Catalytic Asymmetric Desymmetrization of Cyclic 1,3-Diketones Using Chiral Boro-phosphates
Minglei Chen1, Linfei Zhu1, Weitao Zheng1
1School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P. R. China.
Abstract:
Herein, we report a chiral boro-phosphate-catalyzed reductive amination for the desymmetrization of 2,2-disubstituted 1,3-cyclopentadiones with pinacolborane as the reducing agent, delivering chiral β-amino ketones with an all-carbon quaternary stereocenter in good yields (≤94%), high enantioselectivities (≤97% ee), and excellent diastereoselectivities (>20:1 dr). This reaction has a broad substrate scope and high functional group tolerance. The importance of the chiral products was also demonstrated through the preparation of multifunctional building blocks and heterocycles.
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