supporting Information).
(17) Jia, P.; Zhang, Q.; Jin, H.; Huang, Y. Org. Lett. 2017, 19, 412.
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