Aerobic Allylation of Alcohols with Non-Activated Alkenes Enabled by Light-Driven Selenium-π-Acid Catalysis

Article abstract of DOI:10.1055/s-0037-1609938

A new organocatalytic protocol for the aerobic dehydrogenative allylation of alcohols using non-activated alkenes as the allylating reagent and ambient air as the terminal oxidant is established. Mechanistically, the procedure relies on the interplay of a diselane and a photoredox catalyst by means of a light-induced electron transfer process. Under optimized conditions, a broad range of both cyclic and acyclic ethers is accessed with very high functional group tolerance and excellent regioselectivity.

Full text of DOI:10.1055/s-0037-1609938

SYNTHESIS
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© Georg Thieme Verlag Stuttgart · New York
2018, 50, A–K
feature
A
en
K. Rode et al.
Feature
Synthesis
Aerobic Allylation of Alcohols with Non-Activated Alkenes
Enabled by Light-Driven Selenium-π-Acid Catalysis
Katharina Rodea
non-activated
alcohol function
Martina Palombab
Stefan Ortgiesa
Rene Riegera
= selenium cat.
Se
OH
O
Se
hν
= photoredox cat.
hν
(
)
( )
n
n
air (oxidant)
LED light (465 nm)
allylic ethers
39–99% yield
non-activated
alkenes
Alexander Breder*a
0
0
0
0
0-
0
0
3
4-
8
9
9
5-
9
1
9
a Institut für Organische und Biomolekulare Chemie, Universität Göttingen,
Tammannstr. 2, D-37077 Göttingen, Germany
broad functional group tolerance
high regioselectivity
29 examples
sustainable conditions
abreder@gwdg.de
b Department of Pharmaceutical Sciences, Faculty of Pharmacy, University
of Perugia, Via Fabretti, 48 - 06123 Perugia, Italy
Received: 05.06.2018
Accepted after revision: 06.08.2018
Published online: 23.08.2018
gen.8 From an environmental and atom-economic view-
point,9 the use of O2 is particularly appealing due to the
low-polluting profile of its reduction by-products (i.e., H2O
and H2O2). Despite the fact that aerobic allylic etherifica-
tions of alcohols with simple alkenes—in particular cata-
lyzed by palladium complexes—have experienced substan-
tial progress and reached remarkable levels of efficiency
over recent years, there are still significant limitations asso-
ciated with these processes. For instance, although the use
of ambient air as a gratuitous reagent would be highly de-
sirable, aerobic Pd-catalyzed alkene etherifications general-
ly require the presence of neat oxygen to maintain a proper
catalytic turnover and to avoid the formation of inactive
Pd(0) species.10,11 In conceptually related reactions, it was
even shown that the use of air led to significantly inferior
results in comparison to pure O2.12 Another critical aspect
concerning intermolecular Pd-catalyzed aerobic allylic
etherifications of alkenes correlates with the substitution
pattern on the olefin. In the cases reported thus far, pre-
dominantly terminal alkenes were presented as suitable
substrates.8,13
Against this background, the demand for alternative
catalytic concepts that allow aerobic etherification reac-
tions to be conducted under an atmosphere of ambient air
and with a broadened scope in terms of internal alkenes be-
comes vividly evident. In this context, selenium-catalyzed
etherifications of alkenes were shown to be sufficiently tol-
erant toward higher substitution patterns on the olefinic
entity.8a,h,14 Irrespective of these important contributions,
the generalized utilization of air as the terminal oxidant in
Se-catalyzed, inter- and intramolecular dehydrogenative al-
lylic etherifications of simple alcohols with alkenes has re-
mained elusive thus far.15 In the course of our research pro-
gram on the design of oxidative alkene functionalizations
catalyzed by selenium-π-acids,16 we recently discovered
that these reactions can be driven by visible light, using
DOI: 10.1055/s-0037-1609938; Art ID: ss-2018-z0389-fa
Abstract A new organocatalytic protocol for the aerobic dehydroge-
native allylation of alcohols using non-activated alkenes as the allylating
reagent and ambient air as the terminal oxidant is established. Mecha-
nistically, the procedure relies on the interplay of a diselane and a
photoredox catalyst by means of a light-induced electron transfer pro-
cess. Under optimized conditions, a broad range of both cyclic and acy-
clic ethers is accessed with very high functional group tolerance and ex-
cellent regioselectivity.
Key words alcohols, allylations, alkenes, oxidations, photoredox catal-
ysis, selenium-π-acids
Ethers play pivotal roles in a number of chemical, bio-
logical, and industrial contexts. In nature, ethers are, inter
alia, found as functional motifs in bioactive substances such
as polyether antibiotics1 or as skeletal elements in lignify-
ing plants.2 In addition, ethers are very frequently encoun-
tered in the realm of technical and medicinal applications.
Representative examples include excipients,3 cosmetics,4
and binders for the production of ceramics.5 Traditional
protocols for the construction of simple non-epoxydic
ethers rely on the redox-neutral conversion of alcohols or
alkoxides with different electrophiles such as alkyl and aryl
halides (e.g., Williamson ether synthesis, Ullmann conden-
sation, Buchwald–Hartwig coupling, etc.).6 An efficient al-
ternative strategy for the formation of ethers under partic-
ularly mild conditions is the catalytic conversion of alcohols
with discrete7 or latent allylic electrophiles.8 In the latter
case, the carbon–carbon double bond of a simple alkene is
directly activated under oxidative conditions in such a way
that it will react with an unactivated alcohol to furnish the
corresponding ether derivative. Typical oxidants for such
transformations include, for instance, Cu(II) salts, benzoqui-
nones, N-fluorinated compounds, λ3-iodanes, and neat oxy-
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

B
K. Rode et al.
Feature
Synthesis
Biographical Sketches
Alexander Breder was born in
ick M. Carreira. Upon comple-
tion of his Ph.D. in 2009, he
joined the group of Prof. Barry
M. Trost at Stanford University
as a postdoctoral fellow. Since
December 2011, he pursues an
independent research career at
the Institute for Organic and
Biomolecular Chemistry at the
Georg-August-University Göt-
tingen, Germany. His research
program is focused on the in-
vestigation of novel concepts on
dual photoredox/selenium ca-
talysis in the context of method
development and the synthesis
of biologically relevant mole-
cules.
1978 in Halle, Germany. In
2005, he received his diploma
degree from the University of
Bielefeld. He then moved to the
Swiss Federal Institute of Tech-
nology Zurich (ETH), Switzer-
land, where he was
a Ph.D.
student in the group of Prof. Er-
Katharina
Rode studied
ter’s degree with a thesis on the
synthesis of chiral thioamides
for oxidative alkene functional-
izations. Her Ph.D. studies, in
the group of Dr. Alexander
Breder, are directed toward the
development of new selenium-
π-acid-catalyzed reactions.
chemistry at the Georg-August-
University Göttingen, Germany.
In 2014, she finished her mas-
Martina Palomba studied
chemistry at the University of
Perugia, Italy. In 2014, she com-
pleted her master’s degree with
a thesis on the addition and
elimination reactions of vinyl
selenones with Prof. Luana Bag-
noli and Prof. Francesca Marini,
and has continued with her
Ph.D. studies in the same
group. During a research stay at
the University of Göttingen,
Germany in the group of Dr.
Breder in 2017, she became in-
terested in selenium-π-acid-cat-
alyzed functionalizations of
olefins.
Stefan Ortgies studied chem-
istry at the Georg-August-Uni-
versity Göttingen, Germany. In
2013, he finished his master’s
degree with a thesis on the syn-
thesis of chiral diselenides for
asymmetric oxidative alkene
functionalizations. During his
Ph.D. in the group of Dr. Alexan-
der Breder, he has worked on
the development of new seleni-
um-catalyzed reactions with a
focus on aerobic photoredox re-
actions.
Rene Rieger studied chemis-
try at the Georg-August-Univer-
sity Göttingen, Germany. In
2016, he obtained his master’s
degree in chemistry with a the-
sis on the oxidative lactoniza-
tion of alkenoic acids using dual
selenium catalysis. He is cur-
rently working on his disserta-
tion in the group of Dr.
Alexander Breder. His work fo-
cuses on selenium-catalyzed ox-
idative functionalizations of
olefins.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

C
K. Rode et al.
Feature
Synthesis
ambient air or neat O2 as the sole oxidant and an organic
photoredox co-catalyst (Scheme 1).17,18 Since in these pre-
ceding investigations the aerobic conversion of simple
alkenes with carboxylic acids and hydrogen phosphates
was found to be facile,18 we surmised that a similar catalytic
regime would potentially also be applicable to the cognate
conversion of alkenes with alcohols.
Table 1 Optimization of the Reaction Conditions
standard conditions:
(2-anisyl-Se)2 (5 mol%)
TAPT (5 mol%)
O
Me
OH
3
Na2HPO4 (0.8 equiv), air
MeCN (0.2 M), hν, 5 h, rt
3
2
Me
6a
7a
Entry
Deviation from standard conditions
Yield (%)a
previous work:
1
2
none
69
31
9
O
O
DMTA instead of TAPT
[Ru(bpz)3](PF6)2 instead of TAPT
TAPT (3 mol% instead of 5 mol%)
DCE instead of MeCN
R3
(PhSe)2 (5–10 mol%)
TAPT (5 mol%)
R3
O
OH
3
R2
MeCN (0.1–0.2 M), air, rt
16–24 h
R1
R2
4
65
29
9
R1
1
2
5
5
O
O
(PhSe)2 (5–10 mol%)
TAPT (5 mol%)
6
acetone instead of MeCN
THF instead of MeCN
(R3O)2P
R2
O
(R3O)2P
+
7
0
OH
DCE (0.1 M), O2, rt
16–24 h
R1
R1
R2
8
1,4-dioxane instead of MeCN
MeNO2 instead of MeCN
0
3
4
9
42
27
67
0
this work:
R3
R3
10
11
12
13
14
(PhSe)2 (10 mol%) instead of (2-anisyl-Se)2 (5 mol%)
O2 and molecular sieves, 3 mol% TAPT
argon instead of air
(2-anisyl-Se)2 (5–10 mol%)
TAPT (3–5 mol%)
O
OH
n
n
R2
MeCN (0.2 M) or alcohol
R1
R2
(R3-OH, neat), air, rt
6 h to 12 d
R1
6
7
no irradiation
0
Scheme 1 Aerobic functionalizations of alkenes facilitated by dual
photoredox/selenium-π-acid catalysis. TAPT = 2,4,6-tris(4-anisyl)pyryli-
no TAPT
0
um tetrafluoroborate
a Yields were determined by 1H NMR spectroscopy using 1,3,5-trimethoxy-
benzene or (Cl2HC)2 as internal standards.
As a result of these considerations, we present herein
the first generalized dual-catalytic allylation of alcohols us-
ing simple alkenes as latent allylating reagents and air as
the terminal oxidant mediated by a selenium-π-acid and a
photoredox catalyst.
or absence of light on the reaction outcome (entries 11–14).
Changing from ambient air to neat oxygen using 3 mol% of
the TAPT photocatalyst resulted in a comparable yield of
67%. However, when the reaction was attempted under ar-
gon, no product formation was recorded, which indicates
that oxygen is indeed serving as the sole oxidant in this
process. Furthermore, when the reaction mixture was de-
prived of light irradiation (465 nm) (entry 13) or the photo-
catalyst (entry 14), we did not detect any of the cyclization
product. These results indicate that light indeed serves as
an indispensable energy source solely made available by the
photocatalyst.19
With an operative set of conditions in hand, we began to
determine the scope and limitations of the title protocol
(Scheme 2). In the early phase of this part of the investiga-
tion we noticed that in some reactions NaH2PO4 provided
slightly better yields than Na2HPO4.
In preceding investigations, we screened a number of
selenium catalysts for their ability to quench the fluores-
cence of common photocatalysts.19 From these experiments
we were able to identify combinations of certain pyrylium
and acridinium salts with electron-neutral and electron-
rich diselenides as promising catalyst pairs for the title pro-
cedure. Comparison of the catalytic activities of 2,4,6-
tris(4-anisyl)pyrylium tetrafluoroborate (TAPT), 10-(3,5-di-
methoxyphenyl)-9-mesityl-1,3,6,8-tetramethoxyacridini-
um tetrafluoroborate) (DMTA)20 and [Ru(bpz)3](PF6)2 (each
5 mol%) in the aerobic cycloetherification of (Z)-dec-4-en-
1-ol (6a) revealed that TAPT was the most efficient co-cata-
lyst (Table 1, entries 1–3).
Lowering of the photocatalyst loading by 40% (i.e., from
5 mol% to 3 mol%) resulted in a tolerable yield reduction of
only four percent (Table 1, entry 4). On the other hand,
changing from acetonitrile to different solvents such as 1,2-
dichloroethane, acetone, 1,4-dioxane, THF, and nitrometh-
ane invariably led to significantly inferior results (entries
5–9). Likewise, the use of (PhSe)2 instead of its anisyl ana-
logue resulted in a markedly lower yield (entry 10). We also
investigated the impact of the atmosphere and the presence
Therefore, we decided to use NaH2PO4 as the base for all
subsequent experiments. In general, the intramolecular
aerobic cycloetherification of unsaturated alcohols 6a–t
furnished the corresponding tetrahydrofuran and tetrahy-
dropyran derivatives 7a–t in moderate to good isolated
yields (up to 71%, shown in parentheses). With regard to
the, in part, significant discrepancies between the isolated
and the crude yields, we suspect that in some cases the high
volatility of the ether products causes significant material
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

D
K. Rode et al.
Feature
Synthesis
hydrofurans 7k–m as mixtures of diastereomers in isolated
yields ranging from 42–66%. Most notably, even additional
non-aromatic carbon–carbon multiple bonds within the
substrate structures (e.g., dienol 6s and enynol 6t) re-
mained intact throughout the cyclization event. These re-
sults underscore the high degree of site-selectivity which
can be rationalized on the basis of kinetic differences be-
tween the observed 6-exo-trig cyclization and the non-
competitive macrocyclization reactions.
(2-anisyl-Se)2 (5 mol%)
TAPT (3 mol%)
O
OH
m
n
NaH2PO4 (0.8 equiv), air
MeCN (0.2 M), hν, 7–28 h, rt
n
m
6a–t
7a–t
O
O
O
O
Ph
Ph
3
Me
7a
Ph
7b
7c
7d
65% (32%)
66% (63%)
48% (34%)
39% (39%)
Our investigations continued with the intermolecular
reactions of alcohols with alkenes. In contrast to the aerobic
cycloetherifications, which proceeded within 7–28 hours,
the reaction times for the cognate intermolecular process
were found to be in the range of many days. We attributed
this observation to the moderate nucleophilicity of alcohols
compared to other nucleophiles such as carboxylates and
phosphates.18 An additional problem that particularly oc-
curred under prolonged reaction times was the Schenck-
ene reaction,21 which led to significant loss of the olefinic
starting material.
O
OEt
O
O
O
O
O
2
2
2
2
CN
OH
OPiv
7g
7e
7f
7h
65% (57%)
40% (31%)
44% (25%)
47% (28%)
OH Me
Ph
O
Me
O
O
O
3
Me
N
Me
O
7i
45% (37%)
7j
7k
F
67% (68%)
65% (62%); dr = 1:1.19
Me
MeO
In order to perform the target process in a reasonable
time frame and thereby reduce any undesired side reac-
tions, we were forced to use the corresponding alcohols 8a–
e as the solvent, incorporate electron-withdrawing groups
in allylic positions within the olefinic substrates 6u–w, and
increase the loadings of the selenium catalyst and the pho-
tocatalyst to 10 mol% and 5 mol%, respectively (Scheme 3).
Furthermore, we noticed that under these conditions the
presence of a base was no longer necessary for the conver-
sion to take place. Consequently, we were able to synthesize
a series of allylic ethers 7ua–wd in moderate isolated yields
(14–48%), however, with excellent regioselectivity. As was
already observed in the intramolecular etherifications (see
Scheme 2), the catalyst system was tolerant of various func-
tional groups such as ester, halide, nitrile and phosphonate.
We also noticed that unfunctionalized alkanols such as eth-
anol (8b), isopropanol (8c), and n-butanol (not shown in
Scheme 3) most often resulted in low yields (e.g., 7uc). Al-
kanols with electron-withdrawing groups at the α-position
provided somewhat improved yields (e.g., 7vd and 7ve). We
suspect that the latter set of alcohols is more readily depro-
tonated by the anionic reduction products derived from O2
and therefore lead to slightly better results. This rationale is
corroborated by the observation that more acidic alcohols
typically reacted faster than unsubstituted examples. It
should be pointed out that in certain cases (e.g., 7va, 7vd,
and 7ve), the differences between the isolated and crude
yields were due to difficulties encountered during chro-
matographic purification of the respective products, thus,
the isolated yields are in these cases not reflective of the ac-
tual efficiency of the title procedure.
O
O
O
Me
7l
7m
7n
69% (66%); dr = 1:1.05
56% (42%); dr = 1:1.16
53% (35%)
Me
OH Me
O
O
Me
Me
O
Ph
Me
3
7o
7p
7q
52% (38%)
71% (72%)
54% (44%)
O
O
O
3
7
3
Cl
7r
7s
7t
62% (47%)
55% (37%)
37% (31%)
Scheme 2 Reactions were carried out on a 1.0 mmol scale under an
atmosphere of ambient air (balloon pressure) with LED irradiation at
465 nm. Isolated yields are given in parentheses and crude yields were
determined by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene or
(Cl2HC)2 as an internal standard
losses during the purification process (e.g., compounds 7a,
7n and 7o). Nonetheless, the method turned out to be very
tolerant of various functionalities such as nitrile, ester, hal-
ogen, carbonate, ether, imide, and unprotected hydroxy
groups. Furthermore, we were able to show that the newly
formed double bond within the products could be obtained
in a mono-, di-, or trisubstituted fashion, emphasizing the
structural flexibility of our etherification protocol. In addi-
tion to primary alcohols, the title method also proved effec-
tive for the conversion of secondary alcohols such as sub-
strates 6k–m, providing access to 2,5-disubstituted tetra-
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

E
K. Rode et al.
Feature
Synthesis
Irradiation experiments were performed at λ = 465 nm using com-
mercially available blue LED strips. The light intensity applied was in
the range of 9000 lx. TLC: Merck Silica Gel 60 F254. Visualization of the
developed chromatogram was performed by fluorescence quenching
at 254 nm and staining with p-anisaldehyde or potassium permanga-
nate. Chromatography: Separations were carried out on Merck Silica
60 (0.063–0.200 mm, 70–230 mesh ASTM) using forced flow. NMR
(1H, 13C) spectra were recorded at 300, 400 or 500 MHz (1H), and 76,
101, or 126 [13C, APT (attached proton test)], respectively, on VARIAN
Unity-300, AMX 300 and Inova 500 instruments in CDCl3 solution at
298 K, unless specified otherwise. On the same machines NMR (19F)
and (31P) spectra were recorded respectively at 282 or 376 MHz and
162 MHz. Chemical shifts (δ) are given in ppm. Multiplicity: s = sin-
glet, d = doublet, t = triplet, q = quartet, quin = quintet, sext = sextet,
sept = septet, m = multiplet). High-resolution mass spectrometry
(HRMS): APEX IV 7T FTICR, BRUKER Daltonics.
(2-anisyl-Se)2 (10 mol%)
TAPT (5 mol%)
OR
+
R
OH
air, 8a–e (0.2 M), hν, 1–12 d, rt
6u–w
8a–e
7ua–wd
OMe
Me
OEt
OiPr
Me
Me
CO2Bn
CO2Bn
CO2Bn
7ua
7ub
7uc
28% (14%)
32% (27%)
31% (19%)
OMe
OEt
OiPr
Me
Me
PO(OEt)2 Me
PO(OEt)2
Me
PO(OEt)2
7va
99% (36%)
7vb
7vc
50% (31%)
O (C6F5)
43% (40%)
O
(C6H4)-4-CF3
PO(OEt)2 Me
4-F3C(C6H4)
O
PO(OEt)2
Me
CN
Tetrahydrofurans and Tetrahydropyrans 7a–t; General Procedure
7vd
68% (48%)
7ve
7wd
54% (25%); E/Z = 2:1
To a solution of the respective alcohol 6a–t (1.00 mmol, 1.0 equiv) in
MeCN (0.2 M) were added (2-anisyl)2Se2 (18.6 mg, 0.05 mmol, 0.05
equiv), TAPT (14.6 mg, 0.03 mmol, 0.03 equiv) and NaH2PO4 (96 mg,
0.8 mmol, 0.8 equiv). The mixture was subjected to irradiation at λ =
465 nm and stirred vigorously using a cross-shaped stir bar (750 rpm)
under ambient air. The solvent was removed under reduced pressure
and the residue purified on silica gel to afford the title compound.
81% (38%)
Scheme 3 Reactions were carried out on a 1.0 mmol scale under an
atmosphere of ambient air (balloon pressure) with LED irradiation at
465 nm. Isolated yields are depicted in parentheses and crude yields
were determined by 1H NMR spectroscopy using 1,3,5-trimethoxyben-
zene, benzaldehyde, phthalide or (Cl2HC)2 as an internal standard
(E)-2-(Hex-1-en-1-yl)tetrahydrofuran (7a)
In conclusion, we have developed an efficient and gen-
eralized procedure for the aerobic dual photoredox/seleni-
um-π-acid-catalyzed cycloetherification of unsaturated al-
cohols. This method gives access to various cyclic allylic
ethers typically in reasonable isolated yields. The corre-
sponding intermolecular process is characterized by a rath-
er sluggish reactivity of the alcohol nucleophiles, which en-
tails prolonged reaction times and diminished yields due to
undesired side reactions. Nonetheless, the overall title pro-
cess is characterized by very high functional group toler-
ance and excellent regioselectivity. Furthermore, the pro-
cess is believed to proceed through the transient photore-
dox catalytic formation of oligomeric, Lewis acidic
selenonium species [(PhSe)nm+], which will immediately re-
act with the olefinic π-system to afford a seleniranium in-
termediate.18 Subsequent attack of the seleniranium ion by
the corresponding alcohol nucleophile followed by oxida-
tive elimination of the selenium residue presumably results
in the formation of the ether products. Future endeavors
will be focused on the application of the aerobic etherifica-
tion in the total synthesis of biologically relevant natural
products and the design of asymmetric variants of this re-
action.
Reaction time: 7 h; eluting with n-pentane/Et2O (9:1).
1
Yield: 49 mg, 0.32 mmol (32%); colorless liquid; H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 65%; Rƒ = 0.31 (n-
pentane/Et2O, 9:1).
IR (neat): 2957, 2926, 2857, 1459, 1377, 1153, 1054, 966, 731 cm–1
1H NMR (400 MHz, CDCl3): δ = 5.67 (dtd, J = 15.2, 6.7, 0.9 Hz, 1 H),
5.44 (ddt, J = 15.3, 7.2, 1.4 Hz, 1 H), 4.22 (q, J = 7.1 Hz, 1 H), 3.89 (ddd,
J = 8.3, 7.3, 6.3 Hz, 1 H), 3.75 (td, J = 7.9, 6.1 Hz, 1 H), 2.08–1.98 (m, 3
H), 1.97–1.79 (m, 2 H), 1.65–1.51 (m, 2 H), 1.33 (tddd, J = 10.0, 8.7, 7.0,
4.3 Hz, 3 H), 0.88 (t, J = 7.1 Hz, 3 H).
13C NMR (101 MHz, CDCl3): δ = 133.0, 130.7, 80.2, 68.0, 32.4, 32.0,
31.4, 26.1, 22.4, 14.1.
.
HRMS (ESI): m/z [M + H]+ calcd for C10H19O: 155.1430; found:
155.1433.
(E)-2-(3-Phenylprop-1-en-1-yl)tetrahydrofuran (7b)
Reaction time: 8 h; eluting with n-pentane/EtOAc (6:4).
Yield: 119 mg, 0.63 mmol (63%); yellow liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 66%; Rƒ = 0.53 (n-
pentane/EtOAc, 60:40).
IR (neat): 3026, 2971, 2870, 1672, 1602, 1495, 1452, 1369, 1178,
1048, 968, 919, 745, 697, 587, 485 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.43–7.22 (m, 2 H), 7.22–7.04 (m, 3 H),
5.89–5.76 (m, 1 H), 5.53 (ddt, J = 15.2, 7.0, 1.6 Hz, 1 H), 4.27 (q, J = 7.0
Hz, 1 H), 3.94–3.84 (m, 1 H), 3.76 (td, J = 7.9, 6.2 Hz, 1 H), 3.37 (d, J =
6.7 Hz, 2 H), 2.19–1.77 (m, 3 H), 1.68–1.52 (m, 1 H).
Unless stated otherwise, all catalytic reactions were carried out under
an atmosphere of air. Chemicals were obtained from commercial
sources and were used without further purification. Yields corre-
spond to those of isolated compounds unless indicated otherwise. Pu-
rity is estimated to be ≥95% based on 1H NMR spectroscopic analysis.
13C NMR (126 MHz, CDCl3): δ = 140.2, 132.4, 130.9, 128.7, 128.5,
126.1, 79.8, 68.1, 38.8, 32.4, 26.1.
HRMS (ESI): m/z [M + Na]+ calcd for C13H16NaO: 211.1093; found:
211.1089.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

F
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Feature
Synthesis
4,4-Diphenyl-2-vinyltetrahydrofuran (7c)
1H NMR (300 MHz, CDCl3): δ = 5.67 (dt, J = 15.4, 6.4 Hz, 1 H), 5.61–
5.51 (m, 1 H), 4.29–4.20 (m, 1 H), 3.94–3.84 (m, 1 H), 3.80–3.71 (m, 1
H), 3.65 (t, J = 6.3 Hz, 2 H), 2.40–2.19 (m, 2 H), 2.16–1.79 (m, 4 H),
1.66–1.52 (m, 1 H).
13C NMR (126 MHz, CDCl3): δ = 133.9, 128.4, 79.8, 68.1, 61.9, 35.8,
32.4, 26.1.
Reaction time: 9 h; eluting with n-pentane/CH2Cl2 (5:95 to 15:85).
1
Yield: 86 mg, 0.34 mmol (34%); colorless liquid; H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 48%; Rƒ = 0.45 (n-
pentane/EtOAc, 60:40).
IR (neat): 3083, 3059, 3026, 2980, 2938, 2925, 2864, 1598, 1493,
1446, 1335, 1056, 988, 925, 873, 843, 773, 756, 732, 696, 670, 582
HRMS (ESI): m/z [M + H]+ calcd for C8H15O2: 143.1067; found:
143.1064.
cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.39–7.27 (m, 6 H), 7.25–7.17 (m, 4 H),
5.91 (ddd, J = 17.1, 10.2, 6.9 Hz, 1 H), 5.25 (ddd, J = 17.1, 1.6, 1.1 Hz, 1
H), 5.11 (ddd, J = 10.2, 1.7, 1.0 Hz, 1 H), 4.68 (dd, J = 8.7, 1.2 Hz, 1 H),
4.51–4.39 (m, 1 H), 4.17 (d, J = 8.7 Hz, 1 H), 2.67 (ddd, J = 12.1, 6.0, 1.2
Hz, 1 H), 2.46 (dd, J = 12.2, 9.7 Hz, 1 H).
(E)-4-(Tetrahydrofuran-2-yl)but-3-en-1-yl Pivalate (7g)
Alcohol 6g (585 μmol) was used; reaction time: 11 h; eluting with n-
pentane/EtOAc (7:1).
1
Yield: 33 mg, 0.15 mmol (25%); colorless liquid; H NMR yield using
13C NMR (76 MHz, CDCl3): δ = 146.1, 145.7, 138.9, 128.6, 128.5,
1,1,2,2-tetrachloroethane as the internal standard: 44%; Rƒ = 0.29 (n-
pentane/EtOAc, 7:1).
127.30, 127.26, 126.6, 126.5, 116.0, 79.8, 79.8, 56.3, 45.3.
HRMS (EI): m/z [M]+ calcd for C18H18O: 250.1358; found: 250.1356.
IR (neat): 2970, 2872, 1726, 1480, 1460, 1398, 1366, 1283, 1150,
1052, 967, 869, 770 cm–1
.
2-(Cyclohexylidenemethyl)tetrahydrofuran (7d)
1H NMR (300 MHz, CDCl3): δ = 5.69–5.59 (m, 1 H), 5.58–5.49 (m, 1 H),
4.29–4.18 (m, 1 H), 4.09 (t, J = 6.7 Hz, 2 H), 3.88 (ddd, J = 8.0, 7.1, 6.3
Hz, 1 H), 3.81–3.71 (m, 1 H), 2.59–2.16 (m, 2 H), 2.08–1.96 (m, 1 H),
1.96–1.80 (m, 2 H), 1.66–1.50 (m, 1 H), 1.18 (s, 9 H).
13C NMR (126 MHz, CDCl3): δ = 178.4, 133.7, 127.3, 79.6, 68.1, 63.5,
38.9, 32.4, 31.9, 27.4, 26.1.
Reaction time: 8 h; eluting with n-pentane/CH2Cl2 (5:95 to 10:90).
Yield: 65 mg, 0.39 mmol (39%); yellow liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 39%; Rƒ = 0.32 (n-
pentane/EtOAc, 60:40).
IR (neat): 2924, 2852, 1670, 1599, 1446, 1337, 1234, 1171, 1049, 983,
HRMS (ESI): m/z [M + H]+ calcd for C13H23O3: 227.1642; found:
227.1643.
935, 855, 751, 637, 470, 381 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 5.11 (dt, J = 8.5, 1.3 Hz, 1 H), 4.51 (td,
J = 8.3, 6.0 Hz, 1 H), 3.86 (dt, J = 8.1, 6.9 Hz, 1 H), 3.77–3.65 (m, 1 H),
2.32–1.77 (m, 7 H), 1.73–1.32 (m, 7 H).
(E)-Ethyl [4-(Tetrahydrofuran-2-yl)but-3-en-1-yl] Carbonate (7h)
Alcohol 6h (524 μmol) was used; reaction time: 7 h; eluting with n-
pentane/EtOAc (7:1).
13C NMR (126 MHz, CDCl3): δ = 143.1, 122.5, 74.8, 67.6, 37.0, 32.8,
29.2, 28.3, 27.8, 26.7, 26.2.
HRMS (ESI): m/z [M + Na]+ calcd for C11H18NaO: 189.1250; found:
189.1253.
1
Yield: 31 mg, 0.14 mmol (28%); colorless liquid; H NMR yield using
1,1,2,2-tetrachloroethane as the internal standard: 47%; Rƒ = 0.23 (n-
pentane/EtOAc, 7:1).
IR (neat): 2978, 2868, 1741, 1464, 1384, 1366, 1247, 1091, 1051,
(E)-5-(Tetrahydrofuran-2-yl)pent-4-enenitrile (7e)
1007, 968, 873, 791 cm–1
.
Reaction time: 9 h; eluting with n-pentane/EtOAc (95:5 to 80:20).
1H NMR (300 MHz, CDCl3): δ = 5.70–5.60 (m, 1 H), 5.61–5.51 (m, 1 H),
4.29–4.20 (m, 1 H), 4.20–4.11 (m, 4 H), 3.93–3.84 (m, 1 H), 3.82–3.70
(m, 1 H), 2.51–2.30 (m, 2 H), 2.14–1.76 (m, 3 H), 1.69–1.49 (m, 1 H),
1.30 (t, J = 7.1 Hz, 3 H).
13C NMR (126 MHz, CDCl3): δ = 155.1, 134.1, 126.6, 79.6, 68.1, 67.1,
64.0, 32.3, 31.8, 26.1, 14.5.
1
Yield: 86 mg, 0.57 mmol (57%); colorless liquid; H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 65%; Rƒ = 0.67 (n-
pentane/EtOAc, 60:40).
IR (neat): 2973, 2867, 2244, 1444, 1372, 1179, 1049, 967, 921, 868
cm–1
.
1H NMR (500 MHz, CDCl3): δ = 5.75–5.54 (m, 2 H), 4.26 (q, J = 6.7 Hz, 1
H), 3.88 (ddd, J = 8.2, 7.3, 6.3 Hz, 1 H), 3.76 (td, J = 7.9, 6.2 Hz, 1 H),
2.49–2.31 (m, 4 H), 2.03 (dddd, J = 12.0, 8.1, 6.7, 5.1 Hz, 1 H), 1.99–
1.80 (m, 2 H), 1.59 (ddt, J = 12.1, 8.4, 7.4 Hz, 1 H).
13C NMR (126 MHz, CDCl3): δ = 134.3, 127.2, 119.2, 79.1, 68.2, 32.2,
28.1, 25.9, 17.3.
HRMS (ESI): m/z [M + H]+ calcd for C11H19O4: 215.1278; found:
215.1281.
(E)-2-[3-(Tetrahydrofuran-2-yl)allyl]isoindoline-1,3-dione (7i)
Reaction time: 7.5 h; eluting with n-pentane/EtOAc (4:1).
Yield: 85 mg, 0.33 mmol (37%); yellow liquid; 1H NMR yield using
1,1,2,2-tetrachloroethane as the internal standard: 45%; Rƒ = 0.19 (n-
pentane/EtOAc, 4:1).
HRMS (ESI): m/z [M + H]+ calcd for C9H14NO: 152.1070; found:
152.1068.
IR (neat): 2972, 2868, 1770, 1705, 1613, 1467, 1428, 1391, 1188,
(E)-4-(Tetrahydrofuran-2-yl)but-3-en-1-ol (7f)
1112, 1087, 1050, 939, 854, 794, 718, 614, 529, 444 cm–1
.
Reaction time: 28.5 h; eluting with n-pentane/EtOAc (2:1 to 1:1).
1H NMR (300 MHz, CDCl3): δ = 7.87–7.81 (m, 2 H), 7.76–7.66 (m, 2 H),
5.84–5.62 (m, 2 H), 4.39–4.13 (m, 3 H), 3.87 (ddd, J = 8.3, 7.1, 6.4 Hz, 1
H), 3.80–3.69 (m, 1 H), 2.08–1.96 (m, 1 H), 1.95–1.78 (m, 2 H), 1.63–
1.51 (m, 1 H).
1
Yield: 44 mg, 0.31 mmol (31%); colorless liquid; H NMR yield using
1,1,2,2-tetrachloroethane as the internal standard: 40%; Rƒ = 0.29 (n-
pentane/EtOAc, 2:1).
IR (neat): 3387, 2944, 2871, 1444, 1373, 1039, 967, 921, 864, 596 cm–1
.
13C NMR (126 MHz, CDCl3): δ = 167.9, 135.1, 134.0, 132.2, 124.2,
123.3, 78.7, 68.2, 39.2, 32.2, 25.9.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

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Feature
Synthesis
HRMS (ESI): m/z [M + H]+ calcd for C15H16NO3: 258.1125; found:
258.1124.
13C NMR (126 MHz, CDCl3): δ = 162.03 (d, J = 244.3 Hz), 161.99 (d, J =
244.1 Hz), 139.4 (d, J = 3.0 Hz), 139.1 (d, J = 2.9 Hz), 132.2, 131.9,
128.1, 127.7, 127.5 (d, J = 8.1 Hz), 127.3 (d, J = 7.9 Hz), 115.10 (d, J =
21.3 Hz), 115.07 (d, J = 21.3 Hz), 80.9, 80.7, 80.3, 80.0, 35.7, 34.7, 33.3,
32.2, 18.0, 17.9.
19F NMR (282 MHz, CDCl3): δ = −115.9 (tt, J = 8.9, 5.5 Hz), −116.0 (tt,
J = 8.7, 5.5 Hz).
(E)-2,6-Dimethyl-8-(tetrahydrofuran-2-yl)oct-7-en-2-ol (7j)
Reaction time: 7 h; eluting with n-pentane/EtOAc (2:3).
Yield: 154 mg, 680 μmol (68%); yellow liquid; 1:1 mixture of diaste-
reomers (see the 13C NMR spectrum); 1H NMR yield using 1,3,5-tri-
methoxybenzene as the internal standard: 67%; Rƒ = 0.21 (n-pen-
tane/EtOAc, 2:3).
HRMS (ESI): m/z [M + H]+ calcd for C13H16OF: 207.1180; found:
207.1182.
IR (neat): 3442, 2965, 2868, 1460, 1375, 1160, 1053, 968, 938, 910,
865, 764, 551 cm–1
.
(E)-2-(4-Methoxyphenyl)-5-(prop-1-en-1-yl)tetrahydrofuran (7m)
Reaction time: 16 h; eluting with n-pentane/EtOAc (20:1).
1H NMR (300 MHz, CDCl3): δ = 5.69–5.46 (m, 1 H), 5.40 (ddd, J = 15.3,
6.8, 0.7 Hz, 1 H), 4.22 (q, J = 6.9 Hz, 1 H), 3.97–3.83 (m, 1 H), 3.80–3.69
(m, 1 H), 2.25–1.74 (m, 4 H), 1.66–1.52 (m, 1 H), 1.47–1.23 (m, 7 H),
1.19 (s, 6 H), 0.98 (dd, J = 6.7, 3.4 Hz, 3 H).
Yield: 91 mg, 0.42 mmol (42%); colorless liquid; inseparable mixture
1
of diastereomers (dr = 1.1.16); H NMR yield using 1,1,2,2-tetrachlo-
roethane as the internal standard: 56%; Rƒ = 0.25 (n-pentane/EtOAc,
20:1).
13C NMR (126 MHz, CDCl3): δ = 138.3, 138.2, 129.14, 129.06, 80.14,
80.10, 71.14, 71.11, 68.00, 67.99, 44.2, 44.1, 37.5, 37.4, 36.5, 32.6,
32.5, 29.5, 29.4, 26.14, 26.10, 22.2, 22.1, 20.58, 20.56.
IR (neat): 2937, 1612, 1512, 1462, 1301, 1242, 1172, 1032, 963, 931,
828, 540 cm–1
.
HRMS (ESI): m/z [M + Na]+ calcd for C14H26NaO2: 249.1825; found:
249.1827.
1H NMR (300 MHz, CDCl3): δ = 7.51–7.22 (m, 2.32 H), 6.98–6.66 (m,
2.16 H), 5.85–5.48 (m, 2 H), 4.99 (dq, J = 8.1, 6.4 Hz, 0.53 H), 4.91–4.79
(m, 0.66 H), 4.63–4.52 (m, 0.40 H), 4.45–4.34 (m, 0.47 H), 3.80 (s, 3.49
H), 2.45–1.97 (m, 2.25 H), 1.96–1.75 (m, 1.67 H), 1.75–1.66 (m, 3.67
H).
13C NMR (126 MHz, CDCl3): δ = 158.84, 158.80, 135.7, 135.4, 132.4,
132.2, 127.8, 127.5, 127.2, 127.0, 113.8, 113.7, 80.8, 80.7, 80.5, 80.3,
55.4, 35.5, 34.6, 33.4, 32.4, 18.0, 17.9.
(E)-2-Phenyl-5-(prop-1-en-1-yl)tetrahydrofuran (7k)
Reaction time: 16 h; eluting with n-pentane/EtOAc (20:1).
Yield: 117 mg, 621 μmol (62%); colorless liquid; inseparable mixture
of diastereomers (dr = 1:1.19); 1H NMR yield using 1,1,2,2-tetrachlo-
roethane as the internal standard: 65%; Rƒ = 0.41 (n-pentane/EtOAc,
20:1).
HRMS (ESI): m/z [M + H]+ calcd for C14H19O2: 219.1380; found:
219.1382.
IR (neat): 2966, 2867, 1493, 1449, 1355, 1043, 1027, 962, 931, 877,
751, 697 cm–1
.
2-(Cyclohexylidenemethyl)tetrahydro-2H-pyran (7n)
Reaction time: 17 h; eluting with n-pentane/CH2Cl2 (1:9).
1H NMR (300 MHz, CDCl3): δ = 7.42–7.28 (m, 4.27 H), 7.28–7.18 (m,
1.12 H), 5.88–5.49 (m, 2 H), 5.14–5.00 (m, 0.60 H), 4.93 (td, J = 7.1, 3.5
Hz, 0.49 H), 4.61 (ddddd, J = 7.2, 6.6, 5.5, 1.4, 0.7 Hz, 0.46 H), 4.43 (dtd,
J = 7.3, 6.7, 0.6 Hz, 0.39 H), 2.53–2.27 (m, 1.18 H), 2.24–2.04 (m, 1.37
H), 2.01–1.76 (m, 1.86 H), 1.78–1.69 (m, 3.72 H).
1
Yield: 62 mg, 0.35 mmol (35%); colorless liquid; H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 53%; Rƒ = 0.43 (n-
pentane/CH2Cl2, 1:9).
13C NMR (126 MHz, CDCl3): δ = 143.8, 143.4, 132.3, 132.1, 128.30,
128.26, 128.3, 127.9, 127.6, 127.15, 127.08, 125.9, 125.6, 80.9, 80.7,
80.6, 80.5, 35.6, 34.7, 33.3, 32.3, 18.0, 17.9.
HRMS (ESI): m/z [M + H]+ calcd for C13H17O: 189.1274; found:
189.1278.
IR (neat): 2926, 2851, 1446, 1204, 1174, 1084, 1051, 1033, 992, 901,
846 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 5.11 (dquin, J = 8.0, 1.2 Hz, 1 H), 4.29–
3.87 (m, 2 H), 3.47 (td, J = 11.4, 2.5 Hz, 1 H), 2.35–1.94 (m, 5 H), 1.88–
1.75 (m, 1 H), 1.69–1.26 (m, 10 H).
13C NMR (126 MHz, CDCl3): δ = 142.7, 123.3, 74.3, 68.4, 37.1, 32.9,
29.7, 28.6, 28.1, 26.9, 26.1, 23.8.
HRMS (ESI): m/z [M + H]+ calcd for C12H21O: 181.1587; found:
(E)-2-(4-Fluorophenyl)-5-(prop-1-en-1-yl)tetrahydrofuran (7l)
Reaction time: 16 h; eluting with n-pentane/EtOAc (20:1).
181.1588.
Yield: 137 mg, 664 μmol (66%); colorless liquid, inseparable mixture
of diastereomers (dr = 1:1.05); 1H NMR yield using 1,1,2,2-tetrachlo-
roethane as the internal standard: 69%; Rƒ = 0.44 (n-pentane/EtOAc,
20:1).
(E)-2-(3-Methylbut-1-en-1-yl)tetrahydro-2H-pyran (7o)
Reaction time: 7 h; eluting with n-pentane/Et2O (9:1).
IR (neat): 2967, 2864, 1605, 1509, 1449, 1352, 1294, 1221, 1155,
1
Yield: 58 mg, 0.38 mmol (38%); colorless liquid; H NMR yield using
1045, 963, 931, 831, 782 cm–1
.
1,3,5-trimethoxybenzene as the internal standard: 52%; Rƒ = 0.43 (n-
1H NMR (300 MHz, CDCl3): δ = 7.42–7.27 (m, 1.78 H), 7.11–6.80 (m,
1.84 H), 5.89–5.46 (m, 2 H), 5.07–4.94 (m, 0.62 H), 4.88 (t, J = 6.9 Hz,
0.63 H), 4.66–4.53 (m, 0.53 H), 4.41 (tdt, J = 7.2, 6.5, 0.6 Hz, 0.50 H),
2.64–2.26 (m, 1.10 H), 2.25–2.05 (m, 1.24 H), 1.99–1.77 (m, 1.66 H),
1.77–1.64 (m, 3.10 H).
pentane/Et2O, 9:1).
IR (neat): 2955, 2934, 2841, 1464, 1362, 1263, 1204, 1176, 1085,
1051, 1035, 968, 896, 847 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 5.64 (ddd, J = 15.6, 6.4, 1.1 Hz, 1 H),
5.41 (ddd, J = 15.6, 6.2, 1.4 Hz, 1 H), 4.06–3.95 (m, 1 H), 3.73 (dddd, J =
10.8, 6.2, 2.1, 1.1 Hz, 1 H), 3.55–3.42 (m, 1 H), 2.39–2.20 (m, 1 H),
1.92–1.77 (m, 1 H), 1.70–1.29 (m, 5 H), 0.98 (dd, J = 6.7, 0.9 Hz, 6 H).
13C NMR (126 MHz, CDCl3): δ = 138.8, 128.4, 78.5, 68.5, 32.5, 30.9,
26.1, 23.7, 22.5.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

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Synthesis
1
HRMS (ESI): m/z [M + H]+ calcd for C10H19O: 155.1430; found:
155.1436.
Yield: 86 mg, 0.37 mmol (37%); colorless liquid; H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 55%; Rƒ = 0.23 (n-
pentane/Et2O, 20:1).
(E)-2,6-Dimethyl-8-(tetrahydro-2H-pyran-2-yl)oct-7-en-2-ol (7p)
Reaction time: 7 h; eluting with n-pentane/Et2O (1:1).
IR (neat): 2924, 2852, 1727, 1640, 1463, 1439, 1371, 1263, 1203,
1175, 1085, 1035, 966, 907, 861, 843, 810, 723 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 5.80 (ddt, J = 16.9, 10.2, 6.7 Hz, 1 H),
5.66 (dtd, J = 15.5, 6.6, 1.1 Hz, 1 H), 5.45 (ddt, J = 15.5, 6.2, 1.4 Hz, 1 H),
5.04–4.88 (m, 2 H), 4.00 (ddt, J = 11.6, 4.1, 1.8 Hz, 1 H), 3.73 (ddd, J =
9.2, 4.5, 1.9 Hz, 1 H), 3.56–3.40 (m, 1 H), 2.02 (qdd, J = 6.9, 5.4, 1.2 Hz,
4 H), 1.90–1.76 (m, 1 H), 1.70–1.19 (m, 15 H).
Yield: 172 mg, 717 μmol (71%); yellow liquid; mixture of diastereo-
mers (see the 13C NMR spectrum); 1H NMR yield using 1,3,5-trime-
thoxybenzene as the internal standard: 72%; Rƒ = 0.19 (n-pen-
tane/Et2O, 1:1).
IR (neat): 3437, 2934, 2845, 1463, 1374, 1203, 1175, 1083, 1049,
13C NMR (126 MHz, CDCl3): δ = 139.3, 131.9, 131.3, 114.2, 78.4, 68.5,
1033, 968, 938, 895, 754 cm–1
.
34.0, 32.5, 32.4, 29.5, 29.4, 29.31, 29.28, 29.1, 26.1, 23.7.
HRMS (ESI): m/z [M + Na]+ calcd for C16H28ONa: 259.2032; found:
259.2034.
1H NMR (400 MHz, CDCl3): δ = 5.53 (dddd, J = 15.7, 8.4, 7.4, 1.0 Hz, 1
H), 5.42 (dddd, J = 15.6, 6.2, 2.3, 0.9 Hz, 1 H), 4.00 (ddt, J = 11.6, 4.0, 1.6
Hz, 1 H), 3.80–3.68 (m, 1 H), 3.53–3.41 (m, 1 H), 2.16–2.04 (m, 1 H),
1.90–1.77 (m, 1 H), 1.72–1.22 (m, 12 H), 1.19 (s, 6 H), 0.98 (dd, J = 6.7,
3.4 Hz, 3 H).
13C NMR (101 MHz, CDCl3): δ = 137.4, 137.3, 129.9, 129.7, 78.5, 78.3,
71.2, 71.1, 68.5, 44.10, 44.08, 37.4, 37.3, 36.52, 36.46, 32.6, 32.5,
29.41, 29.38, 29.36, 26.03, 26.01, 23.6, 22.1, 22.0, 20.6, 20.4.
(E)-2-(Hept-1-en-6-yn-1-yl)tetrahydro-2H-pyran (7t)
Reaction time: 14.5 h; eluting with n-pentane/Et2O (30:1).
1
Yield: 54 mg, 0.31 mmol (31%); colorless liquid; H NMR yield using
1,1,2,2-tetrachloroethane as the internal standard: 37%; Rƒ = 0.11 (n-
pentane/Et2O, 30:1).
HRMS (ESI): m/z [M + H]+ calcd for C15H29O2: 241.2162; found:
241.2160.
IR (neat): 3304, 2933, 2843, 1439, 1344, 1263, 1203, 1175, 1083,
1049, 1034, 967, 896, 842, 810 cm–1
.
(E)-2-(3-Phenylprop-1-en-1-yl)tetrahydro-2H-pyran (7q)
Reaction time: 7 h; eluting with n-pentane/CH2Cl2 (1:9).
Yield: 90 mg, 0.44 mmol (44%); yellow liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 54%; Rƒ = 0.43 (n-
pentane/CH2Cl2, 1:9).
1H NMR (300 MHz, CDCl3): δ = 5.64 (dtd, J = 15.5, 6.5, 0.9 Hz, 1 H),
5.50 (ddt, J = 15.5, 6.0, 1.2 Hz, 1 H), 4.06–3.95 (m, 1 H), 3.81–3.68 (m,
1 H), 3.53–3.40 (m, 1 H), 2.37–2.04 (m, 4 H), 1.93 (t, J = 2.6 Hz, 1 H),
1.89–1.79 (m, 1 H), 1.68–1.23 (m, 7 H).
13C NMR (126 MHz, CDCl3): δ = 132.3, 130.3, 84.4, 78.2, 68.52, 68.49,
32.4, 31.4, 28.1, 26.1, 23.6, 18.1.
HRMS (ESI): m/z [M + Na]+ calcd for C12H19O: 179.1430; found:
IR (neat): 2933, 2841, 1495, 1453, 1438, 1204, 1175, 1083, 1048,
1033, 967, 894, 745, 697, 580, 543, 497, 456 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.38–7.24 (m, 2 H), 7.24–7.03 (m, 3 H),
5.83 (dtd, J = 15.4, 6.7, 1.2 Hz, 1 H), 5.54 (ddt, J = 15.4, 6.1, 1.5 Hz, 1 H),
4.09–3.95 (m, 1 H), 3.84–3.73 (m, 1 H), 3.59–3.42 (m, 1 H), 3.41–3.24
(m, 2 H), 1.94–1.78 (m, 1 H), 1.74–1.30 (m, 5 H).
13C NMR (126 MHz, CDCl3): δ = 140.2, 132.8, 130.2, 128.7, 128.4,
126.1, 78.1, 68.5, 39.0, 32.4, 26.1, 23.6.
179.1429.
Intermolecular Etherification; General Procedure
To a solution of the respective alkene 6u–w (1.00 mmol, 1.0 equiv) in
the respective alcohol 8a–e (0.2 M) were added (2-anisyl)2Se2 (0.10
mmol, 0.10 equiv) and TAPT (24.0 mg, 0.05 mmol, 0.05 equiv). The
mixture was subjected to irradiation at λ = 465 nm and stirred vigor-
ously using a cross-shaped stir bar (750 rpm) under ambient air. The
solvent was removed under reduced pressure and the residue puri-
fied on silica gel to afford the title compound.
HRMS (ESI): m/z [M + H]+ calcd for C14H19O: 203.1430; found:
203.1434.
(E)-2-(5-Chloropent-1-en-1-yl)tetrahydro-2H-pyran (7r)
Alcohol 6r (818 μmol) was used; reaction time: 7 h; eluting with n-
pentane/CH2Cl2 (1:9).
Benzyl (E)-4-Methoxyhex-2-enoate (7ua)
Alkene 6u (500 μmol), MeOH (2.5 mL), (2-anisyl)2Se2 (18 mg, 50 μmol,
0.1 equiv) and TAPT (12.0 mg, 0.025 mmol, 0.05 equiv) were em-
ployed; reaction time: 70.5 h; eluting with n-pentane/EtOAc (25:1).
Yield: 32 mg, 136 μmol (27%); colorless liquid; 1H NMR yield using
1,1,2,2-tetrachloroethane as the internal standard: 32%; Rƒ = 0.43 (n-
pentane/EtOAc 10:1).
Yield: 88 mg, 0.47 mmol (47%); yellow liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 62%; Rƒ = 0.44 (n-
pentane/CH2Cl2, 1:9).
IR (neat): 2934, 2844, 1440, 1265, 1204, 1083, 1049, 1034, 968, 895,
726, 653 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 5.64 (dtd, J = 15.5, 6.3, 0.8 Hz, 1 H),
5.52 (ddt, J = 15.5, 5.8, 1.0 Hz, 1 H), 4.08–3.95 (m, 1 H), 3.82–3.68 (m,
1 H), 3.53 (t, J = 6.6 Hz, 2 H), 2.18 (dddd, J = 8.0, 7.0, 6.0, 0.8 Hz, 2 H),
2.03–1.74 (m, 3 H), 1.73–1.23 (m, 6 H).
13C NMR (126 MHz, CDCl3): δ = 132.8, 129.4, 78.1, 68.5, 44.6, 32.4,
32.1, 29.6, 26.1, 23.6.
IR (neat): 2968, 2933, 2878, 2824, 1717, 1657, 1455, 1377, 1355,
1266, 1198, 1159, 1127, 1087, 981, 846, 737, 696 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.47–7.30 (m, 5 H), 6.85 (dd, J = 15.8,
6.4 Hz, 1 H), 6.04 (dd, J = 15.8, 1.3 Hz, 1 H), 5.20 (s, 2 H), 3.67 (qd, J =
6.3, 1.3 Hz, 1 H), 3.31 (s, 3 H), 1.89–1.36 (m, 2 H), 0.92 (t, J = 7.4 Hz, 3
H).
13C NMR (126 MHz, CDCl3): δ = 166.2, 148.9, 136.0, 128.7, 128.4,
128.4, 121.9, 81.9, 66.4, 57.2, 27.7, 9.6.
HRMS (ESI): m/z [M + Na]+ calcd for C10H17ClONa: 211.0860; found:
211.0865.
HRMS (ESI): m/z [M + Na]+ calcd for C14H18O3Na: 257.1148; found:
257.1146.
(E)-2-(Undeca-1,10-dien-1-yl)tetrahydro-2H-pyran (7s)
Reaction time: 17 h; eluting with n-pentane/Et2O (20:1).
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

I
K. Rode et al.
Feature
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Benzyl (E)-4-Ethoxyhex-2-enoate (7ub)
Yield: 73 mg, 0.31 mmol (31%); yellow liquid; 1H NMR yield using
phthalide as the internal standard: 50%; Rƒ = 0.10 (CH2Cl2/acetone,
30:1 + 1% AcOH).
(o-MeOPh)2Se2 (36 mg, 100 μmol, 0.1 equiv) was employed; reaction
time: 92 h; eluting with n-pentane/EtOAc (50:1).
1
IR (neat): 2978, 2934, 2904, 2872, 1721, 1634, 1444, 1392, 1369,
Yield: 48 mg, 0.19 mmol (19%); colorless liquid; H NMR yield using
1336, 1245, 1206, 1163, 1094, 1050, 1020, 957, 855, 828, 749 cm–1
.
1,1,2,2-tetrachloroethane as the internal standard: 31%; Rƒ = 0.31 (n-
1H NMR (400 MHz, CDCl3): δ = 6.68 (ddd, J = 22.4, 17.2, 5.2 Hz, 1 H),
5.85 (ddd, J = 20.8, 17.2, 1.4 Hz, 1 H), 4.16–4.02 (m, 4 H), 3.98 (dddd,
J = 6.6, 5.2, 2.5, 1.4 Hz, 1 H), 3.46 (dqd, J = 9.2, 7.0, 2.1 Hz, 2 H), 1.32 (tt,
J = 7.1, 0.3 Hz, 6 H), 1.26 (d, J = 6.6 Hz, 3 H), 1.20 (t, J = 7.0 Hz, 3 H).
13C NMR (101 MHz, CDCl3): δ = 154.2 (d, J = 4.4 Hz), 116.4 (d, J = 188.1
Hz), 75.5 (d, J = 21.9 Hz), 64.6, 61.9 (dd, J = 5.6, 2.5 Hz), 20.7 (d, J = 2.1
Hz), 16.5 (d, J = 6.4 Hz), 15.5.
pentane/EtOAc 50:1).
IR (neat): 2972, 2932, 2875, 1719, 1658, 1456, 1377, 1338, 1268,
1164, 1126, 1092, 983, 748, 697 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.47–7.30 (m, 5 H), 6.87 (dd, J = 15.8,
6.2 Hz, 1 H), 6.03 (dd, J = 15.8, 1.3 Hz, 1 H), 5.19 (d, J = 0.5 Hz, 2 H),
3.77 (qd, J = 6.2, 1.4 Hz, 1 H), 3.53 (dq, J = 9.3, 7.0 Hz, 1 H), 3.38 (dqd,
J = 9.2, 7.0, 0.9 Hz, 1 H), 1.69–1.49 (m, 2 H), 1.20 (t, J = 7.0 Hz, 3 H),
1.08–0.79 (m, 3 H).
31P NMR (162 MHz, CDCl3): δ = 18.5.
13C NMR (126 MHz, CDCl3): δ = 166.2, 149.5, 136.1, 128.6, 128.32,
HRMS (ESI): m/z [M + H]+ calcd for C10H22O4P: 237.1250; found:
128.30, 121.3, 80.1, 66.4, 64.9, 28.1, 15.6, 9.8.
237.1257.
HRMS (ESI): m/z [M + Na]+ calcd for C15H20O3Na: 271.1305; found:
271.1303.
Diethyl (E)-(3-Isopropoxybut-1-en-1-yl)phosphonate (7vc)
Reaction time: 12 d; eluting with CH2Cl2/acetone (30:1 + 1% AcOH).
Benzyl (E)-4-Isopropoxyhex-2-enoate (7uc)
Yield: 101 mg, 402 μmol (40%); yellow liquid; 1H NMR yield using
benzaldehyde as the internal standard: 43%; Rƒ = 0.10 (CH2Cl2/ace-
tone, 30:1 + 1% AcOH).
Reaction time: 63 h; eluting with CH2Cl2.
Yield: 37 mg, 149 μmol (14%); colorless liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 28%; Rƒ = 0.20
(CH2Cl2).
IR (neat): 1975, 1934, 1909, 1872, 1722, 1633, 1445, 1369, 1247,
1121, 1020, 958, 851, 802, 751 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 6.70 (ddd, J = 22.2, 17.2, 4.9 Hz, 1 H),
5.86 (ddd, J = 21.1, 17.2, 1.5 Hz, 1 H), 4.14–4.01 (m, 5 H), 3.60 (quin, J =
6.1 Hz, 1 H), 1.32 (td, J = 7.1, 0.5 Hz, 6 H), 1.23 (d, J = 6.6 Hz, 3 H), 1.14
(dd, J = 6.1, 3.2 Hz, 6 H).
13C NMR (101 MHz, CDCl3): δ = 155.1 (d, J = 4.5 Hz), 115.8 (d, J = 188.3
Hz), 72.8 (d, J = 21.7 Hz), 70.1, 62.0 (dd, J = 5.6, 3.0 Hz), 23.1, 22.1, 21.3
(d, J = 2.1 Hz), 16.5 (d, J = 6.4 Hz).
IR (neat): 2970, 2933, 2876, 2362, 2323, 1717, 1655, 1498, 1457,
1377, 1330, 1268, 1161, 1121, 1062, 1005, 983, 913, 861, 737, 697
cm–1
.
1H NMR (400 MHz, CDCl3): δ = 7.48–7.29 (m, 5 H), 6.90 (dd, J = 15.7,
5.8 Hz, 1 H), 6.04 (dd, J = 15.7, 1.4 Hz, 1 H), 5.28–5.09 (m, 2 H), 3.86
(qd, J = 6.0, 1.4 Hz, 1 H), 3.58 (sept, J = 6.1 Hz, 1 H), 1.68–1.49 (m, 2 H),
1.29–1.04 (m, 6 H), 0.93 (t, J = 7.4 Hz, 3 H).
13C NMR (101 MHz, CDCl3): δ = 166.4, 150.4, 136.1, 128.7, 128.4,
31P NMR (162 MHz, CDCl3): δ = 18.8.
128.3, 120.8, 77.5, 70.1, 66.4, 28.4, 23.3, 21.9, 9.9.
HRMS (ESI): m/z [M + Na]+ calcd for C16H22NaO3: 285.1461; found:
HRMS (ESI): m/z [M + H]+ calcd for C11H24O4P: 251.1407; found:
251.1400.
285.1460.
Diethyl (E)-(3-{[4-(Trifluoromethyl)benzyl]oxy}but-1-en-1-
yl)phosphonate (7vd)
Diethyl (E)-(3-Methoxybut-1-en-1-yl)phosphonate (7va)
Reaction time: 8 d; eluting with CH2Cl2/acetone (20:1 + 1% AcOH).
Alkene 6v (700 μmol), [4-(trifluoromethyl)phenyl]methanol (3.5 mL),
Ph2Se2 (22 mg, 70 μmol, 0.1 equiv) and TAPT (17.0 mg, 0.035 mmol,
0.05 equiv) were employed; reaction time: 73 h; eluting with CH2-
Cl2/acetone (30:1 + 1% AcOH).
Yield: 81 mg, 0.36 mmol (36%); yellow liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: >99%; Rƒ = 0.07
(CH2Cl2/acetone, 20:1 + 1% AcOH).
Yield: 123 mg, 0.34 mmol (48%); brown liquid; 1H NMR yield using
1,3,5-trimethoxybenzene as the internal standard: 68%; Rƒ = 0.21
(CH2Cl2/acetone, 30:1 + 1% AcOH).
IR (neat): 2980, 2933, 2905, 2871, 2826, 1744, 1722, 1635, 1444,
1392, 1369, 1337, 1248, 1216, 1112, 1049, 1020, 956, 858, 826, 789,
746 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 6.66 (ddd, J = 22.4, 17.2, 5.3 Hz, 1 H),
5.85 (ddd, J = 20.5, 17.2, 1.4 Hz, 1 H), 4.08 (dqt, J = 8.4, 7.1, 1.1 Hz, 4 H),
3.87 (qddd, J = 6.6, 5.3, 2.4, 1.4 Hz, 1 H), 3.31 (s, 3 H), 1.32 (t, J = 7.1 Hz,
6 H), 1.26 (d, J = 6.6 Hz, 3 H).
13C NMR (101 MHz, CDCl3): δ = 153.5 (d, J = 4.3 Hz), 116.9 (d, J = 187.8
Hz), 77.4, 61.9 (dd, J = 5.6, 2.1 Hz), 56.9, 20.3 (d, J = 1.9 Hz), 16.5 (d, J =
6.2 Hz).
IR (neat): 2987, 2935, 2871, 1623, 1444, 1424, 1392, 1369, 1325,
1248, 1161, 1121, 1066, 1051, 1017, 956, 823 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 7.70–7.53 (m, 2 H), 7.55–7.40 (m, 2 H),
6.72 (ddd, J = 22.4, 17.2, 5.4 Hz, 1 H), 5.92 (ddd, J = 20.2, 17.2, 1.4 Hz, 1
H), 4.61 (d, J = 12.5 Hz, 1 H), 4.51 (d, J = 12.5 Hz, 1 H), 4.26–3.87 (m, 5
H), 1.37–1.30 (m, 9 H).
13C NMR (101 MHz, CDCl3): δ = 153.0 (d, J = 4.5 Hz), 142.4, 130.0 (d, J =
32.3 Hz), 127.6, 125.6 (q, J = 271.8 Hz), 125.5 (q, J = 3.8 Hz), 117.4 (d,
J = 188.1 Hz), 75.6 (d, J = 22.1 Hz), 70.2, 61.7–62.4 (m), 20.6 (d, J = 1.9
Hz), 16.5 (d, J = 6.2 Hz).
31P NMR (162 MHz, CDCl3): δ = 18.3.
HRMS (ESI): m/z [M + H]+ calcd for C9H20O4P: 223.1094; found:
223.1095.
19F NMR (376 MHz, CDCl3): δ = −62.5.
31P NMR (162 MHz, CDCl3): δ = 17.9.
Diethyl (E)-(3-Ethoxybut-1-en-1-yl)phosphonate (7vb)
Reaction time: 8.5 d; eluting with CH2Cl2/acetone (30:1 + 1% AcOH).
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

J
K. Rode et al.
Feature
Synthesis
HRMS (ESI): m/z [M + H]+ calcd for C16H23F3O4P: 367.1281; found:
367.1283.
Acknowledgment
We thank Prof. Dr. Lutz Ackermann (University of Göttingen) for gen-
erous technical support. We want to thank Prof. Dr. Claudio Santi and
Prof. Dr. Francesca Marini for establishing an Erasmus exchange for
M.P.
Diethyl (E)-{3-[(Perfluorophenyl)methoxy]but-1-en-1-yl}phos-
phonate (7ve)
Reaction time: 8.5 d; eluting with CH2Cl2/acetone (30:1 + 1% AcOH).
Yield: 148 mg, 381 μmol (38%); yellow liquid; 1H NMR yield using
benzaldehyde as the internal standard: 81%; Rƒ = 0.25 (CH2Cl2/ace-
tone, 30:1 + 1% AcOH).
Supporting Information
Supporting information for this article is available online at
https://doi.org/10.1055/s-0037-1609938.
IR (neat): 2983, 2936, 2909, 2875, 1750, 1722, 1656, 1636, 1522,
1504, 1393, 1305, 1248, 1123, 1046, 1022, 957, 936, 848, 821, 787,
S
u
p
p
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S
u
p
p
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f
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753, 673 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 6.67 (ddd, J = 22.4, 17.2, 5.4 Hz, 1 H),
5.90 (ddd, J = 20.0, 17.2, 1.4 Hz, 1 H), 4.60 (dt, J = 11.0, 1.9 Hz, 1 H),
4.52 (dt, J = 11.2, 1.9 Hz, 1 H), 4.26–3.96 (m, 5 H), 1.33 (td, J = 7.1, 1.3
Hz, 6 H), 1.29 (d, J = 6.5 Hz, 3 H).
13C NMR (126 MHz, CDCl3): δ = 152.4 (d, J = 4.8 Hz), 145.7 (dddt, J =
249.3, 11.9, 8.2, 3.9 Hz), 141.6 (dtt, J = 255.0, 13.4, 5.3 Hz), 137.6 (m),
117.6 (d, J = 188.0 Hz), 111.3 (td, J = 18.0, 3.8 Hz), 76.3 (d, J = 22.3 Hz),
62.1 (dd, J = 5.6, 2.1 Hz), 58.0 (d, J = 2.9 Hz), 20.7 (d, J = 2.0 Hz), 16.5 (d,
J = 6.3 Hz).
References
(1) Dewick, P. M. In Medicinal Natural Products: A Biosynthetic
Approach, 3rd Ed.; John Wiley & Sons: Chichester, 2009.
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(3) (a) D’souza, A. A.; Shegokar, R. Expert Opin. Drug Delivery 2016,
13, 1257. (b) Tan, S.; Zou, C.; Zhang, W.; Yin, M.; Gao, X.; Tang, Q.
Drug Delivery 2017, 24, 1831.
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Slaga, T. J.; Snyder, P. W.; Andersen, F. A. Int. J. Toxicol. 2012, 31,
169S. (b) Jang, H.-J.; Shin, C.-Y.; Kim, K.-B. Toxicol. Res. 2015, 31,
105.
19F NMR (376 MHz, CDCl3): δ = –143.0 (m), –153.5 (m), –161.8 (m).
31P NMR (162 MHz, CDCl3): δ = 17.7.
HRMS (ESI): m/z [M + H]+ calcd for C15H19F5O4P: 389.0936; found:
389.0933.
(5) (a) Schneider, S. J. In Engineered Materials Handbook: Ceramics
and Glasses;4Vo.
l
CRC Press: Boca Raton, 1991. (b) McEntire, B. J.; Bal,
(E/Z)-4-{[4-(Trifluoromethyl)benzyl]oxy}pent-2-enenitrile (7wd)
Reaction time: 1 d; eluting with n-pentane/EtOAc (30:1).
Yield: 63 mg, 0.25 mmol (25%) (E/Z = 2:1); yellow liquid; 1H NMR
yield using 1,1,2,2-tetrachloroethane as the internal standard: 54%
(E/Z = 2:1); Rƒ = 0.10 (n-pentane/EtOAc).
B. S.; Rahaman, M. N.; Chevalier, J.; Pezzotti, G. J. Eur. Ceram. Soc.
2015, 35, 4327.
(6) (a) Williamson, W. J. Chem. Soc. 1852, 106, 229. (b) Ullmann, F.
Ber. 1904, 37, 853. (c) Mann, G.; Hartwig, J. F. J. Am. Chem. Soc.
1996, 118, 13109. (d) Kürti, L.; Czakó, B. In Strategic Applications
of Named Reactions in Organic Synthesis: Background and
Detailed Mechanisms; Elsevier Academic Press: Burlington,
2005.
IR (neat): E isomer: 2982, 2936, 2869, 2360, 2341, 2226, 1729, 1621,
1421, 1325, 1163, 1121, 1065, 1018, 965, 824 cm–1; Z isomer: 2984,
2934, 2872, 2360, 2341, 1326, 1163, 1122, 1066, 1019, 824 cm–1
.
(7) For representative reviews, see: (a) Trost, B. M. Chem. Pharm.
Bull. 2002, 50, 1. (b) Trost, B. M. J. Org. Chem. 2004, 69, 5813.
(c) Lu, Z.; Ma, S. Angew. Chem. Int. Ed. 2008, 47, 258. (d) Butt, N.
A.; Zhang, W. Chem. Soc. Rev. 2015, 44, 7929. For representative
Pd-catalyzed methods, see: (e) Kirsch, S. F.; Overman, L. E.;
White, N. S. Org. Lett. 2007, 9, 911. (f) Lam, F. L.; Au-Yeung, T. T.-
L.; Kwong, F. Y.; Zhou, Z.; Wong, K. Y.; Chan, A. S. C. Angew.
Chem. Int. Ed. 2008, 47, 1280. (g) Liu, Z.; Du, H. Org. Lett. 2010,
12, 3054. For exemplary reports on Ru-catalyzed etherifica-
tions, see: (h) Mbaye, M. D.; Renaud, J.-L.; Demerseman, B.;
Bruneau, C. Chem. Commun. 2004, 1870. (i) Onitsuka, K.; Okuda,
H.; Sasai, H. Angew. Chem. Int. Ed. 2008, 47, 1454. For represen-
tative examples on Ir-catalyzed allylic etherifications, see:
(j) Kiener, C. A.; Shu, C.; Incarvito, C.; Hartwig, J. F. J. Am. Chem.
Soc. 2003, 125, 14272. (k) Shu, C.; Hartwig, J. F. Angew. Chem.
Int. Ed. 2004, 43, 4794. (l) Welter, C.; Dahnz, A.; Brunner, B.;
Streiff, S.; Dübon, P.; Helmchen, G. Org. Lett. 2005, 7, 1239.
(m) Kimura, M.; Uozumi, Y. J. Org. Chem. 2007, 72, 707.
(n) Roggen, M.; Carreira, E. M. Angew. Chem. Int. Ed. 2011, 50,
5568.
1H NMR (400 MHz, CDCl3): δ (E isomer) = 7.74–7.55 (m, 2 H), 7.47–
7.35 (m, 2 H), 6.70 (dd, J = 16.3, 5.2 Hz, 1 H), 5.63 (dd, J = 16.4, 1.6 Hz,
1 H), 4.59 (d, J = 12.4 Hz, 1 H), 4.54 (d, J = 12.5 Hz, 1 H), 4.12 (qdd, J =
6.6, 5.2, 1.6 Hz, 1 H), 1.35 (d, J = 6.5 Hz, 3 H); δ (Z isomer) = 7.66–7.55
(m, 2 H), 7.49–7.44 (m, 2 H), 6.45 (dd, J = 11.1, 8.6 Hz, 1 H), 5.48 (dd,
J = 11.1, 0.9 Hz, 1 H), 4.59 (d, J = 12.2 Hz, 1 H), 4.52 (d, J = 12.0 Hz, 1 H),
4.50 (m, 1 H), 1.39 (d, J = 6.4 Hz, 3 H).
13C NMR (101 MHz, CDCl3): δ (E isomer) = 155.5, 141.8, 130.3 (q, J =
32.4 Hz), 127.6, 125.6 (q, J = 3.8 Hz), 124.2 (q, J = 272.0 Hz), 117.0,
100.0, 74.4, 70.3, 203.; δ (Z isomer) = 155.4, 141.9, 130.2 (d, J = 32.4
Hz), 127.8, 125.6 (q, J = 3.9 Hz), 125.3 (m), 115.2, 100.9, 74.2, 70.6,
20.7.
19F NMR (376 MHz, CDCl3): δ = –62.6.
HRMS (ESI): m/z [M + H]+ calcd for C13H13F3NO: 256.0944; found:
256.0938.
Funding Information
(8) For representative examples of intermolecular oxidative allylic
etherifications using alkenes as latent electrophiles, see:
(a) Tiecco, M.; Testaferri, L.; Tingoli, M.; Bagnoli, L.; Santi, C.
J. Chem. Soc., Chem. Commun. 1993, 637. (b) Tomita, R.; Mantani,
K.; Hamasaki, A.; Ishida, T.; Tokunaga, M. Chem. Eur. J. 2014, 20,
This work was financially supported by the German Research Foun-
dation [DFG, Emmy Noether Fellowship to A.B. (BR-4907/1-1)], the
Lower Saxony Ministry for Science and Culture (Georg-Christoph-
Lichtenberg Fellowship to K.R.), and the Fonds der Chemischen Indus-
trie (Ph.D. Fellowship to S.O.).
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© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K

K
K. Rode et al.
Feature
Synthesis
9914. (c) Liron, F.; Oble, J.; Lorion, M. M.; Poli, G. Eur. J. Org.
Chem. 2014, 5863. (d) Li, C.; Li, M.; Li, J.; Liao, J.; Wu, W.; Jiang,
H. J. Org. Chem. 2017, 82, 10912. For representative examples of
intramolecular oxidative allylic etherifications using simple
alkenes as latent electrophiles, see: (e) Semmelhack, M. F.; Kim,
C. R.; Dobler, W.; Meier, M. Tetrahedron Lett. 1989, 30, 4925.
(f) Rönn, M.; Bäckvall, J.-E.; Andersson, P. G. Tetrahedron Lett.
1995, 36, 7749. (g) Trend, R. M.; Ramtohul, Y. K.; Stoltz, B. M.
J. Am. Chem. Soc. 2005, 127, 17778. (h) Guo, R.; Huang, J.; Huang,
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© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–K