Research Projects

Electro-organic synthesis has recently gained renewed interest in synthetic organic chemistry due to several advantages. This technique employs electrode potential as a means to oxidize or reduce a species, rather than relying on chemical oxidants or reductants, which helps avoid the production of wasteful by-products. In many cases, it also eliminates the need for expensive metal-based catalysts. Furthermore, this methodology enables selective oxidation or reduction by targeting specific bonds one at a time, allowing for exceptional selectivity. However, there are challenges associated with electro-organic synthesis, including the following: (a) There has been insufficient focus on reducing the energy requirements for electrochemical synthesis; that is, finding efficient kinetic pathways to minimize the energy needed for a reaction to proceed. (b) Electro-organic synthesis methods can generate waste due to the use of high concentrations of electrolytes to ensure solution conductivity, prompting some scientists to argue that electrochemical methods are not environmentally friendly. (c) The deposition of synthesized molecules on the electrode surface during direct electrode oxidation leads to electrode passivation, which slows the reaction rate over time and significantly decreases Faradaic efficiency. (d) A smaller electrode surface area complicates large-scale synthesis. This research proposal aims to address these key issues through various examples of organic transformations, utilizing fundamental principles of physical and computational chemistry. Our research intends to employ Proton-Coupled Electron Transfer (PCET) and foundational electron transfer mechanisms to lower the kinetic barrier (i.e. reduction of applied potential), essentially reducing the energy requirement for selective organic transformations. Our primary focus will be on the dimerization or cyclization of 1,3-dicarbonyls to form different types of carbon-carbon bonds. These compounds are often core motifs found in natural products. We plan to use both direct electrode oxidation and electro-catalytic methods to synthesize the desired molecules. Various mechanistically distinct PCET mechanisms can be employed, including stepwise mechanisms (Proton Transfer (PT)-Electron Transfer (ET) or ET-PT), hydrogen atom transfer (HAT), multi-site concerted electron-proton transfer (MS-CEPT), hydride transfer (H-), etc. This proposal aims to systematically improve the energy efficiency of reactions by deeply understanding different PCET reaction mechanisms and utilizing various electro-catalysts. We will employ diverse electrochemical, spectroscopic, and spectro-electrochemical techniques to unravel PCET mechanisms. The energetics of the reaction mechanisms will be examined through computational calculations based on Density Functional Theory (DFT), providing deeper insights. One of the major focus of this research work will be to use electrochemistry/physical chemistry to quantify the kinetics of each of the direct electrode oxidation and electro-catalytic routes, which will help to improve our understanding of PCET pathways and provide a systematic route to enhance the kinetics towards lowering the power requirement for the reaction to carry out. By employing electro-catalytic methods, we aim to address the problem of electrode passivation to achieve sustained electrolysis and reduce reaction time. We will focus significantly on recovering electrolytes and catalysts to promote a greener synthesis process. Finally, we will attempt gram-scale synthesis to demonstrate the industrial applicability based on the fundamental understandings gained from this research by conducting syntheses employing the kinetically most inefficient and most efficient pathways as a proof of concept of this proposal.