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Angewandte Chemie - International Edition

Volumn 50, Issue 31, 2011, Pages 7162-7166

A simple and highly efficient iron catalyst for a [2+2+2] cycloaddition to form pyridines

(4) Wang, Chunxiang a Li, Xincheng a Wu, Fan a Wan, Boshun a

a DALIAN INSTITUTE OF CHEMICAL PHYSICS (China)

Author keywords

cycloaddition; heterocycles; iron; nitriles; pyridines

Indexed keywords

[2+2+2] CYCLOADDITION; DIPHOSPHINE LIGAND; HETEROCYCLES; HIGH REACTIVITY; IN-SITU; IRON CATALYST; IRON SALTS; NITRILES; ROOM TEMPERATURE;

CATALYSTS; CYANIDES; PYRIDINE;

IRON;

EID: 79960638576 PISSN: 14337851 EISSN: 15213773 Source Type: Journal
DOI: 10.1002/anie.201102001 Document Type: Article

Times cited : (164)

References (82)

1
- 3042558198
- G. D. Henry, Tetrahedron 2004, 60, 6043
- (2004) Tetrahedron , vol.60 , pp. 6043
- Henry, G.D.¹

2
- 78249271716
- references therein
- M. D. Hill, Chem. Eur. J. 2010, 16, 12052, and references therein.
- (2010) Chem. Eur. J. , vol.16 , pp. 12052
- Hill, M.D.¹

3
- 0001083027
- K. P. C. Vollhardt, Angew. Chem. 1984, 96, 525
- (1984) Angew. Chem. , vol.96 , pp. 525
- Vollhardt, K.P.C.¹

4
- 84985571853
- Angew. Chem. Int. Ed. Engl. 1984, 23, 539
- (1984) Angew. Chem. Int. Ed. Engl. , vol.23 , pp. 539

5
- 0000981574
- H. Bönnemann, Angew. Chem. 1985, 97, 264
- (1985) Angew. Chem. , vol.97 , pp. 264
- Bönnemann, H.¹

6
- 0022040955
- Angew. Chem. Int. Ed. Engl. 1985, 24, 248
- (1985) Angew. Chem. Int. Ed. Engl. , vol.24 , pp. 248

7
- 0141677747
- J. A. Varela, C. Saá, Chem. Rev. 2003, 103, 3787
- (2003) Chem. Rev. , vol.103 , pp. 3787
- Varela, J.A.¹ Saá, C.²

8
- 33845252502
- P. R. Chopade, J. Louie, Adv. Synth. Catal. 2006, 348, 2307
- (2006) Adv. Synth. Catal. , vol.348 , pp. 2307
- Chopade, P.R.¹ Louie, J.²

9
- 34250653953
- B. Heller, M. Hapke, Chem. Soc. Rev. 2007, 36, 1085
- (2007) Chem. Soc. Rev. , vol.36 , pp. 1085
- Heller, B.¹ Hapke, M.²

10
- 55449099596
- J. A. Varela, C. Saá, Synlett 2008, 2571
- (2008) Synlett , pp. 2571
- Varela, J.A.¹ Saá, C.²

11
- 79960643647
- G. Domínguez, J. Pérez-Castells, Chem. Soc. Rev. 2011, DOI:; see also.
- (2011) Chem. Soc. Rev.
- G. Domínguez¹

12
- 11144323895
- C. Bolm, J. Legros, J. L. Paih, L. Zani, Chem. Rev. 2004, 104, 6217
- (2004) Chem. Rev. , vol.104 , pp. 6217
- Bolm, C.¹ Legros, J.² Paih, J.L.³ Zani, L.⁴

13
- 69249201068
- C. Bolm, Nat. Chem. 2009, 1, 420
- (2009) Nat. Chem. , vol.1 , pp. 420
- Bolm, C.¹

14
- 44349129755
- A. Correa, O. G. Mancheño, C. Bolm, Chem. Soc. Rev. 2008, 37, 1108
- (2008) Chem. Soc. Rev. , vol.37 , pp. 1108
- Correa, A.¹ Mancheño, O.G.² Bolm, C.³

15
- 70350142896
- A. A. O. Sarhan, C. Bolm, Chem. Soc. Rev. 2009, 38, 2730
- (2009) Chem. Soc. Rev. , vol.38 , pp. 2730
- Sarhan, A.A.O.¹ Bolm, C.²

16
- 54849171100
- S. Enthaler, K. Junge, M. Beller, Angew. Chem. 2008, 120, 3363
- (2008) Angew. Chem. , vol.120 , pp. 3363
- Enthaler, S.¹ Junge, K.² Beller, M.³

17
- 50049109778
- Angew. Chem. Int. Ed. 2008, 47, 3317
- (2008) Angew. Chem. Int. Ed. , vol.47 , pp. 3317

18
- 65349113543
- A. Fürstner, Angew. Chem. 2009, 121, 1390
- (2009) Angew. Chem. , vol.121 , pp. 1390
- Fürstner, A.¹

19
- 60149095698
- Angew. Chem. Int. Ed. 2009, 48, 1364
- (2009) Angew. Chem. Int. Ed. , vol.48 , pp. 1364

20
- 57549083398
- B. D. Sherry, A. Fürstner, Acc. Chem. Res. 2008, 41, 1500
- (2008) Acc. Chem. Res. , vol.41 , pp. 1500
- Sherry, B.D.¹ Fürstner, A.²

21
- 57649165184
- E. B. Bauer, Curr. Org. Chem. 2008, 12, 1341
- (2008) Curr. Org. Chem. , vol.12 , pp. 1341
- Bauer, E.B.¹

22
- 77954946316
- L.-X. Liu, Curr. Org. Chem. 2010, 14, 1099
- (2010) Curr. Org. Chem. , vol.14 , pp. 1099
- Liu, L.-X.¹

23
- 79960651828
- O. García Mancheño, Angew. Chem. 2011, 123, 2264
- (2011) Angew. Chem. , vol.123 , pp. 2264
- García Mancheño, O.¹

24
- 79952052747
- Angew. Chem. Int. Ed. 2011, 50, 2216.
- (2011) Angew. Chem. Int. Ed. , vol.50 , pp. 2216

25
- 0013037986
- K. Ferré, L. Toupet, V. Guerchais, Organometallics 2002, 21, 2578
- (2002) Organometallics , vol.21 , pp. 2578
- Ferré, K.¹ Toupet, L.² Guerchais, V.³

26
- 0038214888
- U. Schmidt, U. Zenneck, J. Organomet. Chem. 1992, 440, 187
- (1992) J. Organomet. Chem. , vol.440 , pp. 187
- Schmidt, U.¹ Zenneck, U.²

27
- 0000066660
- F. Knoch, F. Kremer, U. Schmidt, U. Zenneck, P. L. Floch, F. Mathey, Organometallics 1996, 15, 2713
- (1996) Organometallics , vol.15 , pp. 2713
- Knoch, F.¹ Kremer, F.² Schmidt, U.³ Zenneck, U.⁴ Floch, P.L.⁵ Mathey, F.⁶

28
- 79957841769
- during proof correction of this manuscript, an iron-catalyzed [2+2+2] cycloaddition of an alkyne nitrile and an alkyne was reported; see:, B. R. D'Souza, T. K. Lane, J. Louie, Org. Lett. 2011, 13, 2936.
- (2011) Org. Lett. , vol.13 , pp. 2936
- D'Souza, B.R.¹ Lane, T.K.² Louie, J.³

29
- 0347619471
- A. Naiman, K. P. C. Vollhardt, Angew. Chem. 1977, 89, 758
- (1977) Angew. Chem. , vol.89 , pp. 758
- Naiman, A.¹ Vollhardt, K.P.C.²

30
- 84980156703
- Angew. Chem. Int. Ed. Engl. 1977, 16, 708
- (1977) Angew. Chem. Int. Ed. Engl. , vol.16 , pp. 708

31
- 0039007933
- D. J. Brien, A. Naiman, K. P. C. Vollhardt, J. Chem. Soc. Chem. Commun. 1982, 133
- (1982) J. Chem. Soc. Chem. Commun. , pp. 133
- Brien, D.J.¹ Naiman, A.² Vollhardt, K.P.C.³

32
- 37049116387
- Y. Wakatsuki, H. Yamazaki, J. Chem. Soc. Chem. Commun. 1973, 280a
- (1973) J. Chem. Soc. Chem. Commun.
- Wakatsuki, Y.¹ Yamazaki, H.²

33
- 0001680749
- J. A. Varela, L. Castedo, C. Saá, J. Org. Chem. 1997, 62, 4189
- (1997) J. Org. Chem. , vol.62 , pp. 4189
- Varela, J.A.¹ Castedo, L.² Saá, C.³

34
- 0001616654
- J. A. Varela, L. Castedo, C. Saá, Org. Lett. 1999, 1, 2141
- (1999) Org. Lett. , vol.1 , pp. 2141
- Varela, J.A.¹ Castedo, L.² Saá, C.³

35
- 0034609693
- A. W. Fatland, B. E. Eaton, Org. Lett. 2000, 2, 3131
- (2000) Org. Lett. , vol.2 , pp. 3131
- Fatland, A.W.¹ Eaton, B.E.²

36
- 0345686500
- B. Heller, B. Sundermann, C. Fischer, J. S. You, W. Q. Chen, H. J. Drexler, P. Knochel, B. Bonrath, A. Gutnov, J. Org. Chem. 2003, 68, 9221
- (2003) J. Org. Chem. , vol.68 , pp. 9221
- Heller, B.¹ Sundermann, B.² Fischer, C.³ You, J.S.⁴ Chen, W.Q.⁵ Drexler, H.J.⁶ Knochel, P.⁷ Bonrath, B.⁸ Gutnov, A.⁹

37
- 11144324670
- A. Gutnov, B. Heller, C. Fischer, H.-J. Drexler, A. Spannenberg, B. Sundermann, C. Sundermann, Angew. Chem. 2004, 116, 3883
- (2004) Angew. Chem. , vol.116 , pp. 3883
- Gutnov, A.¹ Heller, B.² Fischer, C.³ Drexler, H.-J.⁴ Spannenberg, A.⁵ Sundermann, B.⁶ Sundermann, C.⁷

38
- 4544286694
- Angew. Chem. Int. Ed. 2004, 43, 3795
- (2004) Angew. Chem. Int. Ed. , vol.43 , pp. 3795

39
- 18744415776
- A. Gutnov, V. Abaev, D. Redkin, C. Fischer, W. Bonrath, B. Heller, Synlett 2005, 7, 1188
- (2005) Synlett , vol.7 , pp. 1188
- Gutnov, A.¹ Abaev, V.² Redkin, D.³ Fischer, C.⁴ Bonrath, W.⁵ Heller, B.⁶

40
- 0034826606
- A. F. Moretto, H.-C. Zhang, B. E. Maryanoff, J. Am. Chem. Soc. 2001, 123, 3157
- (2001) J. Am. Chem. Soc. , vol.123 , pp. 3157
- Moretto, A.F.¹ Zhang, H.-C.² Maryanoff, B.E.³

41
- 14944380049
- L. V. R. Boñaga, H.-C. Zhang, A. F. Moretto, H. Ye, D. A. Gauthier, J. Li, G. C. Leo, B. E. Maryanoff, J. Am. Chem. Soc. 2005, 127, 3473
- (2005) J. Am. Chem. Soc. , vol.127 , pp. 3473
- Boñaga, L.V.R.¹ Zhang, H.-C.² Moretto, A.F.³ Ye, H.⁴ Gauthier, D.A.⁵ Li, J.⁶ Leo, G.C.⁷ Maryanoff, B.E.⁸

42
- 33847030361
- H.-T. Chang, M. Jeganmohan, C.-H. Cheng, Org. Lett. 2007, 9, 505
- (2007) Org. Lett. , vol.9 , pp. 505
- Chang, H.-T.¹ Jeganmohan, M.² Cheng, C.-H.³

43
- 33947147688
- K. Kase, A. Goswami, K. Ohtaki, E. Tanabe, N. Saino, S. Okamoto, Org. Lett. 2007, 9, 931
- (2007) Org. Lett. , vol.9 , pp. 931
- Kase, K.¹ Goswami, A.² Ohtaki, K.³ Tanabe, E.⁴ Saino, N.⁵ Okamoto, S.⁶

44
- 38349131987
- A. Goswami, K. Ohtaki, K. Kase, T. Ito, S. Okamoto, Adv. Synth. Catal. 2008, 350, 143
- (2008) Adv. Synth. Catal. , vol.350 , pp. 143
- Goswami, A.¹ Ohtaki, K.² Kase, K.³ Ito, T.⁴ Okamoto, S.⁵

45
- 33847058832
- Y. Zhou, J. A. Porco, J. K. Snyder, Org. Lett. 2007, 9, 393
- (2007) Org. Lett. , vol.9 , pp. 393
- Zhou, Y.¹ Porco, J.A.² Snyder, J.K.³

46
- 53849100381
- D. D. Young, A. Deiters, Angew. Chem. 2007, 119, 5279
- (2007) Angew. Chem. , vol.119 , pp. 5279
- Young, D.D.¹ Deiters, A.²

47
- 34447298389
- Angew. Chem. Int. Ed. 2007, 46, 5187
- (2007) Angew. Chem. Int. Ed. , vol.46 , pp. 5187

48
- 77955148401
- A. Geny, N. Agenet, L. Iannazzo, M. Malacria, C. Aubert, V. Gandon, Angew. Chem. 2009, 121, 1842
- (2009) Angew. Chem. , vol.121 , pp. 1842
- Geny, A.¹ Agenet, N.² Iannazzo, L.³ Malacria, M.⁴ Aubert, C.⁵ Gandon, V.⁶

49
- 61349084243
- Angew. Chem. Int. Ed. 2009, 48, 1810
- (2009) Angew. Chem. Int. Ed. , vol.48 , pp. 1810

50
- 60749134158
- P. Garcia, S. Moulin, Y. Miclo, D. Leboeuf, V. Gandon, C. Aubert, M. Malacria, Chem. Eur. J. 2009, 15, 2129
- (2009) Chem. Eur. J. , vol.15 , pp. 2129
- Garcia, P.¹ Moulin, S.² Miclo, Y.³ Leboeuf, D.⁴ Gandon, V.⁵ Aubert, C.⁶ Malacria, M.⁷

51
- 77951670047
- C. Yuan, C.-T. Chang, A. Axelrod, D. Siegel, J. Am. Chem. Soc. 2010, 132, 5924
- (2010) J. Am. Chem. Soc. , vol.132 , pp. 5924
- Yuan, C.¹ Chang, C.-T.² Axelrod, A.³ Siegel, D.⁴

52
- 77957662128
- M. Hapke, N. Weding, A. Spannenberg, Organometallics 2010, 29, 4298
- (2010) Organometallics , vol.29 , pp. 4298
- Hapke, M.¹ Weding, N.² Spannenberg, A.³

53
- 77953492952
- M. Hapke, K. Kral, C. Fischer, A. Spannenberg, A. Gutnov, D. Redkin, B. Heller, J. Org. Chem. 2010, 75, 3993.
- (2010) J. Org. Chem. , vol.75 , pp. 3993
- Hapke, M.¹ Kral, K.² Fischer, C.³ Spannenberg, A.⁴ Gutnov, A.⁵ Redkin, D.⁶ Heller, B.⁷

54
- 0034820132
- Y. Yamamoto, R. Ogawa, K. Itoh, J. Am. Chem. Soc. 2001, 123, 6189
- (2001) J. Am. Chem. Soc. , vol.123 , pp. 6189
- Yamamoto, Y.¹ Ogawa, R.² Itoh, K.³

55
- 0035927877
- Y. Yamamoto, S. Okuda, K. Itoh, Chem. Commun. 2001, 1102
- (2001) Chem. Commun. , pp. 1102
- Yamamoto, Y.¹ Okuda, S.² Itoh, K.³

56
- 12944303660
- Y. Yamamoto, K. Kinpara, T. Saigoku, H. Takagishi, S. Okuda, H. Nishiyama, K. Itoh, J. Am. Chem. Soc. 2005, 127, 605
- (2005) J. Am. Chem. Soc. , vol.127 , pp. 605
- Yamamoto, Y.¹ Kinpara, K.² Saigoku, T.³ Takagishi, H.⁴ Okuda, S.⁵ Nishiyama, H.⁶ Itoh, K.⁷

57
- 29144506116
- Y. Yamamoto, K. Kinpara, H. Nishiyama, K. Itoh, Adv. Synth. Catal. 2005, 347, 1913
- (2005) Adv. Synth. Catal. , vol.347 , pp. 1913
- Yamamoto, Y.¹ Kinpara, K.² Nishiyama, H.³ Itoh, K.⁴

58
- 33746299182
- Y. Yamamoto, K. Kinpara, R. Ogawa, H. Nishiyama, K. Itoh, Chem. Eur. J. 2006, 12, 5618
- (2006) Chem. Eur. J. , vol.12 , pp. 5618
- Yamamoto, Y.¹ Kinpara, K.² Ogawa, R.³ Nishiyama, H.⁴ Itoh, K.⁵

59
- 0142258960
- J. A. Varela,., L. Castedo, C. Saá, J. Org. Chem. 2003, 68, 8595.
- (2003) J. Org. Chem. , vol.68 , pp. 8595
- Varela, J.A.¹ Castedo, L.² Saá, C.³

60
- 33748550638
- K. Tanaka, N. Suzuki, G. Nishida, Eur. J. Org. Chem. 2006, 3917
- (2006) Eur. J. Org. Chem. , pp. 3917
- Tanaka, K.¹ Suzuki, N.² Nishida, G.³

61
- 34249283376
- K. Tanaka, H. Hara, G. Nishda, M. Hirano, Org. Lett. 2007, 9, 1907
- (2007) Org. Lett. , vol.9 , pp. 1907
- Tanaka, K.¹ Hara, H.² Nishda, G.³ Hirano, M.⁴

62
- 34147113797
- A. Wada, K. Noguchi, M. Hirano, K. Tanaka, Org. Lett. 2007, 9, 1295
- (2007) Org. Lett. , vol.9 , pp. 1295
- Wada, A.¹ Noguchi, K.² Hirano, M.³ Tanaka, K.⁴

63
- 69449085237
- T. Shibata, T. Uchiyama, K. Endo, Org. Lett. 2009, 11, 3906
- (2009) Org. Lett. , vol.11 , pp. 3906
- Shibata, T.¹ Uchiyama, T.² Endo, K.³

64
- 77949831892
- Y. Komine, K. Tanaka, Org. Lett. 2010, 12, 1312.
- (2010) Org. Lett. , vol.12 , pp. 1312
- Komine, Y.¹ Tanaka, K.²

65
- 17144426927
- M. M. McCormick, H. A. Duong, G. Zuo, J. Louie, J. Am. Chem. Soc. 2005, 127, 5030
- (2005) J. Am. Chem. Soc. , vol.127 , pp. 5030
- McCormick, M.M.¹ Duong, H.A.² Zuo, G.³ Louie, J.⁴

66
- 33746375065
- T. N. Tekavec, G. Zuo, K. Simon, J. Louie, J. Org. Chem. 2006, 71, 5834
- (2006) J. Org. Chem. , vol.71 , pp. 5834
- Tekavec, T.N.¹ Zuo, G.² Simon, K.³ Louie, J.⁴

67
- 79960635077
- R. M. Stolley, M. T. Maczka, J. Louie, Eur. J. Org. Chem. DOI:.
- Eur. J. Org. Chem.
- Stolley, R.M.¹ MacZka, M.T.² Louie, J.³

68
- 0037051610
- D. Suzuki, R. Tanaka, H. Urabe, F. Sato, J. Am. Chem. Soc. 2002, 124, 3518
- (2002) J. Am. Chem. Soc. , vol.124 , pp. 3518
- Suzuki, D.¹ Tanaka, R.² Urabe, H.³ Sato, F.⁴

69
- 19744370350
- D. Suzuki, Y. Nobe, Y. Watai, R. Tanaka, Y. Takayama, F. Sato, H. Urabe, J. Am. Chem. Soc. 2005, 127, 7474
- (2005) J. Am. Chem. Soc. , vol.127 , pp. 7474
- Suzuki, D.¹ Nobe, Y.² Watai, Y.³ Tanaka, R.⁴ Takayama, Y.⁵ Sato, F.⁶ Urabe, H.⁷

70
- 19744363604
- R. Tanaka, A. Yuza, Y. Watai, D. Suzuki, Y. Takayama, F. Sato, H. Urabe, J. Am. Chem. Soc. 2005, 127, 7774.
- (2005) J. Am. Chem. Soc. , vol.127 , pp. 7774
- Tanaka, R.¹ Yuza, A.² Watai, Y.³ Suzuki, D.⁴ Takayama, Y.⁵ Sato, F.⁶ Urabe, H.⁷

71
- 0034709381
- T. Takahashi, F.-Y. Tsai, K. Martin, J. Am. Chem. Soc. 2000, 122, 4994
- (2000) J. Am. Chem. Soc. , vol.122 , pp. 4994
- Takahashi, T.¹ Tsai, F.-Y.² Martin, K.³

72
- 0037042297
- T. Takahashi, F.-Y. Tsai, Y. Li, H. Wang, Y. Kondo, M. Yamanaka, K. Nakajima, M. Kotora, J. Am. Chem. Soc. 2002, 124, 5059
- (2002) J. Am. Chem. Soc. , vol.124 , pp. 5059
- Takahashi, T.¹ Tsai, F.-Y.² Li, Y.³ Wang, H.⁴ Kondo, Y.⁵ Yamanaka, M.⁶ Nakajima, K.⁷ Kotora, M.⁸

73
- 61349167250
- L. Zhou, M. Yamanaka, K.-I. Kanno, T. Takahashi, Heterocycles 2008, 76, 923.
- (2008) Heterocycles , vol.76 , pp. 923
- Zhou, L.¹ Yamanaka, M.² Kanno, K.-I.³ Takahashi, T.⁴

74
- 78649932201
- Only benzene-type products were formed in good to excellent yields, for details please see:, Y. Liu, X. Yan, N. Yang, C. Xi, Catal. Commun. 2011, 12, 489.
- (2011) Catal. Commun. , vol.12 , pp. 489
- Liu, Y.¹ Yan, X.² Yang, N.³ Xi, C.⁴

75
- 0011749982
- A ferracyclopentadiene intermediate was previously isolated and characterized:, U. Zenneck, Angew. Chem. 1990, 102, 171
- (1990) Angew. Chem. , vol.102 , pp. 171
- Zenneck, U.¹

76
- 0025266247
- Angew. Chem. Int. Ed. Engl. 1990, 29, 126.
- (1990) Angew. Chem. Int. Ed. Engl. , vol.29 , pp. 126

77
- 0004582720
- C. Breschi, L. Piparo, P. Pertici, A. M. Caporusso, G. Vitulli, J. Organomet. Chem. 2000, 607, 57
- (2000) J. Organomet. Chem. , vol.607 , pp. 57
- Breschi, C.¹ Piparo, L.² Pertici, P.³ Caporusso, A.M.⁴ Vitulli, G.⁵

78
- 22244460188
- N. Saino, D. Kogure, S. Okamoto, Org. Lett. 2005, 7, 3065
- (2005) Org. Lett. , vol.7 , pp. 3065
- Saino, N.¹ Kogure, D.² Okamoto, S.³

79
- 33745127330
- N. Saino, D. Dogure, K. Kase, S. Okamoto, J. Organomet. Chem. 2006, 691, 3129
- (2006) J. Organomet. Chem. , vol.691 , pp. 3129
- Saino, N.¹ Dogure, D.² Kase, K.³ Okamoto, S.⁴

80
- 39049167809
- A. Fürstner, K. Majima, R. Martín, H. Krause, E. Katting, R. Goddard, C. W. Lehmann, J. Am. Chem. Soc. 2008, 130, 1992; also see Ref. [11].
- (2008) J. Am. Chem. Soc. , vol.130 , pp. 1992
- Fürstner, A.¹ Majima, K.² Martín, R.³ Krause, H.⁴ Katting, E.⁵ Goddard, R.⁶ Lehmann, C.W.⁷

81
- 33746897342
- Y. Yu, J. M. Smith, F. C. Flaschenriem, P. L. Holland, Inorg. Chem. 2006, 45, 5742.
- (2006) Inorg. Chem. , vol.45 , pp. 5742
- Yu, Y.¹ Smith, J.M.² Flaschenriem, F.C.³ Holland, P.L.⁴

82
- 3342989847
- The large size difference between the terminal substituents plays a crucial role in the regioselectivity of these cycloaddition reactions; for details please see Ref. [5 m] and, T. N. Tekavec, A. M. Arif, J. Louie, Tetrahedron 2004, 60, 7431.
- (2004) Tetrahedron , vol.60 , pp. 7431
- Tekavec, T.N.¹ Arif, A.M.² Louie, J.³

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