General Papers ARKIVOC 2007 (i) 76-93
ISSN 1424-6376 Page 76
©
ARKAT USA, Inc.
Chemistry of polyhalogenated nitrobutadienes, 4:
reactions of mono-, bis-, and tris(4-tolylthio) derivatives of
2-nitroperchloro-1,3-butadiene with α,β-bifunctional nucleophiles
Viktor A. Zapol’skii,
a
Jan C. Namyslo,
a
Mimoza Gjikaj,
b
and Dieter E. Kaufmann
a*
a
Institute of Organic Chemistry, Clausthal University of Technology,
D-38678 Clausthal-Zellerfeld, Germany
b
Institute of Inorganic and Analytical Chemistry, Clausthal University of Technology,
D-38678 Clausthal-Zellerfeld, Germany
E-mail: dieter.kaufmann@tu-clausthal.de
Abstract
The reaction of 1-(4-tolylthio)-, 1,1-bis(4-tolylthio)-, or 1,1,3-tris(4-tolylthio)perchloro-2-nitro-
1,3-butadiene with α,β-bifunctionalized ethanes such as N,N-, N,O,-, N,S-, O,S-, S,S-, or O,O-
bisnucleophiles leads to both, highly functionalized 2-(1-nitroallylidene) derivatives of
imidazolidine, oxazolidine, thiazolidine, [1,3]oxathiolane, or [1,3]dithiolane, respectively, and to
the open chain, next higher thiolated buta-1,3-diene. The product distribution is highly sensitive
to modifications of the reaction conditions: apart from changes of molar ratios of substrates and
reagents the reaction temperature plays an important role. Thus, increase of the reaction
temperature favours formation of the 1,3-heterocyclic ring. In all cases, extensive spectroscopic
investigations have been performed and, in the case of the [1,3]oxathiolane also an X-ray
analysis.
Keywords: 2-Nitro-perchloro-1,3-butadiene, imidazolidine, thiol, vinylic substitution, nmr
spectroscopy, X-ray structure
Introduction
Due to their stepped reactivity in S
N
reactions, nitro-substituted polyhalogeno-1,3-butadienes
have proven to be valuable synthetic precursors for a variety of polyfunctionalized bioactive
heterocycles.
1,2
Often times, the building block of choice is 2-nitroperchloro-1,3-butadiene (1)
which is easily accessible by the introduction of an activating and directing nitro group into 2H-
pentachloro-1,3-butadiene. Synthetic use of 1 opens access to a quite diverse chemistry, the
documentation of which has been started by our group recently.
1
The preferred primary reaction
center of 1 is the activated terminal carbon atom C-1 of the nitrodichlorovinyl moiety. This