Transition metal-nanoparticles have emerged as one of the most versatile catalysts in organic synthesis. Homogeneous transition metal catalysts have been studied extensively in organic synthesis. However, the main problem with these catalysts is their poor recovery and reusability. Due to their lower reactivity, the application of heterogeneous catalysts in organic synthesis is also limited. Due to their semi heterogeneous nature, metal nanoparticles as catalysts have attracted interest.1 Nanoparticles catalytic activity has been found to be highly dependent on their size, stabilizers, and composition.2 In this context, to catalyze a wide variety of organic transformations, different types of transition metal nanoparticles have been developed. Chemo- and enantioselective reduction of α-keto amides to α-hydroxy amides using stable and reusable CuO-nanoparticles as a catalyst was developed.3a Further, a stable and reusable Pd/Cu-BNP bimetallic nanoparticles catalyzed the synthesis of hydroxyl isoindolones by C-H activation and annulation was also developed.3b An efficient, stable and reusable Pd-nanoparticles catalyzed synthesis of symmetrical and unsymmetrical 1,2-dicarbonyl compounds is also developed.3c Synthesis of 3-acyl-1-indenone derivatives from oxidative cyclization of aryldiynes using palladium nanoparticles (Pd-BNP) as a reusable catalyst is established.3d In all these reactions, the metal nanocatalyst was recovered and reused several times without any apparent loss in particle size and reactivity.
References
1. (a) A. Balanta, C. Godard, C. Claver, Chem. Soc. Rev. 2011, 40, 4973-4985. (b) G. Savitha, R. Saha, G. Sekar, Tetrahedron Lett. 2016, 57, 5168-5178. (c) M. Perez-Lorenzo, J. Phys. Chem. Lett. 2012, 3, 167-174.
2. (a) F. Mirkhalaf, J. Paprotny, D. J. Schiffrin, J. Am. Chem. Soc. 2006, 128, 7400-7401. (b) D. Ghosh, S. Chen, J. Mater. Chem. 2008, 18, 755-762. (c) R. N. Grass, E. K. Athanassiou, W. J. Stark. Angew. Chem. Int. Ed. 2007, 46, 4909-4912.
3. (a), G. N. Rao, G. Sekar (Manuscript under preparation). (b) G. N. Rao, G. Sekar (Manuscript under revision). (c) G. N. Rao, G. Sekar (Manuscript submitted). (d) G. N. Rao, G. Sekar (Manuscript under preparation).