Nickel-catalyzed site-selective alkylation of unactivated C(sp 3)-H bonds

Article abstract of DOI:10.1021/ja413131m

The direct alkylation of unactivated sp³ C-H bonds of aliphatic amides was achieved via nickel catalysis with the assist of a bidentate directing group. The reaction favors the C-H bonds of methyl groups over the methylene C-H bonds and tolerates various functional groups. Moreover, this reaction shows a predominant preference for sp³ C-H bonds of methyl groups via a five-membered ring intermediate over the sp² C-H bonds of arenes in the cyclometalation step.

Full text of DOI:10.1021/ja413131m

Communication
pubs.acs.org/JACS
Nickel-Catalyzed Site-Selective Alkylation of Unactivated C(sp3)−H
Bonds
Xuesong Wu,† Yan Zhao,† and Haibo Ge*,†,‡,§
†Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202
United States
§
‡Institute of Chemistry and Biomedical Sciences and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing
210093, P. R. China
S
* Supporting Information
multisubstituted acid derivatives, the important synthetic
ABSTRACT: The direct alkylation of unactivated sp3 C−
intermediates or structural units in biologically active natural
products and medicinal compounds.14
H bonds of aliphatic amides was achieved via nickel
catalysis with the assist of a bidentate directing group. The
To verify the proposed strategy, nickel-catalyzed direct
reaction favors the C−H bonds of methyl groups over the
alkylation of 2-ethyl-2-methyl-N-(quinolin-8-yl)pentanamide
methylene C−H bonds and tolerates various functional
(1a) with iodopentane was carried out (Table 1). After an initial
groups. Moreover, this reaction shows a predominant
preference for sp3 C−H bonds of methyl groups via a five-
screening of the catalyst, the alkylated product 2a was obtained in
membered ring intermediate over the sp2 C−H bonds of
arenes in the cyclometalation step.
63% yield by using catalytic amounts of Ni(acac)2 and PPh3 and
excess Cs2CO3 in toluene under atmosphere of N2 (entry 5). It
was also noticed that this reaction showed high site selectivity by
a
Table 1. Optimization of Reaction Conditions
n the last couple of decades, Ni-catalyzed cross-couplings are
1
Iof great interest to organic chemists.
Along with the
extensively studied cross-coupling reactions of aryl halides and
pseudohalides, Ni-catalyzed cross-couplings of primary, secon-
dary, and tertiary alkyl halides and surrogates have also been well
established.1f,j,2 Moreover, this first-row transition metal is also
capable of catalyzing less reactive electrophiles, such as ethers
and phenols, which distinguishes this metal from the second- and
third-row elements Pd and Pt in the d10 group.1g,i,3
Ni source
(10 mol %)
yield
b
entry
ligand (mol %)
base (equiv)
(%)
1
2
Ni(OTf)2
Ni(COD)2
NiBr2
PPh3 (20)
PPh3 (20)
PPh3 (20)
PPh3 (20)
PPh3 (20)
−
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
<5
<5
Although less studied, Ni-catalyzed cross-couplings via an sp2
C−H functionalization process have also been documented.4
Early studies showed that this process could be well performed
with a catalytic Ni0 species on substrates with an acidic C−H
bond, such as pyridine,5 perfluorobenzene,6 and azole deriva-
tives,7 and it is believed that the catalytic cycle is initiated by
oxidative addition of Ni0 to the acidic C−H bond. Additionally,
NiII-catalyzed direct arylation of azole derivatives was also
demonstrated.8 In this case, a NiII species acts as an electrophile
for aromatic substitution reaction of azoles. Recently, Ni0-
catalyzed direct funtionalization of benzene derivatives has also
been developed.9 Furthermore, inspired by the reports from the
Daugulis’ group, the PdII-catalyzed direct functionalization of
unactivated C−H bonds via a bidentate directing group-assisted
process,4b,10 NiII-catalyzed direct alkylation of benzamide
derivatives has also been demonstrated very recently.11 Addi-
tionally, a Ni0-catalyzed cycloaddition reaction of foramides with
alkynes was reported via in situ sp3 C−H bond activation.12
However, to date, ligand-controlled Ni-catalyzed cross-couplings
via an sp3 C−H functionalization process have not been
discovered. It is believed that this process is feasible with the
aid of a bidentate directing group, which will lead to the site-
selective functionalization on sp3 carbons.13 If successful, this
process will provide a complementary approach to access α-
3
28
4
NiCl2·6H2O
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(acac)2
41
5
63
6
10
7
P(2-furyl)3 (20) Cs2CO3 (5.0)
71
8
PCy3 (20)
dppe (10)
dppp(10)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
Cs2CO3 (5.0)
K2CO3 (5.0)
Na2CO3 (5.0)
K3PO4 (5.0)
Cs2CO3 (3.0)
82
9
71
10
11
12
13
14
15
16
17
69
xantphos (10)
BINAP (10)
dppbz(10)
dppbz(10)
dppbz(10)
dppbz(10)
dppbz(10)
79
74
c
89(86)
70
<5
<5
65
a
Reaction conditions: 1a (0.3 mmol), Ni source (10 mol %), ligand,
b
base, N2 (1 atm), 1.2 mL of toluene, 150 °C, 24 h. Yields and
conversions are based on 1a, determined by 1H NMR using
c
dibromomethane as the internal standard. Isolated yields. Dppbz =
1,2-bis(diphenylphosphino)benzene.
Received: December 25, 2013
© XXXX American Chemical Society
A
dx.doi.org/10.1021/ja413131m | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX

Journal of the American Chemical Society
Communication
favoring the methyl group over the methylene groups, which is
believed to be arisen from the steric effect. Additionally, the
formation of a five-membered ring intermediate in the
cyclometalation step is preferred over the six- or seven-
membered ring intermediates since the alkylation of the C−H
bonds of methyl groups on the ethyl or propyl group was not
observed. Further optimization showed that this reaction was
improved by using the bidentate ligand dppbz (entry 13).
Additionally, the reaction could also be effectively performed in
other solvents (see Supporting Information).
bond functionalization was disfavored in the presence of a
competing sp2 C−H bond. As expected, with two methyl groups
on the α-position of the amide, both mono- and dialkylated
products were observed, favoring the mon-alkylation (2j−m).
Furthermore, the 2,2-dimethyl-substituted propanamide pro-
vided three products with the mono- and dialkylated products as
the major isomers (2n). It was also noticed that a tertiary α-
carbon is necessary for this process to reach an efficient
cyclometalation since amides 3−6 failed to this reaction. In
addition, cyclobutanecaroxamide 7 did not provide the desired
product. As suggested by the report from Nakamura’s group, the
CH3−C−C(O) bond angle of 7 is much wider than its
cyclopentyl or cyclohexyl derivative,15 and thus the cyclo-
metalation of this substrate with a NiII species is less feasible.
Furthermore, 2,2-diethyl-N-(quinolin-8-yl)butanamide (8) also
failed to provide any C-alkylated products on either the primary
or secondary carbon.
With the optimized conditions in hand, the scope of amides
was studied. As shown in Table 2, 2,2-disubstituted propana-
a b
,
Table 2. Scope of Aliphatic Amides
Next, we carried out the substrate scope study on alkyl halides
(Table 3). As expected, linear alkyl halides showed great
a b
,
Table 3. Scope of Alkyl Halides
a
Reaction conditions: 1 (0.3 mmol), alkyl halide (5.0 equiv),
Ni(acac)2 (10 mol %), dppbz (10 mol %), Cs2CO3 (5.0 equiv), N2
b
c
(1 atm), 1.2 mL toluene, 150 °C, 24 h. Isolated yield. With CsI (5.0
d
e
equiv). Alkyl iodide. Alkyl bromide with CsI (5.0 equiv).
a
Reaction conditions: 1 (0.3 mmol), iodopentane (5.0 equiv),
Ni(acac)2 (10 mol %), dppbz (10 mol %), Cs2CO3 (5.0 equiv), N2
b
(1 atm), 1.2 mL toluene, 150 °C, 12−24 h. Isolated yield. Q = 8-
compatibility with the reaction conditions, and this reaction
tolerated a variety of functional groups, such as the alkene, cyano,
ester, and trifluoromethyl groups (2a−y). It was also found that
alkyl iodides could be replaced with alkyl bromides or chlorides
with the addition of CsI. Furthermore, there is an apparent steric
effect for this reaction since both isopropyl and isobutyl iodides
failed to give the desired products. In addition, benzylic and
allylic halides were not compatible with the current reaction
conditions. Unfortunately, secondary alkyl halides and benzyl
bromide failed to provide the desired products, presumably due
to the steric effect or the unstability of the intermediate.
quinolinyl.
mides bearing both the linear and cyclic chains provided the
desired products in good to excellent yields (2a−i). Surprisingly,
with the 2-phenyl-substituted substrates, the reaction showed a
predominant preference for the sp3 C−H bonds of methyl group
over the sp2 C−H bonds of phenyl group (2e and 2f), indicating
that in the metalation step, a five-membered intermediate should
be favored than a six-membered intermediate. It is noteworthy
that in the Pd-catalyzed direct alkylation of amides, sp3 C−H
B
dx.doi.org/10.1021/ja413131m | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX

Journal of the American Chemical Society
Communication
On the basis of the above results and the previous reports,11,16
a plausible reaction mechanism is proposed (Scheme 1).
Scheme 2. Deuterium Labeling and Radical Trapping
Experiments
Scheme 1. Proposed Reaction Mechanism
Unexpectedly, the preference for sp3 C−H bonds of methyl
groups via a five-membered ring intermediate in the cyclo-
metalation step was also observed over the sp2 C−H bonds of
arenes via a six-membered ring intermediate, which constitutes a
unique phenomenon of nickel catalysis. The detailed mechanistic
study of this transformation is currently undergoing in our
laboratory.
Coordination of amide 1 to a NiII species followed by a ligand
exchange process under basic conditions generates nickel
complex A, which gives rise to the intermediate B via a reversible
cyclometalation process.17 Oxidative addition of intermediate B
with an alkyl halide followed by reductive elimination generates
the intermediate D,18 which produces the desired product 2
upon protonation and regenerates the NiII species. Alternatively,
the NiIII complex E could be involved in this process by oxidation
of intermediate B with an alkyl radical.19 Reductive elimination of
the intermediate E followed by protonation generates the desired
product 2 and a NiI species. Treatment of the NiI species with an
alkyl halide produces the alkyl radical and NiII species. It is
noteworthy that in the reaction of 1a with 1-iododecane, a small
amount of decene, the β-H eliminated product of the alkylmetal
intermediate, was detected by GC/mass, which indirectly
supports the formation of the intermediate C or E. It should
be mentioned that although this process could potentially begin
with a Ni0 species,9d the extremely low yield of 2a with a catalytic
amount of Ni(COD)2 indicates that the catalytic cycle is unlikely
initiated by a Ni0 species.
To further probe the reaction mechanism, a deuterium-
labeling experiment was carried out, and an apparent isotope
effect was observed [Scheme 2, (1)]. This indicates that the
cyclometalation of amide 1 with a nickel species is the rate-
determining step in the process. Furthermore, a radical trapping
experiment was also carried out, and it was found that the
addition of TEMPO resulted in the decreased yield of this
reaction [Scheme 2, (2)]. Additionally, 2,2,6,6-tetramethyl-1-
(pentyloxy)piperidine (8) was isolated along with the desired
product. Notably, in the absence of a nickel species, this
compound was not produced. On the basis of the above
observations, it is believed that this reaction performed through
the NiII/NiIII catalytic cycle.
ASSOCIATED CONTENT
* Supporting Information
Experimental details and characterization data. This material is
available free of charge via the Internet at http://pubs.acs.org.
■
S
AUTHOR INFORMATION
Corresponding Author
geh@iupui.edu
■
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
The authors gratefully acknowledge financial support for this
research from Indiana University Purdue University Indian-
apolis. The Bruker 500 MHz NMR was purchased using funds
from an NSF-MRI award (CHE-0619254).
REFERENCES
■
(1) For selected recent reviews, see: (a) Metal-Catalyzed Cross-
Coupling Reactions, 2nd ed.; de Meijere, A., Diederich, F., Eds.; Wiley-
VCH: Weinheim, Germany, 2004; Vol. 2. (b) Takahashi, T.; Kanna, K.-i.
Modern Organonickel Chemistry, Wiley-VCH: Weinheim, Germany,
2005, p 41. (c) Negishi, E.-i.; Hu, Q.; Huang, Z.-H.; Wang, G.-W.; Yin,
N. Chemistry of Organozinc Compounds, John Wiley & Sons Ltd.:
Chichester, UK, 2006, p 457. (d) Nakao, Y.; Hiyama, T. Pure Appl.
Chem. 2008, 80, 1097. (e) Denmark, S. E.; Butler, C. R. Chem. Commun.
2009, 20. (f) Phapale, V. B.; Cardenas, D. J. Chem. Soc. Rev. 2009, 38,
1598. (g) Rosen, B. M.; Quasdorf, K. W.; Wilson, D. A.; Zhang, N.;
Resmerita, A.-M.; Garg, N. K.; Percec, V. Chem. Rev. 2011, 111, 1346.
(h) Jana, R.; Pathak, T. P.; Sigman, M. S. Chem. Rev. 2011, 111, 1417.
(i) Mesganaw, T.; Garg, N. K. Org. Process Res. Dev. 2013, 17, 29.
(j) Han, F.-S. Chem. Soc. Rev. 2013, 42, 5270.
In summary, a highly regioselective alkylation of 2,2-
disubstituted propionamide with 8-aminoquinolinyl group as
the amide moiety was developed via a nickel-catalyzed sp3 C−H
bond functionalization process. This reaction shows a great
preference for sp3 C−H bonds of methyl groups over the
methylene C−H bonds with good functional group tolerance.
(2) (a) Netherton, M. R.; Fu, G. C. Adv. Synth. Catal. 2004, 346, 1525.
(b) Guan, B.-T.; Xiang, S.-K.; Wang, B.-Q.; Sun, Z.-P.; Wang, Y.; Zhao,
C
dx.doi.org/10.1021/ja413131m | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX

Journal of the American Chemical Society
Communication
K.-Q.; Shi, Z.-J. J. Am. Chem. Soc. 2008, 130, 3268. (c) Taylor, B. L. H.;
Swift, E. C.; Waetzig, J. D.; Jarvo, E. R. J. Am. Chem. Soc. 2011, 133, 389.
(d) Hu, X.-L. Chem. Sci. 2011, 2, 1867. (e) Maity, P.; Shacklady-McAtee,
D. M.; Yap, G. P. A.; Sirianni, E. R.; Watson, M. P. J. Am. Chem. Soc.
2013, 135, 280. (f) Zultanski, S. L.; Fu, G. C. J. Am. Chem. Soc. 2013, 135,
624. (g) Zhou, Q.; Srinivas, H. D.; Dasgupta, S.; Watson, M. P.; Watson.
J. Am. Chem. Soc. 2013, 135, 3307. (h) Nielsen, D. K.; Huang, C.-Y.;
Doyle, A. G. J. Am. Chem. Soc. 2013, 135, 13605.
(3) (a) Yu, D.-G.; Li, B.-J.; Shi, Z.-J. Acc. Chem. Res. 2010, 43, 1486.
(b) Yu, D.-G.; Shi, Z.-J. Angew. Chem., Int. Ed. 2011, 50, 7097. (c) Yu, D.-
G.; Wang, X.; Zhu, R.-Y.; Luo, S.; Zhang, X.-B.; Wang, B.-Q.; Wang, L.;
Shi, Z.-J. J. Am. Chem. Soc. 2012, 134, 14638.
(4) (a) Yamaguchi, J.; Muto, K.; Itami, K. Eur. J. Org. Chem. 2013, 19.
(b) Rouquet, G.; Chatani, N. Angew. Chem., Int. Ed. 2013, 52, 11726.
(5) (a) Kanyiva, K. S.; Nakao, Y.; Hiyama, T. Angew. Chem., Int. Ed.
2007, 46, 8872. (b) Nakao, Y.; Kanyiva, K. S.; Hiyama, T. J. Am. Chem.
Soc. 2008, 130, 2448. (c) Tobisu, M.; Hyodo, I.; Chatani, N. J. Am.
Chem. Soc. 2009, 131, 12070. (d) Nakao, Y.; Yamada, Y.; Kashihara, N.;
Hiyama, T. J. Am. Chem. Soc. 2010, 132, 13666. (e) Tsai, C.-C.; Shih, W.-
C.; Fang, C.-H.; Li, C.-Y.; Ong, T.-G.; Yap, G. P. A. J. Am. Chem. Soc.
2010, 132, 11887. (f) Hyodo, I.; Tobisu, M.; Chatani, N. Chem.
Commun. 2012, 48, 308. (g) Hyodo, I.; Tobisu, M.; Chatani, N. Chem.
Asian J. 2012, 7, 1357. (h) Liu, S.; Sawicki, J.; Driver, T. G. Org. Lett.
2012, 14, 3744. (i) Nakao, Y.; Idei, H.; Kanyiva, K. S.; Hiyama, T. J. Am.
Chem. Soc. 2009, 131, 15996. (j) Tamura, R.; Yamada, Y.; Nakao, Y.;
Hiyama, T. Angew. Chem., Int. Ed. 2012, 51, 5679.
(e) Beaulieu, L.-P. B.; Sustac Roman, D.; Vallee, F.; Charette, A. B.
Chem. Commun. 2012, 48, 8249. (f) Song, W.-F.; Ackermann, L. Chem.
Commun. 2013, 49, 6638.
(10) (a) Dangel, B. D.; Godula, K.; Youn, S. W.; Sezen, B.; Sames, D. J.
Am. Chem. Soc. 2002, 124, 11856. (b) Zaitsev, V.; Shabashov, D.;
Daugulis, O. J. Am. Chem. Soc. 2005, 127, 13154. (c) Reddy, B. V. S.;
Reddy, L. R.; Corey, E. J. Org. Lett. 2006, 8, 3391. (d) Giri, R.; Maugel,
N.; Foxman, B. M.; Yu, J.-Q. Organometallics 2008, 27, 1667.
(e) Shabashov, D.; Daugulis, O. J. Am. Chem. Soc. 2010, 132, 3965.
(f) He, G.; Chen, G. Angew. Chem., Int. Ed. 2011, 50, 5192. (g) Ano, Y.;
Tobisu, M.; Chatani, N. J. Am. Chem. Soc. 2011, 133, 12984. (h) Ano, Y.;
Tobisu, M.; Chatani, N. Org. Lett. 2012, 14, 354. (i) Tran, L. D.;
Daugulis, O. Angew. Chem., Int. Ed. 2012, 124, 5278. (j) Rodríguez, N.;
́
Romero-Revilla, J. A.; Fernandez-Ibanez, M. A.; Carretero, J. C. Chem.
́ ́
̃
Sci. 2013, 4, 175. (k) Zhang, S.-Y.; He, G.; Nack, W. A.; Zhao, Y.; Li, Q.;
Chen, G. J. Am. Chem. Soc. 2013, 135, 2124. (l) Chen, K.; Hu, F.; Zhang,
S.-Q.; Shi, B.-F. Chem. Sci. 2013, 4, 3906.
(11) Ahihara, Y.; Chatani, N. J. Am. Chem. Soc. 2013, 135, 5308.
(12) Nakao, Y.; Morita, E.; Idei, H.; Hiyama, T. J. Am. Chem. Soc. 2011,
133, 3264.
(13) (a) Koo, K.; Hilhouse, G. L. Organometallics 1995, 14, 4421.
(b) Koo, K.; Hilhouse, G. L. Organometallics 1996, 15, 2669. (c) Lu, Z.-
L.; Abbina, S.; Sabin, J. R.; Nemykin, V. N.; Du, G.-D. Inorg. Chem. 2013,
52, 1454.
(14) (a) Scott, K. R.; Kennedy, P. G.; Kemp, M.; Telang, V. G.;
Matthews, H. W. J. Pharm. Sci. 1983, 72, 183. (b) Scott, K. R.; Moore, J.
A.; Zalucky, T. B.; Nicholson, J. M.; Lee, J. A. M.; Hinko, C. N. J. Med.
Chem. 1985, 28, 413. (c) Tarver, M. L.; Nicholson, J. M.; Scott, K. R. J.
Pharm. Sci. 1985, 74, 785. (d) Hoffman, W. F.; Alberts, A. W.; Anderson,
P. S.; Chen, J. S.; Smith, R. L.; Willard, A. K. J. Med. Chem. 1986, 29, 849.
(e) Huang, Z.; Poulter, C. D.; Wolf, F. R.; Somers, T. C.; White, J. D. J.
Am. Chem. Soc. 1988, 110, 3959. (f) Kenda, B. M.; Matagne, A. C.;
Talaga, P. E.; Pasau, P. M.; Differding, E.; Lallemand, B. I.; Frycia, A. M.;
Moureau, F. G.; Klitgaard, H. V.; Gillard, M. R.; Fuks, B.; Michel, P. J.
Med. Chem. 2004, 47, 530. (g) Werstuck, G. H.; Kim, A. J.; Brenstrum,
T.; Ohnmacht, S. A.; Panna, E.; Capretta, A. Bioorg. Med. Chem. Lett.
2004, 14, 5465. (h) Pryde, D. C.; Maw, G. N.; Planken, S.; Platts, M. Y.;
Sanderson, V.; Corless, M.; Stobie, A.; Barber, C. G.; Russell, R.; Foster,
L.; Barker, L.; Wayman, C.; Van Der Graaf, P.; Stacey, P.; Morren, D.;
Kohl, C.; Beaumont, K.; Coggon, S.; Tute, M. J. Med. Chem. 2006, 49,
4409. (i) Pryde, D. C.; Cook, A. S.; Burring, D. J.; Jones, L. H.; Foll, S.;
Platts, M. Y.; Sanderson, V.; Corless, M.; Stobie, A.; Middleton, D. S.;
Foster, L.; Barker, L.; Van Der Graaf, P.; Stacey, P.; Kohl, C.; Coggon, S.;
Beaumont, K. Bioorg. Med. Chem. 2007, 15, 142. (j) Obniska, J.;
Kaminski, K.; Hondo, L.; Zejc, A. Arch. Pharm. 2007, 340, 404.
(k) Arbour, A.; Roy, S.; Godbout, C.; Spino, C. J. Org. Chem. 2009, 74,
3806.
(15) Shang, R.; Ilies, L.; Matsumoto, A.; Nakamura, E. J. Am. Chem. Soc.
2013, 135, 6030.
(16) (a) Terao, J.; Kambe, N. Acc. Chem. Res. 2008, 41, 1545.
(b) Higgs, A. T.; Zinn, P. J.; Sanford, M. S. Organometallics 2010, 29,
5446.
(17) A stoichiometric amount of Ni(dppbz)I2 or Ni(acac)2 was used to
try to identify the formation of the intermediate A or B. Unfortunately,
neither of the two intermediates was detected by 1H NMR.
(18) For the NiIV or NiIII intermediate C or E, the metal could
coordinate six ligands in maximum, and there are two potential
coordination methods. In the first one, only one phosphine atom in the
phosphine ligand may be involved in this coordination process since the
monodentate phosphine ligands also worked efficiently for the reaction.
In the second one, the coordination between the nickel and pyridine
nitrogen is displaced by the bidentate phosphine ligand.
(6) (a) Nakao, Y.; Kashihara, N.; Kanyiva, K. S.; Hiyama, T. J. Am.
Chem. Soc. 2008, 130, 16170. (b) Kanyiva, K. S.; Kashihara, N.; Nakao,
Y.; Hiyama, T.; Ohashi, M.; Ogoshi, S. Dalton Trans. 2010, 39, 10483.
(c) Doster, M. E.; Hatnean, J. A.; Jeftic, T.; Modi, S.; Johnson, S. A. J. Am.
Chem. Soc. 2010, 132, 11923. (d) Hatnean, J. A.; Beck, R.; Borrelli, J. D.;
́
Johnson, S. A. Organometallics 2010, 29, 6077. (e) Guihaume, J.;
Halbert, S.; Eisenstein, O.; Perutz, R. N. Organometallics 2012, 31, 1300.
(f) Doster, M. E.; Johnson, S. A. Organometallics 2013, 32, 4174.
(7) (a) Clement, N. D.; Cavell, K. J. Angew. Chem., Int. Ed. 2004, 43,
3845. (b) Kanyiva, K. S.; Nakao, Y.; Hiyama, T. Heterocycles 2007, 72,
677. (c) Canivet, J.; Yamaguchi, J.; Ban, I.; Itami, K. Org. Lett. 2009, 11,
1733. (d) Hachiya, H.; Hirano, K.; Satoh, T.; Miura, M. Org. Lett. 2009,
11, 1737. (e) Mukai, T.; Hirano, K.; Satoh, T.; Miura, M. J. Org. Chem.
2009, 74, 6410. (f) Matsuyama, N.; Hirano, K.; Satoh, T.; Miura, M. Org.
Lett. 2009, 11, 4156. (g) Kanyiva, K. S.; Lobermann, F.; Nakao, Y.;
̈
Hiyama, T. Tetrahedron Lett. 2009, 50, 3463. (h) Nakao, Y.; Kashihara,
N.; Kanyiva, K. S.; Hiyama, T. Angew. Chem., Int. Ed. 2010, 49, 4451.
(i) Yao, T.; Hirano, K.; Satoh, T.; Miura, M. Chem.Eur. J. 2010, 16,
12307. (j) Yamamoto, T.; Muto, K.; Komiyama, M.; Canivet, J.;
Yamaguchi, J.; Itami, K. Chem.Eur. J. 2011, 17, 10113. (k) Yao, T.;
Hirano, K.; Satoh, T.; Miura, M. Angew. Chem., Int. Ed. 2012, 51, 775.
(l) Muto, K.; Yamaguchi, J.; Itami, K. J. Am. Chem. Soc. 2012, 134, 169.
(m) Shih, W.-C.; Chen, W.-C.; Lai, Y.-C.; Yu, M-.S.; Ho, J.-J.; Yap, G. P.
A.; Ong, T.-G. Org. Lett. 2012, 14, 2046. (n) Jiang, Y.-Y.; Li, Z.; Shi, J.
Organometallics 2012, 31, 4356. (o) Amaike, K.; Muto, K.; Yamaguchi,
J.; Itami, K. J. Am. Chem. Soc. 2012, 134, 13573. (p) Lee, W.-C.; Wang,
C.-H.; Lin, Y.-H.; Shih, W.-C.; Ong, T.-G. Org. Lett. 2013, 15, 5358.
(q) Meng, L.; Kamada, Y.; Muto, K.; Yamaguchi, J.; Itami, K. Angew.
Chem., Int. Ed. 2013, 52, 10048. (r) Muto, K.; Yamaguchi, J.; Lei, A.-W.;
Itami, K. J. Am. Chem. Soc. 2013, 135, 16384.
(8) (a) Truong, T.; Alvarado, J.; Tran, L. D.; Daugulis, O. Org. Lett.
2010, 12, 1200. (b) Hachiya, H.; Hirano, K.; Satoh, T.; Miura, M.
ChemCatChem 2010, 2, 1403. (c) Hachiya, H.; Hirano, K.; Satoh, T.;
Miura, M. Angew. Chem., Int. Ed. 2010, 49, 2202. (d) Matsuyama, N.;
Kitahara, M.; Hirano, K.; Satoh, T.; Miura, M. Org. Lett. 2010, 12, 2358.
(e) Vechorkin, O.; Proust, V.; Hu, X. Angew. Chem., Int. Ed. 2010, 49,
3061. (f) Qu, G.-R.; Xin, P.-Y.; Niu, H.-Y.; Wang, D.-C.; Ding, R.-F.;
Guo, H.-M. Chem. Commun. 2011, 47, 11140.
(9) (a) Kleiman, J. P.; Dubeck, M. J. Am. Chem. Soc. 1963, 85, 1544.
(b) Shacklady-McAtee, D. M.; Dasgupta, S.; Watson, M. P. Org. Lett.
2011, 13, 3490. (c) Ogata, K.; Atsumi, Y.; Shimada, D.; Fukuzawa, S.
Angew. Chem., Int. Ed. 2011, 50, 5896. (d) Shiota, H.; Ano, Y.; Ahihara,
Y.; Fukumoto, Y.; Chatani, N. J. Am. Chem. Soc. 2011, 133, 14952.
(19) (a) Higgs, A. T.; Zinn, P. J.; Simmons, S. J.; Sanford, M. S.
Organometallics 2009, 28, 6142. (b) Breitenfeld, J.; Ruiz, J.; Wodrich, M.
D.; Hu, X. J. Am. Chem. Soc. 2013, 135, 12004. (c) Biswas, S.; Weix, D. J.
J. Am. Chem. Soc. 2013, 135, 16192.
D
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