Copper mediated decarboxylative direct C-H arylation of heteroarenes with benzoic acids

Article abstract of DOI:10.1039/c5cc08367b

Decarboxylative coupling reactions to date require a stoichiometric oxidant (such as copper and silver salts) for decarboxylation purposes along with a metal catalyst (e.g. palladium) for cross-coupling. In this communication, an economic and sustainable approach by using a simple copper salt was developed in the presence of molecular oxygen as the sole oxidant. A wide range of 5-membered heteroarenes undergo aryl-heteroaryl cross-coupling with electron deficient aryl carboxylic acids.

Full text of DOI:10.1039/c5cc08367b

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: T. Patra, S. Nandi,
S. K. Sahoo and D. Maiti, Chem. Commun., 2015, DOI: 10.1039/C5CC08367B.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
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
Information for Authors.
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 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.
www.rsc.org/chemcomm

Please do not adjust margins
ChemComm
Page 1 of 4
View Article Online
DOI: 10.1039/C5CC08367B
ChemComm
COMMUNICATION
Copper Mediated Decarboxylative Direct C‒H Arylation of
Heteroarenes with Benzoic Acids†
Tuhin Patra,a Sudip Nandi,a Santosh K. Sahooa and Debabrata Maiti*,a
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
Decarboxylative coupling reactions till date required methods often produce toxic and stoichiometric side-
stoichiometric oxidant (such as copper and silver salts) for products.3 Alternatively, carboxylic acids are an exciting choice
decarboxylation purpose along with
a metal catalyst (e.g. in place of traditional organometallic counterpart since they
palladium) for cross coupling. In this communication, an are widely available, inexpensive and easy to store and
economic and sustainable approach by using simple copper salt handle.4 Most importantly, transition metal catalyzed
was developed in presence of molecular oxygen as the sole- decarboxylation of aromatic carboxylic acids can provide same
oxidant. A wide range of 5-membered heteroarenes undergo aryl- aryl-metal intermediates by loss of CO2.5
heteroaryl cross-coupling with electron deficient aryl carboxylic
Over recent years, benzoic acid derivatives have been
acids.
popularized mainly by Goossen6 and others7 as an alternative
Five membered heterocycles are recognized as important coupling partner with aryl halides and triflates.8 Consequently,
structural motifs in pharmaceuticals, agrochemicals, natural direct C‒H arylation reactions have been a prominent field of
products, functional organic materials and dye industries research since such transformations are capable of
(Figure 1).1 In this context, synthetic importance of azole streamlining organic synthesis and minimizing wasteful
derivatives ensured continuous interest of chemists to find byproducts.9
Therefore, a decarboxylative C‒H bond
effective methods for regiospecific formation of aryl- functionalization that combines these two newly emerging
heteroaryl bond.2
approaches, that is, decarboxylation and direct C‒H bond
functionalization, holds a great potential for new bond forming
strategies in synthesis. Interestingly, few methods have
already been reported using this decarboxylative direct
arylation approach. In these cases either Cu or Ag salt is used
in stoichiometric amount for decarboxylation purpose.10
Additionally, a Pd catalyst was often employed for cross
coupling.11,12 Employment of an economic, greener first row
transition metal, for example copper, to play the dual role of
decarboxylation followed by direct C‒H arylation in presence
of molecular oxygen is yet to be explored (Scheme 1).
N
O
Cl
Cl
N
N
N
O
OMe
O
HO2C
OH
Me
S
HO
Me
Tafamidis
Tomoxiprole
Raloxifene
N
O
N
N
O
NC
O
N
O
NH
N
H
O2N
Me
OMe
O
S
HO
N
N
Mefenidil
Dantrolene
Arzoxifene
X
X
N
X
N
X
X= S, O
X= S, O, NR
Figure 1. Few relevant aryl-heterocyclic cores in drug
Ar
ref. 11c
Ar
cat. Pd.
stoich. Ag2CO3
molecules
This work
(Cu in dual role)
Ar
CO2H
Previous work
Traditional cross-coupling methods generally require
expensive
heavy
transition
metals,
pre-activated
R
S
Y= O, S
Ar
Ar
organometallic coupling partners and as a result, these
cat. Pd.
stoich. Ag2CO3
S
R
Y
R
R
ref. 12
Y
a.Department of Chemistry, Indian Institute of Technology Bombay
Powai, Mumbai-400076, India
Email: dmaiti@chem.iitb.ac.in
Scheme 1. Decarboxylative C‒H arylation of heteroarenes
Copper mediated methods for protodecarboxylation are
well studied in literature.13,14 Additionally, copper is also used
†
Electronic Supplementary Information (ESI) available: Optimization details,
reaction procedure, characterization data and 1H, 13C NMR spectra. See
DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-4 | 1
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 4
View Article Online
DOI: 10.1039/C5CC08367B
COMMUNICATION
Journal Name
broadly in different C‒H functionalization reactions.15 Table 2. Scope of substrates for heteroarenes with two
Surprisingly, simple copper catalyzed/mediated method for heteroatoms16,a
CuBr (15-30 mol%)
1,10-phen (30-60 mol%)
decarboxylative direct C‒H arylation is under developed albeit
N
X
N
Ar
Ar
CO2H
H
+
of its practical importance and high demand in present
context. Herein we report first copper mediated C‒H arylation
of benzoic acid derivatives with different heteroarenes
(Scheme 1) using molecular O2.
K2CO3 (3 equiv.), toluene
O2, 140 °C
X
X= S, O, NR
1a-1d
2a-2d
3a-3i
heteroarene
product
yield (%)
entry
benzoic acid
NO2
NO2
N
S
N
S
Table 1. Optimization of reaction condition16,a
CO2H
H
H
H
76
53b
1
1a
2a
2b
3a
NO2
NO2
CO2H
NO2
N
S
N
S
Cu cat./ ligand
H
N
O
N
+
base (3 equiv.), oxidant
solvent
2
3
1a
1a
71
51c
O
1a
2a
3a
3b
NO2
NO2
Me
Me
NO2
N
N
N
N
Me
Me
74
H
N
N
43b
56c
N
N
O2N
Me
Me
3c
2c
1,10-phen
Me4-phen
4a
5a
NO2
N
N
N
N
Entry [Cu]
ligand
base
[O]
air
air
air
air
air
air
air
air
air
3a (%)
16
20
27
16
14
25
<1
12
24
20
28
57
63
71
-
H
1a
60
4
47c
1
CuCl2
CuBr2
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
--
1,10-phen
1,10-phen
1,10-phen
bipy
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
KHCO3
KF
Me
2d
Me
3d
2
NO2
NO2
3
N
5
6
Cl
CO2H
Cl
78
49b
2b
4
O
3e
5
TMEDA
1b
F
F
F
F
6
Me4-phen
--
N
S
7
2a
32
F
CO2H
CO2H
F
8
1,10-phen
1,10-phen
1,10-phen
1,10-phen
1,10-phen
1,10-phen
1,10-phen
1,10-phen
1,10-phen
1,10-phen
F
F
F
F
F
F
F
F
1c
3f
9
10
11
12
13b
14b,c
15
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2S2O8
DTBP
O2
N
S
36
23c
7
8
2a
2b
F
F
F
1d
3g
O2
F
O2
N
29
1d
O2
O
16b,c,d CuBr
17e
CuBr
O2
76
53
F
3h
aReaction conditions:
1
(0.6 mmol), CuBr (30 mol%), 1,10-
(0.2
O2
aReaction conditions:
mol%), base (3 equiv.),
1
(0.6 mmol), Cu salt (30 mol%), ligand (60
(0.2 mmol) in toluene (1 mL) at 130 ⁰C for 24
phenanthrolene (60 mol%), K2CO3 (0.6 mmol), 4 Å MS (30 mg),
2
mmol), DTBP (25 mol%) in toluene (1 mL) under O2 atmosphere at 140
c
2
⁰C for 24 h. bCuBr (15 mol%), 1,10-phenanthrolene (30 mol%). CuBr
h. Yields were determined by gas chromatography using n-decane as
d
internal standard. 25 mol% DTBP was used. 4 Å MS (30 mg). 140 °C.
eCu salt (15 mol%), ligand (30 mol%).
b
c
(20 mol%), 1,10-phenanthrolene (40 mol%).
Less polar solvents (toluene, xylene) provided desired coupling
product in 15-20% yield along with varying amount of 4a and
5a 16
Detailed evaluation of model reaction system by varying
At the outset, we hypothesized that benzoic acid
derivatives in presence of suitable copper salt can effectively
produce direct C‒H arylation product with 5-membered
heteroarenes in regioselective manner due to the intrinsic
electronic bias among different C‒H bonds. To test this
presumption, 2-nitrobenzoic acid was employed with
benzothiazole in presence of CuCl2/ 1,10-phen and a base in
different solvents. During optimization studies, we realized
that choice of solvent plays a critical role to obtain the desired
product. Polar aprotic solvent (DMSO, DMF) gave expected
compound in trace amount along with undesired 2,2'-dinitro-
1,1'-biphenyl (5a) as the major product. On the other hand,
polar protic solvents (EtOH, t-BuOH) resulted in
protodecarboxylative product, nitrobenzene (4a).
.
different copper salts and ligands revealed that CuBr along
with simple 1,10-phenanthroline can promote the desired
reaction (Table 1, entries 1-6). Choice of base is also crucial
since in absence of base no cross-coupled product was
determined, and weak bases were found to produce better
results (entries 8-9).16 Introduction of an oxidant, especially
molecular oxygen improved the yield significantly. In careful
control it was found that addition of 25 mol% of di-tert-
butylperoxide (DTBP) with oxygen atmosphere can improve
the yield further to 63% (entries 10-13).
Increase in
temperature beyond 140 °C promoted formation of 5a
significantly by suppressing desired product formation.16
Control experiments confirmed that copper is responsible for
2 | J. Name., 2013, 00, 1-4
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 3 of 4
View Article Online
DOI: 10.1039/C5CC08367B
Journal Name
COMMUNICATION
decarboxylation as well as direct C‒H arylation (entry 15) in
presence of molecular oxygen.16
Next, we were intrigued by the possibility whether
thiophene moiety can be employed in our current
With this optimized condition, scope of the reaction was methodology or not. Thiophenes are less reactive compared
investigated with 2-nitrobenzoic acid by varying different 5- to azole derivatives, and previously stoichiometric silver salts
membered heterocycles containing 2-heteroatoms.
benzothiazole, benzoxazole and benzimidazole core was found with thiophenes.12 To our delight, benzothiophene delivered
to provide desired products in good yields (Table 2, entries 3a the C‒H arylated product under the present reaction condition
All were used with palladium catalyst for decarboxylative coupling
,
3b and 3c). This observation ruled out the possibility of ring in synthetically useful yield (Table 3, entry 3i). Next, scope of
opening of benzothiazole, followed by imine formation and different thiophene derivatives were contemplated with 2-
cyclization pathway, as observed in earlier cases to deliver only nitrobenzoic acid as model substrate. Aldehyde, cyano and
benzothiazole coupled products.17 The N-protected imidazole halogen-substitutions were tolerated successfully (entries 3j
compounds also furnished decarboxylated coupling product in 3k 3l). We were pleased to find that not only thiophene, but
synthetically useful yield (entry 3d). Chloro substituted 2- furan moiety can also be used successfully in our present
nitrobenzoic acid found effective to deliver heteroarylated methods (entry 3m). Although this newly described
,
,
product with benzoxazole (entry 3e). During exploration of methodology is sensitive towards choice of benzoic acids, but
scopes for substrates we realized this current method is highly enjoys a wide range of variation in heterocycles.
sensitive towards choice of benzoic acid. Mainly, benzoic acids
with electron withdrawing groups are prone for easy
decarboxylation to provide aryl-copper intermediate14 and
likely to deliver desired direct C‒H arylated product.
Accordingly, different fluoro substituted electron withdrawing
benzoic acids were employed to obtain fluoro substituted
heteroarylated coupling products successfully albeit of low
yields (entries 3f, 3g, 3h). Please note that decarboxylative
coupling reactions are usually very sensitive towards electronic
nature of the partners involved.11
Table 3. Scope of substrates for heteroarenes with one
heteroatom16,a
Scheme 2. Control experiments
CuBr (15-30 mol%)
1,10-phen (30-60 mol%)
Ar
Ar
CO2H
H
+
K2CO3 (3 equiv.), toluene
O2, 140 °C
Y
Y
Y= S, O
1a-1d
2e-2h
3j-3p
heteroarene
product
yield (%)
entry
benzoic acid
NO2
H
83
54b
1
1a
S
S
2e
3i
NO2
H
H
2
3
1a
1a
68
S
2f
S
3j
44c
CHO
Cl
CHO
Cl
NO2
NO2
73
46c
S
S
2g
3k
Scheme 3. Plausible mechanism
H
1a
1b
76
4
5
O
O
CN
CN
49c
2h
3l
After exploring scope of substrates, we tried to explicate
the mechanistic complexity for this newly developed protocol.
NO2
Cl
2g
70
57b
Control experiments
without
heterocycle provided
S
Cl
3m
decarboxylated products 4a and 5a, exclusively. Both 4a and
5a were unreactive during their independent reactions with
heterocycle. Again, homo-coupling of benzothiazole under the
reaction condition was found sluggish (Scheme 2).16 This
implies ligated copper species first forms copper salt of
benzoic acid followed by extrusion of CO2 to afford aryl-copper
intermediate.14 Additionally, a radical pathway may be
aReaction conditions:
1
(0.6 mmol), CuBr (30 mol%), 1,10-
(0.2
phenanthrolene (60 mol%), K2CO3 (0.6 mmol), 4 Å MS (30 mg),
2
mmol), DTBP (25 mol%) in toluene (1 mL) under O2 atmosphere at 140
c
⁰C for 24 h. bCuBr (15 mol%), 1,10-phenanthrolene (30 mol%). CuBr
(20 mol%), 1,10-phenanthrolene (40 mol%).
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-4 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 4
View Article Online
DOI: 10.1039/C5CC08367B
COMMUNICATION
Journal Name
7. (a) A. Voutchkova, A. Coplin, N. E. Leadbeater and R. H.
Crabtree, Chem. Commun., 2008, 47, 6312; (b) J.-J. Dai, J.-H. Liu,
D.-F. Luo and L. Liu, Chem. Commun., 2011, 47, 677; (c) S.
Messaoudi, J.-D. Brion and M. Alami, Org. Lett., 2012, 14, 1496.
8. R. Shang and L. Liu, Sci. China. Chem., 2011, 54, 1670.
9. (a) D. Alberico, M. E. Scott and M. Lautens, Chem. Rev., 2007,
107, 174; (b) L. Ackermann, R. Vicente and A. R. Kapdi, Angew.
Chem. Int. Ed., 2009, 48, 9792.
disfavoured as no significant drop in product yield was noticed
when different radical scavengers were examined.16 In
accordance to these observations, along with recent literature
reports,18 a plausible mechanistic cycle is proposed. First,
ligated copper forms aryl-copper intermediate via
decarboxylation.
Then, base assisted metalation of
heteroarene with aryl-copper species may lead to either Cu(I)
intermediate (pathway A) or Cu(II) intermediate (pathway B)
by instantaneous oxidation. This Cu(I)/Cu(II) intermediate can
undergo reversible sluggish oxidation to generate aryl-Cu(III)
intermediate followed by immediate reductive elimination to
provide desired direct C‒H arylated product (Scheme 3).
Although the exact role of oxygen is not clear, we believe it is
mainly involved in formation of aryl-Cu(III) species.19
10. (a) S. Zhao, Y.-J. Liu, S.-Y. Yan, F.-J. Chen, Z.-Z. Zhang and B.-F.
Shi, Org. Lett., 2015, 17, 3338; (b) L. Chen, L. Ju, K. A. Bustin and
J. M. Hoover, Chem. Commun., 2015, 51, 15059.
11. (a) J. Cornella, P. Lu and I. Larrosa, Org. Lett., 2009, 11, 5506; (b)
F. Zhang and M. F. Greaney, Angew. Chem. Int. Ed., 2010, 49,
2768; (c) K. Xie, Z. Yang, X. Zhou, X. Li, S. Wang, Z. Tan, X. An and
C.-C. Guo, Org. Lett., 2010, 12, 1564; (d) J. Zhou, P. Hu, M.
Zhang, S. Huang, M. Wang and W. Su, Chem. Eur. J., 2010, 16,
5876; (e) H. Zhao, Y. Wei, J. Xu, J. Kan, W. Su and M. Hong, J.
Org. Chem., 2011, 76, 882; (f) S. Seo, M. Slater and M. F.
Greaney, Org. Lett., 2012, 14, 2650; (g) K. Yang, C. Zhang, P.
Wang, Y. Zhang and H. Ge, Chem. Eur. J., 2014, 20, 7241; (h) G.
Shi, C. Shao, S. Pan, J. Yu and Y. Zhang, Org. Lett., 2015, 17, 38;
(i) J. Kan, S. Huang, J. Lin, M. Zhang and W. Su, Angew. Chem.
Int. Ed., 2015, 54, 2199; (j) Y. Zhang, H. Zhao, M. Zhang and W.
Su, Angew. Chem. Int. Ed., 2015, 54, 3817.
In summary, we have developed a useful protocol with a simple
copper/1,10-phen based system in presence of molecular oxygen as
the sole-oxidant for aryl-heteroaryl cross coupling employing
electron deficient benzoic acids. This method is advantageous for
its wide tolerance towards different heterocycles bearing one or
two heteroatoms under relatively milder condition. Mechanistic
understanding towards developing direct C‒H arylation by copper
are currently ongoing in our group.
12. P. Hu, M. Zhang, X. Jie and W. Su, Angew. Chem. Int. Ed., 2012,
51, 227.
13. (a) M. Nilsson, Acta Chem. Scand, 1966, 20, 423; (b) A.
Cairncross, J. R. Roland, R. M. Henderson and W. A. Sheppard, J.
Am. Chem. Soc., 1970, 92, 3187; (c) T. Cohen and R. A.
Schambach, J. Am. Chem. Soc., 1970, 92, 3189; (d) L. J. Goossen,
F. Manjolinho, B. A. Khan and N. Rodríguez, J. Org. Chem., 2009,
74, 2620.
This activity is supported by SERB, India (EMR/2014/000164).
Financial support received from UGC India (T.P.) and IIT-B (S.S.) is
gratefully acknowledged.
14. (a) L. J. Goossen, W. R. Thiel, N. Rodríguez, C. Linder and B.
Melzer, Adv. Synth. Catal., 2007, 349, 2241; (b) L. J. Goossen, N.
Rodríguez, C. Linder, P. P. Lange and A. Fromm, Chem. Cat.
Chem., 2010, 2, 430.
15. (a) H.-Q. Do and O. Daugulis, J. Am. Chem. Soc., 2007, 129,
12404; (b) O. Daugulis, H.-Q. Do and D. Shabashov, Acc. Chem.
Res., 2009, 42, 1074; (c) H.-Q. Do and O. Daugulis, J. Am. Chem.
Soc., 2011, 133, 13577; (d) S. Guin, T. Ghosh, S. K. Rout, A.
Banerjee and B. K. Patel, Org. Lett., 2011, 13, 5976; (e) A. Gogoi,
S. Guin, S. K. Rout and B. K. Patel, Org. Lett., 2013, 15, 1802; (f)
M. Ghosh, S. Mishra, K. Monir and A. Hajra, Org. Biomol. Chem.,
2015, 13, 309.
16. See the Supporting Information for detailed description.
17. Q. Song, Q. Feng and M. Zhou, Org. Lett., 2013, 15, 5990.
18. (a) A. E. Wendlandt, A. M. Suess and S. S. Stahl, Angew. Chem.
Int. Ed., 2011, 50, 11062; (b) L. Chu and F.-L. Qing, J. Am. Chem.
Soc., 2012, 134, 1298; (c) A. M. Suess, M. Z. Ertem, C. J. Cramer
and S. S. Stahl, J. Am. Chem. Soc., 2013, 135, 9797.
Notes and references
1. (a) R. C. Koehler, D. A. Wilson, M. C. Rogers and R. J. Traystman,
J. Pharmacol. Exp. Ther., 1985, 233, 327; (b) R. E. West Jr, S. M.
Williams, H. S. She, N. I. Carruthers, R. W. Egan and M. Motasim
Billah, Prostaglandins, 1997, 54, 891; (c) R. Zucchi and S. Ronca-
Testoni, Pharmacol. Rev., 1997, 49, 1; (d) E. Barrett-Connor,
Ann. N.Y. Acad. Sci., 2001, 949, 295; (e) C. R. Overk, K.-W. Peng,
R. T. Asghodom, I. Kastrati, D. D. Lantvit, Z. Qin, J. Frasor, J. L.
Bolton and G. R. J. Thatcher, Chem. Med. Chem., 2007, 2, 1520;
(f) C. E. Bulawa, S. Connelly, M. DeVit, L. Wang, C. Weigel, J. A.
Fleming, J. Packman, E. T. Powers, R. L. Wiseman, T. R. Foss, I. A.
Wilson, J. W. Kelly and R. Labaudinière, Proc. Natl. Acad. Sci.
USA, 2012, 109, 9629.
2. (a) A. K. Verma, T. Kesharwani, J. Singh, V. Tandon and R. C.
Larock, Angew. Chem. Int. Ed., 2009, 48, 1138; (b) S. Park, J.
Jung and E. J. Cho, Eur. J. Org. Chem., 2014, 4148.
3. B. Martín-Matute, K. J. Szabó and T. N. Mitchell, in Metal-
Catalyzed Cross-Coupling Reactions and More, eds. A. d.
Meijere, S. Brase and M. Oestreich, Wiley-VCH Verlag GmbH &
Co. KGaA, 2014, pp. 423.
19. (a) A. E. King, L. M. Huffman, A. Casitas, M. Costas, X. Ribas and
S. S. Stahl, J. Am. Chem. Soc., 2010, 132, 12068; (b) A. Casitas
and X. Ribas, Chem. Sci., 2013, 4, 2301.
4. M. Nakamura, A. Hajra, K. Endo and E. Nakamura, Angew.
Chem. Int. Ed., 2005, 44, 7248.
5. (a) L. J. Goossen, N. Rodríguez and K. Goossen, Angew. Chem.
Int. Ed., 2008, 47, 3100; (b) N. Rodriguez and L. J. Goossen,
Chem. Soc. Rev., 2011, 40, 5030; (c) W. I. Dzik, P. P. Lange and L.
J. Goossen, Chem. Sci., 2012, 3, 2671; (d) P. Hu, Y. Shang and W.
Su, Angew. Chem. Int. Ed., 2012, 51, 5945; (e) C. J. Gartshore
and D. W. Lupton, Angew. Chem. Int. Ed., 2013, 52, 4113.
6. (a) L. J. Goossen, G. Deng and L. M. Levy, Science, 2006, 313,
662; (b) L. J. Goossen, N. Rodriguez and C. Linder, J. Am. Chem.
Soc., 2008, 130, 15248; (c) L. J. Goossen, B. Zimmermann and T.
Knauber, Angew. Chem. Int. Ed., 2008, 47, 7103; (d) S. Bhadra,
W. I. Dzik and L. J. Goossen, J. Am. Chem. Soc., 2012, 134, 9938.
4 | J. Name., 2013, 00, 1-4
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins