TY - JOUR TI - Design and synthesis of chiral ligands and their application in transition metal-catalyzed asymmetric hydrogenations DO - https://doi.org/doi:10.7282/T3RV0R13 PY - 2016 AB - Transition metal catalyzed hydrogenations are among the most powerful and direct approaches for the synthesis of organic molecules. During the past half century, chiral ligands have been extensively studied in transition metal catalyzed transformations. Development of new chiral ligands, efficient catalyst systems and their applications in the reduction of various prochiral unsaturated substrates are the focus of this dissertation. In chapter 1, novel chiral tridentate f-amphox ligands were designed and synthesized. Two chiral wings in the ligands form a chiral pocket which introduces the chirality in the asymmetric hydrogenation. Tridentate f-amphox ligand has formed a highly enantioselective Iridium catalyst for direct hydrogenation of β-aryl β-ketoesters (up to 99% ee) and 3-oxo-3-arylpropionic acid ethyl esters (up to 99% ee) with high turnover number (up to 1,000,000). In chapter 2, I focus on the highly enantioselective direct reductive amination of aromatic ketone. With phenylhydrazide as the nitrogen source, various chiral hydrazides were synthesized in excellent enantioselectivities and yields. In chapter 3, a highly efficient enantioselective hydrogenation of N-alkyl-2-arylpyridinium salts was discussed. This work provides the unique example of using a chiral phosphole-based ligand for highly efficient asymmetric catalysis. The mechanism of this transformation was studied and a mechanistic cycle was proposed. KW - Chemistry and Chemical Biology KW - Hydrogenation LA - eng ER -