Sodium Borohydride as the Only Reagent for the Efficient Reductive Alkylation of Malononitrile with Ketones and Aldehydes.

Abstract

Nitriles P 0350Sodium Borohydride as the Only Reagent for the Efficient Reductive Alkylation of Malononitrile with Ketones and Aldehydes. -Primary and secondary substituted malononitriles are efficiently prepared via one-pot condensation between malononitrile and carbonyl compounds followed by NaBH4 reduction. -(DUNHAM, J. C.; RICHARDSON, A. D.; SAMMELSON*, R. E.; Synthesis 2006, 4, 680-686; Dep. Chem., Ball State Univ., Muncie, IN 47306, USA; Eng.) -Mais 25-078

Rh-Catalyzed One-Pot Reductive Alkylation of Malononitrile Under Transfer Hydrogenation Conditions

“…[6] Colorless liquid, column chromatography (silica gel, PE=EtOAc ¼ 5=1, R f ¼ 0. (1-Ethylpropyl)malononitrile (2n).…”

“…[6] Colorless liquid, column chromatography (silica gel, PE=EtOAc ¼ 5=1, Cyclohexylmalononitrile (2o). [6] Colorless liquid, column chromatography (silica gel, PE=EtOAc ¼ 5=1, R f ¼ 0. (1-Phenylethyl)malononitrile (2p).…”

“…(1-Phenylethyl)malononitrile (2p). [6] Colorless liquid, column chromatography (silica gel, PE=EtOAc ¼ 8=1, R f ¼ 0.43). 1 H NMR (200 MHz, CDCl 3 ): d ¼ 7.34-7.47 (m, 5H), 3.90 (d, J ¼ 6.1 Hz, 1H), 3.43-3.58 (m, 1H), 1.71 (d, J ¼ 7.0 Hz, 3H) ppm.…”

“…[6] However, in most cases the reaction proceeded with a large excess of carbonyl substrates, and the competitive carbonyl reduction was also a problem.…”

“…1 H NMR (200 MHz, CDCl 3 ): d ¼ 3.71 (t, J ¼ 7.6 Hz, 1H), 1.89-1.99 (m, 3H), 1.02 (d, J ¼ 6.2 Hz, 6H) ppm. 13 C NMR (50 MHz, CDCl 3 ): d ¼ 21.0, 21.7, 26.2, 39.3, 112.9 ppm.sec-Butylmalononitrile (2m) [6]. Colorless liquid, column chromatography (silica gel, PE=EtOAc ¼ 5=1, R f ¼ 0.42).…”