DEVELOPMENT OF A NEW CYCLOHEXYL FUSED SPIRO PHOSPHINE FOR ENANTIOSELECTIVE REACTIONS USING GAMMA-SUBSTITUTED ALLENOATES

Abstract

This thesis described the a new type of cyclohexyl fused spirobiindane derived phosphine, NUSIOC-Phos. This bulky catalyst showed high reactivity and enantioselective control in the domino reaction of pyrrolidine-2, 3-diones with gamma-substituted allenoates for the construction of hetero-spirotricyclic lactams. Further studies showed a kinetic resolution was involved in this reaction and many enantiomerically enriched gamma-substituted allenoates were obtained. Secondly, a highly enantiodivergent phosphine catalyzed Michael addition/isomerization and [3+2] annulation for the construction of functionalized 1, 3-conjugated dienes and cyclopentenes was achieved. With NUSIOC-Phos, allenoates reacted smoothly with aroyl acrylate to give a wide range of conjugated 1, 3-dienes. On the other hand, amino acids-based dipeptide phosphine led to the formation of cyclopentene in high yields and high ee. At last, a enantioselective chemodivergent phosphine catalyzed Michael addition and domino process for the construction of functionalized 1,3-conjugated dienes and cyclo-fused bicyclic acetals was developed. NUSIOC-Phos, gamma-substituted allenoates reacted smoothly with tri-carbonyl compounds to furnish a wide range of cyclo-fused bicyclic acetals which are commonly found structural motifs in numerous natural products. It is noteworthy that variation of functional groups from ketones to esters led to a Michael addition/isomerization process, providing functionalized 1, 3-conjugated dienes in high yields and high enantioselectivities.