Nickel-catalyzed decarboxylative cross-coupling of perfluorobenzoates with aryl halides and sulfonates

Article abstract of DOI:10.1021/acs.orglett.5b00241

A Ni-catalyzed method for the coupling of perfluorobenzoates with aryl halides and pseudohalides is described. Aryl iodides, bromides, chlorides, triflates, and tosylates participate in these transformations to afford the products in good yields. Penta-, tetra-, and trifluorinated biaryl compounds are obtained using these newly developed Ni-catalyzed decarboxylative cross-coupling reactions.

Full text of DOI:10.1021/acs.orglett.5b00241

Letter
pubs.acs.org/OrgLett
Nickel-Catalyzed Decarboxylative Cross-Coupling of
Perfluorobenzoates with Aryl Halides and Sulfonates
Logan W. Sardzinski, William C. Wertjes, Abigail M. Schnaith, and Dipannita Kalyani*
Department of Chemistry, St. Olaf College, 1520 St. Olaf Avenue, Northfield, Minnesota 55057, United States
S
* Supporting Information
ABSTRACT: A Ni-catalyzed method for the coupling of
perfluorobenzoates with aryl halides and pseudohalides is
described. Aryl iodides, bromides, chlorides, triflates, and
tosylates participate in these transformations to afford the
products in good yields. Penta-, tetra-, and trifluorinated biaryl
compounds are obtained using these newly developed Ni-catalyzed decarboxylative cross-coupling reactions.
Scheme 1. Plausible Mechanism for Ni-Catalyzed
Decarboxylative Cross-Coupling
ecarboxylative cross-couplings are an attractive strategy
Dfor the construction of biaryl bonds because they
constitute a greener and more economical alternative to
traditional cross-coupling reactions.1 These transformations
entail the coupling of aromatic carboxylic acids with aryl halides
(or pseudohalides) or organometallic reagents. The carboxylic
acids employed in these reactions are bench stable and
compatible with multistep reaction sequences in either native
or latent form (e.g., from esters, amides, etc.). Furthermore,
structurally diverse carboxylic acids are often inexpensive and
are prevalent in abundant biomass feedstocks. Additionally, the
use of carboxylic acids obviates the formation of stoichiometric
organometallic byproducts that are formed in Suzuki−Miyaura,
Stille, Kumada, and Negishi reactions.1,2
Striking the optimal balance between the relative rates of
decarboxylation and steps (i) and (ii) of the catalytic cycle is
critical to minimize the undesired homocoupling of aryl−metal
complexes I or of Ar′M (generated from Ar′CO2M). A well-
established challenge for decarboxylative cross-coupling reac-
tions is the high temperature required for the extrusion of CO2,
which can lead to unwanted side reactions.1 As such,
perfluorobenzoates were chosen for the initial studies because
these substrates are known to extrude CO2 at moderate
temperatures.12 Herein, we describe a method for the Ni-
catalyzed intermolecular coupling of benzoates with aryl
halides, triflates, and tosylates. Notably, the fluorinated biaryl
products of these newly developed transformations find
important applications in pharmaceutical and material
sciences.13
Our studies commenced with the investigation of reaction
parameters for the cross-coupling of 4-iodoanisole 1-I with
pentafluorophenyl potassium carboxylate (A). The use of
Ni(COD)2 was explored in the presence of phosphine ligands
used previously in analogous Pd-catalyzed transformations.12 As
shown in Table 1, PtBu3 is more effective than PCy3 for these
reactions (entries 1 and 2). Interestingly, 1a is obtained in
comparable yields in the absence of any ligands (entry 3). In
The majority of known methods for the decarboxylative
biaryl synthesis utilize precious metal Pd catalysts.1,3,4 In recent
years, a growing impetus for environmental and economic
sustainability has sparked a desire for the replacement of noble
metals such as Pd with their earth-abundant and less expensive
counterparts in catalytic transformations.5 To this end, a few
examples of Cu-catalyzed decarboxylative biaryl bond for-
mations have surfaced in the literature.6,7 In contrast, examples
of similar Ni-catalyzed reactions remain sparse.8,9 To the best of
our knowledge, no examples of biaryl synthesis via cross-
coupling of benzoic acid derivatives with aryl halides (or
pseudohalides) using Ni catalysis have been disclosed.
Importantly, a broader range of aromatic electrophiles are
known to participate in cross-couplings using Ni catalysis (e.g.,
sulfonates, carboxylates, carbamates, and carbonates) instead of
using Pd (sulfonates) or Cu (halides) catalysis.1,2,5,6,10 As such,
the successful implementation of broad and generally applicable
Ni-catalyzed decarboxylative reactions will significantly broaden
the scope of electrophiles for decarboxylative couplings. A
plausible mechanism for the proposed Ni-catalyzed decarbox-
ylative coupling is depicted in Scheme 1. It involves (i)
oxidative addition of Ni0 into Ar−X, (ii) transmetalation of
Ar′−[M] generated via decarboxylation onto the aryl Ni
intermediate (I), and (iii) reductive elimination to release the
product and regenerate the Ni0 catalyst.1,11
Received: January 25, 2015
Published: February 20, 2015
© 2015 American Chemical Society
1256
DOI: 10.1021/acs.orglett.5b00241
Org. Lett. 2015, 17, 1256−1259

Organic Letters
Letter
electron-deficient aryl iodides afford the desired products in
good yields. ortho-Substituted and heterocyclic iodides also
participate effectively in these decarboxylative couplings. The
transformation is compatible with a number of synthetically
versatile functional groups including ethers, nitriles, and esters.
Electronically varied aryl bromides and chlorides also couple
with salt A to afford the corresponding biaryl products in
modest to good yields (Scheme 3). In general, the efficiency of
these reactions is attenuated relative to those with aryl iodides.
Table 1. Optimization of Decarboxylative Cross-Coupling
ab
,
entry
X
ligand
temp (°C)
yield of 1a (%)
1
2
3
I
PCy3HBF4
PtBu3HBF4
none
140
140
140
140
140
140
140
140
160
160
140
140
140
140
140
58
79
72
0
I
I
a
c
4
I
PtBu3HBF4
Scheme 3. Scope of Aryl Bromides and Chlorides
5
6
7
8
9
Br
Br
Br
Br
Br
Br
Cl
Cl
Cl
Cl
Cl
none
6
PCy3HBF4
PtBu3HBF4
CM-Phos
CM-Phos
CM-Phos
CM-Phos
PtBu3HBF4
PCy3HBF4
DPPF
32
13
55
62
0
c
10
11
12
13
14
31
0
<2
51
0
c
15
DPPF
a
General conditions: Ni(COD)2 (0.1 equiv), ligand (0.2 equiv),
b
diglyme, 20 h. Calibrated GC yields against hexadecane as the
internal standard. General conditions but with no Ni(COD)2.
c
contrast, the use of a ligand is essential to obtain synthetically
useful yields of 1a from the reaction of aryl bromides and
chlorides. Among the ligands screened, CM-Phos (2-[2-
(dicyclohexylphosphino)phenyl]-1-methyl-1H-indole) and
DPPF (diphenylphosphinoferrocene) afford the highest yields
of the desired products from the reaction of 1-Br and 1-Cl,
respectively (entries 9 and 14). Importantly, no product is
obtained with any of the halides (1-I, 1-Br, or 1-Cl) in the
absence of Ni(COD)2 (entries 4, 10, and 15).14
a
Isolated yields are given with GC yields in parentheses (calibrated
b
against hexadecane as the internal standard). Conditions A:
Ni(COD)2 (0.1 equiv), CM-Phos (0.2 equiv), diglyme, 160 °C.
c
Conditions B: Ni(COD)2 (0.1 equiv), DPPF (0.125 equiv), diglyme,
d
e
140 °C. Conditions B with DPPF (0.2 equiv). Conditions A but
f
with PtBu3HBF4 as ligand at 120 °C. Conditions A at 140 °C.
As detailed in Scheme 2, the optimal conditions for the
coupling using 1-I (Table 1, entry 3) can be applied toward the
use of other aryl iodides. Electron-rich, electron-neutral, and
The reaction of pentafluoro salt A with phenolic electrophiles
was next examined. These electrophiles avoid the production of
undesired halide-containing byproducts and hence are more
environmentally desirable.10,15 Scheme 4 illustrates a prelimi-
nary scope for the coupling of aryl tosylates with salt A.
Electron-neutral, electron-deficient, and moderately electron-
rich tosylates couple with A to afford the products in modest to
good yields. Additionally, aryl triflates afford the products in
yields comparable to those obtained using the corresponding
aryl tosylates.
a
Scheme 2. Scope of Aryl Iodides
Having explored the preliminary scope for the coupling of
aryl halides and tosylates with salt A, we next examined the
reaction of aryl electrophiles with other perfluorobenzoates. As
shown in Scheme 5, both tetrafluoro- and trifluorophenyl
carboxylates couple with electron-rich and electron-deficient
iodides to afford the desired products with comparable
efficiencies (1b−d and 6b−d). However, the efficiency of the
reactions using the trifluorobenzoate salt D is lower than that
with tetrafluoro salts B and C. The reactions of the ester-
substituted aryl bromides and tosylates with salt C were also
explored and compared to the analogous reactions with A. The
aryl bromide coupling using the pentafluoro salt A affords
product 6a (63%) in higher yield than product 6c (31%) using
tetrafluoro salt C (Schemes 3 and 5). However, when the p-
tosylethylbenzoate is used, 6c (70%, Scheme 5) is obtained in
a
Conditions: Ni(COD)2 (0.1 equiv), diglyme, 120 °C. Isolated yields
are given with GC yields in parentheses (calibrated against hexadecane
as the internal standard). General conditions but at 140 °C.
b
1257
DOI: 10.1021/acs.orglett.5b00241
Org. Lett. 2015, 17, 1256−1259

Organic Letters
Letter
Scheme 4. Scope of Cross-Coupling Using Aryl Triflates and
Tosylates
Scheme 6. Cross-Couplings with 4-Iodochloride and 4-
Iodotosylate
a
formation using Ni-catalyzed decarboxylative cross-coupling
reactions.
ASSOCIATED CONTENT
* Supporting Information
Experimental details and spectroscopic and analytical data for
new compounds. This material is available free of charge via the
Internet at http://pubs.acs.org.
■
a
Conditions: Ni(COD)2 (0.1 equiv), DPPF (0.125 equiv), diglyme,
S
140 °C. Isolated yields are given with GC yields in parentheses
(calibrated against hexadecane as the internal standard). General
conditions but with 2.5 equiv of A.
b
a
Scheme 5. Scope of Perfluorobenzoates
AUTHOR INFORMATION
Corresponding Author
■
*E-mail: kalyani@stolaf.edu.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
The authors gratefully acknowledge St. Olaf College, National
Institutes of Health (R15 GM107892), and the American
Chemical Society Petroleum Research Fund (PRF#52224-
UNI3) for funding this research.
REFERENCES
■
(1) (a) Gooßen, L. J.; Rodríguez, N.; Gooßen, K. Angew. Chem., Int.
Ed. 2008, 47, 3100−3120. (b) Weaver, J. D.; Recio, A.; Grenning, A. J.;
Tunge, J. A. Chem. Rev. 2011, 111, 1846−1913. (c) Rodríguez, N.;
Gooßen, L. J. Chem. Soc. Rev. 2011, 40, 5030−5048. (d) Dzik, W. I.;
Lange, P. P.; Gooßen, L. J. Chem. Sci. 2012, 3, 2671−2678.
(e) Gooßen, L. J.; Gooßen, K. Top. Organomet. Chem. 2013, 44,
121−141. (f) Park, K.; Lee, S. RSC Adv. 2013, 3, 14165−14182.
(2) (a) Metal-Catalyzed Cross-Coupling Reactions, 2nd ed.; de Meijere,
A., Diederich, F., Eds.; Wiley-VCH: Weinheim, Germany, 2004.
(b) Seechurn, C. C. C. J.; Kitching, M. O.; Colacot, T. J.; Snieckus, V.
Angew. Chem., Int. Ed. 2012, 51, 5062−5085.
(3) For Pd-catalyzed decarboxylative biaryl bond formation, see:
(a) Hu, P.; Zhang, M.; Jie, X.; Su, W. Angew. Chem., Int. Ed. 2012, 51,
227−231. (b) Zhang, F.-Z.; Greaney, M. F. Angew. Chem., Int. Ed.
2010, 49, 2768−2771. (c) Xie, K.; Yang, Z.; Zhou, X.; Li, X.; Wang, S.;
Tan, Z.; An, X.; Guo, C.-C. Org. Lett. 2010, 12, 1564−1567. (d) Wang,
C.; Piel, I.; Glorius, F. J. Am. Chem. Soc. 2009, 131, 4194−4195.
(e) Cornella, J.; Lu, P.; Larrosa, I. Org. Lett. 2009, 11, 5506−5509.
(f) Voutchkova, A.; Coplin, A.; Leadbeater, N. E.; Crabtree, R. H.
Chem. Commun. 2008, 6312−6314.
(4) For Rh- and Ru-catalyzed reactions, see: (a) Neely, J. M.; Rovis,
T. J. Am. Chem. Soc. 2014, 136, 2735−2738. (b) Zhang, J.; Liu, J.-F.;
Ugrinov, A.; Pillai, A. F. X.; Sun, Z.-M.; Zhao, P. J. Am. Chem. Soc.
2013, 135, 17270−17273. (c) Wang, J.; Liu, B.; Zhao, H.; Wang, J.
Organometallics 2012, 31, 8598−8607. (d) Sun, Z. M.; Zhang, J.; Zhao,
P. Org. Lett. 2010, 12, 992−995. (e) Austeri, M.; Linder, D.; Lacour, J.
Adv. Synth. Catal. 2010, 352, 3339−3347. (f) Austeri, M.; Linder, D.;
Lacour, J. Chem.Eur. J. 2008, 14, 5737−5741. (g) Burger, E. C.;
Tunge, J. A. Org. Lett. 2004, 6, 2603−2605.
a
Conditions: Ni(COD)2 (0.1 equiv), PtBu3HBF4 (0.2 equiv), diglyme,
140 °C. Isolated yields are given with GC yields in parentheses
(calibrated against hexadecane as the internal standard). General
conditions but with DPPF as ligand (0.125 equiv). General conditions
but with CM-Phos as ligand at 160 °C. General conditions but at 160
b
c
d
°C.
higher yield than 6a (53%, Scheme 4), suggesting that the
leaving group in the electrophile could impact the relative
reactivity toward coupling with various carboxylates.1
As illustrated in Table 1, aryl iodides participate effectively in
these transformations in the absence of a ligand. The superior
reactivity of iodides in the absence of ligands can be exploited
strategically in sequential cross-couplings using substrates such
as 12-I and 13-I (Scheme 6). For example, reaction of 12-I and
13-I with salt A affords products 12a and 13a, respectively, via
cross-coupling at the C−I bond. The C−Cl and C−OTs bonds
in 12a and 13a can be elaborated using myriad known
transformations of aryl halides and tosylates for the synthesis of
diverse biaryl motifs.2
In summary, the first example of Ni-catalyzed decarboxylative
cross-coupling of aryl halides and pseudohalides with aromatic
carboxylates is described. These studies set the stage for further
explorations toward elucidating the scope of biaryl bond
1258
DOI: 10.1021/acs.orglett.5b00241
Org. Lett. 2015, 17, 1256−1259

Organic Letters
Letter
(5) (a) Nakamura, E.; Hatakeyama, T.; Ito, S.; Ishizuka, K.; Ilies, L.;
Nakamura, M. Org. React. 2013, 83, 1−209. (b) Yamaguchi, J.; Muto,
K.; Itami, K. Eur. J. Org. Chem. 2013, 1, 19−30. (c) Tekale, S. U.;
Jadhav, V. B.; Pagore, V. P.; Kauthale, S. S.; Gaikwad, D. D.; Pawar, R.
P. Mini-Rev. Org. Chem. 2013, 10, 281−301. (d) Cahiez, G.; Moyeux,
A. Chem. Rev. 2010, 110, 1435−1462.
(6) For Cu-catalyzed decarboxylative biaryl bond formation, see:
(a) Ponpandian, T.; Muthusubramanian, S. Tetrahedron Lett. 2012, 53,
4248−4252. (b) Shang, R.; Fu, Y.; Wang, Y.; Xu, Q.; Yu, H.-Z.; Liu, L.
Angew. Chem., Int. Ed. 2009, 48, 9350−9354.
(7) For Fe-catalyzed decarboxylative cross-couplings, see: (a) Rong,
G.; Liu, D.; Lu, L.; Yan, H.; Zheng, Y.; Chen, J.; Mao, J. Tetrahedron
2014, 70, 5033−5037. (b) Zhao, J.; Zhou, W.; Han, J.; Li, G.; Pan, Y.
Tetrahedron Lett. 2013, 54, 6507−6510. (c) Zhao, J.; Fang, H.; Han, J.;
Pan, Y. Beilstein J. Org. Chem. 2013, 9, 1718−1723. (d) Yang, H.; Yan,
H.; Sun, P.; Zhu, Y.; Lu, L.; Liu, D.; Rong, G.; Mao, J. Green Chem.
2013, 15, 976−981. (e) Bi, H.-P.; Chen, W.-W.; Liang, Y.-M.; Li, C.-J.
Org. Lett. 2009, 11, 3246−3249.
(8) For Ni-catalyzed decarboxylative cross-coupling for construction
of bonds other than the biaryl bond, see: (a) Yang, K.; Zhang, C.;
Wang, P.; Zhang, Y.; Ge, H. Chem.Eur. J. 2014, 20, 7241−7244.
(b) Wu, Y.; Liu, L.; Yan, K.; Xu, P.; Gao, Y.; Zhao, Y. J. Org. Chem.
2014, 79, 8118−8127. (c) Zuo, Z.; Ahneman, D. T.; Chu, L.; Terrett,
J. A.; Doyle, A. G.; MacMillan, D. W. C. Science 2014, 345, 437−440.
(d) Choe, J.; Yang, J.; Park, K.; Palani, T.; Lee, S. Tetrahedron Lett.
2012, 53, 6908−6912.
(9) For Ni-catalyzed decarbonylative and decarboxylative C−H
arylation, see: (a) Yang, K.; Wang, P.; Zhang, C.; Kadi, A. A.; Fun, H.
K.; Zhang, Y.; Lu, H. Eur. J. Org. Chem. 2014, 34, 7586−7589.
(b) Amaike, K.; Muto, K.; Yamaguchi, J.; Itami, K.; Zhang, C.; Wang,
P.; Zhang, Y.; Ge, H. J. Am. Chem. Soc. 2012, 134, 13573−13576.
(10) (a) Mesganaw, T.; Garg, N. K. Org. Process Res. Dev. 2013, 17,
29−39. (b) So, C. M.; Kwong, F. Y. Chem. Soc. Rev. 2011, 40, 4963−
4972. (c) Rosen, B. M.; Quasdorf, K. W.; Wilson, D. A.; Zhang, N.;
Resmerita, A.-M.; Garg, N. K.; Percec, V. Chem. Rev. 2011, 111, 1346−
1416. (d) Li, B.-J.; Yu, D.-G.; Sun, C.-L.; Shi, Z.-J. Chem.Eur. J.
2011, 17, 1728−1759. (e) Kozhushkov, S. I.; Potukuchi, H. K.;
Ackermann, L. Catal. Sci. Technol. 2013, 3, 562−571. (f) Yu, D.-G.; Li,
B.-J.; Shi, Z.-J. Acc. Chem. Res. 2010, 43, 1486−1495. (g) Antoft-Finch,
A.; Blackburn, T.; Snieckus, V. J. Am. Chem. Soc. 2009, 131, 17750−
17752.
(11) Fromm, A.; van Wullen, C.; Hackenberger, D.; Gooßen, L. J. J.
̈
Am. Chem. Soc. 2014, 136, 10007−10023.
(12) Shang, R.; Xu, Q.; Jiang, Y.-Y.; Wang, Y.; Liu, L. Org. Lett. 2010,
12, 1000−1003.
(13) (a) Okamoto, T.; Nakahara, K.; Saeki, A.; Seki, S.; Oh, J. H.;
Akkerman, H. B.; Bao, Z.; Matsuo, Y. Chem. Mater. 2011, 23, 1646−
1649. (b) Amii, H.; Uneyama, K. Chem. Rev. 2009, 109, 2119−2183.
(c) Babudri, F.; Farinola, G. M.; Naso, F.; Ragni, R. Chem. Commun.
2007, 1003.
(14) NiBr2(DME) and/or NiCl2(PCy3)2 can be used instead of
Ni(COD)2 for iodides, bromides, and tosylates. See Table 1 in
Supporting Information for details.
(15) (a) Gooßen, L. J.; Rodríguez, N.; Linder, C. J. Am. Chem. Soc.
2008, 130, 15248. (b) Gooßen, L. J.; Rodríguez, N.; Lange, P. P.
Angew. Chem., Int. Ed. 2010, 49, 1111.
1259
DOI: 10.1021/acs.orglett.5b00241
Org. Lett. 2015, 17, 1256−1259