Ytterbium Triflate Catalyzed Synthesis of Alkoxy-Substituted Donor−Acceptor Cyclobutanes and Their Formal [4 + 2] Cycloaddition with Imines: Stereoselective Synthesis of Piperidines
作者:Mahmoud M. Abd Rabo Moustafa、Brian L. Pagenkopf
DOI:10.1021/ol102062t
日期:2010.11.5
A new synthesis of 2-alkoxy-1,1-cyclobutane diesters and their first use in dipolar cycloadditions is reported. Both the formation of the donor−acceptor cyclobutanes and their subsequent annulation with in situ formed imines are catalyzed by Yb(OTf)3. Cyclobutanes with carbon donor groups give piperidines with high trans stereoselectivity.