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Others, however, insist that such a usage is an abuse of terminology, and limit the Michael addition to the formation of carbon–carbon bonds through the addition of carbon nucleophiles. The terms oxa-Michael reaction and aza-Michael reaction [2] have been used to refer to the 1,4-addition of oxygen and nitrogen nucleophiles, respectively. The ...
To manufacture a polyaspartic ester, an amine is reacted with dialkyl maleate by the aza-Michael reaction. [8]Diethyl maleate is the usual maleate used. This converts the primary amines to secondary amines and also introduces bulky groups to the molecule which causes steric hindrance, slowing the reaction down.
Mild conditions allow this reaction to take place while not affecting complex or reducible groups in the reactant-acid. [3] The reaction requires the presence of a nucleophile . A metal catalyst is required. Usually Ag 2 O is chosen but other metals and even light effect the reaction. [4] Arndt-Eistert reaction with ketene intermediate.
α,β-unsaturated carbonyl compounds undergo hydrocyanation in the absence of metal catalysts. One manifestation is a special case of the Michael reaction, leading to β-cyanoketones. Another manifestation leads to vinyl cyanohydrins. β-cyano-cyanohydrins are also observed. Reaction conditions allows access to any of these products. [7]
The quinidine-derived bifunctional organocatalyst 63 (first reported by Deng and co-workers) acts as a proficient catalyst for Michael addition reactions. [28] In this organocatalytic system, the H-bonding interaction arising from the quinoline alcohol is thought to be crucial for achieving high enantioselectivities.
Unlike classical catalysts, these organocatalysts interact by non-covalent interactions, especially hydrogen bonding ("partial protonation"). The scope of these small-molecule H-bond donors termed (thio)urea organocatalysis covers both non-stereoselective and stereoselective reactions.
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The Knorr pyrrole synthesis is a widely used chemical reaction that synthesizes substituted pyrroles (3). [1] [2] [3] The method involves the reaction of an α-amino-ketone (1) and a compound containing an electron-withdrawing group (e.g. an ester as shown) α to a carbonyl group (2). [4] The Knorr pyrrole synthesis