Specific Z-Selectivity in the Oxidative Isomerization of Allyl Ethers to Generate Geometrically Defined Z-Enol Ethers Using a Cobalt(II)(salen) Complex Catalyst

Article abstract of DOI:10.1021/acs.joc.0c00004

Enol ether structural motifs exist in many highly oxygenated biologically active natural products and pharmaceuticals. The synthesis of the geometrically less stable Z-enol ethers is challenging. An efficient Z-selective oxidative isomerization process of allyl ethers catalyzed by a cobalt(II) (salen) complex using N-fluoro-2,4,6-trimethylpyridinium trifluoromethanesulfonate (Me₃NFPY?OTf) as an oxidant has been developed. Thermodynamically less stable Z-enol ethers were prepared in excellent yields with high geometric control. This methodology also demonstrates the effectiveness in controlling the Z-selective isomerization reaction of diallyl ethers at room temperature. This catalytic system provides an alternative pathway to extend the traditional reductive isomerization of allyl ethers.

Full text of DOI:10.1021/acs.joc.0c00004

Subscriber access provided by UNIV OF WESTERN ONTARIO
Article
Specific Z-Selectivity in the Oxidative Isomerization
of Allyl Ethers to Generate Geometrically Defined Z-
Enol Ethers using a Cobalt(II)(salen) Complex Catalyst
Guanxin Huang, Miaolin Ke, Yuan Tao, and Fener Chen
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.0c00004 • Publication Date (Web): 25 Mar 2020
Downloaded from pubs.acs.org on March 26, 2020
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a service to the research community to expedite the dissemination
of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in
full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully
peer reviewed, but should not be considered the official version of record. They are citable by the
Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore,
the “Just Accepted” Web site may not include all articles that will be published in the journal. After
a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web
site and published as an ASAP article. Note that technical editing may introduce minor changes
to the manuscript text and/or graphics which could affect content, and all legal disclaimers and
ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or
consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W.,
Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 9
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
Specific Z-Selectivity in the Oxidative Isomerization of Allyl
Ethers to Generate Geometrically Defined Z-Enol Ethers using
a Cobalt(II)(salen) Complex Catalyst
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
a,b
a,b
a,b
a,b,c
Guanxin Huang, Miaolin Ke, Yuan Tao, and Fener Chen*
a. Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University.
Shanghai 200433, P. R. China.
b. Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Molecules. Shanghai 200433, P. R. China.
c. Institute of Pharmaceutical Science and Technology, Zhejiang University of Technology, 18 Chao Wang Road, Hangzhou
3
10014 China.
Supporting Information Placeholder
3
2
3
1 OR
or
OR
O
Cobalt(II)(salen) complex
2
1
.
N
O
N
O
Me3NFP OTf, (Me2SiH)2O
or
Co
O
O
PhCF3 , r.t
O
tBu
tBu
R
R
tBu
tBu
Co(II)-d
(E)-starting materials
(Z)-enol ethers
up to 90% yield; Z:E > 99:1
mild reaction conditions
wide substrate scope
ABSTRACT: Enol ether structural motifs exist in many highly oxygenated biologically active natural products and
pharmaceuticals. The synthesis of the geometrically less stable Z-enol ethers is challenging. An efficient Z-selective oxidative
isomerization of allyl ethers catalyzed by
a
cobalt(II)(salen) complex using N-fluoro-2,4,6-trimethylpyridinium
trifluoromethanesulfonate (Me NFPY•OTf) as an oxidant has been developed. Thermodynamically less stable Z-enol ethers were
3
prepared in excellent yields with high geometric control. This methodology also demonstrates the effectiveness in controlling the Z-
selective isomerization reaction of diallyl ethers at room temperature. This catalytic system provides an alternative pathway to
extend the traditional reductive isomerization of allyl ethers.
different. In general, the copper (I or II)-catalyzed carbon–
oxygen Ullmann coupling of sp2-hybridized halides with
oxygen-centered nucleophiles is perceived as a possible
solution to circumvent the poor stereoselectivity observed in
the aforementioned methods. The use of inexpensive copper
salts as the catalyst make the Ullmann coupling strategy an
Introduction
Enol ethers are stable, electron-rich π-bonds that are
excellent substrates for the incorporation of oxygen
functionalities. They are commonly employed in a large
number of valuable synthetic transformations, such as the
Claisen rearrangement, isoxazoline synthesis, cycloaddition,
1
2
3
attractive alternative to synthesize E-enol ethers with high
4
5
Diels-Alder reaction, Nazarov cyclization, and cross aldol
1
5
stereospecificity. However, the drawback to this protocol is
the need to heat the reaction, which could be problematic for
sensitive substrates or some functional groups.
6
reaction.
In addition, enol ethers are important
pharmacophores in a variety of bioactive natural products,
which display antidiarrheal, antibiotic, antihypertensive,
hypoglycemic and antalgic properties.7–9 (Figure 1).
Structure−activity relationship studies have demonstrated the
necessity of the enol ether group and a specific enol ether
geometry. Both E- and thermodynamically disfavored Z-enol
ethers are widely found in pharmaceutically active molecular
scaffolds in drug discovery. A large number of strategies for
the construction of enol ether substructures have been
developed to identify an efficient synthetic route to prepare
these compounds, including the Wittig olefination of
1
0
11
lactones, Julia olefination with alkoxysulfones, and the
1
2
13
elimination of β-halo ethers, β- hydroxy ethers, and β-halo
1
4
acetals. However, these methods exhibit poor Z/E selectivity
unless the steric demand of the substituents are substantially
ACS Paragon Plus Environment

The Journal of Organic Chemistry
This is not surprising, as reports on the highly stereoselective
Page 2 of 9
HO
H
H
O
H
O
O
MeO
HO
1
2
3
4
5
6
7
8
9
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
transition metal-catalyzed isomerization of allyl ethers to give
the thermodynamically less stable stereospecific Z-enol ether
products are notably absent. There are only four reports
describing the selective formation of the thermodynamically
O
O
O
HO
HO
OH
OH
N
H
OH
OH
Gardenoside
HO
O
anticancer
OH
Catalpol
hypoglycemic
OMe
less stable Z-enol ether product (Z/E >99:1) using transition-
16a, 16b
Sinomenine
antalgic
metal catalysis.
However, this is limited to only a few
examples bearing little functionality. In addition, there are no
reports on generating high order Z-dienol ethers with
exceptional geometric control via the transition metal-
catalyzed isomerization of allyl ethers.
OMe
N
N
OH
O
N
O
HN
O
O
O
O
O
OH
O
MeO
N
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
OH
Table 1. Optimization of the reaction conditions.a
N
HO
HO
Cobalt catalyst (3 mol%)
Olmesartan Medoxomil
antihypertensive
Bafilomycin A1
antibitic
O
.
O
Me3NFP OTf (2 equiv)
1a
H donor (2 equiv)
solvent , r.t
2a
Figure 1. Natural products and pharmaceuticals containing enol
ether scaffolds
Entry
Catalyst
H donor
Solvent
Yield (%)
b
Z/E
c
1
2
3
4
5
6
7
8
9
Co(III)-a
Co(III)-b
Co(III)-c
Co(III)-a
Co(III)-a
Co(III)-a
Co(II)-a
Co(II)-b
Co(II)-c
Co(II)-d
Co(II)-d
Co(II)-d
Co(II)-d
Co(II)-d
Co(II)-d
(Me
(Me
(Me
(Me
(Me
(Me
(Me
(Me
(Me
(Me
2
2
2
2
2
2
2
2
2
2
SiH)
SiH)
SiH)
SiH)
SiH)
SiH)
SiH)
SiH)
SiH)
SiH)
2
2
2
2
2
2
2
2
2
2
O
O
O
O
O
O
O
O
O
O
toluene
toluene
toluene
THF
-
-
-
-
-
-
-
-
-
-
-
-
The catalytic isomerization of an allyl ether is a simple and
atom-economical process, which is very important in the
synthesis of enol ethers using transition-metal catalysts in both
the research laboratory and large-scale industrial applications.
However, this catalytic isomerization reaction is
thermodynamically favorable and gives an E/Z mixture of the
enol ether isomer with the E-isomer formed as the
predominant thermodynamic product (Scheme 1a). High Z -
selective isomerization of allyl ethers in the presence of
stoichiometric amounts of strong bases have been reported
acetone
PhCF
PhCF
PhCF
PhCF
PhCF
PhCF
PhCF
3
3
3
3
3
3
3
25d
33e
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
31
87(80)f
1
6
1
1
1
0
1
2
PhSiH
Ph SiH
PhSiH (OiPr)
3
84
67
22
40
37
2
3
17
(Scheme 1b).
13
14g
15h
PhCF3
2
Previous work
(Me
(Me
2
SiH)
SiH)
2
O
O
PhCF
PhCF
3
(a) Transition metal catalyzted isomerization of mono-allyl ethers
Transition metal
2
2
3
O
O
aUnless otherwise noted, all the reactions were carried out using 1a (0.3 mmol), Co(II)-d (3
R
R
mol%), Me
atmosphere at room temperature for
determined using GC-MS.
3
NFPY•OTf (2.0 equiv), and (Me
2
SiH)
2
O (2.0 equiv) in PhCF
3
(3 mL) under a
h. The yield and Z/E selectivity were
The reaction time was 7 h. The
O (1.0
E-isomer predominant
b,c
N
2
3
Transition metal
O
d
The reaction time was 5 h.
e
f
R
O
R
g
h
isolated yield is provided in the parentheses. Me
equiv).
3
NFPY•OTf (1.0 equiv). (Me
2
SiH)
2
only a few examples
(
b) Base promoted isomerization of mono-allyl ethers
stoichiometric
amounts of base
O
R
O
N
O
N
O
N
O
N
O
R
Co
Cl
Co
(
Z)
3-100% yield
95% Z isomer
R2
R2
R2
R2
8
>
R1
R1
R1
R1
(
c) Base promoted isomerization of diallyl ethers
Co(III)
Co(II)
stoichiometric
amounts of base
O
O
Co(II)-a: R =H, R =H
R
O
O
Co(III)-a: R =H, R =H
1
2
1
2
R
t
t
Co(III)-b: R = Bu, R =Me
Co(II)-b: R = Bu, R =Me
1 2
1
2
(
Z, Z)
00% yield with 3 examples
>99:1 (Z, Z)
d) Ru complex catalyzted isomerization of diallyl ethers
t
t
Co(III)-c: R= Bu, R = Bu
Co(II)-c: R =Br, R =Br
1 2
2
1
t
t
Co(II)-d:R = Bu, R = Bu
1
2
(
Table 2. Substrate scope of the allyl ether used in the
a
isomerization reaction.
O
O
Ru complex
R
O
O
R
Co(II)-d (3 mol%)
mixture of E,Z-
isomers
R1
.
R
R
O
Me3NFP OTf (2 equiv)
O
No reported yields and selectivities
1 R1
(Me2SiH)2O (2 equiv)
PhCF3 (0.1 M), rt
This work
2
Cobalt(II)(salen) catalyzted oxidative isomerization of mono-allyl ethers
and diallyl ethers
cobalt(II)(salen)
Yield (%)b
Z/Ec
Entry
Product
Time (h)
O
complex
O
Z
R
R
1
O
3
80
>99:1
cobalt(II)(salen)
complex
2a
O
O
O
O
R
R
OMe
(Z, Z)
2
3
6
5
82
84
>99:1
>99:1
MeO
BnO
O
O
Scheme 1. Challenges in the isomerization of mono-allyl
ethers and diallyl ethers.
2b
However, the transition metalcatalyzed
transformations of allyl ethers suffer from a poor Z/E-
stereoisomer selectivity or a narrow substrate scope.
Z -selective
2c
2,16b,16d,18
ACS Paragon Plus Environment

Page 3 of 9
The Journal of Organic Chemistry
hydrogen donor, respectively. Unfortunately, almost no
1
2
3
4
5
6
7
8
9
4
5
O
6
5
81
79
>99:1
>99:1
reaction occurred at room temperature in a range of diverse
solvents (Table 1, entry 1-6). Switching to a class of
Co(II)(R,R-salen) catalysts was crucial to achieving the
oxidative isomerization and surprisingly gave the
thermodynamically less stable Z-enol ether 2a using Co(II)-a-
Co(II)-c with excellent geometric selectivity (Z/E >99:1)
albeit in very poor yield (entries 7–9). To our delight, this
oxidative isomerization gave the desired product 2a in 87%
yield and >99:1 Z-selectivity using the Co(II)-d catalyst (entry
2
d
MeO
O
2
e
6
5
88
>99:1
O
2f
1
0). Subsequently, different silanes were tested as the
hydrogen donor in the reaction (entries 11–13). Isomerization
of 1a using PhSiH and Ph SiH was successful at room
7
8
9
35
3
72
78
75
>99:1
>99:1
>99:1
O
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
2g
3
2
2
temperature and the reaction was completed within 3 h,
resulting in Z-enol ether 2a in 84% and 67% yield,
respectively (entries 11 and 12). However, employing
F3C
Cl
O
2
h
5
2
PhSiH (OiPr) gave 2a in 22% yield (entry 13). The selectivity
O
2i
observed for the conversion of 1a to 2a was always excellent
(>99:1). Attempts to reduce the amount of oxidant and
hydrogen donor used in the reaction caused a significant
decrease in the product yield (entries 14, 15).
Cl
10
5
74
>99:1
Cl
O
O
2j
Having established the optimized reaction conditions, the
scope of the isomerization reaction was examined. All the
aromatic allyl ether derivatives studied were cleanly converted
to the thermodynamically less stable Z-enol ether product in
high yield (74–88%) with excellent stereospecificity (>99:1)
(Table 2, entries 2–14). A steric bulky substituent, such as 2,6-
dimethylphenyl allyl ether 1g was used, the Z-product still be
favoured with good yield and >99:1 Z/E but longer reaction
time than other aromatic allyl ethers. The cobalt-catalyzed
isomerization of aliphatic allyl ethers 1o and 1p was also
investigated (entries 15 and 16). Remarkably, the double bond
was selectively isomerized to afford the desired products (2o
and 2p) in 53% and 59% yield, respectively. Importantly,
sterically hindered allyl ether 1q bearing a menthol group
required a longer reaction time to complete the isomerization
reaction and gave 2q in 90% with exclusive Z-selectivity
(entry 17). The result reveals that steric hindrance has a
significant effect on the rate of the isomerization reaction.
Interestingly, double bond migration in 1q (>99% ee)
proceeded well without any loss of optical purity. 1,1-
disubstituted allyl ether 1r could still be convered to
corresponding enol ether 2r with excellent yield (entry 18).
Excellent functional group tolerance was observed in table 2
when different allyl ethers were subjected to the reaction
conditions bearing methyl, trifluoromethyl, methyoxy,
benzyloxy, tert-butyl, halides and so on.
11
5
5
79
83
>99:1
>99:1
Br
Br
2k
12
O
2
l
Br
1
3
4
5
4
74
78
>99:1
>99:1
O
m
2
1
O
2
n
Ph
O
1
5
6
7
7
53
59
>99:1
>99:1
2
o
C15H31
O
1
2
p
1
7d
16
8
90
>99:1
O
2
q
18
81
-
O
2
r
aUnless otherwise noted, all the reactions were carried out using 1 (0.3 mmol), Co(II)-d
3 mol%), Me NFPY•OTf (2.0 equiv), and (Me SiH) O (2.0 equiv) in anhydrous PhCF
under atmosphere at room temperature. The isolated yield after column
chromatography. The Z/E selectivity was determined using H NMR spectroscopy. The ee
of 2q was >99%.
(
3
2
2
b
3
a
N
2
c
1
d
Results and Discussion
Cobalt-catalyzed Z-selective alkene isomerization has been
1
9
Co(II)-d (3 mol%)
reported by Hilt et al. Herein, we report a novel and general
cobalt-catalyzed oxidative isomerization reaction for the
synthesis of Z-enol ethers with excellent geometric selectivity.
This methodology displays excellent functional group
tolerance, uses a commercially available catalyst, and can be
performed under mild reaction conditions. The catalytic
system works well for not only the Z-selective isomerization
of allyl ethers, but also the Z-selective isomerization of diallyl
ethers.
O
O
O
Me3NFP OTf (2 equiv)
.
+
(Me SiH) O (2 equiv)
2
2
MeO
MeO
MeO
PhCF3 (0.1 M), rt

1s
2s
73.4% yield
2s
trace
Co(II)-d (3 mol%)
.
Me3NFP OTf (2 equiv)
TBSO
TBSO
(Me SiH) O (2 equiv)
2
2
1t
PhCF3 (0.1 M), rt
2t
61% yield
E/Z=1.5:1
Co(II)-d (3 mol%)
.
Me3NFP OTf (2 equiv)
OPh
no reaction
(Me2SiH)2O (2 equiv)
PhCF3 (0.1 M), rt
1u
We began our study on the isomerization of allyl ether 1a
using
a
series of Co(III)(R,R-salen)Cl catalysts with
SiH) O acting as the oxidant and
Me NFPY•OTf and (Me
3
2
2
Scheme 2. Limitation of this method.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 4 of 9
Nevertheless, our developed method also contains
The results of the isomerization reactions are summarized
in Table 3. We were pleased to find that these reactions
worked well in the presence of Co(II)-2d (3 mol%) using 4
1
2
3
4
5
6
7
8
9
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
limitations (Scheme 2). When homoallyl ether 1s was
subjected to the standard reaction conditions, only trace
amount of the isomerized product 2s was observed. Instead,
the bicyclic compound 2s’ was isolated as the major product.
The isomerization of the higher alkenyl ether 1t was also
investigated, furnishing the isomerized product 2t in 61%
yield. The E/Z selectivity was rather poor, with the E-isomer
being slightly favored. Finally, no isomerization reaction
happened to compound 1u, which contains a methyl group
attaching to the terminal carbon of the double bond.
equiv of Me
3
NFPY•OTf as the oxidant and 4 equiv of
at room
(
Me SiH) O as the hydrogen donor in PhCF
2
2
3
temperature. The isomerization reaction clearly shows high
geometric selectivity in all cases to give the corresponding (Z,
Z)-dienol ether products in good to excellent yield. It is
noteworthy that aliphatic diallyl ethers (4d-j) (Table 3, entries
4
–10) isomerized much faster than aromatic diallyl ethers (4a-
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
a
c) (entries 1-3). As chiral catalyst were applied, we also
investigated asymmetric desymmetrisation for 3f, but no
Table 3. Isomerization of diallyl ethers.
Co(II)-d (3 mol%)
1
.
mono-isomerization product was found through GCMS and H
Me3NFP OTf (4 equiv)
O
O
O
O
R
3
NMR under all the time-points. We speculate that the rate of
isomerization is the same on both sides.
Deuterium labelling experiment has been done. We used
(Me2SiH)2O (4 equiv)
R
4
PhCF3 (0.1 M), rt
b
Z/Ec
Entry
Product
Time (h)
Yield (%)
1
9
83
>99:1
PhSiD
3
(D=99.5%) as the H source to conduct the
O
O
O
isomerization of 1n under the standard reaction conditions,
resulting in deuterium incorporation exclusively at the
terminal carbon (Scheme 3).
4
a
2
3
10
9
82
78
>99:1
>99:1
O
O
Cl
4b
Co(II)-d (3 mol%)
O
.
Me3NFP OTf (2 equiv)
4c
O
PhSiD3 (2 equiv)
PhCF3 (0.1 M), rt
O
CH2D
1n
d-2n
31% yield, >99:1 Z/E
4
5
6
7
8
9
5
4
5
6
5
6
74
75
81
77
86
86
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
O
O
Scheme 3. Mechanistic study.
4
d
Based on the above results, a plausible reaction pathway for
the cobalt-catalyzed isomerization reaction is shown in
Scheme 4. Initially, the catalytic cycle begins with the
generation of a Co(III)−F complex and cationic Co(III)OTf
complex in the presence of Me NFPY•OTf. Transformation of
3
the Co(III)−F complex to the Co(III)-H complex occurs due
O
O
O
O
O
O
4e
4
f
to the strong F-Si bonding energy, which has been reported by
4
g
21
22
Shigehisa and Holland et al. The Co(III)-H coordinates
with the allyl ether to form a cis-conformation. Formation of
similar cis-conformation via the coordination of Pt-H and Ru-
O
O
4
h
23
H has been reported previously. Subsequently, the key
O
O
O
radical intermediate B generated via single electron transfer. B
is subsequently oxidized by the cationic Co(III)OTf complex
to form key carbocation intermediate C with the release of
cobalt(II) complex . Finally, trans-coplanar elimination of the
proton in C occurs to form the desired Z-vinyl ether 2 with the
release of the second cobalt(II) complex.
6
4
i
O
O
1
0
O
7
83
>99:1
4j
aUnless otherwise noted, all the reactions were carried out using 3 (0.3 mmol), Co-II-d (3
mol%), Me NFPY•OTf (4.0 equiv), and (Me SiH) O (4.0 equiv) in anhydrous PhCF under
a N atmosphere at room temperature. Isolated yield after column chromatography. The
3
2
2
3
b
c
2
OTf
1
H
Z/E selectivity was determined using H NMR spectroscopy.
H
H
O
H
N
F
Si
Si
OR
A
cis conformation
To the best of our knowledge, the previously reported
isomerization reactions of diallyl ethers form the dienol ether
products as the (Z, Z)-isomer using stoichiometric amounts of
H
H
F-Co(III)
H
O
2Co(II)
H-Co(III)
Co
III)
R
(
Co (III) OTf
1
7a, 17b
strong bases (Scheme 1c)
and as mixture of E, Z-isomers
H
F
1
8g, 20
O
using Ru complex catalysts (Scheme 1d), respectively.
Si
Si
However transition meal-catalyzed exclusive (Z, Z)-selective
translocation of various diallyl ethers has been rarely reported
to date, which is especially noteworthy. Therefore, we turned
our attention to investigating whether diallyl ethers could be
selectively isomerized into the thermodynamically less stable
N
H
H
H
H
H
H
H
H
H
-HOTf
H
H
O
OR
H
O
OTf
Co
(II)
R
Co
R
2
Co(II)
(II)
C
Co(II)
B
Scheme 4. Proposed catalytic cycle for the oxidative
isomerization reaction.
(
Z, Z)-isomer.
ACS Paragon Plus Environment

Page 5 of 9
The Journal of Organic Chemistry
In summary, the oxidative isomerization of allyl ethers to Z-
enol ethers has been developed based on carbon radicals and
(Z)-1-methyl-3-(prop-1-en-1-yloxy)benzene (2d): purified by
1
2
3
4
5
6
7
8
9
column chromatography (petroleum ether). Colorless oil;
1
actual mass 36.0 mg, yield 81%. (Z: E >99:1). H NMR (400
carbocation species as key intermediates using
cobalt(II)(salen) complex, Me NFPY•OTf, and (Me SiH)
a
O.
MHz, CDCl
3
): δ 7.24-7.20 (m, 1H), 6.89-6.83 (m, 3H), 6.40
3
2
2
(
(
1
9
dd, J= 4.8, 1.5 Hz, 1H), 4.91-4.88 (m, 1H), 2.37 (s, 3H), 1.75
The reaction was found to tolerate a wide variety of functional
groups and exhibited excellent yields and selectivity (Z/E
99:1). This methodology also works well for the Z-selective
isomerization reaction of diallyl ethers at room temperature.
1
3
1
dd, J= 6.8, 1.6 Hz, 3H). C{ H} NMR (100 MHz, CDCl
3
): δ
57.6, 141.0, 139.7, 129.3, 123.2, 117.0, 113.2, 107.3, 21.5,
.4. (Only Z isomer is visible).
>
+
HRMS (EI-TOF): calcd.for C10
found: 148.0887.
H12O (M ) m/z: 148.0888,
EXPERIMENTAL SECTION
General Information: Thin-layer chromatography (TLC)
carried out on 0.25 mm silica gel platesvisualized with UV
light and/or by staining with ethanolic phosphomolybdic acid
(PMA) or iodine. Flash column chromatography was
performed on silica gel (300-400 mesh). NMR spectraswere
recorded on Bruker AM400 (400 MHz). Chemical shifts (δ)
are given in ppm relative to TMS, coupling constants (J) in
Hz. Optical rotations were taken on JASCO P1020. High-
resolution mass spectra were recorded on Bruker ApeXIII 7.0
TESLA FTMS.
(Z)-1-methoxy-4-(prop-1-en-1-yloxy)benzene (2e): purified
by column chromatography (petroleum ether/ethyl acetate =
30/1). Colorless oil; actual mass 38.9 mg, yield 79%. (Z: E
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
>99:1). H NMR (400 MHz, CDCl ): δ 6.98-6.96 (m, 2H),
3
6.88-6.86 (m, 2H), 6.34 (dd, J= 6.2, 1.9 Hz, 1H), 4.86-4.80
1
3
1
(m, 1H), 3.80 (s, 3H), 1.77 (dd, J= 6.8, 1.3 Hz, 3H). C{ H}
NMR (100 MHz, CDCl ): δ 155.1, 151.8, 142.0, 117.4, 114.7,
3
106.2, 55.6, 9.4. (Only Z isomer is visible).
1
6b
This product is known.
(Z)-1-(tert-butyl)-4-(prop-1-en-1-yloxy)benzene (2f): purified
General Procedure for the Cobalt-catalyzed Allyl Ethers
Isomerization: A Schlenk tube was charged with Co(II)-d
by column chromatography (petroleum ether). Colorless oil;
1
actual mass 50.2 mg, yield 88%. (Z:E >99:1). H NMR (400
(5.4 mg, 0.009 mmol, 3% equiv), Me
3
NFPY•OTf (173.5 mg,
MHz, CDCl ): δ 7.44-7.42 (m, 2H), 7.05-7.03 (m, 2H), 6.47
3
0.6 mmol, 2 equiv), after being dried in vacuo for 3 mins,
degassed trifluorotoluene (3 mL) was added. The solution was
(dd, J= 5.8, 1.4 Hz, 1H), 4.96-4.93 (m, 1H), 1.83 (dd, J= 6.9,
1
3
1
1.3 Hz, 3H), 1.42 (s, 9H). C{ H} NMR (100 MHz, CDCl ): δ
3
bubbled with N
mmol, 1 equiv) and (Me
was added under N . The resulting mixture was stirred at rt for
hours. After 1a was completely consumed as monitored by
2
for three times, after which 1a (40.2 mg, 0.3
155.5, 145.2, 141.3, 126.4, 115.8, 107.0, 34.3, 31.6, 9.5. (Only
2
SiH) O (80.6 mg, 0.6 mmol, 2 equiv)
2
Z isomer is visible).
HRMS (EI-TOF): calcd.for C H O (M ) m/z: 190.1358,
+
2
13 18
5
found: 190.1359.
TLC, H
2
O (5 mL) was added to quench the reaction. The
(Z)-1,3-dimethyl-2-(prop-1-en-1-yloxy)benzene (2g): purified
by column chromatography (petroleum ether). Colorless oil;
resulted mixture was then extracted three times with diethyl
ether (10 mL × 3). The combined organic layer was dried over
1
actual mass 35.0 mg, yield 72%. (Z:E >99:1). H NMR (400
Na
2
SO
4
. After evaporation of the volatile solvent under
MHz, CDCl ): δ 7.09-7.07 (m, 2H), 7.04-7.00 (m, 1H), 6.03
3
reduced pressure, the residue was purified by flash
chromatography on silica gel to afford pure 2a (32.2 mg, 0.25
mmol) as a colourless oil in a yield of 80%.
(dd, J= 6.0, 1.7 Hz, 1H), 4.69-4.62 (m, 1H), 2.32 (s, 6H), 1.85
13
1
(dd, J= 6.9, 1.6 Hz, 3H). C{ H} NMR (100 MHz, CDCl ): δ
3
154.7, 144.6, 130.8, 128.8, 124.5, 102.3, 16.2, 9.2. (Only Z
(
Z)-(prop-1-en-1-yloxy)benzene (2a): purified by column
isomer is visible).
This product is known.
1
8d
chromatography (petroleum ether). Colorless oil; actual mass
1
3
2.2 mg, yield 80%. (Z: E > 99:1). H NMR (400 MHz,
CDCl ): δ 7.38-7.34 (m, 2H), 7.10-7.05 (m, 3H), 6.44 (dd, J=
.0, 1.5 Hz, 1H), 4.94 (m, 1H), 1.79 (dd, J= 6.9, 1.5 Hz, 3H).
(Z)-1-(prop-1-en-1-yloxy)-3-(trifluoromethyl)benzene (2h) :
purified by column chromatography (petroleum ether).
Colorless oil; actual mass 47.3 mg, yield 78%. (Z: E
3
6
1
3
1
1
C{ H} NMR (100 MHz, CDCl
3
): δ 157.6, 141.0, 129.6,
>99:1). H NMR (400 MHz, CDCl ): δ 7.44-7.40 (m, 1H),
3
1
22.4, 116.2, 107.5, 9.4. (Only Z isomer is visible). This
7.30-7.28 (m, 1H), 7.24 (m, 1H), 7.18-7.16 (m, 1H), 6.38 (dd,
17a
product is known.
J= 6.1, 1.7 Hz, 1H), 5.00 (m, 1H), 1.72 (dd, J= 6.9, 1.6 Hz,
13
1
(
Z)-1,3-dimethoxy-5-(prop-1-en-1-yloxy)benzene
(2b):
3H). C{ H} NMR (100 MHz, CDCl ): δ 157.6, 140.1, 130.1,
3
purified by column chromatography (petroleum ether/ethyl
119.4, 119.0, 119.0, 118.9, 118.9, 113.0, 113.0, 113.0, 112.9,
acetate = 30/1). Colorless oil; actual mass 47.8 mg, yield 82%.
109.3, 9.4.
1
+
(
1
1
Z: E > 99:1). H NMR (400 MHz, CDCl
3
): δ 6.35 (dd, J= 5.9,
HRMS (EI-TOF): calcd.for C H F O (M ) m/z: 202.0605,
10
9 3
.5 Hz, 1H), 6.18-6.17 (m, 3H), 4.88 (m, 1H), 3.77 (s, 6H),
found: 202.0608.
(Z)-1-chloro-4-(prop-1-en-1-yloxy)benzene (2i): purified by
1
3
1
.71 (dd, J= 6.9, 1.6 Hz, 3H). C{ H} NMR (100 MHz,
): δ 161.5, 159.4, 140.6, 107.9, 94.9, 55.4, 9.4. (Only Z
CDCl
3
column chromatography (petroleum ether). Colorless oil;
1
isomer is visible).
HRMS (EI-TOF): calcd. for C11
found: 194.0949.
actual mass 37.9 mg, yield 75%. (Z: E >99:1). H NMR (400
+
H
14
O
3
(M ) m/z: 194.0943,
MHz, CDCl ): δ 7.26-7.23 (m, 2H), 6.92-6.90 (m, 2H), 6.30
3
(dd, J= 6.0, 1.6 Hz, 1H), 4.91 (m, 1H), 1.71 (dd, J= 6.9, 1.6
13
1
(
Z)-1-(benzyloxy)-4-(prop-1-en-1-yloxy)benzene
(2c):
Hz, 3H). C{ H} NMR (100 MHz, CDCl ): δ 156.2, 140.6,
3
purified by column chromatography (petroleum ether).
Colorless oil; actual mass 60.6 mg, yield 84%. (Z: E > 99:1).
129.5, 127.3, 117.4, 108.3, 9.4. (Only Z isomer is visible).
16b
This product is known.
1
H NMR (400 MHz, CDCl
3
): δ 7.45-7.31 (m, 5H), 6.93 (s,
(Z)-1,3-dichloro-5-(prop-1-en-1-yloxy)benzene (2j): purified
4H), 6.31 (dd, J= 5.9, 1.5 Hz, 1H), 5.04 (s, 2H), 4.85-4.78 (m,
by column chromatography (petroleum ether). Colorless oil;
1
3
1
1
1
H), 1.72 (dd, J= 6.9, 1.6 Hz, 3H). C{ H} NMR (100 MHz,
CDCl ): δ 154.3, 151.9, 141.9, 137.2, 128.6, 128.0, 127.5,
17.3, 115.8, 106.4, 70.7, 9.3. (Only Z isomer is visible).
actual mass 45.1 mg, yield 74%. (Z: E >99:1). H NMR (400
3
MHz, CDCl ): δ 6.55-6.46 (m, 3H), 6.30 (dd, J= 6.2, 1.7 Hz,
3
1
3
1
1
1H), 5.01 (m, 1H), 1.69 (dd, J= 6.9, 1.8 Hz, 3H). C{ H}
+
HRMS (EI-TOF): calcd.for C16
found: 240.1155.
H
16
O
2
(M ) m/z: 240.1150,
NMR (100 MHz, CDCl ): δ 164.9 164.8, 162.5, 139.6, 110.1,
3
ACS Paragon Plus Environment

The Journal of Organic Chemistry
8.9, 99.8, 99.7, 99.6, 98.1, 97.8, 97.5, 9.4. (Only Z isomer is (petroleum ether/ethyl acetate = 30/1). Colorless oil; actual
Page 6 of 9
9
1
1
2
3
4
5
6
7
8
9
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
visible).
HRMS (EI-TOF): calcd.for C
found: 201.9959.
mass 53.0 mg, yield 90%. (Z: E >99:1). H NMR (400 MHz,
CDCl ): δ 6.00 (dd, J= 6.2, 1.4 Hz, 1H), 4.36-4.30 (m, 1H),
+
9
H
8
Cl
2
O (M ) m/z: 201.9952,
3
3.34 (td, J= 10.5, 4.4 Hz, 1H), 2.20-2.12 (m, 1H), 2.00 (m,
1H), 1.67- 1.62 (m, 2H), 1.57 (dd, J= 6.7, 1.4 Hz, 3H), 1.39-
1.32 (m, 2H), 1.01 (q, J= 12.0 Hz, 2H), 0.92-0.90 (m, 7H),
(Z)-1-bromo-3-(prop-1-en-1-yloxy)benzene (2k): purified by
column chromatography (petroleum ether). Colorless oil;
actual mass 50.5 mg, yield 79%. (Z: E >99:1). H NMR (400
1
13
1
3
0.78 (d, J= 6.9 Hz, 3H). C{ H} NMR (100 MHz, CDCl ): δ
MHz, CDCl
3
): δ 7.17-7.15 (m, 3H), 6.96-6.93 (m, 1H), 6.36-
144.8, 100.2, 81.3, 47.9, 41.6, 34.4, 31.6, 25.9, 23.6, 22.2,
6
6
.34 (dd, J= 6.1, 1.5 Hz, 1H), 5.00-4.93 (m, 1H), 1.73 (dd, J=
20.8, 16.4, 9.4. (Only Z isomer is visible).
This product is known.
1
3
1
17a
.9, 1.6 Hz, 3H). C{ H} NMR (100 MHz, CDCl
3
): δ 158.2,
1
40.2, 130.7, 125.4, 122.9, 119.5, 114.9, 108.9, 9.4. (Only Z
2-((2-methylprop-1-en-1-yl)oxy)naphthalene (2r): purified by
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
16b
isomer is visible).This product is known.
(Z)-1-bromo-4-(prop-1-en-1-yloxy)benzene (2l): purified by
column chromatography (petroleum ether). Colorless oil;
actual mass 53.1 mg, yield 83%. H NMR (400 MHz, CDCl
δ 7.40 (d, J= 8.6 Hz, 2H), 6.88 (d, J= 8.7 Hz, 2H), 6.37 (dd, J=
6
3
1
column chromatography (petroleum ether). Colorless oil;
1
actual mass 48.2 mg, yield 81%. H NMR (400 MHz, CDCl
3
):
δ 7.82-7.76 (m, 3H), 7.50-7.37 (m, 2H), 7.29-7.26 (m, 2H),
1
13
1
3
):
6.39 (s, 1H), 1.82 (s, 3H), 1.80 (s, 3H). C{ H} NMR (100
MHz, CDCl ): δ 155.7, 135.1, 134.5, 129.6, 127.7, 126.9,
3
.4, 1.6 Hz, 1H), 4.95-4.90 (m, 1H), 1.73 (dd, J= 6.9, 1.3 Hz,
126.5, 124.0, 118.6, 118.3, 109.4, 19.6, 15.3. This product is
1
3
1
24
H). C{ H} NMR (100 MHz, CDCl
3
): δ 156.7, 140.5, 132.4,
known.
17.9, 114.7, 108.5, 9.4. (Only Z isomer is visible).This
6-methoxy-4-methylchroman (2s’): purified by column
1
6b
product is known.
chromatography (petroleum ether). Colorless oil; actual mass
1
(Z)-1-bromo-2-(prop-1-en-1-yloxy)benzene (2m): purified by
39.2 mg, yield 73%. H NMR (400 MHz, CDCl
3
): δ 6.74-6.66
column chromatography (petroleum ether). Colorless oil;
actual mass 47.3 mg, yield 74%. (Z: E >99:1). H NMR (400
MHz, CDCl ): δ 7.57 (dd, J= 8.1, 1.5 Hz, 1H), 7.26 (td, J= 7.4,
(m, 3H), 4.17-4.11 (m, 2H), 3.76 (s, 3H), 2.94-2.93 (m, 1H),
1
2.11-2.04 (m, 1H), 1.74-1.70 (m, 1H), 1.33 (d, 3H, J = 6.8
21a
3
Hz). This product is known.
1.5 Hz, 1H), 6.98 (dd, J= 8.2, 1.2 Hz, 1H), 6.92 (td, J= 7.9, 1.3
tert-butyl(hept-5-en-1-yloxy)dimethylsilane (2t): Colorless
1
Hz, 1H), 6.35 (dd, J= 6.5, 1.6 Hz,, 1H), 5.00 (m, 1H), 1.77
oil; actual mass 41.8 mg, yield 61%. (E:Z =1.5:1). H NMR
dd, J= 6.8, 1.5 Hz, 3H). 13C{ H} NMR (100 MHz, CDCl
1
): δ
(
3
3
(400 MHz, CDCl ): δ 5.43-5.40 (m, 2H), 3.63-3.58 (m, 2H),
1
54.1, 140.5, 133.6, 128.5, 123.5, 115.9, 112.5, 109.1, 9.5.
2.10-2.02 (m, 2H), 1.64-1.55 (m, 5H), 0.89 (s, 9H), 0.04 (s,
1
6b
13
(Only Z isomer is visible). This product is known.
6H). C NMR (100 MHz, CDCl
3
): δ 131.0 (E), 130.2 (Z),
(Z)-2-(prop-1-en-1-yloxy)naphthalene (2n): purified by
125.0 (E), 124.2 (Z), 62.7, 32.7, 28.8 (Z), 26.0 (E), 23.1, 18.4
1
6h
column chromatography (petroleum ether). Colorless oil;
actual mass 43.1 mg, yield 78%. (Z: E >99:1). H NMR (400
(Z), 17.9 (E), 12.7, -5.3. This product is known.
1
1,3-bis((Z)-prop-1-en-1-yloxy)benzene (4a): purified by
column chromatography (petroleum ether/ethyl acetate =
30/1). Colorless oil; actual mass 47.4 mg, yield 83%. (Z: E
MHz, CDCl
H), 7.46 (t, J= 7.1 Hz, 1H), 7.37 (t, J= 7.3 Hz, 1H), 7.29-7.24
m, 2H), 6.53-6.62 (m, 1H), 5.00-4.95 (m, 1H), 1.77 (dd, J=
3
): δ 7.79 (d, J= 8.5 Hz, 2H), 7.74 (d, J= 8.2 Hz,
1
(
1
>99:1). H NMR (400 MHz, CDCl
3
): δ 7.26-7.22 (m, 1H),
1
3
1
6.9, 1.5 Hz, 3H). C{ H} NMR (100 MHz, CDCl
140.8, 134.3, 129.8, 129.7, 127.7, 127.0, 126.5, 124.2, 118.6,
10.1, 108.1, 9.5. (Only Z isomer is visible).
3
): δ 155.4,
6.71-6.68 (m, 3H), 6.39-6.38 (m, 2H), 4.95-4.89 (m, 2H), 1.73
1
3
1
3
(dd, J= 6.8, 1.3 Hz, 6H). C{ H} NMR (100 MHz, CDCl ): δ
1
158.7, 140.6, 130.1, 110.0, 108.0, 104.4, 9.4. (Only Z isomer
+
HRMS (EI-TOF): calcd.for C13
found: 184.0884.
H
12O (M ) m/z: 184.0888,
is visible).
HRMS (EI-TOF): calcd.for C12
found: 190.0989.
+
H
14
O
2
(M ) m/z: 190.0994,
(Z)-(4-(prop-1-en-1-yloxy)butyl)benzene (2o): purified by
column chromatography (petroleum ether). Colorless oil;
actual mass 30.3 mg, yield 53%. (Z: E >99:1). H NMR (400
MHz, CDCl
2-chloro-1,3-bis((Z)-prop-1-en-1-yloxy)benzene
(4b):
1
purified by column chromatography (petroleum ether/ethyl
acetate = 30/1). Colorless oil; actual mass 55.3 mg, yield 82%.
3
): δ 7.37-7.33 (m, 2H), 7.27-7.23 (m, 3H), 6.00
1
(dd, J= 6.3, 1.7 Hz, 1H), 4.49-4.42 (m, 1H), 3.80 (t, J= 6.5 Hz,
(Z: E >99:1). H NMR (400 MHz, CDCl
3
): δ 7.11 (t, J= 8.3
2
H), 2.72 (t, J= 7.5 Hz, 2H), 1.84-1.71 (m, 4H), 1.67 (dd, J=
Hz, 1H), 6.69 (d J= 8.2 Hz, 2H), 6.33 (dd, J= 5.8, 1.4 Hz, 2H),
1
3
1
13
1
7.0, 1.8 Hz, 3H). C{ H} NMR (100 MHz, CDCl
142.4, 128.5, 128.4, 125.8, 100.9, 71.9, 35.7, 29.5, 27.8, 9.3.
Only Z isomer is visible).
3
): δ 145.7,
5.00-4.95 (m, 2H), 1.74 (dd, J= 6.8, 1.6 Hz, 6H). C{ H}
NMR (100 MHz, CDCl ): δ 154.5, 140.5, 127.0, 109.6, 109.3,
3
(
9.5. (Only Z isomer is visible).
HRMS (EI-TOF): calcd.for C12
found: 224.0598.
+
+
HRMS (EI-TOF): calcd.for C13
found: 190.1362.
H
18O (M ) m/z: 190.1358,
2
H13ClO (M ) m/z: 224.0604,
(Z)-1-(prop-1-en-1-yloxy)hexadecane (2p): purified by
1,4-bis((Z)-prop-1-en-1-yloxy)benzene (4c): purified by
column chromatography (petroleum ether/ethyl acetate =
column chromatography (petroleum ether). Colorless oil;
actual mass 50.0 mg, yield 59%. (Z: E >99:1). H NMR (400
MHz, CDCl
3
1
NMR (100 MHz, CDCl
29.8, 29.7, 29.6, 29.6, 29.4, 29.4, 25.9, 22.7, 14.1, 9.2. (Only
Z isomer is visible).
HRMS (EI-TOF): calcd.for C19
found: 282.2929.
1
30/1). Colorless oil; actual mass 44.5 mg, yield 78%. (Z: E
1
3
): δ 5.94 (dd, J= 6.3, 1.5 Hz, 1H), 4.36 (m, 1H),
>99:1). H NMR (400 MHz, CDCl
3
): δ 6.96 (m, 4H), 6.33 (dd,
.71 (t, J= 6.7 Hz, 2H), 1.64-1.62 (m, 2H), 1.58 (dd, J= 7.0,
J= 6.2, 1.8 Hz, 2H), 4.88-4.82 (m, 2H), 1.74 (dd, J= 6.8, 1.4
13
1
13
1
.4 Hz, 3H), 1.27 (m, 26H), 0.89 (t, J= 6.6 Hz, 3H). C{ H}
): δ 145.6, 100.7, 72.1, 32.0, 29.8,
Hz, 6H). C{ H} NMR (100 MHz, CDCl
3
): δ 153.0, 141.6,
3
117.3, 106.8, 9.4. (Only Z isomer is visible).
+
HRMS (EI-TOF): calcd.for C12
found: 190.0999.
14 2
H O (M ) m/z: 190.0994,
+
H
38O (M ) m/z: 282.2923,
1,2-bis((Z)-prop-1-en-1-yloxy)ethane (4d) ： purified by
column chromatography (petroleum ether/ethyl acetate =
30/1). Colorless oil; actual mass 31.6 mg, yield 74%. (Z: E
(1S,2R,4R)-1-isopropyl-4-methyl-2-((Z)-prop-1-en-1-
yloxy)cyclohexane (2q): purified by column chromatography
1
3
>99:1). H NMR (400 MHz, CDCl ): δ 5.96 (dd, J= 6.1, 1.5
ACS Paragon Plus Environment

Page 7 of 9
The Journal of Organic Chemistry
Hz, 2H), 4.45-4.38 (m, 2H), 3.89 (s, 4H), 1.58 (dd, J= 6.8, 1.6
1,3-bis(allyloxy)-2-chlorobenzene (3b) ： Method A: Allyl
1
3
1
1
2
3
4
5
6
7
8
9
Hz, 6H). C{ H} NMR (100 MHz, CDCl
): δ 145.5, 101.7,
3
bromide (7.86 mL, 90.89 mmol) was slowly added to a stirred
solution of 2-chlorobenzene-1,3-diol (3.3 g, 22.73 mmol) and
K CO (9.4 g, 68.15 mmol) in dry DMF (22 mL) kept at room
70.9, 9.2. (Only Z isomer is visible).
+
8 14 2
HRMS (EI-TOF): calcd.for C H O (M ) m/z: 142.0994,
2
3
found: 142.0997.
temperature under nitrogen with stirring. After 20 h the
1
,3-bis((Z)-prop-1-en-1-yloxy)propane (4e): purified by
column chromatography (petroleum ether/ethyl acetate =
0/1). Colorless oil; actual mass 35.1 mg, yield 75%. (Z: E
mixture was diluted with H O, until dissolution of the
2
precipitate, and washed with ether (3 x 100 mL). The
3
>
combined extracts were washed with H O (8 x 200 mL), brine
2
1
99:1). H NMR (400 MHz, CDCl
3
): δ 5.96 (dd, J= 6.1, 1.5
(200 mL) and dried over Na SO . The solvent was removed
2
4
Hz, 2H), 4.45-4.38 (m, 2H), 3.85 (t, J= 6.2 Hz, 4H), 1.98-1.92
under reduced pressures to give 4b (4.95 g, 97%) as a yellow
13
1
1
(
m, 2H), 1.60 (dd, J= 6.8, 1.6 Hz, 6H). C{ H} NMR (100
oil without further purification. H NMR (400 MHz, CDCl ): δ
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
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
MHz, CDCl
3
): δ 145.5, 101.2, 68.3, 30.3, 9.2. (Only Z isomer
7.11 (t, J= 8.4 Hz, 1H), 6.58 (d, J= 8.3 Hz, 2H), 6.11-6.02 (m,
2H), 5.46 (dd, J= 17.2, 1.5 Hz, 2H), 5.30 (dd, J= 10.5, 1.4 Hz,
is visible).
+
13
1
HRMS (EI-TOF): calcd.for C10
found: 156.1151.
H
18
O
2
(M ) m/z: 156.1150,
2H), 4.61-4.60 (m, 4H). C{ H} NMR (100 MHz, CDCl ): δ
3
155.4, 132.8, 126.9, 117.8, 106.4, 69.9.
(
Z)-1-(2-methyl-3-((Z)-prop-1-en-1-yloxy)propoxy)prop-1-
HRMS (EI-TOF): calcd.for C H ClO (M ) m/z: 224.0604,
+
12 13
2
ene (4f): purified by column chromatography (petroleum
ether/ethyl acetate = 30/1). Colorless oil; actual mass 41.4 mg,
yield 81%. (Z: E >99:1). H NMR (400 MHz, CDCl
5
found: 224.0609.
3-(3-(allyloxy)-2-methylpropoxy)prop-1-ene (3f): Method B:
The starting alcohol (1.8 g, 20 mmol) was dissolved in dry
THF (50 ml) under an atmosphere of nitrogen at 0°C. To this
solution was added sodium hydride (2.4 g, 60 mmol) and was
allowed to stir for 10 minutes at 0°C. After adding allyl
bromide (7.3 g, 60 mmol), the solution was then allowed to
stir at room temperature for 30 minutes and reflux overnight.
The reaction was quenched by the addition of saturated
ammonium chloride solution. The mixture was then extracted
with diethyl ether three times and the organic phase was
1
3
): δ 5.96-
.94 (m, 2H), 4.41-4.36 (m, 2H), 3.74-3.70 (m, 2H), 3.67-3.63
(
(
m, 2H), 2.15-2.08 (m, 1H), 1.60 (dd, J= 6.8, 1.6 Hz, 6H), 1.00
d, J= 6.8 Hz, 3H). C{ H} NMR (100 MHz, CDCl
13
1
3
): δ
1
45.9, 100.9, 73.7, 34.7, 13.7, 9.2. (Only Z isomer is visible).
+
HRMS (EI-TOF): calcd.for C
found: 170.1311.
9 16 2
H O (M ) m/z: 170.1307,
(Z)-1-(2,2-dimethyl-3-((Z)-prop-1-en-1-yloxy)propoxy)prop-
-ene (4g): purified by column chromatography (petroleum
ether/ethyl acetate = 30/1). Colorless oil; actual mass 42.6 mg,
1
washed with water, brine and dried over Na SO . After
2
4
1
yield 77%. (Z: E >99:1). H NMR (400 MHz, CDCl
3
): δ 5.95
evaporation of the volatile solvent under reduced pressure, the
residue was purified by flash chromatography(petroleum
ether/ethyl acetate = 30/1) on silica gel to afford pure 3f
(
(
dd, J= 6.1, 1.4 Hz, 2H), 4.36-4.20 (m, 2H), 3.52 (s, 4H), 1.58
dd, J= 6.8, 1.5 Hz, 6H), 0.96 (s, 6H). C{ H} NMR (100
): δ 146.5, 100.2, 77.5, 37.0, 21.7, 9.2. (Only Z
1
3
1
MHz, CDCl
3
(2.59g, 76.0%,) as a colourless oil. H NMR (400 MHz,
1
isomer is visible).
HRMS (EI-TOF): calcd.for C11
found: 184.1460.
1,1-bis(((Z)-prop-1-en-1-yloxy)methyl)cyclopropane
purified by column chromatography (petroleum ether/ethyl
CDCl ): δ 5.94-5.85 (m, 2H), 5.25 (d, J= 17.5 Hz, 2H), 5.14
3
+
H
20
O
2
(M ) m/z: 184.1463,
(d, J= 10.9 Hz, 2H), 3.95 (d, J= 5.2 Hz, 4H), 3.42-3.86 (m,
2H), 3.32-3.28 (m, 2H), 2.07-1.99 (m, 1H), 0.95 (s, 3H).
(4h):
13C{
1
H} NMR (100 MHz, CDCl ): δ 135.1, 116.5, 72.8, 72.0,
3
34.3, 14.5.
HRMS (EI-TOF): calcd.for C H O (M ) m/z: 170.1307,
acetate = 30/1). Colorless oil; actual mass 47.0 mg, yield 86%.
+
10 18
2
1
(Z: E >99:1). H NMR (400 MHz, CDCl
3
): δ 5.97 (dd, J= 6.1,
found: 170.1311.
1,1-bis((allyloxy)methyl)cyclopropane (3h): (Method B: the
synthesis method is the same as 3f): purified by column
chromatography (petroleum ether/ethyl acetate
Colorless oil; actual mass 2.6 g, yield 71.1%. H NMR (400
1
1
1
.6 Hz, 2H), 4.38-4.35 (m, 2H), 3.66 (s, 4H), 1.59 (dd, J= 6.8,
1
3
1
.6 Hz, 6H), 0.55 (s, 4H). C{ H} NMR (100 MHz, CDCl
3
): δ
46.0, 100.9, 74.9, 21.3, 9.2, 8.3. (Only Z isomer is visible).
= 30/1).
+
1
HRMS (EI-TOF): calcd.for C11
found: 182.1311.
1
column chromatography (petroleum ether/ethyl acetate =
30/1). Colorless oil; actual mass 47.4 mg, yield 86%. (Z: E
H
18
O
2
(M ) m/z: 182.1307,
MHz, CDCl ): δ 5.90-5.84 (m, 2H), 5.22 (dd, J= 17.1, 1.5 Hz,
3
,6-bis((Z)-prop-1-en-1-yloxy)hexane (4i): purified by
2H), 5.11 (dd, J= 10.3, 1.1 Hz, 2H), 3.95 (d, J= 5.5 Hz, 4H),
3.33 (s, 4H), 0.46 (s, 4H). 13C{
1
H} NMR (100 MHz, CDCl3):
δ 135.1, 116.6, 73.6, 71.8, 20.7, 8.5.
HRMS (EI-TOF): calcd.for C H O (M ) m/z: 182.1307,
1
+
>99:1). H NMR (400 MHz, CDCl
Hz, 2H), 4.37-4.33 (m, 2H), 3.70 (t, J= 6.5 Hz, 4H), 1.64-1.60
3
): δ 5.91 (dd, J= 6.3, 1.6
1
0
18
2
found: 170.1307.
(
m, 4H), 1.56 (dd, J= 6.9, 1.4 Hz, 6H), 1.41-1.38 (m, 4H).
4,7,10,13-tetraoxahexadeca-1,15-diene (3j): (Method B: the
synthesis method is the same as 3f): Colorless oil; actual
mass 3.1 g, yield 67.4%. purified by column chromatography
1
3
1
C{ H} NMR (100 MHz, CDCl
3
): δ 145.6, 100.8, 71.9, 29.7,
2
5.6, 9.2. (Only Z isomer is visible). This product is
1
7a
1
known.
(petroleum ether/ethyl acetate = 30/1). H NMR (400 MHz,
(2Z,14Z)-4,7,10,13-tetraoxahexadeca-2,14-diene
(4j):
CDCl ): δ 5.93-5.84 (m, 2H), 5.24 (d, J= 17.0, 2H), 5.14 (d, J=
3
purified by column chromatography (petroleum ether/ethyl
acetate = 30/1). Colorless oil; actual mass 57.1 mg, yield 83%.
10.3, 2H), 4.00 (d, J= 5.3, 4H), 3.64-3.62 (m, 8H), 3.58-3.56
(m, 4H). 13C{
1
H} NMR (100 MHz, CDCl ): δ 134.7, 117.1,
3
1
(
Z: E >99:1). H NMR (400 MHz, CDCl
3
): δ 5.95 (dd, J= 6.2,
72.2, 70.6, 69.4.
HRMS (EI-TOF): calcd.for C H O (M ) m/z: 230.1518,
1.6 Hz, 2H), 4.37-4.34 (m, 2H), 3.85 (t, J= 4.9 Hz, 4H), 3.67-
+
1
2
22
4
1
3
1
3.64 (m, 8H), 1.54 (dd, J= 6.9, 1.4 Hz, 6H). C{ H} NMR
(100 MHz, CDCl ): δ 145.6, 101.3, 71.3, 70.8, 70.4, 9.2.
Only Z isomer is visible).
found: 230.1515.
Synthesis of PhSiD325: LiAlD4 (1.2 g, 31.22 mmol) was
3
(
mixed with dry Et O (100 ml) and cooled to 0 C in an ice
o
2
+
HRMS (EI-TOF): calcd.for C12
found: 230.1522.
H
22
O
4
(M ) m/z: 230.1518,
bath. Trichlorophenylsilane (2.5 ml, 15.61 mmol) was added
slowly to the above suspension in a drop wise manner. After
the addition the reaction mixture was brought to room
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 8 of 9
temperature and refluxed for 24 h. The solvent was evacuated
and PhSiD was distilled into a cold trap.
PhSiD : (D=99.5%) Colorless oil; actual mass1.25 g, yield
74.0%. H NMR (400 MHz, CDCl
1
(a) Jeon, H.; Chung, Y.; Kim, S. Proline Ester Enolate Claisen
1
2
3
4
5
6
7
8
9
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
Rearrangement and Formal Total Synthesis of (−)-Cephalotaxine.
J. Org. Chem. 2019, 84, 8080. (b) Ziegler, F. E. Stereo- and
Regiochemistry of the Claisen Rearrangement: Applications to
Natural Products Synthesis. Acc. Chem. Res. 1977, 10, 227. (c)
Martín Castro, A. M. Claisen Rearrangement over the Past Nine
Decades. Chem. Rev. 2004, 104, 2939. (d) Zieg-ler, F. E. The
Thermal, Aliphatic Claisen Rearrangement. Chem. Rev. 1988, 88,
3
3
1
3
): δ 7.66-7.64 (m, 2H),
.48-7.39 (m, 3H). 1 C NMR (101 MHz, CDCl
): δ 136.3,
30.3, 128.6.
3
7
1
3
Deuterium labelling experiment: A Schlenk tube was
charged with Co(II)-d (5.4 mg, 0.009 mmol, 3% equiv),
1
423.
Me
dried in vacuo for 3 mins, degassed trifluorotoluene (3 mL)
was added. The solution was bubbled with N for three times,
after which 1n (55.3 mg, 0.3 mmol, 1 equiv) and PhSiD (66.7
mg, 0.6 mmol, 2 equiv) was added under N . The resulting
mixture was stirred at rt for 4 hours. After 1n was completely
consumed as monitored by TLC, H O (5 mL) was added to
3
NFPY•OTf (173.5 mg, 0.6 mmol, 2 equiv), after being
2
3
Krompiec, S.; Bujak, P.; Szczepankiewicz, W. Convenient
Synthesis of Isoxazolines via Tandem Isomerization of Allyl
Compounds to Vinylic Derivatives and 1,3-Dipolar Cycloaddition
of Nitrile Oxides to the Vinylic Compounds. Tetrahedron Lett.
2008, 49, 6071.
Greene, A. E.; Charbonnier, F. Asymmetric Induction in the
Cycloaddition Reaction of Dichloroketene with Chiral Enol
Ethers. A Versatile Approach to Optically Active Cyclopentenone
Derivatives. Tetrahedron Lett. 1985, 26, 5525.
Nicolaou, K. C.; Snyder, S. A.; Montagnon, T.;
Vassilikogiannakis, G. The Diels-Alder Reaction in Total
Synthesis. Angew. Chem. Int. Ed. 2002, 41, 1668.
(a) Harmata, M.; Lee, D. R.; Barnes, C. L. Stereospecific
Synthesis of Dienones via a Torquoselective Retro-Nazarov
Reaction. Org. Lett. 2005, 7, 1881. (b) He, W.; Herrick, I.;
Atesin, T.; Caruana, P.; Kellenberger, C.; Frontier, A. Polarizing
the Nazarov Cyclization:ꢀ The Impact of Dienone Substitution
Pattern on Reactivity and Selectivity. J. Am. Chem. Soc. 2008,
2
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
3
2
2
quench the reaction. The resulted mixture was then extracted
three times with diethyl ether (10 mL × 3). The combined
organic layer was dried over Na SO . After evaporation of the
2 4
volatile solvent under reduced pressure, the residue was
purified by flash chromatography on silica gel (petroleum
ether) to afford pure d-2n (17.2 mg, 0.17 mmol) as a
colourless oil in a yield of 31.0%.
4
5
(
>
d-2n): Colorless oil; actual mass 17.2 mg, yield 31.0%. (Z: E
99:1). H NMR (400 MHz, CDCl ): δ 7.79 (d, J= 8.5 Hz,
3
1
2H), 7.74 (d, J= 8.2 Hz, 1H), 7.46 (t, J= 7.1 Hz, 1H), 7.37 (t,
J= 7.3 Hz, 1H), 7.29-7.24 (m, 2H), 6.53-6.62 (m, 1H), 5.00-
1
30, 1003.
6
7
8
Kawano, Y.; Fujisawa, H.; Mukaiyama, T. Lithium Acetate-
catalyzed Crossed Aldol Reaction between Aldehydes and
Trimethylsilyl Enolates Generated from Other Aldehydes. Chem.
Lett. 2005, 34, 614.
(a) El-Naggar, L. J.; Beal, J. L. Iridoids. A Review. J. Nat. Prod.
1980, 43, 649. (b) El-Naggar, L. J.; Beal, J. L.; W. Doskotch, R.
Iridoid Glycosides from Mentzelia Decapteala. J. Nat. Prod.
1982, 45, 539.
1
3
1
4
.95 (m, 1H), 1.76-1.74 (m, 2H). C{ H} NMR (100 MHz,
CDCl ): δ 155.4, 140.8, 134.3, 129.8, 129.7, 127.7, 127.0,
26.5, 124.2, 118.6, 110.1, 108.1, 9.2 (t, J= 19.5 Hz). (Only Z
3
1
isomer is visible).
HRMS (EI-TOF): calcd.for C13
found: 185.0951.
+
H11DO (M ) m/z: 185.0951,
Gram scale experiment: A 150 mL Three-necked flask was
charged with Co(II)-d (135.0 mg, 0.225 mmol, 3% equiv),
Klionsky, D. J.; Elazar, Z.; Seglen, P. O.; Rubinsztein, D. C. Does
Bafilomycin A1 Block the Fusion of Autophagosomes with
Lysosomes? Autophagy 2008, 4, 849.
Me
in vacuo for 3 mins, degassed trifluorotoluene (75 mL) was
added. The solution was bubbled with N for three times, after
which 1a (1.005 g, 7.5 mmol, 1 equiv) and (Me SiH) O (2.015
g, 15 mmol, 2 equiv) was added under N . The resulting
mixture was stirred at rt for 5 hours. After 1a was completely
consumed as monitored by TLC, H O (50 mL) was added to
3
NFPY•OTf (4.338 g, 15 mmol, 2 equiv), after being dried
9
1
Perry, C. M. Azilsartan Medoxomil. Clin. Drug Investig. 2012,
2
3
2, 621.
2
2
0 Lakhrissi, M.; Chapleur, Y. Wittig Olefination of Lactones.
Angew. Chem., Int. Ed. Engl. 1996, 35, 750.
2
11 Surprenant, S.; Chan W. Y.; Berthelette, C. Efficient Synthesis of
Substituted Vinyl Ethers Using the Julia Olefination. Org. Lett.
2003, 5, 4851.
12 Mizuno, K.; Kimura, Y.; Otsuji, Y. A Convenient Synthesis of
Aryl Vinyl Ethers by Use of Tetra-n-butylammonium Hydrogen
Sulfate. Synthesis 1979, 9, 688.
13 Pollex A.; Hiersemann, M. Catalytic Asymmetric Claisen
Rearrangement in Natural Product Synthesis:ꢀ Synthetic Studies
toward (−)-Xeniolide F. Org. Lett. 2005, 7, 5705.
2
quench the reaction. The resulted mixture was then extracted
three times with diethyl ether (100 mL × 3). The combined
organic layer was dried over Na SO . After evaporation of the
2 4
volatile solvent under reduced pressure, the residue was
purified by flash chromatography on silica gel to afford pure
2a (663.3 mg, 4.95 mmol) as a colourless oil in a yield of
66%, Z/E >99:1.
1
4 Park, H. G.; Kim, D. H.; Yoo, M. S.; Park, M. K.; Jew, S. S.
Practical Regioselective Synthetic Method for (E)-Enol Ether.
Tetrahedron Lett. 2000, 41, 4579.
ASSOCIATED CONTENT
Supporting Information
15 (a) Whitesides, G. M.; Sadowski J. S.; Lilburn, J. Copper(I)
Alkoxides. Synthesis, Reactions, and Thermal Decompositions. J.
Am. Chem. Soc. 1974, 96, 2829. (b) Keegstra, M. Copper
Catalysed Preparation of Vinyl Ethers from Unactivated Vinylic
Halides. Tetrahedron 1992, 48, 2681. (c) Wan, Z.; Jones, C. D.;
Koenig, T. M.; Pu Y. J.; Mitchell, D. Vinyl Aryl Ethers from
Copper-Catalyzed Coupling of Vinyl Halides and Phenols.
Tetrahedron Lett. 2003, 44, 8257. (d) Nordmann, G.; Buchwald,
S. L. A Domino Copper-Catalyzed C−O Coupling−Claisen
Rearrangement Process. J. Am. Chem. Soc. 2003, 125, 4978.
16 (a) Kuznik N.; Krompiec, S. Transition Metal Complexes as
Catalysts of Double-Bond Migration in O-allyl Systems. Coordin.
Chem. Rev. 2007, 251, 222. (b) Krompiec, S.; Kuznik, N.;
Kuznik, R.; Kuznik J.; Mrowiec-Białon, J. Isomerization of Allyl
Aryl Ethers to Their 1-Propenyl Serivatives Catalysed by
General experimental conditions, NMR spectra, and HPLC
analysis of the products. This material is available free of charge
via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*
E-mail: rfchen@fudan.edu.cn
Notes
Any additional relevant notes should be placed here.
REFERENCES
ACS Paragon Plus Environment

Page 9 of 9
The Journal of Organic Chemistry
Ruthenium Complexes. J. Mol. Catal. A Chem. 2004, 219, 29. (c)
Dienes or 2Z,4E-Dienes. Angew. Chem. Int. Ed. 2012, 51, 1270.
(b) Hilt, G. Double Bond Isomerisation and Migration-New
Playgrounds for Transition Metal-Catalysis. ChemCatChem 2014,
6, 2484. (c) Schmidt, A.; Hilt, G. Unprecedented Cobalt-
Catalyzed Isomerization Reactions to Single Skipped 2,4,7-
Trienes Applied in the Synthesis of Urushiol. Chem. Asian J.
2014, 9, 2407.
1
2
3
4
5
6
7
8
9
Manzini, S. J.; Nelson D.; Nolan, S. P. A Highly Active Cationic
Ruthenium Complex for Alkene Isomerisation: AꢀCatalyst for the
Synthesis of High Value Molecules. ChemCatChem 2013, 5,
2
848. (d) Gauthier, D.; Lindhardt, A. T.; Olsen, E. P.; Overgaard
J.; Skrydstrup, T. In Situ Generated Bulky Palladium Hydride
Complexes as Catalysts for the Efficient Isomerization of Olefins.
Selective Transformation of Terminal Alkenes to 2-Alkenes. J.
Am. Chem. Soc. 2010, 132, 7998. (e) Varela-Alvarez, A.; Sordo,
J. A.; Piedra, E.; Nebra, N.; Cadierno, V.; Gimeno, J.
Ruthenium(IV) ‐Catalyzed Isomerization of the C=C Bond of O
20 Morgans, G. L.; Ngidi, E. L.; Madeley, L. G.; Khanye, S. D.;
Michael, J. P.; de Koning, C. B.; van Otterlo, W. A. L. Synthesis
of
Unsaturated
1,4-Heteroatom-Containing
Benzo-Fused
Heterocycles using a Sequential Isomerization Ring-Closing
Metathesis Strategy. Tetrahedron 2009, 65, 10650.
‐
Allylic Substrates: A Theoretical and Experimental Study.
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
Chem. Eur. J. 2011, 17, 10583.
21 (a) Shigehisa, H.; Ano, T.; Homna, H.; Ebisawa, K.; Hiroya, K.
Co-catalyzed Hydroarylation of Unactivated Olefins. Org. Lett.
2016, 18, 3622. (b) Shigehisa, H.; Aoki, T.; Yamaguchi, S.;
Shimizu N.; Hiroya, K. Hydroalkoxylation of Unactivated Olefins
with Carbon Radicals and Carbocation Species as Key
Intermediates. J. Am. Chem. Soc. 2013, 135, 10306. (c) Shigehisa,
H.; Koseki, N.; Shimizu, N.; Fujisawa, M.; Niitsu, M.; Hiroya, K.
Catalytic Hydroamination of Unactivated Olefins Using a Co
Catalyst for Complex Molecule Synthesis. J. Am. Chem. Soc.
2014, 136, 13534. (d) Shigehisa, H.; Hayashi, M.; Ohkawa, H.;
Suzuki, T.; Okayasu, H.; Mukai, M.; Yamazaki, A.; Kawai, R.;
Kikuchi, H.; Satoh, Y.; Fukuyama, A.; Hiroya, K. Catalytic
17 (a) Su, C.; Williard, P. G.; Isomerization of Allyl Ethers Initiated
by Lithium Diisopropylamide. Org. Lett. 2010, 12, 5378. (b)
Krompiec, S.; Marcol, B.; Zych, D.; Kurpanik, A.; Danikiewicz,
W.; Matussek, M.; Kuznik, N. Crown Ether Base: Highly Active,
Regioselective and Reusable Catalytic Systems for Double Bond
Migration in Allylic Compounds. ChemistrySelect 2017, 2, 6717;
(c) Ma, Y.; Algera, R. F.; Collum, D. B. Sodium
Diisopropylamide in N,N-Dimethylethylamine: Reactivity,
Selectivity, and Synthetic Utility. J. Org. Chem. 2016, 81, 11312.
(d) Krompiec, S.; Bujak, P.; Malarz, J. Krompiec, M.; Skorka,
L.; Pluta, T.; Danikiewicz, W.; Kania, M.; Kusz, J. An
isomerization—1,3-dipolar Cycloaddition Tandem Reaction
Towards the Synthesis of 3-aryl-4-methyl-5-O-Substituted
Isoxazolines from O-Allyl Compounds. Tetrahedron 2012, 68,
Synthesis
of
Saturated
Oxygen
Heterocycles
by
Hydrofunctionalization of Unactivated Olefins: Unprotected and
Protected Strategies. J. Am. Chem. Soc. 2016, 138, 10597. (e)
Shigehisa, H.; Nishi, E.; Fujisawa M.; Hiroya, K. Cobalt-
Catalyzed Hydrofluorination of Unactivated Olefins: A Radical
Approach of Fluorine Transfer. Org. Lett. 2013, 15, 5158.
6
018. (e) Price, C. C.; Snyder, W. H. Solvent Effects in the Base-
Catalyzed Isomerization of Allyl to Propenyl Ethers. J. Am.
Chem. Soc. 1961, 83, 1773. (f) Wojtowicz J. A.; Polak, R. J. 3-
Substituted Oxetanes. J. Org. Chem. 1973, 38, 2061.
22 (a) Ding, K.; Dugan, T. R.; Brennessel, W. W.; Bill, E.; Holland,
P. L. Synthesis, Properties, and Reactivity of Diketiminate-
Supported Cobalt Fluoride Complexes. Organometallics 2009,
28, 6650. (b) Dugan, T. R.; Goldberg, J. M.; Brennessel, W. W.;
Holland, P. L. Low-Coordinate Cobalt Fluoride Complexes:
Synthesis, Reactions, and Production from C-F Activation
Reactions. Organometallics 2012, 31, 1349.
23 (a) Larionov, E.; Li, H. H.; Mazet, C. Well-defined Transition
Metal Hydrides in Catalytic Isomerizations. Chem. Commun.,
2014, 50, 9816. (b) Clark, H. C.; Kurosawa, H. Chemistry of
Metal Hydrides. XV. Mechanism of Double-Bond Migration
Induced by Platinum(II) Hydrides. Inorg. Chem., 1973, 12,
1566. (c) Sato, T.; Komine, N.; Hirano, M.; Komiya, S.;
Selective Isomerization of 2-Allylphenol to (Z)-2-
18 (a) Lv, Z. N.; Chen, Z. Q.; Hu, Y.; Zheng, W. R.; Wang, H. B.;
Mo, W. L.; Yin, G. C. A General Strategy for Open-Flask
Alkene Isomerization by Ruthenium Hydride Complexes with
Non
‐Redox Metal Salts. ChemCatChem 2017, 9, 3849. (b)
Weber, F.; Schmidt, A.; Röse, P.; Fischer, M.; Burghaus O.; Hilt,
G. Double-Bond Isomerization: Highly Reactive Nickel Catalyst
Applied in the Synthesis of the Pheromone (9Z,12Z)-Tetradeca-
9
,12-dienyl Acetate. Org. Lett. 2015, 17, 2952. (c) Mamone, P.;
Grunberg, M. F.; Fromm, A.; Khan, B. A.; Gooßen, L. J. [Pd(μ-
t
2
Br)(P Bu3)] as a Highly Active Isomerization Catalyst: Synthesis
of Enol Esters from Allylic Esters. Org. Lett. 2012, 14, 3716. (d)
Wang, H. B.; Liu, S. D.; Sun, T. T.; Lv, Z. N.; Zhan, Z.; Yin, G.
C.; Chen, Z. Q. Lewis acid promoted double bond migration in
O-allyl to Z-products by Ru-H complexes. Mol. Catal. 2019, 463,
3
Propenylphenol Catalyzed by Ru(cod)(cot)/PEt . Chem. Lett.
1
0. (e) Krompies, S.; Kuznik, N.; Bieg, T.; Adamus, B.; Maznusz,
1999, 28, 441.
J.; Grymel, M. Isomerization of allylaryl ethers catalyzed by
ruthenium complexes. Pol. J. Chem. 2000, 74, 1197. (f)
Krompiec, S.; Kuznik, N.; Urbala, M.; Rzepa, J. Isomerization of
alkyl allyl and allyl silyl ethers catalyzed by ruthenium
complexes. J. Mol. Catal. A Chem. 2006, 248, 198.
24 Giedyk, M.; Turkowska,J.; Lepak, S.; Marculewicz, M.;
Proinsias, K.; Gryko, D. Photoinduced Vitamin B12-Catalysis for
Deprotection of (Allyloxy)arenes. Org. Lett. 2017, 19, 2670.
25 Kumar, A.; Pandiakumar, A. K.; Samuelson, A. G. Titanium
promoted reduction of imines with Grignards, silanes, and zinc:
identification of a new mechanism with silanes. Tetrahedron
2004, 70, 3185.
1
9 (a) Pünner, F.; Schmidt, A.; Hilt, G. Up the Hill: Selective Double
‐
Bond Isomerization of Terminal 1,3-Dienes towards Z-1,3-
ACS Paragon Plus Environment