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Synlett 2009(1): 122-126
DOI: 10.1055/s-0028-1087386
DOI: 10.1055/s-0028-1087386
LETTER
© Georg Thieme Verlag
Stuttgart ˙ New York
Synthesis of 4-Acetoxyindoles and Related Derivatives by Means of Air Oxidation of 4-Oxo-4,5,6,7-tetrahydroindoles Obtained from Nitroalkenes and Cyclohexane-1,3-diones
Weitere Informationen
Received
28 July 2008
Publikationsdatum:
12. Dezember 2008 (online)
Publikationsverlauf
Publikationsdatum:
12. Dezember 2008 (online)
![](https://www.thieme-connect.de/media/synlett/200901/lookinside/thumbnails/10.1055-s-0028-1087386-1.jpg)
Abstract
A novel method for synthesizing 4-hydroxyindole derivatives from cyclohexane-1,3-diones and nitroalkenes have been developed in which a newly developed air oxidation of 4-oxo-4,5,6,7-tetrahydroindoles is playing a crucial role.
Key words
indoles - cyclohexane-1,3-diones - nitroalkenes - Michael additions - oxidations
- Supporting Information for this article is available online:
- Supporting Information
- For recent syntheses for 4-hydroxyindoles, see:
-
1a
Gathergood N.Scammells PJ. Org. Lett. 2003, 5: 921 -
1b
Shirota O.Hakamata W.Goda Y. J. Nat. Prod. 2003, 66: 885 ; and references cited therein -
1c For the structure-activity
relationship study of II, see:
Repke DB.Grotjahn DB.Shulgin AT. J. Med. Chem. 1985, 28: 892 - 2
Liou J.-P.Wu Z.-Y.Kuo C.-C.Chang C.-Y.Lu P.-Y.Chen C.-M.Hsieh H.-P.Chang J.-Y. J. Med. Chem. 2008, 51: 4351 -
3a
Ishikawa T.Kadoya R.Arai M.Takahashi H.Kaisi Y.Mizuta T.Yoshikai K.Saito S. J. Org. Chem. 2001, 66: 8000 -
3b
Ishikawa T.Miyahara T.Asakura M.Higuchi S.Miyauchi Y.Saito S. Org. Lett. 2005, 7: 1211 - 4 For KF-catalyzed synthesis of 2-hydroxyiminodihydro-furans,
see:
Miyashita M.Kumazawa T.Yoshikoshi A. J. Org. Chem. 1980, 45: 2945 - 5
Yanami T.Ballatore A.Miyashita M.Kato M.Yoshikoshi A. J. Chem. Soc., Perkin Trans. 1 1978, 1144 - For the synthesis of 4-oxo-4,5,6,7-tetrahydroindoles, see:
-
6a
Leonarda P.Chiara G.Giacomo M.Maurizio T. Tetrahedron Lett. 2008, 49: 459 -
6b
Kathriarachchi KKADS.Siriwardana AI.Nakamura I.Yamamoto Y. Tetrahedron Lett. 2007, 48: 2267 -
6c
Nayyar NK.Hutchison DR.Martinelli MJ. J. Org. Chem. 1997, 62: 982 -
6d
Matsumoto M.Watanabe N. Heterocycles 1984, 22: 2313 -
6e
Bobbitt JM.Kulkarni CL.Dutta CP.Kofod H.Chiong KN. J. Org. Chem. 1978, 43: 3541 - 7 4-Oxo-4,5,6,7-tetrahydroindoles with
no substituent at C(3) can be converted into 4-hydroxyindoles by
Pd-catalyzed dehydrogenation or DDQ oxidation though in low yields, see:
Remers WA.Roth RH.Gibs GJ.Weis MJ.
J. Org. Chem. 1971, 36: 1232 - For aromatization of six-membered carbocycles by air oxidation, see:
-
8a
Kawashita Y.Nakamichi N.Kawabata H.Hayashi M. Org. Lett. 2003, 5: 3713 -
8b
Ishikawa T.Hino K.Yoneda T.Murota M.Yamaguchi K.Watanabe T. J. Org. Chem. 1999, 64: 5691 - For the synthesis of 4-hydroxyindoles, see:
-
9a
Somei M.Yamada F. Heterocycles 2000, 53: 1573 -
9b
Matsumoto M.Ishoda Y.Watanabe N. Heterocycles 1986, 24: 165 -
9c
Hegedus LS.Mulhern TA.Mori A. J. Org. Chem. 1985, 50: 4282 -
9d
Remers WA.Weiss MJ. J. Am. Chem. Soc. 1965, 87: 5262 - 11
Schreiber SL. Science 2000, 287: 1964
References and Notes
We are considering that transformation of I-A to I-C may involve an intermediary adduct I-B although nucleophilic attack of electron-rich dienamine function in I-A toward oxygen molecule, if any, might directly give I-C from I-A and could not be ruled out.
12For general synthesis of cyclohexane-1,3-diones, see ref. 3a.
Table 5 Synthesis
of 3-Substituted 4-Acetoxyindolines via Air Oxidation |
|
![]() | |||||||||||||||||||
Entry | Hydroindoles 10 |
Indoline 11 (yield, %) | |||||||||||||||||
|
|||||||||||||||||||
1 | 10a |
![]() | 11a (59) | ||||||||||||||||
2 | 10b |
![]() | 11b (63) | ||||||||||||||||
3 | 10c |
![]() | 11c (28) | ||||||||||||||||
4 | 10d |
![]() | 11d (33) | ||||||||||||||||
5 | 10e |
![]() | 11e (54) | ||||||||||||||||
6 | 10f |
![]() | 11f (42) | ||||||||||||||||
|