Effective construction of quaternary stereocenters by highly enantioselective α-amination of branched aldehydes
作者:Ji-Ya Fu、Xiao-Ying Xu、Yan-Chun Li、Qing-Chun Huang、Li-Xin Wang
DOI:10.1039/c0ob00406e
日期:——
A highly efficient enantioselectiveα-amination of branchedaldehydes with azadicarboxylates promoted by chiral proline-derived amide thiourea bifunctional catalysts was developed for the first time, affording the adducts bearing quaternary stereogenic centers with excellent yields (up to 99%) and enantioselectivities (up to 97% ee).
Chiral α-Arylethanamines: An Organocatalyst for the Enantioselective α-Amination of Branched Aldehydes
作者:Ji-Ya Fu、Qi-Lin Wang、Lin Peng、Yong-Yuan Gui、Fan Wang、Fang Tian、Xiao-Ying Xu、Li-Xin Wang
DOI:10.1002/ejoc.201201701
日期:2013.5
α-Arylethanamines were investigated as organocatalysts for the α-amination of branchedaldehydes with azodicarboxylates. Optimization identified (R)-1-(1-naphthyl)ethanamine (1g) as an effective and enantioselectiveorganocatalyst; multifunctional chiral quaternary amino aldehydes were successfully obtained in excellent yields (up to 99 %) and with excellent enantioselectivities (up to 98 % ee).
Proline-catalysed asymmetric amination of α,α-disubstituted aldehydes: synthesis of configurationally stable enantioenriched α-aminoaldehydes
作者:Henning Vogt、Sylvia Vanderheiden、Stefan Bräse
DOI:10.1039/b305465a
日期:——
Proline-catalysed amination of α,α-disubstituted racemic aldehydes with azodicarboxylates proceeds smoothly to give configurationally stable scalemic aldehydes and oxazolidinones in up to 86% ee.
β-tert-Butyl aspartate as an organocatalyst for the asymmetric α-amination of α,α-disubstituted aldehydes
作者:Alexis Theodorou、Giorgos N. Papadopoulos、Christoforos G. Kokotos
DOI:10.1016/j.tet.2013.04.103
日期:2013.7
The enantioselective alpha-amination reaction of alpha,alpha-disubstituted aldehydes can lead to a variety of enantioenriched amino aldehydes, amino alcohols, and amino acids. After screening a variety of amino acids and their derivatives, we identified a cheap, simple, commercially available aspartic acid derivative that can catalyze efficiently the reaction between alpha,alpha-disubstituted aldehydes and dialkyl azodicarboxylates. The reaction proceeds smoothly leading to the corresponding alpha-aminated adducts in moderate to quantitative yields and moderate to high enantioselectivities (up to 96% ee). Finally, the conversion of these adducts to alpha,alpha-disubstituted quaternary amino acids is also described. 2013 Elsevier Ltd. All rights reserved.
Primary amine catalyzed electrophilic amination of α,α-disubstituted aldehydes
Organocatalytic alpha-amination of alpha,alpha-disubstituted aldehydes promoted by 9-amino-(9-deoxy)-epi-quinine is described. alpha-Hydrazino aldehydes bearing a quaternary stereogenic center are obtained in good to excellent yields and enantioselectivities. (C) 2011 Elsevier Ltd. All rights reserved.