複素環系不斉補助剤を基盤とした精密な不斉制御空間の構築と不斉触媒反応への展開

点击翻译按钮获取中文摘要

The aim of this research is to establish the methodology for i) simple preparation of tricyclic 2-oxazolidinones and 2-imidazolidinones with conformational rigidity and steric congestion as extremely powerful chiral auxiliaries by catalytic resolution, and ii) excellent asymmetric reactions with bicyclic 2-amino alcohols and 1,2-diamines derived from the above tricyclic compounds.1. Easy access to highly efficient chiral auxiliaries by kinetic resolution :The optically active "roofed" 2-oxazolidinones and 2-imidazolidinones were readily obtained from kinetic resolution with oxazaborolidine catalysts, which is an alternative method for optical resolution with "MAC-acid" (2-exo-methoxy-1-apocamphanecarboxylic acid).2. Development of highly efficient chiral auxiliaries :Diastereoselectivity which is induced by the use of 2-imidazolidinone auxiliaries is greatly dependent on the N-substituents of the heterocycles, among which the bulky arenesulfonyl group is the moiety of choice. Reactions of this type afford an excellent level of diastereoselection in the methylation of N'-butyryl-2-imidazolidinones via the metal enolates.3. Development of highly efficient chiral amino alcohols :(1) chiral ligands : The chiral cis-2-aminoalcohols derived from ring-opening of the above tricyclic 2-oxazolidinones played a promising role in performing the high level of catalytic chiral discrimination (asymmetrization of meso-1,3-diacetyl-2-imidazolidinones).(2) chiral reactants : The alkoxide of the sterically congested 2-aminoalcohols served well as chiral discriminating agents for highly efficient dissymmetrization of meso-1,3-diacetyl-2-imidazolidinones.(3) C_2-symmetrical bis (oxazoline) ligands : The use of sterically congested C_2-symmetrical bis (oxazoline) ligands derived from the above amino alcohols provided the unexpected enantioselection for aldol reactions catalyzed by the Cu (II) complexes, which was an important findings for a design of new chiral synthetic processes.