Title

Imidazolium Ion Tethered Tsdpens As Efficient Ligands for Iridium Catalyzed Asymmetric Transfer Hydrogenation of Ketophosphonates in Water

Author

Mengxia Sun

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Date of Award

Summer 2016

Abstract

In this thesis, a new water-compatible catalytic system, consist of imidazolium ion tethered TsDPENs (p-toluenesulfonyldiphenylethylenediamine) as ligands and Iridium as transition metal, has been developed to catalyze asymmetric transfer hydrogenation (ATH) of α-ketophosphonates. The reaction gives the desired product α-hydroxyphosphonates in moderate to good yields (44-78%) and good to excellent enantioselectivities (up to >99% ee). The mechanism of the ATH of α-ketophosphonates was proposed to explain the high enantioselectivity of the product. The enantiomeric excess was determined by 13P NMR by using (-)-cinchonidine as chiral solvating agent, which is a much more convenient method than chiral HPLC.

Advisor

Bukuo Ni

Subject Categories

Chemistry | Physical Sciences and Mathematics

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