Effective Synthetic Strategies for the Construction of Isoquinoline Scaffold Found in Biologically Active Natural Products

Background: Alkaloids are a diverse group of naturally occurring secondary metabolites which exhibit various pharmacological properties. They have been synthesized via various synthetic routes in order to study their medicinal efficacy and structure activity relationships. Methodology: Keeping in view the pharmaceutical significance of this class of compounds, the present review has been written with a focus on the synthetic approaches used for efficient construction of isoquinoline scaffolds in natural alkaloids including crispine A, emetine, erythrocarine, jamatine, annosqualine, morphine, lemonomycin, papaverine, berberine, and codeine. Conclusion: The main goal behind the compilation of these schemes is to inspire organic chemists and help reinvigorate the development of novel strategies for the synthesis of isoquinoline alkaloids and their derivatives in the future. Keywords: Biologically active natural products, tetrahydroisoquinolines, morphine, Bischler Napieralski Reaction, Pictet-Spengler Reaction, natural alkaloids.