The Design And Synthesis Of Novel Chiral Dihydroimidazo Catalysts And Their Applications In The Kinetic Resolution Of Alcohols

Recently, Asymmetric acylation catalysts for the kinetic of secondary alcohols has been an active research topic, Some of which showed high efficioncy like dihydroimidazo based catalysts which displayed high efficiency and selectivity for the kinetic resolution of a series of secondary benzylic alcohols, and the entio-selectivity mainly depended on how strong are the cation-πandπ-πinteractions between the benzene ring of Substrate and the aromatic system of the catalyst. on this foundation, We designed and synthesized new chiral nucleophilic catalysts.This thesis maily focuaed on the design and synthesis of novel dihydroimidazo based catalysts for the kinetic of secondary alcohols, We designed and synthesised a series of new dihydroimidazo based catalysts, which would like to come true synergistic effect between the pseudo-arial chiral and center chiral to create the better chiral environment, and Their applications in kinetic of secondary alcohols are developed, Specifically including the following aspects:1 Design and synthesis of novel dihydroimidazole based nucleophilic catalystsL-phenylglycinol was used as chiral source, We respectively synthesised chiral catalyst 1-50 and axial chiral 1-48,1-49 based on the dihydroimidazo scaffold, and in the same way, We also synthesised dihydroimidazo based benzothiazole catalyst 1-51.2 The application of novel catalysts in the kinetic of secondary alcoholsThe catalysts I-48,I-49,I-50 and I-51 were tested in kinetic resolution of secondary benzylic alcohols, and it was demonstrated that 1-50 is an excellent catalyst, under the optimized conditions, Phenyl t-butyl carbinol was resolved with selectivity factor up to 456. Substitution of the aromatic ring was varied to investigate that p-substituted benzene ring substrates afford the better results with selectivity factor of 95.