Rhodium(iii)-catalyzed coupling of N-sulfonyl 2-aminobenzaldehydes with oxygenated allylic olefins through C-H activation

Article abstract of DOI:10.1039/c4ob00704b

Rh(iii)-catalyzed coupling of N-sulfonyl 2-aminobenzaldehydes with oxygenated allylic olefins via C-H bond activation is described. Diarylketones were obtained through coupling of N-sulfonyl 2-aminobenzaldehydes with 7-oxabenzonorbornadienes. On the other

Full text of DOI:10.1039/c4ob00704b

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Rhodium(III)-catalyzed coupling of N-sulfonyl
2-aminobenzaldehydes with oxygenated allylic
olefins through C–H activation†
Cite this: Org. Biomol. Chem., 2014,
12, 4290
Received 3rd April 2014,
Accepted 29th April 2014
Tingting Yang,‡b,c Tao Zhang,‡b Shangdong Yang,c Shanshan Chen*a and
Xingwei Li*b
DOI: 10.1039/c4ob00704b
www.rsc.org/obc
Rh(III)-catalyzed coupling of N-sulfonyl 2-aminobenzaldehydes are particularly well-known for serving this purpose, where the
with oxygenated allylic olefins via C–H bond activation is C–H activation is proposed to occur via an oxidative addition
described. Diarylketones were obtained through coupling of N-sul- pathway. On the other hand, arenes can also undergo C–H acti-
fonyl 2-aminobenzaldehydes with 7-oxabenzonorbornadienes. On vation followed by oxidative coupling with aldehydes to afford
the other hand, the coupling with allyl carbonate yielded a six- ketones via C–C coupling.5 Despite the significance, reports on
membered sulfonyl lactam via a sequence of allylation–isomeriza- formyl C–H activation of aldehydes by Rh(III) catalysts are
tion–Michael cyclization.
limited,4 probably because the C–H oxidative addition pathway
is unlikely. Assisted by chelating groups, Satoh and Miura,4d
Glorius,4a Radhakrishnan,4b Li4c and we4e have successfully
developed catalytic activation of aldehyde C–H bonds by
subsequent functionalization with unsaturated molecules
(Scheme 1). Despite the progress, the scope of aldehydes still
needs expansion. We reasoned that coupling of aldehydes with
olefins bearing built-in oxidizing groups should be a desirable
redox-economic process for C–C coupling. We now report a
Rh(III)-catalyzed redox-neutral coupling of N-sulfonyl 2-amino-
In the past several decades, the selective functionalization of
C–H bonds catalyzed by transition metals has garnered con-
siderable attention and represents one of the most efficient
strategies to construct complex structures.1 The advantage of
this process stems from its step- and atom-economy and the
abundance of C–H bonds in organic molecules. Thus it rep-
resents an attractive approach in synthetic chemistry,
especially at low catalyst loading and with the low costs associ-
ated with the preparation of starting materials. In recent years,
rhodium(III) complexes have been extensively explored in C–H
activation and subsequent functionalization,2 and Rh(III)Cp*
complexes have stood out as attractive catalysts that render
C–H activation with broad substrate scope, high catalytic
efficiency and good functional group tolerance, and many
elegant systems have been recently reported.2,3
Aldehydes are widely used as simple chemical feedstocks.
The construction of ketones via C–H activation has been recog-
nized as an important strategy to utilize the availability of alde-
hydes. Two categories of reactions have been developed in this
regard. Aldehydes can undergo C–H activation at the formyl
group,4 followed by redox-neutral functionalization with
alkenes or alkynes, leading to hydroacylation. Rh(I) catalysts
aSchool of Natural Sciences, Anhui Agricultural University, Hefei 230036, China.
E-mail: chenshanshan@ahau.edu.cn
bDalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023,
China. E-mail: xwli@dicp.ac.cn
cCollege of Chemistry and Chemical Engineering, Lanzhou University,
Lanzhou 730000, China
†Electronic supplementary information (ESI) available: Experimental details,
characterization data and NMR spectra. See DOI: 10.1039/c4ob00704b
‡T. Y. and T. Z. contributed equally to this work.
Scheme 1 Rhodium-catalyzed acyl C–H activation.
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Table 1 Optimization studiesa
Entry
Catalystb (mol%)
Base (equiv.)
Additive (equiv.)
Solvent
Temp. (°C)
Yieldc (%)
1
2
3
4
5
6
7
8
9
A (2.5)
A (2.5)
A (2.5)
A (2.5)
—
B (5)
C (5)
A (2.5)
A (2.5)
A (2.5)
Ag2CO3 (2)
Ag2CO3 (2)
Ag2CO3 (2)
Ag2CO3 (2)
Ag2CO3 (2)
Ag2CO3 (2)
Ag2CO3 (2)
—
KPF6 (2)
KPF6 (2)
KPF6 (2)
KPF6 (2)
KPF6 (2)
KPF6 (2)
KPF6 (2)
KPF6 (2)
—
DCE
DCE
DCM
Dioxane
DCE
DCE
DCE
DCE
DCE
DCE
110
100
100
100
100
100
100
100
100
100
76
79
69
61
nd
nd
nd
47
35
71
K2CO3 (2)
Ag2CO3 (2)
10
a Reactions were carried out by using a catalyst, oxidant, additive, N-Ts 2-aminobenzaldehyde (0.2 mmol), and 7-oxabenzonorbornadiene
(0.24 mmol) in DCE (2 mL) at 100 or 110 °C for 16 h. b Catalyst A = [RhCp*Cl2]2, B = [RhCp*(MeCN)3](SbF6)2, C = [Ru(p-cymene)Cl2]2. c Isolated
yield after column chromatography.
benzaldehydes with oxygenated allylic olefins such as 7-oxa-
benzonorbornadienes and allyl carbonates.
7-Oxabenzonorbornadienes and analogues have been well
studied as a strained olefin to introduce a (dihydro)naphtha-
lene ring.6 However, integration of C–H activation with (ring-
opening) coupling of strained olefins such as 7-oxabenzonor-
bornadienes has experienced limited precedence.3a,7 With this
in mind, we initiated our studies with the screening of reaction
conditions for the coupling of N-Ts 2-aminobenzaldehyde (1a)
with 7-oxabenzonorbornadiene (2a). We found that a dehydra-
tive coupling reaction occurred when [RhCp*Cl2]2 (2.5 mol%)
was used as a catalyst and Ag2CO3 was used as a base in the
presence of KPF6 in DCE (110 °C, Table 1, entry 1). NMR ana-
lyses of the major product isolated pointed to a diaryl ketone
3aa as a result of 2-naphthylation of the aldehyde C–H bond.3a
When Ag2CO3 was omitted or switched to K2CO3, the coupling
occurred with lower efficiency (entries 8 and 9), indicating that
Ag2CO3 is playing a unique role as a base although it is a
typical oxidant in coupling reactions. In addition, poor results
were obtained when the solvent was switched to DCM or 1,4-
dioxane (entries 3 and 4). To our delight, a slightly higher
yield was isolated when the temperature was lowered to 100 °C
(entry 2). In contrast, lower yield was isolated when the KPF6
additive was omitted (entry 10) and no reaction occurred when
Scheme 2 Substrate scope of the dehydrative naphthylation. Reaction
conditions: N-sulfonyl 2-aminobenzaldehyde (0.2 mmol), 7-oxabenzo-
norbornadiene (0.24 mmol), [RhCp*Cl2]2 (0.005 mmol), Ag2CO3
(0.4 mmol), KPF6 (0.4 mmol) in DCE (2 mL) at 100 °C for 16 h. Isolated
the rhodium catalyst was omitted or when other catalysts were
used (entries 5–7).
With these optimized conditions in hand, we set out to
explore the scope and limitations of this coupling system. A
yield after column chromatography.
broad scope of N-Ts 2-aminobenzaldehyde has also been
defined (Scheme 2). Thus electron-withdrawing, -donating and
was extended to a 2-thiophenaldehyde, the coupling reaction
still occurred to afford 3oa in 81% yield. What is more, a series
of 7-oxabenzonorbornadienes underwent smooth coupling
with 1a and the 2-naphthylation products were isolated in
71–81% yield. In the case of fluorine-substituted 7-oxabenzo-
norbornadiene, a regioisomeric mixture of naphthylation pro-
halogen groups at different positions of the benzene ring are
well tolerated, including a nitro substituent which is usually
problematic in C–H activation reactions.8 Variation of the sul-
fonyl group is also tolerated, and moderate to high yields were
isolated when methyl and aryl-substituted sulfonyls were
applied (3ga–3na). Importantly, when the benzaldehyde ring
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formed. Using CsOAc as a base additive in the presence of the
[RhCp*Cl2]2 catalyst, a reaction occurred and, interestingly, a
sulfonyl lactam 6a was isolated in 41% yield (Table 2, entry 1).
Product 6a was proposed to be generated via allylation fol-
lowed by isomerization to a conjugated ketone. Intramolecular
aza-Michael addition of the NHT directing group furnished
the final product.11 Extensive screening gave allyl carbonate as
a more efficient substrate and an optimal yield of 85% was
isolated when RhCp*(OAc)2 was employed as a catalyst in the
presence of CsOPiv (1.5 equiv.).
Scheme 3 Mechanistic studies.
Under these optimized conditions, the scope of this reac-
tion was next explored (Scheme 4). A series of N-sulfonyl-2-
aminobenzaldehyde coupled smoothly with ally carbonate,
and the cyclic sulfonamides (6a–6m) were isolated in good to
high yield (57–85%). In line with the coupling of 7-oxabenzo-
norbornadiene, the scope of the N-sulfonyl-2-aminobenzalde-
ducts was obtained in a 1 : 0.9 ratio and in 81% total yield
(3ac). The sulfonyl group in the product may serve as a useful
handle for further chemical manipulations.
Several experiments have been carried out to explore the
reaction mechanism. To demonstrate the relevancy of C–H
activation, a rhodacyclic acyl complex 4 was prepared4e and hyde is broad in terms of the substitute in the benzene ring
was designated as a catalyst (Scheme 3). Indeed, complex 4
(5 mol%) proved active for the coupling of 1a and 2a to give
and in the sulfonyl group. Extension of the benzaldehyde sub-
strate to a 2-thiophenaldehyde also gave the desired product
3aa in 74% yield. Therefore C–H activation is involved. To 6n in moderate yield (60%). Extension of the sulfonamide
further probe this C–H activation process, intermolecular
kinetic isotope effect (KIE) has been measured in the competi-
directing group to a hydroxyl group as in the coupling of salicyl-
aldehyde 7, however, only affords a conjugated enone 8 in
tive coupling of an equimolar mixture of 1a and 1a-d with moderate yield (eqn (1)), and no cyclization was involved,
7-oxabenzonorbornadiene.9 1H NMR analysis of the level of
indicative of the differences in steric and electronic effects of
deuteration of the recovered (isotopically mixed) aldehydes
gave KIE = 1.9 at 24% conversion (HPLC). This KIE value indi- substituent at the allylic and olefinic positions of the allyl car-
the protic directing groups. The reaction is sensitive to the
cates that cleavage of the C–H bond may be involved in the
bonate because poor conversion was observed for but-3-en-2-yl
methyl carbonate and cinnamyl methyl carbonate. Desulfonyl-
rate-limiting step.
With the development of these dehydrative naphthylation ation of the product to give a protic amine has been reported12
reactions, we next extended the strained olefins to allyl esters.
Recently, allyl esters have been applied to the allylation of
arenes by rhodium catalysis via a C–H activation pathway.10
Our initial finding revealed that the reaction of 1a and allyl
acetate under the standard conditions in Scheme 2 failed to
and this structural motif has been widely encountered in
natural products and pharmaceuticals.13
A plausible mechanism to account for the formation of
lactam 6 is given in Scheme 5. Sulfonamide coordination and
cyclometalation affords a rhodacycle. Subsequent olefin inser-
give any conversion. Thus further screening has been per- tion into the Rh–C bond generates a Rh(III) alkyl intermediate,
Table 2 Optimization studies of the coupling with allyl estersa
Entry
R
Catalystb (mol%)
Solvent
Additive (equiv.)
Temp. (°C)
Yieldc (%)
1
2
3
4
5
6
7
8
Ac
Ac
A (2.5)
A (2.5)
B (2.5)
B (2.5)
B (2.5)
B (2.5)
B (2.5)
B (2.5)
B (2.5)
B (2.5)
B (2.5)
DCE
DCE
DCE
DCE
DCE
DCE
DCM
THF
Dioxane
Acetone
t-AmOH
CsOAc (1.0)
PivOCs (1.0)
PivOCs (1.0)
PivOCs (1.0)
PivOCs (1.0)
PivOCs (1.5)
PivOCs (1.5)
PivOCs (1.5)
PivOCs (1.5)
PivOCs (1.5)
PivOCs (1.5)
100
100
100
80
120
100
100
100
100
100
100
41
61
75
72
75
85
10
71
72
20
70
COOMe
COOMe
COOMe
COOMe
COOMe
COOMe
COOMe
COOMe
COOMe
9
10
11
Conditions: a Reactions were carried out by using a catalyst, additive, N-Ts 2-aminobenzaldehyde (0.2 mmol), and allyl acetate or allyl methyl
carbonate (0.6 mmol) in DCE (2 mL) at 100 °C for 16 h. b Catalyst A = [RhCp*Cl2]2, B = RhCp*(OAc)2. c Isolated yield after column
chromatography.
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Conclusions
In conclusion, we have demonstrated a rhodium(III)-catalyzed
redox-neutral coupling of N-sulfonyl 2-aminobenzaldehydes
with oxygenated allylic olefins such as 7-oxabenzonorborna-
dienes and allyl carbonate. The coupling of 7-oxabenzonorbor-
nadienes resulted in 2-naphthylation of the aldehyde group,
while the coupling of allyl carbonate yielded a six-membered
sulfonamide via an allylation–isomerization–Michael cycliza-
tion sequence. These synthetic methods serve to broaden the
scope of rhodium(III)-catalyzed C–H activation/functionali-
zation reactions, particularly under redox-neutral conditions,
and may find applications in synthetic chemistry. Further
experimental and theoretical investigations are underway in
our laboratory.
Notes and references
1 For reviews, see: (a) N. Kuhl, M. N. Hopkinson, J. Wencel-
Delord and F. Glorius, Angew. Chem., 2012, 124, 10382,
(Angew. Chem. Int. Ed., 2012, 51, 10236); (b) P. B. Arockiam,
C. Brunean and P. H. Dixneuf, Chem. Rev., 2012, 112, 5879;
(c) K. M. Engle, T.-S. Mei, M. Wasa and J.-Q. Yu, Acc. Chem.
Res., 2012, 45, 788; (d) P. B. Arockiam, C. Bruneau and
P. H. Dixneuf, Chem. Rev., 2012, 112, 5879; (e) C. S. Yeung
and V. M. Dong, Chem. Rev., 2011, 111, 1215;
(f) L. Ackermann, Chem. Rev., 2011, 111, 1315; (g) X. F. Wu,
P. Anbarasan, H. Neumann and M. Beller, Angew. Chem.,
2010, 122, 9231, (Angew. Chem. Int. Ed., 2010, 49, 9047);
(h) S. H. Cho, J. Y. Kim, J. Kwak and S. Chang, Chem. Soc.
Rev., 2011, 40, 5068; (i) W. R. Gutekunst and P. S. Baran,
Chem. Soc. Rev., 2011, 40, 1976; ( j) J. Wencel-Delord,
T. Droge, F. Liu and F. Glorius, Chem. Soc. Rev., 2011, 40,
4740; (k) T. W. Lyons and M. S. Sanford, Chem. Rev., 2010,
110, 1147; (l) C.-L. Sun, B.-J. Li and Z.-J. Shi, Chem. Rev.,
2010, 111, 1293; (m) D. A. Colby, R. G. Bergman and
J. A. Ellman, Chem. Rev., 2010, 110, 624; (n) R. Giri,
B.-F. Shi, K. M. Engle, N. Maugel and J.-Q. Yu, Chem. Soc.
Rev., 2009, 38, 3242.
Scheme 4 Substrate scope of N-sulfonyl-2-aminobenzaldehydes.
Reaction conditions: N-Ts 2-aminobenzaldehyde (0.2 mmol), allyl
methyl carbonate (0.6 mmol), RhCp*(OAc)2 (0.005 mmol), PivOCs
(0.3 mmol) in DCE (2 mL) at 100 °C for 16 h. Isolated yield after column
chromatography.
2 Reviews on Rh(III)-catalyzed C–H activation: (a) G. Song,
F. Wang and X. Li, Chem. Soc. Rev., 2012, 41, 3651;
(b) F. W. Patureau, J. Wencel-Delord and F. Glorius, Aldrichi-
mica Acta, 2012, 45, 31; (c) D. A. Colby, A. S. Tsai,
R. G. Bergman and J. A. Ellman, Acc. Chem. Res., 2011, 45,
814; (d) T. Satoh and M. Miura, Chem. – Eur. J., 2010, 16,
11212; (e) N. Kuhl, N. Schröder and F. Glorius, Adv. Synth.
Catal., 2014, 356, 1443. For selected individual reports, see:
(f) C. Wang, H. Chen, Z. Wang, J. Chen and Y. Huang,
Angew. Chem., Int. Ed., 2012, 51, 7242; (g) K. Muralirajan
Scheme 5 Plausible mechanism.
which undergoes β-elimination of a methyl carbonate group to
give the allylation intermediate. Isomerization of the double
bond and intramolecular aza-Michael reaction furnish the
final product.
and C.-H. Cheng, Chem.
– Eur. J., 2013, 19, 6198;
(h) C. Wang, H. Sun, Y. Fang and Y. Huang, Angew. Chem.,
Int. Ed., 2013, 52, 5795; (i) Y. Lian, R. G. Bergman,
L. D. Lavis and J. A. Ellman, J. Am. Chem. Soc., 2013,
135, 7122; ( j) T. Zhang, L. Wu and X. Li, Org. Lett., 2013,
15, 6294; (k) A. Seoane, N. Casanova, N. Quiñones,
ð1Þ
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J. L. Mascareñas and M. Gulías, J. Am. Chem. Soc., 2014,
136, 834; (l) X. Huang, J. Huang, C. Du, X. Zhang, F. Song
and J. You, Angew. Chem., Int. Ed., 2013, 52, 12970;
(m) X.-S. Zhang, Q.-L. Zhu, Y.-F. Zhang, Y.-B. Li and
Z.-J. Shi, Chem. – Eur. J., 2013, 19, 11898; (n) R. Zeng,
S. Wu, C. Fu and S. Ma, J. Am. Chem. Soc., 2013, 135, 18284;
(o) S. Rakshit, C. Grohmann, T. Besset and F. Glorius,
J. Am. Chem. Soc., 2011, 133, 2350.
(d) L. Li, D. Rayabarapu, M. Nandi and C. Cheng, Org. Lett.,
2003, 5, 1621; (e) M. Lautens and C. Dockendorff, Org.
Lett., 2003, 5, 3695; (f) M. Lautens and S. Hiebert, J. Am.
Chem. Soc., 2004, 126, 1437; (g) T. Ogura, K. Yoshida,
A. Yanagisawa and T. Imamoto, Org. Lett., 2009, 11, 2245.
Cu catalysis: (h) M. Lautens, J.-L. Renaud and S. Hiebert,
J. Am. Chem. Soc., 2000, 122, 1804; (i) R. Arrayas, S. Cabrera
and J. Carretero, Org. Lett., 2003, 5, 1333; ( j) R. Millet,
L. Gremaud, T. Bernardez, L. Palais and A. Alexakis, Syn-
thesis, 2009, 2101. Rh catalysis: (k) M. Lautens, K. Fagnou
and M. Taylor, Org. Lett., 2000, 2, 1677; (l) M. Lautens,
C. Dock-endorff, K. Fagnou and A. Malicki, Org. Lett., 2002,
4, 1311; (m) M. Lautens, K. Fagnou and V. Zunic, Org. Lett.,
2002, 4, 3465; (n) M. Lautens, K. Fagnou and D. Yang,
J. Am. Chem. Soc., 2003, 125, 14884; (o) R. Webster,
A. Boyer, M. J. Fleming and M. Lautens, Org. Lett., 2010, 12,
5418; (p) T. D. Nguyen, R. Webster and M. Lautens, Org.
Lett., 2011, 13, 1370.
7 (a) X. Peng, Y. Zhu, T. A. Ramirez, B. Zhao and Y. Shi, Org.
Lett., 2011, 13, 5244; (b) C. Aïssa and A. Fürstner, J. Am.
Chem. Soc., 2007, 129, 14836. For insertion of heteroarenes
into related bicycloalkenes, see: (c) C. S. Sevov and
J. F. Hartwig, J. Am. Chem. Soc., 2013, 135, 2116. For the
coupling of Rh–C bonds with strained CvC bonds, see:
(d) K. Sakabe, H. Tsurugi, K. Hirano, T. Satoh and
M. Miura, Chem. – Eur. J., 2010, 16, 445.
3 (a) Z. Qi and X. Li, Angew. Chem., Int. Ed., 2013, 52, 8995;
(b) K. Wu, Z. Fan, Y. Xue, Q. Yao and A. Zhang, Org. Lett.,
2013, 16, 42.
4 (a) Z. Shi, N. Schröder and F. Glorius, Angew. Chem., Int.
Ed., 2012, 51, 8092; (b) E. Jijy, P. Prakash, M. Shimi,
P. M. Pihko, N. Joseph and K. V. Radhakrishnan, Chem.
Commun., 2013, 49, 7349. For formyl C–H activation with
subsequent C–N coupling, see: (c) B. Zhou, D. Yang, J. Shi,
H. Feng and Y. Li, Chem. – Eur. J., 2013, 19, 10511;
(d) M. Shimizu, H. Tsurugi, T. Satoh and M. Miura, Chem. –
Asian. J., 2008, 3, 881; (e) T. Zhang, Z. Qi, X. Zhang, L. Wu
and X. Li, Chem. – Eur. J., 2014, 20, 3283.
5 For selected examples on Rh(I)-catalyzed hydroacylation
reactions, see: (a) H.-J. Zhang and C. Bolm, Org. Lett., 2011,
13, 3900; (b) M. von Delius, C. M. Le and V. M. Dong, J. Am.
Chem. Soc., 2012, 134, 15022; (c) S. K. Murphy,
M. M. Coulter and V. M. Dong, Chem. Sci., 2012, 3, 355;
(d) T. J. Hoffman and E. M. Carreira, Angew. Chem., Int. Ed.,
2011, 50, 10670; (e) H. A. Khan, K. G. M. Kou and
V. M. Dong, Chem. Sci., 2011, 2, 407; (f) M. M. Coulter,
K. G. M. Kou, B. Galligan and V. M. Dong, J. Am. Chem.
Soc., 2010, 132, 16330; (g) D. H. T. Phan, K. G. M. Kou and
V. M. Dong, J. Am. Chem. Soc., 2010, 132, 16354;
(h) D. Crépin, J. Dawick and C. Aïssa, Angew. Chem., 2010,
122, 630, (Angew. Chem. Int. Ed., 2010, 49, 620);
8 (a) X. Ren, P. Wen, X. Shi, Y. Wang, J. Li, S. Yang, H. Yan
and G. Huang, Org. Lett., 2013, 15, 5194; (b) F. Wang,
G. Song and X. Li, Org. Lett., 2010, 12, 5430.
1
9 On the basis of H NMR analysis of the aldehyde starting
material recovered from the coupling of 1a-d with 2a, no
H/D scrambling occurred at the formyl group at 65%
conversion.
(i) J. D. Osborne, H. E. Randell-Sly, G. S. Currie, 10 (a) H. Wang, N. Schröder and F. Glorius, Angew. Chem., Int.
A. R. Cowley and M. C. Willis, J. Am. Chem. Soc., 2008, 130,
17232; ( j) P. Álvarez-Bercedo, A. Flores-Gaspar, A. Correa
and R. Martin, J. Am. Chem. Soc., 2010, 132, 466;
(k) Z. Shen, H. A. Khan and V. M. Dong, J. Am. Chem. Soc.,
Ed., 2013, 52, 5386; (b) H. Wang, B. Beiring, D. G. Yu,
K. D. Collins and F. Glorius, Angew. Chem., Int. Ed., 2013,
52, 12430; (c) C. Feng, D. Feng and T.-P. Loh, Org. Lett.,
2013, 15, 3670.
2008, 130, 2916; (l) M. Tanaka, M. Imai, Y. Yamamoto, 11 J. Song, L. M. Jones, G. E. Chavarria, A. K. Charlton-Sevcik,
K. Tanaka, M. Shimowatari, S. Nagumo, N. Kawahara and
H. Suemune, Org. Lett., 2003, 5, 1365; (m) A. B. Chaplin,
J. F. Hooper, A. S. Weller and M. C. Willis, J. Am. Chem.
Soc., 2012, 134, 4885; (n) K. Kokubo, K. Matsumasa,
A. Jantz, A. Johansen, L. Bayeh, V. Soeung, L. K. Snyder,
S. D. Lade Jr., D. J. Chaplin, M. L. Trawick and
K. G. Pinney, Bioorg. Med. Chem. Lett., 2013, 23,
2801.
Y. Nishinaka, M. Miura and M. Nomura, Bull. Chem. Soc. 12 (a) X. Liu and Y. Lu, Org. Lett., 2010, 12, 5592;
Jpn., 1999, 72, 303; (o) K. Kokubo, K. Matsumasa, M. Miura
and M. Nomura, J. Org. Chem., 1997, 62, 4564. For hydro-
acylation catalyzed by other metals, see: (p) Y. Nakao,
H. Idei, K. S. Kanyiva and T. Hiyama, J. Am. Chem. Soc.,
2009, 131, 5070; (q) N. Armanimo and E. M. Carreira, J. Am.
Chem. Soc., 2013, 135, 6814.
(b) E. H. Gold and E. Babad, J. Org. Chem., 1972, 37, 2208;
(c) B. V. S. Reddy, D. N. Chaya, J. S. Yadav and R. Grée, Syn-
thesis, 2012, 44, 297; (d) H.-S. Chong, K. Garmestani,
L. H. Bryant and M. W. Brechbiel, J. Org. Chem., 2001, 66,
7745; (e) H. Senboku, K. Nakahara, T. Fukuhara and
S. Hara, Tetrahedron Lett., 2010, 51, 435.
6 For a review, see: (a) M. Lautens, K. Fagnou and S. Hiebert, 13 (a) Y. Xia, Z.-Y. Yang, P. Xia, K. F. Bastow, Y. Tachibana,
Acc. Chem. Res., 2003, 36, 48. For selective examples, see: Ni
catalysis: (b) M. Lautens, P. Chiu, S. Ma and T. Rovis, J. Am.
Chem. Soc., 1995, 117, 532; (c) M. Lautens, S. Ma and
P. Chiu, J. Am. Chem. Soc., 1997, 119, 6478. Pd catalysis:
S.-C. Kuo, E. Hamel, T. Hackl and K.-H. Lee, J. Med. Chem.,
1998, 41, 1155; (b) S.-X. Zhang, J. Feng, S.-C. Kuo, A. Brossi,
E. Hamel, A. Tropsha and K.-H. Lee, J. Med. Chem., 2000,
43, 167.
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