Synthesis of substituted piperidines by enantioselective desymmetrizing intramolecular aza-Michael reactions
作者:Marta Guerola、Marcos Escolano、Gloria Alzuet-Piña、Enrique Gómez-Bengoa、Carmen Ramírez de Arellano、María Sánchez-Roselló、Carlos del Pozo
DOI:10.1039/c8ob01139g
日期:——
An organocatalytic enantioselective intramolecular aza-Michael reaction has been described for the first time in a desymmetrization process employing substrates different from cyclohexadienones. By using 9-amino-9-deoxy-epi-hydroquinine as the catalyst and trifluoroacetic acid as a co-catalyst, a series of enantiomerically enriched 2,5-and 2,6-disubstituted piperidines have been obtained in good yields
在使用与环己二酮不同的底物的去对称化方法中,首次描述了有机催化对映选择性分子内氮杂-迈克尔反应。通过使用9-氨基-9-脱氧-表氢对苯二酚作为催化剂,并使用三氟乙酸作为助催化剂,已经以高收率和适度的收率获得了一系列对映体富集的2,5-和2,6-二取代的哌啶非对映选择性。取决于催化剂/助催化剂的负载比,最终哌啶产物的主要或次要非对映异构体以高对映选择性实现。最后,通过理论计算考虑了一些机理上的见解,这些见解与在脱对称反应中获得的实验结果相吻合。