A Novel Approach for Synthesis of Privileged Structural Motifs of Drug like Molecules

Abstract

A regioselective C2 arylation of indoles, benzothiophene and benzofuran without use of directing group has been accomplished using economically cheap Pd NPs and NHC-PdatMNPs catalyst. The reusable catalyst is efficiently employed to access C2 arylated heterocycles in good to excellent yield. The reusability of the catalyst is studied up to five cycles and a gram-scale synthesis has been achieved. The reaction mechanism is well supported by control experiments and literature precedents. newlineAn eco-friendly green method for one step synthesis of palladium nanoparticles and its synthetic utility has been described in this chapter. The phytochemicals like amines, alcohols, phenols present in the Areca Nut Husk extract facilitate the reduction of PdII to Pd0. The phytochemicals serve as stabilising agent and ligand for palladium reduction and the need of external ligand is avoided. The Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy of newly synthesized palladium nanoparticles revealed spherical shaped morphology. The catalytic activity of nanoparticles was tested for 1,2-difunctionalization of ynamides, Heck coupling, denitrogenative coupling of phenylhydrazine newlineand C H arylation of indole. Moreover, catalyst recyclability, control experiments, mechanistic elucidation, gram scale synthesis was elaborated. newlineEnvironmentally safe biogenic technique for in-situ one-step synthesis of Pd NPs decorated on carbon nanotubes and its synthetic utility has been disclosed for the first time. The phytochemicals found in Gliricidia sepium leaves extract were found to be serves as a reducing agent to reduce cationic palladium to Pd0 and subsequently acts as a stabilising agent. In addition, using Gaussian 09 software, DFT investigations of phytochemicals found in Gliricidia sepium leaves extract were conducted. The catalytic potential of synthesised catalyst was further investigated in the cost-effective synthesis of isoquinolones without the need of ligands using Pd-catalysed C H and N H activation. This method furnished many isoquinolone derivatives in good to excellent yields with high regioselectivity in the assistance of air as an oxidant. In addition catalyst recyclability, synthetic utility and mechanistic experiments were deliberated. newline newline