A Convenient and Selective One-Pot Method for the Synthesis of Monosubstituted Secondary Alkyl Malononitriles
作者:Robert Sammelson、Mark Allen
DOI:10.1055/s-2004-837290
日期:——
We have found that α,α-dicyanoalkenes can be efficiently and selectively reduced to α,α-dicyanoalkanes (malononitriles) with NaBH4 in 95% EtOH at 0 °C. In addition, we have determined that the condensation of malononitrile with ketones using absorption alumina as a catalyst can be followed directly, in one pot, by reduction with NaBH4 in 95% EtOH at 0 °C to provide the monosubstituted secondary alkyl malononitriles in good to excellent yields (42-94%). This procedure provides a convenient alternative to direct alkylation of malononitrile or reduction of α,α-dicyanoalkene intermediates.
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
Stereospecific Syntheses of Enaminonitriles and β-Enaminoesters via Domino Ring-Opening Cyclization (DROC) of Activated Cyclopropanes with Pronucleophilic Malononitriles
作者:Amrita Saha、Aditya Bhattacharyya、Ranadeep Talukdar、Manas K. Ghorai
DOI:10.1021/acs.joc.7b03033
日期:2018.2.16
been developed via domino ring-opening cyclization (DROC) and DROC/decarboxylative tautomerization of activated cyclopropanes with malononitrile pronucleophiles, respectively. Both of the efficient strategies (yield up to 93%) have been generalized with various donor–acceptor and acceptor cyclopropanes as well as with malononitrile derivatives. The stereospecific variants of the two SN2-type DROC strategies
Selective Synthesis of Unsymmetrical Peroxides: Transition-Metal-Catalyzed Oxidation of Malononitrile and Cyanoacetic Ester Derivatives by tert-Butyl Hydroperoxide at the α-Position
malononitrile and cyanoaceticester derivatives at the α-position based on transition-metal-catalyzed reaction (Cu, Fe, Mn, Co) with tert-butyl hydroperoxide giving unsymmetrical peroxides in 63-94% yields. The method is facile, does not require large excesses of reagents, and is amenable to gram-scale synthesis. peroxides - tert-butyl hydroperoxide - catalysis - oxidation - transition metals - malononitrile