Synthesis 2008(2): 279-285  
DOI: 10.1055/s-2007-990945
PAPER
© Georg Thieme Verlag Stuttgart · New York

Monosubstituted Malononitriles: Efficient One-Pot Reductive Alkylations of Malononitrile with Aromatic Aldehydes

Fariba Tayyaria, Dwight E. Wooda, Phillip E. Fanwickb, Robert E. Sammelson*a
a Department of Chemistry, Ball State University, Muncie, IN 47306-0445, USA
Fax: +1(765)2856505 ; e-Mail: resammelson@bsu.edu;
b Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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Publikationsverlauf

Received 13 September 2007
Publikationsdatum:
07. Dezember 2007 (online)

Abstract

A powerful new one-pot method has been developed for the reductive alkylation of malononitrile with aromatic aldehydes. This new procedure has vastly improved the yield and efficiency of the process, and increased the scope of the aromatic aldehydes. Incorporating water as the catalyst in ethanol for the condensation step allows stoichiometric amounts of malononitrile and aldehyde to be employed. The reduction step takes place quickly and efficiently with sodium borohydride to give monosubstituted malononitriles via filtration or extraction. The product from 2-quinolinecarboxaldehyde quickly rearranges to a novel indolizine, while alkylation of the monosubstituted derivative provides an unsymmetrically disubstituted malononitrile that does not rearrange.

8

See reference 1a and references cited therein.

10

The X-ray data of 26 and 27 have been deposited at the Cambridge Crystallographic Database Centre under CCDC # 661126 and 661127, respectively. They can be retrieved from the web address http://www.ccdc.cam.ac.uk/products/csd/request/.

14

The reaction outcome for this example has no advantages over our previously reported work5 where condensation was not performed as a separate step.

15

No acid was added to work up reactions containing nitrogen containing heterocycles.