DOI: 10.1039/C6CC04461A
ChemComm
A.11a The active Ru(II) acetate C reacts with acid B to form α-oxo
phenyl carboxylate- Ru complex D irreversibly. This is supported
by the preferential formation of 3de in the competition reaction
between 1c, 1d and 2e (Scheme 2), as the initial formation of
complex D might be easier for more acidic substrate 1d. This
Bechtoldt, C. Tirler, K. Raghuvanshi, S. Warratz, C. Kornhaaß, and
L. Ackermann, Angew. Chem., Int. Ed. 2016, 55, 264.
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70
75
80
4. For selected oxidizing directing groups used in Ru-, Rh- and Pd-
catalyzed C-H functionalization, see: (a) R. K. Chinnagolla, S.
Pimparkar and M. Jeganmohan, Org. Lett., 2012, 14, 3032; (b) B. Li,
H. Feng, S. Xu and B. Wang, Chem. Eur. J., 2011, 17, 12573; (c) L.
Ackermann and S. Fenner, Org. Lett., 2011, 13, 6548; (d) J. Mo, L.
Wang and X. Cui, Org. Lett., 2015, 17, 4960; (e) G. Liu, Y. Shen, Z.
Zhou and X. Lu, Angew. Chem., Int. Ed., 2013, 52, 6033; (f) T. K.
Hyster, K. E. Ruhl and T. Rovis, J. Am. Chem. Soc., 2013, 135, 5364;
(g) X. Huang, J. Huang, C. Du, X. Zhang, F. Song and J. You,
Angew. Chem., Int. Ed., 2013, 52, 12970; (h) S. Rakshit, C.
Grohmann, T. Besset and F. Glorius, J. Am. Chem. Soc., 2011, 133,
2350; (i) H. Wang, C. Grohmann, C. Nimphius and F. Glorius, J. Am.
Chem. Soc., 2012, 134, 19592; (j) Y. Tan and J. F. Hartwig, J. Am.
Chem. Soc., 2010, 132, 3676; (k) J. Wu, X. Cui, L. Chen, G. Jiang
and Y. Wu, J. Am. Chem. Soc., 2009, 131, 13888; (l) For a highlight,
see: F. W. Patureau and F. Glorius, Angew. Chem., Int. Ed., 2011, 50,
1977; Angew. Chem., 2011, 123, 2021; (m) C. Kornhaaß, C. Kuper
and L. Ackermann, Adv. Synth. Catal., 2014, 356, 1619; (n) F. Yang
and L. Ackermann, J. Org. Chem., 2014, 79, 12070.
85 5. S. Yu, S. Liu, Y. Lan, B. Wan and X. Li, J. Am. Chem. Soc., 2015,
137, 1623.
6. (a) R. Prakash, K. Shekarrao and S. Gogoi, Org. Lett., 2015, 17, 5264;
(b) R. Prakash, K. Shekarrao, S. Gogoi and R. C. Boruah, Chem.
Commun., 2015, 51, 9972.
90 7. R. Zeng and G. Dong, J. Am. Chem. Soc., 2015, 137, 1408.
8. (a) V. Subramanian, V. Rao Batchu, D. Barange and M. Pal, J. Org.
Chem., 2005, 70, 4778; (b) R. Rossi, A. Carpita, F. Bellina, P. Stabile
and L. Mannina, Tetrahedron, 2003, 59, 2067; (c) M. S. A. El-Gaby,
M. M. Ghorab and S. M. Abdel-Gawad, Acta Pharm., 1999, 49, 257;
5
complex
D on reversible cycloruthenation forms the six-
membered metalacycle E, which on coodinative alkyne insertion
reaction generates intermediate F.11b In the presence of O2 of air,
F forms intermediate G by releasing CO2 (detected by IR
10 spectroscopy), which on further oxidation provides Ru(IV)
species H by the cleavage of the cyclic O−O bond.11b-d Finally,
reductive elimination generates the product 3 and regenerates the
Ru(II) catalyst.
In summary, we have designed isatins as novel but readily
15 available substrates for external oxidant free C-H activation and
annulation reaction with alkynes to prepare 8-amido
isocoumarins. In this Ru(II)-catalyzed reaction, the amide C-N
bond of isatin acts as an oxidizing directing group to facilitate
4C-H activation of isatin. Considering the valuable structure of
20 the products, the broad substrate scope, less catalyst loading,
simple experimental procedure, high regioselectivity with some
unsymmetrical alkynes and good functionality tolerance, this
reaction should be of synthetic utility.
25 Acknowledgements
P. P. Kaishap thanks UGC for the fellowship. Authors thank
SERB, New Delhi, for financially supporting us with GPP-0303
(YSS/2014/001018) project. We are grateful to the Director,
CSIR-NEIST for his keen interests.
95
(d) S. S. Hadida-Ruah, X. He and J. Y. Nagasawa, PCT Int.
Appl., 2004, WO2004110385 A2; (e) M. G. Kelly, J. Kincaid, Y.
Fang, Y. Cao, C. Kaub, S. Gowlugari and Z. Wang, PCT Int.
Appl., 2007, WO2007109172 A2; (f) D. P. Jr. Griswold, A. E. Casey,
E. K. Weisburger, J. H. Weisburger and F. M. Jr. Schabel, Cancer
Res., 1966, 4, 619; (g) A. Banerjee, S. K. Santra, P. R. Mohanta and
B. K. Patel, Org. Lett., 2015, 17, 5678; For Ru(II)-catalyzed
ref. 3a.
100
30 Notes and references
aChemical Science & Technology Division, CSIR-North East Institute of
Science and Technology, Jorhat-785006, AcSIR, India, Fax:
.bDepartment of Chemical Sciences, Tezpur University, Napaam, Tezpur–
35 784028, India
† Electronic Supplementary Information (ESI) available: Experimental
procedures, characterization data, 1H and 13C NMR spectra of synthesized
compounds. See DOI:
105 9. (a) W. Dong, L. Wang, K. Parthasarathy, F. Pan and C. Bolm, Angew.
Chem., Int. Ed., 2013, 52, 11573; Angew. Chem., 2013, 125, 11787;
(b) A. Seoane, N. Casanova . ui ones . . ascare as and M.
Gulías, J. Am. Chem. Soc., 2014, 136, 834; (c) H. Shiota, Y. Ano, Y.
Aihara, Y. Fukumoto and N. Chatani, J. Am. Chem. Soc., 2011, 133,
110
14952; (d) L. Grigorjeva and O. Daugulis, Angew. Chem., Int. Ed.,
2014, 53, 10209; Angew. Chem., 2014, 126, 10373; (e) M. Deponti,
S. I. Kozhushkov, D. S. Yufitb and L. Ackermann, Org. Biomol.
Chem., 2013, 11, 142; (f) L. Ackermann, A. V. Lygin and N.
Hofmann, Angew. Chem., Int. Ed. 2011, 50, 6379.
1. For recent reviews on C-H activation, see: (a) J. Wencel-Delord and
40
45
50
55
60
F. Glorius, Nat. Chem., 2013, 5, 369; (b) N. Kuhl, M. N. Hopkinson,
J. Wencel-Delord and F. Glorius, Angew. Chem., Int. Ed. 2012, 51,
10236; Angew. Chem., 2012, 124, 10382; (c) M. C. White, Science
2012, 335, 807; (d) L. Ackermann, Chem. Rev. 2011, 111, 1315; (e)
P. L. Arnold, M. W. McMullon, J. Rieb and F. E. Kühn, Angew.
Chem., Int. Ed. 2015, 54, 82; Angew. Chem., 2015, 127, 84.
115 10. CCDC 1476263 contains the supplementary crystallographic data of
compound 3ae. These data are provided free of charge by The
Cambridge Crystallographic Data Centre.
2. For selected recent reviews and examples of Pd-, Rh-, Ru-catalyzed
C-H activations, see: (a) L. Wang, J. Huang, S. Peng, H. Liu, X.
Jiang and J. Wang, Angew. Chem., Int. Ed. 2013, 52, 1768; Angew.
Chem., 2013, 125, 1812; (b) C. S. Yeung and V. M. Dong, Chem.
Rev., 2011, 111, 1215; (c) R. Shintani, H. Otomo, K. Ota and T.
Hayashi, J. Am. Chem. Soc., 2012, 134, 7305; (d) L. Ackermann, L.
Wang and A. V. Lygin, Chem. Sci., 2012, 3, 177; (e) E. Ferrer
Flegeau, C. Bruneau, P. H. Dixneuf and A. Jutand, J. Am. Chem.
Soc., 2011, 133, 10161; (f) N. Kuhl, M. N. Hopkinson, J. Wencel-
Delord and F. Glorius, Angew. Chem., Int. Ed. 2012, 51, 10236; (g) J.
Wencel-Delord and F. Glorius, Nat. Chem., 2013, 5, 369; (h) P. B.
Arockiam, C. Bruneau and P. H. Dixneuf, Chem. Rev., 2012, 112,
5879; (i) J.-Q. Wu, Z. Yang, S.-S. Zhang, C.-Y. Jiang, Q. Li, Z.-S.
Huang and H. Wang, ACS Catal., 2015, 5, 6453; (j) L. Ackermann,
Acc. Chem. Res., 2014, 47, 281; (k) X.-S. Zhang, K. Chen and Z.-J.
Shi, Chem. Sci., 2014, 5, 2146.
11. (a) N. Poomathi, S. Mayakrishnan, D. Muralidharan, R. Srinivasanb
and P. T. Perumal, Green Chem., 2015, 17, 3362; (b) H. Tan, H. Li,
120
J. Wang and L. Wang, Chem. Eur. J., 2015, 21, 1904; (c) Z. Zhang,
H. Jiang and Y. Huang, Org. Lett., 2014, 16, 5976; (d) J. Mo, L.
Wang, and X. Cui, Org. Lett., 2015, 17, 4960; (e) Q. Song, Q. Feng,
and M. Zhou, Org. Lett., 2013, 15, 5990.
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