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
Organocatalytic asymmetric direct Michael addition of aromatic ketones to alkylidenemalononitriles
作者:Lei Yue、Wei Du、Yan-Kai Liu、Ying-Chun Chen
DOI:10.1016/j.tetlet.2008.04.069
日期:2008.6
The asymmetric direct Michael addition of aromatic ketones to highly active alkylidenemalononitriles was investigated by employing a chiral primary amine 9-amino-9-deoxyepicinchonine. In general modest to good enantioselectivities (71-84% ee) could be obtained in acceptable isolated yields (48-85%) for an array of substrates. (c) 2008 Elsevier Ltd. All rights reserved.
Back to Natural Cinchona Alkaloids: Highly Enantioselective Michael Addition of Malononitrile to Enones
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.