Date on Master's Thesis/Doctoral Dissertation
Committee Co-Chair (if applicable)
Micellar catalysis; palladium catalysis; chemistry in water; cross-coupling reactions; green chemistry; PS-750-M
The development and application of various micelle-enabled nanopalladium-catalyzed organic transformations are discussed in this dissertation. These methodologies primarily harness the “micellar effect” imparted by the custom-designed amphiphile PS-750-M. Modern spectroscopic and imaging techniques were employed to systematically study the metal-micelle interactions and answer the fundamental questions regarding the operational nature of micellar catalysis. Chapter 1 reviews the history and evolution of organic synthesis, providing a critical outlook regarding the alarming inefficiency of contemporary synthetic practices indicating an inevitable transition to more sustainable synthetic techniques. In this context, the development of micellar catalysis is discussed, emphasizing its basic principles, applications, and future directions and challenges. Chapter 2 discusses the development of a novel heterogeneous bimetallic nanocatalyst for the micellar Buchwald–Hartwig aminations. This highly recyclable catalyst was prepared by immobilizing the phosphine-bound Pd/Cu species on the charcoal surface. The broad scope of this approach was established by the coupling of various substrates, emphasizing the inclusion of challenging heterocycles. Chapter 3 describes the application of micelles's "shielding effect" towards the palladium-catalyzed α-arylation of acetonitriles with aryl halides under mild aqueous conditions. Detailed mechanistic studies using 31P NMR proved the involvement of carbanion-type species under reaction conditions. Chapter 4 & 5 explains our attempts to harness the structural features of PS-750-M amphiphile to stabilize Pd(II) and Pd(0) nanoparticles under ligand-free aqueous conditions. The activity of these amphiphile stabilized Pd nanoparticles were evaluated on base-free room temperature oxidative Heck couplings and Suzuki-Miyaura couplings of water-sensitive acid chlorides and aryl halides. Chapter 6 discusses the development of a novel palladium-catalyzed carboxylation technology, mediated by the cross-coupling of trichlorocarbanion with aryl halides under mild aqueous conditions. This methodology provides a unique route to access one or more atoms (O or C) isotope-enriched carboxylic acids. Chapter 7 describes a micelle-enabled strategy for the first C–N cross-coupling involving nitroarenes and aryl halides. This route proceeds through the domino amination of in-situ generated amines with aryl halides by surpassing the colossal challenge of dehalogenation. This is achieved by the rational design of a bimetallic nanocatalyst involving Pd and Cu
Nalakath, Tharique Ahammed Ansari, "Sustainable nanocatalysis in water for C–C and C–N Cross-Couplings." (2022). Electronic Theses and Dissertations. Paper 3828.