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
Sodium Borohydride as the Only Reagent for the Efficient Reductive Alkylation of Malononitrile with Ketones and Aldehydes
作者:Robert E. Sammelson、Jason C. Dunham、Adam D. Richardson
DOI:10.1055/s-2006-926307
日期:——
malononitriles has been developed. In this method, sodium borohydride in isopropanol has a catalytic effect on the initial condensation between malononitrile and aldehydes or ketones at 0 °C. The sodium borohydride also simultaneously acts as a reagent and reduces the unsaturated intermediate formed in situ by the condensation. This simple reductive alkylation method effectively consumes all malononitrile
condensation–reduction approach, which was carried out in water, has been reported. Using Hantzsch esters as reducing agent, under the promotion of base, a variety of reduced Knoevenagel adducts could be easily prepared by direct alkylation of malononitrile, ethyl 2-cyanoacetate, and 2-(4-nitrophenyl)acetonitrile, respectively. Meanwhile, a gram-scale synthesis of the protocol was also realized with excellent
THE REACTIONS OF BENZYLIDENEMALONONITRILES AND β-NITROSTYRENES WITH<i>O</i>-PHENYLENEDIAMINE INCLUDING THE NEW ORGANIC REDOX REACTIONS BETWEEN THE OLEFINS AND 2-PHENYLBENZIMIDAZOLINES
The reactions of benzylidenemalononitriles and β-nitrostyrenes with o-phenylenediamine in ethanol at boiling temperature gave the reduced products of the olefins. The reactions were rationalized on the basis of the role of 2-phenylbenzimidazolines as a hydrogen donor.
Rh-Catalyzed One-Pot Reductive Alkylation of Malononitrile Under Transfer Hydrogenation Conditions
作者:Jiashou Wu、Huajiang Jiang
DOI:10.1080/00397911.2010.481741
日期:2011.3.28
Abstract Efficient synthesis of monosubstituted malononitriles was achieved by one-pot reductive alkylation of malononitrile with carbonyl compounds via [Cp*RhCl2]2-catalyzed transferhydrogenation reaction.