Large Cu i 8 chalcogenone cubic cages with non-interacting counter ions

Article abstract of DOI:10.1039/c7dt03796a

Two mega size copper(i) cubic cages, [{Cu(Bptp)_1.5}₈(PF₆^-)](PF₆^-)₇ (1) and [{Cu(Bpsp)_1.5}₈(PF₆^-)](PF₆^-)₇ (2), supported by imidazole-2-chalcogenone ligands (Bptp = 2,6-bis(1-isopropylimidazole-2-thione)pyridine and Bpsp = 2,6-bis(1-isopropylimidazole-2-selone)pyridine) have been synthesized and characterized. The formation of ionic salts 1 and 2 was confirmed by FT-IR, multinuclear (¹H, ¹³C, ³¹P and ¹⁹F) NMR, UV-vis, TGA, CHN analysis, BET analysis, single crystal X-ray diffraction and powder X-ray diffraction techniques. To the best of our knowledge, these are the first examples of a octanuclear copper(i) cluster in a perfect cubic architecture with a copper-copper distance of 8.413 ? or 8.593 ?. Interestingly, these anion-centered CuI8 cubic arrangements are not supported by cubic centered ions or face centered molecules. The formation of cationic cubic cages was accompanied by the association of twelve ligands (Bptp or Bpsp) with eight trigonal planar [CuSe₃] vertices. The cationic charge of cubic cages was satisfied by eight PF₆^- counter anions, in which one of the PF₆^- anions occupies the centre of the Cu₈ cube without any interaction. The copper(i) cubic cages are found to be highly active catalysts in click chemistry as well as hydroamination reactions. The scope of the catalytic reactions has been investigated with thirty-five different combinations of click reactions and six different combinations of the hydroamination of alkynes.

Full text of DOI:10.1039/c7dt03796a

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Efficient extraction of sulfate from water using
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Large CuI8 Chalcogenone Cubic Cages with Non-interacting
Counter Ion
Received 00th January 20xx,
Accepted 00th January 20xx
Katam Srinivasa and Ganesan Prabusankar*a
−
−
Two mega size copper(I) cubic cages, [{Cu(Bptp)}8(PF6−)](PF6
) ) (2) supported by
(1) and [{Cu(Bpsp)}8(PF6−)](PF6
7
7
DOI: 10.1039/x0xx00000x
imidazole-2-chalcogenone ligands (Bptp
= 2,6-bis(1-isopropylimidazole-2-thione)pyridine or Bpsp = 2,6-bis(1-
www.rsc.org/
isopropylimidazole-2-selone)pyridine) have been synthesized and characterized. The formation of ionic salts 1 and 2 were
confirmed by FT-IR, multinuclear (1H, 13C, 31P and 19F) NMR, UV-vis, TGA, CHN analysis, BET, single crystal X-ray diffraction
and powder X-ray diffraction techniques.To the best of our knowledge, these are the first examples of octanuclear
copper(I) cluster in a perfect cubic architecture with copper-copper distances of 8.413 Å or 8.593 Å. Interestingly, these
anion-centered CuI8 cubic arrangements are not supported by cubic centered ions or face centered molecules. Formation
of cationic cubic cages were accompanied by the association of twelve ligands (Bptp or Bpsp) with eight trigonal planar
−
−
[CuSe3] vertex. The cationic charge of cubic cages were satisfied by eight PF6 counter anions, in which one of the PF6
anion occupies at the centre of Cu8 cube without any interaction. The copper(I) cubic cages are found to be highly active
catalysts in click chemistry as well as hydroamination reactions. The scope of the catalytic reactions have been
investigated with thirty five different combinations in click reactions and six different combinations in hydroamination of
alkynes.
promising features in catalysis due to the tunable σ-donor and
Introduction
π-accepting nature of imidazole-2-chalcogenone.8 Surprisingly,
the catalytic efficiency of copper-imidazole-2-chalcogenone
The chemistry of copper-NHC (NHC = N-heterocyclic carbene)
has attracted much attention in the past two decades with
invoking requirements in catalysis.1 The most of the known
copper-NHC molecules are mononuclear, dinuclear, trinuclear
or tetranuclear.2 Though, more than twelve hundred articles
have been reported (according to the SciFinder search on
“Copper Carbene”) related to the copper carbene chemistry,
the NHC-Cu clusters are rare.3 Unlike phosphine based copper
clusters,4 the penta5 or higher nuclear copper-NHC derivatives
complexes is better than copper-NHC complexes. Herewith we
I
report
the
first
perfect
Cu8
cubic
cages
−
−
−
[{Cu(Bptp)}8(PF6 )](PF6 )7
(1 (2)
) and [{Cu(Bpsp)}8(PF6−)](PF6 )7
supported by imidazole-2-chalcogenone ligands (Bptp = 2,6-
bis(1-isopropylimidazole-2-thione)pyridine or Bpsp = 2,6-bis(1-
isopropylimidazole-2-selone)pyridine). To the best of our
knowledge,
as of now.
1 and 2 are the large copper cubic cages isolated
and their catalytic applications are limited due to strong
σ
donor and poor accepting nature of NHC along with steric
π
Experimental
hindrance.6 The search for the suitable NHC or analogues of
NHC type ligands to isolate the polynuclear copper clusters or
cages are in great demand.7 Therefore it is one of the most
challenging task to design the synthetic strategy using NHC or
NHC analogues for clusters or cages of specific nuclearity with
shape.7d-l Recently, the NHC analogues of imidazole-2-
chalcogenone copper(I) complexes have been reported with
Materials
All manipulations were carried out under argon atmosphere
using standard Schlenk techniques. The solvents were
purchased from commercial sources and purified according to
standard procedures and freshly distilled under argon
atmosphere prior to use.9 Unless otherwise stated, the
chemicals were purchased from commercial sources. 1,1'-
(pyridine-2,6-diyl)bis(3-isopropyl-1H-imidazol-3-ium)bromide,
10
2,6-Bis(1-isopropylimidazole-2-thione)pyridine
(
Bptp
)
and
2,6-bis(1-isopropylimidazole-2-selone)pyridine (Bpsp) ligands
were synthesized as reported.11 2,6-dibromo pyridine, Sulphur
powder, selenium powder and [Cu(CH3CN)4]PF6 were
purchased from Sigma Aldrich and used as received.
Instrumentation
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FT-IR measurement (neat) was carried out on a Bruker Alpha-P Found: C, 32.7; H, 3.8; N, 12.8. 1H NMR (DMSO-d6, 400 MHz):
Fourier transform spectrometer. The UV-vis spectra were 1.36-1.37 (d, 2((CH3)2CH), 12H), 4.92 (m, 2(CH3)2CH, 2H), 7.88
measured on
a
T90+ UV-visible spectrophotometer. (d, imidazole, 2H), 8.01 (d, imidazole, 2H), 8.14-8.15 (d,
Thermogravimetric analysis (TGA) was performed using a pyridine, 2H), 8.45 (t, pyridine, 1H) ppm. 13C NMR (DMSO-d6,
TASDT Q600, Tzero-press. NMR spectra were recorded on 100 MHz): 21.20 ((CH3)2CH), 51.57 ((CH3)2CH), 118.79
Bruker Ultrashield-400 spectrometers at 25 °C unless (pyridine), 122.26 (imidazole), 122.71 (imidazole), 143.71
otherwise stated. Chemical shifts are given relative to TMS and (pyridine), 148.51 (pyridine), 154.19 (C=Se) ppm. 31P NMR
were referenced to the solvent resonances as internal (DMSO-d6, 161 MHz):
standards. Elemental analyses were performed by the Euro EA- NMR (DMSO-d6, 376 MHz):
300 elemental analyser. The crystal structures of and were IR (neat): ῡ 3156(w), 2977(w), 1692(w), 1574(m), 1458(s),
−
157.32 to -130.98 (sept, PF6) ppm. 19F
71.06 to -69.17 (d, PF6) ppm. FT-
−
1
2
measured on an Oxford Xcalibur 2 diffractometer. Single 1420(s), 1341(m), 1217(w), 1116(m) (C=Se), 1073(w), 1045(w),
crystals of complexes suitable for the single crystal X-ray 829(vs) (P‒F), 758(m), 732(m), 677(m), 586(m), 554(s) (P‒F)
analysis were obtained from their reaction mixture at room cm-1.
Cu(I) catalysts catalysed azide–alkyne cycloaddition reactions
temperature and the suitable single crystals for X-ray
structural analysis were mounted at room temperature (298 K)
in inert oil under an argon atmosphere. Using Olex2,12 the
structure was solved with the ShelXS13 structure solution
program using Direct Methods and refined with the
olex2.refine refinement package using Gauss-Newton
minimization. Absorption corrections were performed on the
basis of multi-scans. Non-hydrogen atoms were anisotropically
refined. Hydrogen atoms were included in the refinement in
calculated positions riding on their carrier atoms. No restraint
has been made for any of the compounds. CCDC 1573682 and
1573683 contains the supplementary crystallographic data for
this paper. These data can be obtained free of charge from the
(CuAAC). Catalyst 1 or 2 (1 mol%), azide (1 mmol) and terminal
alkyne (1.2 mmol) were placed in an oven dried schlenk flask.
The reaction mixture was then allowed to stir at room
temperature and the progress of the reaction was monitored
by thin layer chromatography. The solid mass obtained was
dissolved in ethyl acetate and passed through silica gel
column. The solvent has been removed by rotary evaporator
and the residue washed several times with n-hexane yielded
pure desired products. All the isolated products were well
characterized by H and 13C NMR and few products (Ia
1
,
Ib,
IIa
and IIb) were also characterized by single crystal X-ray
diffraction analysis.
Cambridge
Crystallographic
Data
Centre
via
Cu(I) catalysts mediated hydroamination of terminal alkynes with
www.ccdc.cam.ac.uk/data_request/cif or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK; fax: +44 1223 336 033; or e-mail:
deposit@ccdc.cam.ac.uk.
substituted anilines. Catalysts
1 or 2 (1 mol %) and AgBF4 (1 mol
%) were placed together in an oven dried schlenk flask. The
schlenk flask was then evacuated and refilled with nitrogen
two to three times. Subsequently, acetonitrile (1 mL) was
added to the mixture and was allowed to stir at room
temperature for 5-10 minutes. After which, the corresponding
arylamine (0.6 mmol) and terminal alkyne (0.50 mmol) were
added successively. The resulting mixture was allowed to stir
at 70 ºC for the appropriate time and the progression of the
reactions were determined by thin layer chromatography. And
the isolated imines were well characterized by 1H and 13C NMR
spectroscopy.
Synthesis of 1. [Cu(CH3CN)4]PF6 (0.069 g, 0.185 mmol) was
dissolved in acetonitrile (3 mL) in an oven dried Schlenk flask
under inert atmosphere, to which Bptp (0.100 g, 0.278 mmol)
in chloroform was added dropwise and was allowed to stir for
12 h. Yield: 93% (0.128 g, based on [Cu(CH3CN)4]PF6). M.p.:
220-223 °C (melting). Elemental analysis calcd (%) for
C23.5H32.5N7.5S3Cu1P1F6 (724.76): C, 38.94; H, 4.52; N, 14.49; S,
13.27; Found: C, 38.8; H, 4.5; N, 14.7; S, 13.3. 1H NMR (DMSO-
d6, 400 MHz): 1.37-1.39 (d, 2((CH3)2CH), 12H), 4.90-4.94 (m,
2(CH3)2CH, 2H), 7.74 (d, imidazole, 2H), 7.86 (d, imidazole, 2H),
8.07-8.08 (d, pyridine, 2H), 8.39-8.43 (t, pyridine, 1H) ppm. 13
C
NMR (DMSO-d6, 100 MHz): 21.03 ((CH3)2CH), 49.40 ((CH3)2CH),
116.88 (pyridine), 119.99 (imidazole), 120.36 (imidazole),
142.97 (pyridine), 147.56 (pyridine), 155.87 (C=S) ppm. 31P
Results and discussion
Synthesis and characterization
The octanuclear copper(I) cubic clustes
in excellent yield by treating [Cu(CH3CN)4]PF6 with an
appropriate amount of Bptp or Bpsp in
1 and 2 were isolated
NMR (DMSO-d6, 161 MHz):
19F NMR (DMSO-d6, 376 MHz):
−
157.36 to -131.02 (sept, PF6) ppm.
71.05 to -69.16 (d, PF6) ppm.
−
FT-IR (neat): ῡ 3156(w), 2978(w), 1671(w), 1596(m), 1459(s),
1400(s), 1342(m), 1279(w), 1221(s), 1130(m) (C=S), 1070(w),
995(w), 828(vs) (P‒F), 730(m), 682(m), 553(s) (P‒F) cm-1.
acetonitrile/chloroform mixture (Scheme 1). Pyridine-based
organo dichalcogenone ligands Bptp and Bpsp were
synthesized in a single step via the reactions of pyridine
bridged imidazolium dibromide derivatives with elemental
chalcogen powder in the presence of K2CO3 in good yield.
Synthesis of 2. [Cu(CH3CN)4]PF6 (0.055 g, 0.146 mmol) was
dissolved in acetonitrile (3 mL) in an oven dried Schlenk flask
under inert atmosphere, to which Bpsp (0.100 g, 0.220 mmol)
in chloroform was added dropwise and was allowed to stir for
12 h. Yield: 81% (0.105 g, based on [Cu(CH3CN)4]PF6). M.p.:
215-216 °C (melting). Elemental analysis calcd (%) for
C23.5H32.5N7.5Se3Cu1P1F6 (865.45): C, 32.61; H, 3.79; N, 12.14;
The ionic salts 1 and 2 were confirmed by FT-IR, multinuclear
(1H, 13C, 31P and 19F) NMR, UV-vis, TGA, CHN analysis, BET,
single crystal X-ray diffraction and powder X-ray diffraction
techniques.
1 and 2 are stable under ambient conditions for
2 | J. Name., 2012, 00, 1-3
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several months and soluble in polar solvents such as imidazole-2-chalcogenone can be an ideal replacement for
1
acetonitrile and DMSO. In H NMR, the isopropyl CH signal is anionic ligand [(iPrO)2PSe2]- to generate octanuclear copper(I)
upfield shifted by around 0.3 ppm, while imidazole CH signals clusters. Though several copper(I) cubic cages have been
are downfield shifted by 0.4 to 0.9 ppm. The hydrogen at 4th isolated with centered atom (mainly halogen or chalcogen or
position in the pyridine unit appeared to be downfield shifted hydride
etc),
only
one
copper(I)
cubic
cage,
by 0.4 ppm, while the other protons at 3rd and 5th position in [Cu8{Se2P(OiPr)2}6](PF6)2 has been reported without centered
pyridine moiety appears to be upfield shifted by 0.4 to 0.6 ppm atom,16a where the Cu····Cu seperations are not equal
compared to free ligands. The 13C NMR spectra of the copper(I) (3.216(1) and 3.220(1) Å).
complexes and
the resonances when compared to the respective ligand centered atom or molecule.
1
and
2
are the first examples of
1
2 are mostly the same with very little shift in perfect copper(I) cubic cages known without non-interacting
precursors. In 13C NMR, the C=S and C=Se signal in
appeared to be upfield shifted (5 ppm for and 1 ppm for
1
and
2
2
1
compared to corresponding ligand), respectively. This can be
attributed to the strong donor and poor π accepting nature
σ
of the carbene carbon upon complexation with copper(I). The
31P NMR spectra shows a septet for the presence of PF6
counter ions in
1
and
2
. The 19F NMR spectra depicts a doublet
for PF6 counter ions in
1
and
2.
8
Cu
Cu
Cu
Cu
N
N
E
[Cu(CH3CN)4]PF6
Cu
Cu
N
CH3Cl/CH3CN,
12 h, RT
E
N
N
Cu
Cu
=
E = S (Bptp),
Se (Bpsp).
8 [PF6]
E = S (1) or Se (2)
Scheme 1 Synthesis of 1 and 2.
The ionic salts
1
and
2
crystallized in the cubic space group, Pn-
and are furnished in table
3n. The crystallographic data for
1
2
S1 (see Supporting information-1). The solid-state structures
with selected bond lengths and bond angles are reported in
figures 1. Liu and co-workers have reported several
octanuclear copper(I) clusters using phosphorus-chalcogenide
as suitable ligand, where the presence of interacting
elementary ion into the center of a centerosymmetric copper
cluster or cubic cage is very essential to retains the original
symmetry of the cluster.14 Notably, a tremendous efforts have
been made to alter the size of the octanuclear copper core.15
The size of the metal core can be altered based on the size and
charge of anion present in the center of cage.16 In all these
aforementioned Cu8(I) cubic cages, the edge length between
Cu(I)····Cu(I) in octanuclear copper cubic cage ranges from
2.859 Å to 3.225 Å.16c Surprisingly, the known Cu8(I) cubic
cages were isolated only using [(iPrO)2PE2]- (E = Se or S) ligands.
However it appears that the (i) similar such cages have never
been reported with any other ligands; (ii) octanuclear copper
cubic cages with larger than Cu(I)····Cu(I) edge length of 3.225
Å have never been isolated. Thus, the neutral donor ligand,
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Fig. 1 (I) The solid state structure of 1 and 2. Hydrogen atoms and PF6 counter anions
have been omitted for the clarity. Dotted lines between copper centres are imaginary
lines. (II) Core structure of cubic cage. Hydrogen atoms, carbon atoms and PF6 counter
anions have been omitted for the clarity. Dotted lines between copper centres are
Moreover, the theremal stability of
1
and
2
is not comparable
is much
depicted enough stability until 200 °C.
shows a little weight loss (5%), which can be
attributed to the phase change in . Subsequently shows
(Figure 2). The thermal decomposition pathway of
1
imaginary lines. (III) Coordination environment of copper(I) in 1 and 2. Selected bond clear than
lengths (Å) and angles (°) for 1: C(1)–S(1), 1.700(2), S(1)–Cu(1), 2.249 (6), S(1)–Cu(1)–
2. 1 and 2
Then compound
1
S(1), 120.0, N(1)–C(1)–N(2), 105.07(19), N(1)–C(1)–S(1), 125.17(18), N(2)–C(1)–S(1),
129.74(18), C(1)–S(1)–Cu(1), 112.72(8). Selected bond lengths (Å) and angles (°) for 2:
C(1)–Se(1), 1.856(5), Se(1)–Cu(1), 2.338(5), Se(1)–Cu(1)–Se(1), 120.0, N(1)–C(1)–N(2),
105.0(4), N(1)–C(1)–Se(1), 124.5(4), N(2)–C(1)–Se(1), 130.4(4), C(1)–Se(1)–Cu(1),
109.45(14).
1
1
o
enough stability until 305 C then observed a sudden weight
loss in a single step to give Cu2S residue (26%, Calcd. 23%),
which can be attributed to the decomposition of organic
moieties in 1. Besides, 2 depicts gradual weight loss from its
melting point (210 oC) through minor phase transformations
along with the organic moieties decomposition to yield Cu3Se2
residue (39%, Calcd. 40%).
The faces of the cubanes
distance between copper atoms in
are equal. The diagonal distance between Cu····Cu is 14.571 Å
(for ) and 14.883 Å (for ). The Cu····Cu diagonal distance
found in and are nearly 50% shorter than the diagonal
Fe····Fe distance found in the large FeII/NiII face capped cubic
box (25.622 Å).17 The solid-state structures of complexes
and
consists of one cubic [Cu8(Bptp
Bpsp)12]8+ cation and eight
[PF6]- anions, in which each copper center is linked by three
ligands. The E–Cu–E bond angles around copper centers in
and are in favour of trigonal planar arrangement.
The carbon–sulfur bond lengths in
1
and
2
are open. Notably, the
1
(8.413 Å) and (8.593 Å)
2
1
2
UV-visible absorption studies
1
2
The solution state and solid state UV-visible absorption spectra
of
1 and 2 are compared with Bptp and Bpsp, respectively
1
(Figure 3). Almost similar absorpꢀon paꢁerns for π → π* (200-
300 nm) and n → π* (300–350 nm) transitions are observed in
the solution state UV-vis spectroscopy for both the ligands and
2
/
1
their copper(I) complexes (
notieced for Bpsp and compared to Bptp and
in the solid state UV-vis study, complexes and
1
and
2
). Bathchromic shift was
. Interestingly,
depicted the
2
2
1
1
is 1.700(2) Å, which is
closer to that of (C=S, 1.61 Å) double bond18a than a single
bond distance (C–S, 1.83 Å).18b The carbon–selenium bond
1
2
bathochromic shift along with broadening of absorption band
due to a strong molecular association in solid state form
compared to their solution state study.
length in
bond distance (1.94 Å)19a than a C=Se double bond distance
(1.74 Å).19b The S–Cu distance (2.249 (6) Å) in complex
is
slightly shorter than that of dichloro-[(ƞ3-S,S,N)(2,6-bis){[N-
isopropyl]imidazole-1-ylidene-2-thione}-pyridine copper(II)]
(2.30-2.32 Å).20 The Se–Cu bond length (2.338(5) Å) found in
2 is 1.856(5) Å, which is closer to that of a C–Se single
1
2
is slightly elongated than that of [(IPr=Se)2Cu]X and
[(IMes=Se)2Cu]X (Where X = BF4 and ClO4) (2.24-2.27 Å).8c
PXRD and Thermogravimetric analysis
The PXRD pattern of bulk crystalls of
1 and 2 are nearly
comparable with calculated PXRD pattern of corresponding
single crystal data (See supporting information 1, Figure S16
and S17), which clealy supports the phase purity of bulk
samples of 1 and 2.
Fig. 3 UV-vis spectra of Bptp, Bpsp, 1 and 2 (Solution state in acetonitrile at 25 oC, 2.8 x
10-5 M).
Miscellaneous investigations
Considering the size of these cages,
1 was subjected to BET
analysis. The maximum quantity adsorbed at STP is 1.45 cm3/g,
which is not very impressive (See Supporting Information,
Figure S15). Besides, the attempts to transmetallate copper in
1
by gold using (dms)AuCl were unproductive (See Supporting
Information 2, Note 1). Both 1 and 2 undergoes dissociation to
result the starting materials by depositing gold metal on the
surface of the flask. In order to understand the host-guest
property of these cages, the preliminary studies were carried
Fig. 2 TGA curves of 1 and 2 from 30 to 550 °C under a nitrogen atmosphere with a
heating rate of 10 °C min−1. For 1: residual wt 26%, calc. wt 23%; For 2: residual wt 39%,
calc. wt 40%.
out between
1
and pyrene or perylene (See supporting
4 | J. Name., 2012, 00, 1-3
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information 2, Note 2).
1
act as a host for both perylene and
@pyrene, respectively.
is much faster than pyrene.
was not successful.
pyrene to result
1@perylene and 1
Notably the perylene uptake by
1
Attempt to introduce C60 into
1
Catalytic examinations
Subsequently,
1 and 2 were employed for azide-alkyne
cycloaddition reactions to produce 1,2,3-triazoles under mild
conditions (Scheme 2, Table 1). Though, the catalytic reactions
were promising both in water medium (entry 1) and under
neat conditions (entry 2), the less reaction time was noticed
for the solvent free reaction over the water media reaction.
Scheme 2 Catalysts 1 and 2 mediated one-pot synthesis of triazoles.
Table 1 Optimization studies for CuAAC reaction mediated by Copper(I) catalysts 1 and
2.a
Entry
Catalyst
Cat.
Solvent
Time
(min)
30
Yield
(%)b
>99
>99
98
(mol%)
1
2
3
4
5
6
7
1
1
1
water
neat
neat
neat
neat
neat
neat
1
15
1
0.5
0.1
2
60
1
180
15
94
1
>99
>99
45
2
1
20
[Cu(CH3CN)]PF6
1
60
aReaction conditions: phenyl acetylene (0.6 mmol), benzyl azide (0.5 mmol) and
solvent (2 mL). bIsolated yield
Besides, the yield of Ia was decreased, when the catalyst mol%
was decreased (for 0.5 mol%, see entry 3 and for 0.1 mol%,
see entry 4). However, the extension of time led to the
isolation of quantitative yield of Ia. On the other hand, not
much improvement in the yield was observed by reducing the
time or increasing catalyst loading (2 mol%, entry 5). Notably,
catalyst
2 requires little longer time than the catalyst 1 (entry
6). In addition, less amount of product formation (Ia) was
observed under solvent free conditions using only
[Cu(CH3CN)4](PF6) (entry 7). Further, we have explored the
scope of the reactions using benzyl azide, 4-nitrobenzylazide,
Chart 1 aReaction conditions: alkyne (1.2 mmol), azide (1 mmol), Catalyst 1 and/or 2 (1
mol%), neat, isolated yield.
1
The isolated products were characterized by H and 13C NMR
4-bromobenzylazide,
phenylazide with a varieties of terminal alkynes using 1 mol%
of and/or as catalysts under solvent free conditions. The
phenylazide
and
2,4,6-trimethyl
spectroscopy. The solid state structures of isolated products Ia
Ib IIa, and IIb were additionally evaluated by single crystal X-
ray diffraction analysis.
In addition to this the catalysts longevity has been investigated
using 1 mol% of catalyst with benzyl azide and phenyl
,
,
1
2
yield of the product was excellent (>95%, Chart 1).
1
acetylene in neat conditions at room temperature and it was
found that the same catalyst can produce appreciable yields
for eight successive cycles. Moreover, PXRD studies on reused
catalyst revealed that the catalyst exists as an intact octa-
nuclear cage rather than dissociated molecules (Figure 4 and
also See supporting information-2, Note 3).
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ARTICLE
Journal Name
N
Markovnikov Product
(100%)
1 mol% Catalyst,
1 mol% AgBF4
CH3CN, 70 oC,
2 h
NH2
N
Anti-Markovnikov Product
(0%)
Scheme 4 Hydroamination of alkynes by catalysts 1 and 2.
Table
2 Optimization studies for hydroamination reaction mediated by Copper(I)
catalysts 1 and 2.a
Entry
Catalyst
Cat.
Solvent
Time
(h)
2
Yield
(%)b
>99
>99
98
(mol%)
Fig. 4 Longevity studies on catalyst 1 (1 mol%) in click catalysis using benzyl azide (1
1
2
3c
4d
5
1
1
1
1
1
1
1
1
1
1
1
CH3CN
CH3CN
CH3CN
CH3CN
Benzene
CH3OH
THF
mmol) and phenyl acetylene (1.2 mmol) under neat conditions at room temperature.
2
2
1
3
Since the copper catalyzed one-pot synthesis of triazoles, by a
three-component reaction (organic bromide, sodium azide and
an alkyne; in order to avoid azide isolation) is very much
1
12
2
72
1
20
6
1
1
2
70
demanding,21 the
1 and 2 mediated one-pot reactions were
7
8e
2
65
performed in water (Scheme 3).
1
CH3CN
CH3CN
CH3CN
2
90
9
AgBF4
Ag(OTf)
12
12
30
NaN3
10
25
1 mol%
Catalyst 1 or 2
N
aReaction conditions: phenyl acetylene (0.5 mmol), 2,6-dimethylaniline (0.6
mmol) and solvent (2 mL). bIsolated yield, cwithout AgBF4, dreaction performed at
room temperature, ewith Ag(OTf).
R'
N
N
R
RT, H2O
R
R'
Br
> 90%
The reaction proceeds very smoothly with both the catalysts in
presence of AgBF4 in 2 h (entry 1 and 2). Besides the absence
of AgBF4 required slightly longer time (3 h) for the completion
Scheme 3 Catalysts 1 and 2 mediated one-pot synthesis of triazoles.
The catalysts
1 and 2 gave remarkable yield (> 90%) from of hydroamination reaction (entry 3). On the other hand,
reactants with electron-rich or electron-poor azides and moderate yield was noticed for the same reaction performed
alkynes (See Supporting information-2, Chart S1). The catalytic at RT for 12 h (entry 4). However, benzene (entry 5), methanol
efficiency of
systems.22 Thus, it was realized that the co-coordinatively yields
1 and 2
are comparable with cationic [Cu(NHC)2]+ (entry 6) and tetrahydrofuran (entry 7) produced moderate
.
The presence of Ag(OTf) along with catalyst 1 gave fairly
unsaturated Cu(I) centers with trigonal planar arrangement good yield (entry 8). However, AgBF4 presence is significant in
along with open face cubic arrangement allow the CuAAC this transformation. The starting material conversion was not
reaction substrates to conveniently approach the metal center appriciable only with AgBF4 (entry 9) or Ag(OTf) (entry 10)
on cubic surface to trigger the reaction (See supporting under longer reaction times. Therefore acetonitrile was
information-2).
anticipated to be the best solvent for this transformation with
were highly active and quantitative yields. The catalysts were highly active (yield,
Moreover, the catalysts
1
and
2
selective (Markovnikov’s product) for the hydroamination of from 92 to 99%) with excellent functional group tolerance
terminal alkynes with arylamines (Scheme 4, Table 2). The (Chart 2) and the catalytic efficiency of
reaction was performed between phenyl acetylene and 2,6- Cu-NHC catalysts.22b,23
1 or 2 are on par with
dimethyl aniline in acetonitrile using 1 mol% catalyst
along with 1 mol% AgBF4 as cocatalyst.
1 or 2
6 | J. Name., 2012, 00, 1-3
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ARTICLE
Notes and references
1
For selected examples: (a) J. Wang, X. Cao, S. Lv, C. Zhang, S.
Xu, M. Shi and J. Zhang, Nat. Commun. 2017, 14625, 1-10; (b)
F. Lazreg, F. Nahra and C. S. J. Cazin, Coord. Chem.
Rev. 2015, 293-294, 48-79; (c) S. Díez-González and S. P.
Nolan, Acc. Chem. Res. 2008, 41, 349–358; (d) E. A. Romero,
N
N
R. Jazzar and G. Bertrand, Chem. Sci. 2017,
Egbert, C. S. J. Cazin and S. P. Nolan, Catal. Sci. Technol.
2013, , 912‒926; (f) W. Kirmse, Angew. Chem. Int. Ed. 2003,
8, 165; (e) J. D.
VIa, 98%, 96%
VIb, 95%, 97%
3
42, 1088–1093; (g) S. Gaillard, C. S. J. Cazin and S. P. Nolan,
Acc. Chem. Res. 2012, 45, 778–787; (h) N. Marion, NHC-
copper, silver and gold complexes in catalysis, RSC Catalysis
Series (2011), 6(N-Heterocyclic Carbenes), 317–344; (i) V.
Charra, P. Frémont and P. Braunstein, Coord. Chem. Rev.
2017, 341, 53-176.
N
N
2
(a) X. Hu, I. Castro-Rodriguez and K. Meyer, J. Am. Chem. Soc.
12237-12245; (b) X. Liu and W. Chen,
2012, 31 6614−6622; (c) M.
2003, 125,
Organometallics
VIIc, 94%, 96%
VIc, 99%, 95%
,
Nonnenmacher, D. Kunz, F. Rominger, Organometallics 2008,
27, 1561–1568; (d) B. Liu, S. Pan, B. Liu and W. Chen, Inorg.
Chem. 2014, 53, 10485-10497; (e) B. Liu, B. Liu, Y. Zhou and
W. Chen, Organometallics 2010, 29, 1457-1464; (f) X. Hu, I.
N
Castro-Rodriguez and K. Meyer, J. Am. Chem. Soc. 2003, 125
,
N
12237-12245; (g) A. Biffis, C. Tubaro, E. Scattolin, M. Basato,
G. Papini, C. Santini, E. Alvarez and S. Conejero, Dalton Trans.
2009, 35, 7223-7229; (h) N. Sinha, F. Roelfes, A. Hepp, C.
Mejuto, E. Peris and F.E. Hahn, Organometallics 2014, 33
6898-6904.
,
VIIc, 98%, 97%
VIIc, 92%, 96%
3
(a) A. Makarem, R. Berg, F. Rominger and B. F. Straub,
Angew. Chem. Int. Ed. 2015, 54, 7431–7435; (b) S. Simonovic,
A. C. Whitwood, W. Clegg, R. W. Harrington, M. B.
Hursthouse, L. Male, R. E. Douthwaite. Eur. J. Inorg. Chem.
2009, 1786–1795; (c) H. Sun, K. Harms and J. Sundermeyer. J.
Am. Chem. Soc. 2004, 126, 9550–9551; (d) A. Makarem, R.
Berg, F. Rominger and B. F. Straub, Angew. Chem. Int. Ed.
2015, 54, 7431–7435; (e) S. Gu, J. Huang, X. Liu, H. Liu, Y.
Zhou and W. Xu, Inorg. Chem. Commun. 2012, 21, 168–172;
(f) W. J. Humenny, S. Mitzinger, C. B. Khadka, B. K.
Najafabadi, I. Vieiraa and J. F. Corrigan, Dalton Trans. 2012,
41, 4413-4422; (g) A. Sathyanarayana, B. P. R. Metla, N.
Sampath and G. Prabusankar, J. Organomet. Chem. 2014,
772-773, 210-216; (h) N. Sinha and F. E. Hahn, Acc. Chem.
Res., 2017, 50, 2167–2184.
For selected examples: (a) R. S. Dhayal, W. E. van Zyl and C.
W. Liu, Acc. Chem. Res., 2016, 49, 86–95; (b) M. Shieh, C.-Y.
Miu, Y.-Y. Chu and C.-N. Lin, Coord. Chem. Rev., 2012, 256
637-694; (c) C. Femoni, M. C. Iapalucci, F. Kaswalder, G.
Longoni and S. Zacchini, Coord. Chem. Rev., 2006, 250, 1580-
1604; (d) R. Ahlrichs, A. Eichhöfer, D. Fenske, K. May and H.
Sommer, Angew. Chem. Int. Ed., 2007, 46, 8254-8257; (e) R.
Ahlrichs, D. Fenske, M. McPartlin, A. Rothenberger, C.
Chart 2 Isolated products of hydroamination reaction catalyzed by copper(I) catalysts 1
and 2.a aReaction conditions: alkyne (0.5 mmol), substituted aniline (0.6 mmol) and
solvent (2 mL).
Conclusions
In summary, the large octanuclear Cu(I) cubic cages (
supported by organo dichalcogenones were synthesized and
characterized. and are the first examples of perfect Cu(I)
cubic cage with Cu(I)····Cu(I) distance of 8.413 Å (for ) and
8.593 Å (for ). Formation of cationic cubic cages were
1 and 2)
1
2
1
2
4
accompanied by the association of twelve ligands (Bptp or
Bpsp) with eight trigonal planar [CuSe3] vertex. The cationic
,
−
charge of cubic cages were satisfied by eight PF6 counter
−
anions, in which one of the PF6 anion occupies at the centre
of Cu8 cube without any interaction. Moreover,
1 and 2 are
found to be very active catalysts in click chemistry under mild
condition, one pot synthesis of triazoles as well as the selective
hydroamination of terminal alkynes.
Schrodt and S. Wieber, Angew. Chem. Int. Ed., 2005, 44
3932–3936.
,
5
6
Z. Han, G. Zhang, M. Zeng, D. Yuan, Q. Fang, J. Li, J. Ribas and
H. Zhou, Inorg. Chem., 2010, 49, 769–771.
(a) G. Kong, X. Xu, C. Zou and C. Wu, Chem. Commun. 2011,
47, 11005–11007; (b) K. Oisaki, Q. Li, H. Furukawa, A. U.
Czaja and O. M. Yaghi, J. Am. Chem. Soc. 2010, 132, 9262–
9264: (c) J. Chun, H. S. Lee, II G. Jung, S. W. Lee, H. J. Kim and
S. U. Son, Organometallics 2010, 29, 1518–1521; (d) J. Luo, J.
Conflicts of interest
The authors have no conflicts of interest to declare for this
article.
Wang, G. Li, Q. Huo and Y. Liu, Chem. Commun., 2013, 49
,
11433-11435; (e) C. Tubaro, A. Biffis, R. Gava, E. Scattolin, A.
Volpe, M. Basato, M. M. Díaz-Requejo and P. J. Perez, Eur. J.
Org. Chem. 2012, 1367–1372.
For selected examples: (a) T. Bollermann, G. Prabusankar,
C. Gemel, M. Winter, R. W. Seidel and R. A. Fischer, Chem.
Eur. J. 2010, 16, 8846-8853; (b) A. Makarem, R. Berg, F.
Acknowledgements
We gratefully acknowledge the DST-SERB (SB/S1/IC-07/2014)
for financial support. KS thank UGC for the fellowship. We
thank Dr. Raghavender Medishetty for the BET measurement.
7
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Rominger and B. F. Straub, Angew. Chem. Int. Ed. 2015, 54
7431 –7435; (c) M. A. Fard, T. I. Levchenko, C. Cadogan, W. J.
Journal Name
,
17 W. Meng, B. Breiner, K. Rissanen, J. D. Thoburn, J. K. Clegg
and J. R. Nitschke, Angew. Chem. Int. Ed. 2011, 50, 3479 –
3483.
Humenny and J. F. Corrigan, Chem. Eur. J. 2016, 22, 4543–
4550; (d) J. Guo, Y. –W. Xu, K. Li, L. –M. Xiao, S. Chen, K. Wu, 18 (a) B.V. Trzhtsinskaya and N.D. Abramova, J. Sulfur Chem.
X. –D. Chen, Y–Z. Fan, J. –M. Liu and C. –Y. Su, Angew. Chem. 1991, 10, 389; (b) W. Jia, Y. Huang and G. Jin, J. Organomet.
Int. Ed. 2017, 56, 1–6; (e) S. Durot, J. Taesch and V. Heitz, Chem. 2009, 694, 4008–4013.
Chem. Rev., 2014, 114, 8542–8578; (f) W. M. Bloch and G. H. 19 (a) M. M. Kimani, C. A. Bayse and J. L. Brumaghim, Dalton
Clever, Chem. Commun., 2017, 53, 8506–8516; (g) M. Tegoni
and M. Remelli, Coord. Chem. Rev., 2012, 256, 289–315; (h)
A. Schmidt, A. Casini and F. E. Kühn, Coord. Chem. Rev., 2014,
Trans., 2011, 40, 3711–3723; (b) M. M. Kimani, D. Watts, L.
A. Graham, D. Rabinovich, G. P. A. Yap and J. L. Brumaghim,
Dalton Trans., 2015, 44, 16313-16324.
275, 19–36; (i) W. Wang, Y. –X. Wang and H. –B. Yang, 20 (a) J. R. Miecznikowski, M. A. Lynn, J. P. Jasinski, W. Lo, D. W.
Chem. Soc. Rev., 2016, 45, 2656-2693; (j) Y. Bai, Q. Luo and J.
Liu, Chem. Soc. Rev., 2016, 45, 2756-2767; (k) H. Li, Z. –J. Yao,
D. Liu and G. –X. Jin, Coord. Chem. Rev., 2015, 293–294, 139–
157; (l) K. Byrne, M. Zubair, N. Zhu, X. –P. Zhou, D. S. Fox, H.
Zhang, B. Twamley, M. J. Lennox, T. Düren and W. Schmitt,
Bak, M. Pati, E. E. Butrick, A. E. R. Drozdoski, K. A. Archer, C.
E. Villa, E. G. Lemons, E. Powers, M. Siu, C. D. Gomes, N. A.
Bernier and K. N. Morio, Polyhedron 2014, 80, 157–165; (b) J.
R. Miecznikowski, M. A. Lynn, J. P. Jasinki, E. Reinheimer, D.
W. Bak, M. Pati, E. E. Butrick, A. E. R. Drozdoski, K. A. Archer,
C. E. Villa, E. G. Lemons, E. Powers, M. Siu, C. D. Gomes and
K. N. Morio, J. Coord. Chem. 2014, 67, 29–44.
Nat. Commun. 2017,
N. Mizuno, T.
8, 15268; (m) D. Fujita, Y. Ueda, S. Sato,
Kumasaka and M. Fujita
Nature 2016, 540, 563-566; (n) B. M. Schmidt, T. Osuga, T. 21 C. Wang, D. Ikhlef, S. Kahlal, J. Saillard and D. Astruc, Coord.
Sawada, M. Hoshino and M. Fujita, Angew. Chem. Int. Chem. Rev. 2016, 316, 1-20.
Ed. 2016, 55, 1561-1564; (o) M. M. Conn and J. Rebek, Jr. 22 (a) S. Díez-González and S. P. Nolan, Angew. Chem., Int. Ed.
Chem. Rev., 1997, 97, 1647–1668; (p) P. Ballester, M. Fujita
and J. Rebek Jr. Chem. Soc. Rev., 2015, 44, 392-393; (q) M.
Yoshizawa, J. K. Klosterman and M. Fujita, Angew. Chem. Int.
Ed., 2009, 48, 3418–3438; (r) L.-J. Chen, H.-B. Yang and M.
Shionoya, Chem. Soc. Rev., 2017, 46, 2555-2576.
(a) H. R. Kim II, G. Jung, K. Yoo, K. Jang, E. S. Lee, J. Yun and S.
U. Son, Chem. Commun. 2010, 46, 758–760; (b) M. K.
Barman, A. K. Sinha and S. Nembenna, Green Chem., 2016,
18, 2534-2541; (c) K. Srinivas, C. N. Babu and G. Prabusankar,
Dalton Trans. 2015, 44, 15636–15644; (d) M. Melaimi, R.
Jazzar, M. Soleilhavoup and G. Bertrand, Angew. Chem. Int.
Ed., 2017, 56, 10046–10068; (e) D. J. Nelson, F. Nahra, S. R.
Patrick, D. B. Cordes, A. M. Z. Slawin and S. P. Nolan,
Organometallics 2014, 33, 3640−3645.
2008, 47, 8881-8884; (b) J. D. Egbert, C. S. J. Cazin and S. P.
Nolan, Catal. Sci. Technol. 2013, , 912-926; (c) F. Lazreg, A.
3
M. Z. Slawin and C. S. J. Cazin, Organometallics, 2012, 31
7969-7975.
,
23 M. J. Pouy, S. A. Delp, J. Uddin, V. M. Ramdeen, N. A.
Cochrane, T. B. Gunnoe, T. R. Cundari, M. Sabat and W. H.
Myers, ACS Catalysis 2012, 2, 2182-2193.
8
9
D. D. Perrin and W. L. F. Armarego, Purification of laboratory
chemicals, Pergamon Press, London, 3rd edn, 1988.
10 W. Jia, Y. Dai, H. Zhang, X. Lu and E. Sheng, RSC Adv., 2015, 5,
29491–29496.
11 H. Zhang, W. Jia, Q. Xu and C. Ji, Inorg. Chim. Acta, 2016,
450, 315–320.
12 O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard
and H. Puschmann, J. Appl. Cryst. 2009, 42, 339–341.
13 (a) G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467–
473; (b) G. M. Sheldrick, SHELXL-97, Program for Crystal
Structure Refinement, Universität Göttingen, Göttingen,
1997.
14 (a) J. Galy, A. Mosset, I. Grenthe, I. Puigdomènech, B. Sjöberg
and F. Hultèn, J . Am. Chem. Soc. 1987, 109, 380-386; (b) D.
Armentano, T. F. Mastropietro, M. Julve, R. Rossi, P. Rossi
and G. D. Munno, J. Am. Chem. Soc. 2007, 129, 2740-2741.
15 R. S. Dhayal, W. E. van Zyl and C. W. Liu, Acc. Chem. Res.
2016, 49(1), 86–95.
16 (a) C. W. Liu, B. Sarkar, Y. Huang, P. Liao, J. Wang, J. Saillard
and S. Kahlal, J. Am. Chem. Soc. 2009, 131, 11222–11233; (b)
C. W. Liu, C. -M. Hung, B. K. Santra, H. -C. Chen, H. -H. Hsueh
and J. -C. Wang, Inorg. Chem. 2003, 42, 3216–3220; (c) C. W.
Liu, C. -M. Hung, B. K. Santra, Y. H. Chu, J. -C. Wang and Z.
Lin, Inorg. Chem. 2004, 43, 4306–4314; (d) C. W. Liu, H.-C.
Chen, J. -C. Wang and T. -C. Keng, Chem. Commun. 1998,
1831–1832; (e) C. W. Liu, M. D. Irwin, A. A. Mohamed and J.
P. Fackler, Inorg. Chim. Acta 2004, 357, 3950–3956; (f) C. W.
Liu, C. -M. Hung, H. -C. Chen, J. -C. Wang, T. -C. Keng and K.
Guo, Chem. Commun. 2000, 1897–1898; (g) T. S. Lobana, J. -
C. Wang and C. W. Liu, Coord. Chem. Rev. 2007, 251, 91–110;
(h) J. P. Fackler, Inorg. Chem. 2002, 41, 6959–6972; (i) C. W.
Liu, C. –M. Hung, B. K. Santra, J. –C. Wang, H. –M. Kao and Z.
Lin, Inorg. Chem., 2003, 42 (25), 8551–8556.
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Table of Contends
Synthesis and applications of two mega size octanuclear copper(I) chalcogenone cages have been
reported.