Trifluoromethylselenolation andN-acylation of indoles with [Me4N][SeCF3]

Article abstract of DOI:10.1039/d1ob00842k

An efficient method for oxidative trifluoromethylselenolation/N-acylation of indoles with excess [Me₄N][SeCF₃] in the presence of acyl peroxides and their derivatives is described. The reaction is easy to handle, proceeds smoothly at room temperature under metal-free conditions, and shows advantages such as good functional group tolerance, excellent regioselectivity, and compatibility of a number of substrates, producing 1-acyl and 3-trifluoromethylselanyl substituted indoles in good yields. Acyl peroxides and peroxycarboxylic acid behave as both oxidants and acyl sources in the transformation. This one-pot procedure provides a convenient access to a new class of indole derivatives, representing the first trifluoromethylselanyl bifunctionalization of indoles with the nucleophilic [Me₄N][SeCF₃] reagent.

Full text of DOI:10.1039/d1ob00842k

Organic &
Biomolecular Chemistry
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Trifluoromethylselenolation and N-acylation of
indoles with [Me4N][SeCF3]†
Cite this: Org. Biomol. Chem., 2021,
19, 5368
Kai-Li Tan, Hao-Nan Wang, Tao Dong and Cheng-Pan Zhang
*
An efficient method for oxidative trifluoromethylselenolation/N-acylation of indoles with excess
[Me4N][SeCF3] in the presence of acyl peroxides and their derivatives is described. The reaction is easy to
handle, proceeds smoothly at room temperature under metal-free conditions, and shows advantages
such as good functional group tolerance, excellent regioselectivity, and compatibility of a number of sub-
strates, producing 1-acyl and 3-trifluoromethylselanyl substituted indoles in good yields. Acyl peroxides
and peroxycarboxylic acid behave as both oxidants and acyl sources in the transformation. This one-pot
procedure provides a convenient access to a new class of indole derivatives, representing the first
trifluoromethylselanyl bifunctionalization of indoles with the nucleophilic [Me4N][SeCF3] reagent.
Received 29th April 2021,
Accepted 24th May 2021
DOI: 10.1039/d1ob00842k
rsc.li/obc
molecules can favorably alter their pharmacokinetic and/or
pharmacodynamic properties. Thanks to the usefulness but
Introduction
The unique nature of fluorine arising from a combination of scarcity of SeCF3-containing molecules, developing efficient
small atomic size, very low polarizability, and the highest methods for the installation of SeCF3 groups in diverse
electronegativity has rendered fluorination and fluoroalkyla- organic scaffolds is highly desirable.
tion as powerful tools for modulating the chemical, physical
Nowadays, the direct C-SeCF3 bond formation strategies
and biological properties of organic scaffolds.1 The great have been successfully established with several SeCF3 sources
success of application of fluorine and fluorine-containing via nucleophilic, electrophilic and radical processes.3 These
functionalities in medicinal chemistry and crop protection trifluoromethylselenolation reagents include Hg(SeCF3)2,
has been evidenced by the fact that approximately 20–30% CuSeCF3, AgSeCF3, [Me4N][SeCF3], copper(I) trifluoromethyl-
of pharmaceuticals and 40% of agrichemicals on the market selenolate complexes ([LCuSeCF3]2), Ph3P+CF2CO2−/Se8/CsF
contain at least one fluorine atom.2 Among the known mixture, CF3SeCl, TsSeCF3 and SeCF3-substituted benzothiazo-
fluorinated groups, the SeCF3 moiety has attracted increas- lium salt (BT-SeCF3).7 Tetramethylammonium trifluoromethyl-
ing attention in the last decade because of its valuable selenate ([Me4N][SeCF3]),
a versatile nucleophilic SeCF3
electronic characteristics and useful lipophilicity parameters reagent that was facilely synthesized from TMSCF3, Se8, and
(Hammett constants σp = 0.45, σm = 0.44; Hansch–Leo [Me4N]F, has been profoundly harnessed under Cu, Pd, and Ni
parameter πR
=
1.61).3 Trifluoromethylselenolated com- catalysis by the research groups of Rueping, Goossen,
pounds constitute a new type of chemical entity with Schoenebeck, and Zhang.8 This reagent is thermally stable,
great potential for application in life sciences.4–6 nonvolatile, readily accessible, and easy to handle, circumvent-
Trifluoroselenomethionine, an analogue of trifluoromethio- ing the shortages such as high cost, low atom economy, harsh
nine and selenomethionine, was found to have enhanced reaction conditions, and tedious preparation steps from which
methioninase-induced cytotoxicity toward HCT-116 cells other reagents suffered.7,8 In recent years, the transition-metal-
derived from human colon cancer.4 Recently, studies on free trifluoromethylselenolation of alkynyl(phenyl)iodonium
SeCF3 isosteres of riluzole and pretomanid disclosed that tosylates, organic halides, diaryliodonium triflates, aryldiazo-
chalcogen replacement modulated the physicochemical and nium tetrafluoroborates, α-diazo carbonyls, 1,3-dicarbonyls,
ADME features with no intrinsic liabilities.5 These limited alkyl carboxylic acids, alcohols, and alkenes with
examples indicated that the SeCF3 moieties in bioactive [Me4N][SeCF3] has also been extensively explored, allowing the
facile synthesis of various trifluoromethyl selenoethers.9
Despite the fact that [Me4N][SeCF3] represents one of the most
promising SeCF3 reagents so far,7–9 trifluoromethyl-
School of Chemistry, Chemical Engineering and Life Science, Wuhan University of
Technology, Wuhan 430070, China. E-mail: cpzhang@whut.edu.cn,
selenolation with [Me4N][SeCF3] is much less studied. Thus, it
zhangchengpan1982@hotmail.com
is very necessary to continuously exploit [Me4N][SeCF3] for
†Electronic supplementary information (ESI) available. See DOI: 10.1039/
novel trifluoromethylselenolations.
d1ob00842k
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temperature to 0 °C for a mixture of 1a, [Me4N][SeCF3] (2
equiv.) and BPO (1 equiv.) in CH3CN afforded 36% of 3a and
Results and discussion
In 2019, we reported a metal-free oxidative trifluoromethyl- 53% of 4a (entry 8, Table 1). When this bifunctionalization
selenolation of electron-rich (hetero)arenes with [Me4N][SeCF3] was performed at 40 °C, 60 °C or 80 °C for 16 h, 3a was
in the presence of different oxidants.9c Further investigations obtained in 84%, 62% or 52% yield (entries 9–11, Table 1).
showed that treatment of indole with excess [Me4N][SeCF3] in These results suggested that the reaction temperature signifi-
the presence of acyl peroxide could unexpectedly form an acyl/ cantly impacted the product distribution of 3a and 4a, and
trifluoromethylselanyl bifunctionalized product. Herein, we increasing the reaction temperature from room temperature to
described the details of this cascade trifluoromethyl- 80 °C could gradually decrease the yield of 3a. The reactant
selenolation/acylation process. Intriguingly, the reaction of ratio also had a big effect on the production of 3a. Varying the
indole (1a) with [Me4N][SeCF3] (2 equiv.) and benzoyl peroxide molar ratio of 1a, [Me4N][SeCF3] and BPO from 1 : 2 : 1 to
(BPO, 2a, 1 equiv.) in CH3CN at room temperature under a N2 1 : 2.5 : 1, 1 : 2.5 : 1.5, 1 : 2.5 : 2, 1 : 2 : 2, and 1 : 1 : 1 provided 3a
atmosphere for 16 h gave phenyl(3-((trifluoromethyl)selanyl)- in 86%, 83%, 5%, 6%, and 5% yields together with 4a in 9%,
1H-indol-1-yl)methanone (3a) in 94% yield (93% isolated yield) 15%, 89%, 94% and 94% yields, respectively (entries 12–16,
accompanied by 5% of 3-((trifluoromethyl)selanyl)-1H-indole Table 1). It seemed that the use of excess BPO in this reaction
(4a) (entry 1, Table 1). BPO behaved as both oxidant and acyla- would dramatically frustrate the construction of an acyl/
tion reagent in this reaction. The choice of the solvent had a trifluoromethylselanyl bifunctionalized product, especially
considerable influence on the acyl/trifluoromethylselanyl when its equivalents were close to that of [Me4N][SeCF3].
bifunctionalization of indole. Taking DMF, THF, 1,4-dioxane,
Next, 1a, [Me4N][SeCF3] (2 equiv.), acyl peroxide (1 equiv.),
and dichloromethane instead of CH3CN as a solvent in the CH3CN, room temperature, N2, and 16 h were employed as the
same reaction led to 3a in much lower yields (27–64%) and 4a standard conditions to probe the substrate scope of bifunctio-
in relatively higher yields (10–22%) (entries 2–5, Table 1). nalization (Scheme 1). It was pleasing to find that the reaction
When the reaction was performed in DMSO or toluene, 4a was of 1a with [Me4N][SeCF3] and 4-methylbenzoyl peroxide (2b),
formed as a major product in 63% or 47% yield (entries 6 and 4-fluorobenzoyl peroxide (2c) or 4-bromobenzoyl peroxide
7, Table 1). Decreasing the reaction temperature from room (2d) provided p-tolyl(3-((trifluoromethyl)selanyl)-1H-indol-1-yl)
methanone (3b) in 93% yield, (4-fluorophenyl)(3-((trifluoro-
methyl)selanyl)-1H-indol-1-yl)methanone (3c) in 72% yield,
or (4-bromophenyl)(3-((trifluoromethyl)selanyl)-1H-indol-1-yl)
methanone (3d) in 92% yield. Alkanoyl peroxides were also
suitable oxidants and acylation reagents for one-pot trifluoro-
Table 1 N-Acylation/trifluoromethylselenolation
[Me4N][SeCF3] and BPO
of
indole
with
Entrya
Solvent
Temp. (oC)
Yieldb (3a, %)
Yieldb (4a, %)
1
2
3
4
5
6
7
8
CH3CN
DMF
THF
1,4-Dioxane
DCM
DMSO
Toluene
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
0
40
60
80
r.t.
r.t.
r.t.
r.t.
r.t.
94 (93)
62
64
39
27
28
8
36
84
62
52
86
83
5
5 (5)
10
16
18
22
63
47
53
9
22
48
9
15
89
94
94
9
10
11
12c
13d
14e
15f
16g
6
5
a Reaction conditions: to
a solution of 1a (0.2 mmol) and
[Me4N][SeCF3] (0.4 mmol) in the solvent (1 mL) were added BPO
(0.2 mmol) and the solvent (1 mL). The mixture was reacted at room
temperature under N2 for 16 h. b Yields were determined by HPLC (λ =
249 nm, methanol/water = 90 : 10 (v/v)) using 3a (tR = 7.92 min) and 4a
(tR = 4.58 min) as external standards. Isolated yields are shown in par-
entheses. c 1a : [Me4N][SeCF3] : 2a = 1 : 2.5 : 1. d 1a : [Me4N][SeCF3] : 2a =
1 : 2.5 : 1.5. e 1a : [Me4N][SeCF3] : 2a = 1 : 2.5 : 2. f 1a : [Me4N][SeCF3] : 2a
= 1 : 2 : 2. g 1a : [Me4N][SeCF3] : 2a = 1 : 1 : 1.
Scheme 1 N-Acylation/trifluoromethylselenolation of indole with
[Me4N][SeCF3] in the presence of different acyl peroxides and their
derivatives. Reaction conditions: to a solution of 1a (0.2 mmol) and
[Me4N][SeCF3] (0.4 mmol) in CH3CN (1 mL) were added 2 (0.2 mmol)
and CH3CN (1 mL). The mixture was reacted at room temperature under
N2 for 16 h. Isolated yields. a[Me4N][SeCF3] (0.6 mmol), 2 (0.44 mmol),
room temperature, N2, 8 h.
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methylselenolation/acylation of 1a under the standard con- reacted with [Me4N][SeCF3] (2 equiv.) in CH3CN in the pres-
ditions. Reactions of 1a with excess [Me4N][SeCF3] in the pres- ence of BPO (1 equiv.) at room temperature under N2 for 16 h
ence of 3-phenylpropanoyl peroxide (2e), 4-(thiophen-2-yl)buta- to furnish 3k–n in 53–65% yields. 1H-Pyrrolo[2,3-b]pyridine
noyl peroxide (2f), 3-cyclopentylpropanoyl peroxide (2g), 3,3-di- (1f), an analogue of indole, similarly treated with
methylbutanoyl peroxide (2h), and propionyl peroxide (2i), as [Me4N][SeCF3] (2 equiv.) and BPO (1 equiv.), produced 3o in
representative examples, afforded 3e–i in 71–86% yields. The 45% 19F NMR yield. Since 3o was easily hydrolyzed during
commercially available 3-chlorobenzoperoxoic acid (m-CPBA, workup, a mixture of 3o and a deacylated product (3-((trifluoro-
2j) was confirmed to be applicable in this conversion as well. methyl)selanyl)-1H-pyrrolo[2,3-b]pyridine)
was
eventually
When 1a reacted with [Me4N][SeCF3] (3 equiv.) and m-CPBA obtained. Moreover, reactions of 4-methyl-1H-indole (1g),
(2.2 equiv.) in CH3CN at room temperature under a N2 atmo- 4-chloro-1H-indole (1h), 5-methoxy-1H-indole (1i), 5-iodo-1H-
sphere for 8 h, (3-chlorophenyl)(3-((trifluoromethyl)selanyl)- indole (1j), 1b, 1c, 1d, 6-chloro-1H-indole (1k), and 1e with
1H-indol-1-yl)methanone (3j) was formed in 88% yield (the [Me4N][SeCF3] (3 equiv.) in CH3CN in the presence of m-CPBA
optimization of reaction conditions for m-CPBA is presented in (2.2 equiv.) at room temperature for 8 h provided 3p–x in
the ESI†). Treatment of 1a and [Me4N][SeCF3] with tert-butyl 46–97% yields. Functional groups such as ester, cyano, nitro,
benzoperoxoate (2k) under the same conditions produced 3a halo, and methoxy functionalities on the phenyl rings of
in 10% yield. These results indicated that peroxycarboxylic indoles were well tolerated in this reaction. The electron-donat-
acid was an equally effective reagent for N-acylation/tri- ing groups facilitated the bifunctionalization compared to the
fluoromethylselenolation of indole in comparison with acyl electron-withdrawing ones, which gave higher yields of the
peroxides.
desired products (3p vs. 3q and 3r vs. 3s–v). Additionally, the
Taking BPO or m-CPBA as both oxidant and acyl source, a position of the substituent on indoles had an effect on the
series of indole derivatives with either electron-donating or transformation. Treatment of 4-methyl-1H-indole (1g) with
electron-withdrawing groups on the phenyl rings were readily [Me4N][SeCF3] (3 equiv.) and m-CPBA (2.2 equiv.) under the
converted under the standard conditions to form the corres- standard conditions afforded 3p in 94% yield, while the same
ponding acyl/trifluoromethylselanyl bifunctionalized products reactions of 7-methyl-1H-indole (1l) and 2-methyl-1H-indole
in good yields (Scheme 2). The relatively electron-deficient (1m) with [Me4N][SeCF3]/m-CPBA afforded 3y and 3z in 27%
methyl 1H-indole-5-carboxylate (1b), 1H-indole-5-carbonitrile and 35% yields, respectively. These data implied that the steric
(1c), 5-nitro-1H-indole (1d), and 6-bromo-1H-indole (1e) hindrance around nitrogen atoms of indoles retarded the
trifluoromethylselenolation/N-acylation sequence, leading to
much lower yields of the products even after extension of the
reaction time (e.g., 3z).10
To understand the possible reaction mechanism, several
control experiments were carried out (Scheme 3). Initially, the
reaction of 4a with [Me4N][SeCF3] (2 equiv.) and BPO (1 equiv.)
under the standard conditions provided 3a in 52% yield, while
similar treatment of 4a with [Me4N][SeCF3] (2 equiv.) and
PhCO2H (1 equiv.) afforded 3a in 95% yield (Schemes 3a and
b). Indole (1a) could be directly acylated by BPO (1 equiv.) to
give 56% or 60% of (1H-indol-1-yl)(phenyl)methanone (5a) at
room temperature with or without [Me4N]F (1 equiv.), which
was likely in situ generated from decomposition of
[Me4N][SeCF3] in the reactions (Schemes 3c and d).
Analogously, when 4a reacted with BPO in the presence of
[Me4N]F, 3a was produced in 48% yield (see the ESI†). When
the relatively electron-deficient 5a was treated with
[Me4N][SeCF3] (2 equiv.) and BPO (1 equiv.) under the standard
conditions, no desired product was formed and 98% of 5a was
recovered (Schemes 3e). Combining all these results suggested
that 4a rather than 5a was the key intermediate of the bifunc-
tionalization. Since the oxidation proceeded very fast, the
reduced form of BPO might be the most feasible acyl source in
Scheme 2 N-Acylation/trifluoromethylselenolation of indole deriva- the presence of excess [Me4N][SeCF3]. Nonetheless, the partici-
tives with [Me4N][SeCF3] and BPO or m-CPBA. Reaction conditions: to a
solution of 1 (0.2 mmol) and [Me4N][SeCF3] (0.4 or 0.6 mmol) in CH3CN
(1 mL) were added BPO (0.2 mmol) or m-CPBA (0.44 mmol) and CH3CN
pation of BPO in the acylation steps couldn’t be fully excluded
at this stage. In addition, the reaction of 4a with [Me4N][SeCF3]
(3 equiv.) and m-CPBA (2.2 equiv.) under the optimized con-
ditions furnished 3j in only 9% yield, whereas 4a similarly
(1 mL). The mixture was reacted at room temperature under N2 for 16 h
(BPO) or 8 h (m-CPBA). Isolated yields. aMinor deacylated byproduct
was observed. bThe reaction was performed for 2 days.
mixed with [Me4N][SeCF3] (3 equiv.) in the presence of 3-chloro-
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Scheme 4 A proposed reaction mechanism for bifunctionalization of
indoles.
the standard reaction mixtures (see the ESI†). On the other
hand, the excess [Me4N][SeCF3] (relative to the oxidant) under-
goes α-fluorine elimination to furnish carbonoselenoic di-
fluoride (SevCF2) because of the strong electron-withdrawing
power and leaving tendency of fluorine/fluoride in the free
−SeCF3 anions,9g which is then attacked by the carboxylic acid
anion to yield the reactive benzoic or alkanoic carbonofluori-
doselenoic anhydride (6). Finally, the nitrogen of 4 is acylated
by 6 under the reaction conditions to produce the bifunctiona-
lized product (3). Owing to the rapid production of 4 and con-
sumption of oxidants in the reactions, N-acylation of 4 by acyl
peroxides or other acyl species could be possibly ruled out.
Nevertheless, the exact mechanism of this conversion
remained unclear.
Scheme 3 Control experiments for mechanistic insights.
benzoic acid (2.2 equiv.) provided 3j in 99% yield (Schemes 3f
and g). Different from BPO, m-CPBA was unable to acylate
indole (Scheme 3h). It seemed that the reduced form of
m-CPBA (3-chlorobenzoic acid) was the sole acylation reagent
with [Me4N][SeCF3] in the peroxyacid-mediated reactions.
Additionally, treatment of [Me4N][SeCF3] (3 equiv.)/m-CPBA
(2.2 equiv.) with the relatively electron-poor (3-chlorophenyl)
(1H-indol-1-yl)methanone (5j) under the standard conditions
didn’t form the desired product (3j) either (Scheme 3i). This
observation implied again that the less reactive acylated
species was not an intermediate of the bifunctionalization.
Furthermore, HPLC analysis of a standard reaction mixture of
1a, [Me4N][SeCF3] (2 equiv.) and BPO (1 equiv.) at different
times showed that the trifluoromethylselenolation progressed
very rapidly and meanwhile the singly acylated product was
not detected (see the ESI†). The reaction performed for 5 min
gave an almost quantitative yield of 4a with a trace amount of
3a, and extending the reaction time from 5 min to 12 h gradu-
ally increased the yield of 3a from <1% to 88% with the con-
sumption of 4a. These results demonstrated that the trifluoro-
methylselenolation step occurred prior to the N-acylation step
in bifunctionalization reactions.
Conclusion
In summary, we have developed a convenient method for
trifluoromethylselenolation/N-acylation of indoles with excess
[Me4N][SeCF3] in the presence of acyl peroxides or their deriva-
tives. The reaction proceeded at room temperature under mild
conditions and tolerated
a range of functional groups,
affording the respective 1-acylated and 3-trifluoromethyl-
selanylated products in good yields. Both acyl peroxide and
peroxycarboxylic acid were effective mediators, behaving as not
only oxidants but also acyl sources in the transformations. A
further study showed that the oxidative trifluoromethyl-
selenolation step proceeded promptly, which was prior to the
N-acylation step. This reaction offered an interesting route for
the synthesis of a new family of bifunctionalized indole deriva-
tives via a one-pot procedure.
Experimental section
General information
On the basis of the above results and the previous
literature,9c–g a plausible reaction mechanism was proposed as All reactions were carried out under a nitrogen atmosphere.
shown in Scheme 4. First, expeditious oxidation of Unless otherwise specified, NMR spectra were recorded in
[Me4N][SeCF3] with acyl peroxide or peroxyacid generates elec- CDCl3 or acetone-d6 on a 500 MHz (for 1H), 471 MHz (for 19F),
trophilic SeCF3 species, which rapidly trifluoromethyl- or 126 MHz (for 13C) spectrometer. All chemical shifts were
selenolates indole (1) to form 3-((trifluoromethyl)selanyl)-1H- reported in ppm relative to TMS (0 ppm) for 1H NMR and
indole as a key intermediate (4), and releases the corres- PhOCF3 (−58.0 ppm) for 19F NMR as an internal or external
ponding carboxylic acid byproduct. The formation of car- standard. The HPLC experiments were carried out on a
boxylic acids was verified by their isolation or detection from Wufeng LC-100 II instrument (column: Shodex, C18, 5 μm, 4.6
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× 250 mm), and the yields of the products were determined by 1a : [Me4N][SeCF3] : 2c = 1 : 2 : 1), petroleum ether/dichloro-
using the corresponding pure compounds as the external stan- methane = 4 : 1 (v/v) as eluents for column chromatography.
dards, respectively. Melting points were measured and are M.p.: 95–96 °C. 1H NMR (500 MHz, CDCl3) δ 8.38 (d, J = 7.9
uncorrected. MS experiments were performed on a TOF-Q ESI Hz, 1H), 7.83 (m, 2H), 7.78 (d, J = 7.4 Hz, 1H), 7.67 (s, 1H),
or DART instrument. [Me4N][SeCF3] was prepared according to 7.52–7.46 (m, 2H), 7.29 (t, J = 8.4 Hz, 2H). 19F NMR (471 MHz,
the literature.11 The starting materials (2b–i,12a 5a 12b and CDCl3) δ −36.0 (s, 3F), −104.8 (s, 1F). 13C NMR (126 MHz,
5j 12b) were synthesized according to the literature. Solvents CDCl3) δ 167.0, 165.3 (d, J = 255.1 Hz), 136.2, 135.2, 132.1 (d, J
were dried before use according to the literature.13 Other = 9.1 Hz), 131.9, 129.7 (d, J = 3.3 Hz), 126.1, 124.9, 121.9 (q, J =
reagents in the reactions were all purchased from commercial 335.1 Hz), 120.5, 116.3 (d, J = 22.1 Hz), 116.2, 100.7. IR (KBr):
sources and used without further purification.
3141, 3077, 1696, 1603, 1524, 1509, 1471, 1448, 1433, 1410,
1352, 1334, 1313, 1250, 1239, 1230, 1214, 1160, 1141, 1128,
1102, 1090, 1056, 1014, 966, 878, 886, 851, 826, 810, 773, 756,
736, 709, 693, 631, 607 cm−1. HRMS-ESI (m/z) calcd for
General procedure for trifluoromethylselenolation/N-acylation
of indoles (1) with [Me4N][SeCF3] and an oxidant (2)
Under a nitrogen atmosphere, a Schlenk tube was charged C16H10F4NOSe ([M + H]+): 387.9858; found: 387.9856.
with 1 (0.2 mmol), [Me4N][SeCF3] (0.4 or 0.6 mmol) and
(4-Bromophenyl)(3-((trifluoromethyl)selanyl)-1H-indol-1-yl)
CH3CN (1 mL), followed by addition of 2 (0.2 or 0.44 mmol) methanone (3d). Light yellow solid, 82.2 mg (92%,
and CH3CN (1 mL), with vigorous stirring. The mixture was 1a : [Me4N][SeCF3] : 2d = 1 : 2 : 1), petroleum ether/dichloro-
reacted at room temperature under N2 for 16 h or 8 h and con- methane = 4 : 1 (v/v) as eluents for column chromatography.
1
centrated to dryness under reduced pressure. The residue was M.p.: 136–137 °C. H NMR (500 MHz, CDCl3) δ 8.37 (d, J = 7.9
purified by flash column chromatography on silica gel using a Hz, 1H), 7.76 (d, J = 7.6 Hz, 1H), 7.73 (d, J = 8.3 Hz, 2H),
mixture of petroleum ether and ethyl acetate or dichloro- 7.65–7.63 (m, 3H), 7.50–7.44 (m, 2H). 19F NMR (471 MHz,
methane as eluents to give the trifluoromethylselenolation/ CDCl3) δ −35.9 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 167.1,
N-acylation products (3).
136.1, 135.0, 132.3, 132.3, 131.9, 130.9, 127.7, 126.2, 125.0,
Phenyl(3-((trifluoromethyl)selanyl)-1H-indol-1-yl)methanone 121.9 (q, J = 335.1 Hz), 120.5, 116.3, 101.0 (q, J = 1.5 Hz). IR
(3a). White solid, 68.4 mg (93%, 1a : [Me4N][SeCF3] : 2a = (KBr): 3154, 1681, 1647, 1589, 1531, 1483, 1471, 1446, 1357,
1 : 2 : 1) or 7.4 mg (10%, 1a : [Me4N][SeCF3] : 2k = 1 : 3 : 2.2), pet- 1332, 1313, 1292, 1280, 1244, 1209, 1151, 1137, 1101, 1089,
roleum ether/ethyl acetate = 20 : 1 (v/v) as eluents for column 1072, 1014, 963, 872, 846, 832, 801, 769, 754, 737, 682, 627,
1
chromatography. M.p.: 56–57 °C. H NMR (500 MHz, CDCl3) δ 605 cm−1. HRMS-ESI (m/z) calcd for C16H10BrF3NOSe ([M +
8.40 (d, J = 7.9 Hz, 1H), 7.78–7.75 (m, 3H), 7.69–7.66 (m, 2H), H]+): 447.9058; found: 447.9056.
7.58 (t, J = 7.8 Hz, 2H), 7.50–7.44 (m, 2H). 19F NMR (471 MHz,
3-Phenyl-1-(3-((trifluoromethyl)selanyl)-1H-indol-1-yl)propan-
CDCl3) δ −36.0 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 168.1, 1-one (3e). Light yellow solid, 66.5 mg (84%, 1a :
136.2, 135.5, 133.6, 132.6, 131.9, 129.4, 128.9, 126.1, 124.9, [Me4N][SeCF3] : 2e = 1 : 2 : 1), petroleum ether/ethyl acetate =
122.0 (q, J = 335.1 Hz), 120.4, 116.4, 100.4 (q, J = 1.7 Hz). IR 20 : 1 (v/v) as eluents for column chromatography. M.p.:
1
(KBr): 3364, 3143, 3076, 3060, 3033, 1693, 1639, 1601, 1526, 107–108 °C. H NMR (500 MHz, CDCl3) δ 8.45 (d, J = 8.1 Hz,
1474, 1448, 1352, 1335, 1312, 1247, 1214, 1180, 1156, 1139, 1H), 7.72 (s, 1H), 7.66 (d, J = 7.8 Hz, 1H), 7.41 (t, J = 8.1 Hz,
1107, 1091, 1077, 1055, 1029, 1013, 1002, 964, 943, 927, 870, 1H), 7.37 (t, J = 7.6 Hz, 1H), 7.30 (t, J = 7.3 Hz, 2H), 7.26 (d, J =
848, 821, 796, 762, 737, 723, 708, 693, 658, 595 cm−1
.
7.6 Hz, 2H), 7.22 (t, J = 7.2 Hz, 1H), 3.24 (t, J = 7.4 Hz, 2H), 3.15
HRMS-ESI (m/z) calcd for C16H11F3NOSe ([M + H]+): 369.9952; (t, J = 7.4 Hz, 2H). 19F NMR (471 MHz, CDCl3) δ −35.9 (s, 3F).
found: 369.9967.
13C NMR (126 MHz, CDCl3) δ 170.2, 140.0, 135.8, 132.6, 131.5,
p-Tolyl(3-((trifluoromethyl)selanyl)-1H-indol-1-yl)methanone 128.8, 128.5, 126.7, 126.3, 124.6, 121.9 (q, J = 335.0 Hz), 120.4,
(3b). Light yellow solid, 71.1 mg (93%, 1a : [Me4N][SeCF3] : 2b = 116.7, 101.1 (q, J = 1.5 Hz), 37.7, 30.3. IR (KBr): 3405, 3149,
1 : 2 : 1), petroleum ether/dichloromethane = 3 : 1 (v/v) as 3087, 3060, 3029, 2939, 2920, 1710, 1604, 1531, 1498, 1474,
eluents for column chromatography. M.p.: 142–143 °C. 1H 1445, 1425, 1391, 1350, 1334, 1331, 1320, 1307, 1295, 1218,
NMR (500 MHz, CDCl3) δ 8.38 (d, J = 7.9 Hz, 1H), 7.75 (d, J = 1201, 1155, 1135, 1109, 1089, 1056, 1033, 1016, 979, 922, 906,
7.5 Hz, 1H), 7.70 (s, 1H), 7.68 (d, J = 7.5 Hz, 2H), 7.49–7.42 (m, 798, 789, 786, 761, 750, 736, 717, 696, 672 cm−1. HRMS-ESI
2H), 7.38 (d, J = 7.7 Hz, 2H), 2.49 (s, 3H). 19F NMR (471 MHz, (m/z) calcd for C18H15F3NOSe ([M + H]+): 398.0265; found:
CDCl3) δ −36.1 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 168.2, 398.0279.
143.6, 136.2, 135.7, 131.9, 130.6, 129.7, 129.6, 125.9, 124.7,
4-(Thiophen-2-yl)-1-(3-((trifluoromethyl)selanyl)-1H-indol-
122.0 (q, J = 335.1 Hz), 120.4, 116.3, 100.0 (q, J = 1.5 Hz), 21.7. 1-yl)butan-1-one (3f). White solid, 71.9 mg (86%, 1a :
IR (KBr): 3366, 3150, 3054, 2923, 2853, 1685, 1608, 1527, 1509, [Me4N][SeCF3] : 2f = 1 : 2 : 1), petroleum ether/ethyl acetate =
1468, 1444, 1410, 1350, 1329, 1312, 1293, 1247, 1210, 1182, 20 : 1 (v/v) as eluents for column chromatography. M.p.:
1
1154, 1139, 1100, 1086, 1055, 1016, 961, 863, 849, 828, 811, 104–105 °C. H NMR (500 MHz, CDCl3) δ 8.48 (d, J = 8.1 Hz,
789, 769, 751, 707, 635, 610 cm−1. HRMS-ESI (m/z) calcd for 1H), 7.74 (s, 1H), 7.70 (d, J = 7.7 Hz, 1H), 7.45 (t, J = 7.4 Hz,
C17H13F3NOSe ([M + H]+): 384.0109; found: 384.0115.
1H), 7.41 (t, J = 7.5 Hz, 1H), 7.17 (d, J = 5.1 Hz, 1H), 6.96 (m,
(4-Fluorophenyl)(3-((trifluoromethyl)selanyl)-1H-indol-1-yl) 1H), 6.86 (m, 1H), 3.04 (t, J = 7.3 Hz, 2H), 3.01 (t, J = 7.3 Hz,
methanone (3c). Light yellow solid, 55.3 mg (72%, 2H), 2.26 (m, 2H). 19F NMR (471 MHz, CDCl3) δ −35.9 (s, 3F).
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13C NMR (126 MHz, CDCl3) δ 170.6, 143.6, 135.7, 132.7, 131.5, 1a : [Me4N][SeCF3] : 2j
=
1 : 3 : 2.2), petroleum ether/ethyl
127.0, 126.3, 124.9, 124.6, 123.6, 122.0 (q, J = 335.4 Hz), 120.4, acetate = 20 : 1 (v/v) as eluents for column chromatography. M.
1
116.6, 101.0 (q, J = 1.5 Hz), 34.5, 28.9, 26.2. IR (KBr): 3410, p.: 95–96 °C. H NMR (500 MHz, CDCl3) δ 8.38 (d, J = 8.1 Hz,
3153, 3141, 3111, 2960, 2943, 2930, 2916, 2849, 1713, 1532, 1H), 7.76–7.75 (m, 2H), 7.65–7.62 (m, 3H), 7.52 (t, J = 7.9 Hz,
1473, 1443, 1415, 1407, 1387, 1368, 1307, 1230, 1218, 1199, 1H), 7.50–7.45 (m, 2H). 19F NMR (471 MHz, CDCl3) δ −35.9 (s,
1155, 1143, 1111, 1092, 1077, 1054, 1016, 1003, 971, 954, 921, 3F). 13C NMR (126 MHz, CDCl3) δ 166.6, 136.1, 135.3, 135.2,
903, 878, 845, 838, 765, 751, 736, 707, 671, 655, 600 cm−1
.
134.9, 132.7, 131.9, 130.2, 129.4, 127.3, 126.3, 125.1, 121.9 (q,
HRMS-ESI (m/z) calcd for C17H15F3NOSSe ([M + H]+): 417.9986; J = 335.1 Hz), 120.6, 116.3, 101.2 (q, J = 1.8 Hz). IR (KBr): 3347,
found: 418.0000. 3142, 3077, 2924, 2853, 1680, 1571, 1529, 1471, 1447, 1421,
3-Cyclopentyl-1-(3-((trifluoromethyl)selanyl)-1H-indol-1-yl) 1365, 1359, 1332, 1311, 1293, 1244, 1209, 1141, 1095, 1056,
propan-1-one (3g). Light yellow solid, 58.7 mg (76%, 1016, 1000, 970, 907, 895, 822, 816, 807, 767, 754, 736, 700,
1a : [Me4N][SeCF3] : 2g = 1 : 2 : 1), petroleum ether/ethyl acetate 684, 651, 593 cm−1. HRMS-ESI (m/z) calcd for C16H10ClF3NOSe
= 20 : 1 (v/v) as eluents for column chromatography. M.p.: ([M + H]+): 403.9563; found: 403.9561.
71–72 °C. 1H NMR (500 MHz, CDCl3) δ 8.48 (d, J = 8.1 Hz, 1H),
Methyl 1-benzoyl-3-((trifluoromethyl)selanyl)-1H-indole-
7.83 (s, 1H), 7.71 (d, J = 7.6 Hz, 1H), 7.46–7.39 (m, 2H), 2.98 (t, 5-carboxylate (3k). Light yellow solid, 54.4 mg (64%,
J = 7.4 Hz, 2H), 1.95–1.86 (m, 5H), 1.67 (m, 2H), 1.58 (m, 2H), 1b : [Me4N][SeCF3] : 2a = 1 : 2 : 1), petroleum ether/dichloro-
1.19 (m, 2H). 19F NMR (471 MHz, CDCl3) δ −36.0 (s, 3F). 13C methane = 1 : 1 (v/v) as eluents for column chromatography.
NMR (126 MHz, CDCl3) δ 171.3, 135.8, 132.8, 131.5, 126.2, M.p.: 126–127 °C. 1H NMR (500 MHz, CDCl3) δ 8.45 (s, 1H),
124.5, 122.0 (q, J = 335.2 Hz), 120.3, 116.7, 100.8 (q, J = 1.6 Hz), 8.41 (d, J = 8.7 Hz, 1H), 8.16 (d, J = 8.8 Hz, 1H), 7.78 (d, J = 7.8
39.5, 35.2, 32.6, 30.7, 25.1. IR (KBr): 3419, 3160, 3138, 3123, Hz, 2H), 7.75 (s, 1H), 7.69 (t, J = 7.7 Hz, 1H), 7.59 (t, J = 7.5 Hz,
3106, 3075, 3051, 2946, 2863, 1716, 1632, 1604, 1526, 1474, 2H), 3.99 (s, 3H). 19F NMR (471 MHz, CDCl3) δ −35.9 (s, 3F).
1445, 1417, 1382, 1362, 1331, 1315, 1299, 1223, 1198, 1183, 13C NMR (126 MHz, acetone-d6) δ 168.0, 166.2, 138.8, 137.8,
1157, 1113, 1099, 1056, 1017, 974, 948, 916, 814, 792, 762, 750, 133.2, 132.9, 131.8, 129.6, 128.9, 126.7, 126.6, 122.3 (q, J =
737, 670, 601 cm−1. HRMS-ESI (m/z) calcd for C17H19F3NOSe 334.1 Hz), 121.8, 116.2, 99.7 (q, J = 1.8 Hz), 51.6. IR (KBr):
([M + H]+): 390.0578; found: 390.0583.
3406, 3155, 3061, 3040, 2995, 2947, 2922, 2852, 1714, 1703,
3,3-Dimethyl-1-(3-((trifluoromethyl)selanyl)-1H-indol-1-yl) 1670, 1612, 1601, 1520, 1469, 1449, 1438, 1356, 1336, 1309,
butan-1-one (3h). Light yellow liquid, 51.7 mg (71%, 1282, 1262, 1237, 1211, 1189, 1158, 1136, 1124, 1103, 1093,
1a : [Me4N][SeCF3] : 2h = 1 : 2 : 1), petroleum ether/ethyl acetate 1064, 987, 955, 945, 905, 889, 844, 830, 819, 797, 775, 768, 747,
1
= 20 : 1 (v/v) as eluents for column chromatography. H NMR 725, 699, 667 cm−1. HRMS-ESI (m/z) calcd for C18H13F3NO3Se
(500 MHz, CDCl3) δ 8.55 (d, J = 7.9 Hz, 1H), 7.83 (s, 1H), 7.71 ([M + H]+): 428.0007; found: 428.0013.
(d, J = 7.7 Hz, 1H), 7.46–7.39 (m, 2H), 2.84 (s, 2H), 1.17 (s, 9H).
1-Benzoyl-3-((trifluoromethyl)selanyl)-1H-indole-5-carbo-
19F NMR (471 MHz, CDCl3) δ −36.1 (s, 3F). 13C NMR nitrile (3l). Light yellow solid, 44.9 mg (53%, 1c :
(126 MHz, CDCl3) δ 170.0, 135.9, 133.5, 131.6, 126.2, 124.5, [Me4N][SeCF3] : 2a = 1 : 2 : 1), petroleum ether/dichloromethane
121.9 (q, J = 335.1 Hz), 120.3, 116.9, 100.4 (q, J = 1.6 Hz), 47.9, = 1 : 1 (v/v) as eluents for column chromatography. M.p.:
1
31.8, 29.8. IR (KBr): 3412, 3140, 3066, 3031, 2986, 2961, 2934, 158–160 °C. H NMR (500 MHz, CDCl3) δ 8.49 (d, J = 8.6 Hz,
2913, 2870, 1712, 1655, 1601, 1526, 1473, 1465, 1449, 1406, 1H), 8.09 (s, 1H), 7.81 (s, 1H), 7.78 (d, J = 7.8 Hz, 2H),
1394, 1372, 1361, 1345, 1297, 1253, 1218, 1160, 1130, 1109, 7.74–7.71 (m, 2H), 7.61 (t, J = 7.4 Hz, 2H). 19F NMR (471 MHz,
1089, 1055, 1017, 989, 946, 936, 895, 831, 799, 765, 747, 735, CDCl3) δ −35.8 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 167.8,
676 cm−1. HRMS-ESI (m/z) calcd for C15H17F3NOSe ([M + H]+): 138.1, 137.4, 133.4, 132.5, 132.2, 129.6, 129.2, 129.1, 125.4,
364.0422; found: 364.0432.
120.3 (q, J = 335.3 Hz), 119.1, 117.3, 108.5, 99.9. IR (KBr): 3447,
1-(3-((Trifluoromethyl)selanyl)-1H-indol-1-yl)propan-1-one 3146, 2958, 2923, 2852, 2228, 1698, 1656, 1610, 1601, 1581,
(3i). Light yellow solid, 45.9 mg (72%, 1a : [Me4N][SeCF3] : 2i = 1524, 1460, 1447, 1435, 1349, 1334, 1327, 1309, 1276, 1253,
1 : 2 : 1), petroleum ether/ethyl acetate = 20 : 1 (v/v) as eluents 1212, 1179, 1146, 1131, 1113, 1103, 1089, 1055, 999, 977, 952,
for column chromatography. M.p.: 87–88 °C. 1H NMR 937, 897, 837, 819, 794, 769, 736, 723, 701, 669, 635 cm−1
.
(500 MHz, CDCl3) δ 8.48 (d, J = 8.1 Hz, 1H), 7.83 (s, 1H), 7.71 HRMS-DART (m/z) calcd for C17H13F3N3OSe ([M + NH4]+):
(d, J = 7.7 Hz, 1H), 7.46–7.39 (m, 2H), 3.01 (q, J = 7.3 Hz, 2H), 412.0170; found: 412.0165.
1.38 (t, J = 7.3 Hz, 3H). 19F NMR (471 MHz, CDCl3) δ −36.0 (s,
(5-Nitro-3-((trifluoromethyl)selanyl)-1H-indol-1-yl)(phenyl)
3F). 13C NMR (126 MHz, CDCl3) δ 171.8, 135.8, 132.7, 131.5, methanone (3m). Light yellow solid, 43.5 mg (53%, 1d :
126.2, 124.5, 121.9 (q, J = 335.2 Hz), 120.3, 116.6, 100.9 (q, J = [Me4N][SeCF3] : 2a = 1 : 2 : 1), petroleum ether/dichloromethane
1.5 Hz), 29.3, 8.6. IR (KBr): 3441, 3424, 3163, 3119, 2981, 2938, = 1 : 1 (v/v) as eluents for column chromatography. M.p.:
1
2917, 1731, 1721, 1529, 1471, 1462, 1443, 1371, 1295, 1222, 124–125 °C. H NMR (500 MHz, CDCl3) δ 8.66 (s, 1H), 8.52 (d,
1178, 1159, 1146, 1108, 1077, 1053, 1009, 966, 894, 808, 762, J = 9.1 Hz, 1H), 8.36 (d, J = 9.1 Hz, 1H), 7.86 (s, 1H), 7.80 (d, J =
756, 736, 655, 602 cm−1
.
HRMS-ESI (m/z) calcd for 7.8 Hz, 2H), 7.73 (t, J = 7.5 Hz, 1H), 7.62 (t, J = 7.5 Hz, 2H).
C12H11F3NOSe ([M + H]+): 321.9952; found: 321.9957. 19F NMR (471 MHz, CDCl3) δ −35.8 (s, 3F). 13C NMR
(3-Chlorophenyl)(3-((trifluoromethyl)selanyl)-1H-indol-1-yl) (126 MHz, CDCl3) δ 167.8, 145.3, 139.2, 138.2, 133.5, 132.4,
methanone
(3j).
White
solid,
70.8
mg
(88%, 132.3, 129.6, 129.2, 121.8 (q, J = 334.9 Hz), 121.2, 116.9, 116.9,
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100.8 (q, J = 1.6 Hz). IR (KBr): 3393, 3144, 3098, 3072, 3034, 1i : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro-
2923, 2852, 1706, 1610, 1600, 1582, 1522, 1440, 1366, 1350, methane = 3 : 1 (v/v) as eluents for column chromatography.
1
1332, 1306, 1264, 1247, 1206, 1180, 1143, 1136, 1120, 1102, M.p.: 106–108 °C. H NMR (500 MHz, CDCl3) δ 8.29 (d, J = 9.0
1089, 1075, 974, 938, 908, 899, 840, 825, 798, 777, 757, 735, Hz, 1H), 7.75 (s, 1H), 7.64–7.60 (m, 2H), 7.57 (s, 1H), 7.51 (t, J
720, 696, 666, 641, 605 cm−1. HRMS-ESI (m/z) calcd for = 7.9 Hz, 1H), 7.17 (s, 1H), 7.08 (d, J = 9.0 Hz, 1H), 3.93 (s, 3H).
C16H10F3N2O3Se ([M + H]+): 414.9803; found: 414.9804.
19F NMR (471 MHz, CDCl3) δ −35.9 (s, 3F). 13C NMR
(6-Bromo-3-((trifluoromethyl)selanyl)-1H-indol-1-yl)(phenyl) (126 MHz, CDCl3) δ 166.3, 157.7, 135.5, 135.2, 133.1, 132.6,
methanone (3n). Light yellow solid, 58.3 mg (65%, 130.6, 130.2, 129.4, 127.2, 121.9 (q, J = 335.2 Hz), 117.4, 115.2,
1e : [Me4N][SeCF3] : 2a = 1 : 2 : 1), petroleum ether/dichloro- 102.7, 101.0 (q, J = 1.5 Hz), 55.8. IR (KBr): 3391, 3144, 3056,
methane = 3 : 1 (v/v) as eluents for column chromatography. 2998, 2958, 2919, 2882, 2853, 2834, 1702, 1611, 1587, 1568,
M.p.: 120–121 °C. 1H NMR (500 MHz, CDCl3) δ 8.64 (s, 1H), 1526, 1474, 1444, 1414, 1365, 1334, 1277, 1254, 1211, 1178,
7.76 (d, J = 7.7 Hz, 2H), 7.69 (t, J = 7.7 Hz, 1H), 7.64 (s, 1H), 1156, 1134, 1095, 1033, 977, 946, 924, 908, 836, 819, 806, 775,
7.61–7.56 (m, 4H). 19F NMR (471 MHz, CDCl3) δ −35.9 (s, 3F). 755, 741, 728, 683, 668, 654, 631 cm−1. HRMS-ESI (m/z) calcd
13C NMR (126 MHz, CDCl3) δ 167.9, 136.8, 135.8, 133.0, 132.9, for C17H12ClF3NO2Se ([M + H]+): 433.9668; found: 433.9675.
130.8, 129.4, 129.0, 128.3, 121.9 (q, J = 334.8 Hz), 121.6, 120.0,
(3-Chlorophenyl)(5-iodo-3-((trifluoromethyl)selanyl)-1H-indol-
119.5, 100.2 (q, J = 1.6 Hz). IR (KBr): 3375, 3362, 3145, 3132, 1-yl)methanone (3s). Light yellow solid, 92.1 mg (87%,
3123, 3081, 3066, 3051, 2923, 2852, 1697, 1689, 1632, 1599, 1j : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro-
1525, 1517, 1466, 1447, 1423, 1360, 1348, 1316, 1276, 1238, methane = 4 : 1 (v/v) as eluents for column chromatography.
1
1210, 1182, 1160, 1129, 1117, 1104, 1092, 1028, 999, 960, 931, M.p.: 121–122 °C. H NMR (500 MHz, CDCl3) δ 8.14 (d, J = 8.7
881, 870, 819, 810, 782, 746, 735, 718, 698, 664, 622, 614 cm−1
.
Hz, 1H), 8.08 (s, 1H), 7.77–7.75 (m, 2H), 7.65 (d, J = 7.9 Hz,
HRMS-ESI (m/z) calcd for C16H10BrF3NOSe ([M
+
H]+): 1H), 7.61 (d, J = 7.5 Hz, 1H), 7.59 (s, 1H), 7.53 (t, J = 7.9 Hz,
447.9058; found: 447.9060.
1H). 19F NMR (471 MHz, CDCl3) δ −35.8 (s, 3F). 13C NMR
(3-Chlorophenyl)(4-methyl-3-((trifluoromethyl)selanyl)-1H- (126 MHz, CDCl3) δ 166.4, 135.5, 135.4, 135.4, 134.9, 134.8,
indol-1-yl)methanone (3p). White solid, 75.6 mg (94%, 134.0, 132.9, 130.3, 129.5, 129.4, 127.3, 121.8 (q, J = 335.2 Hz),
1g : [Me4N][SeCF3] : 2j
=
1 : 3 : 2.2), petroleum ether/ethyl 118.1, 99.9 (q, J = 1.6 Hz), 89.4. IR (KBr): 3368, 3151, 3120,
acetate = 20 : 1 (v/v) as eluents for column chromatography. M. 3061, 3033, 2992, 2962, 2924, 2852, 1697, 1600, 1564, 1557,
p.: 118–119 °C. 1H NMR (500 MHz, CDCl3) δ 8.30 (d, J = 8.4 Hz, 1531, 1450, 1437, 1423, 1381, 1350, 1312, 1295, 1263, 1239,
1H), 7.75 (s, 1H), 7.65–7.60 (m, 3H), 7.52 (t, J = 7.7 Hz, 1H), 1220, 1208, 1167, 1146, 1137, 1117, 1094, 1070, 1057, 1030,
7.36 (t, J = 7.7 Hz, 1H), 7.17 (d, J = 7.4 Hz, 1H). 2.84 (s, 3H). 19
F
1022, 1000, 968, 927, 897, 886, 873, 804, 792, 782, 754, 748,
NMR (471 MHz, CDCl3) δ −37.6 (s, 3F). 13C NMR (126 MHz, 736, 729, 706, 683, 668, 653, 630, 603 cm−1. HRMS-ESI (m/z)
CDCl3) δ 166.6, 136.5, 135.3, 135.2, 132.7, 132.0, 130.2, 129.5, calcd for C16H9ClF3INOSe ([M + H]+): 529.8529; found: 529.8532.
128.5, 127.4, 127.2, 126.1, 121.7 (q, J = 334.0 Hz), 114.2, 99.5
Methyl 1-(3-chlorobenzoyl)-3-((trifluoromethyl)selanyl)-1H-
(q, J = 1.5 Hz), 19.4. IR (KBr): 3371, 3154, 2965, 2928, 2853, indole-5-carboxylate (3t). Light yellow solid, 78.8 mg (86%,
1689, 1655, 1633, 1595, 1581, 1571, 1528, 1483, 1466, 1454, 1b : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro-
1421, 1411, 1387, 1355, 1327, 1300, 1274, 1249, 1227, 1187, methane = 1 : : 1 (v/v) as eluents for column chromatography.
1168, 1109, 1019, 985, 970, 949, 916, 900, 866, 811, 783, 752, M.p.: 125–126 °C. 1H NMR (500 MHz, CDCl3) δ 8.45 (s, 1H),
736, 719, 688, 661, 621 cm−1. HRMS-ESI (m/z) calcd for 8.41 (d, J = 8.8 Hz, 1H), 8.17 (d, J = 8.8 Hz, 1H), 7.77 (s, 1H),
C17H12ClF3NOSe ([M + H]+): 417.9719; found: 417.9721.
7.70 (s, 1H), 7.66 (d, J = 8.2 Hz, 1H), 7.64 (d, J = 7.7 Hz, 1H),
(4-Chloro-3-((trifluoromethyl)selanyl)-1H-indol-1-yl)(3-chloro- 7.54 (t, J = 7.8 Hz, 1H), 3.99 (s, 3H). 19F NMR (471 MHz, CDCl3)
phenyl)methanone (3q). Light yellow solid, 66.9 mg (77%, δ −35.8 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 166.8, 166.5,
1h : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro- 138.7, 136.1, 135.4, 134.7, 133.1, 131.9, 130.3, 129.5, 127.5,
methane = 3 : 1 (v/v) as eluents for column chromatography. 127.4, 127.2, 122.7, 121.8 (q, J = 334.5 Hz), 116.2, 101.5 (q, J =
1
M.p.: 125–126 °C. H NMR (500 MHz, CDCl3) δ 8.37 (m, 1H), 1.6 Hz), 52.4. IR (KBr): 3419, 3140, 3112, 3060, 2956, 2926,
7.76 (s, 1H), 7.66 (d, J = 8.0 Hz, 1H), 7.62–7.61 (m, 2H), 7.53 (t, 2850, 1719, 1696, 1613, 1570, 1529, 1468, 1434, 1358, 1337,
J = 7.6 Hz, 1H), 7.39–7.36 (m, 2H). 19F NMR (471 MHz, CDCl3) 1291, 1251, 1228, 1162, 1149, 1134, 1104, 1088, 986, 964, 902,
δ −37.2 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 166.4, 137.4, 880, 827, 806, 777, 765, 750, 737, 714, 683, 654, 639, 607 cm−1
136.2, 135.4, 134.7, 133.0, 130.3, 129.6, 127.4, 127.3, 127.0, HRMS-ESI (m/z) calcd for C18H12ClF3NO3Se ([M
.
+
H]+):
126.8, 126.4, 121.8 (q, J = 334.6 Hz), 115.1, 99.2 (q, J = 1.7 Hz). 461.9618; found: 461.9622.
IR (KBr): 3377, 3146, 3107, 3091, 3068, 3033, 2924, 2852, 1692,
1659, 1650, 1569, 1524, 1474, 1461, 1415, 1352, 1329, 1299, carbonitrile (3u). Light yellow solid, 59.2 mg (69%, 1c :
1265, 1242, 1185, 1169, 1148, 1129, 1094, 1058, 999, 966, 929, [Me4N][SeCF3] : 2j 1 : 3 : 2.2), petroleum ether/dichloro-
916, 901, 845, 809, 783, 752, 743, 736, 710, 685, 658, 600 cm−1
1-(3-Chlorobenzoyl)-3-((trifluoromethyl)selanyl)-1H-indole-5-
=
.
methane = 1 : 1 (v/v) as eluents for column chromatography.
1
HRMS-ESI (m/z) calcd for C16H9Cl2F3NOSe ([M
+
H]+): M.p.: 136–137 °C. H NMR (500 MHz, CDCl3) δ 8.49 (d, J = 8.6
437.9173; found: 437.9182.
Hz, 1H), 8.09 (s, 1H), 7.77 (s, 1H), 7.76 (s, 1H), 7.74 (d, J = 8.7
(3-Chlorophenyl)(5-methoxy-3-((trifluoromethyl)selanyl)-1H- Hz, 1H), 7.69 (d, J = 7.6 Hz, 1H), 7.64 (d, J = 7.6 Hz, 1H), 7.56
indol-1-yl)methanone (3r). Light yellow solid, 84.2 mg (97%, (t, J = 7.8 Hz, 1H). 19F NMR (471 MHz, CDCl3) δ −35.6 (s, 3F).
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13C NMR (126 MHz, CDCl3) δ 165.4, 137.0, 135.9, 134.5, 133.2, 1l : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro-
132.4, 131.2, 129.4, 128.5, 128.3, 126.4, 124.5, 120.7 (q, J = methane = 5 : 1 (v/v) as eluents for column chromatography.
335.1 Hz), 117.9, 116.3, 107.8, 99.6 (q, J = 1.7 Hz). IR (KBr): M.p.: 111–113 °C. 1H NMR (500 MHz, CDCl3) δ 7.95 (s, 1H),
3143, 3074, 2955, 2926, 2855, 2225, 1705, 1610, 1569, 1527, 7.81 (d, J = 7.6 Hz, 1H), 7.69 (d, J = 7.9 Hz, 1H), 7.63 (d, J = 7.8
1460, 1435, 1421, 1344, 1330, 1310, 1279, 1250, 1213, 1167, Hz, 1H), 7.54 (s, 1H), 7.53 (t, J = 7.9 Hz, 1H), 7.39 (t, J = 7.5 Hz,
1140, 1088, 1060, 981, 915, 891, 817, 803, 774, 757, 745, 738, 1H), 7.29 (d, J = 7.3 Hz, 1H), 2.48 (s, 3H). 19F NMR (471 MHz,
720, 655, 635 cm−1. HRMS-ESI (m/z) calcd for C17H9ClF3N2OSe CDCl3) δ −36.0 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 165.6,
([M + H]+): 428.9515; found: 428.9515.
136.2, 135.9, 135.4, 134.7, 133.8, 133.1, 130.6, 130.3, 128.8,
(3-Chlorophenyl)(5-nitro-3-((trifluoromethyl)selanyl)-1H-indol- 128.6, 126.0, 125.1, 121.9 (q, J = 334.9 Hz), 118.4, 100.1 (q, J =
1-yl)methanone (3v). Light yellow solid, 41.2 mg (46%, 1.5 Hz), 21.4. IR (KBr): 3397, 3151, 2961, 2924, 2852, 1706,
1d : [Me4N][SeCF3] : 2j
=
1 : 3 : 2.2), petroleum ether/ethyl 1652, 1616, 1596, 1570, 1534, 1485, 1475, 1449, 1442, 1415,
acetate = 4 : 1 (v/v) as eluents for column chromatography. M. 1401, 1378, 1339, 1309, 1268, 1248, 1216, 1169, 1150, 1124,
1
p.: 113–114 °C. H NMR (500 MHz, CDCl3) δ 8.66 (s, 1H), 8.52 1115, 1096, 1057, 1000, 979, 919, 909, 890, 861, 810, 802, 786,
(d, J = 9.1 Hz, 1H), 8.38 (d, J = 9.1 Hz, 1H), 7.81 (s, 1H), 7.79 (s, 770, 753, 740, 690, 676, 651 cm−1. HRMS-ESI (m/z) calcd for
1H), 7.70 (d, J = 7.9 Hz, 1H), 7.66 (d, J = 7.6 Hz, 1H), 7.57 (t, J = C17H12ClF3NOSe ([M + H]+): 417.9719; found: 417.9725.
7.9 Hz, 1H). 19F NMR (471 MHz, CDCl3) δ −35.6 (s, 3F). 13C
(3-Chlorophenyl)(2-methyl-3-((trifluoromethyl)selanyl)-1H-
NMR (126 MHz, CDCl3) δ 166.4, 145.5, 139.1, 137.6, 135.6, indol-1-yl)methanone (3z). Light yellow solid, 28.8 mg (35%,
134.0, 133.5, 132.3, 130.5, 129.6, 127.5, 121.7 (q, J = 334.8 Hz), 1m : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro-
121.4, 116.9, 101.5 (q, J = 1.7 Hz). IR (KBr): 3142, 3077, 2956, methane = 5 : 1 (v/v) as eluents for column chromatography.
1
2925, 2854, 1709, 1612, 1570, 1522, 1469, 1454, 1439, 1419, M.p.: 82–84 °C. H NMR (500 MHz, CDCl3) δ 7.78 (s, 1H), 7.70
1412, 1365, 1350, 1335, 1306, 1279, 1263, 1244, 1206, 1168, (d, J = 7.9 Hz, 1H), 7.66 (d, J = 8.0 Hz, 1H), 7.60 (d, J = 7.7 Hz,
1144, 1089, 999, 977, 956, 911, 901, 892, 852, 824, 800, 783, 763, 1H), 7.46 (t, J = 7.9 Hz, 1H), 7.30 (t, J = 7.6 Hz, 1H), 7.15 (t, J =
756, 736, 717, 683, 654, 642, 603 cm−1. HRMS-ESI (m/z) calcd 8.1 Hz, 1H), 7.00 (d, J = 8.3 Hz, 1H), 2.65 (s, 3H). 19F NMR
for C16H9ClF3N2O3Se ([M + H]+): 448.9414; found: 448.9424.
(471 MHz, CDCl3) δ −35.9 (s, 3F). 13C NMR (126 MHz, CDCl3) δ
(6-Chloro-3-((trifluoromethyl)selanyl)-1H-indol-1-yl)(3-chloro- 168.1, 144.9, 136.4, 136.2, 135.4, 133.7, 131.3, 130.3, 129.9,
phenyl)methanone (3w). Light yellow liquid, 66.9 mg (77%, 128.1, 124.3, 123.7, 122.4 (q, J = 336.9 Hz), 120.2, 113.9, 101.3
1k : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro- (q, J = 1.5 Hz), 14.9. IR (KBr): 3440, 3361, 3060, 2924, 2851,
methane = 3 : 1 (v/v) as eluents for column chromatography. 1689, 1595, 1570, 1561, 1474, 1450, 1435, 1381, 1353, 1310,
1H NMR (500 MHz, CDCl3) δ 8.47 (s, 1H), 7.76 (s, 1H), 7.66 (d, 1293, 1274, 1250, 1217, 1165, 1145, 1115, 1089, 1055, 1031,
J = 8.2 Hz, 2H), 7.62 (d, J = 7.5 Hz, 1H), 7.60 (s, 1H), 7.53 (t, J = 970, 938, 922, 903, 884, 852, 799, 789, 754, 745, 737, 681, 666,
7.8 Hz, 1H), 7.44 (d, J = 8.4 Hz, 1H). 19F NMR (471 MHz, 650, 632, 612 cm−1
.
HRMS-DART (m/z) calcd for
CDCl3) δ −35.8 (s, 3F). 13C NMR (126 MHz, CDCl3) δ 166.4, C17H12ClF3NOSe ([M + H]+): 417.9719; found: 417.9711.
136.4, 135.4, 135.3, 134.7, 132.9, 132.5, 130.4, 130.3, 129.4,
127.3, 125.8, 121.8 (q, J = 334.9 Hz), 121.4, 116.7, 100.9. IR
(KBr): 3434, 3145, 3109, 3058, 2924, 2854, 1747, 1705, 1651,
1632, 1603, 1573, 1526, 1475, 1455, 1427, 1415, 1345, 1316,
Author contributions
C.-P.Z. conceptualized the research. K.-L.T., H.-N.W. and T.D.
collected the data. K.-L.T. and C.-P.Z. analyzed the data and
wrote the manuscript.
1275, 1237, 1211, 1167, 1151, 1121, 1097, 1065, 1060, 965, 901,
875, 816, 794, 774, 748, 737, 720, 632 cm−1. HRMS-ESI (m/z)
calcd for C16H9Cl2F3NOSe ([M + H]+): 437.9173; found: 437.9179.
(6-Bromo-3-((trifluoromethyl)selanyl)-1H-indol-1-yl)(3-chloro-
phenyl)methanone (3x). Light yellow solid, 81.5 mg (85%,
1e : [Me4N][SeCF3] : 2j = 1 : 3 : 2.2), petroleum ether/dichloro-
Conflicts of interest
methane = 3 : 1 (v/v) as eluents for column chromatography.
The authors declare no conflict of interest.
1
M.p.: 66–68 °C. H NMR (500 MHz, CDCl3) δ 8.64 (s, 1H), 7.75
(s, 1H), 7.66 (d, J = 7.9 Hz, 1H), 7.62–7.57 (m, 4H), 7.54 (t, J =
7.9 Hz, 1H). 19F NMR (471 MHz, CDCl3) δ −35.8 (s, 3F). 13C
Acknowledgements
NMR (126 MHz, CDCl3) δ 166.4, 136.7, 135.4, 135.2, 134.7,
132.9, 130.8, 130.3, 129.4, 128.5, 127.3, 121.8 (q, J = 334.4 Hz),
121.7, 120.3, 119.5, 100.9 (q, J = 1.6 Hz). IR (KBr): 3138, 3124,
Talent” Program of Hubei Province (China) for financial
3078, 3064, 2924, 2852, 1694, 1571, 1521, 1472, 1451, 1421,
We thank Wuhan University of Technology and the “Hundred
support.
1353, 1317, 1275, 1235, 1235, 1207, 1161, 1131, 1117, 1096,
964, 893, 871, 820, 791, 771, 758, 749, 735, 707, 683, 655,
626 cm−1
. HRMS-ESI (m/z) calcd for C16H9BrClF3NOSe
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