110-47-4Relevant articles and documents
-
Astle,Etherington
, p. 2871 (1952)
-
Effect of pressure on sterically congested cyanoalkylation reactions of alcohols
Jenner
, p. 4311 - 4317 (2002)
The pressure effect on the phosphine-catalyzed nucleophilic addition of alcohols to unsaturated nitriles is examined. As a general result, pressure promotes these reactions. Their sensitivity to pressure increases with increasing steric congestion of either the alcohol or the nitrile. Activation volumes are found to be very negative pointing not only to a late transition state, but essentially to a considerable electrostriction contribution depending on steric hindrance to ionization. This means that pressures favors formation of the carbanion and attack of the nitrile. The results highlight the synthetic utility of high pressure to remove steric inhibition.
Template catalysis by manganese pincer complexes: Oxa- and aza-Michael additions to unsaturated nitriles
Tang, Shan,Milstein, David
, p. 8990 - 8994 (2019)
Activation of CN bonds by metal-ligand cooperation provides a new route for the functionalization of nitriles. Herein, we report the electrophilic activation of unsaturated nitriles by dearomatized manganese pincer complexes for the oxa- and aza-Michael addition reactions under very mild and neutral conditions. Derivatives of acrylonitrile and allyl cyanide furnished the corresponding β-addition products by reacting with alcohols and amines. Mechanistically, the catalysis is mostly ligand based. Reaction of the dearomatized PNN-Mn complex with 2-pentenenitrile or 3-pentenenitrile furnished an enamido-Mn complex. The equilibrium between an enamido complex and a ketimido complex, and reversible C-C bond formation with the ligand are proposed to play central roles in the catalysis.
A metal-ligand cooperative pathway for intermolecular oxa-michael additions to unsaturated nitriles
Perdriau, Sébastien,Zijlstra, Douwe S.,Heeres, Hero J.,De Vries, Johannes G.,Otten, Edwin
, p. 4236 - 4240 (2015)
An unprecedented catalytic pathway for oxa-Michael addition reactions of alcohols to unsaturated nitriles has been revealed using a PNN pincer ruthenium catalyst with a dearomatized pyridine backbone. The isolation of a catalytically competent Ru-dieneamido complex from the reaction between the Ru catalyst and pentenenitrile in combination with DFT calculations supports a mechanism in which activation of the nitrile through metal-ligand cooperativity is a key step. The nitrile-derived Ru-N moiety is sufficiently Br?nsted basic to activate the alcohol and initiate conjugate addition of the alkoxide to the α,β-unsaturated fragment. This reaction proceeds in a concerted manner and involves a six-membered transition state. These features allow the reaction to proceed at ambient temperature in the absence of external base.
KOtBu-Catalyzed Michael Addition Reactions Under Mild and Solvent-Free Conditions
Thiyagarajan, Subramanian,Krishnakumar, Varadhan,Gunanathan, Chidambaram
supporting information, p. 518 - 523 (2020/02/04)
Designed transition metal complexes predominantly catalyze Michael addition reactions. Inorganic and organic base-catalyzed Michael addition reactions have been reported. However, known base-catalyzed reactions suffer from the requirement of solvents, additives, high pressure and also side-reactions. Herein, we demonstrate a mild and environmentally friendly strategy of readily available KOtBu-catalyzed Michael addition reactions. This simple inorganic base efficiently catalyzes the Michael addition of underexplored acrylonitriles, esters and amides with (oxa-, aza-, and thia-) heteroatom nucleophiles. This catalytic process proceeds under solvent-free conditions and at room temperature. Notably, this protocol offers an easy operational procedure, broad substrate scope with excellent selectivity, reaction scalability and excellent TON (>9900). Preliminary mechanistic studies revealed that the reaction follows an ionic mechanism. Formal synthesis of promazine is demonstrated using this catalytic protocol.
