Asymmetric synthesis of axially chiral biaryls and fluoroallenes through rhodium-catalyzed enantioselective transformations

• Main Author: Ng, Jia Sheng
• Other Authors: Chiba Shunsuke
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Science::Chemistry
• Online Access: https://hdl.handle.net/10356/145520
• Institution: Nanyang Technological University

This thesis aims to explore the generation of axially chiral compounds through β- elimination reactions, building on the well-established rhodium-catalyzed conjugate addition protocol. Chapter one is an introduction that describes the definition of axial chirality and relevant terminologies. The history of axially chiral compounds was documented, along with their prevalence and importance. In addition, the β-elimination reactions are discussed in terms of their classification and mechanism. Furthermore, the foundation of classical rhodium-catalyzed asymmetric addition reactions is discussed in-depth, pertaining to its mechanistic and stereo-induction model. Chapter two uncovers a novel type of point-to-axial chirality transfer through β-alkoxide elimination, synthesizing axially chiral biaryls from enantioenriched rhodium-catalyzed hydroarylation products. Chapter three describes a novel type of rhodium-catalyzed reaction between organozinc reagent and alpha, alpha-difluoroalkynes to generate axially chiral fluoroallenes through enantioselective beta-fluoride elimination.