Preyssler catalyst: a heterogeneous polyacidic catalyst for the efficient synthesis of diverse bioactive heterocyclic scaffolds

Abstract

Synthesis of biologically promising heterocyclic scaffolds under greener conditions is one of the most promising areas of research today in organic chemistry. Heterogeneous catalysis has received greater attention versus homogeneous catalysis as it is much more beneficial in terms of reusability of the catalysts. Among many others, various heteropoly acids have been used as efficient heterogeneous catalysts for diverse organic transformations. In the present review, we have summarized the literature related to the synthesis of various biologically promising heterocyclic scaffolds utilizing a catalytic amount of one such efficient and reusable heteropoly acid, the Preyssler catalyst.

One‐Pot Three‐Component Synthesis of Biologically Promising Indenoquinoxaline Fused Spiroheterocycles Starting from 11H‐indeno[1,2‐b]quinoxalin‐11‐ones

“…Nayak et al [49] synthesized a series of chromenes fused spiroindenoquinoxaline pyrrolidine derivatives (34,35) via one-pot threecomponent reactions of 11H-indeno[1,2-b]quinoxalin-11-one (1), 2phenyl-3-nitro-2H-chromene (32) and L-proline (3) or L-phenylalanine (33) in ethanol under refluxed conditions (Figure 13). All the reactions required 3 hours to complete.…”

“…In continuation of our strong interest about various bioactive heterocyclic or spiroheterocyclic scaffolds, [31–40] in the following sections we have discussed a series of one‐pot three‐component reaction protocols for the synthesis of structurally diverse spiroheterocycles involving 11 H ‐indeno[1,2‐ b ]quinoxalin‐11‐one as one of the starting reactant under various reaction conditions.…”

“…[25] Multi-component reaction strategy is considered as economical as well as one of the greenest tool to synthesize various heterocyclic compounds for its multiple advantages such as operational simplicity, reduction of purification processes, high atom economy, energy efficiency and many more. [26][27][28][29][30] In continuation of our strong interest about various bioactive heterocyclic or spiroheterocyclic scaffolds, [31][32][33][34][35][36][37][38][39][40] in the following sections we have discussed a series of one-pot three-component reaction protocols for the synthesis of structurally diverse spiroheterocycles involving 11H-indeno [1,2-b]quinoxalin-11-one as one of the starting reactant under various reaction conditions.…”