Abstract
A new method for the generation of C-2 centered radicals derived from 1,3-dithiane is presented. The radical precursors, 2-dialkylaminoxyl-1,3-dithianes, are readily prepared from 1,3-dithiane and stable nitroxides. Thermal reaction of 2-dialkylaminoxyl-1,3-dithianes with electron-deficient olefins affords carboaminoxylation products or oxidative addition products depending on the nitroxide used. The 2-dialkylaminoxyl-1,3-dithianes can also be used as initiators/regulators for the controlled living free radical polymerization of styrene.
Key words
radical chemistry - nitroxides - 1,3-dithianes - controlled radical polymerization - microwaves
References
1
Seebach D.
Corey EJ.
J. Org. Chem.
1975,
40:
231
2
Gröbel BT.
Seebach D.
Synthesis
1977,
357
3
Greene TW.
Wuts PGM.
Protecting Groups in Organic Synthesis
3th ed.:
Wiley;
New York:
1999.
4
Chatgilialoglu C.
Crich D.
Komatsu M.
Ryu I.
Chem. Rev.
1999,
99:
1991
5
Byers JH.
Whitehead CC.
Duff ME.
Tetrahedron Lett.
1996,
37:
2743
6
de Greef M.
Zard SZ.
Tetrahedron
2004,
60:
7781
7
Nishida A.
Kawahara N.
Nishida M.
Yonemitsu O.
Tetrahedron
1996,
52:
9713
8
Studer A.
Chem. Soc. Rev.
2004,
33:
267
9
Fischer H.
Chem. Rev.
2001,
101:
3581
10
Marque S.
Fischer H.
Baier E.
Studer A.
J. Org. Chem.
2001,
66:
1146
11
Hawker CJ.
Bosman AW.
Harth E.
Chem. Rev.
2001,
101:
3661
12
Ananchenko GS.
Fischer H.
J. Polym. Sci., Part A: Polym. Chem.
2001,
39:
3604
13
Connolly TJ.
Scaiano JC.
Tetrahedron Lett.
1997,
38:
1133
14a
Wetter C.
Studer A.
Chem. Commun.
2004,
174
14b
Teichert A.
Jantos K.
Harms K.
Studer A.
Org. Lett.
2004,
6:
3477
14c Review on microwave chemistry: Kappe CO.
Angew. Chem. Int. Ed.
2004,
43:
6250
15 The microwave experiments were conducted using professional laboratory microwave equipment. A MLS-Ethos 1600 Mikrowellen System (Milestone) was used for the present studies. The reactions were run in 40 mL MLS-reaction high-pressure vessels (up to 15 bars), which contain pressure control valves. An advanced temperature control system from MLS allowing direct contactless temperature monitoring was used. The microwave power is continuously and dynamically adjusted to follow the defined temperature profile.
16
Molawi K.
Schulte T.
Siegenthaler KO.
Wetter C.
Studer A.
Chem.-Eur. J. in press
17
Wetter C.
Gierlich J.
Knoop CA.
Müller C.
Schulte T.
Studer A.
Chem.-Eur. J.
2004,
10:
1156
18a
Schulte T.
Studer A.
Macromolecules
2003,
36:
3078
18b
Wetter C.
Gierlich J.
Knoop CA.
Müller C.
Schulte T.
Studer A.
Chem.-Eur. J.
2004,
10:
1156
19
Marque S.
Le Mercier C.
Tordo P.
Fischer H.
Macromolecules
2000,
33:
4403
20 This compound decomposes in the absence of solvents, upon exposure to air.
21
Jiang B.
Chen Z.
Tetrahedron: Asymmetry
2001,
12:
2835