Synthesis of Benzoxazines by Heterogeneous Multicomponent Biochemo Multienzymes Cascade Reaction

Abstract

This work describes the possibility to combine multicomponent chemistry and multienzymes cascade transformations in a unique reactive framework to yield highly functionalized 1,4-benzoxazines under favorable heterogeneous conditions. The synthetic scheme involved the generation in situ of electrophilic reactive quinone intermediates of tyrosol esters catalyzed by lipase M and tyrosinase followed by nucleophilic 1,6-Michael addition of selected α-amino acid methyl esters, and successive intramolecular lactonization and aromatization processes. The immobilization of the multienzymes cascade on electroactive lignin nanoparticles improved the sustainability and recyclability of the overall system.

Multicomponent Click Reaction: An Indispensable Tool for Easy Access of Functionalized 1,2,3‐Triazoles

“…[8] The reactions enable the formation of complex molecular frameworks, such as functionalized 1,2,3triazoles, in a single step without the need for intermediate isolation or adjustment of reaction conditions. [9,10] This makes them invaluable tools in both combinatorial chemistry and clinical applications. Among the various strategies employed, copper-catalyzed azide-alkyne cycloaddition (CuAAC), [2,3,11] ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC), [12,13] strain-promoted azide-alkyne cycloaddition (SPAAC), [14] photoinduced click, [15] organocatalyzed 1,2,3-triazole forming click, [16][17][18][19][20] topochemical AAC, [21] and thermally triggered inter as well intramolecular versions of these reactions stand out.…”

One-Step Construction of 1,3,4-Oxadiazoles with Anticancer Activity from Tertiary Amines via a Sequential Copper(I)-Catalyzed Oxidative Ugi/aza-Wittig Reaction

“…However, it is worth noting the scarcity of documented instances involving the direct functionalization of tertiary amines, concomitant with the grafting of C-H bonds onto an in situ-generated heterocyclic framework. Isocyanide-based multicomponent reactions (IMCRs) have demonstrated a lot of promise in heterocyclic synthesis in recent years [ 27 , 28 , 29 , 30 ]. As the demand for synthetic chemistry in terms of atomic economy and high efficiency [ 31 ], IMCRs have gradually developed from the original Ugi reaction [ 32 , 33 ] to an oxidative Ugi reaction [ 34 ] through the process of the amine component’s in situ oxidation to the imine ion.…”