Rhodium(III)-Catalyzed [3+2]/[5+2] Annulation of 4-Aryl 1,2,3-Triazoles with Internal Alkynes through Dual C(sp2)-H Functionalization

Article abstract of DOI:10.1002/anie.201501260

A rhodium(III)-catalyzed [3+2]/[5+2] annulation of 4-aryl 1-tosyl-1,2,3-triazoles with internal alkynes is presented. This transformation provides straightforward access to indeno[1,7-cd]azepine architectures through a sequence involving the formation of

Full text of DOI:10.1002/anie.201501260

Angewandte
Chemie
International Edition: DOI: 10.1002/anie.201501260
German Edition: DOI: 10.1002/ange.201501260
Synthetic Methods
Rhodium(III)-Catalyzed [3+2]/[5+2] Annulation of 4-Aryl 1,2,3-
2
À
Triazoles with Internal Alkynes through Dual C(sp ) H
Functionalization**
Yuan Yang, Ming-Bo Zhou, Xuan-Hui Ouyang, Rui Pi, Ren-Jie Song, and Jin-Heng Li*
Abstract: A rhodium(III)-catalyzed [3+2]/[5+2] annulation
of 4-aryl 1-tosyl-1,2,3-triazoles with internal alkynes is pre-
sented. This transformation provides straightforward access to
pines. Generally, these methods require several steps for the
construction of the core 1H-benzo[d]azepine structure.[2,3]
Thus, the development of new efficient methods, and
especially straightforward strategies, for building these core
structures is desirable.
Recently, the use of 1-sulfonyl-1,2,3-triazoles as ideal
precursors of RhII azavinyl carbenes has attracted more and
more attention, as their conversion into valuable nitrogen-
containing compounds, in particular N-heterocyclic com-
pounds, is uniquely practical.[4–6] Attractive transformations
include the rhodium(II)-catalyzed reaction of 1-sulfonyl-
1,2,3-triazoles with various aromatic rings (Scheme 2a).[5]
indeno[1,7-cd]azepine architectures through
a sequence
involving the formation of a rhodium(III) azavinyl carbene,
2
À
dual C(sp ) H functionalization, and [3+2]/[5+2] annulation.
A
zepines and their derivatives,[1,2] including 1H-benzo[d]-
azepines (Scheme 1),[2] are structural motifs in numerous
natural products and pharmaceuticals with diverse biological
and medicinal properties, such as antitumor, antibiotic, and
anti-inflammatory activity. For example, hainanensine[2a–e]
and cephalotaxine[2g–i] were isolated from the antileukemia
plants, Cephalotaxus hainanensis and C. fortunei, and found to
have marginal antitumor activity. Lorcaserin (APD-356)[2p]
has high affinity for the serotonin 5-HT2C receptor and gained
FDA approval in 2012 for the treatment of obesity. Therefore,
considerable effort has been devoted to the development of
efficient methods for the synthesis of such 1H-benzo[d]aze-
Scheme 1. Important benzo[d]azepine compounds.
Scheme 2. Annulation with 1-sulfonyl 1,2,3-triazoles. Cp*=penta-
methylcyclopentadienyl, Ts=p-toluenesulfonyl.
[*] Y. Yang, M.-B. Zhou, X.-H. Ouyang, R. Pi, Dr. R.-J. Song,
Prof. Dr. J.-H. Li
These aromatic rings have served as dipolarophiles for
State Key Laboratory of Chemo/Biosensing and Chemometrics
College of Chemistry and Chemical Engineering, Hunan University
Changsha 410082 (China)
[3+2] cycloaddition with the RhII azavinyl carbenes[5a–c] or
2
À
provided aryl C(sp ) H bonds for intramolecular annulation
with the carbenes.[5d–g] However, such successful approaches
are quite rare,[4] and most are restricted to aromatic rings that
contain or are directly linked to an electron-rich heteroatom
(a nitrogen or oxygen atom) for the formation the key
zwitterion intermediates. In light of these challenges and
E-mail: jhli@hnu.edu.cn
Prof. Dr. J.-H. Li
State Key Laboratory of Applied Organic Chemistry
Lanzhou University
Lanzhou 730000 (China)
À
recent progress in rhodium(III)-catalyzed C H oxidative
[**] We thank the Natural Science Foundation of China (Nos. 21472039
and 21172060) and Hunan Provincial Natural Science Foundation
of China (No. 13JJ2018) for financial support.
annulation reactions with p components,[7] we envisioned that
by adding a viable 2p component, both the carbene and the
2
À
aryl C(sp ) H bond could be trapped in novel annulation
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201501260.
reactions to build new cyclic compounds (Scheme 2a).
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Herein, we report a new rhodium(III)-catalyzed [3+2]/[5+2]
annulation of 4-aryl 1-tosyl-1,2,3-triazoles with internal
3aa decreased when the amount of H2O was increased to
6 equivalents (63%; Table 1, entry 11).
alkynes (Scheme 2b). This method enables the functionaliza-
We next explored the scope of this rhodium-catalyzed
[3+2]/[5+2] annulation reaction with regard to 4-aryl 1-tosyl-
1,2,3-triazoles 1 and internal alkynes 2 [Schemes 2 and 3 and
Eq. (1)]. The optimal conditions were compatible with
a variety of substituents, namely, Me, MeO, CO2Me, F, Cl,
and Br, on the aromatic ring of the 4-aryl moiety (Scheme 3).
2
À
tion of two aryl C(sp ) H bonds in 4-aryl 1,2,3-triazoles with
two alkyne molecules, and provides a new straightforward
route to the indeno[1,7-cd]azepine architecture.[3] To the best
of our knowledge, no metal-catalyzed [3+2]/[5+2] annulation
2
À
of 4-aryl 1,2,3-triazoles through dual C(sp ) H functionaliza-
tion has been reported previously.
An initial investigation was carried out with 4-phenyl-1-
tosyl-1H-1,2,3-triazole (1a) and 1,2-diphenylethyne (2a) as
reaction partners (Table 1). Extensive screening of various
Table 1: Screening of reaction conditions.[a]
Entry
Variation from the standard conditions
Yield [%][b]
1
2
none
at 608C
70
23
3
at 1008C
64
4
5
6
7
without [{Cp*RhCl2}2]
[{Cp*RhCl2}2] (2 mol%)
[{Cp*RhCl2}2] (10 mol%)
without AgSbF6
0
40
71
0
8
9
10
11
AgOAc, Ag2CO3, or AgOTf instead of AgSbF6
without Cu(OAc)2·H2O
tAmOH or toluene instead of CH2ClCH2Cl
H2O (6 equiv)
trace
0
<10
63
[a] Reaction conditions: 1a (0.15 mmol), 2a (2.5 equiv), H2O (3 equiv),
.
[{Cp*RhCl2}2] (5 mol%), AgSbF6 (20 mol%), Cu(OAc)2 H2O (2 equiv),
CH2ClCH2Cl (anhydrous, 1.5 mL), 858C, argon atmosphere, 15 h. The
d.r. value of the product was >20:1, as determined by 1H NMR
spectroscopic analysis of the crude product. [b] Yield of the isolated
product.
Scheme 3. Annulation of 4-aryl 1,2,3-triazoles 1 with 1,2-diaryl alkynes
2. [a] Reaction conditions: 1 (0.15 mmol), 2 (2.5 equiv), [{Cp*RhCl2}2]
(5 mol%), AgSbF6 (20 mol%), Cu(OAc)2·H2O (2 equiv), H2O (3 equiv),
CH2ClCH2Cl (anhydrous, 1.5 mL), 858C, argon atmosphere, 15 h. The
products were formed with d.r.>20:1, as determined by 1H NMR
spectroscopic analysis of the crude product. Bn=benzyl.
reaction parameters revealed that the optimal conditions for
the [3+2]/[5+2] annulation reaction were the use of H2O
(3 equiv), [{Cp*RhCl2}2] (5 mol%), AgSbF6 (20 mol%), and
Cu(OAc)2 (2 equiv) in the medium CH2ClCH2Cl at 858C
under an argon atmosphere. Under these conditions the
desired indeno[1,7-cd]azepin-1-ol 3aa was obtained in 70%
yield (Table 1, entry 1).[8] A higher or lower reaction temper-
ature had a negative effect on the reaction (Table 1, entries 1–
3). Notably, control experiments confirmed that the RhIII
catalyst, AgSbF6, and the Cu oxidant played an important
role in the reaction: When any one of these species was
omitted, no detectable product 3aa was formed (Table 1,
entries 4, 7, and 9). Furthermore, other Ag salts, including
AgOAc, Ag2CO3, and AgOTf, did not promote the reaction
(Table 1, entry 8). These results support the hypothesis that
the only role of AgSbF6 is to activate the RhIII species.[7] Two
other solvents, 2-methylbutan-2-ol (tert-amyl alcohol,
tAmOH) and toluene, were found to be less effective than
CH2ClCH2Cl (Table 1, entry 1 versus entry 10). The yield of
For example, triazole 1b with a p-methyl-substituted aryl ring
was smoothly converted into the desired indeno[1,7-cd]aze-
pin-1-ol 3ba in the presence of 1,2-diphenylethyne (2a), H2O,
[{Cp*RhCl2}2], AgSbF6, and Cu(OAc)2. However, the o-
methyl-substituted substrate 1d formed only the [3+2]
annulation product 3da in 86% yield. Triazole 1e with an
electron-withdrawing CO2Me substituent was also suitable
for the construction of 3ea, albeit in lower yield. Interestingly,
halogen groups, F, Cl, and Br, were well-tolerated under the
optimal conditions (products 3 fa–ha), thus providing oppor-
tunities for additional modification of the product. However,
triazole 1i, with a benzyl group instead of the Ts group, was
inert (no formation of 3ia). Four other symmetrical 1,2-diaryl-
substituted alkynes 2b–e were subsequently subjected to
2
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reaction with triazole 1a and gave the corresponding products
3ab–ae in moderate yields.
Interestingly, cyclopropyl groups could be readily introduced
into the azepine structure (product 4am) by using a cyclo-
propyl-substituted alkyne.
The [3+2]/[5+2] annulation was examined with nucleo-
philes other than H2O [Eq. (1)]. The alcohols EtOH and
Gratifyingly, this [3+2]/[5+2] annulation reaction was
applicable to internal alkyl alkynes; however, the chemo-
selectivity was shifted toward the formation of 1-
methyleneindeno[1,7-cd]azepines 4 rather than indeno[1,7-
cd]azepin-1-ols 3 (Scheme 4). When phenylpropyne (2 f) was
PhCH2OH were found to successfully participate in the
[3+2]/[5+2] annulation reaction, but they were less reactive
than H2O, and the products were formed in moderate yield.
Gratifyingly, oxidation of the indeno[1,7-cd]azepin-1-ol 3aa
by pyridinium chlorochromate (PCC) readily occurred to
afford a new azepine, (benzo[d]azepine-5,6-diyl)bis(phenyl-
methanone) (8aa),[8] in quantitative yield [Eq. (2)].[9]
We propose the mechanism outlined in Scheme 5 for the
[3+2]/[5+2] annulation reaction on the basis of the present
results (see Scheme S1 in the Supporting Information) and
previous reports.[4–6] Initially, the reaction of triazole 1a with
the active Cp*RhX2 species (generated in situ from
[{Cp*RhCl2}2] and AgSbF6)[7] readily produces the rhodium-
(III) carbenoid intermediate A.[10] The addition of intermedi-
ate A to an alkyne 2 affords intermediate B, which undergoes
electrophilic cyclization involving one of the phenyl groups to
give intermediate C.[4–6] A second annulation of intermediate
C with alkyne 2 leads to the formation of the Cp*(H)Rh-
coordinated intermediate D.[4] Intermediate D undergoes
trans addition to give intermediate E as a result of the
coordination of Rh with the nitrogen atom;[8] at this stage
a hydrogen atom from H2O is introduced (see Scheme S1 and
Figure S1 in the Supporting Information). When 1,2-diphe-
Scheme 4. Annulation of 4-aryl 1,2,3-triazoles 1 with alkyl alkynes 2.
[a] For reaction conditions, see Table 1. [b] The Z/E isomer ratio is
given in parenthesis. [c] A side product 5am was obtained in 14%
yield (see Scheme S1 in the Supporting Information).
À
nylacetylene (2a) is used, cleavage of the C Rh bond with the
aid of Cu(OAc)2 through hydration with H2O by backside
used as the alkyne substrate with various 4-aryl 1-tosyl-1,2,3-
triazoles 1a–g, 1-methyleneindeno[1,7-cd]azepines 4af–gf
were furnished selectively in moderate to good yields.[8] In
contrast, the reaction of 4-(m-tolyl)-1-tosyl-1H-1,2,3-triazole
(1h) with phenylpropyne (2 f) delivered a mixture of
regioisomers 4hf. We were pleased to find that an array of
propynes 2g–k with various aryl substituents (4-MeC6H4, 4-
MeOC6H4, 4-ClC6H4, 4-BrC6H4, and 4-CO2MeC6H4) at the
terminal alkyne position were suitable substrates for this
reaction. Thus, products 4ag–ak were obtained in 52–65%
yield. In the case of 1-(4-methoxyphenyl)hept-1-yne (2l),
a mixture of Z and E isomers 4al was obtained in 58% yield.
À
attack of the C Rh bond take place to furnish product 3aa
and regenerate the active Cp*RhX2 species. On the other
hand, when phenylpropyne (2 f) is used, the C Rh bond is
cleaved by Cu(OAc)2, and selective b-H elimination then
provides product 4af. It is also possible that the second
annulation proceeds by a C H activation process (from
À
À
intermediate C to intermediate F).
In summary, we have developed a novel rhodium-
catalyzed [3+2]/[5+2] annulation of 4-aryl 1,2,3-triazoles
with internal alkynes for the selective synthesis of indeno-
[1,7-cd]azepin-1-ols and 1-methyleneindeno[1,7-cd]azepines.
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Pharmacol. 1978, 50, 419; Lorcaserin: p) J. W.
Fleming, K. S. McClendon, D. M. Riche, Ann.
Pharmacother. 2013, 47, 1007.
[3] For pioneering studies on the synthesis of aze-
pines by the [5+2] cycloaddition strategy, see:
a) E. L. Stogryn, S. J. Brois, J. Am. Chem. Soc.
1967, 89, 605; b) A. Hassner, R. DꢀCosta, A. T.
McPhail, W. Butler, Tetrahedron Lett. 1981, 22,
3691; c) P. A. Wender, T. M. Pedersen, M. J. C.
Scanio, J. Am. Chem. Soc. 2002, 124, 15154; d) M.-
B. Zhou, R.-J. Song, C.-Y. Wang, J.-H. Li, Angew.
Chem. Int. Ed. 2013, 52, 10805; Angew. Chem.
2013, 125, 11005; e) D. J. Lee, H. S. Han, J. Shin,
E. J. Yoo, J. Am. Chem. Soc. 2014, 136, 11606.
[4] a) B. Chattopadhyay, V. Gevorgyan, Angew.
Chem. Int. Ed. 2012, 51, 862; Angew. Chem.
2012, 124, 886; b) A. V. Gulevich, V. Gevorgyan,
Angew. Chem. Int. Ed. 2013, 52, 1371; Angew.
Chem. 2013, 125, 1411; c) H. M. L. Davies, J. S.
Scheme 5. Possible reaction mechanism.
Alford, Chem. Soc. Rev. 2014, 43, 5151.
[5] a) B. T. Parr, S. A. Green, H. M. L. Davies, J. Am.
Chem. Soc. 2013, 135, 4716; b) J. E. Spangler, H. M. L. Davies, J.
Am. Chem. Soc. 2013, 135, 6802; c) T. Miura, Y. Funakoshi, M.
Murakami, J. Am. Chem. Soc. 2014, 136, 2272; d) J.-M. Yang, C.-
Z. Zhu, X.-Y. Tang, M. Shi, Angew. Chem. Int. Ed. 2014, 53,
5142; Angew. Chem. 2014, 126, 5242; e) X.-Y. Tang, Y.-S. Zhang,
L. He, Y. Wei, M. Shi, Chem. Commun. 2015, 51, 133; f) S. Park,
W.-S. Yong, S. Kim, P. H. Lee, Org. Lett. 2014, 16, 4468; g) B.
Rajagopal, C.-H. Chou, C.-C. Chung, P.-C. Lin, Org. Lett. 2014,
16, 3752.
This method features a [3+2]/[5+2] annulation through dual
À
C H functionalization and represents the first straightfor-
ward procedure for the construction of the indeno[1,7-
cd]azepine architecture with excellent functional-group tol-
erance and good levels of selectivity. Further mechanistic
studies and applications of this rhodium(III)-catalyzed tri-
azole-annulation strategy are currently under way in our
laboratory.
[6] For other selected examples of the use of 1-sulfonyl-1,2,3-
triazoles as precursors of RhII azavinyl carbenes in synthesis, see:
a) S. Chuprakov, F. W. Hwang, V. Gevorgyan, Angew. Chem. Int.
Ed. 2007, 46, 4757; Angew. Chem. 2007, 119, 4841; b) T. Horneff,
S. Chuprakov, N. Chernyak, V. Gevorgyan, V. V. Fokin, J. Am.
Chem. Soc. 2008, 130, 14972; c) T. Miura, M. Yamauchi, M.
Murakami, Chem. Commun. 2009, 1470; d) M. Zibinsky, V. V.
Fokin, Angew. Chem. Int. Ed. 2013, 52, 1507; Angew. Chem.
2013, 125, 1547; e) S. Chuprakov, S. W. Kwok, V. V. Fokin, J. Am.
Chem. Soc. 2013, 135, 4652; f) B. T. Parr, H. M. L. Davies,
Angew. Chem. Int. Ed. 2013, 52, 10044; Angew. Chem. 2013, 125,
10228; g) J. S. Alford, J. E. Spangler, H. M. L. Davies, J. Am.
Chem. Soc. 2013, 135, 11712; h) T. Miura, K. Hiraga, T. Biyajima,
T. Nakamuro, M. Murakami, Org. Lett. 2013, 15, 3298; i) Y. Shi,
V. Gevorgyan, Org. Lett. 2013, 15, 5394; j) S. Chuprakov, B. T.
Worrell, N. Selander, R. K. Sit, V. V. Fokin, J. Am. Chem. Soc.
2014, 136, 195; k) S. W. Kwok, L. Zhang, N. P. Grimster, V. V.
Fokin, Angew. Chem. Int. Ed. 2014, 53, 3452; Angew. Chem.
2014, 126, 3520; l) C. Kim, S. Park, D. Eom, B. Seo, P. H. Lee,
Org. Lett. 2014, 16, 1900; m) D. J. Jung, H. J. Jeon, J. H. Kim, Y.
Kim, S. Lee, Org. Lett. 2014, 16, 2208; n) H. Shang, Y. Wang, Y.
Tian, J. Feng, Y. Tang, Angew. Chem. Int. Ed. 2014, 53, 5662;
Angew. Chem. 2014, 126, 5768.
Keywords: alkynes · annulation · indeno[1,7-cd]azepines ·
rhodium · triazoles
[1] a) T. Kametani, K. Fukumoto, Heterocycles 1975, 3, 931; b) B.
Renfroe, C. Harrington, G. R. Proctor, Heterocyclic Com-
pounds: Azepines, Wiley Interscience, New York, 1984;
c) C. R. Ganellin, D. J. Triggle, Dictionary of Pharmacological
Agents, Chapman & Hall/CRC, London, 1996.
[2] For hainanensine, see: a) N. J. Sun, X. T. Liang, Acta Pharmacol.
Sin. 1981, 16, 24; b) D. L. Yin, C. X. Xu, Y. S. Gao, D. K. Liu,
S. Y. Wen, J. Y. Guo, Acta Pharmacol. Sin. 1992, 27, 824; c) J. Y.
Guo, D. L. Yin, Y. S. Gao, D. K. Liu, X. T. Liang, Chin. J. Org.
Chem. 1993, 13, 195; d) Y. M. Ye, C. X. Xu, R. H. Sui, J. Y. Guo,
G. J. Cui, Acta Pharmacol. Sin. 1995, 30, 12; e) W. J. Zhang, T. H.
Zhou, Acta Pharmacol. Sin. 1998, 33, 212; f) R. D. Clark, K. K.
Weinhardt, J. Berger, L. E. Fisher, C. M. Brown, A. C. MacK-
innon, A. T. Kilpatrick, M. Spedding, J. Med. Chem. 1990, 33,
633; Cephalotaxine: g) L. Huang, Z. Xue in The Alkaloids,
Vol. 23 (Ed.: A. Brossi), Academic Press, New York, 1984,
pp. 157 – 226; h) T. Hudlicky, L. D. Kwart, J. W. Reed in
Alkaloids: Chemical and Biological Perspectives, Vol. 5 (Ed.:
S. W. Pelletier), Wiley, New York, 1987, pp. 639 – 690; i) M. A. J.
Miah, T. Hudlicky, J. W. Reed in The Alkaloids, Vol. 51 (Ed.: A.
Brossi), Academic Press, New York, 1998, pp. 199 – 269; for
zarebradine, see: j) R. E. BoSmith, I. Briggs, N. C. Sturgess, Br. J.
Pharmacol. 1993, 110, 343; k) G. Fliss, A. Staab, C. Tillmann, D.
Trommeshauser, H. G. Schaefer, C. Kloft, Pharm. Res. 2008, 25,
359; l) S. P. Glasser, D. D. Michie, U. Thadani, W. M. Baiker,
Am. J. Cardiol. 1997, 79, 1401; SCH23390: m) L. C. Iorio, A.
Barnett, F. H. Leitz, V. P. Houser, C. A. Korduba, Pharmacology
1983, 226, 462; for SKF 38393, see: n) R. G. Pendleton, L.
Samler, C. Kaiser, P. T. Ridley, Eur. J. Pharmacol. 1978, 51, 19;
o) P. G. Setler, H. M. Sarau, C. L. Zirkle, H. L. Saunders, Eur. J.
[7] For selected reviews, see: a) T. Satoh, M. Miura, Synthesis 2010,
3395; b) T. Satoh, M. Miura, Chem. Eur. J. 2010, 16, 11212;
c) F. W. Patureau, J. Wencel-Delord, F. Glorius, Aldrichimica
Acta 2012, 45, 31; d) G. Song, F. Wang, X. Li, Chem. Soc. Rev.
2012, 41, 3651; for representative examples of rhodium(III)-
2
À
catalyzed aryl C(sp ) H annulation with alkynes in the presence
of oxidants, see: e) D. R. Stuart, M. Bertrand-Laperle, K. M. N.
Burgess, K. Fagnou, J. Am. Chem. Soc. 2008, 130, 16474; f) N.
Guimond, K. Fagnou, J. Am. Chem. Soc. 2009, 131, 12050; g) T.
Fukutani, N. Umeda, K. Hirano, T. Satoh, M. Miura, Chem.
Commun. 2009, 5141; h) K. Morimoto, K. Hirano, T. Satoh, M.
Miura, Org. Lett. 2010, 12, 2068; i) F. W. Patureau, T. Besset, N.
Kuhl, F. Glorius, J. Am. Chem. Soc. 2011, 133, 2154; j) K.
Muralirajan, K. Parthasarathy, C.-H. Cheng, Angew. Chem. Int.
4
www.angewandte.org
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Angewandte
Chemie
Ed. 2011, 50, 4169; Angew. Chem. 2011, 123, 4255; k) J.
Jayakumar, K. Parthasarathy, C.-H. Cheng, Angew. Chem. Int.
Ed. 2012, 51, 197; Angew. Chem. 2012, 124, 201; l) B.-J. Li, H.-Y.
Wang, Q.-L. Zhu, Z.-J. Shi, Angew. Chem. Int. Ed. 2012, 51, 3948;
Angew. Chem. 2012, 124, 4014; m) X. Tan, B. Liu, X. Li, B. Li, S.
Xu, H. Song, B. Wang, J. Am. Chem. Soc. 2012, 134, 16163; n) J.
Jayakumar, K. Parthasarathy, Y.-H. Chen, T.-H. Lee, S.-C.
Chuang, C.-H. Cheng, Angew. Chem. Int. Ed. 2014, 53, 9889;
Angew. Chem. 2014, 126, 10047; o) M.-B. Zhou, R. Pi, M. Hu, Y.
Yang, R.-J. Song, Y. Xia, J.-H. Li, Angew. Chem. Int. Ed. 2014,
53, 11338; Angew. Chem. 2014, 126, 11520; p) S. Yu, X. Li, Org.
Lett. 2014, 16, 1200; q) K. Morimoto, M. Itoh, K. Hirano, T.
Satoh, Y. Shibata, K. Tanaka, M. Miura, Angew. Chem. Int. Ed.
2012, 51, 5359; Angew. Chem. 2012, 124, 5455; r) Y. Chen, F.
Wang, W. Zhen, X. Li, Adv. Synth. Catal. 2013, 355, 353.
can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
The structure of diastereoisomers 3 was determined by 2D NMR
spectroscopic analysis of 3aa and from the single-crystal
structure of 8aa (see Supporting Information).
[9] V. Narasimhan, R. Rathore, S. Chandrasekaran, Synth.
Commun. 1985, 15, 769.
[10] a) A. J. C. Walters, E. Jellema, M. Finger, P. Aarnoutse, J. M. M.
Smits, J. N. H. Reek, B. de Bruin, ACS Catal. 2012, 2, 246; b) S.
Yu, S. Liu, Y. Lan, B. Wan, X. Li, J. Am. Chem. Soc. 2015, 137,
1623.
[8] CCDC 1048349 (4gf) and CCDC 1048350 (8aa) contain the
supplementary crystallographic data for this paper. These data
Received: February 9, 2015
Published online: && &&, &&&&
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Communications
Synthetic Methods
Y. Yang, M.-B. Zhou, X.-H. Ouyang, R. Pi,
R.-J. Song, J.-H. Li*
&&&& — &&&&
Rhodium(III)-Catalyzed [3+2]/[5+2]
Annulation of 4-Aryl 1,2,3-Triazoles with
2
À
Internal Alkynes through Dual C(sp ) H
Functionalization
A quantum leap in complexity: A general
strategy based on rhodium(III) azavinyl
carbene intermediates was established
for the oxidative [3+2]/[5+2] annulation
of 4-aryl 1-tosyl-1,2,3-triazoles with
densely functionalized indeno[1,7-cd]aze-
pine architectures with excellent selectiv-
ity through the functionalization of two
2
À
C(sp ) H bonds (see scheme; Cp*=
pentamethylcyclopentadienyl, Ts=p-tol-
alkynes. This general method provided
uenesulfonyl).
6
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Angew. Chem. Int. Ed. 2015, 54, 1 – 6
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