Ruthenium(0)-Catalyzed Cross-Coupling of Anilines with Organoboranes by Selective Carbon-Nitrogen Cleavage

Article abstract of DOI:10.1021/acscatal.9b02440

Selective activation of neutral carbon-nitrogen bonds is of great synthetic importance, because amines are among the most prevalent motifs across organic and bioactive molecules. Herein, we report the Ru(0)-catalyzed selective cleavage of neutral C(aryl)-N bonds in generic aniline derivatives enabled by a combination of Ru₃(CO)₁₂ and an imino auxiliary. These mild conditions provide a direct route to high-value biaryl ketones and biaryl aldehydes after facile in situ hydrolysis. A broad range of organoboranes and anilines can be coupled with high C-N cleavage selectivity. Most crucially, the reaction achieves exquisite selectivity for activation of C(aryl)-N bonds in the presence of typically more kinetically favorable C(aryl)-H bonds. The method provides a strategy for the construction of functionalized terphenyls by exploiting orthogonal properties of the Ru(0) catalyst system and traceless nucleophilic properties of anilines.

Full text of DOI:10.1021/acscatal.9b02440

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Letter
Ruthenium(0)-Catalyzed Cross-Coupling of Anilines with
Organoboranes by Selective Carbon–Nitrogen Cleavage
QUN ZHAO, Jin Zhang, and Michal Szostak
ACS Catal., Just Accepted Manuscript • DOI: 10.1021/acscatal.9b02440 • Publication Date (Web): 22 Jul 2019
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ACS Catalysis
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Ruthenium(0)-Catalyzed Cross-Coupling of Anilines with
Organoboranes by Selective Carbon–Nitrogen Cleavage
Qun Zhao,† Jin Zhang,†,§ and Michal Szostak*,†
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†Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States
§College of Chemistry and Chemical Engineering and Key Laboratory of Auxiliary Chemistry and Technology for
Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an 710021, China
Supporting Information
Ru(0)-catalyzed direct activation of neutral CN bonds in anilines
Bnep
O
NR
Ru(0) catalyst
Me
Me
NMe2
+
Ar1
R1
Ar1
Ar2
then H
37 examples
up to 95% yield
R2
R1
Ar2
 ketones and aldehydes
 neutral conditions
 1°, 2°, 3° amines
R2
C N > C H activation selectivity


ABSTRACT: Selective activation of neutral carbon–nitrogen bonds is of great synthetic importance because amines are
among the most prevalent motifs across organic and bioactive molecules. Herein, we report the Ru(0)-catalyzed selective
cleavage of neutral C(aryl)–N bonds in generic aniline derivatives enabled by a combination of Ru3(CO)12 and an imino
auxiliary. These mild conditions provide a direct route to high-value biaryl ketones and biaryl aldehydes after facile in situ
hydrolysis. A broad range of organoboranes and anilines can be coupled with high C–N cleavage selectivity. Most
crucially, the reaction achieves exquisite selectivity for activation of C(aryl)–N bonds in the presence of typically more
kinetically favorable C(aryl)–H bonds. The method provides a strategy for the construction of functionalized terphenyls
by exploiting orthogonal properties of the Ru(0)-catalyst system and traceless nucleophilic properties of anilines.
KEYWORDS: C–N activation, ruthenium, anilines, carbon–nitrogen cleavage, cross-coupling
The direct activation of neutral carbon–nitrogen bonds
may have a tremendous impact on organic synthesis
because amines are among the most commonly
encountered motifs in synthetic and bioactive
molecules.1,2 Because neutral C–N bonds are typically
inert, the catalytic and stoichiometric cleavage of neutral
C–N has been extremely rare.3 Typical activation of C–N
bonds involves converting the nitrogen into highly
reactive intermediates, such as diazonium salts,4
ammonium salts,5 pyridinium salts,6 or amides,7 including
conformationally-enforced C–N scission in twisted
amides.8 To date, only two examples of directed catalytic
functionalization of neutral C(aryl)–N bonds in anilines
have been achieved. Kakiuchi reported RuH2(CO)(PPh3)3
for scission of C–N bonds in sterically-hindered ketones
(Figure 1A).9 Zeng developed an efficient platform for
Kumada cross-coupling of C(aryl)–N bonds using low-
valent chromium catalysis (Figure 1A).10 Herein, we report
the Ru(0)-catalyzed selective cleavage of neutral C(aryl)–
N bonds (Figure 1B-C) in generic aniline derivatives
enabled by a combination of Ru3(CO)12 and an imino
auxiliary as a highly effective regioselectivity control
principle for C(aryl)–N activation (Figure 1D).
Our laboratory has been interested in activation of C–N
bonds as a versatile platform for catalysis.11 In contrast to
the continuing evolution of activation of C–H bonds,12 the
direct activation of neutral C–N bonds remains an
unsolved synthetic task. The broad interest in activation
of neutral C(aryl)–N bonds is twofold: (1) unprecedented
potential to establish orthogonal strategies for
functionalization of inherently and naturally-occurring
amine motifs; (2) the use of electron-donating,
nucleophilic NR2 group as a traceless functional handle to
selectively install functional groups impossible with inert
C–H bonds.
The present method significantly advances nucleophilic
ruthenium-catalysis13–20 for activation of neutral C(aryl)–N
bonds. An important example reported by Shi20 describes
a non-directed, Ni-catalyzed, Mg mediated cross-coupling
of C–N bonds that is limited to conjugated arenes.
Notable features of our findings include: (1) in contrast to
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the previous state-of-the-art, the reaction does not
Page 2 of 8
neopentyl aryl boronate26 (2) as nucleophile in toluene at
100 °C providing the desired product in 83% yield (Table
1, entry). It is noteworthy that the reaction
1
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5
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7
8
require
B. Untapped potential
A. Cleavage of neutral CN bonds
 Kakiuchi [ref 9]
Table 1. Optimization of Reaction Conditionsa
 Zeng [ref 10]
t-Bu
N
R1
R3
Bnep
NPh
NPh
Me
H
R2
Ru3(CO)
12 (5 mol%)
neutral CN bond
O
N
Me
NMe2
+
Ar1
Ar1
Ar2
selective
toluene, 100 °C
activation M n
[
]
NMe2
NMe2
Ar2
R1
1
2
3
R3
RuH2(CO)(PPh3)3
CrCl2/RMgX
N
variation from the
standard conditions
conversionb
yieldb
(%)
9
limited to sterically-bulky ketones
incompatible with esters, ketones, halides strong organometallics
low-valent Cr catalysis
M n+2
R2
entry
(%)
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C. Activation tactics in catalysis
 CH bonds
 neutral CN bonds
1
2
no change
>98
10
83
<5
<5
<5
<5
<5
<5
DG
DG
H
DG
DG
H
RuH2(CO)(PPh3)3
RuH2(PPh3)4
H
NR2
3
5
many examples
extremely rare
4
RhCl(PPh3)3
14
D. This study: Ru(0)-catalyzed direct activation of neutral CN bond in anilines
5
[Rh(COD)Cl]2
[RuCl2(p-cym)]2
[RuCl2(p-cym)]2
>98
>98
>98
Bnep
O
NR
Me
NMe2
6c
7d
Ru(0) catalyst
Me
+
Ar1
R1
Ar1
Ar2
then H
37 examples
up to 95% yield
R2
R1
Ar2
Ph-Bpin instead of Ph-
Bnep
Ph-BF3K instead of Ph-
Bnep
Ph-B(OH)2 instead of Ph-
Bnep
Ph-Si(OMe)4 instead of
Ph-Bnep
 ketones and aldehydes
 neutral conditions
 1°, 2°, 3° amines
R2
8
9
>98
11
73
<5
<5
<5
C N > C H activation selectivity


Figure 1. Context of the present work: A) Examples of N–C
activation; B) Untapped potential of neutral N–C activation; C)
Tactics in catalysis; D) Present study: the first Ru(0)-catalyzed
mono-selective activation of neutral N–C bonds.
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bulky pivaloyl groups to afford regioselective C–N (vs. C–
H) activation;21 (2) the product acetophenones are
essential compounds in organic synthesis and can be
readily functionalized through classical enolate
activation;22 (3) the method can be applied for the
synthesis of biaryl aldehydes by C(aryl)–N activation after
mild in situ hydrolysis first time in Ru(0)-catalysis;23 (4)
the method exploits unprecedented functional group
tolerance of Ru3(CO)12 (halides, esters, ketones) that is
unattainable with RuH2(CO)(PPh3)313–15 and thus
establishes a unique strategy for the construction of
functionalized and broadly useful terphenyls; (5) most
remarkably, the method is highly selective for C(aryl)–N
activation in the presence of multiple C–H bonds (8:1 C–N
selectivity vs. 3 possible C–H activation sites).24
11e
12
13
16
125 °C instead of 100 °C
>98
>98
80
76
Ph-Bnep 1.5 equiv instead
of 1.1 equiv
aConditions: imine (1.0 equiv), PhBnep (1.1 equiv), catalyst (5 mol%),
toluene (1.0 M), 100 °C. bDetermined by 1H NMR and GC. cPh–B(OH)2
d
(3 equiv), AgSbF6 (12 mol%), Cu(OAc)2H2O (1.0 equiv). Ph–B(OH)2
(2 equiv), Ag2O (1.0 equiv), Cu(OTf)2 (1.0 equiv). eKF (1.0 equiv). Bnep
= 5,5-dimethyl-1,3,2-dioxaborolane. See SI for details.
proceeded with unprecedented mono-arylation selectivity
(C–N vs. combined C–N and C–H selectivity >10:1), and it
did not require the presence of hydride acceptor or
inorganic base additives. Selected optimization results are
outlined in Table 1. Various catalysts were tested, and
Ru3(CO)12 proved the most effective, in agreement with
our design (entries 1-7). Neopentyl aryl boronate is the
preferred nucleophile (entries 8-11). Specifically, the use of
pinacol aryl boronate is feasible but less efficient due to
material decomposition (entry 8). At the present stage,
other nucleophiles are ineffective (entries 9-11). The effect
of temperature and stoichiometry is critical for the
efficient C–N activation, with higher temperatures or
higher loading of nucleophile leading to competing di-
arylation (entries 12-13). Finally, N-Ph imine is the
preferred imine auxiliary for ketone arylation, with N-
alkyl imines leading to low conversions due to imine
decomposition (not shown), while bulky N-Ar imines are
vastly preferred for aldehyde arylation to control mono-
selective activation of C(aryl)–N bond (see SI).
Unlike pivaloyl groups, simple ketones and aldehydes
are readily amenable for synthetic manipulations.
Synthetically-useful mono-arylation requires the catalyst
to de-coordinate from the directing group.16j,k This has
been
the
major
issue
with
ketone-directed
RuH2(CO)(PPh3)3 neutral C(aryl)–N activation, requiring
the presence of a bulky pivaloyl group. We hypothesized
that a strategy using imine auxiliary25 and much more
selective Ru3(CO)12 would provide a milder and more
attractive approach to neutral C(aryl)–N activation. In
this scenario the competing C–H activation is kinetically
inaccessible, making the C–N bond the preferred
activation site. Reaction of acetophenone ketimine (1) was
investigated as a model system (Table 1). After extensive
optimization, best results were obtained using N-Ph
imine (1) as C–N functionalization substrate and
2
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Having identified optimal conditions, the scope of this
Bnep
O
NPh
Ru3(CO)
12 (5 mol%)
1
2
3
4
5
6
Me
Me
NR2
novel neutral C(aryl)–N activation was next investigated
(Scheme 1). We were delighted to find that a wide range
of organoboranes readily participates in this cross-
+
Ar1
Ar1
Ar2
toluene, 100 °C
then HCl
Ar2
1
2
3
Scheme 1. Ru(0)-Catalyzed C(Aryl)–N Activation:
Ketiminesa,b
Ar1NR2
NPh
NPh
Me
NPh
Bnep
O
NPh
Me
NMe2
Me
NHMe
7
8
9
Ru3(CO)
12 (5 mol%)
Me
Me
NMe2
NH2
+
Ar1
Ar1
Ar2
toluene, 100 °C
then HCl
R
1a 80% yield
:
1ab 55% yield
1ac 60% yield
:
:
Ar2
1
2
3
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R
NPh
NPh
Me
Ar1Ar2
Me
NEt2
O
O
O
N
Me
Me
Me
1ad 71% yield
1ae 61% yield
:
:
CF3
F
a,bSee Scheme 1.
3a 80% yield
:
3b 83% yield
3c 74% yield
:
:
Scheme 3. Ru(0)-Catalyzed C(Aryl)–N Activation:
Trifluoromethyl Ketiminesa,b
O
O
O
Me
Me
Me
Bnep
O
CF3 NPh
CF3
Ru3(CO)
12 (5 mol%)
H
H
+
Ar1
Ar1
Ar2
toluene, 120 °C
then HCl
OMe
NMe2
COMe
NMe2
R
Ar2
3d 84% yield
:
3e 80% yield
3f 82% yield
:
:
1
2
3
R
H
O
O
O
Ar1Ar2
CF3
CF3
O
CF3
O
Me
Me
Me
O
H
O
O
H
CO2Me
F
OMe
3g 73% yield
:
3h 84% yield
3i 80% yield
:
:
3o 95% yield
:
3p 71% yield
3q 90% yield
:
:
O
O
O
CF3
O
CF3
O
CF3
O
Me
Me
Me
H
H
H
F
O
O
S
O
3j 85% yield
:
3k 65% yield
3l 65% yield
Cl
:
:
F
3r 73% yield
:
3s 80% yield
3t 70% yield
:
:
O
O
CF3
O
CF3
O
Me
Me
Ph
H
H
N
OMe
3m 72% yield
:
3n 71% yield
:
N
OMe
3u 92% yield
3v 70% yield
:
:
aImine (1.0 equiv), PhBnep (1.1 equiv), catalyst (5 mol%), PhMe (1.0
M), 100 °C, 15 h. bIsolated after hydrolysis. See SI for details.
aImine (1.0 equiv), PhBnep (1.1 equiv), catalyst (5 mol%), PhMe (1.0
M), 120 °C, 15 h. bIsolated after hydrolysis. See SI for details.
Scheme 2. Ru(0)-Catalyzed C(Aryl)–N Activation:
Amine Scopea,b
Scheme 4. Ru(0)-Catalyzed C(Aryl)–N Activation:
Aldiminesa,b
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Bnep
O
NR
Ru3(CO)
12 (5 mol%)
1
2
3
4
5
6
H
H
+
Ar1
Ar1
Ar2
toluene, 140 °C
then HCl
R = 2,6-i-Pr2-C6H3
NMe2
R
Ar2
1
2
3
R
H
Ar1Ar2
O
O
O
H
H
7
8
9
OMe
CO2Me
3w 73% yield
:
3x 62% yield
3y 60% yield
:
:
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(mono/di >10:1)
(mono/di = 7.8:1)
(mono/di = 8.4:1)
aImine (1.0 equiv), PhBnep (1.1 equiv), catalyst (5 mol%), PhMe (1.0
M), 140 °C, 15 h. bIsolated after hydrolysis. See SI for details.
Scheme 5. Ru(0)-Catalyzed in situ C–N Activation
O
Bnep
CF3
O
CF3
PhNH2 (1.0 equiv)
Ru3(CO)
12 (5 mol%)
H
H
+
MgSO4 (1.5 equiv)
K2CO3, PhMe, 140 °C
then HCl
NMe2
1b'
2a
[in situ method]
3o 88% yield
:
coupling. As shown, electronically-diverse nucleophiles,
including electron-neutral (3a), electron-deficient (3b-c),
and electron-rich (3d-e) organoboranes coupled with
high levels of efficiency. Note that the reaction is fully
selective for the cleavage of the electrophilic –NMe2
adjacent to the imine auxiliary (3e). It is notable that the
reaction is compatible with electrophilic carbonyl
handles,
Scheme 6. Synthetic Transformations and Sequential Catalysis Enabled by C(Aryl)–N Activation
CH activation
1st
A.
H
B.
O
O
O
Pd(OAc)2 (3 mol%)
DavePhos (3 mol%)
CMD
O
NBS
Br
Br
directing
& 2nd
Me
NMe2
Me
NMe2
Me
Me
NH4OAc
CH3CN, RT
pivOH (30 mol%)
K2CO3 (2.5 equiv)
NMe2
NMe2
4e 69% yield
4a
4b 99% yield
:
4b
:
benzene
:DMA, 120 °C
MeO
O
O
O
4-MeO-C6H4-B(OH)2
Pd(OAc)2 (2 mol%)
Me
Me
Me
step 1
step 2
Na2CO3 (1.0 equiv)
EtOH/H2O, 80 °C
NMe2
4c 98% yield
PhNH2
Ru3(CO)12
Ar-Bnep
:
O
4f 79% yield
:
4g 84% yield
:
Me
MeO
O
O
O
C.
Br
O
step 1
step 2
Br
Br
Me
Me
Me
step 1
PhNH2
step 2
Me
NMe2
PhNH2
Ru3(CO)12
Ar-Bnep
Ru3(CO)12
Ar-Bnep
O
CO2Me
4d 71% yield
:
4b
directing
& 1st
OMe
4h 73% yield
4i 80% yield
:
:
step 1
step 2
: PhNH2 (1.0 equiv), MS, PhMe (0.20 M), 140 °C, 24 h, then concentrate
Ar-Bnep
: Ru3(CO)12 (5 mol%),
(1.1 equiv), PhMe (1.0 M), 100 °C, 24 h, then HCl aq
including ketones (3f) and esters (3g), providing excellent
substrates for electrophilic functionalization strategies.
Note the facile installation of sterically-differentiated
ketones in 3f, another benefit of using mild imine
auxiliary approach. Furthermore, unprotected terminal
olefins (3h), polyaromatics (3j) and heterocycles, such as
furan (3k), thiophene (3l), are well-tolerated, furnishing
the C(aryl)–N cleavage products with high C–N scission
selectivity. We were pleased to find that functionalized
pyridines (3m) and styrenyl boronates (3n) are also
readily tolerated in this protocol, allowing incorporation
of various groups. Note that in all cases examined, we
observed exquisite C(aryl)–N vs. C–H activation selectivity
(>20:1), with mono- vs. di-arylation selectivity typically
>15:1 favoring the thus far unattainable mono-arylation
products. An important feature of the Ru(0)-methodology
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is the capacity to tolerate sensitive functional groups on
Furthermore, C–H activation could be implemented in
the sequence by exploiting the Pd-catalyzed CMD
(concerted-metallation-deprotonation) pathway (Scheme
6B).28 Ultimately, this
both reaction components.13,15,18e,f All starting materials are
readily accessible from the corresponding anilines or by
established methods.26b At the present stage of reaction
development alkylboronates are not compatible.
Preliminary results suggest that it is possible to prepare
arylboronates in situ to improve atom economy. Efforts
are currently underway to expand the scope of the C–N
cleavage methodology and these studies will be reported
in due course.
1
2
3
4
5
6
7
8
Scheme 7. Selectivity Studies
A


NPh
. 2-C N vs. 4-C N activation
O
Ru3(CO)12 (5 mol%)
Me
Me
2a
2a
2a
+
PhMe, 100 °C
then H+
Me2N
NMe2
Me2N
9
2-CN vs. 4-CN >95:5
5a
5b 70% yield
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12
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:
Importantly, we determined that various neutral
anilines, including dimethyl –NMe2 (1a), unprotected –
NH2 (1ab), mono-alkyl –NHMe (1ac), more sterically-
hindered –NEt2 (1ad) and cyclic –pyrrolidine (1ac)
(Scheme 2) undergo the Ru(0)-catalyzed activation/cross-
coupling under the developed conditions with high
C(aryl)–N activation selectivity, attesting to the generality
of our protocol.
B


. C N vs. C O activation
OMe NPh
OMe O
H
Ru3(CO)12 (5 mol%)
H
+
PhMe, 80 °C
then H+
NMe2
CN vs. CO >95:5
5c
5d 75% yield
:
C

. C N vs. C H activation

Ph
H
We were further delighted to find that C(aryl)–N
activation in aldehyde derivatives is also possible by using
imine directing auxiliary (Scheme 3). The ortho-CF3-
aniline was used as a model substrate, and thus provided
access to trifluoromethyl-biaryl aldehyde building blocks
H
H
O
N
H
Ru3(CO)12 (5 mol%)
+
H
H
PhMe, 80 °C
then H+
NMe2
CN vs. 3 x CH = 8:1
5e
5f 60% yield
:
which
prominently
feature
in
pharmaceutical,
Scheme 8. Mechanistic Studies
agrochemical and functional materials applications due to
unique properties of fluorine. In general, the yields
observed (Scheme 3) matched the C(aryl)–N activation of
ketone substrates (Scheme 4). To our knowledge, this
reaction represents the first example of generating a
versatile biaryl aldehyde linchpin in ruthenium-catalyzed
neutral C–N activation.13–15
A
. Intermolecular competition: imines
NPh
NPh
Me
NPh
Me
Ph
Ru3(CO)12 (5 mol%)
2a
(1.0 equiv)
R
F3C
Me
Me
+
PhMe, 100 °C
NMe2
Ph
3z 3aa
1d/1e
R = CF3/Me
3aa
3z
(2.0 equiv each)
:
= 72:28
B
. Intermolecular competition: nucleophiles
Remarkably, the direct C(aryl)–N activation of unbiased
aldehydes is also feasible (Scheme 4). In these cases, we
found that the use of a sterically-bulky N-aryl imine is
preferred to prevent di-arylation. It is well-established
that in benzylideneanilines the aromatic ring is twisted
from the imine plane, while the presence of ortho-
substituents increases the twist.27 Thus, representative
examples using neutral (3w), electron-rich (3x) and
electron-deficient (3y) proceeded with unprecedented
>7:1 selectivity for neutral C(aryl)–N arylation.
Bnep
Bnep
NPh
Me
NPh
Ru3(CO)12 (5 mol%)
1a
(1.0 equiv)
Me
+
+
PhMe, 100 °C
OMe
2d
(2.0 equiv each)
CF3
2b
OMe
CF3
3d
3b
3d 3b
:
= 48:52
suggests a great potential of a C(Ar)–Br synthetic handle
for post-activation transformations. Indeed, the mild
Ru3(CO)12 catalyst permits direct C(aryl)–N activation in
the presence of a very sensitive aryl bromide (Scheme
6C). To our knowledge this represents the first example of
functional group tolerance for an aryl bromide in the
C(aryl)–N bond activation manifold.
The synthetic advantage of the mild imine auxiliary
approach and Ru(0)-catalysis is that the C(aryl)–N
activation can be readily performed directly from a
carbonyl by an in situ imine synthesis/hydrolysis (Scheme
5).
Importantly, to have a broad impact, a catalyst system
must be selective over other potential activation sites.12 To
determine the inert bond activation selectivity of the
present system, we studied the intramolecular
competition for C(aryl)–N vs. C(aryl)–N, C(aryl)–N vs.
C(aryl)–O and C(aryl)–N vs. C(aryl)–H activation (Scheme
7). To our delight we found that this mild Ru(0)-imine
method gives full selectivity for the C(aryl)–N activation
at the ortho-position (2-C–N vs. 4-C–N, >20:1) (Scheme
7A), consistent with a directing effect of the imine
auxiliary. Furthermore, we observed full selectivity for
C(aryl)–N vs. C(aryl)–O activation (>20:1) (Scheme 7B),
We next turned our attention to demonstrate the
synthetic potential of the neutral C(aryl)–N arylation. As
the key advantage the presence of a neutral aniline
furnishes a unique strategy for the construction of
functionalized molecules by exploiting orthogonal
properties of the Ru(0)-catalyst system and traceless
nucleophilic properties of anilines. This is demonstrated
by facile assembly of functionalized terphenyls via
electrophilic bromination/ Suzuki cross-coupling/Ru(0)-
catalyzed neutral C(aryl)–N activation (Scheme 6A).
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Page 6 of 8
thanks the China Scholarship Council (201808610096). We
despite the well-established potential for metal insertion
into –OMe bonds.29 Most remarkably, we found an
excellent selectivity for C–N activation in the presence of
multiple C–H bonds (8:1 C–N selectivity vs. 3 possible C–H
1
2
3
4
5
6
7
8
thank Dr. Feng Hu (Rutgers University) for experimental
assistance. The Bruker 500 MHz spectrometer used in this
study was supported by the NSF-MRI grant (CHE-1229030).
activation sites)
(Scheme 7C). These results are
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via mono-arylation.
functional group tolerance, and provides
The method shows excellent
unique
a
strategy for the synthesis of biaryls by utilizing orthogonal
features of the Ru(0)-catalyst and nucleophilic properties
of anilines. The discovery that the reaction achieves full
selectivity for activation of C(aryl)–N bonds in the
presence of typically more kinetically favorable C(aryl)–H
bonds is likely to facilitate the design of future catalyst
systems and may also be applicable to the activation of
other C(aryl)–X bonds.
ASSOCIATED CONTENT
Supporting Information
Experimental procedures and characterization data. This
material is available free of charge via the Internet at
http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
michal.szostak@rutgers.edu
ACKNOWLEDGMENT
Financial support was provided by Rutgers University. M.S.
gratefully acknowledges the NSF (CAREER CHE-1650766)
and the ACS PRF (DNI-55549) for generous support. J.Z.
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(26) (a) For a comprehensive review on C–H arylation with
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Catalyzed, Directed C–H Coupling with Organometallics. Adv.
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Alkoxybenzaldehydes for the Synthesis of Olefin Metathesis
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therein.
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