Selenium‐Containing Heterocycles from Isoselenocyanates: Base‐Catalyzed Reaction of Malononitrile with Phenyl Isoselenocyanate and Bromoacetonitrile or α‐Halogenated Ketones |
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| Authors: | Geoffroy L Sommen Anthony Linden Heinz Heimgartner |
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| Institution: | 1. Organisch‐Chemisches Institut der Universit?t Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, (phone: +41?44?635?4282;2. fax: +41?44?635?6836);3. Present address: Lonza Braine SA, Chaussée de Tubize 297, Batiment B8P2, 1420 Braine l'Alleud, Belgium;4. Postdoctoral stay at the University of Zürich (08.2004–08.2005) |
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| Abstract: | The reaction of phenyl isoselenocyanate ( 1a ) with malononitrile (=propanedinitrile) in DMF in the presence of Et3N leads to the intermediate ketene N,Se‐hemiacetal 6a , which can be trapped with bromoacetonitrile or α‐halogenated ketones 12a and 12b (Scheme 3). The products are (alkylseleno)(phenylamino)methylene]malononitriles 10 and 13 , which are obtained in good yield. In the case of the (2‐oxoalkyl)seleno derivatives 13 , they are in equilibrium with the cyclic hemiacetals 14 . Chemical and spectroscopic evidence for the structures of the new compounds are described. The structure of 14a was established by X‐ray crystallography. |
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| Keywords: | Isoselenocyanates Selenaheterocycles 1 3‐Selenazolidines Malononitrile X‐Ray crystallography |
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