Development and optimisation of transition metal and metal free catalytic reactions

In this thesis, Density Functional Theory (DFT) was used to study a series of catalytic reactions of Gold, Borane and Bismuth catalysts, which involve supporting synthetic studies including reaction scope or new catalyst development. All DFT calculations were undertaken by the candidate and all the experimental studies were done by the experimental groups of Professor Stephen Hashmi, Professor Rebecca Melen and A/prof Chris Hyland. In this thesis, Chapter 1 presents an introductory discussion on the fundamental computational approaches. Chapter 2 looks at a series of gold-catalysed reactions in four different sections as follows: “Dual Gold-Catalyzed Cycloaromatization of Unconjugated (E)- Enediynes”, “A Weak Dative Interaction to a Gold Carbene Intermediate Induces a Selectivity Switch”, “Different Selectivities in the Insertions into C(sp² )-H Bonds: Benzofulvenes by Dual Gold Catalysis Competition Experiments”, and “Gold-Catalyzed Regiospecific Annulation of Unsymmetrically Substituted 1,5-Diynes for the Precise Synthesis of Bispentalenes”. Chapter 3 investigates six reactions catalysed by borane including i) alkenylation reactions of aryl esters with diazo compounds, ii) Nalkylation of amines with aryl esters iii) stereoselective C–H insertion, cyclopropanation, and ring-opening reactions, iv) carbenium ion generation and autocatalytic pyrazole synthesis, v) selective diazo cross-coupling and vi) site-selective Csp³−Csp/Csp³−Csp² cross-coupling reactions using frustrated lewis pairs. This chapter also includes a comprehensive study on borane catalysed carbene generation from donor acceptor diazo compounds. Chapter 4 employing computational study, demonstrates how a bismuth(III) catalyst achieves greatest activation of organic Lewis bases in a catalytic reaction.