1060666-41-2Relevant academic research and scientific papers
Enantiopure 2,6-disubstituted piperidines bearing one alkene- or alkyne-containing substituent: Preparation and application to total syntheses of indolizidine-alkaloids
Liu, Hui,Su, Deyong,Cheng, Guolin,Xu, Jimin,Wang, Xinyan,Hu, Yuefei
supporting information; experimental part, p. 1899 - 1904 (2010/08/21)
A general and efficient procedure for the preparation of 2,6-disubstituted piperidines bearing one alkene- or alkyne-containing substituent was developed by using non-racemic Betti base as a chiral auxiliary. Many chiral benzylamines are excellent auxiliaries, but they were rarely used for this purpose because of the inefficient removal of the N-benzyl auxiliary residue under non-hydrogenative conditions. We found that N,N-disubstituted Betti base derivative has a typical Mannich structure of o-naphthol. When it carried out a base-catalyzed formation of o-quinone methide, an efficient non-hydrogenative N-debenzylation was achieved, and the alkene and alkyne groups survived. To demonstrate the efficiency of the method and the versatility of the products, asymmetric total syntheses of indolizidine-alkaloids (-)-167B, (-)-195H, (-)-209D and (-)-223AB were accomplished.
