Visible-Light-Induced Radical Cascade Cyclizations of 1,7-Enynes with Sulfinic Acids: Direct Access to Sulfonated Chromanes and Sulfonated Tetrahydroquinolines under Metal-Free Conditions

Article abstract of DOI:10.1002/adsc.202000846

Visible-light-induced strategy to access sulfonated chromanes and sulfonated 1,2,3,4-tetrahydroquinolines via a radical cascade cyclization of 1-(arylethynyl)-2-(vinyloxy)benzenes and N-allyl-2-(arylethynyl)anilines with aromatic and aliphatic sulfinic acids has been developed. In the presence of TBHP (7.5 mol%) as an oxidant and Eosin Y (3.0 mol%) as a photocatalyst, the reactions undergo smoothly to afford the corresponding products in good yields at room temperature under metal-free conditions. This transformation features low loading of TBHP, mild reaction conditions, simple operation, broad functional-group tolerance, and good yields of products. (Figure presented.).

Full text of DOI:10.1002/adsc.202000846

Title: Visible-Light-Induced Radical Cascade Cyclizations of 1,7-
Enynes with Sulfinic Acids: Direct Access to Sulfonated
Chromanes and Sulfonated Tetrahydroquinolines under Metal-
Free Conditions
Authors: Qi Liu, Yousheng Mei, Lei Wang, Yongmin Ma, and Pinhua Li
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To be cited as: Adv. Synth. Catal. 10.1002/adsc.202000846
Link to VoR: https://doi.org/10.1002/adsc.202000846

10.1002/adsc.202000846
Advanced Synthesis & Catalysis
FULL PAPER
DOI: 10.1002/adsc.200((will be filled in by the editorial staff))
Visible-Light-Induced Radical Cascade Cyclizations of
1,7-Enynes with Sulfinic Acids: Direct Access to Sulfonated
Chromanes and Sulfonated Tetrahydroquinolines under
Metal-Free Conditions
Qi Liu,a,b Yousheng Mei,b Lei Wang,a,b,c,* Yongmin Ma,a,c and Pinhua Lib,c,*
a
Advanced Research Institute and Department of Chemistry, Taizhou University, Taizhou, Zhejiang, 318000
People’s Republic of China, Phone: (+86)-576-8866-0354; E-mail: leiwang@chnu.edu.cn
Department of Chemistry, Huaibei Normal University, Huaibei, Anhui 235000, People’s Republic of China
b
Fax: (+86)-561-309-0518; Phone: (+86)-561-380-2069; E-mail: pphuali@126.com
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai 200032,
c
People’s Republic of China
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.200######.((Please
delete if not appropriate))
corresponding products in good yields at room
temperature under metal-free conditions. This
transformation features low loading of TBHP, mild
reaction conditions, simple operation, broad
Abstract: A visible-light-induced strategy to access
sulfonated
1,2,3,4-tetrahydroquinolines via
chromanes
and
a
sulfonated
radical cascade
cyclization of 1-(arylethynyl)-2-(vinyloxy)benzenes and
N-allyl-2-(arylethynyl)anilines with aromatic and aliphatic
sulfinic acids has been developed. In the presence of TBHP
(7.5 mol%) as an oxidant and Eosin Y (3.0 mol%) as a
photocatalyst, the reactions undergo smoothly to afford the
functional-group tolerance, and good yields of products.
Key words: 1,7-enynes; chromanes; tetrahydroquinolines;
visible-light photocatalysis; Eosin Y; sulfinic acids
reported sulfonyl radical-induced bicyclization of O‐
tethered 1,7‐ enynes with aryl sulfonhydrazides for
accessing tetracyclic chromen-2-ones.[3e]
The sulfone-containing compounds have been
frequently found in the natural products,
pharmaceuticals and biologically active molecules,
which are used for anti-HIV, anti-cancer,
Introduction
The free radical tandem cyclization is a powerful
platform for the rapid construction of complicated
carbocyclic and heterocyclic architectures in a
chemoselective and atom-economical manner.[1] In
the last two decades, the considerable attention in this
field has focused on the radical addition and cascade
cyclization, in which free radical species add to
unsaturated chemical bonds, followed by an
intramolecular cyclization to access cyclic
frameworks.[2] 1,n-Enynes, including 1,5-enynes,
1,6-enynes, and 1,7-enynes are proven to be the
excellent skeletons for the synthesis of cyclic
compounds. The reactions are initiated by an addition
of carbon-centered radicals,[3] oxygen-centered
anti-psoriasis,
anti-inflammatory
epresentative
and
medicinally
anti-depressant.[9]
R
interesting molecules containg sulfone unit, shown
in Figure 1, are DPP-IV inhibitor,[10a] Eletriptan as
5-HT1-like
agonists,[10b]
Amisulfride
as
psychotropic agents,[10c] Dapsone as treatment adjunct
radicals,[4]
sulfur-centered
nitrogen-centered
radicals,[5]
radicals,[6]
phosphorus-centered
radicals,[7] or azide-centered radicals,[8] to the
carbon-carbon multiple bond within substrates, and
subsequently undergo the intramolecular radical
cyclization. It should be noted that Tu’s group
Figure 1. Representative medicines containg sulfone unit.
1
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10.1002/adsc.202000846
Advanced Synthesis & Catalysis
in ARDS,[10d] and motif in -3 adrenergic receptor
agonists.[10e] They have been also applied as the
building blocks in organic synthesis.[11] Therefore, the
synthesis of sulfones has gained considerable
attention of chemists and one of the most classic
method is based on the addition of sulfonyl radicals
to alkenes and alkynes.[12] Comparing with sulphonyl
halides as sulfonylation reagents, sulfinic acids and
their salts are relatively stable and versatile
intermediates in organic synthesis and the
considerable efforts have been devoted to the
synthesis of organic sulfones using aryl(alkyl)sulfinic
acids (salts) as sulfonylation agents. As a result, the
addition of sulfonyl radicals to carbon-carbon
multiple bonds for the synthesis of functionalized
sulfones have gained a variety of achievements in
recent years.[13]
3,4-dihydroquinolin-2(1H)-one and 2-chromanone
skeletons.[18a] Moreover, the use of sulfinic acids in
sulfonyl
radical
addition/cyclization
of
alkynes/enynes under visible light irradiation was
also extensive investigated.[18b-d] However, most of
these reported methods require stoichiometric
amounts of an oxidant (typically TBHP) and often
employ enynes containing Michael acceptor-type
alkenes. Herein, we wish to report
visible-light-induced synthesis of sulfonated
chromane derivatives via radical cascade
a
a
cyclization of 1-(arylethynyl)-2-(vinyloxy)benzenes
and N-allyl-2-(arylethynyl)anilines having 1,7-enyne
moiety with sulfinic acids using Eosin Y (3.0 mol%)
as a photocatalyst in the presence of TBHP (7.5
mol%) as an oxidant, providing the corresponding
products in good yields at room temperature under
metal-free conditions (Scheme 1f). It provides a
direct protocol for the synthesis of a diverse range of
Recently, 1,7-enynes have been recognized as
highly versatile substrates for the construction of
functionalized benzofurans and benzopyrans with
structural diversity and complexity via a radical
induced tandem cyclization. For example, Tang and
co-workers reported a Au-catalyzed synthesis of
sulfonated
chromanes
and
sulfonated
1,2,3,4-tetrahydroquinolines in an efficient way.
functionalized
dihydrobenzofuran-3-ones
from
1,7-enynes via a [2,3]-sigmatropic rearrangement of
oxonium ylides in the presence of pyridine N-oxide
(Scheme 1a).[14] In addition, Arisawa et al developed
a Ru-hydride catalyzed cycloisomerization of aryl
enol ether and silylalkynes to yield 2,3-disubstituted
benzofurans by two steps. Under the catalysis of
Ru-hydride, the aryl enol ether finished the migration
of
olefinic
double
bonds
to
complete
cycloisomerization, followed by a Grubbs's catalysis
to the desired products with vinyl and
trimethylsilylmethyl groups on the 2- and 3-positions
(Scheme 1b).[15] Recently, Zi’s group described a
Re(I)-catalyzed carboalkoxylation of 1,7-enynes for
the preparation of C3-substituted benzofurans, in
which Re plays an important role of a π acid catalyst
to activate alkynes, followed by a charge-accelerated
[3,3]-sigmatropic rearrangement (Scheme 1c).[16] It
should be noted that Jiang reported an elegant work
on a Cu-catalyzed cascade cyclization of 1,7-enynes
with Togni’s reagent, carbon dioxide, and amines,
providing a direct and efficient route to a range of
trifluoromethyl-substituted carbamates (Scheme
1d).[17a] In addition, Jiang also developed
Pd-catalyzed tandem intermolecular cyclization of
1-(allyloxy)-2-ethynylbenzenes with isocyanides and
water, generating 2,3-difunctionalized benzofurans
a
Scheme 1. The transformations of 1-(allyloxy)-2-(ethynyl)benzenes
and N-allyl-2-(arylethynyl)anilines.
Results and Discussion
including
2-benzofurylquinoxalines,
benzofuran-3-α-ketoesters and benzofuryl ynediones
(Scheme 1e).[17b] It should be noted that Li, Guo and
co-workers reported a metal-free oxidative 6-exo-dig
cyclization of N- and O-tethered 1,7-enynes triggered
by addition of sulfonyl radicals generated in situ from
sulfinic acids, enabling the assembly of
Initially, 1-(allyloxy)-2-(phenylethynyl)benzene (1a)
and 4-methylbenzenesulfinic acid (2a) were selected
as the model substrates for optimization of the
reaction conditions and the results were listed in
Table 1. When the model reaction of 1a with 2a was
performed in the presence of Eosin Y (3.0 mol%) as a
2
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10.1002/adsc.202000846
Advanced Synthesis & Catalysis
photoredox catalyst, tert-butyl hydroperoxide (TBHP,
when the amount of TBHP decreased from 1.0 equiv.
to 0.5 equiv., the yield of 3a increased from 66% to
75% (Table 1, entry 8). Continuing to reduce the
amount of TBHP to 25 mol% or even 7.5 mol%, the
yield of 3a was unchanged (Table 1, entries 9−11). In
the absence of visible light or Eosin Y, the model
reaction can not proceed to produce the target product
3a (Table 1, entries 12 and 13). Furthermore, the
desired product 3a was obtained in 18% yield in the
absence of TBHP (Table 1, entry 14). When the
model reaction was irradiated under sunlight, 3a was
isolated in 62% yield (Table 1, entry 15). In addition,
the effect of solvent on the reaction was also
examined, and the results indicated that DCE is the
best one amongst the tested solvents including EtOH,
DMSO, THF, CH2Cl2, toluene, CH3CN and H2O.
With the optimized conditions in hand, we next
explored the scope of the oxidative radical cascade
cyclization. The results are shown in Scheme 2. First,
1.0
equiv.)
as
an
oxidant
and
DCE
(1,2-dichloroethane) as solvent at room temperature
under air atmosphere with irradiation of a green LED
(530–535 nm, 3 W) for 12 h, to our delight, the
reaction generated the corresponding product 3a in
45% yield (Table 1, entry 1). An improved yield
(66%) of 3a was obtained when N2 atmosphere was
used instead of air atmosphere (Table 1, entry 2).
When H2O2 was used as the oxidant instead of TBHP,
the model reaction afforded the desired product 3a in
27% yield (Table 1, entry 3). Other oxidants, such as
K2S2O8 and DTBP (di-tert-butyl peroxide) led to
trace amount of 3a only (Table 1, entries 4 and 5).
For improvement of the desired product yield,
-
Ru(phen)3Cl2
and
Mes-Acr-Me+ClO4
(9-mesityl-10-methylacridine), as the photocatalysts
were examined, providing no reactivity for the
reaction (Table 1, entries 6 and 7). It is surprising that
Table 1.
Optimization of the reaction conditions.[a]
a
variety of 1-(allyloxy)-2-(arylethynyl)benzene
derivatives were examined under the standard
conditions, indicating a broad tolerance of substituted
groups on the aromatic rings. Unsubstituted 1 (1a)
and substrates 1 with an electron-donating group
(such as MeO, Me, Et, n-Pr, n-Bu and t-Bu) or an
electron-withdrawing group (F and Br) at the
para-position of the benzene rings in aromatic alkyne
moiety (R2), reacted with 4-methylbenzenesulfinic
Entry
1
Photocatalyst
Eosin Y
Eosin Y
Eosin Y
Eosin Y
Eosin Y
Ru(phen)3Cl2
Mes-Acr+ClO4
Eosin Y
Eosin Y
Eosin Y
Eosin Y
Eosin Y
–
Oxidant
TBHP
TBHP
H2O2
Light source
Green LED
Green LED
Green LED
Green LED
Green LED
Blue LED
Yield (%)[b]
45[c]
66
2
3
27
4
K2S2O8
DTBP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
–
Trace
Trace
Trace
Trace
75[d]
75[e]
75[f]
5
6
-
7
Blue LED
8
Green LED
Green LED
Green LED
Green LED
9
10
11
12
13
14
15
75[g]
NR
–
Green LED
Green LED
Sunlight
NR
Eosin Y
Eosin Y
18
TBHP
62
[a]
Reaction conditions: 1-(allyloxy)-2-(phenylethynyl)benzene
(1a, 0.10 mmol), 4-methylbenzenesulfinic acid (2a, 0.15 mmol),
photocatalyst (3.0 mol%), oxidant (0.10 mmol, 1.0 equiv.), DCE
(3.0 mL) at room temperature under N2 atmosphere with LED
irradiation (3 W) for 12 h. NR = no reaction. Green LED (530–
535 nm). Blue LED (450–455 nm).
[b] Isolated yield.
[c] Air atmosphere.
[d] TBHP (0.5 equiv.).
[e] TBHP (25 mol%).
[f] TBHP (15 mol%).
[g] TBHP (7.5 mol%).
Scheme 2. The scope of substrates 1 [Reaction conditions: 1 (0.10 mmol),
2a (0.15 mmol), Eosin Y (3.0 mol%), TBHP (7.5 mol%), and DCE (3.0
mL) at room temperature in N2 atmosphere under green LED (530–535
nm, 3 W) irradiation for 12 h; isolated yield of the product; [a]isolated
yield of product 3a in 5 mmol scale].
3
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10.1002/adsc.202000846
Advanced Synthesis & Catalysis
acid (2a) smoothly to afford the corresponding
products 3a−3j in 63−81% yields. Furthermore, a
gram-scale (up to 5.0 mmol scale) synthesis of 3a
was achieved in 63% isolated yield. Meanwhile,
substrates 1 containing an electron-rich group (MeO)
or an electron-withdrawing group (F, Cl and Br) on
the meta- or ortho-position of phenylacetylene (R2),
underwent the tandem reaction with 2a to generate
the desired products 3k−3q in 76−86% yields,
neglecting steric effect. Furthermore, the reaction of 1,
which is introduced a 2-naphthylethynyl moiety, with
2a led to the according product 3r in 65% yield. On
the other hand, a variety of substituted groups (R1) on
the aromatic rings were investigated. For the
Unfortunately, thiophene-2-sulfinic acid was
attempted under the standard reaction conditions, and
no desired product was obtained.
representative
substituents
(R1),
including
electron-donating group (Me) and halogens (F, Cl
and Br) on the aromatic rings, gave the anticipated
products 3s−3w in 74−83% yields. It should be noted
that substrate 1 with a thienylethynyl group was used
to react with 2a, providing 3x in an acceptable yield
(67%). Product 3y was obtained in 56% yield from
the suitable substrates, and its stereochemistry was
confirmed by single crystal X-ray diffraction analysis
(see: Supporting Information),[19] leading to favorable
E-isomer. Moreover, the influence of substitution on
the alkene moiety was investigated using
(E)-1-(but-2-en-1-yloxy)-2-(phenylethynyl)benzene
(1z), generating the desired product 3z in 51% yield.
As an example of internal alkene on 1,7-enyne,
1-(cinnamyloxy)-2-(phenylethynyl)benzene reacted
with 2a, no desired product was obtained. However,
Scheme 3. Substrate scope of sulfinic acids 2 [Reaction
conditions: 1a (0.10 mmol), 2 (0.15 mmol), Eosin Y (3.0 mol%),
TBHP (7.5 mol%), and DCE (3.0 mL) at room temperature in N2
atmosphere under green LED (530–535 nm, 3 W) irradiation for
12 h; isolated yield of the product].
alkyl-substituted
alkynes,
such
as
1-(allyloxy)-2-(cyclopropylethynyl)benzene
and
1-(allyloxy)-2-(hex-1-yn-1-yl)benzene were used as
substrates to react with 2a under the present reaction
conditions, but failed.
Subsequently, a variety of sulfinic acids were
examined under the standard reaction conditions and
the results are summarized in Scheme 3. A range of
arylsulfinic
acids
including
hydrogen,
an
electron-withdrawing group (F, Cl, Br and I) or an
electron-donating group (Me) on the aryl rings
underwent the transformations well with 1a to
generate the corresponding products (3aa–3aj) in 59–
83% yields. It should be noted that sterically hindered
substituted arylsulfinic acids, including 2-chloro- and
2-bromobenzenesulfinic acids, are suitable substrates
for the radical cascade cyclizations, thereby leading
to the desired products 3ai and 3aj in 68% and 64%
yield, respectively. Furthermore, disubstituted
arylsulfinic acid, such as 3,5-dichlorobenzenesulfinic
acid, was also a suitable sulfonylation reagent for this
transformation, providing 65% yield of the product
3ak. To our delight, when the scope of sulfinic acid
was switched to an aliphatic analogue, the anticipant
product 3al was isolated in 45% yield by use of
n-butylsulfinic acid as the sulfonylation reagent.
Scheme 4. The reactions of substrates 4 with sulfinic acids 2
[Reaction conditions: 4 (0.10 mmol), 2 (0.15 mmol), Eosin Y
(3.0 mol%), TBHP (7.5 mol%), and DCE (3.0 mL) at room
temperature in N2 atmosphere under green LED (530–535 nm, 3
W) irradiation for 12 h; isolated yield of the product].
To further extend the substrate scope, N-tethered
enynes,
such
as
N-allyl-4-methyl-N-(2-(phenylethynyl)phenyl)benzen
e-sulfonamide,
N-allyl-N-(2-((4-chlorophenyl)ethynyl)phenyl)-4-met
4
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10.1002/adsc.202000846
Advanced Synthesis & Catalysis
of HO- with arylsulfinic acid (2) to produce sulfonyl
radical (B) for the repeat sulfonylation and the
formation of Eosin Y to complete the photocatalyst
cycle through a SET process. It should be noted that
the key radical intermediates C and/or D could be
trapped by 1,2-diphenylethene (4), providing adducts
5 and/or 6, confirmed by HRMS analysis (ESI for
details).
hylbenzenesulfonamide
N-allyl-N-(5-bromo-2-(phenylethynyl)phenyl)-4-met
hylbenzenesulfonamide were as used as substrates to
and
react
with
4-methylbenzenesulfinic
acid,
and
the
4-bromobenzenesulfinic
3-chlorobenzenesulfinic
corresponding products 5a5e in 5880% yields, as
shown in Scheme 4.
acid
providing
acid,
To clarify the mechanism of this cascade
cyclization,
a
radical-trapping
reagent,
2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), was
added to the model reaction and it was completely
inhibited, indicating that free-radical intermediates
were involved in the reaction (ESI for details). Based
on our observations and literature, a plausible
mechanism is proposed in Scheme 5. Firstly, the
excited-state Eosin Y* is formed under visible-light
irradiation, which undergoes a reaction with TBHP
via SET process to generate a hydroxide anion (HO-)
and tert-butyloxy radical (t-BuO) along with the
formation of Eosin Y+. Then the obtained t-BuO
abstracts a hydrogen from arylsulfinic acid (2) to
generate the corresponding sulfonyl radical (B),
which takes an addition to carbon-carbon double
bond of 1a to afford an alkyl radical (C), followed by
an intramolecular radical cyclization with
carbon-carbon triple bond of alkyne via a 6-exo-dig
cyclization, forming vinyl intermediate (D).[2b,6f]
Finally, intermediate (D) gets a hydrogen from 2 to
afford the desired product 3 along with the formation
of B for next run. On the other hand, the generated
Eosin Y+ reacts with A, which is from the reaction
Conclusion
In
visible-light-induced strategy to access sulfonated
chromanes and sulfonated
conclusion,
we
have
developed
a
1,2,3,4-tetrahydroquinolines via radical cascade
cyclization of 1-(arylethynyl)-2-(vinyloxy)benzenes
and
N-allyl-2-(arylethynyl)anilines with sulfinic
acids under metal-free conditions. In the presence of
TBHP (7.5 mol%) as an oxidant and Eosin Y (3.0
mol%) as a photocatalyst, the reactions undergo
smoothly to afford the corresponding products in
good yields under green LED irradiation and nitrogen
atmosphere at room temperature. This transformation
features low loading of TBHP, mild reaction
conditions, simple operation, broad functional-group
tolerance, and high efficiency. Its detailed reaction
mechanism and further applications are underway in
our laboratory.
Experimental Section
General Considerations
The 1H NMR and 13C NMR spectra were recorded on a
400 or a 600 MHz Bruker FT-NMR spectrometer (600/150
MHz or 400/100 MHz, respectively), and 19F NMR spectra
were recorded on
a 600 MHz Bruker FT-NMR
spectrometer (565 MHz). All chemical shifts are given as δ
value (ppm) with reference to tetramethylsilane (TMS) as
an internal standard. The peak patterns are indicated as
follows: s, singlet; d, doublet; t, triplet; m, multiplet; q,
quartet. The coupling constants, J, are reported in Hertz
(Hz). High resolution mass spectroscopy data of the
product were collected on an Agilent Technologies 6540
UHD Accurate-Mass Q-TOF LC/MS (ESI). All the
solvents and commercially available reagents were
purchased from commercial suppliers. Products were
purified by flash chromatography on 200–300 mesh silica
gels, SiO2.
Typical Procedure for the Synthesis of 3a
A 5 mL oven-dried reaction vessel equipped with a
magnetic
stirrer
bar
was
charged
with
1-(allyloxy)-2-(phenylethynyl)benzene (1a, 0.10 mmol),
4-methylbenzenesulfinic acid (2a, 0.15 mmol), Eosin Y
(3.0 mol%), TBHP (7.5 mol%), and DCE (3.0 mL). The
reaction vessel was exposed to green LED (530–535 nm, 3
Scheme 5. The proposed mechanism.
5
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10.1002/adsc.202000846
Advanced Synthesis & Catalysis
W) irradiation at room temperature in N2 atmosphere with
stirring for 12 h. After completion of the reaction, the
mixture was concentrated to yield the crude product, which
was further purified by flash chromatography (silica gel,
petroleum ether/ethyl acetate) to give the desired product
3a (29.4 mg, 75% yield).
129.4, 128.9, 128.1, 128.0, 125.0, 123.2, 121.4, 121.3,
117.3, 67.0, 54.5, 29.9, 28.6, 21.6, 15.4. HRMS (ESI)
([M+Na]+) Calcd. For [C26H26NaO3S]+: 441.1495, Found:
441.1497.
(E)-4-(4-(n-Propyl)benzylidene)-3-(tosylmethyl)chroma
n
(3e):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (28.7 mg, 66%
yield). H NMR (600 MHz, CDCl3) δ: 7.80 (d, J = 7.8 Hz,
Characterization data for the products
1
(E)-4-Benzylidene-3-(tosylmethyl)chromane
Isolated by column chromatography (EtOAc/petroleum
ether = 1:20); white solid (29.4 mg, 75% yield). H NMR
(3a):
2H), 7.47 (dd, J1 = 1.2 Hz, J2 = 7.8 Hz, 1H), 7.34 (d, J =
7.8 Hz, 2H), 7.17–7.14 (m, 3H), 7.11–7.10 (m, 2H), 6.91–
6.87 (m, 3H), 4.77 (dd, J1 = 1.2 Hz, J2 = 10.8 Hz, 1H), 3.97
(d, J = 11.4 Hz, 1H), 3.84 (dd, J1 = 1.8 Hz, J2 = 11.4 Hz,
1H), 3.65–3.61 (m, 1H), 3.12 (d, J = 14.4 Hz, 1H), 2.58 (t,
J = 7.8 Hz, 2H), 2.45 (s, 3H), 1.69–1.62 (m, 2H), 0.96 (t, J
= 7.2 Hz, 3H). 13C NMR (150 MHz, CDCl3) δ: 153.6,
144.7, 141.9, 137.0, 133.1, 131.6, 130.0, 129.3, 128.8,
128.7, 127.9, 125.0, 123.2, 121.3, 121.2, 117.3, 66.9, 54.4,
37.7, 29.8, 24.3, 21.6, 13.8. HRMS (ESI) ([M+Na]+) Calcd.
For [C27H28NaO3S]+: 455.1651, Found: 455.1650.
1
(600 MHz, CDCl3) δ: 7.77 (d, J = 7.8 Hz, 2H), 7.49 (d, J =
7.8 Hz, 1H), 7.32–7.28 (m, 4H), 7.26–7.23 (m, 3H), 7.18 (t,
J = 7.8 Hz, 1H), 6.92–6.88 (m, 3H), 4.76 (d, J = 11.4 Hz,
1H), 3.99 (d, J = 11.4 Hz, 1H), 3.80 (d, J = 10.8 Hz, 1H),
3.64–3.60 (m, 1H), 3.10 (d, J = 14.4 Hz, 1H), 2.45 (s, 3H).
13C NMR (150 MHz, CDCl3) δ: 153.7, 144.8, 136.8, 135.7,
132.4, 130.0, 129.5, 128.8, 128.5, 127.8, 127.2, 125.0,
123.2, 121.2, 121.1, 117.3, 67.0, 54.5, 29.8, 21.6. HRMS
(ESI) ([M+Na]+) Calcd. For [C24H22NaO3S]+: 413.1182,
Found: 413.1184.
(E)-4-(4-(n-Butyl)benzylidene)-3-(tosylmethyl)chroman
(3f):
Isolated
by
column
chromatography
(E)-4-(4-Methoxybenzylidene)-3-(tosylmethyl)chroman
(EtOAc/petroleum ether = 1:20); white solid (28.6 mg, 64%
yield). H NMR (600 MHz, CDCl3) δ: 7.81 (d, J = 7.8 Hz,
(3b):
Isolated
by
column
chromatography
1
(EtOAc/petroleum ether = 1:20); white solid (33.8 mg, 80%
2H), 7.48 (dd, J1 = 1.2 Hz, J2 = 7.8 Hz, 1H), 7.35 (d, J =
8.4 Hz, 2H), 7.18–7.15 (m, 3H), 7.12 (d, J = 7.8 Hz, 2H),
6.92–6.87 (m, 3H), 4.77 (dd, J1 = 1.8 Hz, J2 = 11.4 Hz, 1H),
3.98 (d, J = 11.4 Hz, 1H), 3.85 (dd, J1 = 1.8 Hz, J2 = 11.4
Hz, 1H), 3.66–3.61 (m, 1H), 3.12 (d, J = 14.4 Hz, 1H),
2.61 (t, J = 7.8 Hz, 2H), 2.46 (s, 3H), 1.64–1.59 (m, 2H),
1.41–1.35 (m, 2H), 0.95 (t, J = 7.2 Hz, 3H). 13C NMR (150
MHz, CDCl3) δ:153.6, 144.8, 142.2, 137.0, 133.0, 131.7,
130.0, 129.3, 128.8, 128.7, 127.9, 125.0, 123.2, 121.4,
121.2, 117.3, 67.0, 54.5, 35.3, 33.4, 29.8, 22.3, 21.6, 13.9.
HRMS (ESI) ([M+Na]+) Calcd. For [C28H30NaO3S]+:
469.1808, Found: 469.1806.
1
yield). H NMR (600 MHz, CDCl3) δ: 7.81 (d, J = 7.2 Hz,
2H), 7.48 (d, J = 7.8 Hz, 1H), 7.35 (d, J = 7.8 Hz, 2H),
7.23 (d, J = 7.8 Hz, 2H), 7.17 (t, J = 7.8 Hz, 1H), 6.92–
6.85 (m, 5H), 4.75 (d, J = 10.8 Hz, 1H), 3.99 (d, J = 10.8
Hz, 1H), 3.86 (s, 1H), 3.84 (s, 3H), 3.64 (t, J = 12.6 Hz,
1H), 3.10 (d, J = 14.4 Hz, 1H), 2.46 (s, 3H). 13C NMR
(150 MHz, CDCl3) δ: 158.9, 153.5, 144.9, 137.0, 130.8,
130.3, 130.0, 129.2, 128.3, 127.9, 124.9, 122.9, 121.5,
121.3, 117.3, 114.1, 67.1, 55.3, 54.5, 29.8, 21.6. HRMS
(ESI) ([M+Na]+) Calcd. For [C25H24NaO4S]+: 433.1288,
Found: 433.1288.
(E)-4-(4-Methylbenzylidene)-3-(tosylmethyl)chroman
(E)-4-(4-(tert-Butyl)benzylidene)-3-(tosylmethyl)chrom
an (3g): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (28.3 mg, 63%
(3c):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (28.0 mg, 69%
1
yield). H NMR (600 MHz, CDCl3) δ: 7.79 (d, J = 8.4 Hz,
1
yield). H NMR (600 MHz, CDCl3) δ: 7.84 (d, J = 7.8 Hz,
2H), 7.47 (d, J = 7.8 Hz, 1H), 7.33 (d, J = 8.4 Hz, 2H),
7.18–7.09 (m, 5H), 6.92–6.87 (m, 3H), 4.76 (d, J = 11.4
Hz, 1H), 3.97 (d, J = 11.4 Hz, 1H), 3.81 (d, J = 11.4 Hz,
1H), 3.64–3.60 (m, 1H), 3.10 (d, J = 14.4 Hz, 1H), 2.45 (s,
3H), 2.35 (s, 3H). 13C NMR (150 MHz, CDCl3) δ: 153.6,
144.7, 137.1, 136.9, 132.8, 131.7, 130.0, 129.3, 129.3,
128.8, 127.9, 124.9, 123.2, 121.3, 121.2, 117.3, 67.0, 54.5,
29.8, 21.6, 21.2. HRMS (ESI) ([M+Na]+) Calcd. For
[C25H24NaO3S]+: 427.1338, Found: 427.1339.
2H), 7.48 (d, J = 7.8 Hz, 1H), 7.37–7.33 (m, 4H), 7.24–
7.22 (m, 2H), 7.17 (t, J = 7.5 Hz, 1H), 6.92–6.87 (m, 3H),
4.78 (d, J = 11.4 Hz, 1H), 3.98 (d, J = 11.4 Hz, 1H), 3.90
(d, J = 11.4 Hz, 1H), 3.67–3.63 (m, 1H), 2.47 (s, 3H), 1.34
(s, 9H). 13C NMR (150 MHz, CDCl3) δ: 153.6, 150.4,
144.8, 137.1, 132.8, 131.7, 130.0, 129.4, 128.8, 128.0,
125.6, 125.0, 123.1, 121.4, 121.2, 117.3, 67.0, 54.4, 34.6,
31.2, 29.8, 21.7. HRMS (ESI) ([M+Na]+) Calcd. For
[C28H30NaO3S]+: 469.1808, Found: 469.1806.
(E)-4-(4-Ethylbenzylidene)-3-(tosylmethyl)chroman
(E)-4-(4-Fluorobenzylidene)-3-(tosylmethyl)chroman
(3d):
Isolated
by
column
chromatography
(3h):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (28.1 mg, 67%
(EtOAc/petroleum ether = 1:20); white solid (33.1 mg, 81%
1
yield). H NMR (600 MHz, CDCl3) δ: 7.81 (d, J = 8.4 Hz,
1
yield). H NMR (600 MHz, CDCl3) δ: 7.75 (d, J = 7.8 Hz,
2H), 7.48 (dd, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H), 7.35 (d, J =
8.4 Hz, 2H), 7.19–7.13 (m, 5H), 6.92–6.88 (m, 3H), 4.77
(dd, J1 = 1.8 Hz, J2 = 11.4 Hz, 1H), 3.98 (d, J = 10.8 Hz,
1H), 3.85 (dd, J1 = 1.2 Hz, J2 = 10.8 Hz, 1H), 3.66–3.62 (m,
1H), 3.13 (d, J = 14.4 Hz, 1H), 2.66 (q, J = 7.8 Hz, 2H),
2.46 (s, 3H), 1.26 (t, J = 7.8 Hz, 3H). 13C NMR (150 MHz,
CDCl3) δ: 153.6, 144.8, 143.5, 137.0, 133.1, 131.7, 130.0,
2H), 7.47 (d, J = 7.8 Hz, 1H), 7.32 (d, J = 7.8 Hz, 2H),
7.21–7.17 (m, 3H), 6.97 (t, J = 8.4 Hz, 2H), 6.93–6.88 (m,
3H), 4.75 (d, J = 11.4 Hz, 1H), 3.98 (d, J = 11.4 Hz, 1H),
3.70 (d, J = 10.8 Hz, 1H), 3.64–3.60 (m, 1H), 3.04 (d, J =
11.4 Hz, 1H), 2.46 (s, 3H). 13C NMR (150 MHz, CDCl3) δ:
161.8 (d, J = 246.5 Hz), 153.6, 144.9, 136.6, 132.5, 131.8
6
This article is protected by copyright. All rights reserved.

10.1002/adsc.202000846
Advanced Synthesis & Catalysis
(d, J = 3.2 Hz), 130.5 (d, J = 7.8 Hz), 130.0, 129.6, 127.8,
124.9, 122.0, 121.3, 120.9, 117.4, 115.5 (d, J = 21.2 Hz),
67.0, 54.4, 29.7, 21.5. 19F NMR (565 MHz, CDCl3) δ:
-113.91. HRMS (ESI) ([M+Na]+) Calcd. For
[C24H21FNaO3S]+: 431.1088, Found: 431.1091.
133.6, 130.0 (d, J = 8.6 Hz), 129.9, 129.8, 127.7, 124.9,
124.4 (d, J = 2.4 Hz), 121.8 (d, J = 1.8 Hz), 121.3, 120.6,
117.4, 115.6 (d, J = 21.3 Hz), 114.0 (d, J = 21.2 Hz), 66.9,
54.4, 29.7, 21.5. 19F NMR (565 MHz, CDCl3) δ: -112.31.
HRMS (ESI) ([M+Na]+) Calcd. For [C24H21FNaO3S]+:
431.1088, Found: 431.1086.
(E)-4-(4-Chlorobenzylidene)-3-(tosylmethyl)chroman
(3i):
Isolated
by
column
chromatography
(E)-4-(3-Chlorobenzylidene)-3-(tosylmethyl)chroman
(EtOAc/petroleum ether = 1:20); white solid (28.2 mg, 66% (3m):
Isolated
by
column
chromatography
1
yield). H NMR (600 MHz, CDCl3) δ: 7.76 (d, J = 7.8 Hz,
2H), 7.47 (dd, J1 = 1.2 Hz, J2 = 7.8 Hz, 1H), 7.34 (d, J =
8.4 Hz, 2H), 7.25–7.23 (m, 2H), 7.19 (td, J1 = 1.2 Hz, J2 =
8.4 Hz, 1H), 7.14 (d, J = 8.4 Hz, 2H), 6.93–6.88 (m, 2H),
6.86 (s, 1H), 4.76 (dd, J1 = 1.8 Hz, J2 = 10.8 Hz, 1H), 3.99
(d, J = 10.8 Hz, 1H), 3.69–3.60 (m, 2H), 3.04 (d, J = 13.8
Hz, 1H), 2.48 (s, 3H). 13C NMR (150 MHz, CDCl3) δ:
153.7, 145.0, 136.6, 134.2, 133.2, 133.0, 130.1, 130.0,
129.8, 128.7, 127.9, 125.0, 121.8, 121.3, 120.8, 117.4, 67.0,
54.4, 29.8, 21.6. HRMS (ESI) ([M+Na]+) Calcd. For
[C24H21ClNaO3S]+: 477.0792, Found: 477.0794.
(EtOAc/petroleum ether = 1:20); white solid (34.5 mg,
81% yield). 1H NMR (400 MHz, CDCl3) δ: 7.75 (d, J = 8.4
Hz, 2H), 7.48 (dd, J1 = 1.6 Hz, J2 = 8.0 Hz, 1H), 7.32–7.28
(m, 3H), 7.25–7.13 (m, 4H), 6.94–6.86 (m, 3H), 4.75 (dd,
J1 = 1.6 Hz, J2 = 11.2 Hz, 1H), 4.01 (d, J = 11.2 Hz, 1H),
3.75 (dd, J1 = 1.6 Hz, J2 = 10.8 Hz, 1H), 3.63–3.57 (m, 1H),
3.03 (d, J = 14.4 Hz, 1H), 2.44 (s, 3H). 13C NMR (100
MHz, CDCl3) δ: 153.8, 144.8, 137.6, 136.7, 134.5, 133.8,
130.0, 129.9, 129.8, 128.9, 127.7, 127.3, 126.8, 124.9,
121.6, 121.3, 120.6, 117.5, 67.1, 54.6, 29.7, 21.6. HRMS
(ESI) ([M+Na]+) Calcd. For [C24H21ClNaO3S]+: 447.0792,
Found: 447.0790.
(E)-4-(4-Bromobenzylidene)-3-(tosylmethyl)chroman
(3j):
Isolated
by
column
chromatography
(E)-4-(3-Bromobenzylidene)-3-(tosylmethyl)chroman
(EtOAc/petroleum ether = 1:20); white solid (30.6 mg, 65% (3n):
Isolated
by
column
chromatography
1
yield). H NMR (600 MHz, CDCl3) δ: 7.75 (d, J = 8.4 Hz,
2H), 7.47 (dd, J1 = 1.2 Hz, J2 = 7.8 Hz, 1H), 7.37 (d, J =
8.4 Hz, 2H), 7.33 (d, J = 7.8 Hz, 2H), 7.19 (td, J1 = 1.2 Hz,
J2 = 8.4 Hz, 1H), 7.06 (d, J = 8.4 Hz, 2H), 6.93–6.88 (m,
2H), 6.83 (s, 1H), 4.76 (dd, J1 = 1.8 Hz, J2 = 11.4 Hz, 1H),
3.97 (d, J = 11.4 Hz, 1H), 3.66–3.59 (m, 2H), 3.04 (d, J =
13.8 Hz, 1H), 2.48 (s, 3H). 13C NMR (150 MHz, CDCl3) δ:
153.7, 145.0, 136.5, 134.6, 133.2, 131.6, 130.3, 130.0,
129.8, 127.8, 124.9, 121.8, 121.3, 121.2, 120.7, 117.4, 66.9,
54.3, 29.8, 21.6. HRMS (ESI) ([M+Na]+) Calcd. For
[C24H21BrNaO3S]+: 491.0287, Found: 491.0287.
(EtOAc/petroleum ether = 1:20); white solid (40.5 mg, 86%
yield). H NMR (600 MHz, CDCl3) δ: 7.75 (d, J = 7.8 Hz,
1
2H), 7.47 (d, J = 7.8 Hz, 1H), 7.44 (s, 1H), 7.39 (d, J = 7.2
Hz, 1H), 7.31 (d, J = 7.8 Hz, 2H), 7.20–7.16 (m, 3H),
6.93–6.88 (m, 2H), 6.85 (s, 1H), 4.74 (d, J = 11.4 Hz, 1H),
4.00 (d, J = 10.8 Hz, 1H), 3.76–3.74 (m, 1H), 3.62–3.58
(m, 1H), 3.03 (d, J = 14.4 Hz, 1H), 2.44 (s, 3H). 13C NMR
(150 MHz, CDCl3) δ: 153.8, 144.8, 137.9, 136.7, 133.8,
131.8, 130.2, 130.0, 130.0, 129.9, 127.7, 127.2, 124.9,
122.7, 121.5, 121.3, 120.6, 117.5, 67.1, 54.5, 29.7, 21.6.
HRMS (ESI) ([M+Na]+) Calcd. For [C24H21BrNaO3S]+:
491.0287, Found: 491.0287.
(E)-4-(3-Methoxybenzylidene)-3-(tosylmethyl)chroman
(3k):
Isolated
by
column
chromatography
(E)-4-(2-Methoxybenzylidene)-3-(tosylmethyl)chroman
(EtOAc/petroleum ether = 1:20); white solid (33.6 mg,
80% yield). 1H NMR (400 MHz, CDCl3) δ: 7.75 (d, J = 8.0
Hz, 2H), 7.49 (dd, J1 = 1.6 Hz, J2 = 8.0 Hz, 1H), 7.31 (d, J
= 8.0 Hz, 2H), 7.22–7.16 (m, 2H), 6.93–6.81 (m, 6H), 4.75
(dd, J1 = 2.0 Hz, J2 = 11.2 Hz, 1H), 4.01 (d, J = 11.6 Hz,
1H), 3.87–3.85 (m, 4H), 3.64–3.57 (m, 1H), 3.10 (d, J =
14.0 Hz, 1H), 2.44 (s, 3H). 13C NMR (100 MHz, CDCl3) δ:
159.8, 153.7, 144.7, 137.1, 136.9, 132.7, 130.0, 129.6,
127.8, 125.0, 123.2, 121.3, 121.1, 121.1, 117.4, 114.2,
113.3, 67.1, 55.3, 54.6, 29.9, 21.6. HRMS (ESI)
([M+Na]+) Calcd. For [C25H24NaO4S]+: 443.1288, Found:
443.1289.
(3o):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (34.1 mg, 81%
yield). H NMR (600 MHz, CDCl3) δ: 7.72 (d, J = 7.8 Hz,
1
2H), 7.53 (d, J = 7.2 Hz, 1H), 7.29–7.24 (m, 3H), 7.17–
7.16 (m, 1H), 7.08 (d, J = 7.2 Hz, 1H), 7.00 (s, 1H), 6.91–
6.84 (m, 4H), 4.73 (d, J = 10.8 Hz, 1H), 4.01 (d, J = 11.4
Hz, 1H), 3.79 (s, 3H), 3.60 (s, 2H), 3.08 (d, J =8.4 Hz, 1H),
2.44 (s, 3H). 13C NMR (150 MHz, CDCl3) δ: 157.2, 153.6,
144.6, 136.9, 132.5, 129.9, 129.5, 129.3, 128.7, 127.8,
125.2, 124.7, 121.4, 121.2, 120.4, 119.1, 117.2, 110.6, 67.2,
55.4, 54.7, 30.3, 21.6. HRMS (ESI) ([M+Na]+) Calcd. For
[C25H24NaO4S]+: 433.1288, Found: 433.1286.
(E)-4-(3-Fluorobenzylidene)-3-(tosylmethyl)chroman
(E)-4-(2-Fluorobenzylidene)-3-(tosylmethyl)chroman
(3l):
Isolated
by
column
chromatography
(3p):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (33.1 mg, 81% (EtOAc/petroleum ether = 1:20); white solid (31.0 mg, 76%
1
1
yield). H NMR (600 MHz, CDCl3) δ: 7.74 (d, J = 8.4 Hz,
yield). H NMR (600 MHz, CDCl3) δ: 7.71 (d, J = 8.4 Hz,
2H), 7.48 (dd, J1 = 1.2 Hz, J2 = 7.8 Hz, 1H), 7.30 (d, J =
7.8 Hz, 2H), 7.27–7.23 (m, 1H), 7.18 (t, J = 7.5 Hz, 1H),
7.02 (d, J = 7.8 Hz, 1H), 6.95–6.86 (m, 5H), 4.76 (dd, J1 =
1.2 Hz, J2 = 11.4 Hz, 1H), 3.99 (d, J = 10.8 Hz, 1H), 3.74–
2H), 7.50 (dd, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H), 7.28 (d, J =
7.8 Hz, 2H), 7.25–7.17 (m, 3H), 7.06 (td, J1 = 1.2 Hz, J2 =
8.1 Hz, 1H), 7.00 (td, J1 = 1.2 Hz, J2 = 9.6 Hz, 1H), 6.93–
6.88 (m, 3H), 4.76 (dd, J1 = 1.8 Hz, J2 = 11.4 Hz, 1H), 4.02
3.73 (m, 1H), 3.62–3.58 (m, 1H), 3.04 (d, J = 14.4 Hz, 1H), (d, J = 11.4 Hz, 1H), 3.59–3.53 (m, 2H), 3.06 (d, J = 13.2
2.43 (s, 3H). 13C NMR (150 MHz, CDCl3) δ: 162.7 (d, J =
244.8 Hz), 153.7, 144.8, 137.9 (d, J = 7.7 Hz), 136.5,
Hz, 1H), 2.42 (s, 3H). 13C NMR (150 MHz, CDCl3) δ:
160.1 (d, J = 245.9 Hz), 153.7, 144.6, 136.6, 134.7, 130.1
7
This article is protected by copyright. All rights reserved.

10.1002/adsc.202000846
Advanced Synthesis & Catalysis
(d, J = 2.3 Hz), 129.9, 129.8, 129.0 (d, J = 8.3 Hz), 127.7,
125.1, 124.0 (d, J = 3.3 Hz), 123.5 (d, J = 14.1 Hz), 121.2,
120.7, 117.3, 115.6 (t, J = 2.0 Hz), 115.4, 67.1, 54.4, 30.2,
128.9, 128.6, 127.8, 127.5, 124.3, 122.0 (d, J = 7.5 Hz),
118.5 (d, J = 8.3 Hz), 116.5 (d, J = 23.7 Hz), 110.5 (d, J =
23.9 Hz), 67.1, 54.4, 29.6, 21.6. 19F NMR (377 MHz,
21.5. 19F NMR (565 MHz, CDCl3) δ: -114.00. HRMS (ESI) CDCl3) δ: -122.32. HRMS (ESI) ([M+Na]+) Calcd. For
([M+Na]+) Calcd. For [C24H21FNaO4S]+: 431.1088, Found:
431.1087.
[C24H21FNaO4S]+: 431.1088, Found: 431.1088.
(E)-4-Benzylidene-6-chloro-3-(tosylmethyl)chroman
(3u):
Isolated
by
column
chromatography
(E)-4-(2-Chlorobenzylidene)-3-(tosylmethyl)chroman
(3q):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (34.2 mg, 80%
yield). H NMR (600 MHz, CDCl3) δ: 7.77 (d, J = 7.2 Hz,
2H), 7.33–7.29 (m, 5H), 7.27–7.23 (m, 3H), 7.05 (s, 1H),
7.03–7.02 (m, 1H), 6.90 (s, 1H), 4.77 (d, J = 10.8 Hz, 1H),
3.97 (d, J = 11.4 Hz, 1H), 3.81 (d, J = 10.8 Hz, 1H), 3.55 (t,
1
(EtOAc/petroleum ether = 1:20); white solid (33.2 mg,
78% yield). 1H NMR (400 MHz, CDCl3) δ: 7.67 (d, J = 8.0
Hz, 2H), 7.56 (dd, J1 = 1.2 Hz, J2 = 8.0 Hz, 1H), 7.35 (d, J
= 7.6 Hz, 1H), 7.26–7.25 (m, 2H), 7.23–7.16 (m, 4H),
6.96–6.89 (m, 3H), 4.73 (dd, J1 = 1.6 Hz, J2 = 11.2 Hz, 1H), J = 12.6, 1H), 3.08 (d, J = 14.4 Hz, 1H), 2.45 (s, 3H). 13C
4.04 (d, J = 11.2 Hz, 1H), 3.61–3.55 (m, 1H), 3.46 (dd, J1
= 1.6 Hz, J2 = 10.8 Hz, 1H), 3.00 (d, J = 14.0 Hz, 1H),
2.42 (s, 3H). 13C NMR (100 MHz, CDCl3) δ: 153.8, 144.6,
136.4, 134.2, 134.0, 133.9, 130.1, 129.9, 129.5, 128.5,
127.7, 126.7, 125.1, 121.3, 120.4, 121.2, 117.4, 67.1, 54.6,
30.1, 21.6. HRMS (ESI) ([M+Na]+) Calcd. For
[C24H21ClNaO3S]+: 447.0792, Found: 447.0792.
NMR (150 MHz, CDCl3) δ: 154.1, 144.9, 136.7, 135.4,
131.5, 130.0, 128.8, 128.6, 127.8, 127.4, 126.2, 124.5,
123.7, 122.5, 120.3, 120.3, 67.2, 54.4, 29.6, 21.6. HRMS
(ESI) ([M+Na]+) Calcd. For [C24H21ClNaO3S]+: 447.0792,
Found: 447.0790.
(E)-4-Benzylidene-6-bromo-3-(tosylmethyl)chroman
(3v):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (39.1 mg, 83%
yield). H NMR (600 MHz, CDCl3) δ: 7.76 (d, J = 7.8 Hz,
(E)-4-(Naphthalen-2-ylmethylene)-3-(tosylmethyl)chro
man (3r): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (28.6 mg,
1
2H), 7.57 (s, 1H), 7.33–7.23 (m, 8H), 6.88 (s, 1H), 6.77 (d,
J = 9.0 Hz, 1H), 4.77 (d, J = 11.4 Hz, 1H), 3.96 (d, J =
11.4 Hz, 1H), 3.80 (d, J = 10.8 Hz, 1H), 3.55 (t, J = 12.6
Hz, 1H), 3.09 (d, J = 14.4 Hz, 1H), 2.45 (s, 3H). 13C NMR
(150 MHz, CDCl3) δ: 152.6, 144.9, 136.7, 135.2, 132.1,
131.2, 130.0, 128.8, 128.6, 127.8, 127.5, 124.5, 123.1,
119.1, 113.6, 67.2, 54.3, 29.5, 21.6. HRMS (ESI)
([M+Na]+) Calcd. For [C24H21BrNaO3S]+: 491.0287,
Found: 491.0289.
1
65% yield). H NMR (400 MHz, CDCl3) δ: 7.96–7.94 (m,
2H), 7.82–7.74 (m, 4H), 7.57–7.47 (m, 3H), 7.36 (dd, J1 =
1.2 Hz, J2 = 8.4 Hz, 1H), 7.23–7.17 (m, 3H), 7.08 (s, 1H),
6.96–6.89 (m, 2H), 4.73-4.71 (m, 1H), 4.03–4.00 (m, 2H),
3.71–3.64 (m, 1H), 3.18 (d, J = 14.4 Hz, 1H), 2.37 (s, 3H).
13C NMR (100 MHz, CDCl3) δ: 153.8, 144.8, 136.9, 133.5,
133.1, 132.8, 132.4, 129.9, 129.6, 128.4, 128.1, 127.9,
127.7, 127.4, 127.1, 126.4, 126.3, 125.0, 123.1, 121.3,
121.2, 117.4, 67.2, 54.6, 29.9, 21.6. HRMS (ESI)
([M+Na]+) Calcd. For [C28H24NaO3S]+: 463.1338, Found:
463.1338.
(E)-4-Benzylidene-7-bromo-3-(tosylmethyl)chroman
(3w):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (39.0 mg, 83%
1
yield). H NMR (600 MHz, CDCl3) δ: 7.76 (d, J = 7.8 Hz,
(E)-4-Benzylidene-6-methyl-3-(tosylmethyl)chroman
(3s):
Isolated
by
column
chromatography
2H), 7.43 (s, 1H), 7.33–7.23 (m, 7H), 7.11 (d, J = 8.4 Hz,
1H), 6.88 (s, 1H), 6.82 (d, J = 9.0 Hz, 1H), 4.77 (d, J =
11.4 Hz, 1H), 3.96 (d, J = 11.4 Hz, 1H), 3.79 (d, J = 10.8
Hz, 1H), 3.56 (t, J = 12.6 Hz, 1H), 3.09 (d, J = 14.4 Hz,
1H), 2.45 (s, 3H). 13C NMR (150 MHz, CDCl3) δ: 152.1,
144.9, 136.7, 135.2, 131.3, 130.0, 129.3, 128.8, 128.6,
127.8, 127.5, 126.3, 124.5, 124.4, 122.6, 118.7, 67.2, 54.3,
29.5, 21.6. HRMS (ESI) ([M+Na]+) Calcd. For
[C24H21BrNaO3S]+: 491.0287, Found: 491.0286.
(EtOAc/petroleum ether = 1:20); white solid (30.1 mg,
74% yield). 1H NMR (400 MHz, CDCl3) δ: 7.76 (d, J = 8.0
Hz, 2H), 7.32–7.23 (m, 8H), 6.99 (dd, J1 = 1.6 Hz, J2 = 8.4
Hz, 1H), 6.91 (s, 1H), 6.78 (d, J = 8.4 Hz, 1H), 4.72 (dd, J1
= 1.6 Hz, J2 = 11.2 Hz, 1H), 3.96 (d, J = 11.2 Hz, 1H),
3.78 dd, J1 = 2.0 Hz, J2 = 11.2 Hz, 1H), 3.65-3.59 (m, 1H),
3.09 (d, J = 14.0 Hz, 1H), 2.44 (s, 3H), 2.28 (s, 3H). 13C
NMR (100 MHz, CDCl3) δ: 151.6, 144.7, 136.8, 135.8,
132.6, 130.4, 130.4, 130.0, 128.8, 128.5, 127.8, 127.1,
125.0, 122.9, 120.7, 117.1, 67.0, 54.5, 29.8, 21.6, 20.6.
HRMS (ESI) ([M+Na]+) Calcd. For [C24H24NaO3S]+:
427.1338, Found: 427.1338.
(E)-4-(Thiophen-2-ylmethylene)-3-(tosylmethyl)chroma
n
(3x):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (26.6 mg, 67%
1
yield). H NMR (600 MHz, CDCl3) δ: 7.83 (d, J = 7.2 Hz,
2H), 7.50 (d, J = 7.2 Hz, 1H), 7.34 (d, J = 7.2 Hz, 2H),
7.28 (s, 1H), 7.16–7.15 (m, 1H), 7.13 (s, 1H), 7.07 (s, 1H),
7.03–7.03 (m, 1H), 6.91–6.90 (m, 2H), 4.95 (d, J = 11.4
Hz, 1H), 4.05 (t, J = 12.0 Hz, 2H), 3.56 (t, J = 12.9 Hz,
1H), 3.05 (d, J = 14.4 Hz, 1H), 2.44 (s, 3H). 13C NMR
(150 MHz, CDCl3) δ: 153.9, 144.8, 138.9, 137.1, 129.9,
129.7, 129.4, 128.1, 127.9, 127.7, 126.2, 124.3, 121.3,
120.7, 117.7, 115.2, 66.4, 53.9, 30.6, 21.5. HRMS (ESI)
([M+Na]+) Calcd. For [C22H20NaO3S2]+: 419.0746, Found:
419.0746.
(E)-4-Benzylidene-6-fluoro-3-(tosylmethyl)chroman (3t):
Isolated by column chromatography (EtOAc/petroleum
1
ether = 1:20); white solid (32.4 mg, 79% yield). H NMR
(400 MHz, CDCl3) δ: 7.77 (d, J = 8.4 Hz, 2H), 7.34–7.23
(m, 7H), 7.17 (dd, J1 = 2.8 Hz, J2 = 9.6 Hz, 1H), 6.91–6.82
(m, 3H), 4.76 (dd, J1 = 1.6 Hz, J2 = 11.2 Hz, 1H), 3.96 (d,
J = 11.2 Hz, 1H), 3.81–3.78 (m, 1H), 3.63–3.57 (m, 1H),
3.09 (d, J = 14.0 Hz, 1H), 2.46 (s, 3H). 13C NMR (100
MHz, CDCl3) δ: 157.4 (d, J = 237.3 Hz), 149.8 (d, J = 1.6
Hz), 144.9, 136.7, 135.3, 131.7 (d, J = 2.0 Hz), 130.0,
8
This article is protected by copyright. All rights reserved.

10.1002/adsc.202000846
Advanced Synthesis & Catalysis
(E)-4-(4-bromobenzylidene)-3-(((4-bromophenyl)sulfon
(E)-4-Benzylidene-3-(((4-chlorophenyl)sulfonyl)methyl)
chroman (3ac): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (34.1 mg, 83%
yl)methyl)chromane
(3y):
Isolated
by column
chromatography (EtOAc/petroleum ether = 1:20); white
solid (30.0 mg, 56% yield). 1H NMR (600 MHz, CDCl3) δ:
7.73 (d, J = 8.4 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 7.48–
7.45 (m, 3H), 7.21 (td, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H), 7.12
(d, J = 8.4 Hz, 2H), 6.94 (td, J1 = 1.2 Hz, J2 = 7.2 Hz, 1H),
6.89 (dd, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H), 6.85 (s, 1H), 4.73
(dd, J1 = 1.8 Hz, J2 = 11.4 Hz, 1H), 4.02 (d, J = 10.8 Hz,
1H), 3.74 (d, J1 = 1.8 Hz, J2 = 10.8 Hz, 1H), 3.64–3.60 (m,
1H), 3.05 (d, J = 14.4 Hz, 1H). 13C NMR (150 MHz,
CDCl3) δ: 153.7, 138.6, 134.6, 133.0, 132.8, 131.8, 130.4,
129.9, 129.4, 125.0, 122.1, 121.5, 121.5, 120.7, 117.5, 67.1,
54.5, 29.7. HRMS (ESI) ([M+Na]+) Calcd. For
[C23H18Br2NaO3S]+: 554.9236, Found: 554.9238.
1
yield). H NMR (600 MHz, CDCl3) δ: 7.77 (d, J = 8.4 Hz,
2H), 7.49–7.45 (m, 3H), 7.31–7.27 (m, 3H), 7.20–7.17 (m,
3H), 6.93–6.88 (m, 3H), 4.76 (d, J = 11.4 Hz, 1H), 4.01 (d,
J = 11.4 Hz, 1H), 3.76 (d, J = 11.4 Hz, 1H), 3.62 (t, J =
12.6 Hz, 1H ), 3.08 (d, J = 14.4 Hz, 1H). 13C NMR (150
MHz, CDCl3) δ: 153.6, 140.5, 138.0, 135.7, 132.2, 129.7,
129.6, 129.3, 128.7, 128.6, 127.3, 124.9, 123.3, 121.3,
120.9, 117.4, 67.0, 54.5, 29.8. HRMS (ESI) ([M+Na]+)
Calcd. For [C23H19ClNaO3S]+: 433.0636, Found: 433.0639.
(E)-4-Benzylidene-3-(((4-bromophenyl)sulfonyl)methyl)
chroman (3ad): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (36.6 mg, 80%
1
yield). H NMR (600 MHz, CDCl3) δ: 7.70 (d, J = 7.8 Hz,
(E)-4-Benzylidene-3-methyl-3-(tosylmethyl)chromane
(3z):
Isolated
by
column
chromatography
2H), 7.63 (d, J = 7.8 Hz, 2H), 7.49 (d, J = 7.8 Hz, 1H),
(EtOAc/petroleum ether = 1:20); white solid (20.8 mg, 51% 7.31–7.27 (m, 3H), 7.20–7.17 (m, 3H), 6.94–6.88 (m, 3H),
1
yield). H NMR (600 MHz, CDCl3) δ: 7.61 (d, J = 8.4 Hz,
2H), 7.23–7.17 (m, 7H), 7.01 (td, J1 = 1.8 Hz, J2 = 7.2 Hz,
1H), 6.74 (dd, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H), 6.51 (dd, J1 =
4.76 (d, J = 11.4 Hz, 1H), 4.01 (d, J = 11.4 Hz, 1H), 3.76
(d, J = 10.8 Hz, 1H), 3.64–3.60 (m, 1H), 3.07 (d, J = 14.4
Hz, 1H). 13C NMR (150 MHz, CDCl3) δ: 153.6, 138.6,
1.2 Hz, J2 = 7.8 Hz, 1H), 6.46 (s, 1H), 6.35 (td, J1 = 0.6 Hz, 135.7, 132.7, 132.2, 129.6, 129.3, 129.2, 128.7, 128.6,
J2 = 7.8 Hz, 1H), 4.30 (d, J = 11.4 Hz, 1H), 3.92 (d, J =
11.4 Hz, 1H), 3.43 (d, J = 15.0 Hz, 1H), 3.23 (d, J = 15.0
Hz, 1H), 2.35 (s, 3H), 1.60 (s, 3H). 13C NMR (150 MHz,
CDCl3) δ: 153.4, 144.2, 137.7, 137.4, 135.1, 130.2, 129.5,
129.4, 128.9, 128.3, 127.8, 126.9, 123.8, 119.5, 118.0,
127.3, 124.9, 123.3, 121.4, 120.9, 117.4, 67.0, 54.5, 29.8.
HRMS (ESI) ([M+Na]+) Calcd. For [C23H19BrNaO3S]+:
477.0130, Found: 477.1028.
(E)-4-Benzylidene-3-(((4-iodophenyl)sulfonyl)methyl)ch
116.3, 74.9, 59.6, 36.5, 21.5, 19.7. HRMS (ESI) ([M+Na]+) roman (3ae): Isolated by column chromatography
Calcd. For [C25H24NaO3S]+: 427.1338, Found: 427.1339.
(EtOAc/petroleum ether = 1:20); white solid (39.2 mg, 78%
1
yield). H NMR (600 MHz, CDCl3) δ: 7.85 (d, J = 8.4 Hz,
2H), 7.54 (d, J = 8.4 Hz, 2H), 7.49 (d, J = 7.8 Hz, 1H),
7.30–7.29 (m, 3H), 7.20–7.18 (m, 3H), 6.94–6.88 (m, 3H),
4.76 (d, J = 11.4 Hz, 1H), 4.01 (d, J = 11.4 Hz, 1H), 3.75
(d, J = 10.8 Hz, 1H), 3.63–3.59 (m, 1H), 3.07 (d, J = 14.4
Hz, 1H). 13C NMR (150 MHz, CDCl3) δ: 153.6, 139.2,
138.6, 135.7, 132.2, 129.6, 129.1, 128.7, 128.6, 127.4,
124.9, 123.3, 121.4, 120.9, 117.4, 101.9, 67.0, 54.5, 29.8.
HRMS (ESI) ([M+Na]+) Calcd. For [C23H19INaO3S]+:
524.9992, Found: 524.9995.
(E)-4-Benzylidene-3-((phenylsulfonyl)methyl)chroman
(3aa):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (22.4 mg,
1
59% yield). H NMR (400 MHz, CDCl3) δ: 7.91–7.89 (m,
2H), 7.65 (t, J = 7.4 Hz, 1H), 7.55–7.48 (m, 3H), 7.33–
7.29 (m, 2H), 7.26–7.23 (m, 3H), 7.19 (td, J1 = 1.2 Hz, J2 =
8.4 Hz, 1H), 6.93–6.88 (m, 3H), 4.77 (dd, J1 = 2.0 Hz, J2 =
11.2 Hz, 1H), 4.00 (d, J = 11.2 Hz, 1H), 3.86 (dd, J1 = 2.0
Hz, J2 = 11.2 Hz, 1H), 3.67–3.61 (m, 1H), 3.12 (d, J = 14.0
Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 153.6, 139.8,
135.7, 133.8, 132.3, 129.5, 129.4, 128.8, 128.6, 127.3,
125.0, 123.3, 121.3, 121.1, 117.3, 67.1, 54.5, 29.7. HRMS
(ESI) ([M+Na]+) Calcd. For [C23H20NaO3S]+: 339.1025,
Found: 339.1023.
(E)-4-Benzylidene-3-((m-tolylsulfonyl)methyl)chroman
(3af):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (24.3 mg,
62% yield). 1H NMR (400 MHz, CDCl3) δ: 7.71 (d, J = 7.6
Hz, 2H), 7.50-7.40 (m, 3H), 7.33–7.24 (m, 5H), 7.19 (td, J1
= 1.2 Hz, J2 = 8.4 Hz, 1H), 6.94–6.88 (m, 3H), 4.79 (dd, J1
= 1.6 Hz, J2 = 11.2 Hz, 1H), 4.01 (d, J = 11.2 Hz, 1H),
3.86 (dd, J1 = 1.6 Hz, J2 = 11.2 Hz, 1H), 3.67–3.60 (m, 1H),
3.12 (d, J = 14.4 Hz, 1H), 2.42 (s, 3H). 13C NMR (100
MHz, CDCl3) δ: 153.7, 139.7, 139.7, 135.7, 134.6, 132.4,
129.5, 129.3, 128.9, 128.6, 128.1, 127.3, 125.0, 124.9,
123.2, 121.3, 121.1, 117.3, 67.1, 54.4, 29.7, 21.3. HRMS
(ESI) ([M+Na]+) Calcd. For [C24H22NaO3S]+: 413.1182,
Found: 413.1182.
(E)-4-Benzylidene-3-(((4-fluorophenyl)sulfonyl)methyl)
chroman (3ab): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (23.6 mg,
1
60% yield). H NMR (600 MHz, CDCl3) δ: 7.90–7.88 (m,
2H), 7.50 (dd, J1 = 1.8 Hz, J2 = 8.4 Hz, 1H), 7.33 (t, J = 7.2
Hz, 2H), 7.29–7.24 (m, 3H), 7.21–7.18 (m, 3H), 6.95–6.89
(m, 3H), 4.77 (dd, J1 = 1.8 Hz, J2 = 10.8 Hz, 1H), 4.03 (d,
J = 11.4 Hz, 1H), 3.82 (dd, J1 = 1.8 Hz, J2 = 10.8 Hz, 1H),
3.66-3.62 (m, 1H), 3.10 (d, J = 14.4 Hz, 1H). 13C NMR
(150 MHz, CDCl3) δ: 165.8 (d, J = 255.5 Hz), 153.7, 135.8,
135.7, 132.3, 130.7 (d, J = 9.6 Hz), 129.7, 128.8, 128.7,
127.4, 125.0, 123.4, 121.4, 121.1, 117.4, 116.7 (d, J = 22.8
Hz), 67.1, 54.8, 29.9. 19F NMR (565 MHz, CDCl3) δ:
-103.14. HRMS (ESI) ([M+Na]+) Calcd. For
[C23H19FNaO3S]+: 417.0931, Found: 417.0930.
(E)-4-Benzylidene-3-(((3-chlorophenyl)sulfonyl)methyl)
chroman (3ag): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (32.6 mg, 79%
yield). 1H NMR (600 MHz, CDCl3) δ: 7.87 (s, 1H), 7.75 (d,
J = 7.8 Hz, 1H), 7.60 (d, J = 7.8 Hz, 1H), 7.50–7.44 (m,
9
This article is protected by copyright. All rights reserved.

10.1002/adsc.202000846
Advanced Synthesis & Catalysis
2H), 7.34–7.32 (m, 2H), 7.27–7.24 (m, 3H), 7.19 (t, J = 7.2
Hz, 1H), 6.95–6.89 (m, 3H), 4.77 (d, J = 10.8 Hz, 1H),
J = 11.4 Hz, 1H), 3.84 (d, J = 10.8 Hz, 1H), 3.64 (t, J =
12.6 Hz, 1H), 3.10 (d, J = 14.4 Hz, 1H). 13C NMR (150
4.02 (d, J = 11.4 Hz, 1H), 3.83 (d, J = 10.8 Hz, 1H), 3.63 (t, MHz, CDCl3) δ: 153.6, 142.6, 136.4, 135.7, 133.9, 132.0,
J = 12.6 Hz, 1H), 3.11 (d, J = 14.4 Hz, 1H). 13C NMR (150
MHz, CDCl3) δ: 153.6, 141.4, 135.6, 135.6, 134.0, 132.1,
130.7, 129.6, 128.8, 128.6, 127.9, 127.4, 125.9, 124.9,
123.4, 121.4, 121.0, 117.4, 67.1, 54.5, 29.7. HRMS (ESI)
([M+Na]+) Calcd. For [C23H19ClNaO3S]+: 433.0636, Found:
433.0636.
129.7, 128.7, 128.7, 127.6, 126.2, 124.9, 123.6, 121.5,
120.9, 117.5, 67.2, 54.7, 29.8. HRMS (ESI) ([M+Na]+)
Calcd. For [C23H18Cl2NaO3S]+: 467.0246, Found:
467.0246.
(E)-4-Benzylidene-3-((n-butylsulfonyl)methyl)chroman
(3al):
Isolated
by
column
chromatography
(EtOAc/petroleum ether = 1:20); white solid (16.1 mg, 45%
yield). H NMR (600 MHz, CDCl3) δ: 7.59 (dd, J1 = 1.2
(E)-4-Benzylidene-3-(((3-bromophenyl)sulfonyl)methyl)
chroman (3ah): Isolated by column chromatography
1
(EtOAc/petroleum ether = 1:20); white solid (35.4 mg, 78% Hz, J2 = 7.8 Hz, 1H), 7.43–7.38 (m, 4H), 7.31–7.28 (m,
yield). 1H NMR (600 MHz, CDCl3) δ: 8.03 (s, 1H), 7.81 (d, 1H), 7.23–7.21 (m, 1H), 7.03 (s, 1H), 6.97 (td, J1 = 1.2 Hz,
J = 7.8 Hz, 1H), 7.76 (d, J = 7.8 Hz, 1H), 7.50 (d, J = 7.8
Hz, 1H), 7.40 (t, J = 7.8 Hz, 1H), 7.35–7.33 (m, 2H), 7.29–
7.25 (m, 3H), 7.20 (t, J = 7.5 Hz, 1H), 6.95–6.89 (m, 3H),
4.78 (d, J = 11.4 Hz, 1H), 4.04 (d, J = 11.4 Hz, 1H), 3.85
(d, J = 10.8 Hz, 1H), 3.64 (t, J = 12.3 Hz, 1H), 3.12 (d, J =
J2 = 8.1 Hz, 1H), 6.92 (dd, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H),
4.75 (dd, J1 = 2.4 Hz, J = 11.4 Hz, 1H), 4.06 (d, J = 11.4
Hz, 1H), 3.93 (dd, J1 = 2.4 Hz, J2 = 10.8 Hz, 1H), 3.49–
3.45 (m, 1H), 2.97 (dd, J1 = 1.2 Hz, J2 = 14.4 Hz, 1H),
2.88–2.84 (m, 2H), 1.77–1.72 (m, 2H), 1.43–1.37 (m, 2H),
14.4 Hz, 1H). 13C NMR (150 MHz, CDCl3) δ: 153.6, 141.6, 0.92 (t, J = 7.2 Hz, 3H). 13C NMR (150 MHz, CDCl3) δ:
136.9, 135.7, 132.2, 130.9, 130.7, 129.6, 128.8, 128.7,
127.5, 126.4, 125.0, 123.5, 123.4, 121.4, 121.0, 117.4, 67.1,
54.6, 29.7. HRMS (ESI) ([M+Na]+) Calcd. For
[C23H19BrNaO3S]+: 477.0130, Found: 477.0128.
153.8, 135.9, 132.5, 129.6, 129.0, 128.8, 127.5, 124.9,
123.3, 121.4, 121.1, 117.5, 67.5, 54.1, 51.0, 29.2, 23.8,
21.6, 13.5. HRMS (ESI) ([M+Na]+) Calcd. For
[C21H24NaO3S]+: 379.1338, Found: 379.1339.
(E)-4-Benzylidene-3-(((2-chlorophenyl)sulfonyl)methyl)
chroman (3ai): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (27.9 mg,
(E)-4-Benzylidene-1-tosyl-3-(tosylmethyl)-1,2,3,4-tetrah
ydroquinoline (5a): Isolated by column chromatography
(EtOAc/petroleum ether = 1:15); white solid (43.4 mg, 80%
1
1
68% yield). H NMR (400 MHz, CDCl3) δ: 8.14 (dd, J1 =
yield). H NMR (600 MHz, CDCl3) δ: 7.68–7.66 (m, 3H),
1.6 Hz, J2 = 8.0 Hz, 1H), 7.59–7.51 (m, 3H), 7.45 (td, J1 =
1.2 Hz, J2 = 8.0 Hz, 1H), 7.36 (d, J = 4.4 Hz, 4H),
7.31-7.28 (m, 1H), 7.21 (td, J1 = 1.2 Hz, J2 = 8.4 Hz, 1H),
7.59 (d, J = 8.4 Hz, 2H), 7.33 (dd, J1 = 1.2 Hz, J2 = 7.8 Hz,
1H), 7.32–7.25 (m, 6H), 7.14–7.10 (m, 3H), 7.07–7.06 (m,
2H), 6.54 (s, 1H), 4.16–4.13 (m, 1H), 4.08–4.05 (m, 1H),
6.99–6.91 (m, 3H), 4.78 (dd, J1 = 1.6 Hz, J2 = 11.2 Hz, 1H), 3.97–3.93 (m, 1H), 3.15–3.05 (m, 2H), 2.45 (s, 3H), 2.21
4.05 (d, J = 11.2 Hz, 1H), 3.95–3.82 (m, 2H), 3.55 (d, J =
(s, 3H). 13C NMR (150 MHz, CDCl3) δ: 144.8, 143.9,
13.6 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 153.7, 137.2, 136.7, 136.6, 136.4, 135.5, 133.6, 130.2, 130.0, 129.7,
135.7, 134.7, 132.9, 132.3, 132.0, 131.5, 129.6, 128.9,
128.6, 127.5, 127.4, 125.0, 123.4, 121.3, 121.1, 117.4, 67.4,
52.5, 29.6. HRMS (ESI) ([M+Na]+) Calcd. For
[C23H19ClNaO3S]+: 433.0636, Found: 433.0635.
128.7, 128.6, 127.9, 127.5, 127.4, 127.2, 125.8, 125.5,
123.3, 57.2, 50.0, 31.5, 21.6, 21.3. HRMS (ESI) ([M+Na]+)
Calcd. For [C31H29NNaO4S2]+: 566.1430, Found:
566.1433.
(E)-4-Benzylidene-3-(((2-bromophenyl)sulfonyl)methyl)
chroman (3aj): Isolated by column chromatography
(EtOAc/petroleum ether = 1:20); white solid (28.6 mg,
(E)-4-(4-Chlorobenzylidene)-1-tosyl-3-(tosylmethyl)-1,2
,3,4-tetrahydroquinoline (5b): Isolated by column
chromatography (EtOAc/petroleum ether = 1:15); white
solid (37.5 mg, 65% yield). 1H NMR (400 MHz, CDCl3) δ:
7.66 (dd, J1 = 2.4 Hz, J2 = 8.8 Hz, 3H), 7.61 (d, J = 8.0 Hz,
2H), 7.38–7.32 (m, 3H), 7.26–7.23 (m, 3H), 7.16–7.10 (m,
3H), 7.00 (d, J = 8.0 Hz, 2H), 6.51 (s, 1H), 4.15–4.05 (m,
2H), 3.87 (d, J = 6.4 Hz, 1H), 3.19–3.13 (m, 1H), 2.99 (dd,
1
64% yield). H NMR (400 MHz, CDCl3) δ: 8.16 (dd, J1 =
1.6 Hz, J2 = 8.0 Hz, 1H), 7.73 (dd, J1 = 1.6 Hz, J2 = 7.2 Hz,
1H), 7.52–7.43 (m, 3H), 7.38–7.32 (m, 4H), 7.28–7.26 (m,
1H), 7.20 (td, J1 = 1.6 Hz, J2 = 8.4 Hz, 1H), 6.97–6.89 (m,
3H), 4.78 (dd, J1 = 2.0 Hz, J2 = 11.6 Hz, 1H), 4.04 (d, J =
11.2 Hz, 1H), 3.94–3.81 (m, 2H), 3.57 (d, J = 14.0 Hz, 1H). J1 = 2.4 Hz, J2 = 14.4 Hz, 1H), 2.47 (s, 3H), 2.26 (s, 3H).
13C NMR (100 MHz, CDCl3) δ: 153.7, 138.9, 135.7, 135.6,
134.8, 132.3, 131.8, 129.6, 129.0, 128.6, 128.1, 127.4,
125.1, 123.4, 121.3, 121.1, 121.1, 117.4, 67.4, 52.1, 29.6.
HRMS (ESI) ([M+Na]+) Calcd. For [C23H19BrNaO3S]+:
477.0130, Found: 477.0130.
13C NMR (100 MHz, CDCl3) δ: 145.0, 144.0, 136.6, 136.3,
134.6, 134.0, 133.3, 130.0, 129.9, 129.7, 129.5, 128.9,
128.7, 127.9, 127.2, 126.0, 125.8, 125.4, 123.0, 57.1, 49.9,
31.4, 21.6, 21.4. HRMS (ESI) ([M+Na]+) Calcd. For
[C31H28ClNNaO4S2]+: 600.1040, Found: 600.1041.
(E)-4-Benzylidene-3-(((3,5-dichlorophenyl)sulfonyl)met
hyl)chroman (3ak): Isolated by column chromatography
(E)-4-Benzylidene-7-bromo-1-tosyl-3-(tosylmethyl)-1,2,
3,4-tetrahydroquinoline (5c): Isolated by column
(EtOAc/petroleum ether = 1:20); white solid (28.9 mg, 65% chromatography (EtOAc/petroleum ether = 1:15); white
yield). 1H NMR (600 MHz, CDCl3) δ: 7.73 (s, 2H), 7.59 (s,
1H), 7.50 (d, J = 7.8 Hz, 1H), 7.36 (t, J = 7.2 Hz, 2H),
7.30–7.27 (m, 1H), 7.26–7.25 (m, 2H), 7.21 (t, J = 7.8 Hz,
1H), 6.97–6.90 (m, 3H), 4.78 (d, J = 10.8 Hz, 1H), 4.07 (d,
solid (43.1 mg, 69% yield). 1H NMR (400 MHz, CDCl3) δ:
7.89 (d, J = 1.6 Hz, 1H), 7.68–7.63 (m, 4H), 7.33–7.27 (m,
5H), 7.24–7.20 (m, 2H), 7.17 (d, J = 8.0 Hz, 2H), 7.09 (dd,
J1 = 1.2 Hz, J2 = 6.4 Hz, 2H), 6.57 (s, 1H), 4.20–4.15 (m,
10
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10.1002/adsc.202000846
Advanced Synthesis & Catalysis
1H), 4.01–3.94 (m, 2H), 3.16–3.02 (m, 2H), 2.45 (s, 3H),
2.26 (s, 3H). 13C NMR (100 MHz, CDCl3) δ: 144.9, 144.3,
137.5, 136.4, 136.1, 135.2, 132.9, 130.0, 129.8, 128.7,
128.7, 128.3, 128.2, 127.9, 127.6, 127.6, 127.2, 127.1,
125.4, 121.1, 56.7, 49.8, 31.0, 21.6, 21.4. HRMS (ESI)
([M+Na]+) Calcd. For [C31H28BrNNaO4S2]+: 644.0535,
Found: 644.0534.
1406; b) J.-K. Qiu, B. Jiang, Y.-L. Zhu, W.-J. Hao,
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Chem. Soc. 2015, 137, 8928–8931; c) H.-M. Huang,
D. J. Procter, J. Am. Chem. Soc. 2016, 138, 7770–
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M. Brasholz, Angew. Chem. Int. Ed. 2017, 56, 1402–
1406; e) J. Buendia, Z. Chang, H. Eijsberg, R. Guillot,
A. Frongia, F. Secci, J. Xie, S. Robin, T. Boddaert, D.
J. Aitken, Angew. Chem. Int. Ed. 2018, 57, 6592–
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(E)-4-Benzylidene-3-(((4-bromophenyl)sulfonyl)methyl)
-1-tosyl-1,2,3,4-tetrahydroquinoline (5d): Isolated by
column chromatography (EtOAc/petroleum ether = 1:15);
1
white solid (40.1 mg, 66% yield). H NMR (600 MHz,
CDCl3) δ: 7.68–7.60 (m, 7H), 7.40 (dd, J1 = 1.2 Hz, J2 =
7.8 Hz, 1H), 7.33–7.28 (m, 3H), 7.27–7.25 (m, 1H), 7.17
(d, J = 8.4 Hz, 2H), 7.13 (t, J = 7.2 Hz, 1H), 7.06 (d, J =
6.6 Hz, 2H), 6.63 (s, 1H), 4.17–4.14 (m, 1H), 4.08–4.05 (m,
1H), 3.93–3.92 (m, 1H), 3.21–3.17 (m, 1H), 3.06 (dd, J1 =
3.0 Hz, J2 = 15.0 Hz, 1H), 2.27 (s, 3H). 13C NMR (150
MHz, CDCl3) δ: 144.1, 138.3, 136.7, 136.6, 135.6, 133.5,
132.7, 129.8, 129.5, 129.5, 129.2, 128.8, 128.7, 128.6,
127.6, 127.6, 127.2, 125.8, 125.4, 123.0, 57.0, 49.9, 31.3,
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21.4.
HRMS
(ESI)
([M+Na]+)
Calcd.
For
[C30H26BrNNaO4S2]+: 630.0379, Found: 630.0380.
(E)-4-Benzylidene-3-(((3-chlorophenyl)sulfonyl)methyl)
-1-tosyl-1,2,3,4-tetrahydroquinoline (5e): Isolated by
column chromatography (EtOAc/petroleum ether = 1:15);
1
white solid (32.7 mg, 58% yield). H NMR (600 MHz,
CDCl3) δ: 7.73 (t, J = 1.8 Hz, 1H), 7.69–7.66 (m, 2H),
7.63–7.61 (m, 3H), 7.47 (t, J = 8.4 Hz, 1H), 7.39 (dd, J1 =
1.2 Hz, J2 = 7.8 Hz, 1H), 7.34–7.26 (m, 4H), 7.17–7.12 (m,
3H), 7.06 (d, J = 7.2 Hz, 2H), 6.62 (s, 1H), 4.15–4.08 (m,
2H), 4.00–3.96 (m, 1H), 3.20–3.16 (m, 1H), 3.07 (dd, J1 =
2.4 Hz, J2 = 14.4 Hz, 1H), 2.25 (s, 3H). 13C NMR (150
MHz, CDCl3) δ: 144.1, 141.1, 136.7, 136.6, 135.6, 135.5,
134.0, 133.4, 130.7, 129.8, 129.7, 128.8, 128.7, 128.6,
128.0, 127.7, 127.2, 126.1, 125.8, 125.5, 123.2, 57.0, 50.0,
31.3, 21.4. HRMS (ESI) ([M+Na]+) Calcd. For
[C30H20ClNNaO4S2]+: 586.0884 Found: 563.0882.
Acknowledgements
We gratefully acknowledge the National Natural Science
Foundation of China (21772062, 22071171) for financial
support of this work.
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12
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FULL
PAPER
Visible-Light-Induced
Radical
Cascade
Cyclizations of 1,7-Enynes with Sulfinic Acids:
Direct Access to Sulfonated Chromanes and
Sulfonated
Tetrahydroquinolines
under
Metal-Free Conditions
Adv. Synth. Catal. 2020, Volume, Page – Page
Qi Liu, Yousheng Mei, Lei Wang,* Yongmin Ma,
and Pinhua Li*
13
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