Computational insights into proton and hydride transfer chemistry

Abstract

Hydride and proton transfer is one of the very basic reaction happens in chemistry and biology. This has been an effective means of initiating chemical reactions in many important chemical and biological processes. The knowledge of the role of the hydride and proton transfer reactions and its effect on the rate of the reaction can be of great value to chemists. However, there is still a need to study the influence of hydride transfer in important areas of research in main group chemistry such as hydrosilylation and hydroboration. Also, there is also need to study how proton transfer can initiate the asymmetric organocatalysis. Density functional theory (DFT) could be employed to provide insight into the role that the hydride and proton transfer plays in those very important reactions. The aim of this thesis is to study hydride transfer chemistry in main group catalysis and proton transfer chemistry in asymmetric organocatalysis. Main group reactions is a geninue alternative to transition metals. Thus, due to aforementioned reasons, coupled with a scarcity of computational investigations on these environmentally benign compounds, I have these investigations. I have studied the hydrosilylation reaction with tris(pentafluorophenyl)borane B(C6F5)3 as initiator proposing the new autocatalytic pathway. It was also necessary to predict the role of B(C6F5)3 in different chemical transformations. It can easily be decided whether B(C6F5)3 will act as catalyst or initiator based on the ion-pair separation energy. In further investigations, I have modeled stannylene and germylene catalysts for the hydroboration reaction. Using the new modeled catalyst a new improved mechanistic pathway has been investigated. Lastly, how proton transfer helps the asymmetric organocatalysis has been investigated. A new modeled has been proposed, based on the interaction of additive, catalysts, electrophile and nucleophile. Furthermore, TOF calculations, volume correction in the entropy, and NCI plot analyses have been employed in our investigations into the role of hydride and proton transfer in chemistry.