A general and enantiodivergent method for the asymmetric synthesis of piperidine alkaloids: concise synthesis of (R)-pipecoline, (S)-coniine and other 2-alkylpiperidines
作者:Juan Etxebarria、Jose L. Vicario、Dolores Badía、Luisa Carrillo
DOI:10.1016/j.tet.2007.08.067
日期:2007.11
A simple and very efficient protocol for the preparation of highly enantioenriched 2-alkylpiperidines has been set up, which allows the preparation of the final heterocycles with any wanted configuration at the stereogenic center starting from the same starting material. The key step of the synthesis relies on a diastereodivergent aza-Michael reaction protocol using the readily available and cheap
Asymmetric Synthesis of β-Amino Esters by Aza-Michael Reaction of α,β-Unsaturated Amides Using (<i>S</i>,<i>S</i>)-(<i>+</i>)-Pseudoephedrine as Chiral Auxiliary
作者:Juan Etxebarria、Jose L. Vicario、Dolores Badia、Luisa Carrillo
DOI:10.1021/jo0357768
日期:2004.4.1
Chiral nonracemic β-amino esters were prepared in good yields and enantioselectivities using the diastereoselective conjugate addition of nitrogen nucleophiles to α,β-unsaturated amides derived from (S,S)-(+)-pseudoephedrine as the key step. In this way, several β-amino amide adducts were prepared using different conjugate acceptors and two different lithium benzylamides as nucleophiles. These adducts