Chemoselective Henry reaction catalyzed by electro-generated base

Electrocatalytic Multicomponent Transformation of Aldehyde, 5‐Amino‐3‐methyl‐1‐phenylpyrazole and Dimedone: An Efficient Protocol for Substituted Pyrazolo[3,4‐b]quinolines

“…According to the literatures [18,21–23] and the above experimental facts, a possible reaction mechanism is deduced (as shown in Scheme 2). During the reaction, the formation of an ethoxylate anion initially occurred in situ by the deprotonation of a molecule of ethanol on the cathode.…”

“…Electrochemical synthesis is a traditional synthetic method and revives in recent decades. Highly reactive intermediates are obtained by the electron transfer between an electrode and the substrate or solvent molecules under mild conditions in electrochemical reactions, which avoids acid and bases as reducing or oxidizing agents and related waste by‐products [21] . Moreover, electrochemical synthesis has also made a lot of progress in practical applications, such as the electrochemical synthesis of spirodihydrofuran and cyclopenta[ b ]pyran derivatives [22–23] .…”

“…Highly reactive intermediates are obtained by the electron transfer between an electrode and the substrate or solvent molecules under mild conditions in electrochemical reactions, which avoids acid and bases as reducing or oxidizing agents and related waste by-products. [21] Moreover, electrochemical synthesis has also made a lot of progress in practical applications, such as the electrochemical synthesis of spirodihydrofuran and cyclopenta[b]pyran derivatives. [22][23] Both of the above reactions are initiated by an active base, which is generated by the transfer of electrons from the cathode to the substrate or solvent molecules.…”

The Henry Reaction in [Bmim][PF6]-based Microemulsions Promoted by Acylase

“…The Henry (nitroaldol) reaction is considered one of the most powerful and atom economical C–C bond-formation reactions and is widely employed in organic chemistry. The resulting products, β-nitro alcohols, are often used as key intermediates in the synthesis of numerous biologically active compounds, including natural products, insecticides, fungicides and antibiotics [1,2,3,4,5]. Therefore, a variety of catalysts have been developed for this reaction, and basic catalysts are the most common ones [1,4,6,7,8].…”

“…The resulting products, β-nitro alcohols, are often used as key intermediates in the synthesis of numerous biologically active compounds, including natural products, insecticides, fungicides and antibiotics [1,2,3,4,5]. Therefore, a variety of catalysts have been developed for this reaction, and basic catalysts are the most common ones [1,4,6,7,8]. However, this type of reaction is often complicated under strong alkaline conditions because of the unwanted side reactions, such as aldol, Michael and elimination reactions [6,9,10].…”