Design And Synthesis Of New Chiral Catalysts And Their Application In The Asymmetric Reactions

Asymmetric catalysis is one of the important methods for synthesizing chiral compounds, which are widely used in medicine, pesticide and novel material. As we all know, chiral catalyst plays the crucial role in asymmetric catalytic reaction and design and synthesis of new chiral catalysts have been one of the research hotspots in asymmetric chemistry. Based on this background, chiral spiroaminals were synthesized and the conjugate additions of hydroxylamines to unsaturated aldehydes were studied with chiral spiro-pyrrolidine as catalysts.The first chapter started by describing relevant literatures of spiroaminals focusing on their synthesis and properties.In our own research, we carried out several simple chemical conversions from natural amino acids and synthesized a series of chiral-diamine compounds.The second chapter reviewed the history and research progress of the organocatalytic asymmetric aza-1,4-additions and 1,6-additions. We successfully developed a spiro-pyrrolidine catalyzed aza-1,4-addition reaction between hydroxylamines and unsaturated aldehydes with broader substrate scope and higher enantioselectivity compared to previous reports. When the same type of reaction was extended to 2,4-dienals, a novel aza-1,6-addition was achieved. However, further investigations suggested that the regioselectivity depends largely on 2,4-dienals because of the competitive reactions between aza-1,4-additions and aza-1,6-additions.