Past and Present Research Systems of Green Chemistry

Biography

Biography: Brindaban C Ranu

Abstract

Metals play an important role as catalyst in organic synthesis and have been instrumental in many key transformations. Several noble and expensive metals such as platinum, gold, silver and palladium have been demonstrated to catalyze many important reactions. However, for better cost management and environmental concern use of less expensive and more environment friendly metals is desirable. Thus, the main focus of our group’s activity is directed to benign and inexpensive metal catalyzed C-C and carbon-heteroatom bond formation leading to the synthesis of bioactive molecules. For example, we have developed a recyclable heterogeneous catalyst of Cu(II) anchored on Al2O3 surface, that has been successfully used for several reactions. One of them is Cu(II)/Al2O3 catalyzed solvent controlled selective N-arylation of cyclic amides and amines leading to important scaffolds of potent therapeutic agents (Chem-Euro J., 2013, 19, 15759). We have also developed a novel concept of using two appropriate inexpensive metals in place of expensive metal like palladium and ligand, where one metal takes active part in catalysis and other one is assisting the process. Using this protocol copper-assisted nickel catalyzed ligand free Csp-Csp and Csp-Csp2 cross-coupling providing a direct access to unsymmetrical 1,3-diynes and en-ynes (Chem. Commun. 2014, 50, 15784), and Co/Cu catalyzed C(sp2)-O cross-coupling (Chem-Euro J. 2015, 21, 8727) have been achieved among others, Our another approach is to design metal free reaction which is traditionally mediated by metals. Thus, we have developed a visible light photocatalyzed direct conversion of aryl/heteroaryl amines to selenides at room temperature ( Org. Lett., 2014, 16, 1814)