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A cheap metal for a challenging task: nickel-catalyzed highly diastereo- and enantioselective hydrogenation of tetrasubstituted fluorinated enamides.

ABSTRACT: Nickel-catalyzed asymmetric hydrogenation of challenging tetrasubstituted fluorinated enamides has been achieved, affording chiral ?-fluoro-?-amino esters in high yields with excellent diastereo- and enantioselectivities (up to 98% yield, >99?:?1 dr, up to >99% ee). Deuterium-labeling experiments and control experiments were conducted to probe the mechanism, and the results indicated that the acidity of the solvent plays a critical role in the control of diastereoselectivity by trapping the adduct of nickel hydride to C[double bond, length as m-dash]C bonds via protonolysis, giving the hydrogenation product with stereospecific syn-selectivity. This protocol provides efficient access to chiral ?-fluoro-?-amino esters which have important potential applications in organic synthesis and medicinal chemistry.

SUBMITTER: Guan YQ

PROVIDER: S-EPMC6335620 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

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A cheap metal for a challenging task: nickel-catalyzed highly diastereo- and enantioselective hydrogenation of tetrasubstituted fluorinated enamides.

Guan Yu-Qing YQ Han Zhengyu Z Li Xiuxiu X You Cai C Tan Xuefeng X Lv Hui H Zhang Xumu X

Chemical science 20181016 1

Nickel-catalyzed asymmetric hydrogenation of challenging tetrasubstituted fluorinated enamides has been achieved, affording chiral α-fluoro-β-amino esters in high yields with excellent diastereo- and enantioselectivities (up to 98% yield, >99 : 1 dr, up to >99% ee). Deuterium-labeling experiments and control experiments were conducted to probe the mechanism, and the results indicated that the acidity of the solvent plays a critical role in the control of diastereoselectivity by trapping the addu ...[more]

PMID: 30746080

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