Pseudo-multicomponent reactions

Abstract

Pseudo-MCRs are domino-type one-pot processes that involve combinations of at least three reactants (similarly to normal MCRs) but in which one of them is stoichiometrically duplicated (or more) and hence takes part into two reaction steps (or more).

Recent developments using malononitrile in ultrasound-assisted multicomponent synthesis of heterocycles

“…The mechanism involves the deprotonation of malononitrile by the base to form a carbanion, which then adds to the β-carbon of the unsaturated compound. The resulting intermediate then undergoes tautomerization to form the final product and regenerate the base [36] . The Gewald reaction is a chemical reaction that involves the formation of a thiophene ring from malononitrile, a ketone or an aldehyde, elemental sulfur, and a base.…”

“…The mechanism involves the deprotonation of malononitrile by the base to form a carbanion, which then adds to the β-carbon of the unsaturated compound. The resulting intermediate then undergoes tautomerization to form the final product and regenerate the base [36] .…”

“…Despite this, ultrasound has multiple practical applications in daily life, including sonar technology for navigation and echography for medical purposes ( Fig. 2 ) [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [26] . Fig.…”

4a′-Hydroxy-3′,3′,5,6′,6′,7-hexamethyl-3′,4′,4a′,6′,7′,9a′-hexahydrospiro[indole-3,9′-xanthene]-1′,2,8′(1H,2′H,5′H)-trione

“…The final compounds of pseudo-MCRs contain two or more components of the reagents [1]. Also, pseudo-MCRs are domino-type one-pot processes, equal to classical MCRs, but the stoichiometry for one or more reactants is duplicated, triplicated, or more [2]. However, pseudo-MCRs have some limitations in comparison to classical MCRs, such as less structural diversity and less functional flexibility, which are offset by the high molecular symmetry that can be achieved with them [3].…”

“…However, pseudo-MCRs have some limitations in comparison to classical MCRs, such as less structural diversity and less functional flexibility, which are offset by the high molecular symmetry that can be achieved with them [3]. Pseudo-MCRs have led to a variety of compounds with interesting biological properties, especially desirable in the pharmaceutical industry [2].…”