One-pot multicomponent synthesis of thieno[2,3-b]indoles catalyzed by a magnetic nanoparticle-supported [Urea]₄[ZnCl₂] deep eutectic solvent

Abstract

We have developed the synthesis of thieno[2,3-b]indole dyes via a multicomponent reaction of cheap and available reagents using a magnetic nanoparticle-supported [Urea]4[ZnCl2] deep eutectic solvent as a green catalyst.

Recent Advances in the Synthesis of Heterocycles via Reactions Involving Elemental Sulfur

“…This step allowed migration of the electrophilic center to the end of acetophenone and reversed the regiochemistry of the reaction. [34] In a similar manner, cinnamic acid 91, which could involve in a decarboxylative Willgerodt pathway in DMF, displayed the same reactivity (Scheme 34). [35] A similar set of conditions involving a stoichiometric amount of molecular iodine was applied to cyclohexanones 93 (Scheme 35).…”

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

“…Further, Tran et al also reported the synthesis of 2-phenyl-8H-thieno[2,3-b]indoles (356) using 5-substituted indole (88a), sulfur, and 4-substituted acetophenone (77b) in DMF (Scheme 280). 508 The above one-pot synthesis was achieved using recyclable silica-coated magnetite NPs supported on a deep eutectic solvent (DES@MNP), where it acted as a Lewis acid catalyst via the Willgerodt-Kindler reaction to form thirenium intermediate, which reacted with 88a to form 356. The loading of the silica-coated Fe 3 O 4 NPs with urea and ZnCl 2 -derived deep eutectic solvent led to the formation of DES@MNP.…”

Synthetic Organic Transformations of Transition‐Metal Nanoparticles as Propitious Catalysts: A Review

“…It can be concluded that the nanoparticle catalyst could play significant role in reducing reaction times, ease of separation, ambient conditions and excellent yields of the products. [44] The catalyst was prepared by SiO 2 coating on Fe 3 O 4 followed by surface functionalization using (3-chloroprop- yl)triethoxysilane to afford Fe O @SiO 2 @(CH 2 ) Cl. To this was added DES at 100°C for hours to provide DES@MNP catalyst (Figure 7).…”