Carbon-sulfur bond formation by reductive elimination of gold(iii) thiolates

Article abstract of DOI:10.1039/c8dt00906f

Whereas the reaction of the gold(iii) pincer complex (C^N^C)AuCl with 1-adamantyl thiol (AdSH) in the presence of base affords (C^N^C)AuSAd, the same reaction in the absence of base leads to formation of aryl thioethers as the products of reductive elimin

Full text of DOI:10.1039/c8dt00906f

View Article Online
View Journal
Dalton
Transactions
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: L. Currie, L.
Rocchigiani, D. L. Hughes and M. Bochmann, Dalton Trans., 2018, DOI: 10.1039/C8DT00906F.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Volume 45 Number
1 7 January 2016 Pages 1–398
Dalton
Transactions
Accepted Manuscripts are published online shortly after
An international journal of inorganic chemistry
www.rsc.org/dalton
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1477-9226
PAPER
Joseph T. Hupp, Omar K. Farha et al.
Efficient extraction of sulfate from water using
framework
a Zr-metal–organic
rsc.li/dalton

Page 1 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
1
Carbon-sulfur bond formation by reductive elimination of gold(III) thiolates†
Lucy Currie, Luca Rocchigiani, David L. Hughes and Manfred Bochmann*
School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK
Abstract
Whereas the reaction of the gold(III) pincer complex (C^N^C)AuCl with 1-adamantyl thiol (AdSH) in the
presence of base affords (C^N^C)AuSAd, the same reaction in in the absence of base leads to formation
of aryl thioethers as the products of reductive elimination of the Au-C and Au-S ligands (C^N^C =
dianion of 2-6-diphenylpyridine or 2-6-diphenylpyrazine). Although high chemical stability is usually
taken as a characteristic of pincer complexes, results show that thiols are capable of cleaving one of the
pincer Au-C bonds. This reaction is not simply a function of S-H acidity, since no cleavage takes place
with other more acidic X-H compounds, such as carbazole, amides, phenols and malonates. The reductive
C-S elimination follows a second-order rate law, -d[1a]/dt = k[1a][AdSH]. Reductive elimination is
enabled by displacement of the N-donor by thiol; this provides the conformational flexibility necessary
for C-S bond formation to occur. Alternatively, reductive C-S bond formation can be induced by reaction
of pre-formed thiolates (C^N^C)AuSR with a strong Brønsted acid, followed by addition of SMe2 as
base. On the other hand, treatment of (C^N^C)AuR (R = Me, aryl, alkynyl) with thiols under similar
conditions leads to selective C-C rather than C-S bond formation. The reaction of (C^N^C)AuSAd with
H+ in the absence of a donor ligand affords the thiolato-bridged complex [{(C^N-CH)Au(μ-SAd)}2]2+
which was crystallographically characterised.
Introduction
Reductive elimination is a common product-forming step in many homogeneously catalyzed
reactions. In the chemistry of gold complexes this reaction has been extensively studied as a means of C-
C bond formation.1,2 Reductive elimination leading to carbon-heteroatom bonds are comparatively rare
but have also been observed, such as the formation of C(sp3)-X and C(sp2)-X carbon-halide bonds,3-5 as
well as C(sp2)-E bonds through reactions with P-,6 O- and N-nucleophiles7 including phosphine ligands,
via three-coordinate intermediates (Scheme 1 A - E). The formation of C-S bonds by reductive
elimination of metal thiolates has been studied extensively for palladium8,9 and has also been observed for
rhodium pincer complexes10 and applied to the rhodium-catalysed formation of diaryl thioethers.11 By

Dalton Transactions
Page 2 of 22
View Article Online
DOI: 10.1039/C8DT00906F
2
contrast, we are aware of only one example for C-S bond formation involving gold(III), the reaction of
cyclometallated gold(III) C^N chelate complexes with –SH containing peptides, which allowed the
transfer of the C^N moiety to the peptide via C-S linkages (Scheme 1 F).12 Reductive S-S elimination
from Au(III) thiolates has also been observed.13
We have recently reported the synthesis, aggregation behaviour and photoluminescence of a series of
gold(III) thiolates stabilized by cyclometallated C^N^C 2-6-diphenylpyridine and 2-6-diphenylpyrazine
pincer ligands.14 Apart from a general interest in C^N^C-type pincer ligands to prevent reductive
processes in gold(III) compounds15 and as a means to supporting highly reactive gold(III) species,16 the
origin of this work on thiolates was the fact that gold carbene complexes supported by such pincer ligands
show interesting anti-cancer activities.17,18. In cancer cells such compounds are frequently rendered
harmless by reduction by the –SH containing tripeptide glutathione, which tends to be overexpressed and
acts as a reducing defence mechanism. However, our [C^N^C)Au(NHC)]+ compounds reacted with
glutathione only very slowly, which may in part explain their high cytotoxicity.17 This behaviour contrasts
with that of N^N^N pincer ligands, which were found to be reduced by thiols very easily, with loss of the
pincer ligand.19 We therefore wished to explore which reaction pathways might be open to our C^N^C
pincer-stabilised gold complexes on reaction with thiols. We show here that, unlike other mildly acidic
protic reagents, alkyl thiols are capable of cleaving cyclometallated Au-C bonds, which leads to formation
of aryl thioethers through reductive elimination of the thiolato and pincer ligands.

Page 3 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
3
Scheme 1. Formation of C-heteroatom bonds by reductive elimination from gold(III) precursors.3,4,6,7,12
Results and Discussion
C-S bond formation. As previously reported,14a the reaction of (C^N^C)AuCl (1a,b) with 1-
adamantyl thiol (AdSH) in the presence of base affords the corresponding thiolate 2a,b. We were
therefore surprised to find that the addition of thiols in the absence of base leads to formation of aryl
thioethers as the products of reductive elimination (Scheme 2).

Dalton Transactions
Page 4 of 22
View Article Online
DOI: 10.1039/C8DT00906F
4
Scheme 2
For complete reductive elimination two molar equivalents of AdSH are required; with one equivalent
the reaction remains incomplete and gives a mixture of starting material and 3. Complete conversion to
3a, b was achieved only after addition of further thiol. The reductive elimination product was identified
by NMR spectroscopy and mass spectrometry. The gold(I) by-product, formulated as [AuCl(AdSH)]x, is
formed as an aggregate according to diffusion NMR measurements (see ESI).
Although AdSH cleaves one of the Au-C bonds, the reductive elimination process is not related
simply to the acidity of thiols. For example, no reaction was observed between 1a and other more acidic
X-H compounds, such as carbazole, amides, phenols and malonates, even over extended periods of time.
Monitoring mixtures of AdSH with 1a by NMR spectroscopy indicated that the reaction follows a
second-order rate law, -d[1a]/dt = k[1a][AdSH], for [AdSH] = 0.04 – 0.4 M. The rate depends linearly on
[AdSH], which implies that one equivalent of thiol and 1a are required in the rate determining step (Fig.
1). The reaction rate is unaffected by air and water. No intermediates were observed at low [AdSH] while,
when a large molar excess of thiol was used, the formation of the gold(III) thiolate 2a was detected during
the initial phase of the reaction, before it was consumed over a period of time (Fig.2).
The observation of 2a at the beginning of the reaction implies that 1 equivalent of HCl is released
upon ligand exchange. This could potentially induce protodeauration of 2a and open the path for C–S
reductive elimination. As control experiment, isolated 2a was treated with 1 molar equivalent of HCl.

Page 5 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
5
However, this reaction led to the instantaneous regeneration of the chloride 1a, together with the release
of AdSH. The mixture then evolved as described before, to give 3a in 50% yield. It can be assumed
therefore that a reversible chloride/thiolate exchange takes place, which explains why 2a is observed at
high [AdSH] before reduction occurs. Furthermore, the possibility that AdSH is directly involved in Au-C
bond cleavage cannot a priori be excluded. To check this hypothesis, we reacted the thiolato complex 2a
with 30 equivalents of AdSH. Interestingly, we observed again reductive elimination to 3a, suggesting
that AdSH induces Au–C bond breakage. However, thiol-induced reductive elimination starting from the
pre-formed thiolate complex 2a proceeds very much more slowly (80% conversion after 2.5 weeks) than
reductive elimination from the chloride 1a under otherwise identical conditions (complete reaction within
3 hours). It seems reasonable therefore to assume that protodeauration of 1a gives the bidentate
intermediate 4a, which can undergo pyridine substitution by a further equivalent of AdSH generating 5a.
Neither 4a nor 5a could be spectroscopically detected and must therefore be consumed rapidly. Since the
aryl ligand in 5a is no longer a chelate but is conformationally flexible, fast reductive elimination is now
enabled (Scheme 3).
Scheme 3. Reductive C-S elimination pathway induced by thiols.
The thiol-induced reductive elimination of the pyrazine complex 1b proceeds at comparable rates
(Fig. 1), suggesting that displacement of the N-donor is not rate-limiting. Overall, the reaction sequence is
reminiscent of the reductive aryl-aryl coupling process proposed by Vicente et al. for the reaction of bis-
aryl gold(III) complexes (C^N)Au(aryl)Cl with phosphines.20

Dalton Transactions
Page 6 of 22
View Article Online
DOI: 10.1039/C8DT00906F
6
Fig. 1. Dependence of the rate of consumption of 1a (left) and 1b (right) on the thiol concentration
(CD2Cl2, 25 °C).
Fig. 2. Product distribution of the reaction of 1a with AdSH as a function of time (CD2Cl2, 25 °C).
Given that the process shown in Scheme 3 requires both an acid and a sulfur-donor, it should be
possible to achieve the same reductive elimination using an alternative acid with a non-coordinating
anion, coupled with an alternative S-donor such as dimethylsulfide. This possibility was tested using 2a
as starting material. We have shown before that the addition of the strong Brønsted acid [H(OEt2)2]+-
[H2N{B(C6F5)3}2]21 (“HAB2”) to C^N^C pincer complexes leads to protolytic cleavage of one of the Au-
C bonds.22 Treatment of 2a with HAB2 followed by the addition of SMe2 does indeed lead to the clean

Page 7 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
7
formation of 3a, together with [Au(SMe2)2]+.23 The reaction rate increased with increasing SMe2
concentration (Scheme 4).
Scheme 4. Reductive C-S elimination induced by a proton / SMe2 combination.
Monitoring the reaction of HAB2 with 2a in the absence of SMe2 or base by 1H NMR spectroscopy
showed a series of intermediates and slow changes over a period of over 2 weeks, connected with Au-C
bond cleavage and reversible diethyl ether coordination. Interestingly, under these conditions, i.e. in the
absence of an S-donor, no reductive elimination takes place. The final spectrum showed only
uncoordinated ether, together with the thiolato-bridged complex 6 (Scheme 5). This product gave no
indication for proton shuttling.
Scheme 5. Synthesis of 6.
Complex 6 was isolated as yellow crystals. The structure was confirmed by X-ray diffraction (Fig.
3). The crystal structure showed two metal centres linked by bridging thiolates. The unit cell contains a
dimeric cation (lying about a centre of symmetry) and two [NH2{B(C6F5)3}2]- anions. Each gold atom is
supported by a cyclometallated 2-phenylpyridine ligand, with the protodeaurated dangling phenyl ring
rotated ca 51.3(4)° about the C(16)–C(161) bond away from the Au atom, so that C(162) is far removed

Dalton Transactions
Page 8 of 22
View Article Online
DOI: 10.1039/C8DT00906F
8
from the coordinating site, now occupied by one of the bridging S atoms. The gold atom has an
approximately square planar, fourfold coordination pattern, bonding to the pyridine N-atom, the ortho-
carbon atom of one of its phenyl substituents, and the bridging sulfur atoms of the two S-adamantyl
ligands. The two adamantyl substituents are mutually trans. The sterically congested ligand sphere leads
to distortions of the gold coordination geometry, e.g. the trans C(122)-Au-S(1)#1 angle is reduced from
the expected 180° to 163.4(3)°. The bridging Au–S bonds are quite different in length, with the one trans
to the pyridine N-atom being 0.15 Å shorter than the bond trans to the phenyl C-atom. The adamantyl
groups are positioned almost perpendicular to the central Au2S2 plane, with Au–S(1)–C(1) angles of
103.2(3) and 98.9(3) °.
Fig. 3. Side and (partial) top view of the cation in 6. Left: H atoms, tert.-butyl groups and anions are
omitted for clarity. Ellipsoids are drawn at 50%. Selected bond distances [Å] and angles [°]:Au-C(122)
2.066(8), Au-N(11) 2.108(7), Au-S(1) 2.323(2), Au-S(1)#1 2.469(2), S(1)-C(1) 1.880(9); C(122)-Au-
N(11) 81.2(3), C(122)-Au-S(1) 94.3(3), N(11)-Au-S(1) 174.4(2), C(122)-Au-S(1)#1 163.4(3), N(11)-Au-
S(1)#1 101.2(2), S(1)-Au-S(1)#1 84.02(8).
C-C and attempted C-E bond formation. Under the same experimental conditions, and following
similar mechanistic principles, the gold(III) methyl and aryl complexes 7 and 8, respectively, react with
excess AdSH to give selective C–C bond formation, generating the corresponding coupling products 10 –
11 (Scheme 6). The reaction is selective for C-C rather than C-S reductive elimination. The process is
however slow, and at 25 C requires 6 days for quantitative aryl-aryl coupling, while aryl-methyl
coupling is even slower (complete in 24 days). In the presence of a large excess of thiol C-C coupling of

Page 9 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
9
the alkynyl complex 9 is also observed, over a period of months, to give 12. The trend in the rates of C-C
bond formation under these conditions therefore follows the order aryl-aryl > aryl-methyl >> aryl-
alkynyl.
Scheme 6. Thiol-triggered reductive elimination of C(sp2)-C(sp3), C(sp2)-C(sp2) and C(sp2)-C(sp) bonds.
The HAB2/SMe2 protocol was extended to other heteroatom species in an effort to induce C-E bond
formation for heteroatoms other than sulfur. However, rather different reactivity patterns were observed.
For example, addition of HAB2 to the phenolate 1324 gave the ether complex 14, without Au-C cleavage.
On the other hand, addition of HAB2 to the carbazolato complex 15 gave the protodeaurated species 16,
which demonstrates that given the low basicity of the carbazolate-N atom, the Au-C bond is the preferred
site of proton attack. The NOE spectrum of 16 showed that the complex underwent ether-mediated proton
shuttling between the two Au-C bonds at a rate of 1.23 s-1, similar to the reversible protodeauration
previously observed for 1/HAB2 but slightly faster.22 However, addition of SMe2 to solutions of 16 leads
to protolytic cleavage of the carbazole ligand, without C-N bond formation, and the Au-C bond of the
pincer ligand is regenerated to give 17 (Scheme 7).

Dalton Transactions
Page 10 of 22
View Article Online
DOI: 10.1039/C8DT00906F
10
Scheme 7. Reactions of gold(III) phenolates and carbazolates with H+/SMe2.
Conclusion.
The reaction of (C^N^C)Au(III) pincer complexes has rather unexpectedly shown that thiols are
capable of cleaving one of the pincer Au-C bonds, followed by a reductive elimination process and
formation of aryl thioethers. The reaction follows second-order kinetics. Displacement of the N-donor is
required to access an intermediate with the conformational flexibility necessary to initiate the C···S bond
forming step. Au-C cleavage with thiols proceeds independently of thiol acidity, since there is no reaction
with other acidic reagents. The reaction sheds light on the likely fate of (C^N^C)Au-based cytotoxic
reagents under physiological conditions, such as in the presence of glutathione. With other gold starting
materials (C^N^C)AuR (R = Me, aryl or alkynyl), the same thiol-treatment protocol leads to selective C-
C rather than C-S bond formation, with rates decreasing in the order R = aryl > Me >> alkynyl.
Experimental
General Considerations. When specified, manipulations were performed by using standard Schlenk
line techniques under dry N2 or in a MBraun Unilab glovebox with a high capacity recirculator (<1.0 ppm

Page 11 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
11
O2 and H2O). All solvents were dried by means of the appropriate drying agent and distilled. CD2Cl2 was
stored in the glovebox over activated 4 Å molecular sieves. (C^Npy^C)AuCl (1a),25 (C^Npz^C)AuCl
(1b),14b (C^N^C)AuMe (7),26 (C^N^C)Au(p–C6H4F) (8),26 (C^N^C)AuOC6H5 (10),24 [AgC≡CC6H4-3-
OMe]n27 and [H(OEt2)2][H2N(B(C6F5)3)2] (HAB2)21 were synthesized according to literature procedures.
1H, 1H PGSE, 19F, 13C{1H}, 1H NOESY, 1H,13C HMQC and 1H,13C HMBC NMR experiments were
recorded on a Bruker DPX–300 spectrometer equipped with a 1H,BB smartprobe and Z-gradients. 1H
NMR spectra are referenced to the residual protons of the deuterated solvent. 13C NMR spectra are
referenced to the D-coupled 13C signals of the solvent.
Synthesis and characterisation
Under a N2 atmosphere, (C^Npy^C)AuCl 1a (40.0 mg, 0.070 mmol) and potassium t-butoxide (9.4
mg, 0.084 mmol), were suspended in 5 mL of dry toluene in a Schlenk tube and stirred for 3 h. 1-
Adamantanethiol (11.7 mg, 0.070 mmol) was added and reaction was stirred for a further 3 h. The solvent
was removed under vacuum to give a solid with was dissolved in dichloromethane in air and passed
through a Celite plug. The solution was evaporated to dryness and washed with light petroleum to give 2a
as a bright yellow solid (45 mg, 0.059 mmol, 91 %). 1H NMR (CD2Cl2, 300.13 MHz, 298 K): δ 8.46 (d,
4JH-H = 2.0 Hz, 2 H, H8), 7.83 (t, 3JH-H = 8.0 Hz, 1 H, H1), 7.54 (d, 3JH-H = 8.1 Hz, 2 H, H5), 7.47 (d, 3JH-H
8.0 Hz, 2 H, H2), 7.27 (dd, 3JH-H = 8.1 Hz, 4JH-H = 2.0 Hz, 2 H, H6), 2.14 (bd, 3JH-H = 2.4 Hz, 6 H, H11),
=
1.92 (bs, 3 H, H12), 1.61 (s, 6 H, H13), 1.39 (s, 18 H, tBu). 13C{1H} NMR (CD2Cl2, 75.48 MHz, 298 K): δ
171.6 (s, C4), 164.0 (s, C3), 154.8 (s, C7), 147.4 (s, C9), 142.6 (s, C1), 134.1 (s, C8), 125.0 (s, C5), 123.8 (s,
C6), 116.6 (s, C2), 50.2 (s, C11), 48.5 (s, C10), 36.7 (s, C13), 35.9 (s, C(CH3)3), 31.4 (s, C(CH3)3), 31.2 (s,
C12).

Dalton Transactions
Page 12 of 22
View Article Online
DOI: 10.1039/C8DT00906F
12
In situ synthesis. Under a N2 atmosphere, a J-Young NMR tube was charged with (C^Npy^C)AuCl
1a (5 mg, 0.0087 mmol) and AdSH (4.4 mg, 0.026 mmol) in CD2Cl2 (0.6 mL). The tube was sealed and
the reaction monitored by 1H NMR spectroscopy. Over the period of 3 hours, the reaction went to
completion and the fading of the yellow colour of (C^Npy^C)AuCl was observed to give a clear solution.
Bulk synthesis. Under a N2 atmosphere, a Schlenk tube was charged with 1a (0.030 g, 0.052 mmol)
and AdSH (0.018 g, 0.105 mmol), which were then dissolved in 5 mL of dry dichloromethane (5 mL).
The reaction was stirred at room temperature for 4 h until the solution turned from yellow to colourless.
The solvent was removed under vacuum, light petroleum (5 mL) was added and the suspension filtered.
The solvent was removed to give 3a as a white solid (0.025 g, 94 %). TOF MS ASAP+: m/z [3a+H]+
510.3194 (calc. 510.3195). The spectrum displays the expected isotopic pattern.1H NMR (CD2Cl2, 300.13
MHz, 298 K): δ 7.98 (d, 3JH-H = 8.4 Hz, 2 H, H5’), 7.76 (t, 3JH-H = 7.7 Hz, 1 H, H1), 7.68 (overlapped s, 1
H, H8), 7.67 (overlapped d, 1 H, H2’), 7.61 (d, 3JH-H = 8.0 Hz, 1 H, H5), 7.5 (m, 4 H, H6+6’+2), 1.86 (br s,
3H, H12), 1.57 (br d, 3JH-H = 1.4 Hz, 6 H, H11), 1.51 (m, 6 H, H13), 1.39 (s, 9 H, tBu), 1.36 (s, 9 H, tBu’).
13C{1H} NMR (CD2Cl2, 75.48 MHz, 298 K): δ 156.0 (s, C7’), 155.4 (s, C3), 154.5 (s, C7), 153.7 (s, C3’),
142.9 (s, C1), 137.5 (s, C8), 136.1 (s, C4), 131.5 (s, C5), 130.7 (s, C9), 130.0 (s, C5’), 128.8 (s, C4’), 127.6
(s, C2), 126.4 (s, C6+6’), 123.9 (s, C2’), 50.5 (s, C10), 44.0 (s, C11), 36.2 (s, C13), 35.4 (s, CMe3’), 35.2 (s,
CMe3), 31.3 (s, CMe3 + CMe3’), 30.5 (s, C12).

Page 13 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
13
To a J. Young NMR tube charged with (C^Npz^C)AuCl 1b (5 mg, 0.0087 mmol) in CD2Cl2 (0.6 mL)
was added AdSH (4.4 mg, 0.026 mmol). The tube was sealed and the reaction monitored by 1H NMR
over 3 h until the reaction was complete forming 3b (100% by NMR) and [ClAuSAd]nHn. Over the
course of the reaction the solution turned from bright yellow to a clear colourless solution. TOF MS
ASAP+: m/z [3b+H]+ 511.141 (calc. 511.3129). Spectrum displays the expected isotopic pattern. 1H
NMR (CD2Cl2, 300.13 MHz, 298 K): δ 8.91 (s, 1 H, H2), 8.89 (s, 1 H, H2’), 8.12 (d, 3JH-H = 8.6 Hz, 2 H,
H5’), 7.81 (d, 3JH-H = 8.1 Hz, 1 H, H5), 7.77 (d, 4JH-H = 1.8 Hz, 1 H, H8), 7.65 (partially overlapped dd, 3JH-H
= 8.1 Hz, 4JH-H = 1.8 Hz, 1 H, H6), 7.63 (d, 3JH-H = 8.6 Hz, 1 H, H6’), 1.86 (bs, 3 H, H12), 1.53 (d, 3JH-H = 1.8
Hz, 6 H, H11), 1.47 (m, 6 H, H13), 1.41 (s, 9 H, tBu), 1.38 (s, 9 H, tBu’). 13C{1H} NMR (CD2Cl2, 75.48
MHz, 298 K): δ 159.1 (s, C3/3’), 156.2 (s, C3/3’/7’), 156.1 (s, C3/3’/7’), 154.7 (s, C7), 138.9 (s, C4), 137.7 (s,
C8), 134.4 (s, C2), 131.5 (s, C4’), 131.1 (s, C5), 128.9 (s, C9), 127.8 (s, C2’), 127.4 (s, C5’), 127.3 (s, C6),
127.0 (s, C6’), 51.2 (s, C10), 43.9 (s, C11), 36.2 (s, C13), 35.4 (s, CMe3’), 35.2 (s, CMe3), 31.2 (s, CMe3 +
CMe3’), 30.5 (s, C12).
A J-Young’s NMR tube was charged with 2a (5 mg, 0.0071 mmol), HAB2 (8.4 mg, 0.0071 mmol)
and CD2Cl2 (0.6 mL). The reaction monitored by 1H NMR spectroscopy for 11 d until no further changes
were observed. Crystals of 6 suitable for X-ray crystallography were obtained from a CD2Cl2 solution. 1H
NMR (CD2Cl2, 300.13 MHz, 298 K): δ 8.33 (t, 3JH-H = 7.7 Hz, 1 H, H1), 8.05 (dd, 3JH-H = 8.0 Hz, 4JH-H
=
0.7 Hz, 1 H, H2), 7.80-7.50 (br m, 4 H, H5’+6’+8’+9’), 7.79 (dd, 3JH-H = 7.7 Hz, 4JH-H = 0.9 Hz, 1 H, H2’), 7.68
(d, 3JH-H = 8.3 Hz, 1 H, H5), 7.57 (dd, 3JH-H = 8.2 Hz, 4JH-H = 1.3 Hz, 1 H, H6), 7.00 (d, 4JH-H = 1.2 Hz, 1 H,
H8), 2.34 (d, 2JH-H = 11.2 Hz, 3 H, H11), 2.16 (br s, 3 H, H12), 2.08 (d, 2JH-H = 11.4 Hz, 3 H, H11), 1.78 (m,
3 H, H13), 1.58 (m, 3 H, H13), 1.40 (s, 9 H, tBu), 1.18 (s, 9 H, tBu’).
1H NMR (CD2Cl2, 300.13 MHz, 263 K): δ 8.33 (t, 3JH-H = 8.0 Hz, 1 H, H1), 8.04 (d, 3JH-H = 8.0 Hz, 1 H,
H2), 7.88 (d, 3JH-H = 7.8 Hz, 1 H, H9’), 7.78 (d, 3JH-H = 7.7 Hz, 1 H, H2’), 7.70 (d, 3JH-H = 8.2 Hz, 1 H, H8’),
7.67 (d, 3JH-H = 8.5 Hz, 1 H, H5), 7.55 (d, 3JH-H = 8.1 Hz, 1 H, H6), 7.47 (br s, 2 H, H5’+ 6’), 6.94 (s, 1 H,

Dalton Transactions
Page 14 of 22
View Article Online
DOI: 10.1039/C8DT00906F
14
H8), 2.31 (d, 2JH-H = 11.4 Hz, 3 H, H11), 2.14 (br s, 3 H, H12), 2.01 (d, 2JH-H = 10.9 Hz, 3 H, H11), 1.74 (d,
2JH-H = 14.9 Hz, 3 H, H13), 1.55 (d, 2JH-H = 14.9 Hz, 3 H, H13), 1.36 (s, 9 H, tBu), 1.14 (s, 9 H, tBu’ +Et2O
signal).
13C{1H} NMR (CD2Cl2, 75.48 MHz, 298 K): δ 162.8 (s, C3), 161.3 (s, C9), 160.5 (s, C3’), 157.8 (s, C7’),
-
157.3 (s, C7), 148.2 (brd, 1JC-F = 243.8 Hz, o-C-F H2N[B(C6F5)3]2 ), 144.8 (s, C1), 139.5 (brd, 1JC-F = 246.1
-
-
Hz, p-C-F H2N[B(C6F5)3]2 ), 139.3 (s, C4), 137.0 (brd, 1JC-F = 248.3 Hz, m-C-F H2N[B(C6F5)3]2 ), 135.3
(br s, CAnion), 134.4 (s, C4’), 129.2 (s, C6), 128.7 (s, C5), 128.3 (s, CAryl), 127.4 (s, CAryl), 127.0 (s, C2’),
125.9 (s, C8), 120.6 (s, C2), 69.9 (s, C2) 49.2 (s, C11), 37.0 (s, CMe3), 35.5 (s, CMe3’), 35.4 (s, C13), 31.7
(s, C12), 31.3 (s, CMe3), 30.1 (s, CMe3’).
Addition of dimethyl sulfide (4 μL, 0.0034 mmol) to a solution of 6 in a J-Young NMR tube gave
3a. Over the course of the 4 h the solution changed from yellow to colourless.
A flask was charged with 1a (40.0 mg, 0.070 mmol), [AgC≡CC6H4-3-OMe]n (50.2 mg, 0.210 mmol)
and dichloromethane (10 mL). The reaction was stirred in the dark for 21 d. The solution was filtered
through Celite and evaporated to dryness giving a solid which washed with light petroleum. The pure
product 9 was isolated as a light yellow powder (0.024 g, 51 %). 1H NMR (CD2Cl2, 300.13 MHz, 298 K):
δ 8.17 (d, 3JH-H = 2.0 Hz, 2 H, H8), 7.85 (t, 3JH-H = 8.0 Hz, 1 H, H1), 7.54 (d, 3JH-H = 8.2 Hz, 2 H, H5), 7.44
(d, 3JH-H = 8.0 Hz, 2 H, H2), 7.32 (dd, 3JH-H = 8.2 Hz, 4JH-H = 2.0 Hz, 2 H, H6), 7.26 (dd, 3JH-H = 8.0 Hz, 1 H,
H16), 7.19 (d psudu t, 3JH-H = 7.6 Hz, 4JH-H = 1.1 Hz, 1 H, H17), 7.14 (brm, 1 H, H13), 6.87 (ddd, 3JH-H = 8.0
Hz, 4JH-H = 2.4 Hz, 4JH-H = 1.1 Hz, 1 H, H15), 3.84 (s, 3 H, O-Me), 1.39 (s, 18 H, tBu). 13C{1H} NMR
(CD2Cl2, 75.48 MHz, 298 K): δ 167.3 (s, C9), 165.2 (s, C3), 159.8 (s, C14), 155.6 (s, C7), 147.0 (s, C4),
142.7 (s, C1), 133.7 (s, C8), 129.6 (s, C16), 128.1 (s, C12), 125.4 (s, C5), 124.7 (s, C17), 124.3 (s, C6), 116.8

Page 15 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
15
(s, C13), 116.7 (s, C2), 114.0 (s, C15), 101.4 (s, C11), 92.7 (s, C10), 55.5 (s, O-CH3) 35.7 (s, C(CH3)3), 31.3
(s, C(CH3)3).
[(C^N^C)AuEt2O][AB2] 14 was obtained as a transient species upon protodeauration of 5 mg of 13
with 9.1 mg of HAB2. 1H NMR (CD2Cl2, 300.13 MHz, 298 K): δ 7.96 (t, 3JH-H = 8.0 Hz, 1 H, H1), 7.56 (d,
3JH-H = 8.2 Hz, 2 H, H5), 7.47 (d, 4JH-H = 1.6 Hz, 1 H, H8), 7.44 (d, 3JH-H = 8.0 Hz, 2 H, H2), 7.43 (dd, 3JH-H
= 8.1 Hz, 4JH-H = 1.6 Hz, 2 H, H6), 7.93 (pst, 3JH-F/H-H = 8.0 Hz, 2 H, phenol H), 6.78 (m, 2 H, phenol H),
4.68 (q, 3JH-H = 7.0 Hz, 4 H, Et), 4.68 (t, 3JH-H = 7.0 Hz, 6 H, Et), 1.37 (s, 18 H, tBu).
Under an N2 atmosphere a flask was charged with 1a (0.050 g, 0.087 mmol), carbazole (0.015 g,
0.087 mmol) and KOBut (0.029 g, 0.26 mmol). Dry toluene (5 mL) was added and reaction was stirred at
60 °C for 16 h. The solution was filtered through Celite and evaporated to dryness, then washed with light
petroleum. The pure product 15 was isolated as a orange powder (0.036 g, 59.1 %). 1H NMR (CD2Cl2,
300.13 MHz, 298 K): δ 8.18 (d, 3JH-H = 7.4 Hz, 2 H, H14), 7.94 (t, 3JH-H = 8.0 Hz, 1 H, H1), 7.58 (d, 3JH-H
=
8.2 Hz, 2 H, H5), 7.53 (d, 3JH-H = 8.0 Hz, 2 H, H2), 7.49 (d, 3JH-H = 8.3 Hz, 2 H, H11), 7.25 (m, 4 H, H6+12),
7.11 (pseudo triplet, 3JH-H = 7.4 Hz, 2 H, H13), 6.93 (d, 4JH-H = 1.8 Hz, 2 H, H8), 0.96 (s, 18 H, tBu).
13C{1H} NMR (CD2Cl2, 75.48 MHz, 298 K): δ 168.5 (s, C4), 165.6 (s, C3), 155.4 (s, C7), 146.2 (s, C10),
146.2 (s, C9), 143.4 (s, C1), 133.1 (s, C8), 125.3 (s, C15), 125.2 (s, C5), 124.4 (s, C6/12), 124.3 (s, C6/12),
120.0 (s, C14), 117.2 (s, C13), 116.8 (s, C2), 35.2 (s, C(CH3)3), 30.8 (s, C(CH3)3).

Dalton Transactions
Page 16 of 22
View Article Online
DOI: 10.1039/C8DT00906F
16
16 was synthesised from 15 using the general procedure for protodeauration, starting from 5 mg of
15. The species decomposed over 3 h. 1H NMR (CD2Cl2, 300.13 MHz, 298 K): δ 8.21 (d, 3JH-H = 7.5 Hz,
2 H, H14), 7.98 (t, 3JH-H = 8.0 Hz, 1 H, H1), 7.90 (d, 3JH-H = 7.9 Hz, 2 H, H11), 7.76 (m, 3 H, H5+13), 7.60 (m,
5 H, H8+6+12+2), 7.41 (m, 3 H, H2’+5’), 7.12 (dd, 3JH-H = 8.2 Hz, 4JH-H = 1.8 Hz, 1 H, H6’), 5.62 (d, 4JH-H = 1.0
Hz, 1 H, H8’), 3.49 (brs, 12 H, CH2 (OEt2)), 1.17 (t, 3JH-H = 7.1 Hz, 18 H, CH3 (OEt2)), 1.41 (s, 9 H, tBu),
0.91 (s, 9 H, tBu’).
General procedure for reductive elimination investigations
Under a nitrogen atmosphere a J-Young NMR tube was charged with 5 mg of the desired gold
complex and 0.6 ml of CD2Cl2. An initial 1H NMR spectrum was acquired. 4.0 molar equivalents of
AdSH were added and the reaction was monitored by 1H NMR spectroscopy until formation of the
coupling product was complete.
Starting from 7, complete reductive elimination to 10 was observed after 24 days (yield 100% by NMR).
No side products were observed. 1H NMR (CD2Cl2, 300.13 MHz, 298 K): δ 8.02 (d, 3JH-H = 8.5 Hz, 2 H,
H5’), 7.81 (t, 3JH-H = 7.8 Hz, 1 H, H1), 7.70 (dd, 3JH-H = 7.9 Hz, 4JH-H = 0.9 Hz,1 H, H2/2’), 7.50 (d, 3JH-H
=
8.5 Hz, 2 H, H6’), 7.40 (d, 3JH-H = 7.8 Hz, 1 H, H5),7.33 (m, 3 H, H2/2’ + H6 + H8), 2.46 (s, 3 H, H10) , 1.37
(s, 9 H, tBu/ tBu’), 1.36 (s, 9 H, tBu/tBu’).

Page 17 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
17
Starting from 8, complete reductive elimination to 11 was observed after 6 days. Only the C-C coupling
product was observed (yield 100% by NMR). No side products were observed. 1H NMR (CD2Cl2, 300.13
MHz, 298 K): δ 7.79 (d, 3JH-H = 8.4 Hz, 2 H, H5’), 7.68 (d, 3JH-H = 8.1 Hz,1 H, H5), 7.56 (m, 2 H, H1 +
H2’), 7.53 (dd, 3JH-H = 8.1 Hz, 4JH-H = 1.9 Hz, 1 H, H6), 7.45 (m, 3 H, H6’ + H8), 7.45 (m, 2 H, H11), 6.96
(m, 3 H, H2 + H12), 1.40 (s, 9 H, tBu), 1.35 (s, 9 H, tBu’). 19F NMR (CD2Cl2, 282.36 MHz, 298K): δ -
117.2 (br, p–F).
The alkynyl complex 9 reacts slowly, giving 50 % conversion to 12 after 6 months. 1H NMR (CD2Cl2,
300.13 MHz, 298 K): δ 8.08 (d, 3JH-H = 8.5 Hz, 2 H, H5’), 7.85 (m, 3 H, H1 + H2 + H5), 7.75 (dd, 3JH-H
=
7.5 Hz, 4JH-H = 1.2 Hz, 1 H, H2’), 7.72 (d, 4JH-H = 1.8 Hz, 1 H, H8), 7.54 (dd, 3JH-H = 8.4 Hz, 4JH-H = 1.8 Hz,
1 H, H6), 7.48 (d, 3JH-H = 8.5 Hz, 2 H, H6’), 7.20 (pseudo t, 3JH-H = 7.9 Hz, 1 H, H16), 6.98 (d pseudo t, 3JH-H
= 7.8 Hz, 4JH-H = 1.1 Hz, 1 H, H17), 6.89 (brm, 1 H, H13), 6.85 (ddd, 3JH-H = 8.5 Hz, 4JH-H = 2.5 Hz, 4JH-H
0.9 Hz, 1 H, H15), 3.71 (s, 3 H, O-Me), 1.40 (s, 9 H, tBu), 1.36 (s, 9 H, tBu’). 13C{1H} NMR (CD2Cl2,
=
75.48 MHz, 298 K): δ 159.8 (s, C14), 157.6 (s, C3/3’), 156.9 (s, C3/3’), 152.5 (s, C7’), 151.8 (s, C7), 140.2 (s,
C4), 136.9 (s, C4’), 136.8 (s, C1), 130.6 (s, C8), 130.0 (s, C5), 129.7 (s, C16), 126.9 (s, C5’), 126.5 (s, C6),
126.0 (s, C6’), 124.8 (s, C12), 124.2 (s, C17), 122.5 (s, C2), 121.1 (s, C9), 118.7 (s, C2’), 116.4 (s, C13), 115.2
(s, C15), 92.0 (s, C11), 90.0 (s, C10), 55.5 (s, O-Me), 34.9 (s, CMe3’ + CMe3), 31.5 (s, CMe3), 31.3 (s,
CMe3’). MS CI+: m/z [M+H]+ 474.3 (calc. 474.3).

Dalton Transactions
Page 18 of 22
View Article Online
DOI: 10.1039/C8DT00906F
18
Kinetic investigations
1a/b (0.005 g, 0.0087 mmol) was dissolved in dry CD2Cl2 (0.6 mL) in a J-Young NMR tube and an
initial 1H NMR spectrum was recorded to lock and shim the sample. In the open air, 1-AdSH (at varying
concentrations) was added to the NMR tube and the reaction was followed by 1H NMR spectroscopy.
Concentrations were determined by relative integration to an external standard. The spectra were
processed and the normalized concentration of 1a/b was monitored over the course of the reaction by
comparing the intensity of t-butyl signal with the spectrum at t = 0.
X-ray crystallographic analysis of compound 6. Crystal data: C70H86N2S2Au2, 2(C36H2B2NF30),
2‘O’. M = 3525.47. Triclinic, space group P-1 (no. 2), a = 15.0100(8), b = 15.8427(8), c = 16.5234(7) Å,
α = 70.367(4), β = 84.345(4), γ = 70.653(5) , V = 3491.5(3) Å3. Z = 2, Dc = 1.677 g cm-3, F(000) = 1736,
T = 295(1) K, μ(Mo-Kα) = 22.6 cm-1, λ(Mo-Kα) = 0.71073 Å.
Crystals are large colourless blocks. A fragment of one, ca 0.19 x 0.10 x 0.07 mm, was fixed in oil
on a glass fibre and mounted on an Oxford Diffraction Xcalibur-3/Sapphire3-CCD diffractometer,
equipped with Mo-Kα radiation and graphite monochromator. Intensity data were measured by thin-slice
ω- and φ-scans. Total no. of reflections recorded, to θmax = 22.5, was 37382 of which 9083 were unique
(Rint = 0.122); 6857 were 'observed' with I > 2σI. Data were processed using the CrysAlisPro-CCD and -
RED (1) programs.28 The structure was determined by the intrinsic phasing routines in the SHELXT
program27 and refined by full-matrix least-squares methods, on F2's, in SHELXL.29 The non-hydrogen
atoms were refined with anisotropic thermal parameters. Hydrogen atoms were included in idealised
positions and their Uiso values were set to ride on the Ueq values of the parent carbon and nitrogen atoms.
Two persistent difference peaks in the ‘solvent void’ were assigned as half-occupancy oxygen atoms, but
were not fully resolved. At the conclusion of the refinement, wR2 = 0.132 and R1 = 0.093 (2B) for all 9083
2
2
reflections weighted w = [σ2(Fo ) + (0.0402P)2]-1 with P = (Fo + 2Fc2)/3; for the 'observed' data only, R1 =
0.065. In the final difference map, the highest peak (ca 1.2 eÅ-3) was near to C(12). Scattering factors for
neutral atoms were taken from reference 30. Computer programs used in this analysis have been noted
above, and were run through WinGX31 on a Dell Optiplex 780 PC at the University of East Anglia.
Acknowledgement
This work was supported by the European Research Council. M.B. is an ERC Advanced Investigator
Award holder (grant no. 338944-GOCAT). We thank the the EPSRC UK National Mass Spectrometry
Facility at Swansea University for collection of mass spectrometry data.

Page 19 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
19
Conflicts of interest
There are no conflicts to declare.
†Electronic supplementary information (ESI) available: Experimental details, Crystal structure diagrams,
NMR spectra. See DOI: 10.1039/xxxxxx. CCDC code: 1818966 contains the 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.
References
1
(a) M. N. Hopkinson, A. D. Gee, and V. Gouverneur, Chem. Eur. J. 2011, 17, 8248; (b) H. A.
Wegner and M. Auzias, Angew. Chem. Int. Ed. 2011, 50, 8236.
2
3
4
M. Joost, A. Amgoune, and D. Bourissou, Angew. Chem. Int. Ed. 2015, 54, 15022.
V. J. Scott, J. A. Labinger, and J. E. Bercaw, Organometallics 2010, 29, 4090.
(a) N. P. Mankad and F. D. Toste, Chem. Sci., 2012, 3, 72; (b) M. S. Winston, W. J. Wolf, and F.
D. Toste, J. Am. Chem. Soc. 2015, 137, 7921.
5
(a) A. Nijamudheen, S. Karmakar, and A. Datta, Chem. Eur. J. 2014, 20, 14650; (b)
R.Bhattacharjee, A. Nijamudheen, and A. Datta, Chem. Eur. J. 2017, 23, 4169.
6
H. Kawai, W. J. Wolf, A. G. Di Pasquale, M. S. Winston, and F. D. Toste, J. Am. Chem. Soc.
2016, 138, 587.
7
(a) S. Lavy, J. J. Miller, M. Pažický, A.-S. Rodrigues, F. Rominger, C. Jäkel, D. Serra, N.
Vinokurov, and M. Limbach, Adv. Synth. Catal. 2010, 352, 2993; (b) J. Serra, T. Parella and X. Ribas,
Chem. Sci., 2017, 8, 946.
8
(a) G. Mann, D. Baranano, J. F. Hartwig, A. L. Rheingold, and I. A. Guzei, J. Am. Chem. Soc.
1998, 120, 9205; (b) E. Alvaro, J. F. Hartwig, J. Am. Chem. Soc. 2009, 131, 7858; (c) M. Platon, N.
Wijaya, V. Rampazzi, L.-C. Cui, Y. Rousselin, M. Saeys, and J. C. Hierso, Chem. Eur. J. 2014, 20,
12584; (d) M. Cong, Y. T. Fan, J. M. Raimundo, Y. Xia, Y. Liu, G. Quelever, F. Q. Qu, and L. Peng,

Dalton Transactions
Page 20 of 22
View Article Online
DOI: 10.1039/C8DT00906F
20
Chem. Eur. J. 2013, 19, 17267; (e) M. Iwasaki, M. Iyanaga, Y. Tsuchiya, Y. Nishimura, W. J. Li, Z. P.
Li, and Y. Nishihara, Chem. Eur. J. 2014, 20, 2459; (f) X.-S. Zhang, G. X. Li, X.-G. Zhang and X.-H.
Zhang, Tetrahedron 2015, 71, 5458; (g) D. D. Xu, X. T. Qi, M. Duan, Z. Y. Yu, L. Zhu, C. H. Shan, X.
Y. Yue, R. P. Bai and Y. Lan, Org. Chem. Front. 2017, 4, 943.
9
Reviews: (a) C. C. Eichman and J. P. Stambuli, Molecules 2011, 16, 590; (b) Z. J. Qiao and X. F.
Jiang, Org. Biomol. Chem. 2017, 15, 1942.
10
S. D. Timpa, C. J. Pell and O. V. Ozerov, J. Am. Chem. Soc. 2014, 136, 14772.
11
Y. Yang, W. Hou, L.-H. Qin, J.-J. Du, H.-J. Feng, B. Zhou, and Y.-C. Li, Chem. Eur. J. 2014, 20,
416.
12
K. K.-Y. Kung, H.-M. Ko, J.-F. Cui, H.-C. Chong, Y.-C. Leung and M.-K. Wong, Chem.
Commun., 2014, 50, 11899.
13
R. E. Bachman, S. A. Bodolosky-Bettis, C. J. Pyle, and M. A. Gray, J. Am. Chem. Soc. 2008,
130, 14303.
14
(a) L. Currie, J. Fernandez-Cestau, L. Rocchigiani, B. Bertrand, S. J. Lancaster, D. L. Hughes, H.
Duckworth, S. T. E. Jones, D. Credgington, T. J. Penfold and M. Bochmann, Chem Eur. J. 2017, 23, 105;
(b) J. Fernandez-Cestau, B. Bertrand, M. Blaya, G. A. Jones, T. J. Penfold and M. Bochmann, Chem.
Commun. 2015, 51, 16629.
15
Reviews: (a) D.-A. Roşca, J. A. Wright and M. Bochmann, Dalton Transactions 2015, 44, 20785;
(b) R. Kumar and C. Nevado, Angew. Chem. Int. Ed. 2017, 56, 1994.
16
(a) D.-A. Roşca, D. A. Smith, D. L. Hughes and M. Bochmann, Angew. Chem. Int. Ed. 2012, 51,
10643. (b) N. Savjani, D.-A. Roşca, M. Schormann and M. Bochmann, Angew. Chem. Int. Ed. 2013, 52,
874. (c) D.-A. Roşca, J. Fernandez-Cestau, J. Morris, J. A. Wright and M. Bochmann, Science Adv. 2015,
1, e1500761. (d) A. Pintus, L. Rocchigiani, J. Fernandez-Cestau, P. H. M. Budzelaar, and M. Bochmann,
Angew. Chem. Int. Ed. 2016, 55, 12321. (e) L. Rocchigiani, J. Fernandez-Cestau, G. Agonigi, I.
Chambrier P. H. M. Budzelaar, M. Bochmann, Angew. Chem. Int. Ed. 2017, 56, 13861.
17
(a) B. Bertrand, J. Fernandez-Cestau, J. Angulo, M. M. D. Cominetti, Z. A. E. Waller, M.
Searcey, M. A. O’Connell and M. Bochmann, Inorg. Chem. 2017, 56, 5728. (b) B. Bertrand, M. A.
O’Connell, Z. A. E. Waller and M. Bochmann, Chem Eur. J. 2018, 24, 3613.

Page 21 of 22
Dalton Transactions
View Article Online
DOI: 10.1039/C8DT00906F
21
18
M. Williams, A. I. Green, J. Fernandez-Cestau, D. L. Hughes, M. A. O’Connell, M. Searcey, B.
Bertrand and M. Bochmann, Dalton Trans., 2017,46, 13397.
19
20
T. Zou, C. T. Lum, S. S.-Y. Chui, and C.-M. Che, Angew. Chem. Int. Ed. 2013, 52, 2930.
(a) J. Vicente, M. Dolores Bermúdez, J. Escribano, M. P. Carrillo, and P. G. Jones, J. Chem. Soc.,
Dalton Trans. 1990, 3083; (b) J. Vicente, M. Dolores Bermúdez, and J. Escribano, Organometallics 1991,
10, 3380.
21
S. J. Lancaster, A. Rodriguez, A. Lara-Sanchez, M. D. Hannant, D. A. Walker, D. L. Hughes and
M. Bochmann, Organometallics 2002, 21, 451.
22
L. Rocchigiani, J. Fernandez-Cestau, P.H.M. Budzelaar, and M. Bochmann, Chem. Commun.,
2017, 53, 4358.
23
N. Savjani, S. Bew, D. L. Hughes, S. J. Lancaster, and M. Bochmann, Organometallics 2012, 31,
2534.
24
I. Chambrier, D.-A. Roşca, J. Fernandez-Cestau, D. L. Hughes, P. H. M. Budzelaar, and M.
Bochmann, Organometallics 2017, 36, 1358.
25
26
27
K.-H. Wong, K.-K. Cheung, M. C.-W. Chan, and C.–M. Che, Organometallics 1998, 17, 3505.
D. A. Smith, D.-A. Roşca, M. Bochmann, Organometallics 2012, 31, 5988.
J. Fernández-Cestau, N. Giménez, E. Lalinde, P. Montaño, M. T. Moreno, S. Sánchez, M. D.
Weber and R. D. Costa, Dalton Trans. 2016, 45, 3251.
28
Programs CrysAlisPro, Oxford Diffraction Ltd., Abingdon, UK (2014).
29
G. M. Sheldrick, SHELX-97 – Programs for crystal structure determination (SHELXT) and
refinement (SHELXL), Acta Cryst. 2008, A64, 112; 2015, A71, 3, and 2015, C71, 3.
30
'International Tables for X-ray Crystallography', Kluwer Academic Publishers, Dordrecht 1992,
vol. C, pp. 500, 219 and 193.
31
L. J. Farrugia, J. Appl. Cryst. 2012, 45, 849.

Dalton Transactions
Page 22 of 22
View Article Online
DOI: 10.1039/C8DT00906F
1
Thiols were found to cleave Au-C bonds in (C^N^C)gold(III) pincer complexes and to induce C-S reductive
elimination reactions, to give aryl thioethers.