Discovery, synthesis, and scale-up of efficient palladium catalysts useful for the modification of nucleosides and heteroarenes

Abstract

Nucleic acid derivatives are imperative biomolecules and are involved in life governing processes. The chemical modification of nucleic acid is a fascinating area for researchers due to the potential activity exhibited as antiviral and antitumor agents. In addition, these molecules are also of interest toward conducting useful biochemical, pharmaceutical, and mutagenic study. For accessing such synthetically useful structures and features, transition-metal catalyzed processes have been proven over the years to be an excellent tool for carrying out the various transformations with ease and under mild reaction conditions. Amidst various transition-metal catalyzed processes available for nucleoside modification, Pd-catalyzed cross-coupling reactions have proven to be perhaps the most efficient, successful, and broadly applicable reactions in both academia and industry. Pd-catalyzed C�C and C�heteroatom bond forming reactions have been widely used for the modification of the heterocyclic moiety in the nucleosides, although a single catalyst system that could address all the different requirements for nucleoside modifications isvery rare or non-existent. With this in mind, we present herein a review showcasing the recent developments and improvements from our research groups toward the development of Pd-catalyzed strategies including drug synthesis using a single efficient catalyst system for the modification of nucleosides and other heterocycles. The review also highlights the improvement in conditions or the yield of various bio-active nucleosides or commercial drugs possessing the nucleoside structural core. Scale ups wherever performed (up to 100 g) of molecules of commercial importance have also been disclosed. � 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).