- Synthesis and Reactivity Profile of Ylidenemalononitrile Enamines and Their Ester Analogs Towards Electrophiles and Nucleophiles
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Herein, we describe the synthesis and reactivity of enamines derived from ylidenemalononitriles and ylidenecyanoacetates. The enamine scope was expanded by (1) increasing yields of aldehyde-derived ylidenemalononitriles, (2) incorporating silyl functional
- Longstreet, Ashley R.,Rivalti, Daniel,McQuade, D. Tyler
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- Facile metal free regioselective transfer hydrogenation of polarized olefins with ammonia borane
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Transfer hydrogenation of polarized olefins bearing strongly electron-withdrawing groups on one side of the double bond was achieved with ammonia borane under mild conditions without using a catalyst. Mechanistic studies proved the character of the direct H transfers proceeding stepwise with a unique hydroboration intermediate and hydride before proton transfer.
- Yang, Xianghua,Fox, Thomas,Berke, Heinz
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supporting information; experimental part
p. 2053 - 2055
(2011/03/22)
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- A convenient and selective one-pot method for the synthesis of monosubstituted secondary alkyl malononitriles
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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 NaBH 4 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.
- Sammelson, Robert E.,Allen, Mark J.
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p. 543 - 546
(2007/10/03)
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- Acids and bases in one pot while avoiding their mutual destruction
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Here is a solution to a classical problem: How to put, in one pot, both an acid and a base without their mutual destruction? The sol-gel materials method offers an approach: acids or bases are entrapped within these materials, and then organic reaction se
- Gelman, Faina,Blum, Jochanan,Avnir, David
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p. 3647 - 3649
(2007/10/03)
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- Geminal dinitriles and their reactions: I. Hydrolysis of alkylidene- and cycloalkylidenemalononitriles in aqueous medium
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The kinetics of pseudounimolecular hydrolysis of alkylidene- and cycloalkylidenemalononitriles in an aqueous buffer at pH 7 were studied. Correlations between the rate constants and substituent effects were found to fit the Taft-Hancock equation. Electrochemical reduction of alkylidenemalononitriles was studied using 0.2 M tetraethylammonium iodide as supporting electrolyte. The half-wave reduction potentials are related to the substituent constants σ* by the Taft-Zuman equation. Anomalous behavior of 1,1-dicyano-2,3,3-trimethyl-1-butene was observed during the hydrolysis and electrochemical reduction at a dropping mercury electrode.
- Smirnov,Sevast'yanova
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p. 1703 - 1708
(2007/10/03)
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- The Reaction between Diazoalkanes and Allylic Halides Carrying Electronegative γ-Substituents. 4. Conformational Equilibria of Highly Substituted 1-Pyrazolines
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Some di- and trisubstituted 1-pyrazoline-3-carbonitriles were synthesized and the coupling constants between vicinal protons were measured.In those cases where only one large substituent is present, the pseudoequatorial position is preferred.When two large groups are present trans to each other in vicinal position, the dipseudoaxial conformation is preferred.The compounds with preference for the dipseudoaxial conformation unexpectedly gave only cyclopropane derivatives when decomposed.
- Gulbrandsen, Trygve,Kolsaker, Per
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p. 219 - 226
(2007/10/02)
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