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theses

Rhodium-catalyzed hydroformylation reaction is one of the most powerful homogeneous catalytic processes in the synthesis of aldehydes that can be widely applied in pharmaceuticals and fine chemicals. The design and synthesis phosphorus ligands combine with rhodium precursor used as catalysts is essentially important in the development of this reaction. This dissertation mainly focuses on the design, synthesis and application of efficient phosphorus ligands in rhodium-catalyzed hydroformylation. Asymmetric hydroformylation reaction (AHF), especially rhodium-catalyzed AHF has played a central role to construct chiral aldehydes in only one step. Although tons of chiral phosphorus ligands have been reported, few of them exhibited practicable enantioselectivities and regioselectivities. We report a new family of highly tunable bisphospholane ligands in the application of series of terminal and internal olefins, affording up to 88% for styrene derivatives, 93% ee for vinyl acetate derivatives, 93% ee for dihydrofuran and 96% for dihyropyrrole. A systematic screening different substituents on the ligand showed that ortho chloride on phenyl moiety was the successful structure, achieving the highest regio- and enantioselectivity. To expand the scope of substrates, especially the more challenging 1,1-disubstituted olefins, we first report the asymmetric hydroformylation of 1,1-disubstituted allylphthalimides by employing chiral ligand 1,2-bis[(2S,5S)-2,5-diphenylphospholano]ethane [(S,S)-Ph-BPE] to yield a series of beta-3-aminoaldehydes with up to 95% enantioselectivity. This asymmetric procedure provides an efficient alternative route to prepare chiral beta-3-amino acids and alcohols that are key structural elements of beta-aminobutyric acid. Hydroaminomethylation is the tandem reaction of hydroformylation/hydrogenation. This efficient reaction is utilized to build nitrogen-containing compounds, which are interesting in pharmaceutics and fine chemicals. In this chapter, we disclose the synthesis of 4-aryl-2,3-dihyropyrrole derivatives by rhodium-catalyzed intramolecular hydrominometylation reaction with up to 99% yield.

ETD_6625

Ph.D.

Includes bibliographical references

by Xin Zheng

doi:10.7282/T33R0VWM

ETD doctoral

The author owns the copyright to this work.