An Antimony(V) Dication as a Z-Type Ligand: Turning on Styrene Activation at Gold

Article abstract of DOI:10.1002/anie.201903964

With the intent to demonstrate that the charge of Z-type ligands can be used to modulate the electrophilic character and catalytic properties of coordinated transition metals, we are now targeting complexes bearing polycationic antimony-based Z-type ligands. Toward this end, the dangling phosphine arm of ((o-(Ph₂P)C₆H₄)₃)SbCl₂AuCl (1) was oxidized with hydrogen peroxide to afford [((o-(Ph₂P)C₆H₄)₂(o-Ph₂PO)C₆H₄)SbAuCl₂]⁺ ([2 a]⁺) which was readily converted into the dicationic complex [((o-(Ph₂P)C₆H₄)₂(o-Ph₂PO)C₆H₄)SbAuCl]²⁺ ([3]²⁺) by treatment with 2 equiv AgNTf₂. Both experimental and computational results show that [3]²⁺ possess a strong Au→Sb interaction reinforced by the dicationic character of the antimony center. The gold-bound chloride anion of [3]²⁺ is rather inert and necessitates the addition of excess AgNTf₂ to undergo activation. The activated complex, referred to as [4]²⁺ [((o-(Ph₂P)C₆H₄)₂(o-Ph₂PO)C₆H₄)SbAuNTf₂]²⁺ readily catalyzes both the polymerization and the hydroamination of styrene. This atypical reactivity underscores the strong σ-accepting properties of the dicationic antimony ligand and its activating impact on the gold center.

Full text of DOI:10.1002/anie.201903964

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Accepted Article
Title: An antimony(V) dication as a Z-type ligand: Turning on styrene
activation at gold
Authors: Ying-Hao Lo and Francois Pierre Gabbai
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An antimony(V) dication as a Z-type ligand: Turning on styrene
activation at gold
Ying-Hao Lo and François P. Gabbaï *[a]
Dedication ((optional))
Abstract: With the intent to demonstrate that the charge of Z-type
ligands can be used to modulate the electrophilic character and
catalytic properties of coordinated transition metals, we are now
targeting complexes bearing polycationic antimony-based Z-type
ligands. Toward this end, the dangling phosphine arm of ((o-
charges on the Lewis acidic main group element, we are now
investigating ligand platforms that would support the formation of
antimony dications, within the coordination sphere of a late
transition metal. It occurred to us that isolating such a complex
may necessitate the use of auxiliary donor functionalities
introduced to tame the high reactivity of the dicationic antimony
moieties.[9] Inspired by the work of Burford on species such as V
which shows that phosphine oxides are privileged ligands for
antimony cations,[10] we have now decided to target complexes of
type VI in which one of the phosphine oxide donors is replaced by
(
Ph
afford [((o-(Ph
readily converted into the dicationic complex [((o-(Ph
2
P)C
6
H
4
)
3
)SbCl
2
AuCl (1) was oxidized with hydrogen peroxide to
+
+
2
P)C
6 4 2 2 6 4
H ) (o-Ph PO)C H )SbAuCl
2
]
([2] ) which was
P)C (o-
)SbAuCl] ([3] ) by treatment with 2 equiv. AgNTf . Both
2
6 4 2
H )
2+
2+
Ph
PO)C H
2 6 4
2
2+
experimental and computational results show that [3] possess a
strong Au→Sb interaction reinforced by the dicationic character of the
a
metalloligand.
In this paper, we describe our first
2+
antimony center. The gold-bound chloride anion of [3] is rather inert
implementation of this idea and its application to gold mediated
catalysis.
and necessitates the addition of excess AgNTf to undergo activation.
2
2+
The activated complex, referred to as [4] [((o-(Ph
2
P)C
readily catalyzes both the polymerization
and the hydroamination of styrene. This atypical reactivity
6 4 2
H ) (o-
2+
2 6 4 2
Ph PO)C H )SbAuNTf ]
underscores the strong -accepting properties of the dicationic
antimony ligand and its activating impact on the gold center.
Although traditionally regarded as laboratory curiosities, Z-type,
Lewis acidic ligands and the complexes they form with transition
metals are now gaining increasing validation in the area of
catalysis[1] where the electron accepting properties of the Lewis
acidic center can be used to modulate the electron density and
catalytic reactivity of the adjacent metal center.[2] The accepting
properties of Z-type ligands can be influenced by a variety of
factors including the nature of the atom acting as the Lewis acid,[3]
its redox state or its coordination environment.[1i,1j] Examples that
illustrate the tunability of these ligand systems include double-
decker complexes of type I where variation of the group 13
element allows for a precise control of the Ni-E interaction[4] or
complexes of type II where the redox state of the antimony center
can be used to adjust the strength of the Au-Sb interaction (Figure
Figure 1. Examples of transition metal complexes that contain Z-type ligands (I
to IV) and outline of work mentioned within (V and VI).
As an entry point for the synthesis of a complex of type VI, we
considered 1, a known gold complex which features a phosphino
arm free of metal coordination.[11] To test if this unit could be
converted into the corresponding phosphine oxide, complex 1
was combined with one equivalent of hydrogen peroxide (Scheme
1
).[5] Based on the principle that cationic main group compounds
are more Lewis acidic than their neutral counterparts,[6] we have
been interested in an approach whereby anion abstraction serves
to enhance the -accepting properties of the Z-type ligand.[7] We
demonstrated this idea in the case of complex III which, upon
conversion into IV by fluoride anion abstraction, became
catalytically active as a result of a stronger PtSb interaction.[8]
With the view of further augmenting the accumulation of positive
1). This reaction afforded complex [2a][Cl] as an air stable solid,
the crystal structure of which (vide infra) confirmed the successful
conversion of one of the three phosphino arms of the ligand into
a phosphine oxide. This complex has also been characterized by
EA and 31P MAS NMR spectroscopy. The latter shows two
signals at 60.2 ppm and 41.6 ppm. The respective 2:1 intensity
ratio measured for these two resonances indicates that they
correspond to the gold-coordinated phosphine and the phosphine
oxide units, respectively. When in solution, [2a][Cl] gives rise to
a second isomer ([2b][Cl]) for which the 31P nucleus of the
[*]
Y.-H Lo and Prof. Dr. F. P. Gabbaï
Department of Chemistry, Texas A&M University
College Station, TX 77843 (USA)
E-mail: francois@tamu.edu
Homepage: http://www.chem.tamu.edu/rgroup/gabbai/
Supporting information for this article is given via a link at the end of
the document.
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2 2
Figure 2. Left: Solid-state structure of [2a][Cl] and [3][NTf ] . Thermal ellipsoids are drawn at the 50% probability level. The phenyl groups are drawn in wireframe,
the. hydrogen atoms, interstitial solvent molecules, and counteranions are omitted for clarity. Relevant metrical parameters can be found in the text or in the
Supporting Information. Right: NBO plots of the (a) Sb‒Au and (b) O‒Sb major bonding interactions in [3]2 (isodensity value 0.05). Hydrogen atoms are omitted.
+
phosphine and phosphine oxide units resonate at 96.1 ppm and
4.3 ppm, respectively. The structure of [2b][Cl] is proposed to
be that depicted in Figure 2, based on the similarity of the
bipyramidal with the gold atom and the oxygen atom of the
phosphine oxide occupying the apical sites. A further indicator of
this coordination geometry comes from the sum of C‒Sb‒C
angles which approaches the ideal value of 360° in both
structures (Σ(C‒Sb‒C) = 356.1(4) for [2a][Cl] and 356.7(4)° for
4
2 6 4 2 3
phosphine chemical shift with that of ((o-(Ph P)C H ) SbCl )AuCl
5a]
(
79.2 ppm).[ To confirm that these two isomers differ in the way
they interact with the chloride counterions, we treated
[3][NTf
166.25(9)° for [3][NTf
2 2
176.39(6)° for [3][NTf ]
2
]
2
). The values of the P‒Au‒P (167.30(9) for [2a][Cl] and
) and Cl‒Au‒Sb (172.79(6) for [2a][Cl] and
) angles indicates that the four primary
3
1
[
2a][Cl]/[2b][Cl] with 2 equivalents of AgNTf
spectroscopy indicated the emergence of a new species,
3][NTf , characterized by a single set of resonances at 68.7 ppm
2
.
In situ P NMR
2 2
]
[
2
]
2
ligands bound to gold are arranged in a square planar geometry,
with the chloride ligand (Cl1) positioned trans from the antimony
atom. This square planar geometry is consistent with the strong
donation of a gold d-orbital electron pair to antimony, leading to
an electronic configuration that approaches that of a classical d8
metal center. In the case of [2a][Cl], the square planar gold atom
is capped by a chloride ligand that forms a long Au‒Cl interaction
of 2.910(2) Å. A Natural Bond Orbital (NBO) analysis of [3]2+
affords a bonding description in which a dicationic triarylantimony
unit is stabilized intramolecularly by donation from the phosphine
oxide functionality and from the metallobasic gold atom. Indeed,
and 42.3 ppm (2:1 integration ratio).
the NBO method describes the Sb‒O interaction as
a
lp(O)p(Sb) donor acceptor interaction which contributes to the
stability of the complex by E( = 69.7 kcal/mol. The Sb-Au linkage
2)
2
is also donor acceptor in character and involves
a
d
x
-
2
2
y
z
(Au)p(Sb) and a d (Au)p(Sb) interactions which stabilize
(2)
the complex by
E
= 39.3 kcal/mol and 10.5 kcal/mol,
respectively. Taken together, the second order perturbation
energies suggest that the dative bonds formed by the two donors
have a similar strength. This bonding description supports the
formulation of complex [3]2 as a stibonium dication stabilized
intramolecularly by two Lewis bases.
2 2
Scheme 1. Synthesis of [2a][Cl] and [3][NTf ]
+
The structures of [2a][Cl] and [3][NTf
2 2
] have been established in
the solid-state.[12] The Au–Sb bond distances of 2.613(7) Å in
[
2a][Cl] and 2.6269(7) Å in [3][NTf are significantly shorter than
2 2
]
With the view of activating the gold center,[5a] we treated [3]2+ with
in 1 (2.709(9) Å) thus indicating a strengthening of the Au‒Sb
interaction triggered by the increased Lewis acidity of the
antimony center. In accordance with the bonding situation
depicted for model complex VI, the coordination geometry of the
antimony center in both complexes is distorted trigonal
an additional equivalent of AgNTf
31P
NMR spectroscopy showed the emergence two new
resonances at 67.9 ppm and 49.1 ppm (2:1 intensity) which we
assign to the formation of [4][NTf , a complex in which the gold-
2
in dichloromethane (Figure 3).
2 2
]
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bound chloride anion is replaced by a triflimide anion. Formation
Next, we decided to test whether this catalyst could also promote
of [4][NTf
2
]
2
is however partial and only reaches 55% conversion
. The stability of the Au-
hydroamination reactions. The reaction of styrene and p-
toluenesulfonamide (TsNH ) afforded the Markovnikov product
2
after addition of 7 equivalents of AgNTf
2
Cl bond of [3]2+ is assigned to the dicationic nature of the complex
and its reluctance to acquire a greater positive character by
replacement of the chloride by a more weakly coordinating
triflimide counteranion. We note that the phosphine oxide
resonance of [3]2+ undergoes a small but noticeable upfield shift
which might be explained by a change in the polarity of the
which was obtained in high yield after 6 h (Scheme 2; Table 1,
entry 1). Given the stoichiometry of the chloride abstraction
2
+
reaction (Figure 3), we decided to vary the [3] /AgNTf
1/1 to 1/7 (entries 2-4). NMR monitoring indicates that additional
equivalents of AgNTf results in a higher yield of the product after
2
ratio from
2
the first hour. This result suggests that the putative triflimide
complex acts as a catalyst, presumbaly via the electrophilic
mechanism shown in Scheme 3.
2
medium as an excess of AgNTf is added to the solution.
2
Table 1. Hydroamination of styrene and substituted styrenes by TsNH .
Entry
precatalyst X
m[a]
1
T (C) Time Yield [b]
Product
5a
1
2
3
4
5
6
7
8
9
[3][NTf
[3][NTf
[3][NTf
[3][NTf
[2][Cl]
[2][Cl]
[2][Cl]
[2][Cl]
[3][NTf
[3][NTf
[3][NTf
2
2
2
2
]
]
]
]
H
H
H
H
H
H
H
H
F
35
35
35
35
35
35
35
35
35
35
25
6 h
1 h
1 h
1 h
6 h
1 h
1 h
1 h
6 h
6 h
94%
20%
29%
44%
93%
19%
29%
46%
96%
42%
1
5a
4
5a
7
5a
3
5a
3
5a
6
5a
9
5a
2
]
2
]
2
]
1
5b
2 2
Figure 3. Chloride abstraction from [3][NTf ] by addition of equivalents of
1
0
1
Cl
Me
1
5c
AgNTf . The resonances marked by a blue dot correspond to the [4][NTf ] .
2
2 2
1
1
20 min 32%
5d
[
a] m refers to the number of equivalents of AgNTf
2
. [b] The yield was measured
Given the weakly coordinating nature of the triflimide anion and
its extensive use as a counteranion in gold mediated catalysis,[13]
1
by H NMR spectroscopy using 1,2-dichloroethane as an internal standard
we became eager to test the catalytic properties of [4][NTf
When [4][NTf was generated in situ by addition of 3 equivalents
of AgNTf to [2][Cl], we observed rapid styrene polymerization
Scheme 2).[14] The emergence of such a reactivity for a
bis(phosphine)gold moiety such as that in [4][NTf is surprising
and reflective of the reactivity enhancement achieved in the
polycationic gold complex. A parallel can be drawn between this
finding and the reactivity enhancement sometimes observed
when cationic L-type ligands are coordinated to late transition
metals.[15]
2
2
] .
We were also eager to test whether [4][NTf
in situ, starting from [2][Cl]. We found that when generated in this
way, [4][NTf showed a catalytic activity in the hydroamination of
styrene that is almost identical to that obsvered when [3][NTf is
used as a pre-catalyst (entries 5-8). This reaction is not activated
by complex [3]2+ or AgNTf
alone. When 5 mol% HNTf was
employed as a catalyst, only 16% of hydroamination product was
formed, and formation of polystyrene was observed. This poor
selectivity adds credence to the involvement of the gold-antimony
2 2
] could be generated
2 2
]
2 2
]
2
(
2 2
]
2 2
]
2
2
complex as the active species. Complex [4][NTf
significantly more active than other gold-based catalysts such as
Ph PAuCl/AgOTf or (PhO)
PAuCl/AgOTf.[16] These two catalysts
2 2
] appears
3
3
also promote the reaction of styrene with p-toluenesulfonamide
but necessitate high temperatures (85C) and extended reaction
times (14 h) to afford the hydroamination product in only moderate
yields (50-60%).
hydroaminated, a results expected based on the similar Hammet
parameters[17] of hydrogen (
= 0) and fluorine ( = 0.06) (entry
). Reaction of the more electron-poor 4-chlorostyrene ( = 0.23)
is distinctly slower in agreement with the proposed electrophilic
mechanism (entry 10). Further support for this electrophilic
mechanism is provided by the behavior of 4-methylstyrene which
is fully consumed after 20 mins at room temperature. In this case,
4-Fluorostyrene is also efficiently
p
p
Scheme 2. Hydroamination of styrene catalyzed by [3]2+/ AgNTf
and
2
9
p
+
polymerization of styrene catalyzed by or [2] / 3 AgNTf
2
.
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however, only about 32% of the hydroamination product is formed
along with unidentified products and oligomers (entry 11).
Devillard, G. Bouhadir, D. Bourissou, Angew. Chem. Int. Ed. 2015, 54,
730-732; Angew. Chem. 2015, 127, 740-742; l) B. R. Barnett, C. E.
Moore, P. Chandrasekaran, S. Sproules, A. L. Rheingold, S. DeBeer, J.
S. Figueroa, Chem. Sci. 2015, 6, 7169-7178; m) G. Bouhadir, D.
Bourissou, Chem. Soc. Rev. 2016, 45, 1065-1079; n) G. Bouhadir, D.
Bourissou, in The Chemical Bond III (Ed.: D. M. P. Mingos), 2017, 141-
201.
[
2]
a) W. H. Harman, J. C. Peters, J. Am. Chem. Soc. 2012, 134, 5080-5082;
b) J. S. Anderson, J. Rittle, J. C. Peters, Nature 2013, 501, 84-87; c) F.
Inagaki, C. Matsumoto, Y. Okada, N. Maruyama, C. Mukai, Angew.
Chem. Int. Ed. 2015, 54, 818-822; Angew. Chem. 2015, 127, 832-836;
d) T. Schindler, M. Lux, M. Peters, L. T. Scharf, H. Osseili, L. Maron, M.
E. Tauchert, Organometallics 2015, 34, 1978-1984; e) F. Inagaki, K.
Nakazawa, K. Maeda, T. Koseki, C. Mukai, Organometallics 2017, 36,
3005-3008; f) P. Steinhoff, M. Paul, J. P. Schroers, M. E. Tauchert,
Dalton Trans. 2019, 48, 1017-1022.
Figure 4. Proposed mechanism for hydroamination catalyzed by [4]2+
.
[
3]
a) R. C. Cammarota, L. J. Clouston, C. C. Lu, Coord. Chem. Rev. 2017,
3
34, 100-111; b) B. L. Ramirez, P. Sharma, R. J. Eisenhart, L. Gagliardi,
In conclusion, we describe the synthesis and characterization of
a gold chloride complex, [3][NTf , featuring a dicationic Z-type
antimony ligand. Formation of this complex is made possible by
the coordination of a neutral phosphine oxide donor that
attenuates the reactivity of the dicationic antimony center.
Despite its electron-deficient nature, the gold center of [3]2+ can
C. C. Lu, Chem. Sci. 2019, 10, 3375-3384.
2 2
]
[
4]
5]
R. C. Cammarota, C. C. Lu, J. Am. Chem. Soc. 2015, 137, 12486-12489.
[
̈
a) H. Yang, F. P. Gabbaı, J. Am. Chem. Soc. 2015, 137, 13425-13432;
b) S. Sen, I.-S. Ke, F. P. Gabbaï, Organometallics 2017, 36, 4224-4230.
a) T. W. Hudnall, C.-W. Chiu, F. P. Gabbaï, Acc. Chem. Res. 2009, 42,
388-397; b) J. M. Bayne, D. W. Stephan, Chem. Soc. Rev. 2016, 45, 765-
[6]
[7]
7
74.
C. R. Wade, I.-S. Ke, F. P. Gabbaï, Angew. Chem. Int. Ed. 2012, 51, 478-
81; Angew. Chem. 2012, 124, 493-496.
D. You, H. Yang, S. Sen, F. P. Gabbaï, J. Am. Chem. Soc. 2018, 140,
644-9651.
be activated by conversion into the proposed triflimide complex
2
+
[
4] . Generation of this complex is accompanied by the
4
[
18]
emergence of atypical reactivity toward styrene which is readily
polymerized or converted into the hydroamination Markovnikov
product when in the presence of p-toluenesulfonamide. These
unusual reactions highlight the unique activation resulting from
the coordination of the dicationic antimony Z-type ligand to the
gold center.
[
[
8]
9]
9
S. S. Chitnis, H. A. Sparkes, V. T. Annibale, N. E. Pridmore, A. M. Oliver,
I. Manners, Angew. Chem. Int. Ed. 2017, 56, 9536-9540; Angew. Chem.
2017, 129, 9664-9668.
[
10] a) A. P. M. Robertson, N. Burford, R. McDonald, M. J. Ferguson, Angew.
Chem. Int. Ed. 2014, 53, 3480-3483; Angew. Chem. 2014, 126, 3548-
3551; b) A. P. M. Robertson, S. S. Chitnis, H. A. Jenkins, R. McDonald,
M. J. Ferguson, N. Burford, Chem. Eur. J. 2015, 21, 7902-7913.
11] C. R. Wade, F. P. Gabbaï, Angew. Chem. Int. Ed. 2011, 50, 7369-7372;
Angew. Chem., 2011, 123, 7507-7510.
Acknowledgments
[
[
2 2
12] CCDC 1905863 ([2a][Cl]) and 1905864 ([3][NTf ] ) contain the
This work was supported by the National Science Foundation
supplementary crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
(
CHE-1566474), the Welch Foundation (A-1423), and Texas A&M
University (Arthur E. Martell Chair of Chemistry).
[
13] a) M. Jia, M. Bandini, ACS Catalysis 2015, 5, 1638-1652; b) N. Mézailles,
L. Ricard, F. Gagosz, Org. Lett. 2005, 7, 4133-4136.
Conflict of interest
[14] a) M. Emre Hanhan, Gold Bull. 2011, 44, 43-47; b) M. A. Cinellu, L.
Maiore, G. Minghetti, F. Cocco, S. Stoccoro, A. Zucca, M. Manassero, C.
Manassero, Organometallics 2009, 28, 7015-7024; c) A. S. K. Hashmi,
S. Schäfer, V. Göker, C. D. Eisenbach, K. Dirnberger, Z. Zhao-Karger, P.
Crewdson, Aust. J. Chem. 2014, 67, 500-506; d) J. Urbano, A. J.
Hormigo, P. de Frémont, S. P. Nolan, M. M. Díaz-Requejo, P. J. Pérez,
Chem. Commun. 2008, 759-761.
The authors declare no conflictof interest.
Keywords: antimony • gold • ligand design • olefin •
hydroamination
[
[
[
15] a) M. Alcarazo, Acc. Chem. Res. 2016, 49, 1797-1805; b) J. W. Dube, Y.
Zheng, W. Thiel, M. Alcarazo, J. Am. Chem. Soc. 2016, 138, 6869-6877.
16] a) J. Zhang, C.-G. Yang, C. He, J. Am. Chem. Soc. 2006, 128, 1798-
References
1799; b) X. Giner, C. Nájera, Org. Lett. 2008, 10, 2919-2922.
17] a) L. P. Hammett, J. Am. Chem. Soc. 1937, 59, 96-103; b) C. Hansch, A.
Leo, R. W. Taft, Chem. Rev. 1991, 91, 165-195.
[
1]
a) D. F. Shriver, Acc. Chem. Res. 1970, 3, 231-238; b) G. Parkin,
Organometallics 2006, 25, 4744-4747; c) A. F. Hill, Organometallics
[18] a) C.-Y. Wu, T. Horibe, C. B. Jacobsen, F. D. Toste, Nature 2015, 517,
449-454; b) B. R. Reiner, M. W. Bezpalko, B. M. Foxman, C. R. Wade,
Organometallics 2016, 35, 2830-2835.
2006, 25, 4741-4743; d) G. Bouhadir, A. Amgoune, D. Bourissou, Adv.
Organomet. Chem. 2010, 58, 1-107; e) A. Amgoune, D. Bourissou,
Chem. Commun. 2011, 47, 859-871; f) H. Braunschweig, R. D. Dewhurst,
Dalton Trans. 2011, 40, 549-558; g) G. R. Owen, Chem. Soc. Rev. 2012,
41, 3535-3546; h) H. Kameo, H. Nakazawa, Chem. Asian J. 2013, 8,
1720-1734; i) J. S. Jones, F. P. Gabbaï, Acc. Chem. Res. 2016, 49, 857-
867; j) J. S. Jones, F. P. Gabbaï, Chem. Lett. 2016, 45, 376-384; k) M.
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COMMUNICATION
.
COMMUNICATION
Ying-Hao Lo, François P. Gabbaï
Page No. – Page No.
An antimony(V) dication as a Z-type
ligand: Turning on styrene activation
at gold
Very positive is the influence played by a doubly charged antimony Z-type ligand
on the electrophilic properties of the corresponding gold complex. The accentuated
-accepting properties of this new antimony ligand impart atypical reactivity to the
gold center which readily promotes the polymerization and hydroamination of
styrene.
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