Gold(I)-Catalyzed Cycloisomerization of ortho-(Propargyloxy)arenemethylenecyclopropanes Controlled by Adjacent Substituents at Aromatic Rings

Article abstract of DOI:10.1002/chem.201700600

Gold(I)-catalyzed cycloisomerization of ortho-(propargyloxy)arenemethylenecyclopropanes afforded two different types of products, that is, products of methylenecyclopropane migration and cycloisomerization products of the methylenecyclopropane moiety, con

Full text of DOI:10.1002/chem.201700600

A Journal of
Accepted Article
Title: Gold(I)-catalyzed cycloisomerization of ortho-
(propargyloxy)arenemethylenecyclopropanes controlled by
adjacent substituent at aromatic rings
Authors: Min Shi, Wei Fang, Yin Wei, and Xiang-Ying Tang
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Chem. Eur. J. 10.1002/chem.201700600
Link to VoR: http://dx.doi.org/10.1002/chem.201700600
Supported by

10.1002/chem.201700600
Chemistry - A European Journal
Gold Catalysis
Gold(I)-catalyzed cycloisomerization of ortho-
(propargyloxy)arenemethylenecyclopropanes controlled by adjacent substituent at
aromatic rings
Wei Fang, Yin Wei, Xiang-Ying Tang, and Min Shi*
Abstract: Gold(I)-catalyzed cycloisomerization of ortho-
(propargyloxy)arenemethylenecyclopropanes afforded two different
types of products, including methylenecyclopropane migration
moiety would be able to initiate a new cycloisomerization process to
give novel cyclization product upon gold catalysis. Consequently,
we
designed
and
prepared
ortho-
products
and
cycloisomerization
products
from
(propargyloxy)arenemethylenecyclopropanes as substrates to
examine the reaction outcome. Herein, we wish to report that two
different types of cycloisomerization products can be afforded in the
methylenecyclopropane moiety, controlled jointly by electronic
effect and steric effect of the adjacent substituents. Furthermore, the
corresponding cycloisomerization products could be also produced
in an enantiomerically enriched manner.
t
presence of gold catalyst. When the adjacent substituents were Bu
or tAm group, methylenecyclopropane migration product 2H-
chromenes 2 were formed efficiently. When aromatic core was
substituted by Me, MeO or halogen atom, the corresponding 2,3-
dihydrobenzofuran fused allene derivatives 4 derived from ring
enlargement of methylenecyclopropane moiety along with migration
of propargyl group could be produced (Scheme 1). To the best of
our knowledge, this is the first report with regard to the migration of
entire methylenecyclopropane unit upon gold catalysis. Furthermore,
the corresponding allenic products could be also produced in an
enantiomerically enriched manner in the presence of chiral gold
catalyst.
Gold catalysis as a convenient and powerful tool for synthetic
organic chemistry[1] now has witnessed a rushing development in
the past decades due to its potential for the rapid and available
construction of the constitutional units,[2] which was widely
employed in organic transformations, medicinal chemistry and total
synthesis.[2f,
Metal-catalyzed cycloisomerization along with
3]
carbon skeleton migration is a very important strategy for the
construction of complex molecules in organic synthesis. During the
past decades, gold(I)-catalyzed such cycloisomerizations[4] and
carbon skeleton migration reactions have made significant progress
including H-migration,[5] halogen migration,[6] N-migration,[7] O-
migration,[8] and C-migration.[3r, 9]
Recently, Waldmann’s group reported that ortho-(propargyloxy)
styrenes I could be converted to 2H-1-benzoxocines II based on an
8-endo-dig cyclization under gold catalysis (Scheme 1).[10]
Methylenecyclopropanes as useful building blocks due to their
highly strained ring energy[2l, 11] have been extensively investigated
under transition metal catalysis or Lewis acid catalysis.[12] Therefore,
we envisaged that methylenecyclopropane moiety replacing alkene
[]
W. Fang, Prof. Dr. M. Shi
Key Laboratory for Advanced Materials and Institute of Fine
Chemicals, School of Chemistry & Molecular Engineering,
East China University of Science and Technology, Meilong
Road No. 130, Shanghai, 200237 (China)
Y. Wei, X. Y. Tang, Prof. Dr. M. Shi
Scheme 1. Previous work and this work.
We initially optimized the reaction conditions for the formation
of 2d using 1d as a model substrate and the screening results are
shown in Table 1. Using JohnPhosAuCl/AgSbF6, Me4-
State Key Laboratory of Organometallic Chemistry
Shanghai Institute of Organic Chemistry
Chinese Academy of Sciences
345 Lingling Road, Shanghai, 200032 (China)
E-mail: mshi@mail.sioc.ac.cn.
tBuXPhosAuCl/AgSbF6,
tBuXPhosAuCl/AgSbF6,
and
Ph3PAuCl/AgSbF6 as catalyst and carrying out the reaction in 1,2-
dichloroethane (DCE) at room temperature, the reactions did not
take place along with the recovery of 1d (Table 1, entries 1-4).
However, in the presence of (p-FC6H4)3PAuCl/AgSbF6 (2.5 mol%),
2d was given in 70% yield within 6 hours (Table 1, entry 5). Using
(p-CF3C6H4)3PAuCl/AgSbF6 (2.5 mol%) as the catalyst afforded 2d
in a yield up to 75% in DCE at room temperature within 6 hours
(Table 1, entry 6). Replacing AgSbF6, the counter anion of gold
complex, with AgNTf2 and AgOTf, we found that the yields of 2d
decreased significantly (Table 1, entries 7 and 8). Carrying out the
reaction in DCE at 90 oC did not give 2d in the presence of
JohnPhosAuCl/AgSbF6 (2.5 mol%) (Table 1, entry 9), and complex
product mixture was formed in the presence of Me4-
tBuXPhosAuCl/AgSbF6 (2.5 mol%) (Table 1, entry 10). The yield
Prof. Dr. M. Shi
State Key Laboratory and Institute of Elemento-organic
Chemistry, Nankai University, Tianjin 300071, P. R. China.
[] We are grateful for the financial support from the National
Basic Research Program of China (973)-2015CB856603, the
Strategic Priority Research Program of the Chinese Academy
of Sciences, Grant No. XDB20000000, the National Natural
Science Foundation of China (20472096, 21372241,
21572052, 20672127, 21421091, 21372250, 21121062,
21302203, and 20732008), and the Fundamental Research
Funds for the Central Universities 222201717003. We are
grateful for the facility support from Shanghai Supercomputer
Center.
Supporting information for this article is available on the
WWW under http://www.chem.org or from the author.
1
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
of 2d was 62% in DCE at 90 oC within 6 hours using (p-
CF3C6H4)3PAuCl/AgSbF6 (2.5 mol%) as the catalyst (Table 1, entry
11). Finally, the examination of solvent effects revealed that no
reaction occurred in THF and 65% and 72% yields of 1d were
obtained in dichloromethane (DCM) and toluene, respectively
(Table 1, entries 12-14).
Table 1. Optimization of the reaction conditions for the synthesis of
2d.
tBu
tBu
catalyst (2.5 mol%)
solvent
O
O
tBu
tBu
1d
2d
entrya
catalyst
solvent
DCE
time (h) yield (%)
temp (oC)
NR
1
2
3
4
5
6
7
8
9
JohnPhosAuCl/AgSbF6
Me4-t-BuXPhosAuCl/AgSbF6 DCE
t-BuXPhosAuCl/AgSbF6
Ph3PAuCl/AgSbF6
(p-FC6H4)3PAuCl/AgSbF6
(p-CF3C6H4)3PAuCl/AgSbF6
(p-CF3C6H4)3PAuCl/AgNTf2
(p-CF3C6H4)3PAuCl/AgOTf
JohnPhosAuCl/AgSbF6
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
6
4
4
In the proceeding on the examination of substrate scope, we
NR
NR
found that the corresponding 2,3-dihydrobenzofurans
4 were
DCE
DCE
DCE
DCE
DCE
DCE
DCE
obtained when the substituent R1 is not a sterically bulky one. In this
reaction, methylenecyclopropane underwent ring-expanding and
nucelophilic attack by oxygen atom along with the rearrangement of
propargyl group to give the 2,3-dihydrobenzofurans 4. Utilizing the
above optimal reaction condition, substrate 3e was converted to 2,3-
dihydrobenzofuran 4e in a satisfied 92% yield (Scheme 2). Thus, we
did not further screen the reaction conditions and utilized it as the
optimal reaction conditions for this transformation.
NR
70
4
6
6
75
r.t.
r.t.
90
90
90
6
6
6
1
6
37b
24b
NR
complex
62b
10 Me4-t-BuXPhosAuCl/AgSbF6 DCE
11
12
13
14
DCE
DCM
THF
(p-CF3C6H4)3PAuCl/AgSbF6
(p-CF3C6H4)3PAuCl/AgSbF6
(p-CF3C6H4)3PAuCl/AgSbF6
(p-CF3C6H4)3PAuCl/AgSbF6
r.t.
r.t.
r.t.
6
6
6
65b
NR
72b
toluene
a Reaction conditions: 1d (0.2 mmol), catalyst (2.5 mol %), solvent (2.0 mL),
isolated yields. b Yields were determined by 1H NMR spectroscopy. NR is no
reaction.
With these reaction conditions established, we next investigated
the scope of the reaction with respect to various substituted ortho-
(propargyloxy)arenemethylenecyclopropanes 1. As shown in Table
2, when the substituent R1 was tBu and substituent R2 was H, Me, Et,
Scheme 2. Optimal reaction conditions for the synthesis of 4e.
t
We next examined the generality of this reaction under the
optimal conditions shown in Scheme 2, and the results are shown in
Table 3. When R3 was a H atom; R1 was a Me, halogen atom, or
MeO; and R2 was a H atom or a halogen atom, these reactions
proceeded smoothly under the optimal condition, giving the desired
products in good to excellent yields; although in the cases of 3a and
and Bu group, the desired 2H-chromenes 2a, 2b, 2c, and 2d were
afforded in 94%, 80%, 78%, and 75% yields, respectively; and the
structure of 2d was assigned by X-ray diffraction (see Supporting
Information for the details). With the increase of steric hindrance of
the substituent R2, the yields of 2 decreased (Table 2, entries 1-4),
presumably due to that the steric hindrance of R2 impaired the
migration of methylenecyclopropane moiety, thereby resulting in the
o
3c, the reaction temperature was raised to 60 C (Table 3, entries 1-
8). When R3 was an alkyl or aryl group, the reactions also proceeded
efficiently to afford the desired products in moderate to good yields.
As for substrates 3i-3l, in which both of R1 and R2 were Br atom and
t
formation of 2 in lower yields. When the substituent R1 was a Bu
group and substituent R2 was a MeO, the reaction gave a product
mixture (Table 2, entry 5). Consistent with the above results, when
the substituent R1 was tAm and R2 was H or tAm, the target products
2f and 2g were afforded in 84% and 75% yields, respectively (Table
2, entries 6 and 7). Meanwhile, we also synthesized substrate 1h
bearing a nitrogen atom at the aromatic ring, but found that none of
the corresponding product could be yielded under the optimal
reaction conditions (Table 2, entry 8).
R3 was a Me, Et, nAm or cyclopropyl group, the desired products 4i-
4l were obtained in 72%, 69%, 58%, 62%, and 56% yields,
respectively (Table 3, entries 9-12). The decrease of yields may be
due to that the terminal alkynyl substituent sterically does not
facilitate the intramolecular cyclization. Introducing heterocycle at
terminal alkyne, the corresponding substrate 3m was also
transformed to the desired product 4m in 56% yield (Table 3, entry
13). When R3 was a phenyl group; R1 was a halogen atom or a
methoxy group; R2 was a H atom or a halogen atom, the desired
products 4n-4r were also produced in good yields ranging from 65%
to 82% yields, respectively (Table 3, entries 14-18). Interestingly, in
the case of substrate 3s, in which R3 was a phenyl group; both of R1
Table
2.
Substrate
scope
of
ortho-
(propargyloxy)arenemethylenecyclopropanes 1 to 2H-chromenes 2.
and R2 were tBu group, the corresponding product 4s was formed in
63% yield under the optimal conditions rather than the
methylenecyclopropane migration, suggesting that the terminal
alkynyl substituent would block out the intramolecular
hydroarylation (Table 3, entry 19). Moreover, introducing CO2Et
and TIPS at terminal alkyne (substrates 3t and 3u) did not produce
the desired products under the standard conditions (Table 3, entries
20 and 21).
Table
3.
Substrate
scope
of
ortho-
(propargyloxy)arenemethylenecyclopropanes
3
to
2,3-
dihydrobenzofurans 4.
2
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
rearrangement[14] took place to afford a seven-membered ring
product 6a in 60% yield rather than the expected migration product
(see Scheme S1 in the Supporting Information). The structure of 6a
has been assigned by X-ray diffraction (see Supporting Information
for the details). In the case of substrate 5b, seven-membered ring
product 6b and allenic product 6b’ were both formed in 82% total
yield at the same time. These reactions are able to access seven-
membered ether fused with a benzene. This type of product can be
accessed by other gold reactions.[15] However, as for substrates 7a
and 7b, no reactions occurred along with the recovery of substrates
7a and 7b.
On the basis of the above outcomes, we attempted to develop an
asymmetric variant for the synthesis of 2,3-dihydrobenzofurans 4.
The optimization of these chiral gold catalysts revealed that DTBM-
SegPhos ligand coordinated gold complex with NaBArF[13] gave the
highest ee value in toluene (see Table S1 in the Supporting
Information for the details). As shown in Scheme 3, the
corresponding products 4 could be obtained in moderate to good
yields along with 62-95% ee values. The substituent R3 has a vital
effect on ee value in the asymmetric production of 2,3-
dihydrobenzofurans 4. When the substituent R3 was alkyl group, the
corresponding product was formed in a lower enantioselectivity. If
the substituent R3 was a phenyl group, the ee value of 4q could
reach to 95% perhaps due to that phenyl ring could improve
enantioselectivity during the migration of propargyl group. The
absolute configuration of 4n has been assigned by X-ray diffraction
(see Supporting Information for the details).
Scheme 4. Reactions of substrates 5a and 5b and 7a and 7b upon
gold(I) catalysis .
On the basis of our previous investigation,[16] we carried out a
further transformation of 2d as shown in Scheme 5. Compound 2d
could be converted into the corresponding cyclobutene 8 in a 88%
o
yield at 90 C in DCE via a ring enlargement in the presence of
IPrAuCl/AgSbF6 (2.5 mol%) within 4 hours. Next, we also explored
the regioselective epoxidation of 8 with meta-chloroperbenzoic acid
(m-CPBA) in DCM at 0 oC. In consequence, the corresponding
products cis-9a and trans-9b, derived from the ring-opening of the
in situ generated epoxide at six-membered olefin and further
esterification with meta-chlorobenzoic acid, were yielded in 36%
and 48% yields, respectively (Scheme 5). Upon treatment of 8 with
para-nitrobenzenesulfonyl chloride (NsCl) and triethylamine (TEA),
compound cis-9a could be transformed into compound cis-10 in
58% yield in DCM at room temperature within 6 hours along with
36% recovery of cis-9a. The relative configuration of cis-10 has
been unambiguously assigned by X-ray diffraction (see Supporting
Information for the details).
Scheme 3. Asymmetric version for the production of 4.
In addition, we also prepared substrates 5a and 5b bearing an
isoproylidene moiety as well as substrates 7a and 7b bearing a
cyclobutylidene moiety and examined their reaction outcomes under
the standard conditions. The results are shown in Scheme 4. As for
substrate 5a, a ring-closure process along with 1,3-cationic skeletal
3
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
ortho-substituents was carried out on the basis of the B3LYP/6-
tBu
tBu
31G(d, p) level, revealing that the electron densities on C2 atom
IPrAu(MeCN)Cl/AgSbF6 (2.5 mol%)
DCE, 90 oC, 4 h
t
follow the order of Bu > Me > Br > Cl > MeO > F (Table 4). This
O
O
tBu
tBu
result suggests that the ortho-substituents can influence the
formation of five-membered ring intermediate (Int-B in Scheme 7)
through changing the electron densities on C2 atom. When ortho-
8, 88%
2d
m-CPBA (2.0 eq)
DCM, 0 oC, 12 h
t
Cl
substituent is a Bu group, the cyclization can efficiently take place
O
O
due to higher electron density on C2 atom, thereby affording the
O
O
tBu
O
corresponding
exclusively.
methylenecyclopropane
migration
product
NsCl (1.5 eq)
SO2
tBu
OH
Cl
TEA (1.8 eq)
DCM, rt, 6 h
O
O
tBu
tBu
O2N
10, 58%
Table 4. Ortho-substituent effects.
9a, 36%
+
O
6
Y
5
1
O
tBu
OH
Cl
4
2
O
3
X
O
tBu
9b, 48%
NPA charge of C2 atoma
X
F
Y
H
Br
H
H
H
H
0.258
0.278
0.297
0.298
0.307
0.322
MeO
Cl
Scheme 5. Further transformation of 2d.
Br
Me
tBu
On the basis of the above results and previously reported
literature, the plausible mechanisms for these reactions are described
in Scheme 6. In Cycle I, the gold complex initially coordinated with
the triple bond of substrate 1a to give intermediate A, which
afforded the vinyl-gold[17] intermediate B containing a five-
membered ring through cyclization. Next, the ring enlargement of
a Calculated at B3LYP/6-31G(d, p) level.
Furthermore, we performed DFT calculations on the reaction
pathway about the unknown migration of methylenecyclopropane
moiety in Cycle I using substrates 1a and 3d and the reaction energy
profile was described in Scheme 7 (for computational details, see
Supporting Information). Initially, coordination of gold(I) catalyst to
the alkyne moiety of substrates 1a and 3d give gold complex Int-A
and Int-A’, respectively. Undergoing a ring-closure process, an
intermediate Int-B containing five-membered ring is formed via
transition state TS1 with an energy barrier of 9.4 kcal/mol along the
Path 1. Similarly, an intermediate Int-B’ is formed via transition
state TS1’ with an energy barrier of 11.8 kcal/mol along the Path 2,
correspondingly. Transition state TS1’ is higher than transition state
TS1 in energy by 2.4 kcal/mol, indicating that the substrate 1a
intermediate
B took place to afford intermediate C. Then,
intermediate C underwent three-membered ring transition state TS3
(Shown in Scheme 7) to form intermediate D via intramolecular
cyclopropanation[18] and methylenecyclopropane migration. Finally,
intermediate D underwent dehydro-aromatization and reprotonation
to afford 2a along with the regeneration of gold(I) catalyst. In Cycle
II, the gold complex initially activated the double bond of
methylenecyclopropane to produce intermediate E, which
rearranged to the corresponding cyclobutenyl cationic intermediate
F through ring enlargement.[12e, 19] Intermediate G, likely bearing
some gold carbenoid character,[20] was a resonance structure of
intermediate F. Then O atom attacked the cyclobutenyl cation to
give the corresponding propargylic ether oxonium ylide[21]
intermediate H, which underwent the corresponding [2,3]-
sigmatropic rearrangement[22] by C-O bond cleavage (O1'-C1) and
C-C bond formation (C2'-C3) and simultaneously dissociation of
gold catalyst to give the final product 4d.
t
having Bu substituent is more kinetically favored to undergo the
ring-closure step, presumably due to the more positive charge on C2
atom as shown in Table 4. Subsequently, Int-B undergoes ring
enlargement via transition state TS2 with an energy barrier of 0.1
kcal/mol along the Path 1, producing another intermediate Int-C.
Int-C’ is formed via transition state TS2’ with an energy barrier of
7.0 kcal/mol along the Path 2. The energy of transition state TS2’ is
still higher than that of transition state TS2 by 7.9 kcal/mol. Then,
intramolecular cyclopropanation takes place to give intermediate
Int-D via transition state TS3 with an energy barrier of 11.3
kcal/mol along the Path 1. Intermediate Int-D’ is formed via
transition state TS3’ with an energy barrier of 7.8 kcal/mol along the
Path 2. Transition state TS3’ is higher than transition state TS3 in
energy by 2.6 kcal/mol. These calculation results also show that all
intermediates along the Path 1 are more stable than those
corresponding intermediates along path 2, thus the Path 1 is also
thermodynamically favorable. Therefore, we conclude that the
reaction of substrate 1a along the Path 1 takes place more easily,
affording the corresponding product 2a. However, utilizing 3d as
substrate, the reaction is more difficult to occur along the Path 2;
presumably, it proceeded via the reaction process shown in Cycle II
Scheme 6. Proposed reaction mechanism.
We believe that the electronic effects of ortho-substituents in
substrates influence the electron densities of carbon atom (C2
position) at the aromatic ring substituted by the
methylenecyclopropanes, which is the root for the different reaction
pathways of substrates 1 and 3. The calculation of Natural
Population Analysis (NPA) charge on the C2 atom influenced by
more
easily
involving
the
ring
enlargement
of
methylenecyclopropane and [2,3]-sigmatropic rearrangement which
are already well-known and have been reported by Fürstner,[12e]
Echavarren,[19] Tang[22d] et al. Herein, we have no further study
about the reaction pathway in Cycle II.
4
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
Appropriate amount of silica gel was added to the reaction mixture
and the solvent was removed under vacuum pump at low
temperature. Then, the crude product was purified by silica gel
chromatography (PE) to get the desired product 4a (26 mg, 65%) as
GDCE,298 (kcal/mol)
AuL
AuL
O
Br
AuL
O
AuL
AuL
O
TS2'
15.1
Br
TS3'
13.1
O
Br
1
Br
O
TS1'
11.8
a colorless oil. H NMR (CDCl3, 400 MHz, TMS)  1.89-1.97 (m,
H
Br
Int-B'
8.1
AuL
TS3
10.5
O
1H, CH2), 2.23 (s, 3H, CH3), 2.29-2.39 (m, 1H, CH2), 2.51-2.55 (m,
2H, CH2), 3.79 (d, J = 7.6 Hz, 1H, CH), 5.00 (dd, J1 = 6.4 Hz, J2 =
1.6 Hz, 2H, =CH2), 5.54 (t, J = 6.4 Hz, 1H, =CH), 6.80 (dd, J1 = J2
= 7.6 Hz, 1H, Ar), 6.98 (d, J = 7.6 Hz, 1H, Ar), 7.01 (d, J = 7.6 Hz,
1H, Ar). 13C NMR (CDCl3, 100 MHz, TMS)  15.5, 23.8, 32.8, 47.9,
78.3, 87.6, 92.8, 120.4, 120.6, 122.3, 129.5, 131.3, 158.7, 207.8. IR
(neat)  3055, 2987, 2942, 2857, 1955, 1712, 1595, 1461, 1379,
1288, 1132, 1097, 922, 848 cm-1. MS (%) m/e 198 (M+, 15.37), 183
(8.72), 170 (100.00), 155 (8.45), 141 (30.69), 128 (8.23), 115
(30.87), 91 (12.41), 77 (12.79). HRMS (EI) calcd. for C14H14O:
198.1045, found: 198.1046.
Int-C'
Au+
L
TS1
9.4
5.3
Br
O
TS2
7.2
Int-B
7.1
Br
Int-A'
0.0
Int-D'
-3.5
AuL
Int-A
0.0
Int-C
-0.8
Path 2
Path 1
AuL
O
O
t
AuL
AuL
t
Bu
Bu
Int-D
-7.9
O
O
t
t
Bu
Bu
O
AuL
Au+
L
t
Bu
H
O
AuL
t
Bu
O
t
Bu
L = P(p-CF3C6H4
)
3
thermodynamically
favorable
Scheme 7. DFT studies on reaction pathway in cycle I.
In summary, we have developed a new strategy for the
cycloisomerization along with carbon skeleton migration of ortho-
(propargyloxy)arenemethylenecyclopropanes to afford two different
types of products in the presence of (p-CF3C6H4)3PAuCl/AgSbF6
catalyst. The product distributions were jointly controlled by
electronic effect and steric effect of the adjacent substituents at the
phenyl ring. When substituent was a sterically bulky one, this
transformation yielded methylenecyclopropane migration products 2
in good yields. When substituent was Me, MeO or halogen atom,
ring enlargement of methylenecyclopropane along with
rearrangement of propargyl group takes place to give products 4.
The corresponding products could be also produced in an
enantiomerically enriched manner through an asymmetric version.
Further investigations on the mechanistic details and exploration of
new methodology based on gold catalyzed transformations of
methylenecyclopropanes as well as their asymmetric variants are
currently underway in our laboratory.
Computational methods. All DFT calculations were performed
with Gaussian 09 program.[23] The geometries of all minima and
transition states have been optimized using PBE1PBE functional.[24]
The SDD basis set and pseudopotential were used for the gold atom,
and the 6-31G(d) basis set was used for other atoms. The subsequent
frequency calculations on the stationary points were carried out at
the same level of theory to ascertain the nature of the stationary
points as minima or first-order saddle points on the respective
potential energy surfaces. All transition states were characterized by
one and only one imaginary frequency pertaining to the desired
reaction coordinate. The intrinsic reaction coordinate (IRC)
calculations were carried out at the same level of theory to further
authenticate the transition states. The conformational space of
flexible systems has first been searched manually. Thermochemical
corrections to 298.15 K have been calculated for all minima from
unscaled vibrational frequencies obtained at this same level. The
solvent effect was estimated by the IEFPCM method[25] with radii
and nonelectrostatic terms for SMD salvation model[26] in
dichloroethane (ε = 10.37). Solution-phase single point energy
calculations (SDD basis set and pseudopotential used for the gold
atom, and the 6-31+G(d,p) basis set used for other atoms) were
performed based on the gas phase optimized structures.
Experimental Section
General procedure for the synthesis of compound 2a. To a flame-
dried flask were added the methylenecyclopropane (0.20 mmol, 1.0
equiv) and the (p-CF3C6H4)3PAuCl/AgSbF6 (0.005 mmol, 0.025
equiv), and the flask was evacuated and backfilled with Ar for 3
times. DCE (2.0 mL) was added to this flask via a syringe under Ar.
The reaction mixture was stirred for 6 hours at room temperature.
Appropriate amount of silica gel was added to the reaction mixture
and the solvent was removed under vacuum pump at low
temperature. Then, the crude product was purified by a silica gel
chromatography (PE) to get the desired product 2a (45 mg, 94%) as
Received: ((will be filled in by the editorial staff))
Published online on ((will be filled in by the editorial staff))
1
a colorless oil. H NMR (CDCl3, 400 MHz, TMS) 1.16-1.19 (m,
Keywords: gold-catalyzed, metheneylcyclopropane, migration, [2,3]-
2H, CH2), 1.35-1.40 (m, 11H, CH2, 3CH3), 4.65 (dd, J1 = 4.0 Hz, J2
= 1.6 Hz, 2H, CH2), 5.75 (dt, J1 = 10.0 Hz, J2 = 4.0 Hz, 1H, =CH),
6.84 (d, J = 10.0 Hz, 1H, =CH), 6.95 (s, 1H, =CH), 7.13 (d, J = 8.0
Hz, 1H, Ar), 7.25 (d, J = 8.0 Hz, 1H, Ar). 13C NMR (CDCl3, 100
MHz, TMS)  1.2, 4.2, 29.7, 34.3, 63.4, 114.2, 118.9, 120.8, 121.6,
122.4, 126.0, 126.1, 132.5, 136.0, 152.8. IR (neat)  3080, 2956,
2869, 1780, 1637, 1588, 1485, 1392, 1272, 1191, 1093, 967, 828
cm-1. MS (%) m/e 240 (M+, 1.55), 225 (16.49), 201 (100.00), 183
(34.02), 155 (16.75), 128 (30.27), 115 (33.49), 91 (24.92), 77
(17.52). HRMS (EI) calcd. for C17H20O: 240.1514, found: 240.1512.
sigmatropic rearrangement, cycloisomerization.
[1] a) B. W. Gung, L. N. Bailey, D. T. Craft, C. L. Barnes, K. Kirschbaum,
Organometallics 2010, 29, 3450; b) M. Bandini, A. Bottoni, M.
Chiarucci, G. Cera, G. P. Miscione, J. Am. Chem. Soc. 2012, 134,
20690; c) G. Cera, M. Chiarucci, M. Bandini, Pure Appl. Chem. 2012,
84, 1673; d) N. T. Patil, Chem. - Asian J. 2012, 7, 2186; e) V. Michelet,
Top Curr Chem 2015, 357, 95; f) A. La-Venia, N. S. Medran, V.
Krchnak, S. A. Testero, ACS Comb. Sci. 2016, 18, 482.
[2] For recent reviews on homogeneous gold catalysis, see: a) D. J. Gorin, F.
D. Toste, Nature 2007, 446, 395; b) A. Fürstner, P. W. Davies, Angew.
Chem. Int. Ed. 2007, 46, 3410; Angew. Chem. 2007, 119, 3478; c) E.
Jiménez-Núñez, A. M. Echavarren, Chem. Rev. 2008, 108, 3326; d) M.
M. Díaz-Requejo, P. J. Pérez, Chem. Rev. 2008, 108, 3379; e) A.
Fürstner, Chem. Soc. Rev. 2009, 38, 3208; f) M. Rudolph, A. S. K.
Hashmi, Chem. Soc. Rev. 2012, 41, 2448; g) C. Obradors, A. M.
Echavarren, Chem. Commun. 2014, 50, 16; h) A. S. K. Hashmi, Acc.
General procedure for the synthesis of compound 4a. To a flame-
dried flask were added the methylenecyclopropane (0.20 mmol, 1.0
equiv) and the (p-CF3C6H4)3PAuCl/AgSbF6 (0.005 mmol, 0.025
equiv), and the flask was evacuated and backfilled with Ar for 3
times. DCE (2.0 mL) was added to this flask via a syringe under Ar.
The reaction mixture was stirred for 6 hours at room temperature.
5
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
Chem. Res. 2014, 47, 864; i) L. Zhang, Acc. Chem. Res. 2014, 47, 877;
j) Y.-M. Wang, A. D. Lackner, F. D. Toste, Acc. Chem. Res. 2014, 47,
889; k) C. Obradors, A. M. Echavarren, Acc. Chem. Res. 2014, 47, 902;
l) D.-H. Zhang, X.-Y. Tang, M. Shi, Acc. Chem. Res. 2014, 47, 913; m)
A. Fürstner, Acc. Chem. Res. 2014, 47, 925; n) B. Alcaide, P. Almendros,
Acc. Chem. Res. 2014, 47, 939; o) L. Fensterbank, M. Malacria, Acc.
Chem. Res. 2014, 47, 953; p) H.-S. Yeom, S. Shin, Acc. Chem. Res.
2014, 47, 966; q) Y. Wang, M. E. Muratore, A. M. Echavarren, Chem. -
Eur. J. 2015, 21, 7332; u) B. J. Ayers, P. W. H. Chan, Synlett. 2015, 26,
1305; v) D. P. Day, P. W. H. Chan, Adv. Synth. Catal. 2016, 358, 1368.
[3] a) C. Ecob, Tecnol. Chim. 2000, 20, 84; b) A. Fürstner, P. Hannen, Chem.
- Eur. J. 2006, 12, 3006; c) L. Xin, K. -S. J. Joshua, F. D. Toste, Angew.
Chem. Int. Ed. 2007, 46, 7671; Angew. Chem. 2007, 119, 7815; d) A.
Fürstner, A. Schlecker, Chem. - Eur. J. 2008, 14, 9181; e) A. S. K.
Hashmi, M. Rudolph, Chem. Soc. Rev. 2008, 37, 1766; f) L. Cui, L. M.
Zhang, Sci. China: Chem. 2010, 53, 113; g) R. M. Zeldin, F. D. Toste,
Chem. Sci. 2011, 2, 1706; h) C. M. Lemon, P. J. Brothers, B. Boitrel,
Dalton Trans. 2011, 40, 6591; i) W. Chaladaj, M. Corbet, A. Fürstner,
Angew. Chem. Int. Ed. 2012, 51, 6929; Angew. Chem. 2012, 124, 7035;
j) H. C. Shen, T. H. Graham, Drug Discov Today Technol 2013, 10, 3;
k) L. Hoffmeister, P. Persich, A. Fürstner, Chem. - Eur. J. 2014, 20,
4396; l) H. G. Raubenheimer, H. Schmidbaur, J. Chem. Educ. 2014, 91,
2024; m) D. Shukla, S. Krishnamurthy, S. V. Sahi, Front Plant Sci 2014,
5, 652; n) L. Hoffmeister, T. Fukuda, G. Pototschnig, A. Fürstner, Chem.
- Eur. J. 2015, 21, 4529; o) A. Homs, M. E. Muratore, A. M. Echavarren,
Org. Lett. 2015, 17, 461; p) J. Carreras, M. S. Kirillova, A. M.
Echavarren, Angew. Chem. Int. Ed. 2016, 55, 7121; Angew. Chem. 2016,
128, 7237; q) A. M. Echavarren, A. S. K. Hashmi, F. D. Toste, Adv.
Synth. Catal. 2016, 358, 1347; r) M. S. Kirillova, M. E. Muratore, R.
Dorel, A. M. Echavarren, J. Am. Chem. Soc. 2016, 138, 3671; s) D.
Nishiyama, A. Ohara, H. Chiba, H. Kumagai, S. Oishi, N. Fujii, H.
Ohno, Org. Lett. 2016, 18, 1670; t) S. Naoe, Y. Yoshida, S. Oishi, N.
Fujii, H. Ohno, J. Org. Chem. 2016, 81, 5690; u) D. Pflaesterer, A. S. K.
Hashmi, Chem. Soc. Rev. 2016, 45, 1331; v) B. Ranieri, C. Obradors, M.
Mato, A. M. Echavarren, Org. Lett. 2016, 18, 1614.
[4] a) W. Rao, Sally, S. N. Berry and P. W. H. Chan, Chem. - Eur. J. 2014,
20, 13174; b) D. Susanti, L.-J. Liu, W. Rao, S. Lin, D.-L. Ma, C.-H.
Leung, P. W. H. Chan, Chem. - Eur. J. 2015, 21, 9111; c) D. B. Huple,
B. D. Mokar, R.-S. Liu, Angew. Chem. Int. Ed. 2015, 54, 14924; Angew.
Chem. 2016, 55, 3253; d) W. Rao, D. Susanti, B. J. Ayers, P. W. H.
Chan, J. Am. Chem. Soc. 2015, 137, 6350; e) D. B. Huple, S. Ghorpade,
R.-S. Liu, Adv. Synth. Catal. 2016, 358, 1348; f) W. Rao, J. W. Boyle, P.
W. H. Chan, Chem. - Eur. J. 2016, 22, 6532; g) S. B. Wagh, Y.-C. Hsu,
R.-S. Liu, ACS Catal. 2016, 6, 7160.
[5] a) A. S. Dudnik, Y. Xia, Y. Li, V. Gevorgyan, J. Am. Chem. Soc. 2010,
132, 7645; b) G. Mazzone, N. Russo, E. Sicilia, J. Chem. Theory
Comput. 2010, 6, 2782; c) R. E. M. Brooner, B. D. Robertson, R. A.
Widenhoefer, Organometallics 2014, 33, 6466; d) T. J. Brown, B. D.
Robertson, R. A. Widenhoefer, J. Organomet. Chem. 2014, 758, 25; e)
R. K. Shiroodi, O. Koleda, V. Gevorgyan, J. Am. Chem. Soc. 2014, 136,
13146.
2015, 51, 13937; g) B. Vulovic, D. Kolarski, F. Bihelovic, R. Matovic,
M. Gruden, R. N. Saicic, Org. Lett. 2016, 18, 3886.
[9] a) B. Crone, S. F. Kirsch, Chem. - Eur. J. 2008, 14, 3514; b) R. Sanz, D.
Miguel, F. Rodriguez, Angew. Chem. Int. Ed. 2008, 47, 7354; Angew.
Chem. 2008, 120, 7464; c) X.-Z. Shu, X.-Y. Liu, K.-G. Ji, H.-Q. Xiao,
Y.-M. Liang, Chem. - Eur. J. 2008, 14, 5282; d) H. Gao, X. Zhao, Y. Yu,
J. Zhang, Chem. - Eur. J. 2010, 16, 456; e) G. Li, Y. Liu, J. Org. Chem.
2010, 75, 3526; f) R. Sanz, D. Miguel, M. Gohain, P. Garcia-Garcia, M.
A. Fernandez-Rodriguez, A. Gonzalez-Perez, O. Nieto-Faza, A. R. de
Lera, F. Rodriguez, Chem. - Eur. J. 2010, 16, 9818; g) W. Li, Y. Li, J.
Zhang, Chem. - Eur. J. 2010, 16, 6447; h) N. Ibrahim, A. S. K. Hashmi,
F. Rominger, Adv. Synth. Catal. 2011, 353, 461; i) W. Li, Y. Li, G. Zhou,
X. Wu, J. Zhang, Chem. - Eur. J. 2012, 18, 15113; j) Y. Yu, W. Yang, F.
Rominger, A. S. K. Hashmi, Angew. Chem. Int. Ed. 2013, 52, 7586;
Angew. Chem. 2013, 125, 7735; k) M. Zhang, J. Zhang, Isr. J. Chem.
2013, 53, 911; l) Y. Qiu, C. Fu, X. Zhang, S. Ma, Chem. - Eur. J. 2014,
20, 10314; m) Q. Zhou, Y. Li, J. Am. Chem. Soc. 2014, 136, 1505; n) L.
Jin, Y. Wu, X. Zhao, J. Org. Chem. 2015, 80, 3547; o) F. Rekhroukh, R.
Brousses, A. Amgoune, D. Bourissou, Angew. Chem. Int. Ed. 2015, 54,
1266; Angew. Chem. 2015, 127, 1282; p) X. Zhang, Z. Geng, RSC Adv.
2016, 6, 62099; q) Y.-Q. Gu, P.-P. Zhang, J.-K. Fu, S. Liu, Y. Lan, J.-X.
Gong, Z. Yang, Adv. Synth. Catal. 2016, 358, 1392.
[10] K. Wittstein, K. Kumar, H. Waldmann, Angew. Chem. Int. Ed. 2011, 50,
9076; Angew. Chem. 2011, 123, 9242.
[11] For selected reviews, see: a) L. Yu, R. Guo, Org. Prep. Proced. Int.
2011, 43, 209; b) A. Brandi, S. Cicchi, F. M. Cordero, A. Goti, Chem.
Rev. 2014, 114, 7317; c) L. Yu, M. Liu, F. Chen, Q. Xu, Org. Biomol.
Chem. 2015, 13, 8379.
[12] For recent contributions from our group and others, see: a) M. Shi, B.
Xu, J.-W. Huang, Org. Lett. 2004, 6, 1175; b) J. Brabec, J. Pittner, J.
Phys. Chem. A 2006, 110, 11765; c) L.-X. Shao, B. Xu, J.-W. Huang, M.
Shi, Chem. - Eur. J. 2006, 12, 510; d) M. Shi, L.-P. Liu, J. Tang, J. Am.
Chem. Soc. 2006, 128, 7430; e) A. Fürstner, C. Aiessa, J. Am. Chem.
Soc. 2006, 128, 6306; f) M. Shi, M. Jiang, L.-P. Liu, Org. Biomol. Chem.
2007, 5, 438; g) B. Hu, S. Xing, Z. Wang, Org. Lett. 2008, 10, 5481; h)
B. Hu, J. Zhu, S. Zing, J. Fang, D. Du, Z. Wang, Chem. - Eur. J. 2009,
15, 324; i) H. Taniguchi, T. Ohmura, M. Suginome, J. Am. Chem. Soc.
2009, 131, 11298; j) M. Jiang, M. Shi, Org. Lett. 2010, 12, 2606; k) K.
Chen, Z. Zhang, Y. Wei, M. Shi, Chem. Commun. 2012, 48, 7696; l) M.
Shi, J.-M. Lu, Y. Wei, L.-X. Shao, Acc. Chem. Res. 2012, 45, 641; m) T.
Kippo, K. Hamaoka, I. Ryu, J. Am. Chem. Soc. 2013, 135, 632; n) K.
Chen, Z.-Z. Zhu, Y.-S. Zhang, X.-Y. Tang, M. Shi, Angew. Chem. Int.
Ed. 2014, 53, 6645; Angew. Chem. 2014, 126, 6763; o) Z.-Z. Zhu, K.
Chen, L.-Z. Yu, X.-Y. Tang, M. Shi, Org. Lett. 2015, 17, 5994; p) T.
Ohmura, H. Taniguchi, M. Suginome, ACS Catal. 2015, 5, 3074; q) Z.
Zhu, K. Chen, Q. Xu, M. Shi, Adv. Synth. Catal. 2015, 357, 3081; r) K.
Chen, X.-Y. Tang, M. Shi, Chem. Commun. 2016, 52, 1967; s) K. Chen,
Z.-Z. Zhu, J.-X. Liu, X.-Y. Tang, Y. Wei, M. Shi, Chem. Commun. 2016,
52, 350.
[13] F. Kleinbeck, F. D. Toste, J. Am. Chem. Soc. 2009, 131, 9178.
[14] a) C. Nieto-Oberhuber, P. M. Munoz, E. Bunuel, C. Nevado, D. J.
Cardenas, A. M. Echavarren, Angew. Chem., Int. Ed. 2004, 43, 2402;
Angew. Chem. 2004, 116, 2456; b) M.-Y. Lin, A. Das, R.-S. Liu, J. Am.
Chem. Soc. 2006, 128, 9340; c) Q. Zhou, Y. Li, J. Am. Chem. Soc. 2014,
136, 1505.
[15] a) S. A. Gawade, S. Bhunia, R.-S. Liu, Angew. Chem., Int. Ed. 2012, 51,
7835; Angew. Chem. 2012, 124, 7955; b) S. N. Karad, S. Bhunia, R.-S.
Liu, Angew. Chem., Int. Ed. 2012, 57, 8122; Angew. Chem. 2012, 124,
8852; c) R. L. Sahani, R.-S. Liu, Chem. Commun. 2016, 52, 7482.
[16] W. Fang, X.-Y. Tang, M. Shi, RSC Adv. 2016, 6, 40474.
[6] a) A. W. Sromek, M. Rubina, V. Gevorgyan, J. Am. Chem. Soc. 2005,
127, 10500; b) R. Kazem Shiroodi, A. S. Dudnik, V. Gevorgyan, J. Am.
Chem. Soc. 2012, 134, 6928; c) J. Jiang, C. Hou, S. Zhang, Z. Luan, C.
Zhao, Z. Ke, J. Org. Chem. 2015, 80, 1661; d) P. Noesel, V. Mueller, S.
Mader, S. Moghimi, M. Rudolph, I. Braun, F. Rominger, A. S. K.
Hashmi, Adv. Synth. Catal. 2015, 357, 500.
[7] a) S. Boussert, I. Diez-Perez, M. J. Kogan, E. de Oliveira, E. Giralt, ACS
Nano 2009, 3, 3091; b) H. V. Adcock, T. Langer, P. W. Davies, Chem. -
Eur. J. 2014, 20, 7262; c) Y. Tokimizu, S. Oishi, N. Fujii, H. Ohno,
Angew. Chem. Int. Ed. 2015, 54, 7862; Angew. Chem. 2015, 127, 7973.
[8] a) A. S. K. Hashmi, T. M. Frost, J. W. Bats, Org. Lett. 2001, 3, 3769; b)
X. Moreau, J.-P. Goddard, M. Bernard, G. Lemiere, J. M. Lopez-
Romero, E. Mainetti, N. Marion, V. Mouries, S. Thorimbert, L.
Fensterbank, M. Malacria, Adv. Synth. Catal. 2008, 350, 43; c) J. A.
Rodriguez, L. Feria, T. Jirsak, Y. Takahashi, K. Nakamura, F. Illas, J.
Am. Chem. Soc. 2010, 132, 3177; d) Y. Harrak, M. Makhlouf, S. Azzaro,
E. Mainetti, J. M. L. Romero, K. Cariou, V. Gandon, J.-P. Goddard, M.
Malacria, L. Fensterbank, J. Organomet. Chem. 2010, 696, 388; e) T. de
Haro, E. Gomez-Bengoa, R. Cribiu, X. Huang, C. Nevado, Chem. - Eur.
J. 2012, 18, 6811; f) Y.-W. Sun, X.-Y. Tang, M. Shi, Chem. Commun.
[17] a) R. L. LaLonde, B. D. Sherry, E. J. Kang, F. D. Toste, J. Am. Chem.
Soc. 2007, 129, 2452; b) I. Nakamura, T. Sato, M. Terada, Y.
Yamamoto, Org. Lett. 2007, 9, 4081; c) L.-P. Liu, G. B. Hammond,
Chem Asian J 2009, 4, 1230; d) G. Cera, S. Piscitelli, M. Chiarucci, G.
Fabrizi, A. Goggiamani, R. S. Ramon, S. P. Nolan, M. Bandini, Angew.
Chem. Int. Ed. 2012, 51, 9891; Angew. Chem. 2012, 124, 10029; e) W.
Wang, G. B. Hammond, B. Xu, J. Am. Chem. Soc. 2012, 134, 5697; f) Y.
Tang, J. Li, Y. Zhu, Y. Li, B. Yu, J. Am. Chem. Soc. 2013, 135, 18396;
g) A. Zhdanko, M. E. Maier, Organometallics 2013, 32, 2000; h) A.
Zhdanko, M. E. Maier, Angew. Chem. Int. Ed. 2014, 53, 7760; Angew.
Chem. Int. Ed. 2014, 126, 7894; i) D. V. Patil, H. Yun, S. Shin, Adv.
Synth. Catal. 2015, 357, 2622; j) H. Peng, N. G. Akhmedov, Y.-F. Liang,
6
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
N. Jiao, X. Shi, J. Am. Chem. Soc. 2015, 137, 8912; k) A. Zhdanko, M.
E. Maier, ACS Catal. 2015, 5, 5994; l) R. E. M. Brooner, T. J. Brown, M.
A. Chee, R. A. Widenhoefer, Organometallics 2016, 35, 2014; m) L.
Huang, M. Rudolph, F. Rominger, A. S. K. Hashmi, Angew. Chem. Int.
Ed. 2016, 55, 4808; Angew. Chem. 2016, 128, 4888.
Recently, a similar gold-catalyzed [2,3]-sigmatropic rearrangement has
been reported by Prabhu’s group, see: g) S. Rao, K. R. Prabhu, Org. Lett.
2017, 19, 846.
[23] Gaussian 09, revision D.01, M. J. Frisch, G. W. Trucks, H. B. Schlegel,
G. E. Scuseria, M. A. Robb, J. R. Cheeseman, G. Scalmani, V. Barone,
B. Mennucci, G. A. Petersson, H. Nakatsuji, M. Caricato, X. Li, H. P.
Hratchian, A. F. Izmaylov, J. Bloino, G. Zheng, J. L. Sonnenberg, M.
Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T.
Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, J. A. Jr.
Montgomery, J. E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E.
Brothers, K. N. Kudin, V. N. Staroverov, R. Kobayashi, J. Normand, K.
Raghavachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M.
Cossi, N. Rega, N. J. Millam, M. Klene, J. E. Knox, J. B. Cross, V.
Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O.
Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J. W. Ochterski, R. L.
Martin, K. Morokuma, V. G. Zakrzewski, G. A. Voth, P. Salvador, J. J.
Dannenberg, S. Dapprich, A. D. Daniels, O. Farkas, J. B. Foresman, J. V.
Ortiz, J. Cioslowski, D. J. Fox, Gaussian, Inc.: Wallingford, CT, 2009.
[24] (a) E. Cancès, B. Mennucci, J. Tomasi, J. Chem. Phys. 1997, 107, 3032;
(b) B. Mennucci, J. Tomasi, J. Chem. Phys. 1997, 106, 5151.
[18] W. v. E. Doering, W. R. Roth, Tetrahedron 1963, 19, 715.
[19] Y. Wang, M. E. Muratore, Z. Rong, A. M. Echavarren, Angew. Chem.
Int. Ed. 2014, 53, 14022; Angew. Chem. 2014, 126, 14246.
[20] D.-Y. Li, Y. Wei, I. Marek, X.-Y. Tang, M. Shi, Chem. Sci. 2015, 6,
5519.
[21] a) J. Li, X. Liu, D. Lee, Org. Lett. 2012, 14, 410; b) S. Mukherjee, P. N.
Tripathi, S. B. Mandal, Org. Lett. 2012, 14, 4186; c) D. Malhotra, G. B.
Hammond, B. Xu, Top. Curr. Chem. 2015, 357, 1.
[22] For selected reports on the [2,3]-sigmatropic rearrangement with regard
to allylic or propargylic ether oxonium ylide under Rh(II) or Au(I)
catalysis: a) D. M. Hodgson, M. Petroliagi, Tetrahedron: Asymmetry
2001, 12, 877; b) S. Kitagaki, Y. Yanamoto, H. Tsutsui, M. Anada,
Tetrahedron Lett. 2001, 42, 6361; c) N. Shimada, S. Nakamura, M.
Anada, M. Shiro, S. Hashimoto, Chem. Lett. 2009, 38, 488; Z. d) Li, V.
Boyarskikh, J. H. Hansen, J. Autschbach, D. G. Musaev, H. M. L.
Davies, J. Am. Chem. Soc. 2012, 134, 15497; e) J. Fu, H. Shang, Z.
Wang, L. Chang, W. Shao, Z. Yang, Y. Tang, Angew. Chem. Int. Ed.
2013, 52, 4198; Angew. Chem. 2013, 125, 4292; f) H. Zhang, B. Wang,
H. Yi, Y. Zhang, J. Wang, Org. Lett. 2015, 17, 3322.
[25] (a) J. P. Perdew, K. Burke, M. Ernzerhof, Phys. Rev. Lett. 1996, 77,
3865; (b) J. P. Perdew, K. Burke M., Ernzerhof, Phys. Rev. Lett. 1997,
78, 1396; (c) C. Adamo, V. Barone, J. Chem. Phys. 1999, 110, 6158.
[26] A. V. Marenich, C. J. Cramer, D. G. Truhlar, J. Chem. Phys. B 2009,
113, 6378.
7
This article is protected by copyright. All rights reserved.

10.1002/chem.201700600
Chemistry - A European Journal
Gold Catalysis
Wei Fang, Yin Wei, Xiang-Ying Tang, and
Min Shi* __________ Page – Page
Gold(I)-catalyzed cycloisomerization of
ortho-
(propargyloxy)arenemethylenecycloprop
anes controlled by adjacent substituent
at aromatic rings
We have developed a new strategy for the cycloisomerization along with
carbon
skeleton
migration
of
ortho-
(propargyloxy)arenemethylenecyclopropanes to attain migration products of
methylenecyclopropane and intramolecular cycloisomerization products in good
to excellent yields upon gold catalysis along with an asymmetric variant to give
the product in an enantiomerically enriched manner.
8
This article is protected by copyright. All rights reserved.