Abstract
A straightforward reaction sequence consisting of a Sonogashira coupling of protected propargylic amines, a cobalt-catalysed neutral Diels-Alder reaction, DDQ oxidation of the dihydroaromatic intermediate, a sodium borohydride reduction and an acid induced Friedel-Crafts-type cyclisation approach incorporating four simple starting materials leads to polyfunctionalised polycyclic products. Based on the electronic, steric and structural preconditions either seven-membered dibenzoazepine derivatives or alternatively six- or eight-membered isoindoline derivatives are formed.
Key words
cobalt - Diels-Alder - cyclisation - Friedel-Crafts - heterocycles
References
Selected references for biologically activities of isoindole derivatives, see:
1a
De Clercq E.
J. Med. Chem.
1995,
38:
2491
1b
Ferland JM.
Demerson CA.
Humber LG.
Can. J. Chem.
1985,
63:
361
1c
Linden M.
Hadler D.
Hofmann S.
Hum. Psychopharmacol.
1997,
12:
445
1d
Zhuang ZP.
Kung MP.
Mu M.
Kung HF.
J. Med Chem.
1998,
41:
157
1e
Norman MH.
Minick DJ.
Rigdon GC.
J. Med. Chem.
1996,
39:
149
1f
Li S.
Wang X.
Guo H.
Chen L.
Yiyano Gongye
1985,
16:
543 ; Chem. Abstr. 1986, 105, 6378n
1g inventors; Laboratori Baldacci S.p.A. Japanese Patent 5,946,268.
; Chem. Abstr. 1984, 101, 54922
1h Lippmann W. inventors; U.S. Patent 4,267,189.
; Chem. Abstr. 1981, 95, 61988m
1i Achinami K, Ashizawa N, and Kobayasui F. inventors; Japanese Patent 03,133,955.
; Chem. Abstr. 1991, 115, 255977j
2a
Govindachari TR.
Ravindranath KR.
Viswanathan N.
J. Chem. Soc., Perkin Trans. 1
1974,
1215
2b
Pendrack I.
Barney S.
Wittrock R.
Lambert DM.
Kingsbury WD.
J. Org. Chem.
1994,
59:
2623
2c
Taylor EC.
Zhou P.
Jenning LD.
Mao Z.
Hu B.
Jun JG.
Tetrahedron Lett.
1997,
38:
521
2d
Fuska J.
Fuskova A.
Proksa B.
Zb. Pr. Chemickotechnol. Fak. SVST
1979-1981 (pub. 1986),
285-291 ; Chem. Abstr. 1987, 106, 95582k
2e
Egbertson MS.
Hartman GD.
Gould RJ.
Bednar RA.
Cook JJ.
Gaul SL.
Holahan MA.
Libby LA.
Lynch RJ.
Sitko GR.
Stranieri MT.
Vassallo LM.
Bioorg. Med. Chem. Lett.
1996,
6:
2519
3a
Brever E.
Zbaida Z.
Tetrahedron Lett.
1975,
31:
499
3b
Inubushi Y.
Tsuda Y.
Konita T.
Matsumoto S.
Chem. Pharm. Bull.
1964,
12:
749
3c
Inubushi Y.
Tsuda Y.
Konita T.
Matsumoto S.
Chem. Pharm. Bull.
1968,
16:
1014
3d
Abramovitch RA.
Shinkai I.
Mavunkel BJ.
More KM.
O’Connor S.
Ooi GH.
Pennington WT.
Srinivason PC.
Stowers JR.
Tetrahedron
1996,
52:
3339
3e
Pigeon P.
Decroix B.
Tetrahedron Lett.
1997,
38:
2985
3f
Heaney H.
Shuhaibar KF.
Synlett
1995,
47
3g
Othman M.
Decroix B.
Synth. Commun.
1996,
2803
3h
Othman M.
Pigeon P.
Decroix B.
Tetrahedron
1997,
53:
2495
3i
Boger DL.
Lee JK.
Goldberg J.
Jin Q.
J. Org. Chem.
2000,
65:
1467
4
Hilt G.
Galbiati F.
Synlett
2005,
829
5 The starting materials for the cobalt-catalysed Diels-Alder reactions are easily accessed by a nucleophilic substitution/Sonogashira reaction sequence in good to excellent yields under standard reaction conditions.
6a
Pesquet A.
Daïch A.
Decroix B.
Van Hijfte L.
Org. Biomol. Chem.
2005,
3:
3937
6b
Cul A.
Daïch A.
Decroix B.
Sanz G.
Van Hijfte L.
Heterocycles
2004,
64:
33
6c
Decroix B.
Daïch A.
Marchalín Š.
Sikoraiová J.
Tetrahedron Lett.
2002,
43:
4747
6d
Decroix B.
Jilale A.
Daïch A.
Chihab-Eddine A.
Heterocycles
2002,
58:
449
6e
Decroix B.
Daïch A.
Hucher N.
J. Org. Chem.
2001,
66:
4695
6f
Decroix B.
Daïch A.
Hucher N.
J. Heteroat. Chem.
1998,
35:
1477
6g
Decroix B.
Pigeon P.
Marchalin Š.
Daïch A.
Tetrahedron Lett.
1998,
39:
9187
6h
Decroix B.
Pigeon P.
Tetrahedron Lett.
1998,
39:
8659
6i
Decroix B.
Pigeon P.
Othman M.
Tetrahedron
1998,
54:
8737
7
Decroix B.
Pigeon P.
Tetrahedron Lett.
1997,
38:
2985
8 The compounds 5f, 5i and 5j exhibit additional stereogenic centres and are therefore obtained as mixtures of diastereomers.