A highly efficient strategy for the kinetic resolution of Michael adducts was realized using a chiral N‐heterocyclic carbene catalyst. The kinetic resolution provides a new convenient route to single diastereomers of cyclohexenes and Michael adducts in good yields with high enantiomeric excesses (up to 99 % ee with a selectivity factor of up to 458). This “two flies with one swat” concept allows the
An efficient and convenient highly enantioselective Michaeladdition of malononitrile to enones has been developed by using quinine as the organocatalyst. The adducts were isolated in excellent yield and high asymmetric induction (up to 95% ee). An easy route to difficultly accessible ester derivatives has been also disclosed.
One-Pot Quinine-Catalyzed Synthesis of α-Chiral γ-Keto Esters: Enantioenriched Precursors of <i>cis</i>
-α,γ-Substituted-γ-Butyrolactones
作者:Sara Meninno、Chiara Volpe、Alessandra Lattanzi
DOI:10.1002/adsc.201600427
日期:2016.9.1
enantioselective one‐pot synthesis of important building blocks, α‐chiral γ‐keto esters, has been developed by combining a quinine‐catalyzed Michael addition of malononitrile to trans‐enones followed by magnesium monoperoxyphthalate (MMPP) oxidation. These synthons proved to be useful reagents for a simple access to challenging cis‐α,γ‐disubstituted γ‐butyrolactones in good diastereoselectivity and
Samarium(II) Iodide-Promoted Intermolecular and Intramolecular Ketone-Nitrile Reductive Coupling Reactions
作者:Longhu Zhou、Yongmin Zhang、Daqing Shi
DOI:10.1055/s-2000-6220
日期:——
Samarium(II) iodide, a strong one-electron transfer reducing reagent, has been successfully utilized for the intermolecular and intramolecular reductive coupling reactions of ketones with nitriles. α-Hydroxy ketones, monocyclic, fused bicyclic α-hydroxy ketones and monocyclic α-amino alcohols composed of a number of substitution patterns have been prepared in good yields at room temperature or reflux under neutral conditions. The procedure can avoid overreduction of the resulting of α-hydroxy ketones or α-amino alcohols. The crystal structures of monocyclic α-amino alcohols are reported.